THE CHEMICAL STRUCTURE AND ANTIOXIDATIVE ACTIVITY OF POLYSACCHARIDE FROM ASPARAGUS COCHINCHINENSIS

AIM　To study the structure and antioxidative activity of polysaccharide from Asparagus cochinchinensis. METHODS AND RESULTS　the tube roots of Asparagus cochinchinensis was extracted with boiling water. From the extract, a polysaccharide, ACP₁ was separated using DEAE-cellulose and purified by Sephadex G-150 column chromatography. Its structure was studied by composition analysis, IR, periodate oxidation analysis, Smith degradation, CrO₃ oxidation, methylation analysis, ¹H and ¹³CNMR analysis etc. ACP₁ was found to be composed of Gal and Glc, in the ratio of 1.00∶0.87, with the molecular weight of 10.4×10⁴ and ［α］15D=+64(c 0.54, H2O). ACP₁ contained a backbone composed of 8β-(1→4) linked D-galactopyranosidic and 6α-(1→6) linked D-glucopyranosidic linkages, a glucosyl branch is attached to 3-O of a galactosyl residues of the main chain. The superoxide anion() produced by NBT-PMS-NADH system was scavenged and the lipid peroxidation induced by Fe²⁺-ascorbic acid in mouse liver microsome was inhibited, the hemolysis of rat RBC induced by H₂O₂ was antagonized. CONCLUSION　ACP₁ is a galacto-glucan and has distinctive effect of antioxidation.