NEW PHOSPHORUS COMPOUNDS K[PCL3(X)] (X= SCN, CN): PREPARATION AND DFT AND SPECTROSCOPIC STUDIES

Indexación: Web of Science. Scielo.Two new phosphorus complexes, potassium trichlorothiocyanophosphate (III) (PTCTCP; K[PCl3(SCN)]) and potassium trichlorocyanophosphate (III) (PTCCP; K[PCl3(CN)]) were synthesized from the reaction of KSCN and KCN, respectively, with PC^. The chemical formulas and compositions of these compounds were determined by elemental analysis and spectroscopic methods, such as phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy (31P-NMR), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy and mass spectrophotometry. All of the theoretical calculations and determinations of the properties of these compounds were performed as part of the Amsterdam Density Functional (ADF) program. Excitation energies were assessed using time-dependent perturbation density functional theory (TD-DFT). In addition, the molecular geometry was optimized and the frequencies and excitation energies were calculated using standard Slater-type orbital (STO) basis sets with triple-zeta quality double plus polarization functions (TZ2P) for all of the atoms. The assignment of the principal transitions and total densities of state (TDOS) for orbital analysis were performed using the GaussSum 2.2 program.http://www.scielo.cl/pdf/jcchems/v61n1/art15.pd

Docking studies on novel analogs of quinolones against DNA gyrase of Escherichia coli

Context: Bacterial resistance to antibiotics is the inevitable consequence of the use of antimicrobial agents. Thus, quinolones are an important class of antibacterials; these agents generally consist of a 1-subtituted-1,4-dihydro-4-oxopyridine-3-carboxylic acid moiety combined with an aromatic or heteroaromatic ring fused at the 5- and 6-position. Aims: To determine the binding of quinolones to DNA gyrase of Escherichia coli. Methods: An analysis was performed using an in silico approach to determine, by docking calculations and energy descriptors, the conformer of 4‐oxo‐1,4‐dihydroquinoline skeleton that forms the most stable complex with DNA gyrase of E. coli. Results: The complex shows that the pose of the quinolones coincides with the amino acid residues Asp87, Thr88, Arg91 and Met92, which is expected to be critical in the binding of quinolones to DNA gyrase of E. coli. A series of quinolones were computationally designed, and the interactions between the quinolones and the amino acid residues of the DNA gyrase were calculated. Conclusions: Among the designed compounds, compounds 105 and 115 exhibit higher binding energy values and interact with amino acids Asp87, Thr88, Arg91 and Met92

Relationships between the structural characteristic of curcumins that affect cell proliferation of hepatocarcinoma cells

Relationships between the structural characteristic of curcumin and dimethoxycurcumin and their antitumoral activity were studied. Treatment of HepG2 cells for 24 h with the curcumin and dimethoxycurcumin resulted in apoptosis induction and dose-dependent inhibition of cell proliferation. The calculated docking and the DFT method, suggest a structure-activity relationship between the activities of dimethoxycurcumin and curcumin structure and the apoptosis in HepG2 cell

Structural Antitumoral Activity Relationships of Synthetic Chalcones

Relationships between the structural characteristic of synthetic chalcones and their antitumoral activity were studied. Treatment of HepG2 cells for 24 h with synthetic 2’-hydroxychalcones resulted in apoptosis induction and dose-dependent inhibition of cell proliferation. The calculated reactivity indexes and the adiabatic electron affinities using the DFT method including solvent effects, suggest a structure-activity relationship between the Chalcones structure and the apoptosis in HepG2 cells. The absence of methoxy substituents in the B ring of synthetic 2’-hydroxychalcones, showed the mayor structure-activity pattern along the series

A Theoretical Study of the Binding of [Re6Se8(OH)2(H2O)4] Rhenium Clusters to DNA Purine Base Guanine

Hexanuclear rhenium complexes are promising candidates for use as antitumor drugs. However, to date, there has been no investigation into the nature of their binding to DNA. In this study, density functional theory (DFT) was used to examine the binding of [Re6Se8(OH)2(H2O)4] to the DNA purine base guanine. The geometrical structures of cluster-guanine adducts in water were modeled at the zero order regular approximation (ZORA)-PW91 level. Calculating the bond energies allowed us to compare the cis and trans forms of the cluster, and a possible manners of interaction between [Re6Se8(OH)2(H2O)3] clusters and DNA was obtained and explained

Participatory Methodology, from Induction, for Academic and Socio-culturally Disadvantaged College Students

Mejorar el desempeño de estudiantes académicos y socioculturalmente desfavorecidos utilizando una estrategia de aprendizaje basada en un tutorial e-MEIK (modelo de evaluación integrado en el programa de Kinesiología), desde la inducción hasta la investigación, en un programa de pregrado (fisioterapia) en la Universidad Bernardo O’Higgins, una universidad socialmente inclusiva ubicada en Santiago de Chile. La estrategia de aprendizaje se enfoca en diferentes objetivos de investigación a desarrollar e implementar por parte de los estudiantes debido a los malos resultados académicos de los estudiantes de primer año. Este modelo, con 267 estudiantes participantes, utilizó la Investigación Basada en Problemas (PBI) donde cada grupo integró las materias que estudió con su realidad profesional en un ensayo final y un video. Resultados: Al comparar las tasas de aprobación de los estudiantes en cada año académico (2010-2012), hubo una mejora significativa (p < .001), que demostró que los estudiantes, con deficiencias educativas a nivel de ingreso a la universidad, pueden mejorar sus estrategias de aprendizaje y rendimiento académico. La estrategia de aprendizaje fomentó la motivación, logró metas específicas e impactó el desempeño de los estudiantes, así como el desarrollo de sus propias habilidades. También fue posible mejorar sus habilidades lectoras, manejo del tiempo, potencial creativo y espontaneidad para superar obstáculos.To improve the performance of academic and socio-culturally disadvantaged students using a learning strategy based on a mediated tutorial e-MEIK (evaluation model integrated into the Kinesiology program), from induction to research, in an undergraduate program (physical therapy) at Universidad Bernardo O’Higgins, a socially inclusive university located in Santiago de Chile. The learning strategy focuses on different research goals to be developed by students and was implemented due to the poor academic results of the first-year students. This model, with 267 student participants, used Problem-Based Investigation (PBI) where each group integrated the subjects they studied together with their professional reality into a final essay and a video. Comparing the students’ pass rates in each academic year (2010-2012) there was a significant improvement (p < .001) showing that students with educational deficiencies at the university entry level can improve their learning strategies and academic achievement. The learning strategy encouraged motivation, achieved specific goals, and impacted students’ performance as well as the development of their own abilities. It was also possible to improve their reading skills, time management, creative potential, and spontaneity to overcome obstacles

The characterization of anti-T. cruzi activity relationships between ferrocenyl, cyrhetrenyl complexes and ROS release

© 2016, Springer Science+Business Media New York.Trypanosoma cruzi (T. cruzi) is the parasite that causes Chagas disease. Nifurtimox is the most used drug against the T. cruzi, this drug increases intermediaries nitro group, being mainly responsible for the high toxicity component, for this reason it is important to study new organic compounds and thus improve therapeutic strategies against Chagas disease. The electronic effects of ferrocenyl and cyrhetrenyl fragments were investigated by DFT calculation. A close correlation was found between HOMO–LUMO gap of nitro radical NO2 − with the experimental reduction potential found for nitro group and IC50 of two forms the T. cruzi (epimastigote and trypomastigote). The IC50 on human hepatoma cells is higher for both compounds compared to IC50 demonstrated in the two forms the T. cruzi, and additionally show reactive oxygen species release. The information obtained in this paper could generate two new drugs with anti-T. cruzi activity, but