Characterization of a novel polysaccharide isolated from Phyllanthus emblica L. and analysis of its antioxidant activities

Phyllanthus emblica L. is a tropical deciduous tree producing edible berries with potential medicinal value. In this study, a novel water-soluble phyllanthus emblica polysaccharide (PEP) from the berries was isolated by precipitation and purification, and analyzed for its structure features. The results showed that PEP was a alpha-pyran acidic heteropolysaccharide with a molecular weight of 1.31 x 10(5) Da, which included galacturonic acid, galactose, rhamnose, and arabinose with a molar ratio of 3.21:6.59:1:0.23. Furthermore, the antioxidant activities of PEP were determined and showed remarkable antioxidant capacities in DPPH, superoxide anion- and hydroxyl-radical scavenging, ferric-reducing antioxidant power, and lipid peroxidation inhibition. This work indicated that PEP as a natural antioxidant agent from the berries of Phyllanthus emblica L. had potential application for developing valuable nutraceutical in food industry.