2018 |
Cassels, B K; Saez-Briones, P Dark Classics in Chemical Neuroscience: Mescaline Artículo de revista Acs Chemical Neuroscience, 9 (10), pp. 2448-2458, 2018, ISSN: 1948-7193. Resumen | Enlaces | BibTeX | Etiquetas: analogs, biosynthesis, cancer, derivatives, diethylamide, hallucinogen, hallucinogenic life-threatening lysergic-acid mescaline, metabolism, pedro, peyote, pharmacology, phenethylamine, phenyl-aethylamine, properties, relationships, san serotonin stimulus structure-activity synthesis, wachuma @article{RN389, title = {Dark Classics in Chemical Neuroscience: Mescaline}, author = { B.K. Cassels and P. Saez-Briones}, url = {/brokenurl#<Go to ISI>://WOS:000447954300015}, doi = {10.1021/acschemneuro.8b00215}, issn = {1948-7193}, year = {2018}, date = {2018-01-01}, journal = {Acs Chemical Neuroscience}, volume = {9}, number = {10}, pages = {2448-2458}, abstract = {Archeological studies in the United States, Mexico, and Peru suggest that mescaline, as a cactus constituent, has been used for more than 6000 years. Although it is a widespread cactus alkaloid, it is present in high concentrations in few species, notably the North American peyote (Lophophora williamsii) and the South American wachuma (Trichocereus pachanoi, T. peruvianus, and T. bridgesii). Spanish 16th century chroniclers considered these cacti "diabolic", leading to their prohibition, but their use persisted to our days and has been spreading for the last 150 years. In the late 1800s, peyote attracted scientific attention; mescaline was isolated, and its role in the psychedelic effects of peyote tops or "mescal buttons" was demonstrated. Its structure was established by synthesis in 1929, and alternative routes were developed, providing larger amounts for pharmacological and biosynthetic research. Although its effects are attributed mainly to its action as a 5-HT2A serotonin receptor agonist, mescaline binds in a similar concentration range to 5-HT1A and alpha(2A) receptors. It is largely excreted unchanged in human urine, and its metabolic products are apparently unrelated to its psychedelic properties. Its low potency is probably responsible for its relative neglect by recreational substance users, as the successful search for structure-activity relationships in the hallucinogen field focused largely on finding more potent analogues. Renewed interest in the possible therapeutic applications of psychedelic drugs may hopefully lead to novel insights regarding the commonalities and differences between the actions of individual classic hallucinogens.}, keywords = {analogs, biosynthesis, cancer, derivatives, diethylamide, hallucinogen, hallucinogenic life-threatening lysergic-acid mescaline, metabolism, pedro, peyote, pharmacology, phenethylamine, phenyl-aethylamine, properties, relationships, san serotonin stimulus structure-activity synthesis, wachuma}, pubstate = {published}, tppubtype = {article} } Archeological studies in the United States, Mexico, and Peru suggest that mescaline, as a cactus constituent, has been used for more than 6000 years. Although it is a widespread cactus alkaloid, it is present in high concentrations in few species, notably the North American peyote (Lophophora williamsii) and the South American wachuma (Trichocereus pachanoi, T. peruvianus, and T. bridgesii). Spanish 16th century chroniclers considered these cacti "diabolic", leading to their prohibition, but their use persisted to our days and has been spreading for the last 150 years. In the late 1800s, peyote attracted scientific attention; mescaline was isolated, and its role in the psychedelic effects of peyote tops or "mescal buttons" was demonstrated. Its structure was established by synthesis in 1929, and alternative routes were developed, providing larger amounts for pharmacological and biosynthetic research. Although its effects are attributed mainly to its action as a 5-HT2A serotonin receptor agonist, mescaline binds in a similar concentration range to 5-HT1A and alpha(2A) receptors. It is largely excreted unchanged in human urine, and its metabolic products are apparently unrelated to its psychedelic properties. Its low potency is probably responsible for its relative neglect by recreational substance users, as the successful search for structure-activity relationships in the hallucinogen field focused largely on finding more potent analogues. Renewed interest in the possible therapeutic applications of psychedelic drugs may hopefully lead to novel insights regarding the commonalities and differences between the actions of individual classic hallucinogens. |
Ardiles, A; Barrientos, R; Simirgiotis, M J; Borquez, J; Sepulveda, B; Areche, C Gastroprotective Activity of Parastrephia Quadrangularis (Meyen), Cabrera from the Atacama Desert Artículo de revista Molecules, 23 (9), 2018, ISSN: 1420-3049. Resumen | Enlaces | BibTeX | Etiquetas: clerodanes, derivatives, diterpenoids, endemic extracts, gastric gastroprotective, lc-ms/ms, lesions, medicine, mode, natural-products, plants, prostaglandins, rats tremetones, ulcer @article{RN379, title = {Gastroprotective Activity of Parastrephia Quadrangularis (Meyen), Cabrera from the Atacama Desert}, author = { A. Ardiles and R. Barrientos and M.J. Simirgiotis and J. Borquez and B. Sepulveda and C. Areche}, url = {/brokenurl#<Go to ISI>://WOS:000447365100272}, doi = {10.3390/molecules23092361}, issn = {1420-3049}, year = {2018}, date = {2018-01-01}, journal = {Molecules}, volume = {23}, number = {9}, abstract = {Forty-three metabolites including several methoxylated flavonoids, tremetones, and ent-clerodane diterpenes were accurately identified for the first time in the ethanolic extract of P. quadrangularis by means of hyphenated UHPLC-quadrupole Orbitrap mass spectrometry, and seven isolated compounds were tested regarding gastroprotective activity using the HCl/EtOH-induced lesion model in mice. A new tremetone (compound 6) is reported based on spectroscopic evidence. The isolated clerodanes and tremetones showed gastroprotective activity in a mouse model, evidenced by compound 7 (p-coumaroyloxytremetone), which showed the highest gastroprotective activity (76%), which was higher than the control drug lansoprazole (72%). Our findings revealed that several constituents of this plant have gastroprotective activity, and particularly, p-coumaroyloxytremetone could be considered as a lead molecule to explore new gastroprotective agents. This plant is a rich source of biologically active tremetones and terpenoids which can support the ethnobotanical use of the plant.}, keywords = {clerodanes, derivatives, diterpenoids, endemic extracts, gastric gastroprotective, lc-ms/ms, lesions, medicine, mode, natural-products, plants, prostaglandins, rats tremetones, ulcer}, pubstate = {published}, tppubtype = {article} } Forty-three metabolites including several methoxylated flavonoids, tremetones, and ent-clerodane diterpenes were accurately identified for the first time in the ethanolic extract of P. quadrangularis by means of hyphenated UHPLC-quadrupole Orbitrap mass spectrometry, and seven isolated compounds were tested regarding gastroprotective activity using the HCl/EtOH-induced lesion model in mice. A new tremetone (compound 6) is reported based on spectroscopic evidence. The isolated clerodanes and tremetones showed gastroprotective activity in a mouse model, evidenced by compound 7 (p-coumaroyloxytremetone), which showed the highest gastroprotective activity (76%), which was higher than the control drug lansoprazole (72%). Our findings revealed that several constituents of this plant have gastroprotective activity, and particularly, p-coumaroyloxytremetone could be considered as a lead molecule to explore new gastroprotective agents. This plant is a rich source of biologically active tremetones and terpenoids which can support the ethnobotanical use of the plant. |
Becerra-Ruiz, M; Vargas, V; Jara, P; Tirapegui, C; Carrasco, C; Nunez, M; Lezana, N; Galdámez, A; Vilches-Herrera, M Blue-Fluorescent Probes for Lipid Droplets Based on Dihydrochromeno-Fused Pyrazolo- and Pyrrolopyridines Artículo de revista European Journal of Organic Chemistry, 10.1002/ejoc.201701633 (34), pp. 4795-4801, 2018, ISSN: 1434-193x. Resumen | Enlaces | BibTeX | Etiquetas: derivatives, design, diels-alder dyes, fluorescent fused-ring heterocycles, lipids, nitrogen photophysics, probes, prodrugs, reactions, red solvent, systems @article{RN390, title = {Blue-Fluorescent Probes for Lipid Droplets Based on Dihydrochromeno-Fused Pyrazolo- and Pyrrolopyridines}, author = { M. Becerra-Ruiz and V. Vargas and P. Jara and C. Tirapegui and C. Carrasco and M. Nunez and N. Lezana and A. Gald\'{a}mez and M. Vilches-Herrera}, url = {/brokenurl#<Go to ISI>://WOS:000444540900018}, doi = {10.1002/ejoc.201701633}, issn = {1434-193x}, year = {2018}, date = {2018-01-01}, journal = {European Journal of Organic Chemistry}, volume = {10.1002/ejoc.201701633}, number = {34}, pages = {4795-4801}, abstract = {Lipid droplets (LDs) have been recognized as highly dynamic cellular organelles involved in important biological functions for the survival of organisms such as supplying food or energy. Nevertheless, lipid storage must be tightly controlled, because both its excess and the inability to store lipids can be detrimental to the organism, resulting in metabolic diseases or multifaceted systemic problems. Visualization and the monitoring of the concentration of LDs is essential to understanding these processes. Commercially available LD dyes, such as Nile Red and boron-dipyrromethene (BODIPY), offer several advantageous characteristics, but can be limiting in multicolor imaging because most ready-made fluorescent reporter constructs fluoresce in the green-to-red region of the visible spectrum. Nile Red emits between green and red, and BODIPY can be photoconverted from green to red fluorescence, limiting its ability to be utilized for time-lapse imaging of living cells. Here, we report the design and synthesis, the photophysical characterization, and biological testing of two easily prepared series of new blue-fluorescing dyes as markers for LDs. Confocal fluorescence microscopy results showed an interesting correlation between the chemical structures of these fluorescent probes and their specific staining patterns. The pyrazole-based compound 11c was found to be a specific dye for LDs, whereas the pyrrole-based compound 10d led to prominent staining of the membranous cell organelles.}, keywords = {derivatives, design, diels-alder dyes, fluorescent fused-ring heterocycles, lipids, nitrogen photophysics, probes, prodrugs, reactions, red solvent, systems}, pubstate = {published}, tppubtype = {article} } Lipid droplets (LDs) have been recognized as highly dynamic cellular organelles involved in important biological functions for the survival of organisms such as supplying food or energy. Nevertheless, lipid storage must be tightly controlled, because both its excess and the inability to store lipids can be detrimental to the organism, resulting in metabolic diseases or multifaceted systemic problems. Visualization and the monitoring of the concentration of LDs is essential to understanding these processes. Commercially available LD dyes, such as Nile Red and boron-dipyrromethene (BODIPY), offer several advantageous characteristics, but can be limiting in multicolor imaging because most ready-made fluorescent reporter constructs fluoresce in the green-to-red region of the visible spectrum. Nile Red emits between green and red, and BODIPY can be photoconverted from green to red fluorescence, limiting its ability to be utilized for time-lapse imaging of living cells. Here, we report the design and synthesis, the photophysical characterization, and biological testing of two easily prepared series of new blue-fluorescing dyes as markers for LDs. Confocal fluorescence microscopy results showed an interesting correlation between the chemical structures of these fluorescent probes and their specific staining patterns. The pyrazole-based compound 11c was found to be a specific dye for LDs, whereas the pyrrole-based compound 10d led to prominent staining of the membranous cell organelles. |
2017 |
Yempala, T; Cassels, B K Synthesis, Scope, H-1 and C-13 Spectral Assignments of Isomeric Dibenzofuran Carboxaldehydes Artículo de revista Research on Chemical Intermediates, 43 (3), pp. 1291-1299, 2017, ISSN: 0922-6168. Resumen | Enlaces | BibTeX | Etiquetas: beta-phenylethylamines bond c-13, copd, d]furan aldehyde and arylation, derivatives, design direct discovery, formation, h-1, inhibitors, nbome nmr, potential pulmonary-disease receptors, regioisomers, serotonin, treatment @article{RN345, title = {Synthesis, Scope, H-1 and C-13 Spectral Assignments of Isomeric Dibenzofuran Carboxaldehydes}, author = { T. Yempala and B.K. Cassels}, url = {/brokenurl#<Go to ISI>://WOS:000394374600002}, doi = {10.1007/s11164-016-2698-1}, issn = {0922-6168}, year = {2017}, date = {2017-01-01}, journal = {Research on Chemical Intermediates}, volume = {43}, number = {3}, pages = {1291-1299}, abstract = {Two isomeric dibenzofuran carboxaldehydes, namely 2-methoxydibenzo[b,d]furan-1-carbaldehyde (4) and 2-methoxydibenzo[b,d]furan-3-carbaldehyde (5), were synthesized. Formylation of 2-methoxydibenzo[b,d]furan (3) with alpha,alpha-dichloromethyl methyl ether and tin(IV) chloride gave a mixture of aldehydes 4 and 5 in 95 % yield and in a 35:65 ratio. Their H-1 and C-13 NMR spectral signals were not sufficiently resolved in CDCl3 solution to achieve their complete assignment, but this was possible in DMSO-d (6) with the help of 2D-NMR techniques: NOESY for H-1-H-1 interactions and HSQC and HMQC experiments for H-1-C-13 correlations. These aldehydes were used in the synthesis of novel beta-phenylethylamines and NBOMe derivatives, which are undergoing biological evaluation.}, keywords = {beta-phenylethylamines bond c-13, copd, d]furan aldehyde and arylation, derivatives, design direct discovery, formation, h-1, inhibitors, nbome nmr, potential pulmonary-disease receptors, regioisomers, serotonin, treatment}, pubstate = {published}, tppubtype = {article} } Two isomeric dibenzofuran carboxaldehydes, namely 2-methoxydibenzo[b,d]furan-1-carbaldehyde (4) and 2-methoxydibenzo[b,d]furan-3-carbaldehyde (5), were synthesized. Formylation of 2-methoxydibenzo[b,d]furan (3) with alpha,alpha-dichloromethyl methyl ether and tin(IV) chloride gave a mixture of aldehydes 4 and 5 in 95 % yield and in a 35:65 ratio. Their H-1 and C-13 NMR spectral signals were not sufficiently resolved in CDCl3 solution to achieve their complete assignment, but this was possible in DMSO-d (6) with the help of 2D-NMR techniques: NOESY for H-1-H-1 interactions and HSQC and HMQC experiments for H-1-C-13 correlations. These aldehydes were used in the synthesis of novel beta-phenylethylamines and NBOMe derivatives, which are undergoing biological evaluation. |
Martinez-Cifuentes, M; Weiss-Lopez, B; Araya-Maturana, R Theoretical Study About the Effect of Halogen Substitution on the Reactivity of Antitumor 3-Formylchromones and Their Free Radicals Artículo de revista Journal of Chemistry, 10.1155/2017/9254831 , 2017, ISSN: 2090-9063. Resumen | Enlaces | BibTeX | Etiquetas: activity, antidiabetic antioxidants, chromone, chromonyl-2, derivatives, flavonoids, in-vitro, inhibitors polyphenolic respiration, tumor-cell @article{RN373, title = {Theoretical Study About the Effect of Halogen Substitution on the Reactivity of Antitumor 3-Formylchromones and Their Free Radicals}, author = { M. Martinez-Cifuentes and B. Weiss-Lopez and R. Araya-Maturana}, url = {/brokenurl#<Go to ISI>://WOS:000396251800001}, doi = {10.1155/2017/9254831}, issn = {2090-9063}, year = {2017}, date = {2017-01-01}, journal = {Journal of Chemistry}, volume = {10.1155/2017/9254831}, abstract = {The mandatory presence of a chlorine atom on the aromatic ring of 6-hydroxy-3-formyl angular chromones, on the respiration inhibition of mammary carcinoma mouse, is explained through a computational study of these compounds. This study analyzes the reactivity of the neutral molecules and their free radicals, in gas phase and with water solvation, incorporated by the polarizable continuum medium (PCM) approach. Electrophilic reactivities were evaluated using Fukui (f(+)) and Parr (P+) functions. The stabilities of radical species formed by the abstraction of a hydrogen atom from the O-H bond were evaluated by bond dissociation enthalpy (BDE) and spin density (SD) calculations. This study has potential implications for the design of chromone analogues as anticancer compounds.}, keywords = {activity, antidiabetic antioxidants, chromone, chromonyl-2, derivatives, flavonoids, in-vitro, inhibitors polyphenolic respiration, tumor-cell}, pubstate = {published}, tppubtype = {article} } The mandatory presence of a chlorine atom on the aromatic ring of 6-hydroxy-3-formyl angular chromones, on the respiration inhibition of mammary carcinoma mouse, is explained through a computational study of these compounds. This study analyzes the reactivity of the neutral molecules and their free radicals, in gas phase and with water solvation, incorporated by the polarizable continuum medium (PCM) approach. Electrophilic reactivities were evaluated using Fukui (f(+)) and Parr (P+) functions. The stabilities of radical species formed by the abstraction of a hydrogen atom from the O-H bond were evaluated by bond dissociation enthalpy (BDE) and spin density (SD) calculations. This study has potential implications for the design of chromone analogues as anticancer compounds. |
2016 |
Lezana, N; Matus-Perez, M; Galdámez, A; Luhr, S; Vilches-Herrera, M Highly Stereoselective and Catalyst-Free Synthesis of Annulated Tetrahydropyridines by Intramolecular Imino-Diels-Alder Reaction under Microwave Irradiation in Water Artículo de revista Green Chemistry, 18 (13), pp. 3712-3717, 2016, ISSN: 1463-9262. Resumen | Enlaces | BibTeX | Etiquetas: derivatives, mechanism n-arylimines, one-pot @article{lezana2016highly, title = {Highly Stereoselective and Catalyst-Free Synthesis of Annulated Tetrahydropyridines by Intramolecular Imino-Diels-Alder Reaction under Microwave Irradiation in Water}, author = { N. Lezana and M. Matus-Perez and A. Gald\'{a}mez and S. Luhr and M. Vilches-Herrera}, url = {/brokenurl#<Go to ISI>://WOS:000378715700005}, doi = {10.1039/c6gc00912c}, issn = {1463-9262}, year = {2016}, date = {2016-01-01}, journal = {Green Chemistry}, volume = {18}, number = {13}, pages = {3712-3717}, abstract = {A microwave-assisted method for the synthesis of tetracyclic tetra-hydropyridines via an intramolecular imino-Diels-Alder reaction in water is reported. The reaction proceeds under catalyst-free conditions and shows excellent stereoselectivity.}, keywords = {derivatives, mechanism n-arylimines, one-pot}, pubstate = {published}, tppubtype = {article} } A microwave-assisted method for the synthesis of tetracyclic tetra-hydropyridines via an intramolecular imino-Diels-Alder reaction in water is reported. The reaction proceeds under catalyst-free conditions and shows excellent stereoselectivity. |
Yempala, T; Cassels, B K Simple and Efficient Synthesis of Various Dibenzofuran Carbaldehydes Artículo de revista Synthetic Communications, 46 (23), pp. 1909-1915, 2016, ISSN: 0039-7911. Resumen | Enlaces | BibTeX | Etiquetas: bond bromo carbaldehydes, cascade, derivatives, design, dibenzofuran efficient evaluation, formation, formylation, furans, methoxy phytoalexins, protocols, stems @article{RN292, title = {Simple and Efficient Synthesis of Various Dibenzofuran Carbaldehydes}, author = { T. Yempala and B.K. Cassels}, url = {/brokenurl#<Go to ISI>://WOS:000388722500006}, doi = {10.1080/00397911.2016.1235201}, issn = {0039-7911}, year = {2016}, date = {2016-01-01}, journal = {Synthetic Communications}, volume = {46}, number = {23}, pages = {1909-1915}, abstract = {We herein report simple and efficient methods for the synthesis of various formyl derivatives of dibenzofuran. The aldehydes reported are prepared in at most three steps and in yields greater than 60% from commercially available dibenzofuran, with one exception where isomers must be separated. The protocols described involve either formylation of previously functionalized dibenzofuran derivatives or the initial introduction of the formyl group and subsequent further functionalization under standard reaction conditions as described. We have also reported an efficient and simple method for the synthesis of keywords methoxydibenzofurans in high yield (65% overall for two steps}, keywords = {bond bromo carbaldehydes, cascade, derivatives, design, dibenzofuran efficient evaluation, formation, formylation, furans, methoxy phytoalexins, protocols, stems}, pubstate = {published}, tppubtype = {article} } We herein report simple and efficient methods for the synthesis of various formyl derivatives of dibenzofuran. The aldehydes reported are prepared in at most three steps and in yields greater than 60% from commercially available dibenzofuran, with one exception where isomers must be separated. The protocols described involve either formylation of previously functionalized dibenzofuran derivatives or the initial introduction of the formyl group and subsequent further functionalization under standard reaction conditions as described. We have also reported an efficient and simple method for the synthesis of keywords methoxydibenzofurans in high yield (65% overall for two steps |
Martinez-Cifuentes, M; Weiss-Lopez, B; Araya-Maturana, R A Computational Study of Structure and Reactivity of N-Substitued-4-Piperidones Curcumin Analogues and Their Radical Anions Artículo de revista Molecules, 21 (12), 2016, ISSN: 1420-3049. Resumen | Enlaces | BibTeX | Etiquetas: anion, anticancer, chemistry, computational curcumin, derivatives, in-vitro, indices, radical reactivity stability, targets @article{RN320, title = {A Computational Study of Structure and Reactivity of N-Substitued-4-Piperidones Curcumin Analogues and Their Radical Anions}, author = { M. Martinez-Cifuentes and B. Weiss-Lopez and R. Araya-Maturana}, url = {/brokenurl#<Go to ISI>://WOS:000392140100052}, doi = {10.3390/molecules21121658}, issn = {1420-3049}, year = {2016}, date = {2016-01-01}, journal = {Molecules}, volume = {21}, number = {12}, abstract = {In this work, a computational study of a series of N-substitued-4-piperidones curcumin analogues is presented. The molecular structure of the neutral molecules and their radical anions, as well as their reactivity, are investigated. N-substituents include methyl and benzyl groups, while substituents on the aromatic rings cover electron-donor and electron-acceptor groups. Substitutions at the nitrogen atom do not significantly affect the geometry and frontier molecular orbitals (FMO) energies of these molecules. On the other hand, substituents on the aromatic rings modify the distribution of FMO. In addition, they influence the capability of these molecules to attach an additional electron, which was studied through adiabatic (AEA) and vertical electron affinities (VEA), as well as vertical detachment energy (VDE). To study electrophilic properties of these structures, local reactivity indices, such as Fukui (f(+)) and Parr (P+) functions, were calculated, and show the influence of the aromatic rings substituents on the reactivity of alpha,beta-unsaturated ketones towards nucleophilic attack. This study has potential implications for the design of curcumin analogues based on a 4-piperidone core with desired reactivity.}, keywords = {anion, anticancer, chemistry, computational curcumin, derivatives, in-vitro, indices, radical reactivity stability, targets}, pubstate = {published}, tppubtype = {article} } In this work, a computational study of a series of N-substitued-4-piperidones curcumin analogues is presented. The molecular structure of the neutral molecules and their radical anions, as well as their reactivity, are investigated. N-substituents include methyl and benzyl groups, while substituents on the aromatic rings cover electron-donor and electron-acceptor groups. Substitutions at the nitrogen atom do not significantly affect the geometry and frontier molecular orbitals (FMO) energies of these molecules. On the other hand, substituents on the aromatic rings modify the distribution of FMO. In addition, they influence the capability of these molecules to attach an additional electron, which was studied through adiabatic (AEA) and vertical electron affinities (VEA), as well as vertical detachment energy (VDE). To study electrophilic properties of these structures, local reactivity indices, such as Fukui (f(+)) and Parr (P+) functions, were calculated, and show the influence of the aromatic rings substituents on the reactivity of alpha,beta-unsaturated ketones towards nucleophilic attack. This study has potential implications for the design of curcumin analogues based on a 4-piperidone core with desired reactivity. |
2015 |
Parra, T; Benites, J; Ruiz, L M; Sepulveda, B; Simirgiotis, M; Areche, C Gastroprotective Activity of Ent-Beyerene Derivatives in Mice: Effects on Gastric Secretion, Endogenous Prostaglandins and Non-Protein Sulfhydryls Artículo de revista Bioorganic & Medicinal Chemistry Letters, 25 (14), pp. 2813-2817, 2015, ISSN: 0960-894x. Resumen | Enlaces | BibTeX | Etiquetas: baccharis defense, derivatives, diterpenoids, ent-beyerene, gastric injury mucosal natural-products, semisynthetic tola, ulcer @article{RN236, title = {Gastroprotective Activity of Ent-Beyerene Derivatives in Mice: Effects on Gastric Secretion, Endogenous Prostaglandins and Non-Protein Sulfhydryls}, author = { T. Parra and J. Benites and L.M. Ruiz and B. Sepulveda and M. Simirgiotis and C. Areche}, url = {/brokenurl#<Go to ISI>://WOS:000355663100017}, doi = {10.1016/j.bmcl.2015.04.095}, issn = {0960-894x}, year = {2015}, date = {2015-01-01}, journal = {Bioorganic & Medicinal Chemistry Letters}, volume = {25}, number = {14}, pages = {2813-2817}, publisher = {2015 Elsevier Ltd.}, abstract = {Seventeen compounds (2-18) synthetized from the diterpenoid ent-beyer-15-en-18-ol (1) isolated from aerial part of Baccharis tola were tested for their gastroprotective activity on the model of HCl/EtOH-induced gastric lesions in mice. Furthermore cytotoxicity test toward fibroblasts and AGS cells were performed. The results showed that compound 1 (ED50 = 50 mg/kg), 2, 6 and 13 were the most active regarding gastroprotective activity. Compounds 8-10 and 17-18 showed the lowest cytotoxicity toward fibroblasts and AGS cells. Regarding to mode of gastroprotective action, the effect elicited by 6 (50 mg/kg) was reversed by Indomethacin but not by N-ethylmaleimide, NG-nitro-L-arginine methyl ester or ruthenium red, which suggests that prostaglandins are involved in the mode of gastroprotective action of 6.}, keywords = {baccharis defense, derivatives, diterpenoids, ent-beyerene, gastric injury mucosal natural-products, semisynthetic tola, ulcer}, pubstate = {published}, tppubtype = {article} } Seventeen compounds (2-18) synthetized from the diterpenoid ent-beyer-15-en-18-ol (1) isolated from aerial part of Baccharis tola were tested for their gastroprotective activity on the model of HCl/EtOH-induced gastric lesions in mice. Furthermore cytotoxicity test toward fibroblasts and AGS cells were performed. The results showed that compound 1 (ED50 = 50 mg/kg), 2, 6 and 13 were the most active regarding gastroprotective activity. Compounds 8-10 and 17-18 showed the lowest cytotoxicity toward fibroblasts and AGS cells. Regarding to mode of gastroprotective action, the effect elicited by 6 (50 mg/kg) was reversed by Indomethacin but not by N-ethylmaleimide, NG-nitro-L-arginine methyl ester or ruthenium red, which suggests that prostaglandins are involved in the mode of gastroprotective action of 6. |
Costantino, A R; Schneider, M G M; Galdamez, A; Ocampo, R A; Mandolesi, S D; Koll, L C The Synthesis of C-2 Symmetry Diesters of (3r,4r)-Ttfol through a Green and Stereoselective (2r,3r)-Taddol Rearrangement Artículo de revista Tetrahedron-Asymmetry, 26 (23), pp. 1341-1347, 2015, ISSN: 0957-4166. Resumen | Enlaces | BibTeX | Etiquetas: analogs, anhydrides carboxylic-acids, derivatives, esterification, esters, in-situ, inhibitors, integrase ligands, taddol @article{RN258, title = {The Synthesis of C-2 Symmetry Diesters of (3r,4r)-Ttfol through a Green and Stereoselective (2r,3r)-Taddol Rearrangement}, author = { A.R. Costantino and M.G.M. Schneider and A. Galdamez and R.A. Ocampo and S.D. Mandolesi and L.C. Koll}, url = {/brokenurl#<Go to ISI>://WOS:000366070000005}, doi = {10.1016/j.tetasy.2015.10.014}, issn = {0957-4166}, year = {2015}, date = {2015-01-01}, journal = {Tetrahedron-Asymmetry}, volume = {26}, number = {23}, pages = {1341-1347}, publisher = {2015 Elsevier Ltd.}, abstract = {An efficient, green, and atom economic methodology for the stereoselective synthesis of C-2 symmetry (3R,4R)-TTFOL diester derivatives has been developed. The procedure occurs through a (2R,3R)-TADDOL dioxolane cleavage and rearrangement under mild conditions by its reaction with a carboxylic acid in the presence of TFAA/H3PO4 without the need for an inert atmosphere to give generally high yields.}, keywords = {analogs, anhydrides carboxylic-acids, derivatives, esterification, esters, in-situ, inhibitors, integrase ligands, taddol}, pubstate = {published}, tppubtype = {article} } An efficient, green, and atom economic methodology for the stereoselective synthesis of C-2 symmetry (3R,4R)-TTFOL diester derivatives has been developed. The procedure occurs through a (2R,3R)-TADDOL dioxolane cleavage and rearrangement under mild conditions by its reaction with a carboxylic acid in the presence of TFAA/H3PO4 without the need for an inert atmosphere to give generally high yields. |
2014 |
Crespo, O; Diaz, C; O'dwyer, C; Gimeno, M C; Laguna, A; Ospino, I; Valenzuela, M L Luminescent Gold and Silver Complexes with the Monophosphane 1-(Pph2)-2-Me-C2b10h10 and Their Conversion to Gold Micro- and Superstructured Materials Artículo de revista Inorganic Chemistry, 53 (14), pp. 7260-7269, 2014, ISSN: 0020-1669. Resumen | Enlaces | BibTeX | Etiquetas: crystal-structures, derivatives, emitters, excited-state, ligands light-emitting-diodes, nido-carborane-diphosphine, o-carborane, oxidation, transition, triplet @article{RN202, title = {Luminescent Gold and Silver Complexes with the Monophosphane 1-(Pph2)-2-Me-C2b10h10 and Their Conversion to Gold Micro- and Superstructured Materials}, author = { O. Crespo and C. Diaz and C. O'dwyer and M.C. Gimeno and A. Laguna and I. Ospino and M.L. Valenzuela}, url = {/brokenurl#<Go to ISI>://WOS:000339472000027}, doi = {10.1021/ic5005424}, issn = {0020-1669}, year = {2014}, date = {2014-01-01}, journal = {Inorganic Chemistry}, volume = {53}, number = {14}, pages = {7260-7269}, abstract = {Gold and silver complexes containing the monophosphane 1-PPh2-2-Me-1,2-C2B10H10 with different coordination numbers (2, 3) have been synthesized: [M(7,8-(PPh2)(2)-C2B9H10)(1-PPh2-2-Me-C2B10H10)] (M = Ag, Au) and [Au-2(mu-1,n-C2B10H10)(1-PPh2-2-Me-C2B10H10)(2)] (n = 2, 12). Solid-state pyrolysis of [AuCl(1-PPh2-2-Me-C2B10H10)] and [Au-2(mu-1,12-C2B10H10)(1-PPh2-2-Me-C2B10H10)(2)] in air and of solutions of [AuCl(1-PPh2-2-Me-C2B10H10)] deposited on silicon and silica at 800 degrees C results in single-crystal Au, confirmed by diffraction and SEM-EDS. The morphology of the pyrolytic products depends on the thermolytic conditions, and different novel 3-D superstructures or microcrystals are possible. We also propose a mechanism for the thermal conversion of these precursors to structural crystalline and phase pure materials. The presence of the carborane monophosphane seems to originate quenching of the luminescence at room temperature in the complexes [Au-2(mu-1,n-C2B10H10)(1-PPh2-2-Me-C2B10H10)(2)], in comparison with other [Au-2(mu-1,n-C2B10H10)L-2] species (L = monophosphane).}, keywords = {crystal-structures, derivatives, emitters, excited-state, ligands light-emitting-diodes, nido-carborane-diphosphine, o-carborane, oxidation, transition, triplet}, pubstate = {published}, tppubtype = {article} } Gold and silver complexes containing the monophosphane 1-PPh2-2-Me-1,2-C2B10H10 with different coordination numbers (2, 3) have been synthesized: [M(7,8-(PPh2)(2)-C2B9H10)(1-PPh2-2-Me-C2B10H10)] (M = Ag, Au) and [Au-2(mu-1,n-C2B10H10)(1-PPh2-2-Me-C2B10H10)(2)] (n = 2, 12). Solid-state pyrolysis of [AuCl(1-PPh2-2-Me-C2B10H10)] and [Au-2(mu-1,12-C2B10H10)(1-PPh2-2-Me-C2B10H10)(2)] in air and of solutions of [AuCl(1-PPh2-2-Me-C2B10H10)] deposited on silicon and silica at 800 degrees C results in single-crystal Au, confirmed by diffraction and SEM-EDS. The morphology of the pyrolytic products depends on the thermolytic conditions, and different novel 3-D superstructures or microcrystals are possible. We also propose a mechanism for the thermal conversion of these precursors to structural crystalline and phase pure materials. The presence of the carborane monophosphane seems to originate quenching of the luminescence at room temperature in the complexes [Au-2(mu-1,n-C2B10H10)(1-PPh2-2-Me-C2B10H10)(2)], in comparison with other [Au-2(mu-1,n-C2B10H10)L-2] species (L = monophosphane). |
Martinez-Cifuentes, M; Weiss-Lopez, B; Santos, L S; Araya-Maturana, R Intramolecular Hydrogen Bond in Biologically Active O-Carbonyl Hydroquinones Artículo de revista Molecules, 19 (7), pp. 9354-9368, 2014, ISSN: 1420-3049. Resumen | Enlaces | BibTeX | Etiquetas: ab-initio, bond bond, chemistry, derivatives, dft, diels-alder electrostatic hydrogen hydroquinone, inhibitors, molecular molecules, natural orbital, potential, quinones, radicals reaction, resonance, respiration, tumor-cell @article{RN215, title = {Intramolecular Hydrogen Bond in Biologically Active O-Carbonyl Hydroquinones}, author = { M. Martinez-Cifuentes and B. Weiss-Lopez and L.S. Santos and R. Araya-Maturana}, url = {/brokenurl#<Go to ISI>://WOS:000340036200041}, doi = {10.3390/molecules19079354}, issn = {1420-3049}, year = {2014}, date = {2014-01-01}, journal = {Molecules}, volume = {19}, number = {7}, pages = {9354-9368}, abstract = {Intramolecular hydrogen bonds (IHBs) play a central role in the molecular structure, chemical reactivity and interactions of biologically active molecules. Here, we study the IHBs of seven related o-carbonyl hydroquinones and one structurally-related aromatic lactone, some of which have shown anticancer and antioxidant activity. Experimental NMR data were correlated with theoretical calculations at the DFT and ab initio levels. Natural bond orbital (NBO) and molecular electrostatic potential (MEP) calculations were used to study the electronic characteristics of these IHB. As expected, our results show that NBO calculations are better than MEP to describe the strength of the IHBs. NBO energies (Delta E-ij((2))) show that the main contributions to energy stabilization correspond to LP ->sigma* interactions for IHBs, (O1O2)-O-center dot center dot center dot-H-2 and the delocalization LP ->pi* for O-2-C-2 = C-alpha(beta). For the (O1O2)-O-center dot center dot center dot-H-2 interaction, the values of Delta E-ij((2)) can be attributed to the difference in the overlap ability between orbitals i and j (F-ij), instead of the energy difference between them. The large energy for the LP O-2 ->pi* C-2 = C-alpha(beta) interaction in the compounds 9-Hydroxy-5-oxo-4,8, 8-trimethyl-1, 9(8H)-anthracenecarbolactone (VIII) and 9,10-dihydroxy-4,4-dimethylanthracen-1(4H)-one (VII) (55.49 and 60.70 kcal/mol, respectively) when compared with the remaining molecules (all less than 50 kcal/mol), suggests that the IHBs in VIII and VII are strongly resonance assisted.}, keywords = {ab-initio, bond bond, chemistry, derivatives, dft, diels-alder electrostatic hydrogen hydroquinone, inhibitors, molecular molecules, natural orbital, potential, quinones, radicals reaction, resonance, respiration, tumor-cell}, pubstate = {published}, tppubtype = {article} } Intramolecular hydrogen bonds (IHBs) play a central role in the molecular structure, chemical reactivity and interactions of biologically active molecules. Here, we study the IHBs of seven related o-carbonyl hydroquinones and one structurally-related aromatic lactone, some of which have shown anticancer and antioxidant activity. Experimental NMR data were correlated with theoretical calculations at the DFT and ab initio levels. Natural bond orbital (NBO) and molecular electrostatic potential (MEP) calculations were used to study the electronic characteristics of these IHB. As expected, our results show that NBO calculations are better than MEP to describe the strength of the IHBs. NBO energies (Delta E-ij((2))) show that the main contributions to energy stabilization correspond to LP ->sigma* interactions for IHBs, (O1O2)-O-center dot center dot center dot-H-2 and the delocalization LP ->pi* for O-2-C-2 = C-alpha(beta). For the (O1O2)-O-center dot center dot center dot-H-2 interaction, the values of Delta E-ij((2)) can be attributed to the difference in the overlap ability between orbitals i and j (F-ij), instead of the energy difference between them. The large energy for the LP O-2 ->pi* C-2 = C-alpha(beta) interaction in the compounds 9-Hydroxy-5-oxo-4,8, 8-trimethyl-1, 9(8H)-anthracenecarbolactone (VIII) and 9,10-dihydroxy-4,4-dimethylanthracen-1(4H)-one (VII) (55.49 and 60.70 kcal/mol, respectively) when compared with the remaining molecules (all less than 50 kcal/mol), suggests that the IHBs in VIII and VII are strongly resonance assisted. |
Sotomayor-Zarate, R; Jara, P; Araos, P; Vinet, R; Quiroz, G; Renard, G M; Espinosa, P; Hurtado-Guzman, C; Moya, P R; Iturriaga-Vasquez, P; Gysling, K; Reyes-Parada, M Improving Amphetamine Therapeutic Selectivity: N,N-Dimethyl-Mta Has Dopaminergic Effects and Does Not Produce Aortic Contraction Artículo de revista Basic & Clinical Pharmacology & Toxicology, 114 (5), pp. 395-399, 2014, ISSN: 1742-7835. Resumen | Enlaces | BibTeX | Etiquetas: derivatives, dexamphetamine, dextroamphetamine, drugs, inhibitory lateral noradrenaline, oxidase properties, rat, release septum, transporters @article{RN197, title = {Improving Amphetamine Therapeutic Selectivity: N,N-Dimethyl-Mta Has Dopaminergic Effects and Does Not Produce Aortic Contraction}, author = { R. Sotomayor-Zarate and P. Jara and P. Araos and R. Vinet and G. Quiroz and G.M. Renard and P. Espinosa and C. Hurtado-Guzman and P.R. Moya and P. Iturriaga-Vasquez and K. Gysling and M. Reyes-Parada}, url = {/brokenurl#<Go to ISI>://WOS:000333969800004}, doi = {10.1111/bcpt.12168}, issn = {1742-7835}, year = {2014}, date = {2014-01-01}, journal = {Basic & Clinical Pharmacology & Toxicology}, volume = {114}, number = {5}, pages = {395-399}, abstract = {Amphetamine derivatives have therapeutic potential in diseases such as attention deficit hyperactivity disorder, narcolepsy and obesity. However, their prolonged use has been associated with cardiovascular toxicity and addiction. In recent years, we have studied the pharmacological effects of amphetamine derivatives such as methylthioamphetamine (MTA) and N,N-dimethyl-thioamphetamine, with the aim of improving their therapeutic selectivity. In this work, we show that similarly to MTA, N,N-dimethyl-thioamphetamine has effects on the dopamine system, producing a significant increase in extracellular levels of dopamine (as measured by in vivo brain microdialysis) and locomotor activity, which is a behavioural measure of dopaminergic activation. However, unlike MTA, N,N-dimethyl- thioamphetamine does not produce aortic contraction in vitro. Our results show that N,N-dimethyl-thioamphetamine is a drug that retains the dopaminergic effects of amphetamine derivatives but exhibits a lower potential for producing cardiovascular side effects.}, keywords = {derivatives, dexamphetamine, dextroamphetamine, drugs, inhibitory lateral noradrenaline, oxidase properties, rat, release septum, transporters}, pubstate = {published}, tppubtype = {article} } Amphetamine derivatives have therapeutic potential in diseases such as attention deficit hyperactivity disorder, narcolepsy and obesity. However, their prolonged use has been associated with cardiovascular toxicity and addiction. In recent years, we have studied the pharmacological effects of amphetamine derivatives such as methylthioamphetamine (MTA) and N,N-dimethyl-thioamphetamine, with the aim of improving their therapeutic selectivity. In this work, we show that similarly to MTA, N,N-dimethyl-thioamphetamine has effects on the dopamine system, producing a significant increase in extracellular levels of dopamine (as measured by in vivo brain microdialysis) and locomotor activity, which is a behavioural measure of dopaminergic activation. However, unlike MTA, N,N-dimethyl- thioamphetamine does not produce aortic contraction in vitro. Our results show that N,N-dimethyl-thioamphetamine is a drug that retains the dopaminergic effects of amphetamine derivatives but exhibits a lower potential for producing cardiovascular side effects. |
Bahamonde-Padilla, V E; Lopez-Cascales, J J; Araya-Maturana, R; Martinez-Cifuentes, M; Weiss-Lopez, B Thermodynamics and (Hnmr)-H-2 Study on the Insertion of Small Quinones into a Discotic Nematic Lyotropic Liquid Crystal Artículo de revista Chemphyschem, 15 (7), pp. 1422-1431, 2014, ISSN: 1439-4235. Resumen | Enlaces | BibTeX | Etiquetas: aqueous-solution, crystals, derivatives, dynamics, ewald, force-field, free-energy, lipid-bilayer, liquid membrane, mesh micelle microviscosity, molecular molecular-dynamics nmr particle quinones, resonance, simulations, spectroscopy @article{RN213, title = {Thermodynamics and (Hnmr)-H-2 Study on the Insertion of Small Quinones into a Discotic Nematic Lyotropic Liquid Crystal}, author = { V.E. Bahamonde-Padilla and J.J. Lopez-Cascales and R. Araya-Maturana and M. Martinez-Cifuentes and B. Weiss-Lopez}, url = {/brokenurl#<Go to ISI>://WOS:000335515900018}, doi = {10.1002/cphc.201301146}, issn = {1439-4235}, year = {2014}, date = {2014-01-01}, journal = {Chemphyschem}, volume = {15}, number = {7}, pages = {1422-1431}, abstract = {A detailed description of the distribution, interaction, and dynamics of molecules with biological activity dissolved in a hydrophobic bilayer, a simple model of a biological membrane, provides valuable information for a better understanding of drug functioning, which can be very useful in drug design. Here we present an H-2 NMR and molecular dynamics study on the insertion, distribution, interactions, and thermodynamics of two biologically active molecules, 9,10-dihydroxy-4,4-dimethyl-1,4,5,8-tetrahydroanthracen-1-one (HQ), with anticancer activity, and 4,4-dimethyl-1,4,5,8,9,10-hexahydroanthracen-1,9,10-trione (Q) a fungicide, dissolved in a nematic discotic lyotropic liquid crystal (ndllc) composed of sodium dodecylsulphate (SDS), decanol (DecOH) and Na2SO4 in water. H-2 NMR quadrupole splittings ((Q)) and longitudinal relaxation times (T-1) from HQ-d(6), Q-d(4), DecOH--d(2), partially deuterated water, and SDS-d(25) were measured and several molecular dynamics trajectories were also calculated. In particular, G, H, and S profiles for the process of both molecules crossing the bilayer were estimated. It was evidenced that the insertion of both molecules into the aggregate is a spontaneous process, and the molecules are mainly distributed in the internal side of the interface. Addition of HQ or Q decreased the mobility of all aggregate components, but this effect was more pronounced for HQ. The rotational correlation time of Q allowed an estimate of 5.3 cP for the microviscosity inside the ndllc aggregate, in the order of previously measured values in similar environments. Both guest molecules display similar free-energy profiles for the process of crossing the bilayer, with a calculated barrier height of 25 and 36 kJmol(-1) for HQ and Q, respectively.}, keywords = {aqueous-solution, crystals, derivatives, dynamics, ewald, force-field, free-energy, lipid-bilayer, liquid membrane, mesh micelle microviscosity, molecular molecular-dynamics nmr particle quinones, resonance, simulations, spectroscopy}, pubstate = {published}, tppubtype = {article} } A detailed description of the distribution, interaction, and dynamics of molecules with biological activity dissolved in a hydrophobic bilayer, a simple model of a biological membrane, provides valuable information for a better understanding of drug functioning, which can be very useful in drug design. Here we present an H-2 NMR and molecular dynamics study on the insertion, distribution, interactions, and thermodynamics of two biologically active molecules, 9,10-dihydroxy-4,4-dimethyl-1,4,5,8-tetrahydroanthracen-1-one (HQ), with anticancer activity, and 4,4-dimethyl-1,4,5,8,9,10-hexahydroanthracen-1,9,10-trione (Q) a fungicide, dissolved in a nematic discotic lyotropic liquid crystal (ndllc) composed of sodium dodecylsulphate (SDS), decanol (DecOH) and Na2SO4 in water. H-2 NMR quadrupole splittings ((Q)) and longitudinal relaxation times (T-1) from HQ-d(6), Q-d(4), DecOH--d(2), partially deuterated water, and SDS-d(25) were measured and several molecular dynamics trajectories were also calculated. In particular, G, H, and S profiles for the process of both molecules crossing the bilayer were estimated. It was evidenced that the insertion of both molecules into the aggregate is a spontaneous process, and the molecules are mainly distributed in the internal side of the interface. Addition of HQ or Q decreased the mobility of all aggregate components, but this effect was more pronounced for HQ. The rotational correlation time of Q allowed an estimate of 5.3 cP for the microviscosity inside the ndllc aggregate, in the order of previously measured values in similar environments. Both guest molecules display similar free-energy profiles for the process of crossing the bilayer, with a calculated barrier height of 25 and 36 kJmol(-1) for HQ and Q, respectively. |
Garcia-Beltran, O; Areche, C; Cassels, B K; Suarez, L E C Coumarins Isolated from Esenbeckia Alata (Rutaceae) Artículo de revista Biochemical Systematics and Ecology, 52 , pp. 38-40, 2014, ISSN: 0305-1978. Enlaces | BibTeX | Etiquetas: alata, alkaloids, argentine chemotaxonomy, constituents, derivatives, esenbeckia febrifuga, furocoumarins, grandiflora, limonoids, noncoding plants, regions, rutaceae, terpenes @article{RN184, title = {Coumarins Isolated from Esenbeckia Alata (Rutaceae)}, author = { O. Garcia-Beltran and C. Areche and B.K. Cassels and L.E.C. Suarez}, url = {/brokenurl#<Go to ISI>://WOS:000334138500008}, doi = {10.1016/j.bse.2013.12.011}, issn = {0305-1978}, year = {2014}, date = {2014-01-01}, journal = {Biochemical Systematics and Ecology}, volume = {52}, pages = {38-40}, keywords = {alata, alkaloids, argentine chemotaxonomy, constituents, derivatives, esenbeckia febrifuga, furocoumarins, grandiflora, limonoids, noncoding plants, regions, rutaceae, terpenes}, pubstate = {published}, tppubtype = {article} } |
Simirgiotis, M J; Vallejos, J; Areche, C; Sepulveda, B Concise and Straightforward Asymmetric Synthesis of a Cyclic Natural Hydroxy-Amino Acid Artículo de revista Molecules, 19 (12), pp. 19516-19531, 2014, ISSN: 1420-3049. Resumen | Enlaces | BibTeX | Etiquetas: amino analogs, derivatives, inhibitors, pipecolic piperidine, protease seeds synthesis, total @article{RN181, title = {Concise and Straightforward Asymmetric Synthesis of a Cyclic Natural Hydroxy-Amino Acid}, author = { M.J. Simirgiotis and J. Vallejos and C. Areche and B. Sepulveda}, url = {/brokenurl#<Go to ISI>://WOS:000346793200014}, doi = {10.3390/molecules191219516}, issn = {1420-3049}, year = {2014}, date = {2014-01-01}, journal = {Molecules}, volume = {19}, number = {12}, pages = {19516-19531}, abstract = {An enantioselective total synthesis of the natural amino acid (2S,4R,5R)-4,5-di-hydroxy-pipecolic acid starting from D-glucoheptono-1, 4-lactone is presented. The best sequence employed as a keywords step the intramolecular nucleophilic displacement by an amino function of a 6-O-p-toluene-sulphonyl derivative of a methyl D-arabino-hexonate and involved only 12 steps with an overall yield of 19%. The structures of the compounds synthesized were elucidated on the basis of comprehensive spectroscopic (NMR and MS) and computational analysis.}, keywords = {amino analogs, derivatives, inhibitors, pipecolic piperidine, protease seeds synthesis, total}, pubstate = {published}, tppubtype = {article} } An enantioselective total synthesis of the natural amino acid (2S,4R,5R)-4,5-di-hydroxy-pipecolic acid starting from D-glucoheptono-1, 4-lactone is presented. The best sequence employed as a keywords step the intramolecular nucleophilic displacement by an amino function of a 6-O-p-toluene-sulphonyl derivative of a methyl D-arabino-hexonate and involved only 12 steps with an overall yield of 19%. The structures of the compounds synthesized were elucidated on the basis of comprehensive spectroscopic (NMR and MS) and computational analysis. |
Sieveking, I; Thomas, P; Estevez, J C; Quinones, N; Cuellar, M A; Villena, J; Espinosa-Bustos, C; Fierro, A; Tapia, R A; Maya, J D; Lopez-Munoz, R; Cassels, B K; Estevez, R J; Salas, C O 2-Phenylaminonaphthoquinones and Related Compounds: Synthesis, Trypanocidal and Cytotoxic Activities Artículo de revista Bioorganic & Medicinal Chemistry, 22 (17), pp. 4609-4620, 2014, ISSN: 0968-0896. Resumen | Enlaces | BibTeX | Etiquetas: activity, antimalarial antineoplastic assay, benzocarbazolequinones, biological colorimetric cruzi, cytotoxicity, derivatives, electronic evaluation, general-route, properties, quinones, t. trypanosoma-cruzi @article{RN190, title = {2-Phenylaminonaphthoquinones and Related Compounds: Synthesis, Trypanocidal and Cytotoxic Activities}, author = { I. Sieveking and P. Thomas and J.C. Estevez and N. Quinones and M.A. Cuellar and J. Villena and C. Espinosa-Bustos and A. Fierro and R.A. Tapia and J.D. Maya and R. Lopez-Munoz and B.K. Cassels and R.J. Estevez and C.O. Salas}, url = {/brokenurl#<Go to ISI>://WOS:000341293300010}, doi = {10.1016/j.bmc.2014.07.030}, issn = {0968-0896}, year = {2014}, date = {2014-01-01}, journal = {Bioorganic & Medicinal Chemistry}, volume = {22}, number = {17}, pages = {4609-4620}, publisher = {2014 Elsevier Ltd.}, abstract = {A series of new 2-aminonaphthoquinones and related compounds were synthesized and evaluated in vitro as trypanocidal and cytotoxic agents. Some tested compounds inhibited epimastigote growth and trypomastigote viability. Several compounds showed similar or higher activity and selectivity as compared with current trypanocidal drug, nifurtimox. Compound 4l exhibit higher selectivity than nifurtimox against Trypanosoma cruzi in comparison with Vero cells. Some of the synthesized quinones were tested against cancer cells and normal fibroblasts, showing that certain chemical modifications on the naphthoquinone moiety induce and excellent increase the selectivity index of the cytotoxicity (4g and 10). The results presented here show that the anti-T. cruzi activity of 2-aminonaphthoquinones derivatives can be improved by the replacement of the benzene ring by a pyridine moiety. Interestingly, the presence of a chlorine atom at C-3 and a highly lipophilic alkyl group or aromatic ring are newly observed elements that should lead to the discovery of more selective cytotoxic and trypanocidal compounds.}, keywords = {activity, antimalarial antineoplastic assay, benzocarbazolequinones, biological colorimetric cruzi, cytotoxicity, derivatives, electronic evaluation, general-route, properties, quinones, t. trypanosoma-cruzi}, pubstate = {published}, tppubtype = {article} } A series of new 2-aminonaphthoquinones and related compounds were synthesized and evaluated in vitro as trypanocidal and cytotoxic agents. Some tested compounds inhibited epimastigote growth and trypomastigote viability. Several compounds showed similar or higher activity and selectivity as compared with current trypanocidal drug, nifurtimox. Compound 4l exhibit higher selectivity than nifurtimox against Trypanosoma cruzi in comparison with Vero cells. Some of the synthesized quinones were tested against cancer cells and normal fibroblasts, showing that certain chemical modifications on the naphthoquinone moiety induce and excellent increase the selectivity index of the cytotoxicity (4g and 10). The results presented here show that the anti-T. cruzi activity of 2-aminonaphthoquinones derivatives can be improved by the replacement of the benzene ring by a pyridine moiety. Interestingly, the presence of a chlorine atom at C-3 and a highly lipophilic alkyl group or aromatic ring are newly observed elements that should lead to the discovery of more selective cytotoxic and trypanocidal compounds. |
2013 |
Diaz, C; Valenzuela, M L; Caceres, S; Diaz, R; O'dwyer, C Solvent and Stabilizer Free Growth of Ag and Pd Nanoparticles Using Metallic Salts/Cyclotriphosphazenes Mixtures Artículo de revista Materials Chemistry and Physics, 143 (1), pp. 124-132, 2013, ISSN: 0254-0584. Resumen | Enlaces | BibTeX | Etiquetas: annealing, derivatives, electron gold, mechanical-behavior, metals, microscopy, nanoparticles, nanorods organometallic palladium polyphosphazenes, precursors, properties, pyrolysis, shape-controlled solid-state surface synthesis, thermolytic transformation @article{RN146, title = {Solvent and Stabilizer Free Growth of Ag and Pd Nanoparticles Using Metallic Salts/Cyclotriphosphazenes Mixtures}, author = { C. Diaz and M.L. Valenzuela and S. Caceres and R. Diaz and C. O'dwyer}, url = {/brokenurl#<Go to ISI>://WOS:000327684100017}, doi = {10.1016/j.matchemphys.2013.08.034}, issn = {0254-0584}, year = {2013}, date = {2013-01-01}, journal = {Materials Chemistry and Physics}, volume = {143}, number = {1}, pages = {124-132}, publisher = {2013 Elsevier B.V.}, abstract = {Cyclotriphosphazene is used as a sacrificial solid-state template to synthesize a range of Ag and Pd nanoparticles with diverse geometries by thermal treatment using MLn/N3P3(O2C12H8)(3) mixtures. The Pd and Ag nanoparticles are synthesized by solid-state pyrolysis of AgPPh3[CF3SO3]/N3P3(O2C12H8)(3) and PdCl2/N3P3(O2C12H8)(3) mixtures with molar relationships of 1:1, 1:5 and 1:10 respectively, in air and at 800 degrees C. The morphology of the as-prepared nanoparticles is found to depend on the molar ratio of the precursor mixture, the preparation method and of the nature of the metal. Ag and Pd, microcrystals were thermally grown on Si from the respective 1:1 precursors while that metal foams were grown from 1:5 ratios precursors on SiO2 wafers. High resolution transmission electron microscopy investigations reveal in most cases small crystals of Pd. HRSTEM measurements indicate that the formation of the Pd and Ag nanoparticles occurs through a phase demixing and dewetting mechanism. This approach has potential to be a useful and facile method to prepare metallic nanoparticles without requiring solutions or surfactants for application in electronic, catalytic and sensor materials and devices.}, keywords = {annealing, derivatives, electron gold, mechanical-behavior, metals, microscopy, nanoparticles, nanorods organometallic palladium polyphosphazenes, precursors, properties, pyrolysis, shape-controlled solid-state surface synthesis, thermolytic transformation}, pubstate = {published}, tppubtype = {article} } Cyclotriphosphazene is used as a sacrificial solid-state template to synthesize a range of Ag and Pd nanoparticles with diverse geometries by thermal treatment using MLn/N3P3(O2C12H8)(3) mixtures. The Pd and Ag nanoparticles are synthesized by solid-state pyrolysis of AgPPh3[CF3SO3]/N3P3(O2C12H8)(3) and PdCl2/N3P3(O2C12H8)(3) mixtures with molar relationships of 1:1, 1:5 and 1:10 respectively, in air and at 800 degrees C. The morphology of the as-prepared nanoparticles is found to depend on the molar ratio of the precursor mixture, the preparation method and of the nature of the metal. Ag and Pd, microcrystals were thermally grown on Si from the respective 1:1 precursors while that metal foams were grown from 1:5 ratios precursors on SiO2 wafers. High resolution transmission electron microscopy investigations reveal in most cases small crystals of Pd. HRSTEM measurements indicate that the formation of the Pd and Ag nanoparticles occurs through a phase demixing and dewetting mechanism. This approach has potential to be a useful and facile method to prepare metallic nanoparticles without requiring solutions or surfactants for application in electronic, catalytic and sensor materials and devices. |
Diaz, C; Valenzuela, M L; Bobadilla, D Bimetallic Au/Ag Metal Superstructures from Macromolecular Metal Complexes in Solid-State Artículo de revista Journal of the Chilean Chemical Society, 58 (4), pp. 1994-1997, 2013, ISSN: 0717-9707. Resumen | Enlaces | BibTeX | Etiquetas: and au complexes, derivatives, fabrication, gold, macromolecular metallic morphology, nanocrystals, nanoparticles, organometallic polyphosphazenes, precursors, pyrolysis pyrolysis, superstructures, thermolytic transformation @article{RN143, title = {Bimetallic Au/Ag Metal Superstructures from Macromolecular Metal Complexes in Solid-State}, author = { C. Diaz and M.L. Valenzuela and D. Bobadilla}, url = {/brokenurl#<Go to ISI>://WOS:000331238800015}, doi = {10.4067/S0717-97072013000400019}, issn = {0717-9707}, year = {2013}, date = {2013-01-01}, journal = {Journal of the Chilean Chemical Society}, volume = {58}, number = {4}, pages = {1994-1997}, abstract = {Novel bimetallic Au/Ag superstructures have been prepared from solid-state pyrolysis of the macromolecular complexes Chitosan( MLn/M'Ln)(n) y PSP-4-PVPx(MLn/M'Ln)(n) with MLn = AuCl3 and M'Ln = Ag(CF3SO3). The characterization was made from XRD (X-ray diffraction of powder), SEM and EDS analysis. Morphologies are influenced by both the nature of the polymer and the metal/polymer, molar ratio of the polymer precursor. EDS analysis suggests a core/shell Au/Ag structure for the materials. A probable mechanism of the formation of these superstructures is discussed. Although separated reports of metallic superstructures of Au or Ag have been recently described, the here reported are the first bimetallic Au/Ag.}, keywords = {and au complexes, derivatives, fabrication, gold, macromolecular metallic morphology, nanocrystals, nanoparticles, organometallic polyphosphazenes, precursors, pyrolysis pyrolysis, superstructures, thermolytic transformation}, pubstate = {published}, tppubtype = {article} } Novel bimetallic Au/Ag superstructures have been prepared from solid-state pyrolysis of the macromolecular complexes Chitosan( MLn/M'Ln)(n) y PSP-4-PVPx(MLn/M'Ln)(n) with MLn = AuCl3 and M'Ln = Ag(CF3SO3). The characterization was made from XRD (X-ray diffraction of powder), SEM and EDS analysis. Morphologies are influenced by both the nature of the polymer and the metal/polymer, molar ratio of the polymer precursor. EDS analysis suggests a core/shell Au/Ag structure for the materials. A probable mechanism of the formation of these superstructures is discussed. Although separated reports of metallic superstructures of Au or Ag have been recently described, the here reported are the first bimetallic Au/Ag. |
2012 |
Bahamonde-Padilla, V E; Martinez-Cifuentes, M; Munoz-Masson, D; Ruiz, A I; Ahumada, H; Araya-Maturana, R; Soto-Delgado, J; Weiss-Lopez, B Location, Orientation and Dynamics of Two Molecules with Mitochondrial Activity Dissolved in Anionic Lyomesophase. A H-2-Nmr and Md Study Artículo de revista Journal of the Chilean Chemical Society, 57 (3), pp. 1295-1300, 2012, ISSN: 0717-9707. Resumen | Enlaces | BibTeX | Etiquetas: antioxidant, derivatives, deuterium dipalmitoylphosphatidylcholine, hydration, hydroquinones, longitudinal lyomesophase, parathion, peptides, proteins quadrupole quinones, relaxation respiration, simulations, splitting, time, tumor-cell @article{RN100, title = {Location, Orientation and Dynamics of Two Molecules with Mitochondrial Activity Dissolved in Anionic Lyomesophase. A H-2-Nmr and Md Study}, author = { V.E. Bahamonde-Padilla and M. Martinez-Cifuentes and D. Munoz-Masson and A.I. Ruiz and H. Ahumada and R. Araya-Maturana and J. Soto-Delgado and B. Weiss-Lopez}, url = {/brokenurl#<Go to ISI>://WOS:000309315300021}, doi = {10.4067/S0717-97072012000300021}, issn = {0717-9707}, year = {2012}, date = {2012-01-01}, journal = {Journal of the Chilean Chemical Society}, volume = {57}, number = {3}, pages = {1295-1300}, abstract = {4,4-Dimethyl-5,8-dihydroanthracene-1,9,10(4H)-trione (Q1) and 9,10-Dihydroxy-4,4-dimethyl-5,8-dihydro-1 (4H)-anthracenone (Q2), two molecules that inhibit cancer cell respiration, were selectively deuterated and dissolved in an anionic discotic nematic lyotropic liquid crystal (dnllc) solution. The solution provides a magnetic field oriented anisotropic medium, where the location, average orientation and dynamics of Q(1) and Q(2) were examined by measuring H-2-NMR quadrupole splittings (Delta v(Q)) and H-2 longitudinal relaxation times (T-1). The NMR data shows that both molecules are strongly attached to the aggregate and, when dissolved, increase the alignment of the interface components with the magnetic field. However they present different average orientations. To assist with the interpretation of the experimental results, 300ns Molecular Dynamics (MD) trajectories of a bilayer model of the aggregate were calculated. The results show that both molecules spontaneously diffuse inside the bilayer, to locate in the limit between the hydrophobic core and the interface. The orientations of both molecules in the aggregate are determined by the formation of H-bonds with water.}, keywords = {antioxidant, derivatives, deuterium dipalmitoylphosphatidylcholine, hydration, hydroquinones, longitudinal lyomesophase, parathion, peptides, proteins quadrupole quinones, relaxation respiration, simulations, splitting, time, tumor-cell}, pubstate = {published}, tppubtype = {article} } 4,4-Dimethyl-5,8-dihydroanthracene-1,9,10(4H)-trione (Q1) and 9,10-Dihydroxy-4,4-dimethyl-5,8-dihydro-1 (4H)-anthracenone (Q2), two molecules that inhibit cancer cell respiration, were selectively deuterated and dissolved in an anionic discotic nematic lyotropic liquid crystal (dnllc) solution. The solution provides a magnetic field oriented anisotropic medium, where the location, average orientation and dynamics of Q(1) and Q(2) were examined by measuring H-2-NMR quadrupole splittings (Delta v(Q)) and H-2 longitudinal relaxation times (T-1). The NMR data shows that both molecules are strongly attached to the aggregate and, when dissolved, increase the alignment of the interface components with the magnetic field. However they present different average orientations. To assist with the interpretation of the experimental results, 300ns Molecular Dynamics (MD) trajectories of a bilayer model of the aggregate were calculated. The results show that both molecules spontaneously diffuse inside the bilayer, to locate in the limit between the hydrophobic core and the interface. The orientations of both molecules in the aggregate are determined by the formation of H-bonds with water. |
2011 |
Arrau, S; Delporte, C; Cartagena, C; Rodriguez-Diaz, M; González, P; Silva, X; Cassels, B K; Miranda, H F Antinociceptive Activity of Quillaja Saponaria Mol. Saponin Extract, Quillaic Acid and Derivatives in Mice Artículo de revista Journal of Ethnopharmacology, 133 (1), pp. 164-167, 2011, ISSN: 0378-8741. Resumen | Enlaces | BibTeX | Etiquetas: activity, analgesic assay, derivatives, drugs hot-plate models, pain, quillaic quillaja saponaria, tail-flick @article{RN4m, title = {Antinociceptive Activity of Quillaja Saponaria Mol. Saponin Extract, Quillaic Acid and Derivatives in Mice}, author = { S. Arrau and C. Delporte and C. Cartagena and M. Rodriguez-Diaz and P. Gonz\'{a}lez and X. Silva and B.K. Cassels and H.F. Miranda}, url = {/brokenurl#<Go to ISI>://WOS:000286854100023}, doi = {10.1016/j.jep.2010.09.016}, issn = {0378-8741}, year = {2011}, date = {2011-01-01}, journal = {Journal of Ethnopharmacology}, volume = {133}, number = {1}, pages = {164-167}, publisher = {2010 Elsevier Ireland Ltd.}, abstract = {Ethnopharmacological relevance: Quillaja saponaria bark contains a high percentage of triterpene saponins and has been used for centuries as a cleansing and analgesic agent in Chilean folk medicine., Aim of the study: The topical and systemic analgesic effects of a commercial partially purified saponin extract, 3 beta,16 alpha-dihydroxy-23-oxoolean-12-en-28-oic acid (quillaic acid), methyl 3 beta,16 alpha-dihydroxy-23-oxoolean-12-en-28-oate and methyl 4-nor-3,16-dioxoolean-12-en-28-oate., Materials and methods: The samples were assessed in mice using the topical tail-flick and i.p. hot-plate tests, respectively., Results: All the samples showed activity in both analgesic tests in a dose-dependent manner. The most active against tail flick test was commercial partially purified saponin extract (EC50 27.9 mg%, w/v) and more than the ibuprofen sodium. On hot-plate test, methyl 4-nor-3, 16-dioxoolean-12-en-28-oate was the most active (ED50 12.2 mg/kg) and more than the ibuprofen sodium., Conclusions: The results of the present study demonstrated that Quillaja saponaria saponins, quillaic acid, its methyl ester, and one of the oxidized derivatives of the latter, elicit dose-dependent antinociceptive effects in two murine thermal models.}, keywords = {activity, analgesic assay, derivatives, drugs hot-plate models, pain, quillaic quillaja saponaria, tail-flick}, pubstate = {published}, tppubtype = {article} } Ethnopharmacological relevance: Quillaja saponaria bark contains a high percentage of triterpene saponins and has been used for centuries as a cleansing and analgesic agent in Chilean folk medicine., Aim of the study: The topical and systemic analgesic effects of a commercial partially purified saponin extract, 3 beta,16 alpha-dihydroxy-23-oxoolean-12-en-28-oic acid (quillaic acid), methyl 3 beta,16 alpha-dihydroxy-23-oxoolean-12-en-28-oate and methyl 4-nor-3,16-dioxoolean-12-en-28-oate., Materials and methods: The samples were assessed in mice using the topical tail-flick and i.p. hot-plate tests, respectively., Results: All the samples showed activity in both analgesic tests in a dose-dependent manner. The most active against tail flick test was commercial partially purified saponin extract (EC50 27.9 mg%, w/v) and more than the ibuprofen sodium. On hot-plate test, methyl 4-nor-3, 16-dioxoolean-12-en-28-oate was the most active (ED50 12.2 mg/kg) and more than the ibuprofen sodium., Conclusions: The results of the present study demonstrated that Quillaja saponaria saponins, quillaic acid, its methyl ester, and one of the oxidized derivatives of the latter, elicit dose-dependent antinociceptive effects in two murine thermal models. |
Dobado, J A; Gomez-Tamayo, J C; Calvo-Flores, F G; Martinez-Garcia, H; Cardona, W; Weiss-Lopez, B; Ramirez-Rodriguez, O; Pessoa-Mahana, H; Araya-Maturana, R Nmr Assignment in Regioisomeric Hydroquinones Artículo de revista Magnetic Resonance in Chemistry, 49 (6), pp. 358-365, 2011, ISSN: 0749-1581. Resumen | Enlaces | BibTeX | Etiquetas: basis-sets, c-13 calculations, chemical-shifts, coupling-constants, derivatives, dft, diels-alder giao, h, h-1 hmbc, hmqc, hydroquinone, nmr, o3lyp, organic-molecules, reaction, respiration, sensitivity, spin theoretical tumor-cell @article{RN34e, title = {Nmr Assignment in Regioisomeric Hydroquinones}, author = { J.A. Dobado and J.C. Gomez-Tamayo and F.G. Calvo-Flores and H. Martinez-Garcia and W. Cardona and B. Weiss-Lopez and O. Ramirez-Rodriguez and H. Pessoa-Mahana and R. Araya-Maturana}, url = {/brokenurl#<Go to ISI>://WOS:000291114500009}, doi = {10.1002/mrc.2745}, issn = {0749-1581}, year = {2011}, date = {2011-01-01}, journal = {Magnetic Resonance in Chemistry}, volume = {49}, number = {6}, pages = {358-365}, publisher = {2011 John Wiley & Sons, Ltd.}, abstract = {A set of regioisomeric pairs of tricyclic hydroquinones, analogues of antitumor 9,10-dihydroxy-4,4-dimethyl-5,8dihydroanthracen- 1(4H)-one (1) and other derivatives, were synthesized and their regiochemistry and NMR spectra assigned by using 1H-detected one-bond(C-H) HMQC and long-range C-HHMBC, in good agreement with theoretical O3LYP/Alhrichs-pVTZ calculations. The 5-hydroxymethyl derivatives (11, 15, 19) showed a 3 integral H,H coupling constant of methylene protons evidencing the presence of a seven-membered intramolecular hydrogen bonded ring, not observed for the 8-hydroxymethyl isomers.}, keywords = {basis-sets, c-13 calculations, chemical-shifts, coupling-constants, derivatives, dft, diels-alder giao, h, h-1 hmbc, hmqc, hydroquinone, nmr, o3lyp, organic-molecules, reaction, respiration, sensitivity, spin theoretical tumor-cell}, pubstate = {published}, tppubtype = {article} } A set of regioisomeric pairs of tricyclic hydroquinones, analogues of antitumor 9,10-dihydroxy-4,4-dimethyl-5,8dihydroanthracen- 1(4H)-one (1) and other derivatives, were synthesized and their regiochemistry and NMR spectra assigned by using 1H-detected one-bond(C-H) HMQC and long-range C-HHMBC, in good agreement with theoretical O3LYP/Alhrichs-pVTZ calculations. The 5-hydroxymethyl derivatives (11, 15, 19) showed a 3 integral H,H coupling constant of methylene protons evidencing the presence of a seven-membered intramolecular hydrogen bonded ring, not observed for the 8-hydroxymethyl isomers. |
Galdámez, A; Gutierrez-Hernandez, M; Cassels, B K; Saez-Briones, P Crystal Structure of (1r,5s)-9-Nitro-1,2,3,4,5,6-Hexahydro-1,5-Methanopyrido[1,2-a][1,5] Diazocin-8-One (9-Nitrocytisine), C11h13o3n3 Artículo de revista Journal of the Chilean Chemical Society, 56 (1), pp. 595-597, 2011, ISSN: 0717-9324. Resumen | Enlaces | BibTeX | Etiquetas: agonists, alpha-4-beta-2, crystal cytisine cytisinoid, derivatives, design diffraction, halogenated hydrogen-bond, in-vivo, nicotinic patterns, smoking-cessation, structure, therapeutic-efficacy, x-ray @article{RN14g, title = {Crystal Structure of (1r,5s)-9-Nitro-1,2,3,4,5,6-Hexahydro-1,5-Methanopyrido[1,2-a][1,5] Diazocin-8-One (9-Nitrocytisine), C11h13o3n3}, author = {A. Gald\'{a}mez and M. Gutierrez-Hernandez and B.K. Cassels and P. Saez-Briones}, url = {/brokenurl#<Go to ISI>://WOS:000290700500016}, doi = {10.4067/S0717-97072011000100016}, issn = {0717-9324}, year = {2011}, date = {2011-01-01}, journal = {Journal of the Chilean Chemical Society}, volume = {56}, number = {1}, pages = {595-597}, abstract = {The title compound (1, trivial name: 9 (or 3)-nitrocytisine) crystallizes with two independent molecules in the asymmetric unit. In its structure two rings form a bispidine framework that is fused to a 3-nitro-2-pyridone group. The half-normal probability plot reveals that the two molecules do not show any significant geometrical differences, except in conformations of the nitro-group, which is involved in intermolecular interactions. The crystal packing structure of the title compound is described in terms of three-dimensional supramolecular arrays built up from chains of N-H center dot center dot center dot O (nitro-group), hydrogen bonds and weak intermolecular C-H center dot center dot center dot O=C interactions, with graph-set descriptors C-2(2)(6) and C-2(2)(10) motifs, which together result in R-4(4)(26) rings motifs. These chains are additionally stabilized by intermolecular NO2.pi interactions.}, keywords = {agonists, alpha-4-beta-2, crystal cytisine cytisinoid, derivatives, design diffraction, halogenated hydrogen-bond, in-vivo, nicotinic patterns, smoking-cessation, structure, therapeutic-efficacy, x-ray}, pubstate = {published}, tppubtype = {article} } The title compound (1, trivial name: 9 (or 3)-nitrocytisine) crystallizes with two independent molecules in the asymmetric unit. In its structure two rings form a bispidine framework that is fused to a 3-nitro-2-pyridone group. The half-normal probability plot reveals that the two molecules do not show any significant geometrical differences, except in conformations of the nitro-group, which is involved in intermolecular interactions. The crystal packing structure of the title compound is described in terms of three-dimensional supramolecular arrays built up from chains of N-H center dot center dot center dot O (nitro-group), hydrogen bonds and weak intermolecular C-H center dot center dot center dot O=C interactions, with graph-set descriptors C-2(2)(6) and C-2(2)(10) motifs, which together result in R-4(4)(26) rings motifs. These chains are additionally stabilized by intermolecular NO2.pi interactions. |
Diaz, C; Valenzuela, M L; Yutronic, N; Villalobos, V; Barrera, G Nanostructured Vox/Vo(Po4)(N) Using Solid-State Vanadium Containing Phosphazene Precursors: A Useful Potential Bi-Catalyst System Artículo de revista Journal of Cluster Science, 22 (4), pp. 693-704, 2011, ISSN: 1040-7278. Resumen | Enlaces | BibTeX | Etiquetas: autogenic cyclophosphazenes, derivatives, electrochemical elevated-temperature, gold, morphology, nanofibres nanoparticles, organometallic polyphosphazenes, pressure, properties, pyrolysis, template, vanadium @article{RN32i, title = {Nanostructured Vox/Vo(Po4)(N) Using Solid-State Vanadium Containing Phosphazene Precursors: A Useful Potential Bi-Catalyst System}, author = { C. Diaz and M.L. Valenzuela and N. Yutronic and V. Villalobos and G. Barrera}, url = {/brokenurl#<Go to ISI>://WOS:000297250000012}, doi = {10.1007/s10876-011-0415-1}, issn = {1040-7278}, year = {2011}, date = {2011-01-01}, journal = {Journal of Cluster Science}, volume = {22}, number = {4}, pages = {693-704}, abstract = {Pyrolysis of molecular precursors containing vanadium organometallic and cyclic phosphazene affords mixtures of nanostructured vanadium oxides and pyrophosphates. The products from the molecular precursor [N3P3(OC6H5)(5)OC5H4N center dot Cp2VCl][PF6], and of the mixtures Cp2VCl2/N3P3(OC6H4CHO)(6) and Cp2VCl2/[NP(O2C12H8)](3) in several relationships 1:1, 1:3, 1:5 and 1:10, pyrolyzed under air and at 400 A degrees C and 600 A degrees C, give mixtures mainly V2O5 and VO(PO3)(2). Varied morphologies depending on the molecular or mixture precursors and of the temperature used were observed. Nanowires with diameters of approximate 40 nm were observed for the 1:5 Cp2VCl2/[NP(O2C12H8)](3) mixture pyrolyzed at 400 A degrees C, while the same mixture pyrolyzed at 600 A degrees C, affords xerogels of V2O5. The products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), infra-red (IR) spectroscopy and X-ray diffraction (XRD). The preparation method constitutes a novel one-pot solid-state way to nanostructured materials with potential applications both in oxidative dehydrogenation of light hydrocarbons with V2O5, as well as alkenes oxidations with VO(PO3)(2).}, keywords = {autogenic cyclophosphazenes, derivatives, electrochemical elevated-temperature, gold, morphology, nanofibres nanoparticles, organometallic polyphosphazenes, pressure, properties, pyrolysis, template, vanadium}, pubstate = {published}, tppubtype = {article} } Pyrolysis of molecular precursors containing vanadium organometallic and cyclic phosphazene affords mixtures of nanostructured vanadium oxides and pyrophosphates. The products from the molecular precursor [N3P3(OC6H5)(5)OC5H4N center dot Cp2VCl][PF6], and of the mixtures Cp2VCl2/N3P3(OC6H4CHO)(6) and Cp2VCl2/[NP(O2C12H8)](3) in several relationships 1:1, 1:3, 1:5 and 1:10, pyrolyzed under air and at 400 A degrees C and 600 A degrees C, give mixtures mainly V2O5 and VO(PO3)(2). Varied morphologies depending on the molecular or mixture precursors and of the temperature used were observed. Nanowires with diameters of approximate 40 nm were observed for the 1:5 Cp2VCl2/[NP(O2C12H8)](3) mixture pyrolyzed at 400 A degrees C, while the same mixture pyrolyzed at 600 A degrees C, affords xerogels of V2O5. The products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), infra-red (IR) spectroscopy and X-ray diffraction (XRD). The preparation method constitutes a novel one-pot solid-state way to nanostructured materials with potential applications both in oxidative dehydrogenation of light hydrocarbons with V2O5, as well as alkenes oxidations with VO(PO3)(2). |
Publicaciones 2011-2020
