Molecular orbital and topological electron density study of n → π* interactions: amides and thioamides cases.

The n → π* interactions were studied in amides and thioamides systems models, through the analysis of the electron density topology along with the Natural Bonding Orbital (NBO) approach. The effect of the dispersion terms was assessed using different DFT functionals. The NBO, independent gradient model (IGM), and the analysis of the reduced density gradient outcomes show that dispersion forces play a significant role in the strength of n → π* interactions.

Effect of extracts from several sponges of Yucatan Coast on and preliminary chemical investigation of the bioactive extract of () .

In this study, twenty-four organic extracts from six marine sponge species, collected at shallows of Yucatan, Mexico, were evaluated against trophozoites and Vero cells. The dichloromethane and hexane extracts of exhibited the highest antigiardiasic activity (IC = 1.00 and 2.

Cytotoxic and antiproliferative activity of thiazole derivatives of Ochraceolide A.

A series of 15 novel 1,3-thiazole amide derivatives of the pentacyclic triterpene Ochraceolide A () was synthesized, characterized, and evaluated against three human cancer cell lines (MCF-7, MDA-MB-231 and SiHa) and a normal cell line (Vero). Synthetic derivatives were obtained by acylation of the 2-aminothiazole triterpene , previously reported. Remarkably, the 5-nitrofuramide derivative () showed better cytotoxic and antiproliferative activity than compound and the other derivatives against the three cancer cell lines with CC and IC values of 1.

Anti-inflammatory effects of Chrysophyllum cainito fruit extract in lipopolysaccharide-stimulated mouse peritoneal macrophages.

The present paper sought to investigate the in vitro and in vivo anti-inflammatory effects of the methanolic extract (ME), hexane-ethyl acetate fraction E (FE) found in Chrysophyllum cainito fruits (CCF), as well the lupeol acetate (LA) obtained from FE on lipopolysaccharide (LPS)-stimulated mouse peritoneal macrophages. The macrophages were treated with ME, FE or LA at various concentrations and the viability of cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. Production of pro-inflammatory (IL-1β, IL-6, and TNF-α) and anti-inflammatory (IL-10) cytokines, as well as the nitric oxide (NO) and hydrogen peroxide (HO) levels was determined using macrophages treated with ME, FE or LA at various concentrations and stimulated with LPS as an in vitro model.

The origin of the regiospecificity of acrolein dimerization.

Acrolein dimerization is a intriguing case since the reaction does not occur to form the electronically preferred regioisomeric adduct. Various explanations have been suggested to rationalize this experimental regioselectivity, however, none of these arguments had been convincing enough. In this work, the hetero Diels-Alder acrolein dimerization was theoretically investigated using DFT and MP2 methods.