香菇菌盖多糖的提取纯化及其理化性质的研究

STUDIES ON EXTRACTING, PURIFICATION, CHEMICAL AND PHYSICAL PROPERTIES OF POLYSACCHARIDES FROM SHIITAKE CAP

采用水浸法、碱浸法从香菇菌盖中提取粗多糖 ,经乙醇沉淀、Sevag法脱蛋白、CTAB络合沉淀、氯化钠溶液溶解、透析 ,得到 2种多糖 :Lew(水浸物 )和Lea(碱浸物 )。经PAGE电泳、纸层析、紫外光谱分析鉴定 ,两者都为均一组分。Lew的纯度为 79.1% ,Lea为 83.2 %。改良型膜渗透压法测分子量 ,Lew的分子量为 8.31× 10 4 ;Lea为 9.4 0× 10 4 。经红外光谱分析 ,Lew、Lea具相似结构 ,但不是同一物质 ,它们具多糖的特征吸收峰 ,是 β 酸性异多糖。采用纸层析、气相色谱分析 ,检测多糖的单糖组成及其摩尔比 ,Lew为Ara∶Rha∶Xyl∶Gal∶Glc =4 .36∶2 .0 3∶1.0 0∶5.64∶13.80 ;Lea为Ara∶Rha∶Xyl∶Gal∶Glc =9.37∶1.0 0∶1.64∶7.19∶2 3.36。

Using water extracted and alkali extracted methods, precipitated with alcobol and CTAB, protein thrown away with Sevag method, dissolved with NaCl solvent, dialysed with water, two kinds of polysaccharides, Lew (the water extracted component) and Lea(the alkali extracted component), were gained from shiitake cap. Identified by paper chromatography, PAGE electrophoresis and ultraviolet spectrum, it was proved that both lew and lea were of homogeneous compositions. The purity of Lew, Lea is 79.1% and 83.2% respectively with component analysis. Their number average molecular weight is 8.31×10\+4 and 9.40×10\+4 respectively. Lew and Lea are not the same substances with similar structure by infrared spectrum anlysis. They have typical polysaccharide absorption peaks and are β acid heteropolysaccharides. By paper chromatography and gas chromatography analyses, their compositions of monosaccharides and olecular ratio were gained: Lew, Ara∶Rha∶Xyl∶Gal∶Glc=4.36∶2.03∶1.00∶5.64∶13.80;Lea, Ara∶Rha∶Xyl∶Gal∶Glc=9.37∶1.00∶1.64∶7.19∶23.36.\;