Investigation of the Antioxidant Activity of Alchornea laxiflora (Benth) and its Constituents

摘要

The antioxidant activity of the 50% aqueous ethanol leaf extract and solvent fractions of Alchonea laxiflora were evaluated using DPPH Spectrophotometric assay. The two fractions tested, ethyl acetate andn-butanol fractions exhibited a relatively high activity with EC of 12.97?0.30 ?g mLG and 24.34?0.33?g mLG , 50 respectively. The crude extract, exhibited the least activity (EC 106.74?0.29). All tested samples were however 50, less potent than ascorbic acid used as reference standard (EC 4.78?0.25). Bioassay guided fractionation of 50, the n-butanol fraction using a combination of Accelerated gradient Chromatography (AGC) and Sephadex LH-20 column chromatography led to the isolation of two flavonoids. These compounds were identified as taxifolin glycoside and quercetrin using spectroscopy techniques such as- MS, ?H and ??C NMR.