A Novel Polysaccharide from the Fruits of Cudrania Tricuspidata and Its Antioxidant and Alcohol Dehydrogenase Activating Ability

In the present study, polysaccharides from the fruits of Cudrania tricuspidata were purified hierarchically using DEAE-52 cellulose columns and Sephadex S-100 gel columns. Two fractions were obtained and named ZGs-1 and ZGs-2. The in vitro antioxidant and alcohol dehydrogenase activities of ZGs-1 and ZGs-2 were also analyzed. Two grades named ZGs-1 and ZGs-2 were obtained with molecular weights of 131.521 and 94.551 KDa, respectively, and both consisted of arabinose, galactose, glucose and small amounts of xylose and rhamnose. The structural resolution of these two levels by FT-IR, methylation and NMR showed that the major sugar residue types of ZGs-1 are: →3)-β-D-Galp-(1→, α-L-Araf-(1→, →3,6)-β-D-Galp-(1→, β-D-Xylp-(1→, →5)-α-L-Araf-(1→, →3,5)-α-L-Araf-(1→, →4)-α-D-Glc-(1→. The main sugar residue types of ZGs-2 are: →6)-β-D-Galp-(1→, →5)-α-L-Araf-(1→, →3,6)-β-D-Galp-(1→, →3,5)-α-L-Araf-(1→, →4)-β-D-Glc-(1→, α-L-Araf-(1→. ZGs-1 showed weak antioxidant activity. ZGs-2 showed good scavenging effects on DPPH and hydroxyl radicals, as well as on iron ion reduction ability, and the activation rate of alcohol dehydrogenase reached 92.15%, indicating that the novel polysaccharide ZGs-2 is a potential antioxidant and hepatoprotective agent.