【作者】 张继；

【导师】 王云普；

【作者基本信息】 西北师范大学 ， 高分子化学与物理， 2005， 博士

【摘要】 沙蒿多糖（ASP）,由于其优良的特性,如吸水性——可吸取自身重量60倍的水,高粘度——是明胶的1800倍,因此被广泛应用在食品,化学、生态等不同领域。然而,迄今为止,对其结构的研究尚未见国内外文献报道。 1.1980年文献报道采用硫酸水解和乙酰解,通过纸层析和Whatman纤维粉柱层析分析,认为ASP出D-葡萄糖、D-甘露糖、D-半乳糖、L-阿拉伯糖和木糖五种单糖组成。本文采用ASP的糖腈乙酰化衍生物,通过纸色谱、气相色谱、气质联用和采用ASP的TFA水解液通过高效液相色谱、离子色谱综合分析,确定了ASP的单糖组成及摩尔比。发现其化学组成与文献报道不同,ASP是由六种单糖组成,尚有第六种单糖——D-来苏糖,其组成摩尔比为L-阿拉伯糖:D-木糖:D-来苏糖:D-甘露糖:D-葡萄糖:D-半乳糖等于1:5:2:28:4:14。 首次采用光散射法（动静态光散射仪）、比旋光度法（自动旋光仪）、热分析仪等测定了ASP的物理性质。用光散射法测定其重均分子量为1.42×10⁵g/mol,比旋光度为+90°,总糖含量96.5%,显色反应表明ASP是还原性多糖,热分析测试为无定型粉末。 2.本文首次采用特异性糖苷酶切技术结合IR、MS、GC、GC-MS、¹³C-CP/MAS NMR、¹³C-NMR、¹H-NMR、¹³C DEPT135 NMR、2D NMR(¹³C-¹H COSY和¹H-¹H COSY)等综合分析了组成ASP单糖的连接顺序及糖苷键类型、分支点,给出了ASP的化学结构。其连接顺序为:葡萄糖（α-1）-甘露糖（β-1,3）-葡萄糖（β-1,4）-木糖（β-1,3）-来苏糖（β-1,5）-葡萄糖（β-1,4）-甘露糖（β-1,3,6）-半乳糖（α-1,2,6）-半乳糖（β-1,6）-木糖（β-1,3）-阿拉伯糖（α-1）,大分支点为葡萄糖的α-1,6连接处,同时甘露糖同糖之间以α-1,2,6、β-1,3,6、β-1,2,3,6方式连接,半乳糖同糖之间以α-1,2,4,6、α-1,2,6方式连接,分别形成许多小的分支。 3.首次采用原子力显微镜和透射电镜,确定了ASP的空间结构。ASP是具有高度分支的线形大分子,ASP单分子直径约为1.2-2.53nm,长链约2435-8560nm,分支约200-2000nm,主链之间、支链之间、主链与支链之间通过大分子间作用力相互扭结、交联形成三维网络结构。 4.首次采用现代药理学方法,以四氧嘧啶诱发的糖尿病实验大鼠为动物模更多还原

【Abstract】 Artemisia seed polysaccharide（ASP）, because of its prominent advantages such as strong hydroscopicity — it can absorb 60 times water as the weight of itself, and the high viscosity — which is 1800 times that of gelatin, can be applied widely in different fields, such as chemical industry, food industry and ecology. However, there is no report of its structure analysis in domestic and abroad until now.1. As reported in 1980, the ASP, which was hydrolyzed by H₂SO₄ and acetyl, was analyzed by PC and Whatman celluose column chromatography. The result showed that ASP was composed of D-Glu, D-Gal, D-Man, L-Ara and D-Xyl. In present study, the acetate derivatives of ASP was determined by means of PC, GC, and GC-MS. ASP liquid hydrolyzed by TFA was analyzed by HPLC and IC, the result showed that, besides of the five monosaccharide as reported, we discovered the sixth monosaccharide—D-Lyx. That is to say, ASP is composed of six monosaccharide, the six monosaccharide are L-Ara, D-Xyl, D-Lyx, D-Man, D-Glu and D-Gal.The molar ration is 1:5:2:28:4:14 respectively.In my study, the physical characteristics of ASP are measured firstly by means of light scatterometer, autopolarimeter and thermoanalyzer. The molecule weight of ASP is 1.42×10⁵g/mol, the specific rotatory power is +90°, and the total content of ASP is 96.5%. The thermal analysis shows that ASP is a amorphism powder.2. The sequence of monosaccharide-linker, the classification of glycosidic bonds and the branches points are analyzed by IR, GC, MS, GC-MS, ¹³C-CP/MAS NMR, ¹³C-NMR, ¹H-NMR, ¹³C DEPT135 NMR, 2D NMR (¹³C-¹H COSY and ¹H-¹H COSY) and the ASP are catalyzed by the specific glycosidase for the first time. The results demonstrated that the sequence of monosaccharide-linker is Glu （α-1） - Man（β-1, 3） -Glu （β-1, 4） -Xyl （β-1, 3） -Lyx （β-1, 5） -Glu （ β-1, 4） -Man（β -1, 3, 6） -Gal （α-1, 2, 6） -Gal （β-1, 6） -Xyl （β-1, 3） -Ara （α-1） .Themajor branches point is a-Glu（l-6）. All Mans are linked in the way as α-1, 2, 6、β -1,3, 6、 and β-1, 2, 3, 6, and all Gals are linked in the way as α-1, 2, 4, 6 、α-1, 2,6. There are many minor branches in the links.3. The images of ASP were studied by means of AFM and TEM for the first time. The research indicated that ASP is a linear macromolecule with many divisions; thediameter of a monosaccharide molecule is about 1.2- 2.53nm, the chain length is about 2435-8560nm, and the branches length is about 200-2000nm. The three-dimensional network structure can be formed by the entanglement and cross-links among the main strains, the branch strains, and the main strains with the branch strains.4. Using the modern pharmacological method, we studied the hypoglycemic influence and mechanism of ASP on blood sugar, serum insulin, serum glucagons, and hepatic glycogen of the alloxan-induced diabetic rats. The results demonstrated that ASP could reduce hyperglycemia, change glucose into glycogen; recover the destructed pancreatic cell, Enhance the physical antioxidant function and protect the hepar and kidney.更多还原