Anti-oxidant and Anti-microbial activities of 2' ’, 4''-thiazolidindione derivatives of 7-flavonols

Objective: The synthesized compounds of 2' ’, 4''-thiazolidindione derivatives of 7-flavonols*, after characterization, aimed to be tested for their anti-oxidant and anti-microbial effects. Methods: i) Free radical scavenging actions tested by hydrogen peroxide-nitric oxide-and by alkaline DMSO-methods and ii) anti-microbial effects against various bacterial pathogens and against candida albicans by disc diffusion method. Results: Data were found to be dose dependent and IC₅₀ value was 30–60 μg/ml and the results revealed that the dinitro-, trinitro-and acetyl, dinitro derivatives showed better and/or equipotent activity to that of the standard, ascorbic acid. The synthesized compounds exerted variable inhibitory activities at a concentration of 1μg/10μl/disc with inhibition zone ranging from 7–26 mm in diameter and a good antifungal activity against Candida albicans at the concentration of (1μg/10μl/disc) with inhibition of 10–24 mm. Klebsiella tribatta are more susceptible to the action of the formylated samples, giving high inhibition values comparing to the other organisms. Compounds Ie and Ih resulted to a higher activity index (AI>1); compounds Id, Ig and Ii showed an equal value (AI=1); whereas, Ia, Ib, Ic and If showed only a moderate activity (AI<1) compared to the standard, Amikacin. Conclusion: The findings confirmed that the synthetic compounds of 3-formyl, 7-flavonol derivatives have significant anti-oxidant and anti-microbial activities.