ABSTRACT
Antimicrobial screening of several novel 4-thiazolidinones with benzothiazole moiety has been performed. These compounds were evaluated for antimicrobial activity against a panel of bacterial and fungal strains. The strains were treated with these benzothiazole derivatives at varying concentrations, and MIC’s were calculated. Structures of these compounds have been determined by spectroscopic studies viz., FT-IR, 1H NMR, 13C NMR and elemental analysis. Significant antimicrobial activity was observed for some members of the series, and compounds viz. 3-(4-(benzo[d]thiazol-2-yl) phenyl)-2-(4-methoxyphenyl)thiazolidin-4-one and 3-(4-(benzo[d]thiazol-2-yl)phenyl)-2-(4-hydroxy phenyl)thiazolidin-4-one were found to be the most active against E.coli and C.albicans with MIC values in the range of 15.6–125 μg/ml. Preliminary study of the structure–activity relationship revealed that electron donating groups associated with thiazolidine bearing benzothiazole rings had a great effect on the antimicrobial activity of these compounds and contributes positively for the action. DNA cleavage experiments gave valuable hints with supporting evidence for describing the mechanism of action and hence showed a good correlation between their calculated MIC’s and its lethality.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antifungal Agents/chemical synthesis , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Benzothiazoles/chemical synthesis , Benzothiazoles/chemistry , Benzothiazoles/pharmacology , Candida/drug effects , DNA, Bacterial/drug effects , DNA, Circular/drug effects , Disk Diffusion Antimicrobial Tests , Drug Evaluation, Preclinical , Electrophoresis, Agar Gel , Free Radical Scavengers/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Microbial Sensitivity Tests , Molecular Structure , Thiazolidines/chemical synthesis , Thiazolidines/chemistry , Thiazolidines/pharmacologyABSTRACT
2-[3-chlorophenyl]-benzamide was condensed with hydrazine hydrochloride in presence of 10% NaOH to yield 1-[3-chlorophenyl]-4-amino pththalazine [I]. Seven new Schiff bases [II a-g] have been synthesized by the interaction of I with different aromatic aldehyde in dioxane. In final step II was condensed with thioglycolic acid in the presence of acetic acid to yield substituted-2-aryl-3-[4'[1"-3"'-chlorophenyl] phthalazine]]-4-thiazolidione. The synthesized compounds have been characterized by elemental analysis, IR, PMR and Mass spectral analysis and screened for antifungal and insecticidal activity