2019 |
Gomez-Jeria, J S; Segura, C; Carcamo-Vega, J J Methodological problems in the analysis of the Raman spectra of the paper of some postage stamps from Crete Artículo de revista Chemistry Research Journal, 4 , pp. 58-67, 2019, ISSN: 2455-8990. Resumen | Enlaces | BibTeX | Etiquetas: baseline correction, cellulose, Cretan Postage stamps, Crete, fluorescence, raman spectroscopy, smooth., Vancouver Raman algorithm @article{RN1007, title = {Methodological problems in the analysis of the Raman spectra of the paper of some postage stamps from Crete}, author = {J.S. Gomez-Jeria and C. Segura and J.J. Carcamo-Vega}, url = {https://www.researchgate.net/publication/332547457_A_Raman_analysis_of_the_paper_of_some_postage_stamps_from_Crete}, issn = {2455-8990}, year = {2019}, date = {2019-01-06}, journal = {Chemistry Research Journal}, volume = {4}, pages = {58-67}, publisher = {Leon Publications}, abstract = {A Raman spectroscopy study has been carried out with 633 and 768 nm laser lines to characterize three Cretan postage stamps. The first corresponds was issued by the Russian Empire Administration area and the other two belong to the 1905 Revolutionary Issues. The resulting Raman spectra are not of enough quality allowing a direct interpretation. Possible corrections to these spectra are, for example, the removal of the background fluorescence, the baseline correction and/or smooth. These tools are available in several spectroscopy software packages. The central question is the reliability of the spectra obtained after one or more corrections are applied. In order to begin creating a common procedure to treat all samples we ascribed only those bands that coincide with the cellulose calculated Raman frequencies. The first results suggest that it is necessary to carry out more studies with a significant number of samples before proposing a common treatment for all Raman spectra of postage stamps presenting fluorescence.}, keywords = {baseline correction, cellulose, Cretan Postage stamps, Crete, fluorescence, raman spectroscopy, smooth., Vancouver Raman algorithm}, pubstate = {published}, tppubtype = {article} } A Raman spectroscopy study has been carried out with 633 and 768 nm laser lines to characterize three Cretan postage stamps. The first corresponds was issued by the Russian Empire Administration area and the other two belong to the 1905 Revolutionary Issues. The resulting Raman spectra are not of enough quality allowing a direct interpretation. Possible corrections to these spectra are, for example, the removal of the background fluorescence, the baseline correction and/or smooth. These tools are available in several spectroscopy software packages. The central question is the reliability of the spectra obtained after one or more corrections are applied. In order to begin creating a common procedure to treat all samples we ascribed only those bands that coincide with the cellulose calculated Raman frequencies. The first results suggest that it is necessary to carry out more studies with a significant number of samples before proposing a common treatment for all Raman spectra of postage stamps presenting fluorescence. |
Gomez-Jeria, J S; Gutierrez, S; Surco-Luque, J; Clavijo, E; Reyes-Diaz, I A Characterization Of Cellulose In Seven Books Using Raman Spectroscopy In The 800-1800 cm-1 Range. Artículo de revista Research Journal of Pharmaceutical, Biological and Chemical Sciences., 10 , pp. 1565-1579, 2019, ISSN: 2455-8990. Resumen | Enlaces | BibTeX | Etiquetas: alum, carbonate, cellulose, gelatin, lignin, Paper composition, raman spectroscopy, rosin, sulfate, Vancouver Raman algorithm. @article{RN1008, title = {A Characterization Of Cellulose In Seven Books Using Raman Spectroscopy In The 800-1800 cm-1 Range.}, author = {J.S. Gomez-Jeria and S. Gutierrez and J. Surco-Luque and E. Clavijo and I. Reyes-Diaz}, url = {https://www.researchgate.net/publication/330521781_A_characterization_of_cellulose_in_seven_books_using_Raman_spectroscopy_in_the_800-1800_cm-1_range}, issn = {2455-8990}, year = {2019}, date = {2019-01-03}, journal = {Research Journal of Pharmaceutical, Biological and Chemical Sciences.}, volume = {10}, pages = {1565-1579}, publisher = {2010 RJPBCS}, abstract = {Raman spectroscopy was employed to study the non-printed area of a page of seven books printed in the 18th and 19th centuries. We employed the Vancouver Raman Algorithm to deal with the strong fluorescence background, obtaining spectra only in the 800 a 1800 cm-1 range. Two samples contain lignin, suggesting the presence of wood fibers. One sample (year 1799) contains only cellulose and gelatin. Two samples contain rosin. There are several Raman bands that we could not ascribe. Based on the results we propose a way to prepare the samples that could guarantee that the infrared and Raman spectra can be compared with confidence.}, keywords = {alum, carbonate, cellulose, gelatin, lignin, Paper composition, raman spectroscopy, rosin, sulfate, Vancouver Raman algorithm.}, pubstate = {published}, tppubtype = {article} } Raman spectroscopy was employed to study the non-printed area of a page of seven books printed in the 18th and 19th centuries. We employed the Vancouver Raman Algorithm to deal with the strong fluorescence background, obtaining spectra only in the 800 a 1800 cm-1 range. Two samples contain lignin, suggesting the presence of wood fibers. One sample (year 1799) contains only cellulose and gelatin. Two samples contain rosin. There are several Raman bands that we could not ascribe. Based on the results we propose a way to prepare the samples that could guarantee that the infrared and Raman spectra can be compared with confidence. |
Vásquez-Espinal, A; Yañez, O; Osorio, E; Areche, C; García-Beltrán, O; Ruiz, L M; Cassels, B K; Tiznado, W Theoretical Study of the Antioxidant Activity of Quercetin Oxidation Products Artículo de revista Frontiers in Chemistry, 7 (818), 2019, ISSN: 2296-2646. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN3_102, title = {Theoretical Study of the Antioxidant Activity of Quercetin Oxidation Products}, author = {A V\'{a}squez-Espinal and O Ya\~{n}ez and E Osorio and C. Areche and O Garc\'{i}a-Beltr\'{a}n and L M Ruiz and B.K. Cassels and W Tiznado}, url = {https://www.frontiersin.org/article/10.3389/fchem.2019.00818}, doi = {10.3389/fchem.2019.00818}, issn = {2296-2646}, year = {2019}, date = {2019-01-01}, journal = {Frontiers in Chemistry}, volume = {7}, number = {818}, abstract = {It was recently shown that, when tested in cellular systems, quercetin oxidized products (Qox) have significantly better antioxidant activity than quercetin (Q) itself. The main Qox identified in the experiments are either 2,5,7,3′,4′-pentahydroxy-3,4-flavandione (Fl) or its tautomer, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (Bf). We have now performed a theoretical evaluation of different physicochemical properties using density functional theory (DFT) calculations on Q and its main Qox species. The most stable structures (for Q and Qox) were identified after a structural search on their potential energy surface. Since proton affinities (PAs) are much lower than the bond dissociation enthalpies (BDEs) of phenolic hydrogens, we consider that direct antioxidant activity in these species is mainly due to the sequential proton loss electron transfer (SPLET) mechanism. Moreover, our kinetic studies, according to transition state theory, show that Q is more favored by this mechanism. However, Qox have lower PAs than Q, suggesting that antioxidant activity by the SPLET mechanism should be a result of a balance between proclivity to transfer protons (which favors Qox) and the reaction kinetics of the conjugated base in the sequential electron transfer mechanism (which favors Q). Therefore, our results support the idea that Q is a better direct antioxidant than its oxidized derivatives due to its kinetically favored SPLET reactions. Moreover, our molecular docking calculations indicate a stabilizing interaction between either Q or Qox and the kelch-like ECH-associated protein-1 (Keap1), in the nuclear factor erythroid 2-related factor 2 (Nrf2)-binding site. This should favor the release of the Nrf2 factor, the master regulator of anti-oxidative responses, promoting the expression of the antioxidant responsive element (ARE)-dependent genes. Interestingly, the computed Keap1-metabolite interaction energy is most favored for the Bf compound, which in turn is the most stable oxidized tautomer, according to their computed energies. These results provide further support for the hypothesis that Qox species may be better indirect antioxidants than Q, reducing reactive oxygen species in animal cells by activating endogenous antioxidants.}, keywords = {}, pubstate = {published}, tppubtype = {article} } It was recently shown that, when tested in cellular systems, quercetin oxidized products (Qox) have significantly better antioxidant activity than quercetin (Q) itself. The main Qox identified in the experiments are either 2,5,7,3′,4′-pentahydroxy-3,4-flavandione (Fl) or its tautomer, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (Bf). We have now performed a theoretical evaluation of different physicochemical properties using density functional theory (DFT) calculations on Q and its main Qox species. The most stable structures (for Q and Qox) were identified after a structural search on their potential energy surface. Since proton affinities (PAs) are much lower than the bond dissociation enthalpies (BDEs) of phenolic hydrogens, we consider that direct antioxidant activity in these species is mainly due to the sequential proton loss electron transfer (SPLET) mechanism. Moreover, our kinetic studies, according to transition state theory, show that Q is more favored by this mechanism. However, Qox have lower PAs than Q, suggesting that antioxidant activity by the SPLET mechanism should be a result of a balance between proclivity to transfer protons (which favors Qox) and the reaction kinetics of the conjugated base in the sequential electron transfer mechanism (which favors Q). Therefore, our results support the idea that Q is a better direct antioxidant than its oxidized derivatives due to its kinetically favored SPLET reactions. Moreover, our molecular docking calculations indicate a stabilizing interaction between either Q or Qox and the kelch-like ECH-associated protein-1 (Keap1), in the nuclear factor erythroid 2-related factor 2 (Nrf2)-binding site. This should favor the release of the Nrf2 factor, the master regulator of anti-oxidative responses, promoting the expression of the antioxidant responsive element (ARE)-dependent genes. Interestingly, the computed Keap1-metabolite interaction energy is most favored for the Bf compound, which in turn is the most stable oxidized tautomer, according to their computed energies. These results provide further support for the hypothesis that Qox species may be better indirect antioxidants than Q, reducing reactive oxygen species in animal cells by activating endogenous antioxidants. |
Suárez-Rozas, C; Simpson, S; Fuentes-Retamal, S; Catalán, M; Ferreira, J; Theoduloz, C; Mella, J; Cabezas, D; Cassels, B K; Yáñez, C; Castro-Castillo, V Antiproliferative and Proapoptotic Activities of Aza-Annulated Naphthoquinone Analogs Artículo de revista Toxicology in Vitro, 54 , pp. 375-390, 2019, ISSN: 0887-2333. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN8j, title = {Antiproliferative and Proapoptotic Activities of Aza-Annulated Naphthoquinone Analogs}, author = {C Su\'{a}rez-Rozas and S Simpson and S Fuentes-Retamal and M Catal\'{a}n and J Ferreira and C Theoduloz and J Mella and D Cabezas and B K Cassels and C Y\'{a}\~{n}ez and V Castro-Castillo}, url = {http://www.sciencedirect.com/science/article/pii/S0887233318305071}, doi = {https://doi.org/10.1016/j.tiv.2018.10.014}, issn = {0887-2333}, year = {2019}, date = {2019-01-01}, journal = {Toxicology in Vitro}, volume = {54}, pages = {375-390}, abstract = {1,4-Naphthoquinone derivatives have been widely documented with regard to their biological properties, and particularly their anticancer activities. In the 9,10-anthraquinone family, aza-annulation involving one of the carbonyl oxygen atoms has afforded more potent, possibly less toxic analogues. We recently carried out different modifications on the naphthoquinone skeleton to generate 3-chloro-2-amino- and 3-chloro-2-(N-acetamido)-1,4-naphthoquinone and 3,4-dihydrobenzo[f]quinoxalin-6(2H)-one derivatives. These three series of compounds were now tested against normal human fibroblasts and six human cancer cell lines. Some of the dihydrobenzoquinoxalinone derivatives were not only more potent than their 1,4-naphthoquinone counterparts, but also exhibited 10- to 14-fold selectivity between bladder carcinoma and normal cells and were equipotent with the non-selective reference drug used (etoposide). The fusion of an additional azaheterocycle to the 1,4-naphthoquinone nucleus modulates both the activity, selectivity and mechanism of action of the compounds. The electrochemical properties of selected compounds were evaluated in an attempt to correlate them with cytotoxic activity and mechanism of action. Finally, 3D-QSAR CoMFA and CoMSIA models were built on the AGS, J82, and HL-60 cell lines. The best models had values of r2pred = 0.815; 0.823 and 0.925. The main structural relationships found, suggest that acetylation and alkylation of the amino group with large groups would be beneficial for cytotoxic activity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 1,4-Naphthoquinone derivatives have been widely documented with regard to their biological properties, and particularly their anticancer activities. In the 9,10-anthraquinone family, aza-annulation involving one of the carbonyl oxygen atoms has afforded more potent, possibly less toxic analogues. We recently carried out different modifications on the naphthoquinone skeleton to generate 3-chloro-2-amino- and 3-chloro-2-(N-acetamido)-1,4-naphthoquinone and 3,4-dihydrobenzo[f]quinoxalin-6(2H)-one derivatives. These three series of compounds were now tested against normal human fibroblasts and six human cancer cell lines. Some of the dihydrobenzoquinoxalinone derivatives were not only more potent than their 1,4-naphthoquinone counterparts, but also exhibited 10- to 14-fold selectivity between bladder carcinoma and normal cells and were equipotent with the non-selective reference drug used (etoposide). The fusion of an additional azaheterocycle to the 1,4-naphthoquinone nucleus modulates both the activity, selectivity and mechanism of action of the compounds. The electrochemical properties of selected compounds were evaluated in an attempt to correlate them with cytotoxic activity and mechanism of action. Finally, 3D-QSAR CoMFA and CoMSIA models were built on the AGS, J82, and HL-60 cell lines. The best models had values of r2pred = 0.815; 0.823 and 0.925. The main structural relationships found, suggest that acetylation and alkylation of the amino group with large groups would be beneficial for cytotoxic activity. |
Simoneit, B; Oros, D; Jaffé, R; Didyk-Peña, A; Areche, C; Sepúlveda, B; Didyk, B Mulinane and Azorellane Diterpenoid Biomarkers by Gc-Ms from a Representative Apiaceae (Umbelliferae) Species of the Andes Artículo de revista Molecules, 24 (4), pp. 684-684, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN6l, title = {Mulinane and Azorellane Diterpenoid Biomarkers by Gc-Ms from a Representative Apiaceae (Umbelliferae) Species of the Andes}, author = {B Simoneit and D Oros and R Jaff\'{e} and A Didyk-Pe\~{n}a and C. Areche and B Sep\'{u}lveda and B Didyk}, url = {http://www.mdpi.com/1420-3049/24/4/684}, doi = {10.3390/molecules24040684}, year = {2019}, date = {2019-01-01}, journal = {Molecules}, volume = {24}, number = {4}, pages = {684-684}, abstract = { Extracts of bled resin from Azorella compacta, of the Azorelloideae family from the Andes (>4000 m), were analyzed by gas chromatography-mass spectrometry. The mass spectra of the dominant compounds of the resin and its hydrogenation products were documented. The most abundant compounds were oxygenated diterpenoids, namely mulinadien-20-oic (Δ11,13 and Δ11,14) acids, azorell-13-en-20-oic acid, 13α,14β-dihydroxymulin-11-en-20-oic acid, and azorellanol, with a group of azorellenes and mulinadienes. The mass spectra of the novel diterpenoid hydrocarbons with the azorellane and mulinane skeletons were also presented. This study documents the molecular diversity of these diterpenoid classes, and could be of great utility for future organic geochemical, environmental, archeological, pharmaceutical, and forensic chemistry studies. },keywords = {}, pubstate = {published}, tppubtype = {article} } <p>Extracts of bled resin from Azorella compacta, of the Azorelloideae family from the Andes (>4000 m), were analyzed by gas chromatography-mass spectrometry. The mass spectra of the dominant compounds of the resin and its hydrogenation products were documented. The most abundant compounds were oxygenated diterpenoids, namely mulinadien-20-oic (Δ11,13 and Δ11,14) acids, azorell-13-en-20-oic acid, 13α,14β-dihydroxymulin-11-en-20-oic acid, and azorellanol, with a group of azorellenes and mulinadienes. The mass spectra of the novel diterpenoid hydrocarbons with the azorellane and mulinane skeletons were also presented. This study documents the molecular diversity of these diterpenoid classes, and could be of great utility for future organic geochemical, environmental, archeological, pharmaceutical, and forensic chemistry studies.</p> |
Sáez-Briones, P; Castro-Castillo, V; Díaz-Véliz, G; Valladares, L; Barra, R; Hernández, A; Cassels, B K Aromatic Bromination Abolishes the Psychomotor Features and Pro-Social Responses of Mdma (“Ecstasy”) in Rats and Preserves Affinity for the Serotonin Transporter (Sert) Artículo de revista Frontiers in Pharmacology, 10 (157), 2019, ISSN: 1663-9812. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN10x, title = {Aromatic Bromination Abolishes the Psychomotor Features and Pro-Social Responses of Mdma (“Ecstasy”) in Rats and Preserves Affinity for the Serotonin Transporter (Sert)}, author = {P S\'{a}ez-Briones and V Castro-Castillo and G D\'{i}az-V\'{e}liz and L Valladares and R Barra and A Hern\'{a}ndez and B K Cassels}, url = {https://www.frontiersin.org/article/10.3389/fphar.2019.00157}, doi = {10.3389/fphar.2019.00157}, issn = {1663-9812}, year = {2019}, date = {2019-01-01}, journal = {Frontiers in Pharmacology}, volume = {10}, number = {157}, abstract = {The entactogen MDMA (3,4-methylenedioxy-methamphetamine, “Ecstasy”) exerts its psychotropic effects acting primarily as a substrate of the serotonin transporter (SERT) to induce a non-exocytotic release of serotonin. Nevertheless, the roles of specific positions of the aromatic ring of MDMA associated with the modulation of typical entactogenic effects, using analogs derived from the MDMA template, are still not fully understood. Among many possibilities, aromatic halogenation of the phenylalkylamine moiety may favor distribution to the brain due to increased lipophilicity, and sometimes renders psychotropic substances of high affinity for their molecular targets and high potency in humans. In the present work, a new MDMA analog brominated at C(2) of the aromatic ring (2-Br-4,5-MDMA) has been synthesized and pharmacologically characterized in vitro and in vivo. First, binding competition experiments against the SERT-blocker citalopram were carried out in human platelets and compared with MDMA. Besides, its effects on platelet aggregation were performed in platelet enriched human plasma using collagen as aggregation inductor. Second, as platelets are considered an appropriate peripheral model for estimating central serotonin availability, the functional effects of 2-Br-4,5-MDMA and MDMA on ATP release during human platelet aggregation were evaluated. The results obtained showed that 2-Br-4,5-MDMA exhibits higher affinity for SERT than MDMA and fully abolishes both platelet aggregation and ATP release, resembling the pharmacological profile of citalopram. Subsequent in vivo evaluation in rats at three dose levels showed that 2-Br-4,5-MDMA lacks all key MDMA-like behavioral responses in rats, including hyperlocomotion, enhanced active avoidance conditioning responses and increased social interaction. Taken together, the results obtained are consistent with the notion that 2-Br-4,5-MDMA should not be expected to be an MDMA-like substrate of SERT, indicating that aromatic bromination at C(2) modulates the pharmacodynamic properties of the substrate MDMA, yielding a citalopram-like compound.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The entactogen MDMA (3,4-methylenedioxy-methamphetamine, “Ecstasy”) exerts its psychotropic effects acting primarily as a substrate of the serotonin transporter (SERT) to induce a non-exocytotic release of serotonin. Nevertheless, the roles of specific positions of the aromatic ring of MDMA associated with the modulation of typical entactogenic effects, using analogs derived from the MDMA template, are still not fully understood. Among many possibilities, aromatic halogenation of the phenylalkylamine moiety may favor distribution to the brain due to increased lipophilicity, and sometimes renders psychotropic substances of high affinity for their molecular targets and high potency in humans. In the present work, a new MDMA analog brominated at C(2) of the aromatic ring (2-Br-4,5-MDMA) has been synthesized and pharmacologically characterized in vitro and in vivo. First, binding competition experiments against the SERT-blocker citalopram were carried out in human platelets and compared with MDMA. Besides, its effects on platelet aggregation were performed in platelet enriched human plasma using collagen as aggregation inductor. Second, as platelets are considered an appropriate peripheral model for estimating central serotonin availability, the functional effects of 2-Br-4,5-MDMA and MDMA on ATP release during human platelet aggregation were evaluated. The results obtained showed that 2-Br-4,5-MDMA exhibits higher affinity for SERT than MDMA and fully abolishes both platelet aggregation and ATP release, resembling the pharmacological profile of citalopram. Subsequent in vivo evaluation in rats at three dose levels showed that 2-Br-4,5-MDMA lacks all key MDMA-like behavioral responses in rats, including hyperlocomotion, enhanced active avoidance conditioning responses and increased social interaction. Taken together, the results obtained are consistent with the notion that 2-Br-4,5-MDMA should not be expected to be an MDMA-like substrate of SERT, indicating that aromatic bromination at C(2) modulates the pharmacodynamic properties of the substrate MDMA, yielding a citalopram-like compound. |
Polo, E; Morales-Bayuelo, A; Orozco-Ugarriza, M E; Henao, J A; Galdámez, A; Gutierrez, M Crystal Structure and Theoretical Studies of 2-Bromo-N-(2,4-Difluorobenzyl)Benzamide; Intermediate for the Synthesis of Phenanthridinone Artículo de revista Chemical Data Collections, 21 , pp. 100218, 2019, ISSN: 2405-8300. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN27k, title = {Crystal Structure and Theoretical Studies of 2-Bromo-N-(2,4-Difluorobenzyl)Benzamide; Intermediate for the Synthesis of Phenanthridinone}, author = {E Polo and A Morales-Bayuelo and M E Orozco-Ugarriza and J A Henao and A. Gald\'{a}mez and M Gutierrez}, url = {http://www.sciencedirect.com/science/article/pii/S2405830019300771}, doi = {https://doi.org/10.1016/j.cdc.2019.100218}, issn = {2405-8300}, year = {2019}, date = {2019-01-01}, journal = {Chemical Data Collections}, volume = {21}, pages = {100218}, abstract = {2-bromo-N-(2,4-difluorobenzyl)benzamide was synthesized in 92% yield by the reaction of commercial 2-bromobenzoic acid with (2,4-difluorophenyl)methanamine. The new title compound was characterized by 1H and 13C NMR, EI-MS and FT-IR. The crystal structure was stablished by single-crystal X-ray diffraction analysis. The colorless plates crystallized in monoclinic system, space group P21/n, with a = 15.1112(11) r{A}, b = 4.8926(3) r{A}, c = 17.4796(13) r{A}, β = 91.167(7)°, V = 1292.05(16) r{A}3 and Z = 4. The refinement converged to R1(F)= 0.0380, wR2(F2) = 0.1226 and S = 1.008. The supramolecular packing array involves NH⋅⋅⋅O hydrogen-bonds and C-Br⋅⋅⋅π intermolecular interactions. Theoretical calculation of the title compound was carried out with HF/6\textendash31 G, HF/6\textendash31G(d, p), DFT-B3LYP/6\textendash31 G, DFT-B3LYP/6\textendash31G(d, p), DFT-M02X/6\textendash31 G and DFT-M02X/6\textendash31G(d, p).}, keywords = {}, pubstate = {published}, tppubtype = {article} } 2-bromo-N-(2,4-difluorobenzyl)benzamide was synthesized in 92% yield by the reaction of commercial 2-bromobenzoic acid with (2,4-difluorophenyl)methanamine. The new title compound was characterized by 1H and 13C NMR, EI-MS and FT-IR. The crystal structure was stablished by single-crystal X-ray diffraction analysis. The colorless plates crystallized in monoclinic system, space group P21/n, with a = 15.1112(11) Å, b = 4.8926(3) Å, c = 17.4796(13) Å, β = 91.167(7)°, V = 1292.05(16) Å3 and Z = 4. The refinement converged to R1(F)= 0.0380, wR2(F2) = 0.1226 and S = 1.008. The supramolecular packing array involves NH⋅⋅⋅O hydrogen-bonds and C-Br⋅⋅⋅π intermolecular interactions. Theoretical calculation of the title compound was carried out with HF/6–31 G, HF/6–31G(d, p), DFT-B3LYP/6–31 G, DFT-B3LYP/6–31G(d, p), DFT-M02X/6–31 G and DFT-M02X/6–31G(d, p). |
Paredes-Gil, K; Mendizábal, F; Jaque, P Journal of Molecular Modeling, 25 (10), pp. 305, 2019, ISSN: 0948-5023. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN63, title = {Further Understanding of the Ru-Centered [2+2] Cycloreversion/Cycloaddition Involved into the Interconversion of Ruthenacyclobutane Using the Grubbs Catalysts from a Reaction Force Analysis}, author = {K Paredes-Gil and F. Mendiz\'{a}bal and P Jaque}, url = {https://doi.org/10.1007/s00894-019-4150-0}, doi = {10.1007/s00894-019-4150-0}, issn = {0948-5023}, year = {2019}, date = {2019-01-01}, journal = {Journal of Molecular Modeling}, volume = {25}, number = {10}, pages = {305}, abstract = {The chemical reactivity of the first- and second-generation Grubbs catalysts has always been a significant issue in olefin metathesis. In the present work, we study the [2+2] cycloreversion/cycloaddition and the alkylidene rotation involved into the interconversion of the ruthenacyclobutane intermediate, through the reaction force and reaction force constant analysis. It has been found that the structural contribution controls the barrier energy in the interconversion of ruthenacyclobutane via [2+2] cycloreversion/cycloaddition, which is slightly lower in the second generation of Grubbs catalysts while its electronic contribution is slightly higher, which unveils a major rigidity and donor/acceptor properties of the NHC. This finding explains a greater structural contribution in the rate constant. Moreover, on the basis of the reaction force constant, the process can be classified as “two-stage”-concerted reactions, noting a more asynchronous process when the first generation is used as a catalyst.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The chemical reactivity of the first- and second-generation Grubbs catalysts has always been a significant issue in olefin metathesis. In the present work, we study the [2+2] cycloreversion/cycloaddition and the alkylidene rotation involved into the interconversion of the ruthenacyclobutane intermediate, through the reaction force and reaction force constant analysis. It has been found that the structural contribution controls the barrier energy in the interconversion of ruthenacyclobutane via [2+2] cycloreversion/cycloaddition, which is slightly lower in the second generation of Grubbs catalysts while its electronic contribution is slightly higher, which unveils a major rigidity and donor/acceptor properties of the NHC. This finding explains a greater structural contribution in the rate constant. Moreover, on the basis of the reaction force constant, the process can be classified as “two-stage”-concerted reactions, noting a more asynchronous process when the first generation is used as a catalyst. |
Moris, S; Valencia-Gálvez, P; Mejía-López, J; Peña, O; Barahona, P; Galdámez, A (Cu)Tet(Cr2–Xsnx)Octs4–Ysey Spinels: Crystal Structure, Density Functional Theory Calculations, and Magnetic Behavior Artículo de revista Inorganic Chemistry, 58 (20), pp. 13945-13952, 2019, ISSN: 0020-1669. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN28l, title = {(Cu)Tet(Cr2\textendashXsnx)Octs4\textendashYsey Spinels: Crystal Structure, Density Functional Theory Calculations, and Magnetic Behavior}, author = {S Moris and P Valencia-G\'{a}lvez and J Mej\'{i}a-L\'{o}pez and O Pe\~{n}a and P Barahona and A. Gald\'{a}mez}, url = {https://doi.org/10.1021/acs.inorgchem.9b01853}, doi = {10.1021/acs.inorgchem.9b01853}, issn = {0020-1669}, year = {2019}, date = {2019-01-01}, journal = {Inorganic Chemistry}, volume = {58}, number = {20}, pages = {13945-13952}, abstract = {A new series of (Cu)tet[Cr2\textendashxSnx]octS4\textendashySey compounds was prepared by solid-state reaction at high temperature. Determination of the crystal structures by single-crystal X-ray diffraction revealed that CuCr1.0Sn1.0S2.1Se1.9, CuCr1.2Sn0.8S2.1Se1.9, CuCr1.3Sn0.7S2.2Se1.8, and CuCr1.5Sn0.5S2.2Se1.8 crystallize in a normal spinel-type structure (cubic Fd3m space group). The powder X-ray diffraction patterns and Rietveld refinements of nominal CuCr2\textendashxSnxS2Se2 (x = 0.2, 0.4, 0.6, 0.8, and 1.0) were consistent with single-crystal X-ray diffraction data. Raman scattering analysis revealed that the A1g, Eg, and three F2g vibrational modes were observed in the spectra. The signal at ∼382 cm\textendash1, corresponding to the A1g mode, is attributed to symmetrical stretching of the chalcogen bond with respect to the tetrahedral metal. The samples with x = 0.2 and 0.4 exhibited ferromagnetic behavior, characterized by large positive θ values of +261 and +189 K, respectively. In contrast, antiferromagnetic (AF) behavior was observed for CuCrSnS2Se2 with a N\'{e}el temperature (TN) of 18.8 K and a θ value of −36.0 K. Density functional theory (DFT) and effective magnetic moments (μeff/μtheo) experimentally measured showed that the Sn ion is in oxidation state of 4+, i.e., diamagnetic behavior. DFT calculations revealed that the most stable magnetic state of CuCr1.0Sn1.0S2Se2 was AF with exchange constants for first- and second-neighbor interactions of J1 = 56.22 cm\textendash1 and J2 = −33.88 cm\textendash1. Thus, the AF interactions between ferromagnetic chains in CuCr1.0Sn1.0S2Se2 originate from the presence of diamagnetic Sn cations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new series of (Cu)tet[Cr2–xSnx]octS4–ySey compounds was prepared by solid-state reaction at high temperature. Determination of the crystal structures by single-crystal X-ray diffraction revealed that CuCr1.0Sn1.0S2.1Se1.9, CuCr1.2Sn0.8S2.1Se1.9, CuCr1.3Sn0.7S2.2Se1.8, and CuCr1.5Sn0.5S2.2Se1.8 crystallize in a normal spinel-type structure (cubic Fd3m space group). The powder X-ray diffraction patterns and Rietveld refinements of nominal CuCr2–xSnxS2Se2 (x = 0.2, 0.4, 0.6, 0.8, and 1.0) were consistent with single-crystal X-ray diffraction data. Raman scattering analysis revealed that the A1g, Eg, and three F2g vibrational modes were observed in the spectra. The signal at ∼382 cm–1, corresponding to the A1g mode, is attributed to symmetrical stretching of the chalcogen bond with respect to the tetrahedral metal. The samples with x = 0.2 and 0.4 exhibited ferromagnetic behavior, characterized by large positive θ values of +261 and +189 K, respectively. In contrast, antiferromagnetic (AF) behavior was observed for CuCrSnS2Se2 with a Néel temperature (TN) of 18.8 K and a θ value of −36.0 K. Density functional theory (DFT) and effective magnetic moments (μeff/μtheo) experimentally measured showed that the Sn ion is in oxidation state of 4+, i.e., diamagnetic behavior. DFT calculations revealed that the most stable magnetic state of CuCr1.0Sn1.0S2Se2 was AF with exchange constants for first- and second-neighbor interactions of J1 = 56.22 cm–1 and J2 = −33.88 cm–1. Thus, the AF interactions between ferromagnetic chains in CuCr1.0Sn1.0S2Se2 originate from the presence of diamagnetic Sn cations. |
Moris, S; Barahona, P; Galdámez, A Crystal Structure of (Cu0.51in0.49)Tet[Cr1.74in0.26]Octse4 Selenospinel, Cu0.51in0.75cr1.74se4 Artículo de revista 234 (3), pp. 421, 2019, ISSN: 1433-7266. @article{RN33l, title = {Crystal Structure of (Cu0.51in0.49)Tet[Cr1.74in0.26]Octse4 Selenospinel, Cu0.51in0.75cr1.74se4}, author = {S Moris and P Barahona and A. Gald\'{a}mez}, url = {https://www.degruyter.com/view/journals/ncrs/234/3/article-p421.xml}, doi = {https://doi.org/10.1515/ncrs-2018-0426}, issn = {1433-7266}, year = {2019}, date = {2019-01-01}, volume = {234}, number = {3}, pages = {421}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Leal, M S; Briones, X; Villalobos, V; Queneau, Y; Leiva, A; Ríos, H E; Pavez, J; Silva, C P; Carrasco, C; Neira-Carrillo, A; Roth, A D; Tamayo, L; Immobilization, Enzyme Amino Acid-Functionalized Polyelectrolyte Films as Bioactive Surfaces for Cell Adhesion Artículo de revista ACS Applied Materials & Interfaces, 11 (22), pp. 19751-19762, 2019, ISSN: 1944-8244. Enlaces | BibTeX | Etiquetas: Amino Acid-Functionalized Polyelectrolyte Films, Bioactive Surfaces, Cell Adhesion @article{RN70, title = {Amino Acid-Functionalized Polyelectrolyte Films as Bioactive Surfaces for Cell Adhesion}, author = {M S Leal and X Briones and V Villalobos and Y Queneau and A Leiva and H E R\'{i}os and J Pavez and C P Silva and C Carrasco and A Neira-Carrillo and A D Roth and L. Tamayo and Enzyme Immobilization}, url = {https://doi.org/10.1021/acsami.9b02503}, doi = {10.1021/acsami.9b02503}, issn = {1944-8244}, year = {2019}, date = {2019-01-01}, journal = {ACS Applied Materials & Interfaces}, volume = {11}, number = {22}, pages = {19751-19762}, keywords = {Amino Acid-Functionalized Polyelectrolyte Films, Bioactive Surfaces, Cell Adhesion}, pubstate = {published}, tppubtype = {article} } |
Kpotin, G A; Bédé, A L; Houngue-Kpota, A; Anatovi, W; Kuevi, U A; Atohoun, G S; Mensah, J -B; Gomez-Jeria, J S; Badawi, M Relationship between Electronic Structures and Antiplasmodial Activities of Xanthone Derivatives: A 2d-Qsar Approach Artículo de revista Structural Chemistry, 30 (6), pp. 2301-2310, 2019, ISSN: 1572-9001. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN36j, title = {Relationship between Electronic Structures and Antiplasmodial Activities of Xanthone Derivatives: A 2d-Qsar Approach}, author = {G A Kpotin and A L B\'{e}d\'{e} and A Houngue-Kpota and W Anatovi and U A Kuevi and G S Atohoun and J -B Mensah and J.S. Gomez-Jeria and M Badawi}, url = {https://doi.org/10.1007/s11224-019-01333-w}, doi = {10.1007/s11224-019-01333-w}, issn = {1572-9001}, year = {2019}, date = {2019-01-01}, journal = {Structural Chemistry}, volume = {30}, number = {6}, pages = {2301-2310}, abstract = {Malaria is an important disease causing many death in several countries of Africa and Asia. In these continents, some plants such as Garcinia cola are used to fight against this disease because they contain xanthone derivatives which present antiplasmodial activity. The present theoretical study aims to establish a relationship between the electronic structure and the antiplasmodial activity of some xanthone derivatives, and more specifically to build a 2D-pharmacophore model in order to predict the biological activity of xanthone derivatives. The calculations are performed within the density functional theory (DFT) using the B3LYP/6-31G(d,p) level of theory. The developed approach quantitative structure-activity relationship (QSAR) follows the Klopman-Peradejordi-G\'{o}mez (KPG) methodology. We obtain a statistically significant equation relating the variation of the logarithm of half maximal inhibitory concentration (log(IC50)) with the variation of the numerical values of a set of eight local atomic reactivity descriptors (R = 0.98, R2 = 0.97, adj-R2 = 0.95, F(8.13) = 48.63, p < 0.00000, SD 0.08). The antiplasmodial activity seems to be driven by atomic orbitals and charges. Our 2D-pharmacophore model should be useful to propose new xanthone derivatives with higher antiplasmodial activity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Malaria is an important disease causing many death in several countries of Africa and Asia. In these continents, some plants such as Garcinia cola are used to fight against this disease because they contain xanthone derivatives which present antiplasmodial activity. The present theoretical study aims to establish a relationship between the electronic structure and the antiplasmodial activity of some xanthone derivatives, and more specifically to build a 2D-pharmacophore model in order to predict the biological activity of xanthone derivatives. The calculations are performed within the density functional theory (DFT) using the B3LYP/6-31G(d,p) level of theory. The developed approach quantitative structure-activity relationship (QSAR) follows the Klopman-Peradejordi-Gómez (KPG) methodology. We obtain a statistically significant equation relating the variation of the logarithm of half maximal inhibitory concentration (log(IC50)) with the variation of the numerical values of a set of eight local atomic reactivity descriptors (R = 0.98, R2 = 0.97, adj-R2 = 0.95, F(8.13) = 48.63, p < 0.00000, SD 0.08). The antiplasmodial activity seems to be driven by atomic orbitals and charges. Our 2D-pharmacophore model should be useful to propose new xanthone derivatives with higher antiplasmodial activity. |
Hermosilla, V; Vila, I; Copaja, S Lithium and Boron of Spring Water and Salt Crust from Salar De Ascotán, Southwestern Altiplano Artículo de revista Journal of the Chilean Chemical Society, 64 (3), pp. 4538-4541, 2019. @article{RN22k, title = {Lithium and Boron of Spring Water and Salt Crust from Salar De Ascot\'{a}n, Southwestern Altiplano}, author = {V Hermosilla and I Vila and S. Copaja}, url = {http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072019000304538&lng=en&nrm=iso&tlng=en}, doi = {10.4067/S0717-97072019000304538}, year = {2019}, date = {2019-01-01}, journal = {Journal of the Chilean Chemical Society}, volume = {64}, number = {3}, pages = {4538-4541}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Guerrero-Castillo, P; Reyes, S; Robles, J; Simirgiotis, M J; Sepulveda, B; Fernandez-Burgos, R; Areche, C Biological Activity and Chemical Characterization of Pouteria Lucuma Seeds: A Possible Use of an Agricultural Waste Artículo de revista Waste Management, 88 , pp. 319-327, 2019, ISSN: 0956-053X. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN2_105, title = {Biological Activity and Chemical Characterization of Pouteria Lucuma Seeds: A Possible Use of an Agricultural Waste}, author = {P Guerrero-Castillo and S Reyes and J Robles and M J Simirgiotis and B Sepulveda and R Fernandez-Burgos and C. Areche}, url = {http://www.sciencedirect.com/science/article/pii/S0956053X19301886}, doi = {https://doi.org/10.1016/j.wasman.2019.03.055}, issn = {0956-053X}, year = {2019}, date = {2019-01-01}, journal = {Waste Management}, volume = {88}, pages = {319-327}, abstract = {Pouteria lucuma fruit is widely used to prepare cakes, ice creams and juice or also commercialized as pulp and flour. As result of this business thousands of tons of seeds are generated as an agricultural waste. This study presents the antioxidant and antiulcer activities, and the identification of secondary metabolites by UHPLC/ESI/MS/MS of an agroindustrial waste of Pouteria lucuma seeds. Fifty-nine compounds were tentatively identified including eight aminoacids, five organic acids, one nucleoside, five phenolic acids, five phenolic alcohols, nineteen flavonoids, six lipids, and seven unknowns in the methanol extract of P. lucuma seeds. The total phenolic content of the seeds was 52.82 ± 0.09 μmol GAE/g dry weight, while total flavonoid content was 5.99 ± 0.01 μmol Q/g dry weight. The antioxidant activity was 58.14 ± 0.05, 66.97 ± 0.00, 272.50 ± 0.00, and 67.02 ± 2.23 for the DPPH, ABTS, FRAP, and superoxide anion assays, respectively. The highest gastroprotective activity was obtained at 100 mg/kg (78%), which as higher than the positive control lansoprazole (75%). Our findings showed that P. lucuma seed extracts have moderate to high antioxidant activity and gastroprotective properties. Therefore, it was demostrated that lucuma seeds commonly eliminated as an agricultural industry waste, could be useful for the preparation of nutritional supplements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pouteria lucuma fruit is widely used to prepare cakes, ice creams and juice or also commercialized as pulp and flour. As result of this business thousands of tons of seeds are generated as an agricultural waste. This study presents the antioxidant and antiulcer activities, and the identification of secondary metabolites by UHPLC/ESI/MS/MS of an agroindustrial waste of Pouteria lucuma seeds. Fifty-nine compounds were tentatively identified including eight aminoacids, five organic acids, one nucleoside, five phenolic acids, five phenolic alcohols, nineteen flavonoids, six lipids, and seven unknowns in the methanol extract of P. lucuma seeds. The total phenolic content of the seeds was 52.82 ± 0.09 μmol GAE/g dry weight, while total flavonoid content was 5.99 ± 0.01 μmol Q/g dry weight. The antioxidant activity was 58.14 ± 0.05, 66.97 ± 0.00, 272.50 ± 0.00, and 67.02 ± 2.23 for the DPPH, ABTS, FRAP, and superoxide anion assays, respectively. The highest gastroprotective activity was obtained at 100 mg/kg (78%), which as higher than the positive control lansoprazole (75%). Our findings showed that P. lucuma seed extracts have moderate to high antioxidant activity and gastroprotective properties. Therefore, it was demostrated that lucuma seeds commonly eliminated as an agricultural industry waste, could be useful for the preparation of nutritional supplements. |
Giordano, A; Fuentes-Barros, G; Castro-Saavedra, S; González-Cooper, A; Suárez-Rozas, C; Salas-Norambuena, J; Acevedo-Fuentes, W; Leyton, F; Tirapegui, C; Echeverría, J; Claros, S; Cassels, B K Variation of Secondary Metabolites in the Aerial Biomass of Cryptocarya Alba Artículo de revista Natural Product Communications, 14 (6), pp. 1934578X19856258, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN12l, title = {Variation of Secondary Metabolites in the Aerial Biomass of Cryptocarya Alba}, author = {A Giordano and G Fuentes-Barros and S Castro-Saavedra and A Gonz\'{a}lez-Cooper and C Su\'{a}rez-Rozas and J Salas-Norambuena and W Acevedo-Fuentes and F Leyton and C Tirapegui and J Echeverr\'{i}a and S Claros and B K Cassels}, url = {https://journals.sagepub.com/doi/abs/10.1177/1934578X19856258}, doi = {10.1177/1934578x19856258}, year = {2019}, date = {2019-01-01}, journal = {Natural Product Communications}, volume = {14}, number = {6}, pages = {1934578X19856258}, abstract = {Cryptocarya alba is an important tree species in the Chilean sclerophyllous forest. Its leaves and bark are used in traditional medicine to treat liver diseases and rheumatism. Analyses of the essential oil (EO) show serious discrepancies, and information on other constituents is limited. The aerial biomass of individual trees from 3 wild populations, some old trees, and farmed saplings were analyzed (n = 132). The EO profiles were studied by gas chromatography/mass spectrometry (GC/MS). The alkaloidal and polyphenol compositions were determined by ultra-high-performance liquid chromatography (UHPLC)/MS-MS. The total polyphenol content, the total flavonoid content, and the antioxidant capacity (diphenylpicrylhydrazyl, azinobisethylbenzothiazolinesulfonic acid, and ferric reducing antioxidant power: DPPH, ABTS, and FRAP respectively) were determined by standard methods. Significant differences were found at the individual and population levels in the contents of polyphenols, total flavonoids, antioxidant capacity, and specific alkaloids for leaves, bark, and wood. Farmed saplings grown under less light showed higher concentrations of higenamine, N-methylcoclaurine, N-methyllaurotetanine, and isocorydine, while those receiving more light were richer in laurolitsine, boldine, coclaurine, catechin, quercetin, epicatechin, quercitrin, and procyanidins. Important variations were found according to the season, age of the tree and of the leaves. The EO composition also varied considerably. These results support the idea that the natural variability of medicinal species is an important subject for study.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cryptocarya alba is an important tree species in the Chilean sclerophyllous forest. Its leaves and bark are used in traditional medicine to treat liver diseases and rheumatism. Analyses of the essential oil (EO) show serious discrepancies, and information on other constituents is limited. The aerial biomass of individual trees from 3 wild populations, some old trees, and farmed saplings were analyzed (n = 132). The EO profiles were studied by gas chromatography/mass spectrometry (GC/MS). The alkaloidal and polyphenol compositions were determined by ultra-high-performance liquid chromatography (UHPLC)/MS-MS. The total polyphenol content, the total flavonoid content, and the antioxidant capacity (diphenylpicrylhydrazyl, azinobisethylbenzothiazolinesulfonic acid, and ferric reducing antioxidant power: DPPH, ABTS, and FRAP respectively) were determined by standard methods. Significant differences were found at the individual and population levels in the contents of polyphenols, total flavonoids, antioxidant capacity, and specific alkaloids for leaves, bark, and wood. Farmed saplings grown under less light showed higher concentrations of higenamine, N-methylcoclaurine, N-methyllaurotetanine, and isocorydine, while those receiving more light were richer in laurolitsine, boldine, coclaurine, catechin, quercetin, epicatechin, quercitrin, and procyanidins. Important variations were found according to the season, age of the tree and of the leaves. The EO composition also varied considerably. These results support the idea that the natural variability of medicinal species is an important subject for study. |
Garrido, C; Clavijo, E; Copaja, S; Gomez-Jeria, J S; Campos-Vallette, M Vibrational and Electronic Spectroscopic Detection and Quantification of Carminic Acid in Candies Artículo de revista Food Chemistry, 283 , pp. 164-169, 2019, ISSN: 0308-8146. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN14l, title = {Vibrational and Electronic Spectroscopic Detection and Quantification of Carminic Acid in Candies}, author = {C Garrido and E Clavijo and S. Copaja and J.S. Gomez-Jeria and M Campos-Vallette}, url = {http://www.sciencedirect.com/science/article/pii/S0308814619300718}, doi = {https://doi.org/10.1016/j.foodchem.2018.12.123}, issn = {0308-8146}, year = {2019}, date = {2019-01-01}, journal = {Food Chemistry}, volume = {283}, pages = {164-169}, abstract = {Carminic acid (CA) contained in one kind of gummy candy was detected and quantified by using vibrational and electronic spectroscopy, respectively; the proposed methodology in solution is simple and rapid without sample pretreatment as usually used and reported. The identification of CA in candies was performed through the Raman and surface enhanced Raman scattering (SERS) spectra along with the equivalent spectral data from the natural CA dye. A modified silver colloidal solution was used in order to obtain SERS activity of CA at very low concentration in colloidal aqueous solution. Theoretical calculations allow infer about both the CA/silver surface interaction nature and on the orientation of CA on the surface. The electronic spectroscopic (UV\textendashVis) data allowed quantify CA in candies; the amount resulted nearly identical to that determined from HPLC traditional measurements. The present results should contribute to the health of children consumers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Carminic acid (CA) contained in one kind of gummy candy was detected and quantified by using vibrational and electronic spectroscopy, respectively; the proposed methodology in solution is simple and rapid without sample pretreatment as usually used and reported. The identification of CA in candies was performed through the Raman and surface enhanced Raman scattering (SERS) spectra along with the equivalent spectral data from the natural CA dye. A modified silver colloidal solution was used in order to obtain SERS activity of CA at very low concentration in colloidal aqueous solution. Theoretical calculations allow infer about both the CA/silver surface interaction nature and on the orientation of CA on the surface. The electronic spectroscopic (UV–Vis) data allowed quantify CA in candies; the amount resulted nearly identical to that determined from HPLC traditional measurements. The present results should contribute to the health of children consumers. |
Gallardo-Fuentes, S; Lezana, N; Lühr, S; Galdámez, A; Vilches-Herrera, M Influence of Non-Covalent Interactions in the Exo- and Regioselectivity of Aza-Diels–Alder Reactions: Experimental and Dft Calculations Artículo de revista The Journal of Organic Chemistry, 84 (17), pp. 10825-10831, 2019, ISSN: 0022-3263. @article{RN30l, title = {Influence of Non-Covalent Interactions in the Exo- and Regioselectivity of Aza-Diels\textendashAlder Reactions: Experimental and Dft Calculations}, author = {S. Gallardo-Fuentes and N. Lezana and S. L\"{u}hr and A. Gald\'{a}mez and M. Vilches-Herrera}, url = {https://doi.org/10.1021/acs.joc.9b01390}, doi = {10.1021/acs.joc.9b01390}, issn = {0022-3263}, year = {2019}, date = {2019-01-01}, journal = {The Journal of Organic Chemistry}, volume = {84}, number = {17}, pages = {10825-10831}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Diaz, C; Valenzuela, A M L; Soto, K; Laguna-Bercero, M A Incorporation of Au and Ag Nanostructures inside Sio2 Artículo de revista Journal of the Chilean Chemical Society, 64 (3), pp. 4502-4506, 2019. @article{RN25l, title = {Incorporation of Au and Ag Nanostructures inside Sio2}, author = {C. Diaz and A M L Valenzuela and K Soto and M A Laguna-Bercero}, url = {http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072019000304502&lng=en&nrm=iso&tlng=en}, doi = {10.4067/S0717-97072019000304502}, year = {2019}, date = {2019-01-01}, journal = {Journal of the Chilean Chemical Society}, volume = {64}, number = {3}, pages = {4502-4506}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Cortes, M D L A; Campa, De La R; Valenzuela, M L; Díaz, C; Carriedo, G A; Soto, Presa A Cylindrical Micelles by the Self-Assembly of Crystalline-B-Coil Polyphosphazene-B-P2vp Block Copolymers. Stabilization of Gold Nanoparticles Artículo de revista Molecules, 24 (9), pp. 1772-1772, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN26k, title = {Cylindrical Micelles by the Self-Assembly of Crystalline-B-Coil Polyphosphazene-B-P2vp Block Copolymers. Stabilization of Gold Nanoparticles}, author = {M D L A Cortes and R De La Campa and M L Valenzuela and C. D\'{i}az and G A Carriedo and A Presa Soto}, url = {https://www.mdpi.com/1420-3049/24/9/1772}, doi = {10.3390/molecules24091772}, year = {2019}, date = {2019-01-01}, journal = {Molecules}, volume = {24}, number = {9}, pages = {1772-1772}, abstract = { During the last number of years a variety of crystallization-driven self-assembly (CDSA) processes based on semicrystalline block copolymers have been developed to prepare a number of different nanomorphologies in solution (micelles). We herein present a convenient synthetic methodology combining: (i) The anionic polymerization of 2-vinylpyridine initiated by organolithium functionalized phosphane initiators; (ii) the cationic polymerization of iminophosphoranes initiated by \textendashPR2Cl2; and (iii) a macromolecular nucleophilic substitution step, to prepare the novel block copolymers poly(bistrifluoroethoxy phosphazene)-b-poly(2-vinylpyridine) (PTFEP-b-P2VP), having semicrystalline PTFEP core forming blocks. The self-assembly of these materials in mixtures of THF (tetrahydrofuran) and 2-propanol (selective solvent to P2VP), lead to a variety of cylindrical micelles of different lengths depending on the amount of 2-propanol added. We demonstrated that the crystallization of the PTFEP at the core of the micelles is the main factor controlling the self-assembly processes. The presence of pyridinyl moieties at the corona of the micelles was exploited to stabilize gold nanoparticles (AuNPs). },keywords = {}, pubstate = {published}, tppubtype = {article} } <p>During the last number of years a variety of crystallization-driven self-assembly (CDSA) processes based on semicrystalline block copolymers have been developed to prepare a number of different nanomorphologies in solution (micelles). We herein present a convenient synthetic methodology combining: (i) The anionic polymerization of 2-vinylpyridine initiated by organolithium functionalized phosphane initiators; (ii) the cationic polymerization of iminophosphoranes initiated by –PR2Cl2; and (iii) a macromolecular nucleophilic substitution step, to prepare the novel block copolymers poly(bistrifluoroethoxy phosphazene)-b-poly(2-vinylpyridine) (PTFEP-b-P2VP), having semicrystalline PTFEP core forming blocks. The self-assembly of these materials in mixtures of THF (tetrahydrofuran) and 2-propanol (selective solvent to P2VP), lead to a variety of cylindrical micelles of different lengths depending on the amount of 2-propanol added. We demonstrated that the crystallization of the PTFEP at the core of the micelles is the main factor controlling the self-assembly processes. The presence of pyridinyl moieties at the corona of the micelles was exploited to stabilize gold nanoparticles (AuNPs).</p> |
Cabañas-García, E; Areche, C; Jáuregui-Rincón, J; Cruz-Sosa, F; Balch, Pérez-Molphe E Phytochemical Profiling of Coryphantha Macromeris (Cactaceae) Growing in Greenhouse Conditions Using Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry Artículo de revista Molecules, 24 (4), pp. 705-705, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN5l, title = {Phytochemical Profiling of Coryphantha Macromeris (Cactaceae) Growing in Greenhouse Conditions Using Ultra-High-Performance Liquid Chromatography\textendashTandem Mass Spectrometry}, author = {E Caba\~{n}as-Garc\'{i}a and C. Areche and J J\'{a}uregui-Rinc\'{o}n and F Cruz-Sosa and E P\'{e}rez-Molphe Balch}, url = {http://www.mdpi.com/1420-3049/24/4/705}, doi = {10.3390/molecules24040705}, year = {2019}, date = {2019-01-01}, journal = {Molecules}, volume = {24}, number = {4}, pages = {705-705}, abstract = { Chromatographic separation combined with mass spectrometry is a powerful tool for the characterization of plant metabolites because of its high sensitivity and selectivity. In this work, the phytochemical profile of aerial and radicular parts of Coryphantha macromeris (Engelm.) Britton & Rose growing under greenhouse conditions was qualitatively investigated for the first time by means of modern ultra-high-performance liquid chromatography\textendashtandem mass spectrometry (UHPLC-PDA-HESI-Orbitrap-MS/MS). The UHPLC-PDA-HESI-Orbitrap-MS/MS analysis indicated a high complexity in phenolic metabolites. In our investigation, 69 compounds were detected and 60 of them were identified. Among detected compounds, several phenolic acids, phenolic glycosides, and organic acids were found. Within this diversity, 26 metabolites were exclusively detected in the aerial part, and 19 in the roots. Twenty-four metabolites occurred in both plant parts. According to the relative abundance of peaks in the chromatogram, ferulic and piscidic acids and their derivatives may correspond to one of the main phenolic compounds of C. macromeris. Our results contribute to the phytochemical knowledge regarding C. macromeris and its potential applications in the pharmaceutical and cosmetic industries. Besides, some metabolites and their fragmentation patterns are reported here for the first time for cacti species. },keywords = {}, pubstate = {published}, tppubtype = {article} } <p>Chromatographic separation combined with mass spectrometry is a powerful tool for the characterization of plant metabolites because of its high sensitivity and selectivity. In this work, the phytochemical profile of aerial and radicular parts of Coryphantha macromeris (Engelm.) Britton & Rose growing under greenhouse conditions was qualitatively investigated for the first time by means of modern ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-PDA-HESI-Orbitrap-MS/MS). The UHPLC-PDA-HESI-Orbitrap-MS/MS analysis indicated a high complexity in phenolic metabolites. In our investigation, 69 compounds were detected and 60 of them were identified. Among detected compounds, several phenolic acids, phenolic glycosides, and organic acids were found. Within this diversity, 26 metabolites were exclusively detected in the aerial part, and 19 in the roots. Twenty-four metabolites occurred in both plant parts. According to the relative abundance of peaks in the chromatogram, ferulic and piscidic acids and their derivatives may correspond to one of the main phenolic compounds of C. macromeris. Our results contribute to the phytochemical knowledge regarding C. macromeris and its potential applications in the pharmaceutical and cosmetic industries. Besides, some metabolites and their fragmentation patterns are reported here for the first time for cacti species.</p> |
Areche, C; Zapata, F; González, M; Díaz, E; Montecinos, R; Hernández, M; Melo, F; Cornejo, A Anthraquinone Derivative Reduces Tau Oligomer Progression by Inhibiting Cysteine-Cysteine Interaction Artículo de revista ChemistryOpen, 8 (5), pp. 554-559, 2019, ISSN: 2191-1363. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN1_119, title = {Anthraquinone Derivative Reduces Tau Oligomer Progression by Inhibiting Cysteine-Cysteine Interaction}, author = {C. Areche and F Zapata and M Gonz\'{a}lez and E D\'{i}az and R Montecinos and M Hern\'{a}ndez and F Melo and A Cornejo}, url = {https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/open.201800222}, doi = {10.1002/open.201800222}, issn = {2191-1363}, year = {2019}, date = {2019-01-01}, journal = {ChemistryOpen}, volume = {8}, number = {5}, pages = {554-559}, abstract = {Abstract Tau protein is a natively unfolded protein whose primary role is to participate in axonal transport closely associated with microtubules. Neurodegenerative disorders including Alzheimer's disease and Tauopathies involved tau protein that is found hyperphosphorylated in vivo; then, tau is detached from microtubules to form toxic aggregates or oligomers, which have a deleterious effect on membranes, triggering an inflammatory response. Considering finding tau inhibitors, we isolated two compounds in the ethyl acetate extract from Xanthoria ectaneoides (Nyl.) Zahlbr; ergosterol peroxide (1) and a new anthraquinone (2). We established the structure through spectroscopic data and biogenic considerations, and we named it “2-hydroxy-3-((8-hydroxy-3-methoxy-6-methylanthraquinonyl)oxy)propanoic acid”. This new anthraquinone was evaluated as a tau inhibitor by ThT fluorescence, dot blot assays and total internal reflection fluorescence microscopy. Our results strongly suggest that this anthraquinone remodels soluble oligomers and diminishes β-sheet content. Moreover, through the fluorescence labeling of cysteine inside of the microtubule-binding domain (4R), we showed that this anthraquinone could reduce the oligomers progression by inhibiting cysteine interactions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Abstract Tau protein is a natively unfolded protein whose primary role is to participate in axonal transport closely associated with microtubules. Neurodegenerative disorders including Alzheimer's disease and Tauopathies involved tau protein that is found hyperphosphorylated in vivo; then, tau is detached from microtubules to form toxic aggregates or oligomers, which have a deleterious effect on membranes, triggering an inflammatory response. Considering finding tau inhibitors, we isolated two compounds in the ethyl acetate extract from Xanthoria ectaneoides (Nyl.) Zahlbr; ergosterol peroxide (1) and a new anthraquinone (2). We established the structure through spectroscopic data and biogenic considerations, and we named it “2-hydroxy-3-((8-hydroxy-3-methoxy-6-methylanthraquinonyl)oxy)propanoic acid”. This new anthraquinone was evaluated as a tau inhibitor by ThT fluorescence, dot blot assays and total internal reflection fluorescence microscopy. Our results strongly suggest that this anthraquinone remodels soluble oligomers and diminishes β-sheet content. Moreover, through the fluorescence labeling of cysteine inside of the microtubule-binding domain (4R), we showed that this anthraquinone could reduce the oligomers progression by inhibiting cysteine interactions. |
Areche, C; Fernandez-Burgos, R; Terrones, De T C; Simirgiotis, M; García-Beltrán, O; Borquez, J; Sepulveda, B Mulinum Crassifolium Phil; Two New Mulinanes, Gastroprotective Activity and Metabolomic Analysis by Uhplc-Orbitrap Mass Spectrometry Artículo de revista Molecules, 24 (9), pp. 1673-1673, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN4_35, title = {Mulinum Crassifolium Phil; Two New Mulinanes, Gastroprotective Activity and Metabolomic Analysis by Uhplc-Orbitrap Mass Spectrometry}, author = {C. Areche and R Fernandez-Burgos and T C De Terrones and M Simirgiotis and O Garc\'{i}a-Beltr\'{a}n and J Borquez and B Sepulveda}, url = {https://www.mdpi.com/1420-3049/24/9/1673}, doi = {10.3390/molecules24091673}, year = {2019}, date = {2019-01-01}, journal = {Molecules}, volume = {24}, number = {9}, pages = {1673-1673}, abstract = { Mulinum crassifolium Phil. (Apiaceae) is an endemic shrub from Chile commonly used as infusion in traditional medicine to treat diabetes, bronchial and intestinal disorders and stomach ailments, including ulcers. From the EtOAc extract of this plant, the new mulinane-type diterpenoids 3 and 5 were isolated along with three known diterpenoids. The gastroprotective effect of the infusion of the plant was assayed to support the traditional use and a fast HPLC analysis using high resolution techniques was performed to identify the bioactive constituents. The EtOAc extract and the edible infusion showed gastroprotective effect at 100 mg/kg in the HCl/EtOH induced gastric ulcer model in mice, reducing lesions by 33% and 74%, respectively. Finally, a metabolomic profiling based on UHPLC-ESI-MS/HRMS of the edible infusion was performed and thirty-five compounds were tentatively identified including quercetin, caffeic acid, apigenine glucoside, p-coumaric acid, chlorogenic acids, and caffeoylquinic acids, which have been associated previously with gastroprotective and antiulcer properties. This scientific evidence can support the contribution of polyphenols in the gastroprotective activity of the edible infusion of this plant, and can validate at least in part, its ethnopharmacological use. },keywords = {}, pubstate = {published}, tppubtype = {article} } <p>Mulinum crassifolium Phil. (Apiaceae) is an endemic shrub from Chile commonly used as infusion in traditional medicine to treat diabetes, bronchial and intestinal disorders and stomach ailments, including ulcers. From the EtOAc extract of this plant, the new mulinane-type diterpenoids 3 and 5 were isolated along with three known diterpenoids. The gastroprotective effect of the infusion of the plant was assayed to support the traditional use and a fast HPLC analysis using high resolution techniques was performed to identify the bioactive constituents. The EtOAc extract and the edible infusion showed gastroprotective effect at 100 mg/kg in the HCl/EtOH induced gastric ulcer model in mice, reducing lesions by 33% and 74%, respectively. Finally, a metabolomic profiling based on UHPLC-ESI-MS/HRMS of the edible infusion was performed and thirty-five compounds were tentatively identified including quercetin, caffeic acid, apigenine glucoside, p-coumaric acid, chlorogenic acids, and caffeoylquinic acids, which have been associated previously with gastroprotective and antiulcer properties. This scientific evidence can support the contribution of polyphenols in the gastroprotective activity of the edible infusion of this plant, and can validate at least in part, its ethnopharmacological use.</p> |
Allende, P; Barrientos, L; Orera, A; Laguna-Bercero, M A; Salazar, N; Valenzuela, M L; Diaz, C Tio2/Sio2 Composite for Efficient Protection of Uva and Uvb Rays through of a Solvent-Less Synthesis Artículo de revista Journal of Cluster Science, 30 (6), pp. 1511-1517, 2019, ISSN: 1572-8862. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN24i, title = {Tio2/Sio2 Composite for Efficient Protection of Uva and Uvb Rays through of a Solvent-Less Synthesis}, author = {P Allende and L Barrientos and A Orera and M A Laguna-Bercero and N Salazar and M L Valenzuela and C. Diaz}, url = {https://doi.org/10.1007/s10876-019-01594-9}, doi = {10.1007/s10876-019-01594-9}, issn = {1572-8862}, year = {2019}, date = {2019-01-01}, journal = {Journal of Cluster Science}, volume = {30}, number = {6}, pages = {1511-1517}, abstract = {In an effort to discover new inorganic UV absorbers, titania included into silica was prepared using a solvent-less solid state method involving the pyrolysis of the as prepared precursor Chitosan·(TiOSO4)/SiO2, as an alternative and versatile way to using these compounds for practical applications. The new TiO2/SiO2 composite was characterized by PXRD, SEM\textendashEDS, TEM and UV\textendashVis absorption analysis. The SEM\textendashEDS mapping images show a uniform distribution of TiO2 into the silica matrix. The optical properties of the composite have shown an interesting result related to high absorption of UVB rays and an improved absorption of UVA rays than pure TiO2. Efficient suppression of photocatalytic behavior of TiO2, when is incorporated into silica, was evidenced from 85 to 31%, suggesting it material as alternative inorganic UV absorber to remains the properties of the methylene blue dye. These results reveal their potential use in practical textile industry and UV protection agent to avoid human damage.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In an effort to discover new inorganic UV absorbers, titania included into silica was prepared using a solvent-less solid state method involving the pyrolysis of the as prepared precursor Chitosan·(TiOSO4)/SiO2, as an alternative and versatile way to using these compounds for practical applications. The new TiO2/SiO2 composite was characterized by PXRD, SEM–EDS, TEM and UV–Vis absorption analysis. The SEM–EDS mapping images show a uniform distribution of TiO2 into the silica matrix. The optical properties of the composite have shown an interesting result related to high absorption of UVB rays and an improved absorption of UVA rays than pure TiO2. Efficient suppression of photocatalytic behavior of TiO2, when is incorporated into silica, was evidenced from 85 to 31%, suggesting it material as alternative inorganic UV absorber to remains the properties of the methylene blue dye. These results reveal their potential use in practical textile industry and UV protection agent to avoid human damage. |
Aliaga, J; Vera, P; Araya, J; Ballesteros, L; Urzúa, J; Farías, M; Paraguay-Delgado, F; Alonso-Núñez, G; González, G; Benavente, E Electrochemical Hydrogen Evolution over Hydrothermally Synthesized Re-Doped Mos2 Flower-Like Microspheres Artículo de revista Molecules, 24 (24), pp. 4631-4631, 2019. Resumen | Enlaces | BibTeX | Etiquetas: Electrochemical Hydrogen Evolution, Hydrothermally, Microspheres @article{RN52, title = {Electrochemical Hydrogen Evolution over Hydrothermally Synthesized Re-Doped Mos2 Flower-Like Microspheres}, author = {J Aliaga and P Vera and J Araya and L Ballesteros and J Urz\'{u}a and M Far\'{i}as and F Paraguay-Delgado and G Alonso-N\'{u}\~{n}ez and G. Gonz\'{a}lez and E Benavente}, url = {https://www.mdpi.com/1420-3049/24/24/4631}, doi = {10.3390/molecules24244631}, year = {2019}, date = {2019-01-01}, journal = {Molecules}, volume = {24}, number = {24}, pages = {4631-4631}, abstract = { In this research, we report a simple hydrothermal synthesis to prepare rhenium (Re)- doped MoS2 flower-like microspheres and the tuning of their structural, electronic, and electrocatalytic properties by modulating the insertion of Re. The obtained compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Structural, morphological, and chemical analyses confirmed the synthesis of poorly crystalline Re-doped MoS2 flower-like microspheres composed of few stacked layers. They exhibit enhanced hydrogen evolution reaction (HER) performance with low overpotential of 210 mV at current density of 10 mA/cm2, with a small Tafel slope of 78 mV/dec. The enhanced catalytic HER performance can be ascribed to activation of MoS2 basal planes and by reduction in charge transfer resistance during HER upon doping. },keywords = {Electrochemical Hydrogen Evolution, Hydrothermally, Microspheres}, pubstate = {published}, tppubtype = {article} } <p>In this research, we report a simple hydrothermal synthesis to prepare rhenium (Re)- doped MoS2 flower-like microspheres and the tuning of their structural, electronic, and electrocatalytic properties by modulating the insertion of Re. The obtained compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Structural, morphological, and chemical analyses confirmed the synthesis of poorly crystalline Re-doped MoS2 flower-like microspheres composed of few stacked layers. They exhibit enhanced hydrogen evolution reaction (HER) performance with low overpotential of 210 mV at current density of 10 mA/cm2, with a small Tafel slope of 78 mV/dec. The enhanced catalytic HER performance can be ascribed to activation of MoS2 basal planes and by reduction in charge transfer resistance during HER upon doping.</p> |
Toro, R; Kvakić, M; Klaić, Z B; Koračin, D; Morales, R G E; Leiva, M A Exploring atmospheric stagnation during a severe particulate matter air pollution episode over complex terrain in Santiago, Chile Artículo de revista Environmental Pollution, 244 , pp. 705 - 714, 2019, ISSN: 0269-7491. @article{TOROA2019705, title = {Exploring atmospheric stagnation during a severe particulate matter air pollution episode over complex terrain in Santiago, Chile}, author = {R. Toro and M. Kvaki\'{c} and Z. B Klai\'{c} and D. Kora\v{c}in and R.G.E. Morales and M.A. Leiva}, url = {http://www.sciencedirect.com/science/article/pii/S0269749118311461}, doi = {https://doi.org/10.1016/j.envpol.2018.10.067}, issn = {0269-7491}, year = {2019}, date = {2019-01-01}, journal = {Environmental Pollution}, volume = {244}, pages = {705 - 714}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Gomez-Jeria, J S; Gutierrez, S; Pizarro, G A preliminary FTIR-ATRand XRFanalyses of the cellulose of four postcards from the Reichskommissariat Ostland and theGerman occupations of Pleskau (Russia) and Latvia Artículo de revista Chemistry Research Journal, 4 , pp. 48-57, 2019, ISSN: 2455-8990. Resumen | Enlaces | BibTeX | Etiquetas: cellulose, FTIR-ATR, German occupation of Latvia, German occupation of Russia, infrared spectroscopy, Latvia, philately, Pleskau, Postcards, raman, Reichskommissariat Ostland, Russia, Third Reich, X-Ray fluorescence, xrf @article{RN1014, title = {A preliminary FTIR-ATRand XRFanalyses of the cellulose of four postcards from the Reichskommissariat Ostland and theGerman occupations of Pleskau (Russia) and Latvia}, author = {J.S. Gomez-Jeria and S. Gutierrez and G. Pizarro}, url = {http://chemrj.org/download/vol-4-iss-3-2019/chemrj-2019-04-03-48-57.pdf}, issn = {2455-8990}, year = {2019}, date = {2019-01-01}, journal = {Chemistry Research Journal}, volume = {4}, pages = {48-57}, publisher = {Leon Publications}, abstract = {FTIR-ATR and XRF techniques have been employed to carry out a preliminary characterization of the cellulose of four postcards issued during the Third Reich war in the East. Two postcards were printed in Berlin while the other two corresponded to communist Russian postcards with German overprints. The XRF results show that only the paper of the German postcards contains potassium. The four postcards present Fe and Cu that could oxidize cellulose. The possible presence of cotton is suggested but not proved.}, keywords = {cellulose, FTIR-ATR, German occupation of Latvia, German occupation of Russia, infrared spectroscopy, Latvia, philately, Pleskau, Postcards, raman, Reichskommissariat Ostland, Russia, Third Reich, X-Ray fluorescence, xrf}, pubstate = {published}, tppubtype = {article} } FTIR-ATR and XRF techniques have been employed to carry out a preliminary characterization of the cellulose of four postcards issued during the Third Reich war in the East. Two postcards were printed in Berlin while the other two corresponded to communist Russian postcards with German overprints. The XRF results show that only the paper of the German postcards contains potassium. The four postcards present Fe and Cu that could oxidize cellulose. The possible presence of cotton is suggested but not proved. |
Gomez-Jeria, J S; Gatica-Diaz, N A preliminary quantum chemical analysis of the relationships between electronic structure and 5-HT1A and 5-HT2A receptor affinity in a series of 8-acetyl-7-hydroxy-4-methylcoumarin derivatives Artículo de revista Chemistry Research Journal, 4 , pp. 85-100, 2019, ISSN: 2455-8990. Resumen | BibTeX | Etiquetas: 5-HT1A receptor, 5-HT2A receptor, density functional theory, dft, KPG method, methylcoumarin, qsar, serotonin @article{RN1013, title = {A preliminary quantum chemical analysis of the relationships between electronic structure and 5-HT1A and 5-HT2A receptor affinity in a series of 8-acetyl-7-hydroxy-4-methylcoumarin derivatives}, author = {J.S. Gomez-Jeria and N. Gatica-Diaz}, issn = {2455-8990}, year = {2019}, date = {2019-01-01}, journal = {Chemistry Research Journal}, volume = {4}, pages = {85-100}, publisher = {Leon Publications}, abstract = {We present the results of a quantum-chemical analysis of the relationships between electronic structure and 5-HT1A and 5-HT2A receptor binding affinity for a series of 8-acetyl-7-hydroxy-4-methylcoumarin derivatives. The KPG model coupled with DFT calculations at the 6-31G(d,p) level were employed. Two statistically significant results were obtained. The results are synthesized in the corresponding partial pharmacophores. The most important result suggests that an unsaturated ring is an almost sure target for the development of new compounds with affinity for both receptors.}, keywords = {5-HT1A receptor, 5-HT2A receptor, density functional theory, dft, KPG method, methylcoumarin, qsar, serotonin}, pubstate = {published}, tppubtype = {article} } We present the results of a quantum-chemical analysis of the relationships between electronic structure and 5-HT1A and 5-HT2A receptor binding affinity for a series of 8-acetyl-7-hydroxy-4-methylcoumarin derivatives. The KPG model coupled with DFT calculations at the 6-31G(d,p) level were employed. Two statistically significant results were obtained. The results are synthesized in the corresponding partial pharmacophores. The most important result suggests that an unsaturated ring is an almost sure target for the development of new compounds with affinity for both receptors. |
Gomez-Jeria, J S; Garrido-Saez, N A DFT analysis of the relationships between electronic structure and affinity for dopamine D2, D3 and D4 receptor subtypesin a group of 77-LH-28-1 derivatives Artículo de revista Chemistry Research Journal,, 4 , pp. 30-42, 2019, ISSN: 2455-8990. Resumen | BibTeX | Etiquetas: 77-LH-28-1, D2 receptor, D3 receptor, D4 receptor, dft, dopamine, electronic structure, KPG method, qsar, receptor affinity @article{RN10012, title = {A DFT analysis of the relationships between electronic structure and affinity for dopamine D2, D3 and D4 receptor subtypesin a group of 77-LH-28-1 derivatives}, author = {J.S. Gomez-Jeria and N. Garrido-Saez}, issn = {2455-8990}, year = {2019}, date = {2019-01-01}, journal = {Chemistry Research Journal,}, volume = {4}, pages = {30-42}, publisher = {Leon Publications}, abstract = {We have studied the relationships between electronic structure and affinity for D2, D3 and D4 dopamine receptor subtypesin a group of 1-[3-(4-butylpiperidin-1-yl)propyl]-1,2,3,4-tetrahydroquinolin-2-one (77-LH-28-1) derivatives. The Klopman-Peradejordi-Gomez method was employed. Statistically significant results were obtained for all the cases. The analysis of the resulting equations provided data that can be used to design new derivatives with enhanced affinity through appropriate substitutions at selected atoms.}, keywords = {77-LH-28-1, D2 receptor, D3 receptor, D4 receptor, dft, dopamine, electronic structure, KPG method, qsar, receptor affinity}, pubstate = {published}, tppubtype = {article} } We have studied the relationships between electronic structure and affinity for D2, D3 and D4 dopamine receptor subtypesin a group of 1-[3-(4-butylpiperidin-1-yl)propyl]-1,2,3,4-tetrahydroquinolin-2-one (77-LH-28-1) derivatives. The Klopman-Peradejordi-Gomez method was employed. Statistically significant results were obtained for all the cases. The analysis of the resulting equations provided data that can be used to design new derivatives with enhanced affinity through appropriate substitutions at selected atoms. |
Gautier, K S; Kpotin, G A; Mensah, J -B; Gomez-Jeria, J S Quantum-Chemical Study of the Relationships between Electronic Structure and the Affinity of Benzisothiazolylpiperazine Derivatives for the Dopamine Hd2l and Hd3 Receptors Artículo de revista The Pharmaceutical and Chemical Journal, 6 , pp. 73-90, 2019, ISSN: 2349-7092. Resumen | Enlaces | BibTeX | Etiquetas: dft, hD2L receptor, hD3 receptor, KPG method, qsar, Schizophrenia @article{RN1011, title = {Quantum-Chemical Study of the Relationships between Electronic Structure and the Affinity of Benzisothiazolylpiperazine Derivatives for the Dopamine Hd2l and Hd3 Receptors}, author = {K.S. Gautier and G.A. Kpotin and J.-B. Mensah and J.S. Gomez-Jeria}, url = {http://tpcj.org/download/vol-6-iss-5-2019/TPCJ2019-06-05-73-90.pdf}, issn = {2349-7092}, year = {2019}, date = {2019-01-01}, journal = {The Pharmaceutical and Chemical Journal}, volume = {6}, pages = {73-90}, abstract = {Schizophrenia is a mental illness that induces a cognitive deficit, affects a large part of the world's population, and in particular Africa where it is ignored. To treat this disease, the antipsychotic derivatives of benzisothiazolylpiperazine (N-(trans-4-(2-(4-(benzo [d] isothiazol-3-yl) piperazin-1-yl) ethyl)cyclohexyl) amides) are employed because of their inhibitory powerfor the dopamine HD2L and HD3 receptors. The present study aims to establishrelationships between the electronic structure and the antipsychotic activity of benzisothiazolylpiperazine derivatives andto generate a 2D pharmacophore for predicting the antipsychotic activity of these derivatives. The KPG technique was employed. The electronic structure of all the molecules was calculatedat the DFT/B3LYP/6-31G (d,p) level of theory. We obtained two statistically significant equationsfor predicting the inhibition constant.The process seems to be charge and orbital controlled for receptor HD2L and orbital controlled for HD3. The two prediction equations obtained can be useful for proposing new derivatives with antipsychotic activity having an affinity with the dopamineHD2L and HD3 receptors.The two pharmacophores derived from these prediction models would be very useful for proposing newmolecules with potent antipsychotic activity.}, keywords = {dft, hD2L receptor, hD3 receptor, KPG method, qsar, Schizophrenia}, pubstate = {published}, tppubtype = {article} } Schizophrenia is a mental illness that induces a cognitive deficit, affects a large part of the world's population, and in particular Africa where it is ignored. To treat this disease, the antipsychotic derivatives of benzisothiazolylpiperazine (N-(trans-4-(2-(4-(benzo [d] isothiazol-3-yl) piperazin-1-yl) ethyl)cyclohexyl) amides) are employed because of their inhibitory powerfor the dopamine HD2L and HD3 receptors. The present study aims to establishrelationships between the electronic structure and the antipsychotic activity of benzisothiazolylpiperazine derivatives andto generate a 2D pharmacophore for predicting the antipsychotic activity of these derivatives. The KPG technique was employed. The electronic structure of all the molecules was calculatedat the DFT/B3LYP/6-31G (d,p) level of theory. We obtained two statistically significant equationsfor predicting the inhibition constant.The process seems to be charge and orbital controlled for receptor HD2L and orbital controlled for HD3. The two prediction equations obtained can be useful for proposing new derivatives with antipsychotic activity having an affinity with the dopamineHD2L and HD3 receptors.The two pharmacophores derived from these prediction models would be very useful for proposing newmolecules with potent antipsychotic activity. |
Gomez-Jeria, J S Biology and Philosophy V. Intermission. Goethe as an Appetizer Artículo de revista World Journal of Research and Review (WJRR), 8 (1), pp. 1-6, 2019, ISSN: 2455-3956. Resumen | Enlaces | BibTeX | Etiquetas: biology, chimpanzees, Faust, Genetics, Goethe, human evolution, language, Mephistopheles. @article{RN1004, title = {Biology and Philosophy V. Intermission. Goethe as an Appetizer}, author = {J.S. Gomez-Jeria}, url = {https://www.researchgate.net/publication/331413000_Biology_and_Philosophy_V_Intermission_Goethe_as_an_Appetizer}, doi = {https://doi.org/10.31871/WJRR.8.3.24}, issn = {2455-3956}, year = {2019}, date = {2019-01-01}, journal = {World Journal of Research and Review (WJRR)}, volume = {8}, number = {1}, pages = {1-6}, publisher = {Nextgen Research Publication}, abstract = {I comment on my proposition that certain parts of Faust I relate fragments of Goethe\'{i}s internal search. First I comment about language as a tool for group exchange of information. Inner speech (thinking with words) is a new and a potent tool to develop an inner personal world whose wealth and complexity are related to the number of words that the individual handles. Some people expose part or all of their inner worlds through books, theater plays, speeches, etc. Internal and external languages serve to formulate what I consider a fundamental question: During my life have I done anything different from what a chimpanzee does? Goethe was a prolific writer but he had never before written about philosophy. Examining Faust I you find clear signs of internal dissatisfaction coupled with a lack of ability to climb to the higher echelons of the human mode. This failure is confessed when Faust makes an arrangement with Mephistopheles and seduces a teenage girl. Faust returns to one of the main biological impulses, and a strong one: sex. Faust/Goethe is totally dominated by the soul that grips the earth with all its senses, as he says. No philosophy is possible now.}, keywords = {biology, chimpanzees, Faust, Genetics, Goethe, human evolution, language, Mephistopheles.}, pubstate = {published}, tppubtype = {article} } I comment on my proposition that certain parts of Faust I relate fragments of Goetheís internal search. First I comment about language as a tool for group exchange of information. Inner speech (thinking with words) is a new and a potent tool to develop an inner personal world whose wealth and complexity are related to the number of words that the individual handles. Some people expose part or all of their inner worlds through books, theater plays, speeches, etc. Internal and external languages serve to formulate what I consider a fundamental question: During my life have I done anything different from what a chimpanzee does? Goethe was a prolific writer but he had never before written about philosophy. Examining Faust I you find clear signs of internal dissatisfaction coupled with a lack of ability to climb to the higher echelons of the human mode. This failure is confessed when Faust makes an arrangement with Mephistopheles and seduces a teenage girl. Faust returns to one of the main biological impulses, and a strong one: sex. Faust/Goethe is totally dominated by the soul that grips the earth with all its senses, as he says. No philosophy is possible now. |
Gomez-Jeria, J S; Sanchez-Jara, B Chemistry Research Journal, 4 , pp. 46-59, 2019, ISSN: 2455-8990. Resumen | Enlaces | BibTeX | Etiquetas: adenosine receptors, common skeleton, dft, electronic structure, KPG method, pharmacophore, purine, purine derivatives, qsar, receptor affinity @article{RN1001, title = {An introductory theoretical investigation of the relationships between electronic structure and A1, A2A and A3 adenosine receptor affinities of a series of N6-8,9-trisubstituted purine derivatives}, author = {J.S. Gomez-Jeria and B. Sanchez-Jara}, url = {https://www.researchgate.net/publication/330521580_An_introductory_theoretical_analysis_of_the_relationships_between_electronic_structure_and_A1_A2A_and_A3_adenosine_receptor_affinities_of_a_series_of_N6-89-trisubstituted_purine_derivatives}, issn = {2455-8990}, year = {2019}, date = {2019-01-01}, journal = {Chemistry Research Journal}, volume = {4}, pages = {46-59}, publisher = {Leon Publications}, abstract = {A study of the relationships between receptor affinity and electronic structure was performed in a group of N6-8,9-trisubstituted purine derivatives interacting with A1, A2A and A3 adenosine receptors. Statistically significant equations were obtained for all cases.}, keywords = {adenosine receptors, common skeleton, dft, electronic structure, KPG method, pharmacophore, purine, purine derivatives, qsar, receptor affinity}, pubstate = {published}, tppubtype = {article} } A study of the relationships between receptor affinity and electronic structure was performed in a group of N6-8,9-trisubstituted purine derivatives interacting with A1, A2A and A3 adenosine receptors. Statistically significant equations were obtained for all cases. |
Cossio-Rodriguez, R; Cocroft, R B; Niemeyer, H M; Pinto, C F Mate Searching in Ennya Maculicornis (Membracidae: Polyglyptini) Initiated by Females: Behavioural and Acoustic Descriptions Artículo de revista Ecological Entomology, 44 (3), pp. 406-412, 2019, ISSN: 0307-6946. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN77, title = {Mate Searching in Ennya Maculicornis (Membracidae: Polyglyptini) Initiated by Females: Behavioural and Acoustic Descriptions}, author = {R Cossio-Rodriguez and R B Cocroft and H.M. Niemeyer and C F Pinto}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/een.12718}, doi = {10.1111/een.12718}, issn = {0307-6946}, year = {2019}, date = {2019-01-01}, journal = {Ecological Entomology}, volume = {44}, number = {3}, pages = {406-412}, abstract = {1. In treehoppers in which courtship has been studied, males initiate the search for females by periodically emitting a vibrational signal. The responses by the female are used by males as a beacon and give rise to a duet. 2. Courtship and mating of the treehopper Ennya maculicornis were characterised through the simultaneous recording of vibrational signals and the behaviour of males and females in an arena. 3. In E. maculicornis, female initiated mate searching. Females produced two types of signals during the this process: (i) a signal that preceded the approach by the male and (ii) a signal that preceded mating. Males emitted two signals associated with two stereotyped body movements: (i) a signal produced as a response to the first signal emitted by the female, involving a change in the male's locomotory mode and the approach to the female, and (ii) a signal produced after finding and holding on to the female, involving simultaneous abdomen raising and wing fluttering. These signals were repeated several times before the female emitted the second signal. The four signalling patterns were observed in all recordings in which mating was observed. When any of the signals was missing, mating did not occur. 4. Female-biased sex ratios in E. maculicornis, along with iteroparity, are suggested to explain the initiation of mate searching behaviour by females. A comparison of data with that from other treehoppers indicates that vibrational signals and their associated behaviour are more diverse among treehoppers than has been appreciated previously.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 1. In treehoppers in which courtship has been studied, males initiate the search for females by periodically emitting a vibrational signal. The responses by the female are used by males as a beacon and give rise to a duet. 2. Courtship and mating of the treehopper Ennya maculicornis were characterised through the simultaneous recording of vibrational signals and the behaviour of males and females in an arena. 3. In E. maculicornis, female initiated mate searching. Females produced two types of signals during the this process: (i) a signal that preceded the approach by the male and (ii) a signal that preceded mating. Males emitted two signals associated with two stereotyped body movements: (i) a signal produced as a response to the first signal emitted by the female, involving a change in the male's locomotory mode and the approach to the female, and (ii) a signal produced after finding and holding on to the female, involving simultaneous abdomen raising and wing fluttering. These signals were repeated several times before the female emitted the second signal. The four signalling patterns were observed in all recordings in which mating was observed. When any of the signals was missing, mating did not occur. 4. Female-biased sex ratios in E. maculicornis, along with iteroparity, are suggested to explain the initiation of mate searching behaviour by females. A comparison of data with that from other treehoppers indicates that vibrational signals and their associated behaviour are more diverse among treehoppers than has been appreciated previously. |
Ribba, L; Tamayo, L; Flores, M; Riveros, A; Kogan, M J; Cerda, E; Goyanes, S Asymmetric Biphasic Hydrophobic/Hydrophilic Poly(Lactic Acid)–Polyvinyl Alcohol Meshes with Moisture Control and Noncytotoxic Effects for Wound Dressing Applications Artículo de revista Journal of Applied Polymer Science, 136 (17), pp. 47369, 2019, ISSN: 0021-8995. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN69, title = {Asymmetric Biphasic Hydrophobic/Hydrophilic Poly(Lactic Acid)\textendashPolyvinyl Alcohol Meshes with Moisture Control and Noncytotoxic Effects for Wound Dressing Applications}, author = {L Ribba and L. Tamayo and M Flores and A Riveros and M J Kogan and E Cerda and S Goyanes}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/app.47369}, doi = {10.1002/app.47369}, issn = {0021-8995}, year = {2019}, date = {2019-01-01}, journal = {Journal of Applied Polymer Science}, volume = {136}, number = {17}, pages = {47369}, publisher = {2012 Elsevier B.V.}, abstract = {ABSTRACT A noncytotoxic film was developed in this work with asymmetric biphasic properties (hydrophilic/hydrophobic) that allow for gas exchange. Among its many biomedical applications, it could be applied as a wound dressing material where the absorption of exuded fluids and control of water loss is required simultaneously. Thin meshes were developed modifying one face of poly(lactic acid) (PLA) electrospun mats with polyvinyl alcohol (PVA) using a simple photografting methodology. The contact angle of the modified face of the film was 44° while that of the other face was the original value of 122°. The chemical modification was covalent, as confirmed by X-ray photoelectron spectroscopy, stable over time and resistant to successive washing steps. Cytotoxic assays with fibroblast cells showed that PVA photo-grafted onto PLA meshes present a high cell viability percentage. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47369.}, keywords = {}, pubstate = {published}, tppubtype = {article} } ABSTRACT A noncytotoxic film was developed in this work with asymmetric biphasic properties (hydrophilic/hydrophobic) that allow for gas exchange. Among its many biomedical applications, it could be applied as a wound dressing material where the absorption of exuded fluids and control of water loss is required simultaneously. Thin meshes were developed modifying one face of poly(lactic acid) (PLA) electrospun mats with polyvinyl alcohol (PVA) using a simple photografting methodology. The contact angle of the modified face of the film was 44° while that of the other face was the original value of 122°. The chemical modification was covalent, as confirmed by X-ray photoelectron spectroscopy, stable over time and resistant to successive washing steps. Cytotoxic assays with fibroblast cells showed that PVA photo-grafted onto PLA meshes present a high cell viability percentage. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47369. |
Pinto, C F; Torrico-Bazoberry, D; Penna, M; Cossio-Rodríguez, R; Cocroft, R; Appel, H; Niemeyer, H M Chemical Responses of Nicotiana Tabacum (Solanaceae) Induced by Vibrational Signals of a Generalist Herbivore Artículo de revista Journal of Chemical Ecology, 45 (8), pp. 708-714, 2019, ISSN: 1573-1561. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN76, title = {Chemical Responses of Nicotiana Tabacum (Solanaceae) Induced by Vibrational Signals of a Generalist Herbivore}, author = {C F Pinto and D Torrico-Bazoberry and M Penna and R Cossio-Rodr\'{i}guez and R Cocroft and H Appel and H.M. Niemeyer}, url = {https://doi.org/10.1007/s10886-019-01089-x}, doi = {10.1007/s10886-019-01089-x}, issn = {1573-1561}, year = {2019}, date = {2019-01-01}, journal = {Journal of Chemical Ecology}, volume = {45}, number = {8}, pages = {708-714}, publisher = {2012 Elsevier Inc.}, abstract = {Plants are able to sense their environment and respond appropriately to different stimuli. Vibrational signals (VS) are one of the most widespread yet understudied ways of communication between organisms. Recent research into the perception of VS by plants showed that they are ecologically meaningful signals involved in different interactions of plants with biotic and abiotic agents. We studied changes in the concentration of alkaloids in tobacco plants induced by VS produced by Phthorimaea operculella (Lepidoptera: Gelechiidae), a generalist caterpillar that naturally feeds on the plant. We measured the concentration of nicotine, nornicotine, anabasine and anatabine in four treatments applied to 11-weeks old tobacco plant: a) Co = undamaged plants, b) Eq = Playback equipment attached to the plant without VS, c) Ca = Plants attacked by P. operculella herbivory and d) Pl = playback of VS of P. operculella feeding on tobacco. We found that nicotine, the most abundant alkaloid, increased more than 2.6 times in the Ca and Pl treatments as compared with the Co and Eq treatments, which were similar between them. Nornicotine, anabasine and anatabine were mutually correlated and showed similar concentration patterns, being higher in the Eq treatment. Results are discussed in terms of the adaptive significance of plant responses to ecologically important VS stimuli.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Plants are able to sense their environment and respond appropriately to different stimuli. Vibrational signals (VS) are one of the most widespread yet understudied ways of communication between organisms. Recent research into the perception of VS by plants showed that they are ecologically meaningful signals involved in different interactions of plants with biotic and abiotic agents. We studied changes in the concentration of alkaloids in tobacco plants induced by VS produced by Phthorimaea operculella (Lepidoptera: Gelechiidae), a generalist caterpillar that naturally feeds on the plant. We measured the concentration of nicotine, nornicotine, anabasine and anatabine in four treatments applied to 11-weeks old tobacco plant: a) Co = undamaged plants, b) Eq = Playback equipment attached to the plant without VS, c) Ca = Plants attacked by P. operculella herbivory and d) Pl = playback of VS of P. operculella feeding on tobacco. We found that nicotine, the most abundant alkaloid, increased more than 2.6 times in the Ca and Pl treatments as compared with the Co and Eq treatments, which were similar between them. Nornicotine, anabasine and anatabine were mutually correlated and showed similar concentration patterns, being higher in the Eq treatment. Results are discussed in terms of the adaptive significance of plant responses to ecologically important VS stimuli. |
Benavente, E; Aliaga, J A; Barraza, P; Araya, J F; Farías, M H; Gonzalez, G; Alonso-Núñez, G Melamine-Assisted Synthesis of Nitrogen-Doped Res2 Nanosheets/Carbon Composites Artículo de revista Materials Letters, 243 , pp. 42-45, 2019, ISSN: 0167-577X. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN54, title = {Melamine-Assisted Synthesis of Nitrogen-Doped Res2 Nanosheets/Carbon Composites}, author = {E Benavente and J A Aliaga and P Barraza and J F Araya and M H Far\'{i}as and G. Gonzalez and G Alonso-N\'{u}\~{n}ez}, url = {http://www.sciencedirect.com/science/article/pii/S0167577X1930196X}, doi = {https://doi.org/10.1016/j.matlet.2019.01.152}, issn = {0167-577X}, year = {2019}, date = {2019-01-01}, journal = {Materials Letters}, volume = {243}, pages = {42-45}, publisher = {2011 Elsevier B.V.}, abstract = {3D hierarchical nitrogen-doped ReS2 nanosheets/carbon composites were obtained by a solvothermal synthesis involving the reaction of Re2(CO)10 with sulfur, melamine and solvents (toluene/water). The incorporation of N atoms in the resulting ReS2/C composites was directed by the aggregation of carbonaceous matter from solvent and melamine, where the composite synthesized with toluene showed higher N content. This synthesis route, based on the selection of solvent, provides a simple approach to incorporate N atoms in a poorly crystalline structure for developing new functional ReS2 materials.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 3D hierarchical nitrogen-doped ReS2 nanosheets/carbon composites were obtained by a solvothermal synthesis involving the reaction of Re2(CO)10 with sulfur, melamine and solvents (toluene/water). The incorporation of N atoms in the resulting ReS2/C composites was directed by the aggregation of carbonaceous matter from solvent and melamine, where the composite synthesized with toluene showed higher N content. This synthesis route, based on the selection of solvent, provides a simple approach to incorporate N atoms in a poorly crystalline structure for developing new functional ReS2 materials. |
González, E A; Leiva, N; Vejar, N; Sancy, M; Gulppi, M; Azócar, M I; Gomez, G; Tamayo, L; Zhou, X; Thompson, G E; Páez, M A Sol–Gel Coatings Doped with Encapsulated Silver Nanoparticles: Inhibition of Biocorrosion on 2024-T3 Aluminum Alloy Promoted by Pseudomonas Aeruginosa Artículo de revista Journal of Materials Research and Technology, 8 (2), pp. 1809-1818, 2019, ISSN: 2238-7854. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN68, title = {Sol\textendashGel Coatings Doped with Encapsulated Silver Nanoparticles: Inhibition of Biocorrosion on 2024-T3 Aluminum Alloy Promoted by Pseudomonas Aeruginosa}, author = {E A Gonz\'{a}lez and N Leiva and N Vejar and M Sancy and M Gulppi and M I Az\'{o}car and G Gomez and L. Tamayo and X Zhou and G E Thompson and M A P\'{a}ez}, url = {http://www.sciencedirect.com/science/article/pii/S2238785418303983}, doi = {https://doi.org/10.1016/j.jmrt.2018.12.011}, issn = {2238-7854}, year = {2019}, date = {2019-01-01}, journal = {Journal of Materials Research and Technology}, volume = {8}, number = {2}, pages = {1809-1818}, abstract = {Silanol type hybrid polymers modified with silver nanoparticles encapsulated with SiO2 for biocorrosion protection of 2024-T3 aluminum alloy were studied through electrochemical characterization and surface analysis techniques. Two different encapsulated silver nanoparticles were synthesized using tetraethoxysilane as a core shell. The hybrid polymer was prepared by the sol\textendashgel technique by mixing tetraethoxysilane and triethyl(octyl)silane in 1-propanol, followed by the incorporation of silver nanoparticles or encapsulated silver nanoparticles. Relatively uniform coatings were observed by a scanning electron microscopy analysis. Transmission electron microscopy and dynamic light scattering results indicated that the diameter of the silver nanoparticles was around 20nm, whereas the encapsulated silver nanoparticles presented diameters between 24 and 30nm. The viability results showed that polymers modified with encapsulated nanoparticles exhibit higher antibacterial properties than the polymer modified with free silver nanoparticles. This fact may be associated with a higher hydrophobicity of the coatings modified with silver encapsulated nanoparticles. Additionally, impedance measurements revealed a protective effect of all synthesized coatings for 2024-T3 aluminum alloy in chloride media inoculated with Pseudomonas aeruginosa.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Silanol type hybrid polymers modified with silver nanoparticles encapsulated with SiO2 for biocorrosion protection of 2024-T3 aluminum alloy were studied through electrochemical characterization and surface analysis techniques. Two different encapsulated silver nanoparticles were synthesized using tetraethoxysilane as a core shell. The hybrid polymer was prepared by the sol–gel technique by mixing tetraethoxysilane and triethyl(octyl)silane in 1-propanol, followed by the incorporation of silver nanoparticles or encapsulated silver nanoparticles. Relatively uniform coatings were observed by a scanning electron microscopy analysis. Transmission electron microscopy and dynamic light scattering results indicated that the diameter of the silver nanoparticles was around 20nm, whereas the encapsulated silver nanoparticles presented diameters between 24 and 30nm. The viability results showed that polymers modified with encapsulated nanoparticles exhibit higher antibacterial properties than the polymer modified with free silver nanoparticles. This fact may be associated with a higher hydrophobicity of the coatings modified with silver encapsulated nanoparticles. Additionally, impedance measurements revealed a protective effect of all synthesized coatings for 2024-T3 aluminum alloy in chloride media inoculated with Pseudomonas aeruginosa. |
Rubio, S; Pérez, F J Aba and Its Signaling Pathway Are Involved in the Cold Acclimation and Deacclimation of Grapevine Buds Artículo de revista Scientia Horticulturae, 256 (39), pp. 108565, 2019, ISSN: 0304-4238. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN64, title = {Aba and Its Signaling Pathway Are Involved in the Cold Acclimation and Deacclimation of Grapevine Buds}, author = {S Rubio and F J P\'{e}rez}, url = {http://www.sciencedirect.com/science/article/pii/S0304423819304546}, doi = {https://doi.org/10.1016/j.scienta.2019.108565}, issn = {0304-4238}, year = {2019}, date = {2019-01-01}, journal = {Scientia Horticulturae}, volume = {256}, number = {39}, pages = {108565}, publisher = {2012 Elsevier Ltd.}, abstract = {The grapevine (Vitis vinifera L.) buds as well as the buds of other deciduous fruit trees acclimate and deacclimate to the cold during the autumn-winter season. Cold acclimation (CA) is characterized by an increase in bud cold-hardiness, while deacclimation (DA) by a loss of it. The mechanisms underlying the transition of the buds from CA to DA are not well understood. In this study, the effect of ABA, LT and ABA + LT on the expression of the genes of the ABA signaling pathway, and the role that these genes and ABA play in the transition of the buds from the CA to the DA was investigated. In vitro experiments carried-out with single-bud cuttings were used to analyze the effect of ABA, LT and ABA + LT treatments on the expression of ABA signaling genes. To study the role of ABA and its signaling pathway in the transition of grapevine buds from CA to DA, applications of ABA and Uniconazole-P (Uni-P), an inhibitor of the enzyme that catabolizes ABA, were performed to the grapevine buds during their period of CA and DA. The results show that : a) VvPP2Cs were the only ABA signaling genes which were induced synergistically by ABA + LT, b) ABA improved the cold-hardiness of the buds only during its period of CA c) Uni-P advanced the appearance of the second peak of ABA in the buds and its transition from the CA to the DA.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The grapevine (Vitis vinifera L.) buds as well as the buds of other deciduous fruit trees acclimate and deacclimate to the cold during the autumn-winter season. Cold acclimation (CA) is characterized by an increase in bud cold-hardiness, while deacclimation (DA) by a loss of it. The mechanisms underlying the transition of the buds from CA to DA are not well understood. In this study, the effect of ABA, LT and ABA + LT on the expression of the genes of the ABA signaling pathway, and the role that these genes and ABA play in the transition of the buds from the CA to the DA was investigated. In vitro experiments carried-out with single-bud cuttings were used to analyze the effect of ABA, LT and ABA + LT treatments on the expression of ABA signaling genes. To study the role of ABA and its signaling pathway in the transition of grapevine buds from CA to DA, applications of ABA and Uniconazole-P (Uni-P), an inhibitor of the enzyme that catabolizes ABA, were performed to the grapevine buds during their period of CA and DA. The results show that : a) VvPP2Cs were the only ABA signaling genes which were induced synergistically by ABA + LT, b) ABA improved the cold-hardiness of the buds only during its period of CA c) Uni-P advanced the appearance of the second peak of ABA in the buds and its transition from the CA to the DA. |
Toro, R; Kvakić, M; Klaić, Z B; Koračin, D; Morales, R G E; Leiva, M A Exploring Atmospheric Stagnation During a Severe Particulate Matter Air Pollution Episode over Complex Terrain in Santiago, Chile Artículo de revista Environmental Pollution, 244 (2), pp. 705-714, 2019, ISSN: 0269-7491. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN56, title = {Exploring Atmospheric Stagnation During a Severe Particulate Matter Air Pollution Episode over Complex Terrain in Santiago, Chile}, author = {R. Toro and M Kvaki\'{c} and Z B Klai\'{c} and D Kora\v{c}in and R.G.E. Morales and M.A. Leiva}, url = {http://www.sciencedirect.com/science/article/pii/S0269749118311461}, doi = {https://doi.org/10.1016/j.envpol.2018.10.067}, issn = {0269-7491}, year = {2019}, date = {2019-01-01}, journal = {Environmental Pollution}, volume = {244}, number = {2}, pages = {705-714}, abstract = {A severe air quality degradation event occurred in the Santiago Metropolitan Area (SMA), Chile, in June 2014. Meteorological and air quality measurements from 11 stations in the area as well as numerical simulations using the Weather and Research Forecasting (WRF) model were used to explain the main reasons for the occurrence of elevated particulate matter (PM) concentrations. The conditions were characterized with formation of a coastal low in central Chile between the southeastern anticyclone and a high-pressure system over Argentina. At a local scale, these conditions generated a depression at the base of the inversion layer, an increase in the vertical thermal stability, lower humidity and low-wind conditions, which were conducive to a decrease in pollutant dispersion and insufficient ventilation of the polluted air. Measurements and simulations using the WRF model revealed a vertical structure of the boundary layer during these stagnant conditions and provided a basis for a trajectory analysis. The back-trajectory calculation showed that the transport of air parcels was contained in the valley during the highest concentrations. The analysis also enabled the definition of the threshold values of a simple indicator of air pollution (ventilation coefficient, VC), which confirmed the evolution of the episode and divided the observed daily concentrations into two groups, with one including values above the limits prescribed by the national air quality standards (NAQS) and the other including values below these limits. For the SMA, the daily PM concentrations above the NASQ limits were associated with an overall mean threshold value of VC below 500 m2 s−1 (for PM2.5) and 300 m2 s−1 (for PM10). To apply the VC analysis to other pollutants and different geographic locations, different threshold values should be evaluated.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A severe air quality degradation event occurred in the Santiago Metropolitan Area (SMA), Chile, in June 2014. Meteorological and air quality measurements from 11 stations in the area as well as numerical simulations using the Weather and Research Forecasting (WRF) model were used to explain the main reasons for the occurrence of elevated particulate matter (PM) concentrations. The conditions were characterized with formation of a coastal low in central Chile between the southeastern anticyclone and a high-pressure system over Argentina. At a local scale, these conditions generated a depression at the base of the inversion layer, an increase in the vertical thermal stability, lower humidity and low-wind conditions, which were conducive to a decrease in pollutant dispersion and insufficient ventilation of the polluted air. Measurements and simulations using the WRF model revealed a vertical structure of the boundary layer during these stagnant conditions and provided a basis for a trajectory analysis. The back-trajectory calculation showed that the transport of air parcels was contained in the valley during the highest concentrations. The analysis also enabled the definition of the threshold values of a simple indicator of air pollution (ventilation coefficient, VC), which confirmed the evolution of the episode and divided the observed daily concentrations into two groups, with one including values above the limits prescribed by the national air quality standards (NAQS) and the other including values below these limits. For the SMA, the daily PM concentrations above the NASQ limits were associated with an overall mean threshold value of VC below 500 m2 s−1 (for PM2.5) and 300 m2 s−1 (for PM10). To apply the VC analysis to other pollutants and different geographic locations, different threshold values should be evaluated. |
Díaz, A; Villanueva, P; Oliva, V; Gil-Durán, C; Fierro, F; Chávez, R; Vaca, I Genetic Transformation of the Filamentous Fungus Pseudogymnoascus Verrucosus of Antarctic Origin Artículo de revista Frontiers in Microbiology, 10 (2675), pp. 632-638, 2019, ISSN: 1664-302X. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN73, title = {Genetic Transformation of the Filamentous Fungus Pseudogymnoascus Verrucosus of Antarctic Origin}, author = {A D\'{i}az and P Villanueva and V Oliva and C Gil-Dur\'{a}n and F Fierro and R Ch\'{a}vez and I. Vaca}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2019.02675}, doi = {10.3389/fmicb.2019.02675}, issn = {1664-302X}, year = {2019}, date = {2019-01-01}, journal = {Frontiers in Microbiology}, volume = {10}, number = {2675}, pages = {632-638}, abstract = {Cold-adapted fungi isolated from Antarctica, in particular those belonging to the genus Pseudogymnoascus, are producers of secondary metabolites with interesting bioactive properties as well as enzymes with potential biotechnological applications. However, at genetic level, the study of these fungi has been hindered by the lack of suitable genetic tools such as transformation systems. In fungi, the availability of transformation systems is a key to address the functional analysis of genes related with the production of a particular metabolite or enzyme. To the best of our knowledge, the transformation of Pseudogymnoascus strains of Antarctic origin has not been achieved yet. In this work, we describe for the first time the successful transformation of a Pseudogymnoascus verrucosus strain of Antarctic origin, using two methodologies: the polyethylene glycol (PEG)-mediated transformation, and the electroporation of germinated conidia. We achieved transformation efficiencies of 15.87 ± 5.16 transformants per μg of DNA and 2.67 ± 1.15 transformants per μg of DNA for PEG-mediated transformation and electroporation of germinated conidia, respectively. These results indicate that PEG-mediated transformation is a very efficient method for the transformation of this Antarctic fungus. The genetic transformation of Pseudogymnoascus verrucosus described in this work represents the first example of transformation of a filamentous fungus of Antarctic origin.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cold-adapted fungi isolated from Antarctica, in particular those belonging to the genus Pseudogymnoascus, are producers of secondary metabolites with interesting bioactive properties as well as enzymes with potential biotechnological applications. However, at genetic level, the study of these fungi has been hindered by the lack of suitable genetic tools such as transformation systems. In fungi, the availability of transformation systems is a key to address the functional analysis of genes related with the production of a particular metabolite or enzyme. To the best of our knowledge, the transformation of Pseudogymnoascus strains of Antarctic origin has not been achieved yet. In this work, we describe for the first time the successful transformation of a Pseudogymnoascus verrucosus strain of Antarctic origin, using two methodologies: the polyethylene glycol (PEG)-mediated transformation, and the electroporation of germinated conidia. We achieved transformation efficiencies of 15.87 ± 5.16 transformants per μg of DNA and 2.67 ± 1.15 transformants per μg of DNA for PEG-mediated transformation and electroporation of germinated conidia, respectively. These results indicate that PEG-mediated transformation is a very efficient method for the transformation of this Antarctic fungus. The genetic transformation of Pseudogymnoascus verrucosus described in this work represents the first example of transformation of a filamentous fungus of Antarctic origin. |
Abdussalam, A; Gomez-Jeria, J S Quantum Chemical Study of the Relationships between Electronic Structure and Corticotropin-Releasing Factor 1 Receptor Binding Inhibition by a Group of Benzazole Derivatives. Artículo de revista Journal of Pharmaceutical and Applied Chemistry, 5 (2), pp. 1-9, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN47, title = {Quantum Chemical Study of the Relationships between Electronic Structure and Corticotropin-Releasing Factor 1 Receptor Binding Inhibition by a Group of Benzazole Derivatives.}, author = {A Abdussalam and J.S. Gomez-Jeria}, url = {http://www.naturalspublishing.com/files/published/77cetdi7880278.pdf}, doi = {http://dx.doi.org/10.18576/jpac/050101}, year = {2019}, date = {2019-01-01}, journal = {Journal of Pharmaceutical and Applied Chemistry}, volume = {5}, number = {2}, pages = {1-9}, publisher = {2010 Wiley Periodicals, Inc.}, abstract = {Raman and surface-enhanced Raman scattering (SERS) spectra of the synthetic carboxy terminal peptide of human chorionic gonadatropin beta-subunit free of carbohydrate moieties (P37) are reported. The spectral analysis is performed on the basis of our reported Raman spectrum and SERS data of oligopeptides displaying selected amino acids sequences MRKDV, ADEDRDA, and LGRGISL. SERS samples of P37 were prepared by coating the solid peptide with metal colloids on a quartz slide. This treatment makes possible to obtain high spectral batch to batch reproducibility. Amino acids components of P37 display net charges and hydrophobic characteristics, which are related to particular structural aspects of the adsorbate-substrate interaction. The spectroscopic results are supported by quantum chemical calculations performed by using extended Huckel theory method for a model of P37 interacting with an Ag surface. The P37-metal interaction is drove by positively charged fragments of selected amino acids, mainly threonine 109, lysine 122, and arginine in positions 114 and 133. Data here reported intend to contribute to the knowledge about the antigen-antibody interaction and to the drugs delivery research area.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Raman and surface-enhanced Raman scattering (SERS) spectra of the synthetic carboxy terminal peptide of human chorionic gonadatropin beta-subunit free of carbohydrate moieties (P37) are reported. The spectral analysis is performed on the basis of our reported Raman spectrum and SERS data of oligopeptides displaying selected amino acids sequences MRKDV, ADEDRDA, and LGRGISL. SERS samples of P37 were prepared by coating the solid peptide with metal colloids on a quartz slide. This treatment makes possible to obtain high spectral batch to batch reproducibility. Amino acids components of P37 display net charges and hydrophobic characteristics, which are related to particular structural aspects of the adsorbate-substrate interaction. The spectroscopic results are supported by quantum chemical calculations performed by using extended Huckel theory method for a model of P37 interacting with an Ag surface. The P37-metal interaction is drove by positively charged fragments of selected amino acids, mainly threonine 109, lysine 122, and arginine in positions 114 and 133. Data here reported intend to contribute to the knowledge about the antigen-antibody interaction and to the drugs delivery research area. |
Briones, X; Villalobos, V; Queneau, Y; Danna, C S; Muñoz, R; Ríos, H E; Pavez, J; Páez, M; Cabrera, R; Tamayo, L; Urzúa, M Surfaces Based on Amino Acid Functionalized Polyelectrolyte Films Towards Active Surfaces for Enzyme Immobilization Artículo de revista Materials Science and Engineering: C, 104 (3), pp. 109938, 2019, ISSN: 0928-4931. Resumen | Enlaces | BibTeX | Etiquetas: Acid Functionalized, Active Surfaces, Enzyme Immobilization @article{RN71, title = {Surfaces Based on Amino Acid Functionalized Polyelectrolyte Films Towards Active Surfaces for Enzyme Immobilization}, author = {X Briones and V Villalobos and Y Queneau and C S Danna and R Mu\~{n}oz and H E R\'{i}os and J Pavez and M P\'{a}ez and R Cabrera and L. Tamayo and M. Urz\'{u}a}, url = {http://www.sciencedirect.com/science/article/pii/S0928493119302875}, doi = {https://doi.org/10.1016/j.msec.2019.109938}, issn = {0928-4931}, year = {2019}, date = {2019-01-01}, journal = {Materials Science and Engineering: C}, volume = {104}, number = {3}, pages = {109938}, abstract = {Surface based on polyelectrolytes functionalized with amino acids onto amino-terminated solid surfaces of silicon wafers was prepared, with the purpose of evaluate the chemical functionality of the polyelectrolyte films in adsorption and catalytic activity of an enzyme. In this work, the adsorption of the enzyme glucose 6-phosphate dehydrogenase from Leuconostoc mesenteroides (LmG6PD) was studied as model. The polyelectrolytes were obtained from poly (maleic anhydride-alt-vinylpyrrolidone) [poly(MA-alt-VP)] and functionalized with amino acids of different hydropathy index: glutamine (Gln), tyrosine (Tyr) and methionine (Met). The polyelectrolytes were adsorbed onto the amino-terminated silicon wafer at pH 3.5 and 4.5 and at low and high ionic strength. At low ionic strength and pH 3.5, the largest quantity of adsorbed polyelectrolyte was on the films containing glutamine moiety as the most hydrophilic amino acid in the side chain of polymer chain (5.88 mg/m2), whereas at high ionic strength and pH 4.5, the lowest quantity was in films containing tyrosine moiety in the side chain (1.88 mg/m2). The films were characterized by ellipsometry, contact angle measurements and atomic force microscopy (AFM). The polyelectrolyte films showed a moderate degree of hydrophobicity, the methionine derivative being the most hydrophobic film. With the aim of evaluate the effect of the amino acid moieties on the ability of the surface to adsorb enzymes, we study the activity of the enzyme on these surfaces. We observed that the polarity of the side chain of the amino acid in the polyelectrolyte affected the quantity of LmG6PD adsorbed, as well as its specific activity, showing that films prepared from poly(MA-alt-VP) functionalized with Met provide the best enzymatic performance. The results obtained demonstrated that the surfaces prepared from polyelectrolytes functionalized with amino acids could be an attractive and simple platform for the immobilization of enzymes, which could be of interest for biocatalysis applications.}, keywords = {Acid Functionalized, Active Surfaces, Enzyme Immobilization}, pubstate = {published}, tppubtype = {article} } Surface based on polyelectrolytes functionalized with amino acids onto amino-terminated solid surfaces of silicon wafers was prepared, with the purpose of evaluate the chemical functionality of the polyelectrolyte films in adsorption and catalytic activity of an enzyme. In this work, the adsorption of the enzyme glucose 6-phosphate dehydrogenase from Leuconostoc mesenteroides (LmG6PD) was studied as model. The polyelectrolytes were obtained from poly (maleic anhydride-alt-vinylpyrrolidone) [poly(MA-alt-VP)] and functionalized with amino acids of different hydropathy index: glutamine (Gln), tyrosine (Tyr) and methionine (Met). The polyelectrolytes were adsorbed onto the amino-terminated silicon wafer at pH 3.5 and 4.5 and at low and high ionic strength. At low ionic strength and pH 3.5, the largest quantity of adsorbed polyelectrolyte was on the films containing glutamine moiety as the most hydrophilic amino acid in the side chain of polymer chain (5.88 mg/m2), whereas at high ionic strength and pH 4.5, the lowest quantity was in films containing tyrosine moiety in the side chain (1.88 mg/m2). The films were characterized by ellipsometry, contact angle measurements and atomic force microscopy (AFM). The polyelectrolyte films showed a moderate degree of hydrophobicity, the methionine derivative being the most hydrophobic film. With the aim of evaluate the effect of the amino acid moieties on the ability of the surface to adsorb enzymes, we study the activity of the enzyme on these surfaces. We observed that the polarity of the side chain of the amino acid in the polyelectrolyte affected the quantity of LmG6PD adsorbed, as well as its specific activity, showing that films prepared from poly(MA-alt-VP) functionalized with Met provide the best enzymatic performance. The results obtained demonstrated that the surfaces prepared from polyelectrolytes functionalized with amino acids could be an attractive and simple platform for the immobilization of enzymes, which could be of interest for biocatalysis applications. |
Navas, D; Donoso, J P; Magon, C; Sotomayor-Torres, C M; Moreno, M; Lozano, H; Benavente, E; Gonzalez, G Ammonium Hexadeca-Oxo-Heptavanadate Microsquares. A New Member in the Family of the V7o16 Mixed-Valence Nanostructures Artículo de revista New Journal of Chemistry, 43 (45), pp. 17548-17556, 2019, ISSN: 1144-0546. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN51, title = {Ammonium Hexadeca-Oxo-Heptavanadate Microsquares. A New Member in the Family of the V7o16 Mixed-Valence Nanostructures}, author = {D Navas and J P Donoso and C Magon and C M Sotomayor-Torres and M Moreno and H Lozano and E Benavente and G. Gonzalez}, url = {http://dx.doi.org/10.1039/C9NJ02188D}, doi = {10.1039/C9NJ02188D}, issn = {1144-0546}, year = {2019}, date = {2019-01-01}, journal = {New Journal of Chemistry}, volume = {43}, number = {45}, pages = {17548-17556}, abstract = {This paper presents a new mixed valence heptavanadate (NH4)2V7O16, obtained from a two-stage treatment in a single container of ammonium metavanadate with hexadecylamine in an acetic medium. The hydrolysis of the precursor under normal conditions leads to an intermediate, layered hybrid nanocomposite, V2O5/alkylamine, which after an in situ hydrothermal treatment is transformed almost quantitatively into an amine-free microcrystalline phase constituted by perfect square microparticles of (NH4)2V7O16. The analysis of composition, structure and morphology of the product points to a mixed valence vanadium oxide with a high content of V(iv) (approximately 73%). The microsquares have a tetragonal structure similar to that of BaV7O16, as well as to those proposed for the VOx/amine hybrid nanocomposite series: nanotubes, nano urchins and the compound (en)V7O16. The results suggest that all these phases belong to the V7O16 family, but that they differ in the amine content, the degree of reduction and the curvature of the network. The feasibility of obtaining flat nanostructures based on V7O16 without templates, beyond demonstrating the robustness of the structural unit V7O16 in networks with different degrees of reduction and curvatures, clarifies the role of alkylamines in this type of anti-entropic supramolecular process. First, the amine provides a stable platform that allows for an orderly reduction of the network under hydrothermal conditions and, when the medium favours the stability of the V\textendashamine bond, the alkylamine contributes to the driving force that leads to the curving of the V\textendashO network.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents a new mixed valence heptavanadate (NH4)2V7O16, obtained from a two-stage treatment in a single container of ammonium metavanadate with hexadecylamine in an acetic medium. The hydrolysis of the precursor under normal conditions leads to an intermediate, layered hybrid nanocomposite, V2O5/alkylamine, which after an in situ hydrothermal treatment is transformed almost quantitatively into an amine-free microcrystalline phase constituted by perfect square microparticles of (NH4)2V7O16. The analysis of composition, structure and morphology of the product points to a mixed valence vanadium oxide with a high content of V(iv) (approximately 73%). The microsquares have a tetragonal structure similar to that of BaV7O16, as well as to those proposed for the VOx/amine hybrid nanocomposite series: nanotubes, nano urchins and the compound (en)V7O16. The results suggest that all these phases belong to the V7O16 family, but that they differ in the amine content, the degree of reduction and the curvature of the network. The feasibility of obtaining flat nanostructures based on V7O16 without templates, beyond demonstrating the robustness of the structural unit V7O16 in networks with different degrees of reduction and curvatures, clarifies the role of alkylamines in this type of anti-entropic supramolecular process. First, the amine provides a stable platform that allows for an orderly reduction of the network under hydrothermal conditions and, when the medium favours the stability of the V–amine bond, the alkylamine contributes to the driving force that leads to the curving of the V–O network. |
Crous, P W; Wingfield, M J; Lombard, L; Roets, F; Swart, W J; Alvarado, P; Carnegie, A J; Moreno, G; Luangsa-Ard, J; Thangavel, R; Alexandrova, A V; Baseia, I G; Bellanger, J M; Bessette, A E; Bessette, A R; Delapeña-Lastra, S; García, D; Gené, J; Pham, T H G; Heykoop, M; Malysheva, E; Malysheva, V; Martín, M P; Morozova, O V; Noisripoom, W; Overton, B E; Rea, A E; Sewall, B J; Smith, M E; Smyth, C W; Tasanathai, K; Visagie, C M; Adam, ; Ík, S; Alves, A; Andrade, J P; Aninat, M J; Araújo, R V B; Bordallo, J J; Boufleur, T; Baroncelli, R; Barreto, R W; Bolin, J; Cabero, J; Cabo, ; M., ; Cafà, G; Caffot, M L H; Cai, L; Carlavilla, J R; Chávez, R; Decastro, R R L; Delgat, L; Deschuyteneer, D; Dios, M M; Domínguez, L S; Evans, H C; Eyssartier, G; Ferreira, B W; Figueiredo, C N; Liu, F; Fournier, J; Galli-Terasawa, L V; Gil-Durán, C; Glienke, C; Gonçalves, M F M; Gryta, H; Guarro, J; Himaman, W; Hywel-Jones, N; Iturrieta-González, I; Ivanushkina, N E; Jargeat, P; Khalid, A N; Khan, J; Kiran, M; Kiss, L; Kochkina, G A; Kola, ; Ík, M; Kubátová, A; Lodge, D J; Loizides, M; Luque, D; Manjón, J L; a Marbach, P S; Massolajr, N S; Mata, M; Miller, A N; Mongkolsamrit, S; Moreau, P A; Morte, A; Mujic, A; Navarro-Ródenas, A; Németh, M Z; Nóbrega, T F; Nováková, A; Olariaga, I; Ozerskaya, S M; Palma, M A; a Petters-Vandresen, D L; Piontelli, E; Popov, E S; Rodríguez, A; Requejo, Ó; Rodrigues, A C M; Rong, I H; Roux, J; Seifert, K A; Silva, B D B; Sklená, ; F., ; Smith, J A; Sousa, J O; Souza, H G; Desouza, J T; Vec, K; Tanchaud, P; Tanney, J B; Terasawa, F; Thanakitpipattana, D; Torres-Garcia, D; Vaca, I; Vaghefi, N; Vaniperen, A L; Vasilenko, O V; Verbeken, A; Yilmaz, N; Zamora, J C; Zapata, M; Jurjevi, ; Groenewald, J Z Fungal Planet Description Sheets Artículo de revista Persoonia - Molecular Phylogeny and Evolution of Fungi, 43 (1), pp. 223-425, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN74, title = {Fungal Planet Description Sheets}, author = {P W Crous and M J Wingfield and L Lombard and F Roets and W J Swart and P Alvarado and A J Carnegie and G Moreno and J Luangsa-Ard and R Thangavel and A V Alexandrova and I G Baseia and J M Bellanger and A E Bessette and A R Bessette and S Delape\~{n}a-Lastra and D Garc\'{i}a and J Gen\'{e} and T H G Pham and M Heykoop and E Malysheva and V Malysheva and M P Mart\'{i}n and O V Morozova and W Noisripoom and B E Overton and A E Rea and B J Sewall and M E Smith and C W Smyth and K Tasanathai and C M Visagie and Adam and S \'{I}k and A Alves and J P Andrade and M J Aninat and R V B Ara\'{u}jo and J J Bordallo and T Boufleur and R Baroncelli and R W Barreto and J Bolin and J Cabero and Cabo and M. and G Caf\`{a} and M L H Caffot and L Cai and J R Carlavilla and R Ch\'{a}vez and R R L Decastro and L Delgat and D Deschuyteneer and M M Dios and L S Dom\'{i}nguez and H C Evans and G Eyssartier and B W Ferreira and C N Figueiredo and F Liu and J Fournier and L V Galli-Terasawa and C Gil-Dur\'{a}n and C Glienke and M F M Gon\c{c}alves and H Gryta and J Guarro and W Himaman and N Hywel-Jones and I Iturrieta-Gonz\'{a}lez and N E Ivanushkina and P Jargeat and A N Khalid and J Khan and M Kiran and L Kiss and G A Kochkina and Kola and M \'{I}k and A Kub\'{a}tov\'{a} and D J Lodge and M Loizides and D Luque and J L Manj\'{o}n and P a S Marbach and N S Massolajr and M Mata and A N Miller and S Mongkolsamrit and P A Moreau and A Morte and A Mujic and A Navarro-R\'{o}denas and M Z N\'{e}meth and T F N\'{o}brega and A Nov\'{a}kov\'{a} and I Olariaga and S M Ozerskaya and M A Palma and D a L Petters-Vandresen and E Piontelli and E S Popov and A Rodr\'{i}guez and \'{O} Requejo and A C M Rodrigues and I H Rong and J Roux and K A Seifert and B D B Silva and Sklen\'{a} and F. and J A Smith and J O Sousa and H G Souza and J T Desouza and K Vec and P Tanchaud and J B Tanney and F Terasawa and D Thanakitpipattana and D Torres-Garcia and I. Vaca and N Vaghefi and A L Vaniperen and O V Vasilenko and A Verbeken and N Yilmaz and J C Zamora and M Zapata and Jurjevi and J Z Groenewald}, url = {https://www.ingentaconnect.com/content/nhn/pimj/2019/00000043/00000001/art00007 https://doi.org/10.3767/persoonia.2019.43.06}, doi = {10.3767/persoonia.2019.43.06}, year = {2019}, date = {2019-01-01}, journal = {Persoonia - Molecular Phylogeny and Evolution of Fungi}, volume = {43}, number = {1}, pages = {223-425}, abstract = {Novel species of fungi described in this study include those from various countries as follows: \textbf{Antarctica} , \textit{Apenidiella antarctica} from permafrost, \textit{Cladosporium fildesense} from an unidentified marine sponge. \textbf{Argentina} , \textit{Geastrum wrightii} on humus in mixed forest. \textbf{Australia} , \textit{Golovinomyces glandulariae} on \textit{Glandularia aristigera, Neoanungitea eucalyptorum} on leaves of \textit{Eucalyptus grandis, Teratosphaeria corymbiicola} on leaves of \textit{ Corymbia ficifolia, Xylaria eucalypti} on leaves of \textit{Eucalyptus radiata.} \textbf{Brazil} , \textit{Bovista psammophila} on soil, \textit{Fusarium awaxy} on rotten stalks of \textit{Zea mays, Geastrum lanuginosum} on leaf litter covered soil, \textit{Hermetothecium mikaniae-micranthae} (incl. \textit{Hermetothecium} gen. nov.)on \textit{Mikania micrantha, Penicillium reconvexovelosoi} in soil, \textit{Stagonosporopsis vannaccii} from pod of \textit{Glycine max.} \textbf{British Virgin Isles}, \textit{Lactifluus guanensis} on soil. \textbf{Canada} , \textit{Sorocybe oblongispora} on resin of \textit{Picea rubens.} \textbf{Chile} , \textit{Colletotrichum roseum} on leaves of \textit{Lapageria rosea.} \textbf{China}, \textit{Setophoma caverna} from carbonatite in Karst cave. \textbf{Colombia} , \textit{Lareunionomyces eucalypticola} on leaves of \textit{Eucalyptus grandis.} \textbf{Costa Rica} , \textit{Psathyrella pivae} on wood. \textbf{Cyprus}, \textit{Clavulina iris} on calcareous substrate. \textbf{France}, \textit{Chromosera ambigua} and \textit{Clavulina iris} var. \textit{occidentalis} on soil. \textbf{French West Indies}, \textit{Helminthosphaeria hispidissima} on dead wood. \textbf{Guatemala} , \textit{Talaromyces guatemalensis} in soil. \textbf{Malaysia}, \textit{Neotracylla pini} (incl. \textit{Tracyllales} ord. nov. and \textit{Neotra- cylla} gen. nov.)and \textit{Vermiculariopsiella pini} on needles of \textit{Pinus tecunumanii.} \textbf{New Zealand} , \textit{Neoconiothyrium viticola} on stems of \textit{Vitis vinifera, Parafenestella pittospori} on \textit{Pittosporum tenuifolium, Pilidium novae-zelandiae} on \textit{Phoenix} sp. \textbf{Pakistan} , \textit{Russula quercus-floribundae} on forest floor. \textbf{Portugal}, \textit{Trichoderma aestuarinum} from saline water. \textbf{Russia}, \textit{Pluteus liliputianus} on fallen branch of deciduous tree, \textit{Pluteus spurius} on decaying deciduous wood or soil. \textbf{South Africa}, \textit{Alloconiothyrium encephalarti, Phyllosticta encephalarticola} and \textit{Neothyrostroma encephalarti} (incl. \textit{ Neothyrostroma} gen. nov.)on leaves of \textit{Encephalartos} sp., \textit{Chalara eucalypticola} on leaf spots of \textit{Eucalyptus grandis} × \textit{urophylla, Clypeosphaeria oleae} on leaves of \textit{Olea capensis, Cylindrocladiella postalofficium} on leaf litter of \textit{Sideroxylon inerme}, \textit{Cylindromonium eugeniicola} (incl. \textit{Cylindromonium} gen. nov.)on leaf litter of \textit{Eugenia capensis}, \textit{Cyphellophora goniomatis} on leaves of \textit{Gonioma kamassi}, \textit{ Nothodactylaria nephrolepidis} (incl. \textit{Nothodactylaria} gen. nov. and \textit{Nothodactylariaceae} fam. nov.)on leaves of \textit{Nephrolepis exaltata} , \textit{Falcocladium eucalypti} and \textit{Gyrothrix eucalypti} on leaves of \textit{Eucalyptus} sp., \textit{Gyrothrix oleae} on leaves of \textit{Olea capensis} subsp. \textit{macrocarpa}, \textit{Harzia metrosideri} on leaf litter of \textit{Metrosideros} sp., \textit{Hippopotamyces phragmitis} (incl. \textit{Hippopota-myces} gen. nov.)on leaves of \textit{ Phragmites australis}, \textit{Lectera philenopterae} on \textit{Philenoptera violacea} , \textit{Leptosillia mayteni} on leaves of \textit{Maytenus heterophylla} , \textit{Lithohypha aloicola} and \textit{Neoplatysporoides aloes} on leaves of \textit{Aloe} sp., \textit{Millesimomyces rhoicissi} (incl. \textit{Millesimomyces} gen. nov.) on leaves of \textit{Rhoicissus digitata}, \textit{Neodevriesia strelitziicola} on leaf litter of \textit{Strelitzia nicolai}, \textit{Neokirramyces syzygii} (incl. \textit{Neokirramyces} gen. nov.)on leaf spots of \textit{Syzygium} sp., \textit{Nothoramichloridium perseae} (incl. \textit{Nothoramichloridium} gen.nov.and \textit{Anungitiomycetaceae} fam. nov.)on leaves of \textit{Persea americana}, \textit{Paramycosphaerella watsoniae} on leaf spots of \textit{Watsonia} sp., \textit{Penicillium cuddlyae} from dog food, \textit{Podocarpomyces knysnanus} (incl. \textit{Podocarpomyces,} gen.nov.)on leaves of \textit{Podocarpus falcatus}, \textit{Pseudocercospora heteropyxidicola} on leaf spots of \textit{Heteropyxis natalensis}, \textit{Pseudopenidiella podocarpi}, \textit{Scolecobasidium podocarpi} and \textit{Ceramothyrium podocarpicola} on leaves of \textit{Podocarpus latifolius}, \textit{Scolecobasidium blechni} on leaves of \textit{Blechnum capense}, \textit{Stomiopeltis syzygii} on leaves of \textit{Syzygium chordatum}, \textit{Strelitziomyces knysnanus} (incl. \textit{Strelitziomyces} gen.nov.)on leaves of \textit{Strelitzia alba}, \textit{Talaromyces clemensii} from rotting wood in goldmine, \textit{Verrucocladosporium visseri} on \textit{Carpobrotus edulis}. \textbf{Spain}, \textit{Boletopsis mediterraneensis} on soil, \textit{Calycina cortegadensisi} on a living twig of \textit{Castanea sativa}, \textit{Emmonsiellopsis tuberculata} in fluvial sediments, \textit{Mollisia \textit{cor-tegadensis} on dead attached twig of \textit{Quercus robur}, \textit{Psathyrella ovispora} on soil, \textit{Pseudobeltrania lauri} on leaf litter of \textit{Laurus azorica}, \textit{Terfezia dunensis} in soil, \textit{Tuber lucentum} in soil, \textit{Venturia submersa} on submerged plant debris. \textbf{Thailand,/b>, \textit{Cordyceps jakajanicola} on cicada nymph, \textit{Cordyceps kuiburiensis} on spider, \textit{Distoseptispora caricis} on leaves of \textit{Carex} sp., \textit{Ophiocordyceps khonkaenensis on cicada} nymph. \textbf{USA}, \textit{Cytosporella juncicola} and \textit{Davidiello- myces juncicola} on culms of \textit{Juncus effusus}, \textit{Monochaetia massachusettsianum} from air sample, \textit{Neohelicomyces melaleucae} and \textit{Periconia neobrittanica} on leaves of \textit{Melaleuca styphelioides} ?? \textit{lanceolata}, \textit{Pseudocamarosporium eucalypti} on leaves of \textit{Eucalyptus} sp., \textit{Pseudogymnoascus lindneri} from sediment in a mine, \textit{Pseudogymnoascus turneri} from sediment in a railroad tunnel, \textit{Pulchroboletus sclerotiorum} on soil, \textit{Zygosporium pseudomasonii} on leaf of \textit{Serenoa repens}. \textbf{Vietnam}, \textit{Boletus candidissimus} and \textit{Veloporphyrellus vulpinus} on soil.Morphological and culture characteristics are supported by DNA barcodes.} }}, keywords = {}, pubstate = {published}, tppubtype = {article} } Novel species of fungi described in this study include those from various countries as follows: Antarctica , Apenidiella antarctica from permafrost, Cladosporium fildesense from an unidentified marine sponge. Argentina , Geastrum wrightii on humus in mixed forest. Australia , Golovinomyces glandulariae on Glandularia aristigera, Neoanungitea eucalyptorum on leaves of Eucalyptus grandis, Teratosphaeria corymbiicola on leaves of Corymbia ficifolia, Xylaria eucalypti on leaves of Eucalyptus radiata. Brazil , Bovista psammophila on soil, Fusarium awaxy on rotten stalks of Zea mays, Geastrum lanuginosum on leaf litter covered soil, Hermetothecium mikaniae-micranthae (incl. Hermetothecium gen. nov.)on Mikania micrantha, Penicillium reconvexovelosoi in soil, Stagonosporopsis vannaccii from pod of Glycine max. British Virgin Isles, Lactifluus guanensis on soil. Canada , Sorocybe oblongispora on resin of Picea rubens. Chile , Colletotrichum roseum on leaves of Lapageria rosea. China, Setophoma caverna from carbonatite in Karst cave. Colombia , Lareunionomyces eucalypticola on leaves of Eucalyptus grandis. Costa Rica , Psathyrella pivae on wood. Cyprus, Clavulina iris on calcareous substrate. France, Chromosera ambigua and Clavulina iris var. occidentalis on soil. French West Indies, Helminthosphaeria hispidissima on dead wood. Guatemala , Talaromyces guatemalensis in soil. Malaysia, Neotracylla pini (incl. Tracyllales ord. nov. and Neotra- cylla gen. nov.)and Vermiculariopsiella pini on needles of Pinus tecunumanii. New Zealand , Neoconiothyrium viticola on stems of Vitis vinifera, Parafenestella pittospori on Pittosporum tenuifolium, Pilidium novae-zelandiae on Phoenix sp. Pakistan , Russula quercus-floribundae on forest floor. Portugal, Trichoderma aestuarinum from saline water. Russia, Pluteus liliputianus on fallen branch of deciduous tree, Pluteus spurius on decaying deciduous wood or soil. South Africa, Alloconiothyrium encephalarti, Phyllosticta encephalarticola and Neothyrostroma encephalarti (incl. Neothyrostroma gen. nov.)on leaves of Encephalartos sp., Chalara eucalypticola on leaf spots of Eucalyptus grandis × urophylla, Clypeosphaeria oleae on leaves of Olea capensis, Cylindrocladiella postalofficium on leaf litter of Sideroxylon inerme, Cylindromonium eugeniicola (incl. Cylindromonium gen. nov.)on leaf litter of Eugenia capensis, Cyphellophora goniomatis on leaves of Gonioma kamassi, Nothodactylaria nephrolepidis (incl. Nothodactylaria gen. nov. and Nothodactylariaceae fam. nov.)on leaves of Nephrolepis exaltata , Falcocladium eucalypti and Gyrothrix eucalypti on leaves of Eucalyptus sp., Gyrothrix oleae on leaves of Olea capensis subsp. macrocarpa, Harzia metrosideri on leaf litter of Metrosideros sp., Hippopotamyces phragmitis (incl. Hippopota-myces gen. nov.)on leaves of Phragmites australis, Lectera philenopterae on Philenoptera violacea , Leptosillia mayteni on leaves of Maytenus heterophylla , Lithohypha aloicola and Neoplatysporoides aloes on leaves of Aloe sp., Millesimomyces rhoicissi (incl. Millesimomyces gen. nov.) on leaves of Rhoicissus digitata, Neodevriesia strelitziicola on leaf litter of Strelitzia nicolai, Neokirramyces syzygii (incl. Neokirramyces gen. nov.)on leaf spots of Syzygium sp., Nothoramichloridium perseae (incl. Nothoramichloridium gen.nov.and Anungitiomycetaceae fam. nov.)on leaves of Persea americana, Paramycosphaerella watsoniae on leaf spots of Watsonia sp., Penicillium cuddlyae from dog food, Podocarpomyces knysnanus (incl. Podocarpomyces, gen.nov.)on leaves of Podocarpus falcatus, Pseudocercospora heteropyxidicola on leaf spots of Heteropyxis natalensis, Pseudopenidiella podocarpi, Scolecobasidium podocarpi and Ceramothyrium podocarpicola on leaves of Podocarpus latifolius, Scolecobasidium blechni on leaves of Blechnum capense, Stomiopeltis syzygii on leaves of Syzygium chordatum, Strelitziomyces knysnanus (incl. Strelitziomyces gen.nov.)on leaves of Strelitzia alba, Talaromyces clemensii from rotting wood in goldmine, Verrucocladosporium visseri on Carpobrotus edulis. Spain, Boletopsis mediterraneensis on soil, Calycina cortegadensisi on a living twig of Castanea sativa, Emmonsiellopsis tuberculata in fluvial sediments, Mollisia cor-tegadensis on dead attached twig of Quercus robur, Psathyrella ovispora on soil, Pseudobeltrania lauri on leaf litter of Laurus azorica, Terfezia dunensis in soil, Tuber lucentum in soil, Venturia submersa on submerged plant debris. Thailand,/b>, Cordyceps jakajanicola on cicada nymph, Cordyceps kuiburiensis on spider, Distoseptispora caricis on leaves of Carex sp., Ophiocordyceps khonkaenensis on cicada nymph. USA, Cytosporella juncicola and Davidiello- myces juncicola on culms of Juncus effusus, Monochaetia massachusettsianum from air sample, Neohelicomyces melaleucae and Periconia neobrittanica on leaves of Melaleuca styphelioides ?? lanceolata, Pseudocamarosporium eucalypti on leaves of Eucalyptus sp., Pseudogymnoascus lindneri from sediment in a mine, Pseudogymnoascus turneri from sediment in a railroad tunnel, Pulchroboletus sclerotiorum on soil, Zygosporium pseudomasonii on leaf of Serenoa repens. Vietnam, Boletus candidissimus and Veloporphyrellus vulpinus on soil.Morphological and culture characteristics are supported by DNA barcodes. |
Toro-Sazo, M; Brea, J; Loza, M I; Cimadevila, M; Cassels, B K 5-Ht2 Receptor Binding, Functional Activity and Selectivity in N-Benzyltryptamines Artículo de revista PLOS ONE, 14 (1), pp. e0209804, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN9, title = {5-Ht2 Receptor Binding, Functional Activity and Selectivity in N-Benzyltryptamines}, author = {M Toro-Sazo and J Brea and M I Loza and M Cimadevila and B.K. Cassels}, url = {https://doi.org/10.1371/journal.pone.0209804}, doi = {10.1371/journal.pone.0209804}, year = {2019}, date = {2019-01-01}, journal = {PLOS ONE}, volume = {14}, number = {1}, pages = {e0209804}, abstract = {The last fifteen years have seen the emergence and overflow into the drug scene of “superpotent” N-benzylated phenethylamines belonging to the “NBOMe” series, accompanied by numerous research articles. Although N-benzyl substitution of 5-methoxytryptamine is known to increase its affinity and potency at 5-HT2 receptors associated with psychedelic activity, N-benzylated tryptamines have been studied much less than their phenethylamine analogs. To further our knowledge of the activity of N-benzyltryptamines, we have synthesized a family of tryptamine derivatives and, for comparison, a few 5-methoxytryptamine analogs with many different substitution patterns on the benzyl moiety, and subjected them to in vitro affinity and functional activity assays vs. the human 5-HT2 receptor subtypes. In the binding (radioligand displacement) studies some of these compounds exhibited only modest selectivity for either 5-HT2A or 5-HT2C receptors suggesting that a few of them, with affinities in the 10\textendash100 nanomolar range for 5-HT2A receptors, might presumably be psychedelic. Unexpectedly, their functional (calcium mobilization) assays reflected very different trends. All of these compounds proved to be 5-HT2C receptor full agonists while most of them showed low efficacy at the 5-HT2A subtype. Furthermore, several showed moderate-to-strong preferences for activation of the 5-HT2C subtype at nanomolar concentrations. Thus, although some N-benzyltryptamines might be abuse-liable, others might represent new leads for the development of therapeutics for weight loss, erectile dysfunction, drug abuse, or schizophrenia.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The last fifteen years have seen the emergence and overflow into the drug scene of “superpotent” N-benzylated phenethylamines belonging to the “NBOMe” series, accompanied by numerous research articles. Although N-benzyl substitution of 5-methoxytryptamine is known to increase its affinity and potency at 5-HT2 receptors associated with psychedelic activity, N-benzylated tryptamines have been studied much less than their phenethylamine analogs. To further our knowledge of the activity of N-benzyltryptamines, we have synthesized a family of tryptamine derivatives and, for comparison, a few 5-methoxytryptamine analogs with many different substitution patterns on the benzyl moiety, and subjected them to in vitro affinity and functional activity assays vs. the human 5-HT2 receptor subtypes. In the binding (radioligand displacement) studies some of these compounds exhibited only modest selectivity for either 5-HT2A or 5-HT2C receptors suggesting that a few of them, with affinities in the 10–100 nanomolar range for 5-HT2A receptors, might presumably be psychedelic. Unexpectedly, their functional (calcium mobilization) assays reflected very different trends. All of these compounds proved to be 5-HT2C receptor full agonists while most of them showed low efficacy at the 5-HT2A subtype. Furthermore, several showed moderate-to-strong preferences for activation of the 5-HT2C subtype at nanomolar concentrations. Thus, although some N-benzyltryptamines might be abuse-liable, others might represent new leads for the development of therapeutics for weight loss, erectile dysfunction, drug abuse, or schizophrenia. |
Chibwe, L; Manzano, C A; Muir, D; Atkinson, B; Kirk, J L; Marvin, C H; Wang, X; Teixeira, C; Shang, D; Harner, T; Silva, De A O Deposition and Source Identification of Nitrogen Heterocyclic Polycyclic Aromatic Compounds in Snow, Sediment, and Air Samples from the Athabasca Oil Sands Region Artículo de revista Environmental Science & Technology, 53 (6), pp. 2981-2989, 2019, ISSN: 0013-936X. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN58, title = {Deposition and Source Identification of Nitrogen Heterocyclic Polycyclic Aromatic Compounds in Snow, Sediment, and Air Samples from the Athabasca Oil Sands Region}, author = {L Chibwe and C A Manzano and D Muir and B Atkinson and J L Kirk and C H Marvin and X Wang and C Teixeira and D Shang and T Harner and A O De Silva}, url = {https://doi.org/10.1021/acs.est.8b06175}, doi = {10.1021/acs.est.8b06175}, issn = {0013-936X}, year = {2019}, date = {2019-01-01}, journal = {Environmental Science & Technology}, volume = {53}, number = {6}, pages = {2981-2989}, abstract = {The family Trimusculidae produces labdane diterpenes, which differ in the degree and type of esterification with acetoxy and isovaleroyl ester predominantly. Here we describe the isolation from the marine pulmonate Trimusculus peruvianus, collected on intertidal rocks of Chilean coasts, of a new diterpene closely related to the above mentioned characteristics. It structure was determined by spectroscopic data. The compounds were subjected to toxicity tests using nauplii and cysts of Artemia salina. The known compounds isolated in this study have shown an ability to inhibit egg hatch of A. salina.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The family Trimusculidae produces labdane diterpenes, which differ in the degree and type of esterification with acetoxy and isovaleroyl ester predominantly. Here we describe the isolation from the marine pulmonate Trimusculus peruvianus, collected on intertidal rocks of Chilean coasts, of a new diterpene closely related to the above mentioned characteristics. It structure was determined by spectroscopic data. The compounds were subjected to toxicity tests using nauplii and cysts of Artemia salina. The known compounds isolated in this study have shown an ability to inhibit egg hatch of A. salina. |
Rubio, S; Noriega, X; Pérez, F J Aba Promotes Starch Synthesis and Storage Metabolism in Dormant Grapevine Buds Artículo de revista Journal of Plant Physiology, 234-235 (11), pp. 1-8, 2019, ISSN: 0176-1617. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN66, title = {Aba Promotes Starch Synthesis and Storage Metabolism in Dormant Grapevine Buds}, author = {S Rubio and X Noriega and F J P\'{e}rez}, url = {http://www.sciencedirect.com/science/article/pii/S0176161718305443}, doi = {https://doi.org/10.1016/j.jplph.2019.01.004}, issn = {0176-1617}, year = {2019}, date = {2019-01-01}, journal = {Journal of Plant Physiology}, volume = {234-235}, number = {11}, pages = {1-8}, publisher = {2012 John Wiley & Sons, Ltd.}, abstract = {In grapevine (Vitis vinifera L.) buds, the short day (SD)-photoperiod induces endodormancy and increases the level of ABA and the expression of ABA key biosynthesis genes, which suggests that ABA could be the mediator of the photoperiodic induction of endodormancy. In the present study, it was established that during the development of the endodormancy, the content of ABA and the accumulation of starch increased in parallel in the buds; however, these increases occurred after the buds were already in the state of endodormancy. Despite this finding the exogenous applications of ABA to single-bud cuttings increased the starch content and up-regulated the expression of starch synthesis genes (VvSS1 and VvSS3) and down-regulated the expression of sucrose metabolism genes, invertase (VvINV) and sucrose phosphate synthase (VvSUPS). In addition, the manipulation of the endogenous content of ABA in the grapevine buds by applications of hydrogen cyanamide and uniconazole-P, revealed that the depth of the endodormancy depends on the ABA levels. Taken together, the results indicate that the development of the endodormancy in grapevine buds is associated with the accumulation of starch and a shift in metabolism towards a storage metabolism; as ABA stimulates both processes, it must play an important role in the maintenance and release but not the induction of endodormancy in grapevine buds.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In grapevine (Vitis vinifera L.) buds, the short day (SD)-photoperiod induces endodormancy and increases the level of ABA and the expression of ABA key biosynthesis genes, which suggests that ABA could be the mediator of the photoperiodic induction of endodormancy. In the present study, it was established that during the development of the endodormancy, the content of ABA and the accumulation of starch increased in parallel in the buds; however, these increases occurred after the buds were already in the state of endodormancy. Despite this finding the exogenous applications of ABA to single-bud cuttings increased the starch content and up-regulated the expression of starch synthesis genes (VvSS1 and VvSS3) and down-regulated the expression of sucrose metabolism genes, invertase (VvINV) and sucrose phosphate synthase (VvSUPS). In addition, the manipulation of the endogenous content of ABA in the grapevine buds by applications of hydrogen cyanamide and uniconazole-P, revealed that the depth of the endodormancy depends on the ABA levels. Taken together, the results indicate that the development of the endodormancy in grapevine buds is associated with the accumulation of starch and a shift in metabolism towards a storage metabolism; as ABA stimulates both processes, it must play an important role in the maintenance and release but not the induction of endodormancy in grapevine buds. |
Gomez-Jeria, J S Biology and Philosophy. Vii. Sokrates, the Demigod. Artículo de revista World Journal of Research and Review,, 9 (2), pp. 26-30, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN45, title = {Biology and Philosophy. Vii. Sokrates, the Demigod.}, author = {J.S. Gomez-Jeria}, url = {https://www.wjrr.org/download_data/WJRR0901009.pdf}, doi = {10.31871/WJRR.9.1.9}, year = {2019}, date = {2019-01-01}, journal = {World Journal of Research and Review,}, volume = {9}, number = {2}, pages = {26-30}, abstract = {The new solid solutions AgPbSb1-xBixS3 were prepared by solid state reactions. The phases were characterized by powder X-ray diffractions (XRD), scanning electron microscopy, and thermal analysis. The XRD patterns of different members (x=0.5, 0.7, 0.8, and 1.0) are consistent with pure phases crystallizing in the cubic PbStype structure. The electrical characterization was carried out using ac impedance spectroscopy and dc methods. The temperature dependence of the dc conductivity shows typical semiconductor Arrhenius behavior. The impedance measurements were performed in the frequency range of 0.1 Hz to 10 MHz and at the temperature range of 15 degrees C to 350 degrees C. The ac conductivity conforms to Jonscher's universal power law. The frequency dependence of the dielectric permittivity follows the normal dielectric material behavior, and the relaxation is thermally activated. The frequency and temperature dependences of the electrical data are found to follow Summerfield scaling formalism.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The new solid solutions AgPbSb1-xBixS3 were prepared by solid state reactions. The phases were characterized by powder X-ray diffractions (XRD), scanning electron microscopy, and thermal analysis. The XRD patterns of different members (x=0.5, 0.7, 0.8, and 1.0) are consistent with pure phases crystallizing in the cubic PbStype structure. The electrical characterization was carried out using ac impedance spectroscopy and dc methods. The temperature dependence of the dc conductivity shows typical semiconductor Arrhenius behavior. The impedance measurements were performed in the frequency range of 0.1 Hz to 10 MHz and at the temperature range of 15 degrees C to 350 degrees C. The ac conductivity conforms to Jonscher's universal power law. The frequency dependence of the dielectric permittivity follows the normal dielectric material behavior, and the relaxation is thermally activated. The frequency and temperature dependences of the electrical data are found to follow Summerfield scaling formalism. |
Cassels, B K Alkaloids of the Cactaceae — the Classics Artículo de revista Natural Product Communications, 14 (1), pp. 1934578X1901400123, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN7, title = {Alkaloids of the Cactaceae \textemdash the Classics}, author = {B K Cassels}, url = {https://journals.sagepub.com/doi/abs/10.1177/1934578X1901400123}, doi = {10.1177/1934578x1901400123}, year = {2019}, date = {2019-01-01}, journal = {Natural Product Communications}, volume = {14}, number = {1}, pages = {1934578X1901400123}, publisher = {2011 Elsevier B.V.}, abstract = {Alkaloids of the Cactaceae have been studied for the last 120 years. The first half of that period provided the “classic” compounds, after which a large number of usually very similar analogs were isolated or determined with modern methods. Although some unusual synthetic approaches have been developed, their preparation is generally quite straightforward. Their biosynthesis has been studied but, particularly in the case of the isoquinoline compounds, important aspects have not been addressed. Due to its striking effects, the pharmacology of mescaline has been studied more intensely than that of the other phenethylamines present in cacti, followed only by hordenine. The many 1,2,3,4-tetrahydroisoquinoline alkaloids have attracted much less interest and have often been considered practically inactive. Nevertheless, some recorded activities of this group of compounds suggests a need for additional studies, especially in connection with their co-administration with mescaline, as in dried cacti and in beverages prepared from them.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Alkaloids of the Cactaceae have been studied for the last 120 years. The first half of that period provided the “classic” compounds, after which a large number of usually very similar analogs were isolated or determined with modern methods. Although some unusual synthetic approaches have been developed, their preparation is generally quite straightforward. Their biosynthesis has been studied but, particularly in the case of the isoquinoline compounds, important aspects have not been addressed. Due to its striking effects, the pharmacology of mescaline has been studied more intensely than that of the other phenethylamines present in cacti, followed only by hordenine. The many 1,2,3,4-tetrahydroisoquinoline alkaloids have attracted much less interest and have often been considered practically inactive. Nevertheless, some recorded activities of this group of compounds suggests a need for additional studies, especially in connection with their co-administration with mescaline, as in dried cacti and in beverages prepared from them. |
Segovia, M; Alegría, M; Aliaga, J; Celedon, S; Ballesteros, L; Sotomayor-Torres, C; Gonzalez, G; Benavente, E Heterostructured 2d Zno Hybrid Nanocomposites Sensitized with Cubic Cu2o Nanoparticles for Sunlight Photocatalysis Artículo de revista Journal of Materials Science, 54 (21), pp. 13523-13536, 2019, ISSN: 1573-4803. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN53, title = {Heterostructured 2d Zno Hybrid Nanocomposites Sensitized with Cubic Cu2o Nanoparticles for Sunlight Photocatalysis}, author = {M Segovia and M Alegr\'{i}a and J Aliaga and S Celedon and L Ballesteros and C Sotomayor-Torres and G. Gonzalez and E Benavente}, url = {https://doi.org/10.1007/s10853-019-03878-x}, doi = {10.1007/s10853-019-03878-x}, issn = {1573-4803}, year = {2019}, date = {2019-01-01}, journal = {Journal of Materials Science}, volume = {54}, number = {21}, pages = {13523-13536}, abstract = {In this research, we report a series of new heterostructured hybrid 2D ZnO nanocomposites sensitized with Cu2O nanoparticles for sunlight photocatalysis. The Cu2O nanoparticles were synthesized by a surfactant-free method and size reduced by a solvothermal method. 2D ZnO/Cu2O composites were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, reflectance diffuse spectroscopy and Fourier transform infrared. The results showed that the product is a material comprised of layered hybrid 2D ZnO with cubic Cu2O nanoparticles. The photocatalytic activities of the composites were investigated for photodegradation of methylene blue solution as models’ pollutant under sunlight irradiation. The photocatalytic efficiency of a 0.1:1 mixture of Cu2O nanoparticles with 2D ZnO showed that the degradation rate was faster than those of individual ZnO nanocomposites and bulk nanoparticles, respectively. The photocatalytic degradation mechanism studied using specific radical scavengers corroborates the synergy between both semiconductors in the composite and evidences a Z-scheme mechanism to explain the electron transfer. The catalytic reuse tests show that the presence of the ZnO nanocomposite avoids the typical corrosion of Cu2O.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this research, we report a series of new heterostructured hybrid 2D ZnO nanocomposites sensitized with Cu2O nanoparticles for sunlight photocatalysis. The Cu2O nanoparticles were synthesized by a surfactant-free method and size reduced by a solvothermal method. 2D ZnO/Cu2O composites were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, reflectance diffuse spectroscopy and Fourier transform infrared. The results showed that the product is a material comprised of layered hybrid 2D ZnO with cubic Cu2O nanoparticles. The photocatalytic activities of the composites were investigated for photodegradation of methylene blue solution as models’ pollutant under sunlight irradiation. The photocatalytic efficiency of a 0.1:1 mixture of Cu2O nanoparticles with 2D ZnO showed that the degradation rate was faster than those of individual ZnO nanocomposites and bulk nanoparticles, respectively. The photocatalytic degradation mechanism studied using specific radical scavengers corroborates the synergy between both semiconductors in the composite and evidences a Z-scheme mechanism to explain the electron transfer. The catalytic reuse tests show that the presence of the ZnO nanocomposite avoids the typical corrosion of Cu2O. |
Arrau, S; Rodríguez-Díaz, M; Cassels, B K; Valenzuela-Barra, G; Delporte, C; Barriga, A; Miranda, H F Antihyperalgesic Activity of Quillaic Acid Obtained from Quillaja Saponaria Artículo de revista Mol. Curr. Top. Med. Chem., 19 (9), pp. 927-930, 2019. Resumen | Enlaces | BibTeX | Etiquetas: @article{RN11, title = {Antihyperalgesic Activity of Quillaic Acid Obtained from Quillaja Saponaria}, author = {S Arrau and M Rodr\'{i}guez-D\'{i}az and B K Cassels and G Valenzuela-Barra and C Delporte and A Barriga and H F Miranda}, url = {/brokenurl#<Go to ISI>://WOS:000295211000002}, doi = {https://doi.org/10.2174/1568026619666190509115741.}, year = {2019}, date = {2019-01-01}, journal = {Mol. Curr. Top. Med. Chem.}, volume = {19}, number = {9}, pages = {927-930}, abstract = {The strict application of IUPAC rules for the numbering of tropane alkaloids is not always applied by authors and there is hence a lot of confusion in the literature. In most cases, the notation of 3, 6/7-disubstituted derivatives has been chosen arbitrarily, based on NMR and MS data, without taking into account the absolute configuration of these two carbons. This paper discusses the problem and the relevance of CD and NMR to determine molecular configurations. We report on the use of H-1-NMR anisochrony (Delta delta) induced by the Mosher's chiral auxiliary reagents (R)-(-)- and (S)-(+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chlorides (MTPA-Cl), to determine the absolute configuration of (3R,6R)-3 alpha-hydroxy-6 beta-senecioyloxytropane, a disubstituted tropane alkaloid isolated from the aerial parts of Schizanthus grahamii (Solanaceae). These analytical tools should help future works in correctly assigning the configuration of additional 3, 6/7 disubstituted tropane derivatives.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The strict application of IUPAC rules for the numbering of tropane alkaloids is not always applied by authors and there is hence a lot of confusion in the literature. In most cases, the notation of 3, 6/7-disubstituted derivatives has been chosen arbitrarily, based on NMR and MS data, without taking into account the absolute configuration of these two carbons. This paper discusses the problem and the relevance of CD and NMR to determine molecular configurations. We report on the use of H-1-NMR anisochrony (Delta delta) induced by the Mosher's chiral auxiliary reagents (R)-(-)- and (S)-(+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chlorides (MTPA-Cl), to determine the absolute configuration of (3R,6R)-3 alpha-hydroxy-6 beta-senecioyloxytropane, a disubstituted tropane alkaloid isolated from the aerial parts of Schizanthus grahamii (Solanaceae). These analytical tools should help future works in correctly assigning the configuration of additional 3, 6/7 disubstituted tropane derivatives. |
Publicaciones 2011-2020
