Synthesis of New Isatin-3-[N2-(3-Arylideneamino-4-hydroxybenzoyl)]hydrazones as Antioxidant and Cytotoxic Agents

Abstract

In an effort to establish twenty five new isatin-3-[N²-(3- arylideneaimino-4-hydroxybenzoyl)]hydrazones (4a-y), isatin-3-[N²-(3-amino-4-hydroxybenzoyl)]hydrazones (3a-e) were condensed with five different aromatic aldehydes viz., benzaldehyde, 4-chlorobenzaldehyde, salicylaldehyde, anisaldehyde and veratraldehyde. The compounds, isatin-3-[N²-(3- amino-4-hydroxybenzoyl)]hydrazones (3a-e) were prepared from 3-amino-4-hydroxy benzoic acid hydrazide (2) by reacting with different isatins viz., isatin, 5 chloroisatin, 5-methylisatin, 5-bromoisatin and 5-flouroisatin in presence of ethanol. The compounds (4a-y) were screened for their in vitro antioxidant activity by 1,1-diphenyl-2-picrylhydrazil (DPPH) method and the cytotoxic activity by 3-(4,5-dimethyl thiazol-2,5-diphenyl)- tetrazolium bromide (MTT) assay method using HBL-100 cell lines and HeLa cell lines. All the 25 compounds showed antioxidant activity with IC₅₀ values in the range of 7.38 to 12.47 μM. Most significant of them was found to be the compound 4r (R = Br, R' = OH) showed highest percentage of free radical scavenging activity at 7.38 μM. Compound 4q (R = Br, R'' = Cl) was found to be relatively more cytotoxic agent against HeLa cell lines and HBL-100 cell lines with IC₅₀ values of 192.31 and 198.18 μM, respectively.