Synthesis of novel amides with antiradical capacity from 2-mercaptobenzimidazole and cinnamic acids: Evaluation through donor-acceptor maps and QSAR

Abstract

Abstract The structures of thioethers I-III and the new amidic compounds 1(a-f)-3(a-f) derived from 2-mercaptobenzimidazole (MBZ) and cinnamic acids were confirmed by NMR and elemental analysis. Antioxidant activity was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH●) radical scavenging assay and 2,2-azinobis (3-ethyl benzothiazoline-6-sulfonic acid) ABTS●+ radical cation decolorization method. Besides, donor-acceptor maps (DAM) and electrophilicity were calculated using DFT/B3LYP method with a 6-311G(d,p) basis set. MBZ, I-III and (1a-3a) compounds showed higher activity in in vitro antioxidant assays, confirming with in silico studies that they are the best candidates. The findings found in antiradical activity suggest that these compounds could be promising in the development of new antitumor and antimicrobial agents. QSAR Molecular properties and topological descriptors of the synthesized compounds 1(a-f)-3(a-f) were calculated. The QSAR model indicates that the size and molecular shape are relevant for the antiradical activity for this family of compounds.