Synthesis and screening of biologically significant 5-hydroxy isatin derivatives for antioxidant activity.

In the present work, some new 5-Hydroxyindole 3-thiosemicarbazone 2-ones and 5-[2(3)-dialkylaminoalkoxy] Indole 3-hydrazone 2-ones were prepared from 5-hydroxy isatin. The structures of the products were characterized by IR, NMR, and MASS Spectral studies. All the compounds were examined for antioxidant activity by using 1,1-diphenyl-2-picryl-hydrazyl and hydrogen peroxide (H2O2), and the total antioxidant capacity by a phosphomolybdenum assay. In general, the derivatives were found to exhibit antioxidant activity. Further, the compounds with dialkyl amino alkoxy at the C5 position demonstrated significant antioxidant activity.