Total Fractionation and Analysis of Polysaccharides from Leaves of Panax ginseng C. A. Meyer

The water-soluble polysaccharides isolated from the leaves of Panax ginseng C. A. Meyer were totally fractionated into one neutral fraction(GLPN-1); six acidic fractions(GLPN-2, GLPA-1a, GLPA-1b, GLPA-1c, GLPA-2 and GLPA-3) by a combination of ethanol precipitation, ion-exchange and gel permeation chromatography. All the fractions were analyzed by determining monosaccharide composition, molecular weight distribution. The results show that GLPN-1 was mainly composed of Gal(38.1%) and Ara(33.6%) and presumed to be an arabinogalactan. GLPA-1a, GLPA-1b and GLPA-2 mainly contained Gal, Ara, Rha and GalA. The amount of Gal and Ara acounted for over 50% of total sugar and the amount of Rha was more than 10%. The molar ratios of Rha/GalA in GLPA-1a, GLPA-1b and GLPA-2 were 1:1, 1:2 and 1:2.7, respectively, indicating that they belong to type-I rhamnogalacturonan (RG-I)-rich pectin. GLPA-1c was mainly composed of GalA(78%), belonging to homogalacturonan(HG)-rich pectin. GLPA-3 might be a glycoprotein.