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桑白皮为桑科植物桑Morus alba L.的干燥根皮,是临床上常用的中药.采用沸水提取获得桑白皮中的多糖,用乙醇沉淀、阴离子交换柱层析、凝胶过滤层析等方法进行分离和纯化,从水提粗多糖中得到均一多糖CMA-a-1,CMA-a-5和CMA-b1-1.应用糖组成分析、甲基化分析及IR,NMR等光谱学方法研究桑白皮多糖的结构及性质.结果表明,CMA-a-1,CMA-a-5均为淀粉类多糖,前者结构类似于支链淀粉,但O-6位上取代的支链中含有1,6-连接葡萄糖,平均链长为23;而后者更接近于直链淀粉,平均链长为30.CMA-b1-1为以1,2-连接的鼠李糖及1,4-连接的半乳糖醛酸为主链的RG-I型果胶类多糖,具有多种形式的由阿拉伯糖、半乳糖、木糖等构成的支链.CMA-b1-1对SMMC7721肝癌细胞生长具有抑制作用,对L02正常肝细胞生长则没有抑制作用.本研究表明桑白皮水提多糖中主要是淀粉类和果胶类多糖.
Morus alba is the dry root bark of the mulberry Morus alba L. It is a commonly used traditional Chinese medicine in the clinical practice.It was extracted by boiling water to obtain the polysaccharide in the mulberry white bark, which was precipitated with ethanol, anion exchange chromatography and gel filtration chromatography The polysaccharides CMA-a-1, CMA-a-5 and CMA-b1-1 were obtained from the water-extracted crude polysaccharides by means of methods such as sugar composition analysis, methylation analysis and IR, NMR and other spectroscopy Methods The structure and properties of polysaccharides from Morus alba were studied.The results showed that both CMA-a-1 and CMA-a-5 were starch polysaccharides, the former structure was similar to that of amylopectin, but branched Contains 1,6-linked glucose with an average chain length of 23, while the latter is closer to amylose with an average chain length of 30. CMA-b1-1 is a 1, 2-linked rhamnose and 1,4- The linked galacturonic acid-based RG-I type pectin-based polysaccharide has various forms of branches composed of arabinose, galactose, xylose, etc. CMA-b1-1 has the ability to grow SMMC7721 hepatoma cells with Inhibition, no effect on L02 normal liver cell growth.This study shows that the main polysaccharide Cortex Mori water-soluble starch and pectic polysaccharides.