Antioxidant activities of different fractions of polysaccharide purified from Gynostemma pentaphyllum Makino

The water-soluble crude polysaccharide GM, obtained from the Gynostemma pentaphyllum Makino by boiling-water extraction and ethanol precipitation, was fractionated by DEAE–Sepharose CL-6B column chromatography, and purified by Sephadex G-100 column chromatography, giving three polysaccharide fractions termed GMA, GMB and GMC. The monosaccharide components of them were studied by PC and GC. On the basis of superoxide radical assay, hydroxyl radical assay and self-oxidation of 1,2,3-phentriol assay, the antioxidant activities of GM, GMA, GMB and GMC were investigated. Among these contents, GMC had the higher scavenging effects on superoxide radicals and inhibitory effects on self-oxidation of 1,2,3-phentriol, and so should be explored as a novel potential antioxidant.