Synthesis, antimicrobial and antioxidant evaluation, and molecular docking study of 4,5-disubstituted 1,2,4-triazole-3-thiones

Abstract

There is a growing need for new antibiotics and antifungal drugs to combat pathogenic bacteria and fungi. In order to develop potential antimicrobial agents, some 1,2,4-triazole-3-thiones were synthesized from the reaction of hydrazides with isothiocyanates under optimized conditions in deep eutectic solvent of potassium carbonate-glycerol (1:5 M ratio). Blocking properties of all products were assessed on a variety of Gram-positive and Gram-negative bacterial as well as fungal pathogens. Good to excellent inhibitory effects especially against fungi were observed with all synthesized compounds. 5-(4-Hydroxyphenyl)-4-(4-nitrophenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (3b) showed significant antioxidant activity according to the results obtained from 2,2-diphenyl-1-picrylhydrazylf (DPPH) free radical scavenging experiments. The possible interaction mechanism of synthetic triazoles with 1IYL enzyme on Aspergillus fumigatus was investigated by molecular docking method. A complete agreement was found between experimental data and theoretical calculations. Hydrogen bond acceptor strength of N-1 in 1,2,4-triazole rings was the main cause of the observed differences.