桑枝多糖的分离纯化及结构初步分析

Separation,purification and preliminary structure analysis of Ramulus Mori polysaccharide

目的:从桑枝中分离纯化出桑枝多糖,并研究其组成及初步结构。方法:桑枝经水提醇沉,脱蛋白、DEAE-纤维素柱和SephadexG-100柱层析,得RMPS1和RMPS2二个多糖组分,采用TLC、GC、HPLC、IR和Smith降解等方法分析其组成和初步结构。结果:RMPS1和RMPS2的平均分子量分别为:5.8×105,6.5×105,RMPS1有鼠李糖、阿拉伯糖、葡萄糖、半乳糖组成,其摩尔比为:1.08∶1∶1.40∶1.57;RMPS2有鼠李糖、葡萄糖和半乳糖组成,其摩尔比为:11.38∶1∶1.35;通过高碘酸氧化和Smith降解初步分析,RMPS1、RMPS2中连接方式主要为1→2、1→4糖苷键,此外包括1→3糖苷键,红外光谱显示,均具有糖的特征吸收峰。结论:首次测定桑枝多糖RMPS1和RMPS2的初步结构,为桑枝多糖的进一步研究提供依据。

AIM： To study the isolation,purification and characterization of Ramulus Mori polysaccharide. METHODS： Ramulus Mori was extracted by boiling water. The raw extract was precipitated fractionally by alcohol deproteinized,passing through DEAE ion exchange cellulose （ DEAE-52） and SephadexG-100,obtained RMPS1 and RMPS2. The composition and characterization of Ramulus Mori polysaccharide were researched by TLC、IR、 GC、HPLC and smith degradation. RESULTS： The molecular weight of RMPS1 and RMPS2 were 5. 8 × 105 and 6. 5 × 105; RMPS1was made up of rhammose、arabinose、glucose and galactose with the molarity rate of 1. 08 ∶ 1 ∶ 1. 40 ∶ 1. 57; RMPS2 of rhammose、glucose and galactose with the molarity rate of 11. 38 ∶ 1 ∶ 1. 35. Smith degradation showed that the main linkage form in RMPS1 and RMPS2 was 1→2 and 1→4 glycosidic linkages,But some 1→3 glycosidic linkages also existed in the molecules; infrared spectrum showed that both had the polysaccharide characteristic absorption peaks. CONCLUSION： The structures of RMPS1 and RMPS2 are first determined from Ramulus Mori.