通过水提法得到人参果中的总多糖(WGBP),并通过离子交换层析对WGBP进行分离纯化,得到一个中性糖WGBP-N和三个酸性糖级分(WGBP-1、WGBP-2、WGBP-3)。利用高效液相色谱及分子筛层析法对各个级分的单糖组成、分子量等进行了分析,并对结构特点进行了概括。通过DPPH和羟自由基清除实验分析了各级分的抗氧化活性。结果表明,WGBP主要由鼠李糖(rhamnose,Rha)、半乳糖醛酸(galacturonic acid,GalA)、半乳糖(galactose,Gal)、阿拉伯糖(arabinose,Ara)和葡萄糖(glucose,Glc)组成,分子量分布广泛。WGBP-N主要由Gal、Ara和Glc组成,比例为62.7:17.0:17.1。三个酸性糖主要由不同比例的Rha、GalA、Gal和Ara构成。WGBP具有明显的DPPH·和羟自由基清除活性,且清除率随浓度的升高而逐渐增强。当WGBP浓度为2.0 mg/mL时,DPPH·清除率为62.7%;当浓度为0.2 mg/mL时,羟自由基清除率为81.2%。WGBP对DPPH·和羟自由基清除活性优于四个子级分。
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.