BIO-GUIDED ISOLATION AND STRUCTURE ELUCIDATION OF ANTIOXIDANT COMPOUNDS FROM THE LEAVES OF FICUS SYCOMORUS

Abstract

Summary This study was performed to investigate the antioxidant activity of the defatted 70% methanol extract of Ficus sycomorus leaves using DPPH radical scavenging assay-guided isolation. This extract was fractionated using CHCl3, EtOAc and nBuOH. The results revealed that EtOAc and n-BuOH have strong DPPH radical scavenging (SC50 =13.48 and 8.47 µg/ml). Therefore, each EtOAc and n-BuOH was subjected to chromatographic separation and purification. Four compounds were isolated from EtOAc fraction (1-4) and three compounds from n-BuOH (5-7). The structures of the isolated compounds were elucidated using certain spectroscopic methods as quercetin (1) gallic acid (2) quercetin 3-O-L-rhamnopyranosyl(1→6)-β-D-glucopyranoside (Rutin) (3) ,quercetin 3-O-β-Dglucopyranoside (Isoquercitrin) (4), quercetin 3,7-O-α-L-dirhamnoside (5), quercetin 3-O-β-D-galactopyranosyl(1→6)-glucopyranoside (6) and β-sitosterol-3-β-Dglucopyranoside (7). Compounds (1-6) were found as major components and principally responsible for the antioxidant activity of F.sycomorus by using two in vitro methods, DPPH radical and total antioxidant capacity respectively. This is the first report on the antioxidant activity of the chemical constituents of F.sycomorus.