目的 研究香菇子实体蛋白多糖Le－3的结构性质。方法 凝胶渗透色谱法测定相对分子量，红外扫描、气相色谱、β－消去反应和琼脂糖凝胶电泳等方法阐述多糖的结构，比色法测定糖及蛋白质的含量。结果 该多糖的重均分子量和数均分子量分别为13700和12500，红外扫描有典型的多糖吸收峰，糖苷键为β型。单糖组成为阿拉伯糖、木糖、甘露糖、半乳糖、葡萄糖和葡萄糖醛酸，中性糖摩尔比为Ara∶Xyl∶Man∶Gal∶Glu=0．31∶0．47∶1．00∶1．15∶8．92，总糖含量为70．62%，蛋白质含量为25．31%，多糖与蛋白质为非O－糖苷键连接。Le－3中含有RNA。结论 Le－3是从香菇子实体中分离得到的一种新类型多糖。

Object To study the structural characteristics of protein-bond polysaccharide Le-3 from the fruitbody of Lentinus edodos (Berk.) Pegler. Methods Relative molecular weights were determined by gel permeation chromatography. Structural characteristics were expounded by infra-red scan, gas chromatography, β-elimination reaction and Sepharose gel electrophoresis. The content of total polysaccharide and protein were determined by colorimetry. Results Mean molecular weight and molecular number of Le-3 were 13 700and 12 500. Typical absorption peak of the polysaccharide as show nin infra-red spectrum was of β-type glycosidic linkage. Le-3 was composed of arabinose, xylose, mannose, galactose, glucose and glucuronic acid. The molar ratio of the neutral saccharides was Ara∶ Xyl∶ Man∶ Gal∶ Glu= 0.31∶0.47∶ 1.00∶ 1.15∶ 8.92. The content of total saccharide and protein were 70.62% and 25.31% . The saccharides were not linked to peptides chain through O-glycosidic linkage. Le-3 contained RNA. Conclusion Le-3 was a kind of new type polysaccharide isolated from the fruitbody of L. edodes.