红豆杉多糖的提取与结构初探

红豆杉枝叶经热水浸提、浓缩、醇沉、透析等工序制得一种红豆杉多糖,采用SephadexG-100凝胶渗透法测定分子质量,采用气相色谱法测定其单糖组成,并测定了不同纯度红豆杉多糖的红外光谱。所得红豆杉多糖分子质量约为59.2 ku,可视为由约365个糖残基构成的高分子化合物,其单糖残基鼠李糖、阿拉伯糖、甘露糖、葡萄糖、半乳糖数量比约为4∶6∶1∶1∶4。该红豆杉多糖分子结构中含有普通单糖、糖醛酸或氨基酸残基等,单糖主要以吡喃环形式存在、通过β-(1,3)苷键结合形成一种糖蛋白缀合物,Sevag法处理不能完全除去分子中的肽链。

Extraction of Maire Yew Polysaccharide and Its Structure

A polysaccharide was prepared from the branches and leaves of the Taxus chinensis var.mairei by the processing of hot water extraction,concentration,alcohol-precipitation,dialysis and protein isolation successively.The polysaccharide molecular weight was determined by Sephadex G-100 gel permeation chromatography.The monosaccharide composition of the taxus polysaccharide was determined by gas chromatography.And IR spectra of taxus polysaccharide were determined,too.The results showed that the taxus polysaccharide’s molecular weight was 59.2 ku,which composed of 365 monosaccharide groups.The ratio of Rhamnose,Arabinose,Mannose,Glucose and Galactose was 4 ∶ 6 ∶ 1 ∶ 1 ∶ 4.The taxus polysaccharide was a glycoconjugate that composed of several kinds of monosaccharide,glucuronic acid and amino acid.The monosaccharide was in the form of pyran ring and linked by β-(1,3) glucosidic bond each other.The peptide in taxus polysaccharide couldn′t be destructed by Sevag method.