紫芝细胞壁大分子量葡聚糖的纯化及结构鉴定

Purification and structure elucidation of high molecular weight polysaccharide from the cell wall of Ganoderma sinense

采用超微粉碎、热水浸提法从紫芝子实体水提残渣中获得细胞壁粗多糖,通过30%乙醇沉淀、20%醇洗的方法纯化出大分子量均一多糖GSCW30E-20E。苯酚硫酸法检测其多糖含量为98.03%,单糖组成分析显示其仅由葡萄糖组成,高效凝胶尺寸排阻色谱-多角度激光散射仪-示差折光检测技术测定其重均分子量为1.552×10~6g/mol。通过红外光谱、甲基化及核磁共振分析对其结构进行解析,结果表明,GSCW30E-20E是一种β-D-葡聚糖,该多糖主链由β-(1,3)-糖苷键连接而成,每3个糖残基主链上通过β-(1,6)-糖苷键连有一个葡萄糖残基为支链。

Cell wall polysaccharides were extracted by hot water extraction of superfine comminuted powder from water-extracted residue of Ganoderma sinense fruiting bodies.A high molecular weight polysaccharide GSCW30 E-20 E was purified by ethanol precipitation.The total sugar content of GSCW30 E-20 E determined by phenol-sulfate method was 98.03%.HPAEC results showed that its monosaccharide component is only glucose.The average molecular weight of GSCW30 E-20 E determined by HPSEC-MALLS-RI system was 1.552×10~6 g/mol.Structure analysis by using infrared spectroscopy,methylation and NMR indicated that GSCW30 E-20 E was a beta-(1,3)-glucan linked to a glucose residue by a beta-(1,6)-glycoside bond.The degree of branching is 0.33.