Antioxidant activity of extracts of mallotus philippinensis fruit and bark

Several extracts from Mallotus philippinensis fruits and bark were prepared and evaluated for their total antioxidant activity (TAA), antiradical activity against DPPH. (2,2-diphenyl-1-picrylhydrazyl radical) and reducing power. The total phenolics and tannin contents in extracts were determined. The extract of the bark showed the strongest antiradical activity and reduction power; its TAA was 5.27 mmol Trolox equivalents/g. The TAA of other extracts ranged from 0.05 to 1.79 mmol Trolox equivalents/g extract. The content of total phenolics in the bark extract was 541 mg/g. The content of tannins in MP-4, expressed as absorbance units per mg at 500 nm, was found to be 0.412. Several phenolic constituents in the extracts were detected by reverse-phase high-performance liquid chromatography using a gradient solvent system with UV-DAD detection. Acetone was a suitable solvent for extraction of natural antioxidants from M. philippinensis fruits.