[关键词]
[摘要]
目的 从中药黄芪中提取免疫活性多糖并研究其化学结构。方法 用乙醇分级沉淀、脱蛋白、CTAB选择性沉淀、离子交换及凝胶过滤柱层析的方法从黄芪水提物提取均一多糖 ;运用凝胶过滤法确定多糖的均一性和分子量 ;运用糖组成分析、甲基化分析、Smith降解、IR及13CNMR等方法研究多糖的结构。结果 得到均一多糖A2 Nb。其平均分子量为 360000,由 D-葡萄糖组成,主要连接方式为 α- D-(1→ 4) - Glc,在每 25个葡萄糖中有一个 6 -O位上的分枝。结论 从黄芪中首次分离到具有促脾细胞增殖作用的高分子量葡聚糖 A2 Nb。
[Key word]
[Abstract]
Object To isolate the immunoactive polysaccharide from Astragalus mongholicus Bunge and elucidate its chemical structure Methods The polysaccharide was purified from water extracts of A mongholicus by ethanol precipitation, deproteination, selective precipitation with hexadecyltri-methylammonium-bromide, ion-exchange and gel-filtration chromatography Its homogeneity and molecular weight were estimated by gel-filtration chromatography, the structure was deduced from sugar analysis, methylation analysis, Smith degradation, IR and 13CNMR spectrophotometry Results A homogeneous polysaccharide A2Nb was obtained with a molecular mass of 360000, and composed of D-glucose with a major linkage form of α- D-(1→ 4) - glucose Side chains were found at 6-O positions once in every 25 glucose residues Conclusion A high molecular weight glucan A2Nb was obtained from A mongholicus for the first time It showed the ability of promoting the proliferation of the splenocytes of mice.
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[基金项目]
国家自然科学基金重点资助项目No.39730480