Synthesis, in vitro anticancer and antioxidant activity of thiadiazole substituted thiazolidin-4-ones

A series of novel 5-alkyl/aryl thiadiazole substituted thiazolidin-4-ones were synthesized by a two-step process. In the first step, 5-alkyl/aryl substituted 2-aminothiadiazoles were synthesized, which on reaction with substituted aromatic aldehydes and thioglycolic acid in the presence of dicyclohexylcarbodiimide afforded thiazolidin-4-ones. All the compounds were synthesized in fairly good yields and their structures were confirmed by spectral and physical data. The title compounds were screened for in vitro anti-proliferative activity on human breast adenocarcinoma cells (MCF-7) by MTT assay. Most of the derivatives showed an IC50 less than 150 mu mol L-1. Among the compounds tested, 2-(2-nitrophenyl)-3-(5-methyl-1,3,4-thiadiazol-2-yl)-thiazolidin-4-one (3f), 2-(3-fluorophenyl)-3-(5-methyl-1,3,4-thiadiazol-2-yl)-thiazolidin-4-one (3b), and 2-(4-chlorophenyl)-3-(5-methyl-1,3,4-thiadiazol-2-yl)-thiazolidin-4-one (3c) were found to be the most active derivatives with IC50 values of 46.34, 66.84, and 60.71 mu mol L-1, respectively. Antioxidant studies of all the synthesized compounds were carried out by diphenylpicrylhydrazyl (DPPH) assay. Among the compounds tested, 2-phenyl-3-(5-styryl-1,3,4-thiadiazol-2-yl)-thiazolidin-4-one (3s) elicited superior antioxidant activity with IC50 of 161.93 mu mol L-1.