Zeferino Gómez-Sandoval

Synthesis and in Vitro Antioxidant Activity Evaluation of 3-Carboxycoumarin Derivatives and QSAR Study of Their DPPH• Radical Scavenging Activity

The in vitro antioxidant activities of eight 3-carboxycoumarin derivatives were assayed by the quantitative 1,1-diphenyl-2-picrylhydrazil (DPPH•) radical scavenging activity method. 3-Acetyl-6-hydroxy-2H-1-benzopyran-2-one (C1) and ethyl 6-hydroxy-2-oxo-2H-1-benzopyran-3-carboxylate (C2) presented the best radical-scavenging activity. A quantitative structure-activity relationship (QSAR) study was performed and correlated with the experimental DPPH• scavenging data. We used structural, geometrical, topological and quantum-chemical descriptors selected with Genetic Algorithms in order to determine which of these parameters are responsible of the observed DPPH• radical scavenging activity. We constructed a back propagation neural network with the hydrophilic factor (Hy) descriptor to generate an adequate architecture of neurons for the system description. The mathematical model showed a multiple determination coefficient of 0.9196 and a root mean squared error of 0.0851. Our results shows that the presence of hydroxyl groups on the ring structure of 3-carboxy-coumarins are correlated with the observed DPPH• radical scavenging activity effects.

QSAR study of the DPPH· radical scavenging activity of coumarin derivatives and xanthine oxidase inhibition by molecular docking

AbstractA Quantitative Structure-Activity Relationship (QSAR) of coumarins by genetic algorithms employing physicochemical, topological, lipophilic and electronic descriptors was performed. We have used experimental antioxidant activities of specific coumarin derivatives against the DPPH· radical molecule. Molecular descriptors such as Randic Path/Walk, hydrophilic factor and chemical hardness were selected to propose a mathematical model. We obtained a linear correlation with R2 = 96.65 and QLOO2 = 93.14 values. The evaluation of the predictive ability of the model was performed by applying the QASYM2,

Evaluation of the antiradical activity of hyperjovinol-A utilizing donor-acceptor maps

\hat r^2

Shape entropy's response to molecular ionization.

and Δrm2 methods. Fukui functions were calculated here for coumarin derivatives in order to delve into the mechanics by which they work as primary antioxidants. We also investigated xanthine oxidase inhibition with these coumarins by molecular docking. Our results show that hydrophobic, electrostatic and hydrogen bond interactions are crucial in the inhibition of xanthine oxidase by coumarins.

Renin gene haplotype diversity and linkage disequilibrium in two Mexican and one German population samples

AbstractHyperjovinol-A ((2-methyl-1-(2,4,6-trihydroxy-3-(3-hydroxy-3,7-dimethyloct-6-enyl)phen yl)propan-1-one) is an acylated phloroglucinol isolated from Hypericum Jovis and exhibiting good antioxidant activity. The study investigates the compound’s antiradical ability on the basis of the electron-donor and electron-acceptor abilities of its conformers, deriving donor and acceptor indexes and mapping them in terms of donor-acceptor maps (DAM). The DAMs of vitamins C and E and of carotene astaxantine are used as comparison references. Calculations were performed at the DFT/BPW91/6-311+G(d,p) level, with optimizations on fully relaxed geometries to obtain the conformers of the neutral molecule in vacuo, and single point calculations to obtain the energies of the cationic and anionic species in vacuo and of the neutral, cationic, and anionic species in water, ethanol, and pentylethanoate. The calculations in solution utilized the polarizable continuum model (PCM). The results indicate that hyperjovinol-A may have better antiradical activity than vitamin C. This is in agreement with experimental results, showing that the antioxidant activity of hyperjovinol-A is comparable with that of the best drugs currently in clinical use. The activity is maintained in solution. The Fukui function f- was also calculated for all the conformers of hyperjovinol-A, to identify the regions of highest reactivity. FigureAntiradical activity of hyperjovinol-Aᅟ

Synthesis and Biological Screening of Silicon-Containing Ibuprofen Derivatives: A Study of Their NF-κβ Inhibitory Activity, Cytotoxicity, and Their Ability to Bind IKKβ

In this work we define a shape entropy by calculating the Shannon’s entropy of the shape function. This shape entropy and its linear response to the change in the total number of electrons of the molecule are explored as descriptors of bonding properties. Calculations on selected molecular systems were performed. According to these, shape entropy properly describes electron delocalization while its linear response to ionization predicts changes in bonding patterns. The derivative of the shape entropy proposed turned out to be fully determined by the shape function and the Fukui function.

Estudio de usabilidad de visualización molecular educativa en un teléfono inteligente

Introduction. Renin is the main rate-limiting enzyme in the renin—angiotensin—aldosterone system. Its gene, REN, is a candidate crucial factor in essential hypertension and cardiovascular disease. The aim of this study was to evaluate allele and haplotype distributions of REN polymorphisms, and to estimate normalised linkage disequilibrium (D’) in Mexican and German populations. Materials and methods. Four groups were studied for the REN single nucleotide polymorphisms (SNPs) 1205C>T, 1303G>A, and 10607G>A, in population samples of Mexican Mestizo (n = 86), Mexican Huichol (n = 49), German (n = 39), and individuals with hypertension diagnosis (n = 66). Polymorphisms were detected by PCR—RFLP. Genotype, allele and haplotype frequencies were estimated. Results. SNP 1205C>T and 10607G>A allele and genotype distribution showed inter-group differences. The 1205T and 10607A allele showed a significance difference in hypertensive population. Haplotype analysis also showed some inter-group differences, especially in 1205C-1303G-10607G, 1205C-1303G-10607A and 1205T-1303G-10607G haplotypes. The segregation analysis disclosed complete linkage disequilibrium between 1205 and 1303 loci. Conclusion. These results provide an example of genetic diversity in related populations and illustrate the convenience of increasing the number of loci in associative studies between diseases and candidate genes.

Silicon containing ibuprofen derivatives with antioxidant and anti-inflammatory activities: An in vivo and in silico study

The synthesis and characterisation of new silicon-containing amides and esters derived from ibuprofen is reported. These compounds were tested against nuclear transcription factor κβ (NF-κβ). Higher inhibition values than those of ibuprofen were achieved by the new amides 10a–10d; ester derivatives did not show inhibitory activity. The cytotoxicity of these new derivatives was screened; none of them displayed significant toxicity at the screened doses. A molecular docking calculation on IKKβ (an enzyme related to NF-κβ activation) was carried out and the results showed that the amides interact better than ibuprofen with key residues, which are important to the inhibition of IKKβ.

Exploring the Structure, Energetic, and Magnetic Properties of Neutral Small Lithium Clusters Doped with Yttrium: Supermagnetic Atom Research

Chemistry students have difficulty understanding molecular structures and their functions. To aide their comprehension, molecular visualization software has been developed to run on smart phones, but in order to positively influence learning it must have a high degree of usability (usability measures how software is used in terms of efficiency, efficacy and satisfaction). This paper describes a usability study of molecular visualization software running on a smart phone, where chemistry students analyzed molecular models. Results showed very good usability and 95% of students wanted to use it in further classes.

Synthesis of Novel Pyridinium Betaine Precursors from exo-Norbornene Dicarboximides

ABSTRACT There are many chronic diseases related with inflammation. The chronic inflammation can produce other problems as cancer. Therefore, it is necessary to design drugs with better anti‐inflammatory activity than those in the clinic. Likewise, these could be used in chronic treatments with minimum adverse effects. The amide or ester functionality in combination with the insertion of a silyl alkyl moiety is able to improve some drug properties. In this context, the evaluation of a group of silicon containing ibuprofen derivatives (SCIDs) as antioxidants and anti‐inflammatory agents is reported. Antioxidant activity was evaluated by the 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH‐), 2,2′‐Azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic) acid (ABTS•+) and the Fe(II) chelating ability methods. The anti‐inflammatory activity was determined by using the carrageenan induced rat paw edema. The gastrotoxic profile of the SCIDs that displayed significant anti‐inflammatory activity was determined by the indomethacin induced ulceration method. The SCIDs performed better than ibuprofen as chelating agents for Fe(II) and as scavengers for the free radicals DPPH• and ABTS•+. On the anti‐inflammatory test, compound 4a inhibited the edema up to 87%, while 4d & 10b achieved significant inflammation inhibition at a lower effective dose 50 (ED50) than ibuprofens. None of the SCIDs endowed with anti‐inflammatory activity, showed significant gastrotoxic effects with respect to those displayed by ibuprofen. Based on the experimental results and aided by the theoretical docking approach, it was possible to rationalize how the SCIDs may bind to cyclooxygenase isoforms and helped to explain their reduced gastrotoxicity. The evaluated effects were improved in SCIDs with respect to ibuprofen. Graphical abstract Figure. No Caption available.