Abstract :
Thiazolidine-4-one and 1,3,4 oxadiazole derivatives are recognized to possess many biological activities as antimicrobial, antifungal, anti-inflammatory, and anticancer. This work included synthesis of new 1,3thiazolidine-4-one compounds 4(a-i) derived from tolfenamic acid by reaction of tolfenamic acid hydrazide-hydrazones 3(a-i) with mercaptoacetic. Synthesis of tolfenamic 1,3,4 oxadiazole-2-thion (5) and converted it into: thioether 6(a-c) and Mannich base 7(a-d) derivatives. The newly synthesized compounds were confirmed by available spectral methods: FT-IR, 1H NMR, and 13C NMR. The antibacterial activity for most synthesized compounds was evaluated against two pathogenic bacteria, E.coli and S.aureus. The compounds 5, 7a and 7b were showed promising activity against E. coli and S.aureus while 4a showed promising activity against S.aureus. Titled compounds were subjected to in-vitro antioxidant activity by scavenging activity on 2,2-diphenyl-1-bicrylhydrazyl(DPPH), where the 4d,4i,5,6a, and 6b derivatives showed high to moderate antioxidant activity at IC50= 0.144, 0.126, 0.112, 0.138, and 0.132 mM, respectively, compared with ascorbic acid as a reference. Molecular modeling studies were performed for the compounds that exhibited high antibacterial activity against the binding sites of the targeted proteins.
