灵芝子实体水溶性多糖的分离和分子量测定

用磷酸盐缓冲液、热水、碱和热碱水分别从灵芝子实体分离出五种水溶性杂多糖ＧＬ１、ＧＬ２、ＧＬ３、ＧＬ４和ＧＬ５．紫外光谱、红外光谱、气相色谱及硫酸咔唑分析结果表明，它们主要由葡聚糖、木糖、甘露糖、半乳糖组成，ＧＬ３、ＧＬ４和ＧＬ５含葡萄糖醛酸．由粘度、光散射和膜渗透压法测定了特性粘度［η］、重均分子量Ｍｗ及数均分子量Ｍｎ，ＧＬ２、ＧＬ３和ＧＬ５多糖的Ｍｗ值分别为１２４×１０４、１２８×１０４和５８×１０４．实验结果表明这些杂多糖含水溶性Ｄ 葡聚糖，并且初步推断，用磷酸盐缓冲液提取出的杂多糖ＧＬ２中包含刚性链β Ｄ 葡聚糖

ISOLATION AND DETERMINATION OF MOLECULAR WEIGHTS OF WATER SOLUBLE POLYSACCHARIDES FROM FRUITING BODY OF GANODERMA LUCIDUM

Five water soluble heteropolysaccharides (GL1,GL2,GL3,GL4 and GL5) were isolated from phosphate buffer, hot water, alkali and hot alkali extracts of the fruiting body of Ganoderma lucidum. The results analysed by UV, IR,gas chromatography and uronic acid carbazole reaction showed that they were mainly composed of glucose, xylose, mannose and galactose, and GL3, GL4 and GL5 contained glucoronic acid. The intrinsic viscosities , weight average molecular weights M w , number average molecular weights M n were determined by viscometry, light scattering and memberane osmometry. The values of M w for samples of GL2,GL3 and GL5 are 124×10 4,12 8×10 4 and 5 8×10 4 respectively. From analysis of the data, we deduced roughly a conclusion that these heteropolysaccharides contained water soluble D glucan, and GL2 extracted from phosphate buffer included a β D glucan with stiff chains.