Purification, characterization and in vitro antioxidant activities of polysaccharide from Chaenomeles speciosa

A water-soluble polysaccharide named as CSP-2 was isolated and purified from Chaenomeles speciosa by DEAE-Sepharose and Sephadex G-100 column chromatography. CSP-2 was composed of galactose (Gal), rhamnose (Rha), glucose (Glc) and xylose (Xyl) with a relative molar ratio of 3.8:1.6:1.2:0.4. The average molecular weight of CSP-2 was estimated to be about 4.6×10⁴Da. The in vitro antioxidant assay showed that CSP-2 exhibited remarkable antioxidant activities to scavenge the DPPH radical, superoxide radical, hydroxyl radical and ABTS radical and significant cytoprotective effects on H₂O₂-induced PC12 cells injury in a concentration-dependent manner. Overall, CSP-2 may be useful as a naturally potential antioxidant agent for application in food and medicinal fields.