Characterization and antioxidant activities of polysaccharides from Fructus corni

The composition and antioxidant activities of two polysaccharides PFCAIII and PFCCI, isolated from Fructus corni, have been investigated. The monosaccharide components of PFCAIII were found to be rhamnose, arabinose and glucose in a molar ratio of 13.74: 50.54: 35.72, whilst PFCCI was found to consist of xylose and glucose in a molar ratio of 18.8: 81.2. The weight-average molecular weights of PFCAIII and PFCCIwere 1.74x10(4) and 7.57x10(4) respectively. The polysaccharides showed potential antioxidant activity by scavenging superoxide anion (O-2(-)center dot) and hydroxyl free radicals (OH center dot) and this was confirmed by their ability to inhibit oxidation of axunge and gingili. The concentrations required to scavenge 50% of hydroxyl free radicals (EC50) of PFCAIII and PFCCI were 430 mu g/ml and 80 mu g/ml respectively, and the extents of scavenging O-2(-)center dot by 500 mu g PFCAIII and PFCCIwere 15.9% and 68.0% respectively. The polysaccharide PFCCI shows much more significant antioxidant activity than PFCAIII. PFCCI was mainly linked with beta(1 -> 4)-D-glucosyl with side chains including 1-linked beta-D-Glc, 1,6-linked beta-D-Glc and 1,4-linked beta-D-Xyl with branching points at C-6 of 1,4-linked Glc in main chain. It had the potential to be exploited by the food and pharmaceutical industries in the future with further research on this polysaccharide.