硫酸化发酵灵芝胞外多糖的组成与结构

Constituents and Structures of Sulfated Extracellular Polysaccharides from Ganoderma lucidum Fermentation Broth

从灵芝深层发酵液中获得的灵芝胞外多糖,经硫酸化后其抑癌活性大幅提升。硫酸化后,灵芝胞外多糖的结构和构象都发生一定的变化。经单糖组成分析和光谱初步解析,硫酸化灵芝胞外多糖的单糖组成为鼠李糖、阿拉伯糖、甘露糖、葡萄糖、半乳糖,其摩尔比为9∶3∶2∶4∶48;其主链可能是以α-D-Gal(1→6)为主或混杂有α-D-Gal,Rha,α-D-Glc,α-D-Man以及Ara为侧链,其硫酸基团可能接在C-3、C-4、C-6位上。硫酸化前灵芝多糖的构象主要为单螺旋结构,而修饰后呈三维螺旋结构,x-衍射亦证实其结构的有序变化。

The sulfation of extracellular polysaccharides of Ganoderma lucidum （GLP）from the submerged fermentation broth can dramatically enhance their antitumor activity. The structure and conformation of GLP might change due to the sulfation. The structure of the sulfated GLP was analysized with glycosyl residual composition analysis,IR,UV and NMR. The polysaccharide consists ofrhamnose ,arabinose ,mannose ,glucose and galactose with a molar ratio of 9 ： 3： 2 ： 4 ： 48. The main chain of the polysaccharide may consist of the unit of a -D-GIc （ 1→6 ）or the side chain is mixed of o -D-Glc, Rha, a -D-Man, and Ara. The sulfate groups may be connected to C-3, C-4, and C-6 of the sugar unit. Meanwhile,the sulfated polysaccharides present very different conformation comparing to the native polysaccharides. The sulfated polysaccharides possessed a triple helix whereas the native polysaccharide preferred the single helical, which was also confirmed by x-ray diffraction.