Constituents and antioxidant activity of polysaccharides in Gynostemma

The polysaccharides from Gynostemma were extracted by water extraction and precipitating with alcohol, it was further isolated by the Sephadex G-200 gel column. The structure of polysaccharide was determined by HPLC. To research external antioxidant activity of polysaccharide from polysaccharide. To investigate the reducing power of polysaccharides, as well as the antioxidant activities of it were evaluated by scavenging·OH, DPPH and O2- . The results showed that Gynostemma polysaccharide was mainly composed of Mannose, rhamnose, galacturonic acid, glucose, galactose, xylose, arabinose, and Gynostemma polysaccharide had satisfactory free radical scavenging activity. When the concentration of polysaccharide was 0.5 mg/mL, the IC 50 values of scavenging activity on ·OH, DPPH and O2- radical were:0.101, 0.263, 0.886 mg/mL.