Evaluation of Antioxidant, Antimicrobial and Anticancer activity of Thiazole Tagged Isatin Hydrazones

Isatin and its derivatives is versatile lead molecule for potential bioactive agents and shows wide spectrum of activities. In this study, we evaluated antioxidant, antimicrobial and cytotoxic activity of isatin-3-[N2-(2-benzalaminothiazol-4-yl)] hydrazone derivatives using well defined models. Antioxidant activity of the isatin derivatives (Va-Vj) was evaluated by using the 1, 1-diphenyl-2-picryl hydrazine radicals scavenging assay. The antimicrobial activity is evaluated by cup plate method and anticancer activity is evaluated by MTT assay against HBL-100 & HeLa cell lines. Compound Vh (R = 5-Cl, R1 = OH & R2 = OCH3) showed good antioxidant activity with the IC50 of 8.09 M. In addition Ve and Vi have showned most active antibacterial activity against Bacillus subtilis, Staphylococcus aureus and Escherichia coli with a Zone of Inhibition (mm) 20, 16, 18 and 14, 12, 15 on respective organism at 100 g/disc. The compound Vi have produced a good antifungal activity against Aspergillus niger and Clostridium vericulata with the zone of inhibition values of 9 and 8 mm respectively. These isatin derivatives also among the test compounds, compound Vd (R = 5-Cl, R1 = OH & R2 = OCH3) and compound Vh (R = 5-Cl, R1 = OH & R2 = OCH3) have shown nearly equal cytotoxic activity with IC50 values of 246.53 mM and 247.29 mM against HBL-100 cell lines and HeLa cell lines respectively. From the results, isatin derivatives showed powerful antioxidant activity, antimicrobial and anticancer activity may be due to the halogens substituted at 5th position of isatin. The standard drugs used were ampicillin, clotrimazole, cisplatin and ascorbic acid for antibacterial, antifungal, anticancer and antioxidant respectively.