马齿苋多糖POPⅡ的分离纯化及理化性质研究

Study on Isolation-Purification of Polysaccharide POPⅡ from Portulace Oleracea L. and Its Physico-Chemical Characteristics

为研究马齿苋多糖组分的性质,采用水提醇沉方法从马齿苋全草中提取粗多糖,通过Sevage法脱蛋白质后,再经DEAE-纤维素柱层析和Sephadex G-200葡聚糖凝胶柱色谱分离纯化得到马齿苋精多糖POPⅡ,由醋酸纤维薄膜电泳和Sephadex G-200葡聚糖凝胶过滤法鉴定为均一性组分,化学定性反应和光谱鉴定表明POPⅡ不含蛋白质和核酸、不含酚类物质,但含有糖醛酸的非淀粉类多糖,其相对分子质量为12 100。POPⅡ完全酸水解后经薄板层析、气相色谱分析(结合半乳糖醛酸含量),确定它由阿拉伯糖、半乳糖和半乳糖醛酸组成,其中阿拉伯糖∶半乳糖的摩尔比为1.00∶1.05,其组成中半乳糖醛酸含量为9.18%。红外光谱分析表明POPⅡ具有典型的多糖吸收峰,结构中存在β-型糖苷键。

To study characteristics of polysaccharide from Portulaceoleracea L, the crude polysaccharide extracted with hot water and precipitated with alcohol was separated from the Portulace oleracea L. After protein was removed by Sevage method, the refined POP Ⅱ was isolated and purified by DEAE-cellulose column and Sephadex G - 200 column. Its homogeneity was proved by cellulose acetate film electrophoresis and Sephadex G- 200 column. POP Ⅱ was a non-starch polysaccharide without any protein, the nucleic acid and polyphenol, but with uronic acid. Its average relative molecular mass was 12100. After complete hydrolysis with acid, the monosaccharide was identified by TLC and GC as Arabinose,and Galactose. The molar ratio of Arabinose and Galactose was 1.00 ： 1.05, and the content of galacturonic acid was 9. 18%. The analysis result of IR spectra of POP Ⅱ showed that there were characteristic absorption hands of polysaccharide and β- glycoside linkage in its structure.