Kayim Pineda-Urbina

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,

Shape entropy's response to molecular ionization.

\hat r^2

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

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.

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

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.

Aminosilanes derived from 1H-benzimidazole-2(3H)-thione.

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.

Organotin(IV) compounds derived from ibuprofen and cinnamic acids, an alternative into design of anti-inflammatory by the cyclooxygenases (COX-1 and COX-2) pathway

Density functional theory calculations based on magnetic and energetic stability criteria were performed to study a series of yttrium-doped lithium neutral clusters. A relativistic approximation was employed to properly describe the energy and multiplicity of the given clusters’ fundamental states. The interaction of the 4d-Y atomic orbitals with the sp-Li states had an important role in the magnetic and energetic behavior of the selected systems. The spin density was concentrated over the yttrium atom regardless of the size of the cluster. Li7Y is a new stable superatom due to its enhanced magnetic properties.

In silico receptor-based drug design of X,Y-benzenesulfonamide derivatives as selective COX-2 inhibitors

In two trimethylsilyl-substituted 1H-benzimidazole-2(3H)-thiones, noncovalent C—H⋯π interactions between the centroid of the benzmidazole system and the SiMe3 groups form helicoidal arrangements in one, and dimerization results in the formation of (8) rings via N—H⋯S interactions, along with parallel π–π interactions between imidazole and benzene rings, in the second compound.