Synthesis and characterization of a cobalt(II) complex with 5-amino-1-tosyl-1h-1,2,4-triazole as a sulfonamide ligand: antibacterial and molecular docking studies

A new cobalt(II) complex, [Co(L)4Cl2]·2C9H10N4O2S (1), was prepared by reaction of CoCl2·6H2O with a sulfonamide, 5-amino-1-tosyl-1H-1,2,4-triazole (L), in double-distilled water and ethanol (1:1 v/v). The sulfonamide was characterized by elemental analysis, and infrared and 1H-NMR spectroscopy, while the Co(II) complex was characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction analysis. The X-ray structure analysis reveals that 1 consists of a mononuclear cobalt(II) complex, [Co(L)4Cl2], and two molecules of the co-crystallized ligand (5-amino-1-tosyl-1H-1,2,4-triazole). The cobalt(II) in 1 is coordinated by four triazole ligands and two chlorides in an octahedral environment. The antimicrobial activity and molecular docking of ligand and 1 were investigated. Antibacterial and antifungal activity studies of L and 1 show that both have moderate-to-significant activity against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria and fungi (Aspergillus niger and Candida albicans). According to molecular docking results, 1 could be a promising compound for developing antibacterial drugs. The docking results provide detailed evidence for the interactions of 1 with dihydropteroate synthase protein (DHPS). The microbial evaluation and molecular docking simulation results may lead to development of new drug candidates against bacterial and fungal strains.