Purification And Structural Analysis Of The Neutral Polysaccharide From Panax Ginseng C.A. Mey

A water-soluble crude polysaccharide has been extracted from ginseng roots. After deproteination by Sevage method and precipitation in ethanol, a mixture of polysaccharides GR was obtained. GR was divided into two fractions GRN and GRA by DEAE-Cellulose column. The carbohydrate content of GRN was 97.8% as determined by the method of phenol-sulfuric acid assay. Sugar composition analysis showed that GRN contained 95.37% glucose and trace arabinose and galactose.GRN was further fractionated by precipitation in different concentration of ethanol. The precipitate under each condition was recovered and analyzed for its starch content, sugar composition, and molecular weight distribution. Data showed that the precipitates obtained with less than 50% ethanol were mainly high molecular weight starch-containing polysaccharides. Whereas, the precipitates obtained with higher than 60% ethanol were mainly low molecular weight polysaccharides and oligosaccharides which contained galactose and arabinose in addition to glucose residues.The result of periodate oxidation and Smith degradation indicated that GRN was composed of 82% (1→)- and (1→6)-glycosidic linkages, 13% (1→4)- and (1→4,6)-glycosidic linkages and 5% (1→3)-glycosidic linkages.An oligosaccharide of 1500 Da, approximately 6-8 monosaccharides, was generated by periodate oxidation and Smith degradation of GRN. This oligosaccharide contained 52.3% glucose, 30.8% galactose, 14.8% arabinose and 2.1% mannose.