Fine structure of polysaccharides obtained from dietary fibers.

从膳食纤维的生理功能角度出发，阐明细胞壁多糖的结构和性质具有重要意义。在这个研究项目中，我们得到了以下结果。(1)比较了叶片类蔬菜（白菜、大白菜、菠菜、青菜和莴苣）和块根类蔬菜（芜菁、萝卜、食用牛蒡、胡萝卜和东印度莲）的碳水化合物含量。碳水化合物的分馏、糖组成和糖链组成分析表明，它们的基本成分多糖几乎相同。细胞壁由带侧链的鼠李糖半乳糖酸、（1-> - 5）连接的阿拉伯糖、（1-> - 4）连接的半乳聚糖、阿拉伯半乳聚糖、木葡聚糖和纤维素组成。(2)从食用牛蒡24% KHO提取物中分离得到木葡聚糖。甲基化分析和酶降解多糖研究表明gobo-xyloglucan建成 ... 更主要的repeating-oligosaccharide七-单位(相关:Xyl = 4: 3),诺娜-(相关:Xyl:女孩:Fuc = 4: 3: 1: 1)和十-(相关:Xyl:女孩:Fuc = 4: 3: 2: 1)糖类的近似克分子比14:12:5,双子叶植物的典型结构单元xyloglucans。(3)比较了白菜、大白菜、菠菜、青菜和莴苣中木葡聚糖的化学结构。它们的基本结构几乎相同。(4)食用牛蒡中的菊粉在贮藏或加热过程中被酶水解，生成低分子量的碳水化合物。(5)随着水不溶性膳食纤维浓度的增加，体外葡萄糖扩散速度降低。这被认为是由于水不溶性膳食纤维对低分子量碳水化合物的渗透性。(6)从荷荷巴壳中分离到一种葡萄糖醛酸氧酶。甲基化分析和酶降解研究表明，荷荷巴壳木聚糖在主链上具有(1- bbbb4)- d -木糖基残基的线性链，其中约13%的残基在0-2位支链，为4-0-甲基- α - d -葡萄糖醛酸残基。少

From the viewpoint of the physiological function of dietary fiber, it is important to elucidate the structure and properties of cell wall polysaccharides. In this research project, we obtained the following results.(1) Carbohydrates in leaf vegetables (cabbage, chainease cabagge, spinach, chingentsuai and lettuce) and root vegetables (turnip, japanese radish, edible burdock, carrot and east indian lotus) were compared in triturated, freeze-dried samples. Fractionation of the carbohydrates, and the sugar composition an sugar-linkage composition analyzes of the fractions suggested that their basic constituent polysaccharides were almost the same. The cell walls consisted of rhamnogalacturonan with side chains, (1->5)-linked arabinan, (1->4)-linked galactan, arabinogalactan, xyloglucan and cellulose.(2) A xyloglucan was isolated from 24% KHO extract of gobo (edible burdock). A methylation analysis and enzymic degradation studies on the polysaccharide showed that gobo-xyloglucan was built … More up predominantly of repeating-oligosaccharide units of hepta-(Glc : Xyl=4 : 3), nona-(Glc : Xyl : Gal : Fuc=4 : 3 : 1 : 1) and deca-(Glc : Xyl : Gal : Fuc=4 : 3 : 2 : 1)saccharides in an approximate molar ratio of 14 : 12 : 5, which are the typical structural units of dicot xyloglucans.(3) The chemical structures of xyloglucans obtained from cabbage, chainease cabagge, spinach, chingentsuai and lettuce were compared. Their basic structures were almost the same.(4) Inulin in edible burdock was hydrolyzed in vivo by enzyme(s) to yield lower molecular weight carbohydrates during storage or heating.(5) The glucose diffusion speed decreased in vitro as the concentration of the water insoluble dietary fiber increased. This was considered to be due to the permiability of the water-insoluble dietary fiber to lower-molecular weight carbohydrates.(6) A glucuronoxylan was isolated from jojoba hull. Methylation analysis and enzymic degradation studies of the polysaccharide showed that jojoba hull xylan has a linear chain of (1->4)-D-xylosyl residues in the backbone, about 13% of which are branched at 0-2 position, with 4-0-methyl-alpha-D-glucopyranosyluronic acid residues.(P.T.O.) Less