Publicaciones 2011-2020

@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}
}

@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}
}

@article{RN192,
title = {Synthesis of Coumarin Derivatives as Fluorescent Probes for Membrane and Cell Dynamics Studies},
author = { O. Garcia-Beltran and O. Yanez and J. Caballero and A. Gald\'{a}mez and N. Mena and M. Nunez and B.K. Cassels},
url = {/brokenurl#<Go to ISI>://WOS:000335487400009},
doi = {10.1016/j.ejmech.2014.02.016},
issn = {0223-5234},
year = {2014},
date = {2014-01-01},
journal = {European Journal of Medicinal Chemistry},
volume = {76},
pages = {79-86},
publisher = {2014 Elsevier Masson SAS.},
abstract = {Three coumarin-derived fluorescent probes, 3-acetyl-7-[(6-bromohexyl)oxy]-2H-chromen-2-one (FM1), 7-[(6-bromohexyl)oxy]-4-methyl-2H-chromen-2-one (FM2) and ethyl 2-7-[(6-bromohexyl)oxy]-2-oxo-2H-chromen-4-ylacetate (FM3), are described, with their photophysical constants. The compounds were tested in preliminary studies employing epifluorescence microscopy demonstrating that they allow the imaging of human neuroblastoma SH-SY5Y cell membranes. The structure of FM3 was confirmed by X-ray crystallographic analysis. Molecular dynamics (MD) simulations were used to characterize the localization and interactions of the studied compounds with a lipid bilayer model of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC).},
keywords = {biological-membranes, carboxylic-acids, cell coumarins, crystal-structure, decarboxylation depth, dynamics, energy-transfer, hydrogen-bond, membranes, model, molecular molecular-dynamics, probes, proteins, resonance},
pubstate = {published},
tppubtype = {article}
}