Abstract: Using water extraction and alcohol precipitation,deproteinization with Sevage method to obtain Gymnopilus spectabilis crude polysaccharide.The crude polysaccharides were separated with DEAE-52 cellulose ion exchange chromatography.Three components (GSPS-I,GSPS-II and GSPS-III) were obtained,GSPS- II and GSPS- III were mainly studied.The polysaccharide contents of GSPS-II and GSPS-III were 84.12% and 80.35%,respectively.By scanning electron microscopy (SEM),it was found that GSPS-II presented hexahedral structure,GSPS-III showed a brick shaped irregular structure;The infrared spectroscopy (IR) and proton magnetic resonance spectroscopy (¹H NMR) analysis showed that GSPS-II and GSPS-III had carbohydrate absorption peak and had anomeric hydrogen with α- and β-glycosidic configuration;The antioxidant activity of GSPS-II and GSPS-III was evaluated by scavenging DPPH,superoxide anion radical and ABTS radical.The results showed that the two kinds of polysaccharides showed a certain scavenging effect on the free radicals tested in this experiment.In summary,the separation and purification of the group from G.spectabilis GSPS-II,GSPS-III had good antioxidant activity.  

Key words: Gymnopilus spectabilis polysaccharide, physicochemical property, free radicals, antioxidant activity