Purification And Identification Of An Acidic Polysaccharide Fraction GFLA-1 From The Flowers Of Panax Ginseng C. A. Meyer

The polysaccharides of ginseng flowers have been purified in our laboratory. Meanwhile some structures of ginseng flower polysaccharides were analyzed and activities were studied. In this paper, an acidic polysaccharide fraction GFLA-1 was prepared and purified from ginseng flowers. Furthermore, the monosaccharide composition, property and structural feature of GFLA-1 were studied.Ginseng flower water-soluble polysaccharide GFL (79.1g) was extracted by boiled water and precipitated with alcohol in dry ginseng flower. The monosaccharide composition was analyzed by HPLC and the molar ratio of GFL was Man:Rha:GlcA:GalA:Glc:Gal:Xyl:Ara=3.1:2.2:0.9:16.0:8.2:52.3:1.5:10.8. A neutral sugar fraction GFLN and four acidic sugar fractions named GFLA-1, GFLA-2, GFLA-3, GFLA-4 from GFL, were fractionated by DEAE-cellulose column chromatography. The contents, compositions and molecular weights of above five fractions were compared and analyzed with other samples in our laboratory. Two grades GFLA-1-A and GFLA-1-B of different molecular weight was analyzed by Sepharose CL-6B column to further research GFLA-1 in this paper .GFLA-1-A was showed a single symmetrical peak by HPGPC and Sepharose CL-6B column chromatography. The molecular weight of GFLA-1-A was about 9.1×104 Da. The monosaccharide composition of GFLA-1-A was analyzed by HPLC. The result showed that mainly composition of GFLA-1-A was galactose and arabinose. The contents of them were 58.3% and 34.4% respectively (the ratio of two sugars was closed to 2:1). The two sugars combined for 90% of the total content. In addition, small amounts of rhamnose (4.4%), galacturonic acid (2.3%) and mannose (0.6%). Therefore, due to the ratio of rhamnose and galacturonic acid were very nearly, we speculated that GFLA-1-A may be either arabinogalactan with some side chains of galactan or the mixture of RG-type pectins.GFLA-1-B was showed a single peak in high performance by HPGPC and the Sepharose CL-6B column chromatography. The peaks of total sugars and uronic acid were shown symmetrical and consistent. Distribution of theses molecular weights was concentrated and about 4.7×103 Da. The monosaccharide composition of GFLA-1-B was complex and the main sugar was Gal (35%). The second major sugar was GalA (27.3%), Ara was about 17%. The contents of above three sugars were reached to 80% of GFLA-1-B. In addition, there were other monosaccharides—Rha(5.8%), GlcA(4.9%)and Glc(4.5%). The ratio of Galactose and Arabinose was 2:1, we suggested that there were arabinogalactans of Galactose and Arabinose in it. Additionally, due to Rha and GalA were presented, we suggested that there was HG- and RG-type domains in GFLA-1-B.