松杉灵芝发酵菌丝体中水溶多糖的分离纯化与结构的比较研究

松杉灵芝发酵菌丝体经热水提取,冻融分级及乙醇二次分级,分离纯化出GFb级份,电泳及凝胶柱层析示其为均一多糖,分子量为9.8万。小于子实体多糖相应级份。 GFb经红外光谱,气相色谱,气质联机,碳13核磁共振,高碘酸盐氧化,Smith降解,甲基化及部分酸水解分析,确定其基本结构中主链为1→6葡萄糖基和1→6半乳糖基构戍,二者之比为1∶1,分支点在0-3位上,分枝点率为50％,与子实体多糖GF_3相同,侧链由1→3葡萄糖基,1→4葡萄糖基,末端葡萄糖基及末端半乳糖基构成,分子中分枝率为55.6％,较子实体多糖GF_3分枝率略低,分枝链略短。

ISOLATION, PURIFICATION AND STRUCTURAL COMPARISON INVESTIGATION OF WATER SOLUBLE POLYSACCHARIDE GFb OF FERMENTED MYCELIA FROM GANODERMA TSUGAE

The water soluble polysaccharide GFb was isolated and purified from fermented mycelia of Ganoderma isugae. Its homogeneity was comfirmed by chroma-tography on Sepharose CL-4B and glass fiber electrophoresis. Its molecular weight estimated by gel filtration is 98000. By means of IR, GC, GC-MS, 13C-NMR, periodate oxidation, Smith degradation,, methylation analysis and partial hydrolysis, etc., the structure of GFb was identified. Its basic structure is composed of (1-6)-linked galactose and (1-6)-linked glucose residues in main chain, and (1-)-linked galactose, (1-3)-linked and (1-4)-linked glucose residues in side chains. Side chains attached to 0-3 of glucose and galactose residues in main chain. The rate of branch points is 50 percent in main chain and branch rate is 55.6 percent in molecules.