The Effect of Substituents and Functional Groups on Enhancing the Antioxidant Activity of Benzoin Derivatives

Abstract

2-phenyl hydrazine-1-hydroxy, 1-[2-chlorophenyl] -2-4’-methoxyphenyl] ethane and 2-oxime-1-hydroxy, 1-[2-chlorophenyl] -2-4’-methoxyphenyl] ethane derivatives of benzoin have been synthesized from 2’chloro-4-methoxy benzoin by addition reaction. Structural elucidation of the synthesized compounds was done by FT-IR, FT-NMR studies. The presence of electron-withdrawing and electron-donating groups enhanced the antioxidant activity which was analyzed by 2,2-diphenyl-1-picrylhydrazyl assay, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) scavenging assay, hydrogen peroxide radical scavenging assay, Ferric reducing antioxidant power assay methods. The effect of functional groups and substituents in the core structure was studied and was compared with its parent compound. In this manuscript, two derivatives of benzoin viz. 2-phenyl hydrazine-1-hydroxy, 1-[2-chlorophenyl] -2-[4’-methoxyphenyl] ethane and 2-oxime-1-hydroxy, 1-[2-chlorophenyl]-2-[4’-methoxyphenyl] ethane (HA) derivatives were synthesized by benzoin condensation and followed by addition reaction to find a potential anti-oxidant agent. Qualitative analyses were determined by FT-IR and FT-NMR studies. Anti-oxidant activities were tested by DPPH assay, ABTS assay, FRAP assay H2O2 methods From the obtained results it is confirmed that the effect of withdrawing and electron releasing groups as a substituent in the core structure of parent compounds enhances the activity of anti-oxidant. The role of substituents is discussed in detail. The results of the biochemical assay reveal that the synthesized compounds serve as good free radical inhibitors and scavengers which inhibit the oxidative reactions, are responsible for cell damage, food spoilage, etc. The promising anti-oxidant activities are because of the effective substituents which play a prominent role in the drug industries.