Gallic acid or 3,4,5-trihydroxybenzoic acid is a poly-hydroxyl compound with potential therapeutic effects in the treatment/management of oxidative stress implicated in cancers, cardiovascular and neurodegenerative diseases amongst many others. The identity, purity, integrity and suitability of the acid were ascertained and established prior to the preparation of derivatives. Furthermore, a simple titrimetric method for its assay was designed. The esterification and selective reduction of the acid led to two derivatives coded ME and MA whose identities have been established to be ethyl gallate and 3,4,5-trihydroxycyclohexylmethanol (possibly a new reduction derivative) respectively using the IR spectral technique. Gallic acid and MA demonstrated minimal antioxidant activity at IC50 of 0.76 and 0.89 µg mL-1, respectively. However, ME was remarkably active at 0.37 µg mL-1 which compare favourably with 0.34 µg mL-1 elicited by Vitamin C (a standard antioxidant drug). The obtained results indicate that esterification enhances the antioxidant activity of gallic acid.
Key words: Gallic acid; esterification; reduction; ethyl gallate; 3,4,5-trihydroxycyclohexyl methanol.