动物免疫增效剂黄芪多糖化学组分及其结构分析

Analysis on chemical components and structure of Astraglus polysaccharides

应用微波辅助提取技术从内蒙古黄芪的干燥根中获得黄芪多糖(Astraglus Polysaccharides,APS);确定中性蛋白酶与APS质量比为1:200,50℃水浴酶解2h为脱除APS中蛋白质的最佳条件;除蛋白后的APS过DEAE-cellulose52柱、透析袋和SephadexG-100柱纯化,经醇沉、真空干燥后,高效凝胶过滤色谱法(HPGPC)测得其分子量(Mw)为1.1×104Da,纯度为97.16%;以1-苯基-3-甲基-5-吡唑啉酮(PMP)为衍生剂,经柱前衍生化HPLC分析,确证APS的单糖组成为Rha、Glc、GalA和Ara,其摩尔比为1.19:72.01:5.85:20.95;红外光谱、13C核磁共振和1H核磁共振技术确定本实验所得APS其主链由葡萄糖以α-型糖苷键连接而成,前期实验证实其具有增强机体免疫功能和抗氧化作用。

Astraglus polysaccharide（APS）was isolated from the dry roots of Astragalus membranaceus（Fisch）Bunge var.mongholious（Bunge）Hsiao using microwave-assistant extracting techuique.The optimum process conditions of deproteinizing in APS were as follows.the ratio of neutral proteinase to crude extract of APS was 1：200,and the enzymolysis in waterbath was at 50℃ for 2h.Deproteinized APS was further porified using DEAE-cellulose 52 column chromatography,dialysis and Sephadex G-100 column chromatography.High performance gel-filtration chromatography（HPGFC）indicated that the relative molecular mass of APS was 1.1×10^4 Da with purity of 97.16%.The chemical components of APS were Rha,Glc,Gal and Ara with molar ratio of 1.19：72.01：5.85：20.95 by precolum derivatization high perormance liquid chromatography （HPLC）used 1-phenyl-3-methyl -5-pyrazolone（PMP）as derivatizing agent.It had been confirmed by infrared spectra and ^13C or^1H nuclear magnetic resonance （NMR）that the principal chain of APS was Gle linked by α-glucosidic bond.