肉苁蓉茎水溶性多糖的结构研究

【作者】 赵伟；

【导师】 梁忠岩；

【作者基本信息】 东北师范大学 ， 生物化学与分子生物学， 2004， 硕士

【摘要】 从野生肉苁蓉的茎中分离水溶性多糖，粗多糖经Sevage法脱蛋白、反复冻融、高速离心、超滤分级等方法，得级分SPA，经高压液相色谱等方法证明SPA为均一组分，气相色谱分析，SPA的单糖组成为Ara、Rha、Man、Gal、Glc．摩尔比依次为1．83：1．00：3．06：4．56：14．74以上结果表明多糖SPA是以葡萄糖和半乳糖为主兼有阿拉伯糖鼠李糖和甘露糖的中性杂多糖．其分子量为0．76×104 对SPA的结构研究采取了13C-NMR分析，部分酸水解，高碘酸氧化，Simth降解，I．R．分析，G．C．分析，甲基化分析等方法，甲基化产物经水解、还原、乙酰化后用G．C．--M．S．进行测定。 结果分析表明：SPA为少分枝结构；其主体结构由Glc组成，其中(1—6)Glc构成主链的核心结构，(1—6)Glc在0—3处有分枝；平均每七个己糖残基有一个分枝残基；A，B为侧链结构，其构成分别为-末端残基为1--Ara；其重复结构单位可能为： 支链的结构为更多还原

【Abstract】 A water soluble polysaccharide has been isolated from the stem of the wild Cistanche salsa G.Beck. The crude polysaccharide was deproteinized by Sevage method, freezed-melted repeatedly, and fractionated by hydrogen peroxide solution and ultrafiltration, giving a polysaccharide fractions termed SPA. Its homogeneity was proved by HPLC etc. GC show it consists of Rha, Ara, Man, Gal and Glc with the molarity rate of 1:1.83:3.06:4.56:14.75 in turn. These indicated that SPA was a kind of neutral heteropolysaccharide, as well as it consisted mainly of glucose and some galactose, Ala, Rha and Man. Average molecular weight of SPA was around 0.76×104.In the structure analysis of SPA,13C-NMR, partial hydrolysis with acid, periodate oxidation, Smith degradation, I.R. ,G.C. and methylation etc. were the principal methods used. After acetylation, the methylated productions were analyzed by G.C.-M.S.The results revealed that SPA was a kind of low branched structure. The main chain was composed of (1 -- 6)-linked-Glc, and (1--6)-linked-Glc residues were substituted at O-3. On average, there are 1 branche among 7 main chain residues; A and Bwere side chains, they are composed of (1 --4)-linked-Gal, (1 — 4)linked-Man, (1 — 3)-linked-Gal and (1 — 2)-linked-Rha residues. So itd possible repeated unit was:The side chains were:更多还原