赤芝多糖肽GL-PP-3A的分离纯化和结构研究

分离纯化赤芝多糖肽，得到具有活性部位GL-PP-3A，对其进行结构分析。水提醇沉透析得赤芝多糖肽，经分级沉淀，Bio-Gel P-10柱色谱纯化得GL-PP-3A。经HPGPC、糖基组成、甲基化分析、 ¹H NMR和 ¹³C NMR等方法研究分析GL-PP-3A的结构。GL-PP-3A是以葡萄糖为主的杂多糖，含Rha、Xyl、Man、Gal、Glc糖残基和17种氨基酸。其M_w为1.7×10⁴；M_n为1.1×10⁴；M_w/M_n为1.49。M_p为1.3×10⁴。该多糖主链由1,6-或1,3-连接的β-D-Glcp构成，二者的比例约为2∶1，在部分1,6-连接的主链葡萄糖的2或3位有分支，分支的非还原末端均主要为β-D-Glcp,少量为鼠李糖，分支内部含有1～3个1,6-连接的β-D-Galp或1,3-连接的α-D-Manp。

Isolation, purification and structural analysis of GL-PP-3A, an active polysaccharide peptide from Ganoderma lucidum

GL-PP-3A, an active polysaccharide peptide, was isolated and purified from Ganoderma lucidum, and then its structure was analyzed. Crude polysaccharide peptides were extracted from Ganoderma lucidum with hot water, precipitated with ethanol and then dialyzed from Ganoderma lucidum. Subsequently GL-PP-3A was isolated and purified from the crude polysaccharide peptides by fractional precipitation and chromatography of Bio-Gel P-10 column. The repetitive unit of GL-PP-3A was analyzed by high performance gel permeation chromatography (HPGPC), monosaccharide composition and methylation analysis, 1H NMR and 13C NMR. GL-PP-3A is a heteropolysaccharide which is composed mainly of glucose (Glc), and also contains saccharide residues such as rhamnose (Rha), xylose (Xyl), mannose (Man) and galactose (Gal) and 17 kinds of amino acids. Its weight-average molecular weight (Mw) and number-average molecular weight (Mn) were 1.7 x 10(4) and 1.1 x 10(4), respectively, with the ratio of Mw/Mn ( molecular weight distribution) being of 1.49. Its backbone chain is composed of 1,6-linked beta-D-Glcp and 1,3-liked beta-D-Glcp at a ratio of 2:1. Some of 1,6-linked glucose residuals of the backbone chain are substituted at 2-0 or 3-0, and there are 1 to 3 1,6-linked beta-D-Galp or 1,3-linked alpha-D-Manp in the branched chains, the nonreducing ends of which consist mainly of beta-D-Glcp and a few Rha.