Abstract: Crude Chaenomeles cathayensis polysaccharides (CCCPs) were isolated with hot water extraction followed by ethanol precipitation.The fine C.cathayensis polysaccharides (FCCPs) were obtained by deproteinization,decolorization and dialysis.FCCPs were further separated to afford a main fraction CCP₁ by anion exchange column chromatography on DEAE-cellulose and Sepharose CL-6B gel filtration column chromatography.The composition of CCP₁ was determined to be rhamnose,arabinose,fructose,mannitose,glucose in a molar ratio of 0.034:0.228:0.045:0.055:0.638 using high performance liquid chromatography (HPLC).The antioxidant activity assay revealed that C.cathayensis polysaccharides with different purity showed different antioxidant activities.The antioxidant activities of C.cathayensis polysaccharides increased with the increasing of the concentrations of polysaccharides.The results showed that CCCPs had higher scavenging efficiency on hydroxyl radical (·OH) and superoxide anion free radical (O₂^-·) than FCCPs and CCP₁.

Key words: Chaenomeles cathayensis, polysaccharide, separation, purification, antioxidant activity