黄芪中一种新杂聚多糖的理化分析

 目的分析蒙古黄芪中一种杂聚多糖的理化性质。方法应用微波萃取技术提取黄芪多糖(Astragalus polysaccharides,APS),采用蛋白酶法脱除其中的蛋白质,高效凝胶过滤色谱法(HPGFC)测定其分子量(M_w),柱前衍生化高效液相色谱(HPLC)测定其单糖组成及其分子摩尔比,红外光谱、1H核磁共振测定其主要化学构型,热失重(TG)和差示扫描量热法(DSC)对其进行热分析。结果提取物的分子量(M_w)为1.1×10⁴、纯度为97.16%,其单糖组成及其分子摩尔比为Rha-Glc-Gal-Ara=1.19∶72.01∶5.85∶20.95,主要化学构型为α-吡喃构型,主链部分由Glu1→6糖苷键构成,对光、热及湿均不稳定。结论提取物为黄芪中一种新的杂聚多糖。

Physical and Chemical Analysis of a New Heteropolysaccharide from Radix Astragalus

OBJECTIVE To analyze the physico-chemical properties of a heteropolysaccharide extracted from the dry roots of Astragalus membranaceus(Fisch.) Bunge var.mongholious(Bunge) Hsiao.METHODS Astraglus polysaccharide(APS) was obtained using Microwave-assistant extracting technique.Crude APS was deproteinized by the enzymolysis of neutral proteases.The relative molecular mass,chemical components and molecular molar ratio,and main configuration of the purifired APS were obtained by high performance gel filtration chromatography,MP-derivation high performance liquid chromatography,infrared spectra and/or 1H-NMR.Thermoanalysis was carried out with derivative thermogravimetry(DTG) and differential scanning calorimetry(DSC).RESULTS The relative molecular mass of the APS was 1.1×10⁴ with the purity of 97.16%.The heteropoly saccharide consisted of Rha,Glc,Gal and Ara with the molecular molar ratio of 1.19:72.01:5.85:20.95 and its main configuration was α-pyran ring with the principal chain linked by Glc 1→6 glucosidic bond.It was unstable to strong light,heat and humidity.Its effects on immune modulation and antioxidation were evaluated before.CONCLUSION The APS obtained in the experiment is a new heteropolysaccharide from Radix Astragalus.