THE RESEARCH OF WATER-SOLUBLE POLYSACCHARIDE EXTRACTED BY ALKALI FROM GYNOSTEMMA PENTAPHYLLUM MAKINO

The water-soluble crude polysaccharide from Gynostemma pentaphyllum Makino by alkali extraction were studied in this paper. The material, pretreated, extracted by water and desiccated, then was extracted according to the optimal conditions and filtrated. The filtrate was operated step by step as following: modulat pH, remove starch, dialyze and precipitate with 4 times volume of absolute alcohol, then a crude polysaccharide was obtained. The crude polysaccharide was purified by the combined deproteinization methods of enzyme and Sevage, then dialyzed to creat AGM. It can be indicated that AGM has two components by Gel filtration chromatography on Sephadex G-100, one of which has combinative protein. The monosaccharides of AGM were analyzed by using HPLC. The results showed that: AGM was mainly composed of Rha, Xyl/Fuc( at least contained Xyl or Fuc) , Ara, Glu, and Gal, in the molar ratio of 2.43 : 1.00 : 3.02 : 2.59 :3.46.