Research on extraction,purification and antioxidant activity in vitro of polysaccharide from ginseng berry

In this study,polysaccharide fractions(WGBP)from ginseng berry was obtained by water-extraction and ethnol-precipetation. Through the ion-exchange chromatography,one neutral fraction(WGBP-N)and three acidic fractions(WGBP-1,WGBP-2,WGBP-3)were obtained. The monosaccharide composition and molecular distribution were analyzed by HPLC and gel permeation chromotography. DPPH and hydroxyl free radicals scavenging activities were carried on to value the antioxidant activity. The results were showed that WGBP was mainly consisted by rhamnose(Rha),galacturonic acid(GalA),galactose(Gal),arabinose(Ara)and glucose(Glc). WGBP-N was composed of Gal,Ara and Glc with a ratio of 62.7:17.0:17.1,three acidic fractions were mainly composed by Rha,GalA,Gal and Ara with different proportion. WGBP had obvious DPPH and hydroxyl free radicals scavenging activities with a concentration dependent tendency. The DPPH and hydroxyl free radicals scavenging rates were 62.7% and 81.2% when WGBP were at 2.0 and 0.2 mg/mL,respectively. WGBP showed more significant antioxidant activity than its sub-fractions.