Bioactivity And Mechanism Of Chinese Yam(Dioscorea Opposite Thunb.)Tuber Polysaccharid

The crude polysaccharides of yam were extracted by water extraction and alcohol precipitation.And then compare the four deproteinization methods of TCA,Sevage,trypsin and papain.The pure polysaccharides were separated by DEAE Sepharose Fast Flow and Sephadex G-75 column chromatography.The molecular weight of the polysaccharide was determined and the antioxidant capacity was measured.The results are as follows:1.The best deproteinization method of yam polysaccharide is:using trypsin method.The optimal deproteinization conditions were:0.4ml enzyme solution,pH 7.5,37 ?hydrolysis 45min.And the use of papain deproteinization method is not suitable for Bike Qi yam.2.Two kinds of neutral polysaccharides and three acidic polysaccharides were obtained by DEAE Sepharose Fast Flow column chromatography and Sephadex G-75 column chromatography.They were named ZP-?,ZP-?,SP-?,SP-? And SP-?.3.The molecular weight of the polysaccharides,acid polysaccharide I and acid polysaccharide ? were 1795 Da,1774 Da and 1734 Da respectively by gel column chromatography.4.For the ABTS free radical scavenging ability,the best effect is the acid polysaccharide ?,and the four polysaccharides play an antagonistic effect.For the scavenging ability of hydroxyl radicals,the main scavenging effect is neutral polysaccharide and acid polysaccharide I.For the scavenging ability of DPPH free radicals,the scavenging ability of superoxide free radicals and the reducing power,the main role is neutral polysaccharide.