Fine structure of polysaccharides obtained from dietary fibers.

从膳食纤维生理功能的角度出发，阐明细胞壁多糖的结构和性质具有重要意义。在本研究项目中，我们取得了以下成果。(1)比较了叶菜类（卷心菜、菠菜、生菜和生菜）和根菜类（芜菁、日本萝卜、牛蒡、胡萝卜和东印度莲）的碳水化合物在冷冻干燥的样品中的含量。碳水化合物的分级，和糖组成的糖键组成分析的馏分表明，它们的基本组成多糖几乎是相同的。细胞壁由具有侧链的鼠李糖半乳糖醛酸聚糖、（1->5）-连接的阿拉伯聚糖、（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24%KHO牛蒡提取物中分离得到一种木葡聚糖。甲基化分析和酶降解研究表明，魔芋木葡聚糖是一种具有生物活性的多糖， ...更多信息 主要是七-（Glc：Xyl=4：3）、九-（Glc：Xyl：Gal：Fuc=4：3：1：1）和十-（Glc：Xyl：Gal：Fuc =4：3：2：1）葡聚糖的重复寡糖单元，摩尔比约为14：12：5，它们是双子叶木葡聚糖的典型结构单元。(3)比较了甘蓝、菠菜、生菜、青根菜等植物中木葡聚糖的化学结构。它们的基本结构几乎相同。(4)牛蒡中的菊糖在贮藏或加热过程中被酶在体内水解为低分子量碳水化合物。(5)随着水不溶性膳食纤维浓度的增加，葡萄糖的体外扩散速度降低。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)从霍霍巴船体中分离得到一种葡糖醛酸木聚糖。对霍霍巴船体木聚糖的甲基化分析和酶降解研究表明，霍霍巴木聚糖的主链为（1->4）-D-木糖基直链，其中约13%在0-2位有支链，4-0-甲基-α-D-吡喃葡萄糖醛酸残基。（P.T.O.）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