酸提香菇多糖的分离纯化及结构鉴定

Purification and Structural Analysis of a Polysaccharide from Lentinusedodes Extracted using an Acid Solution

本文研究了用盐酸水溶液从香菇柄中提取并分离纯化得到一种香菇多糖SP2,运用凝胶柱层析和滤纸电泳进行纯度鉴定,通过高效凝胶渗透色谱法测定分子量及其分布,利用紫外可见光谱法、气相色谱法、红外光谱法、X-射线衍射法、DSC热分析、高碘酸氧化法、Smith降解法和刚果红实验分析香菇多糖SP2的结构。分析研究表明SP2具有典型的多糖显色反应后的特征吸收峰,组成相对均一,相对分子量分布范围较窄,重均分子量为5.203×104 u;单糖组成为甘露糖、葡萄糖和半乳糖,其组成摩尔比为0.32:58.6:2.82;经高碘酸氧化和Smith降解后表明SP2中C-C单键有1→2键、1→3键和1→6键,且比例为9.43:5.44:1;SP2是一种含有吡喃环的糖蛋白缀合物,不能形成单晶,为无定型形态,在分子之间无较强的作用力存在,且具有螺旋结构。本研究结果为阐明香菇多糖的构效关系提供依据。

A new polysaccharide SP2 was isolated from Lentinusedodes using an aqueous HCl solution and purified using gel column chromatography,the purity was determined using filter paper electrophoresis.The relative molecular mass and distribution of SP2 were analyzed by high-performance gel permeation chromatography,and the structure was analyzed by UV-Vis spectroscopy,gas chromatography,infrared spectroscopy,X-ray diffraction,and differential scanning calorimetry,as well as periodate oxidation,Smith degradation,and Congo red experiments.The results indicated that SP2 showed a typical absorption peak for polysaccharides after the color reaction and had a relatively homogeneous composition.In addition,the molecular weight distribution range was relatively narrow,with a weight-average molecular weight of 5.203×104 u.SP2 was found to be composed of mannose,glucose,and galactose with a molar ratio of 0.32：58.6：2.82.Periodate oxidation and Smith degradation experiments indicated that the C-C bonds in the branches of SP2 were composed of（1→2）,（1→3）,and（1→6） linkages with a molar ratio of 9.43：5.44：1.SP2 was found to be a glycoprotein conjugate containing pyranose rings that was amorphous and could not form the monocry stalline structure.SP2 contained spiral structures and had no strong intermolecular interactions.These results provided evidence to explain the structure-activity relationships of polysaccharides from L.edodes.