Free radical scavenging ability of Ximenia americana L. stem bark and leaf extracts.

Phytochemical investigation of the ethanol extract of stem bark and leaves of Ximenia americana L. revealed the presence of epicatechin and quercetin, respectively. This is the first report of the occurrence of epicatechin in this genus. The extracts, fractions and isolated compounds of X. americana were subjected to an in vitro antioxidant activity assay by the DPPH method (2,2-diphenyl-1-picrylhydrazyl). The EC50 values were calculated and the results indicate that the ethyl acetate fractions of the stem bark and leaves have high antioxidant activity and a high content of total phenols. The high antioxidant activity of these fractions is justified by the presence of epicatechin and quercetin.