2017 |
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 |
Martinez-Cifuentes, M; Clavijo-Allancan, G; Zuniga-Hormazabal, P; Aranda, B; Barriga, A; Weiss-Lopez, B; Araya-Maturana, R Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of O-Carbonyl Carbazolequinone Derivatives Artículo de revista International Journal of Molecular Sciences, 17 (7), 2016, ISSN: 1422-0067. Resumen | Enlaces | BibTeX | Etiquetas: antitumor assignment, basicities, c-13 carbazole, chemistry complete derivatives, dft, gas-phase hydroquinone ionization, mass molecules, nmr-spectra, qcisd, quinones, respiration, spectrometry, tumor-cell @article{RN321, title = {Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of O-Carbonyl Carbazolequinone Derivatives}, author = { M. Martinez-Cifuentes and G. Clavijo-Allancan and P. Zuniga-Hormazabal and B. Aranda and A. Barriga and B. Weiss-Lopez and R. Araya-Maturana}, url = {/brokenurl#<Go to ISI>://WOS:000381500900086}, doi = {UNSP 1071, 10.3390/ijms17071071}, issn = {1422-0067}, year = {2016}, date = {2016-01-01}, journal = {International Journal of Molecular Sciences}, volume = {17}, number = {7}, abstract = {A series of a new type of tetracyclic carbazolequinones incorporating a carbonyl group at the ortho position relative to the quinone moiety was synthesized and analyzed by tandem electrospray ionization mass spectrometry (ESI/MS-MS), using Collision-Induced Dissociation (CID) to dissociate the protonated species. Theoretical parameters such as molecular electrostatic potential (MEP), local Fukui functions and local Parr function for electrophilic attack as well as proton affinity (PA) and gas phase basicity (GB), were used to explain the preferred protonation sites. Transition states of some main fragmentation routes were obtained and the energies calculated at density functional theory (DFT) B3LYP level were compared with the obtained by ab initio quadratic configuration interaction with single and double excitation (QCISD). The results are in accordance with the observed distribution of ions. The nature of the substituents in the aromatic ring has a notable impact on the fragmentation routes of the molecules.}, keywords = {antitumor assignment, basicities, c-13 carbazole, chemistry complete derivatives, dft, gas-phase hydroquinone ionization, mass molecules, nmr-spectra, qcisd, quinones, respiration, spectrometry, tumor-cell}, pubstate = {published}, tppubtype = {article} } A series of a new type of tetracyclic carbazolequinones incorporating a carbonyl group at the ortho position relative to the quinone moiety was synthesized and analyzed by tandem electrospray ionization mass spectrometry (ESI/MS-MS), using Collision-Induced Dissociation (CID) to dissociate the protonated species. Theoretical parameters such as molecular electrostatic potential (MEP), local Fukui functions and local Parr function for electrophilic attack as well as proton affinity (PA) and gas phase basicity (GB), were used to explain the preferred protonation sites. Transition states of some main fragmentation routes were obtained and the energies calculated at density functional theory (DFT) B3LYP level were compared with the obtained by ab initio quadratic configuration interaction with single and double excitation (QCISD). The results are in accordance with the observed distribution of ions. The nature of the substituents in the aromatic ring has a notable impact on the fragmentation routes of the molecules. |
2014 |
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. |
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. |
2017 |
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. |
2016 |
Protonation Sites, Tandem Mass Spectrometry and Computational Calculations of O-Carbonyl Carbazolequinone Derivatives Artículo de revista International Journal of Molecular Sciences, 17 (7), 2016, ISSN: 1422-0067. |
2014 |
Intramolecular Hydrogen Bond in Biologically Active O-Carbonyl Hydroquinones Artículo de revista Molecules, 19 (7), pp. 9354-9368, 2014, ISSN: 1420-3049. |
2012 |
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. |