The purification and characterization of polysaccharides isolated from Ginkgo biloba and their in vitro antioxidant activities

Objective:To isolate and identify the polysaccharides of Ginkgo biloba and determine their antioxidant activities in vitro.Methods: Used hot extraction and alcohol precipitation to get the crude polysaccharides,removed protein with Sevag method,further purify by column chromatography packed with DEAE-52 and DEAE-Sepharose Fast Flow.The homogeneity and molecular weights were evaluated,configuration and monosaccharide composition were measured by IR and high performance ion chromatography analysis,the scavenging activities of GBPB-S on hydroxyl radical and DPPH were measured.Results: The molecular weights of GBPB-W and GBPB-S were 26 300 and 19 100,and both of them were composed of rhamnose,arabinose,galactose,glucose and mannose with the ratios of(3.48∶ 8.47∶ 3.73∶ 1.76∶ 1) and(5.34∶ 5.37∶ 5.27∶ 1∶ 1.68).GBPB-S had certain scavenging effect on hydroxyl radical and DPPH.Conclusion: The polysaccharide isolated from Ginkgo biloba has a direct antioxidant activities in vitro.