Synthesis, Biological Activity, and Molecular Docking Studies of Novel 5-Substituted-1,2,4-Triazole-3-thione Derivatives

Seven Schiff base compounds were synthesized via the nucleophilic condensation of 5-substituted-3-thione-1,2,4-triazole and 2,4,6-trimethyl benzaldehyde. All of the synthesized compounds (A1-A3 and B1-B4) were thoroughly characterized by using spectroscopic and physical analytical methods. The in vitro antifungal activities of the prepared compounds were studied, and results showed that A2, B1, B2, and B3 have good biological activity. Molecular docking was used to predict the binding modes of the ligands to 6CR2 protein, and the reasons behind the excellent activities of A2 and B2 were explored. Finally,the highest occupied molecular orbital, lowest unoccupied molecular orbital, and natural bonding orbital of the compounds were calculated by using density functional theory at the B3LYP/6-31G level.