The Constitution of a Galactomannan from the Seed of Gleditsia amorphoides1
The Constitution of a Galactomannan from the Seed of Gleditsia amorphoides1
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皂荚种子中半乳甘露聚糖的构成1
DOI：
10.1021/jo01014a065
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发表时间：
1965
期刊：
影响因子：
--
通讯作者：
A. Cerezo
中科院分区：
文献类型：
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作者：
A. Cerezo
从皂荚种子中分离得到一种半乳甘露聚糖，其D-半乳糖含量为28.6%，D-甘露糖含量为71.4%，得率为30%。高碘酸盐氧化表明，所有的甘露糖和半乳糖单位被攻击，因为水解的还原氧代多糖只得到甘油（1摩尔）和甘油（2.7摩尔）。对于每四个己糖残基，高碘酸盐消耗为4.8摩尔，同时产生1摩尔甲酸。水解甲基化多糖得到2，3，4，6-四-O-甲基-D-半乳糖（1摩尔）、2，3，6-三-O-甲基-D-甘露糖（2.1摩尔）和2，3-二-O-甲基-D-甘露糖（1.1摩尔）。Riqué和Pardo 28研究了它的果实，发现它的成分与刺槐豆果实相似。由于半乳甘露聚糖种子中所含的工业应用在这个国家不断增加，因此研究其结构是否与已知的半乳甘露聚糖相似是很有意义的。采用热水浸提法从干燥、粗磨的枸杞子中提取枸杞多糖。向水提取物中加入乙醇沉淀多糖（产率30%），为纤维状物质。通过逐步增加乙醇浓度从其水溶液中分级沉淀来纯化该粗产物;在22 - 26%（wt.乙醇/wt.的溶液），在较低或较高浓度（上限50%）下没有获得显著沉淀。在两次再沉淀之后，多糖显示出小于0.4%的氮含量和25 d + 22.4（水）的旋光度。
A galactomannan composed of 28.6% D-galactose and 71.4% D-mannose was isolated in 30% yield from the seeds of Gleditsia amorphoides. Periodate oxidation showed that all the mannose and galactose units were attacked since hydrolysis of the reduced oxopolysaccharidegave only glycerol (1 mole) and erythritol (2.7 moles). The periodate consumption was 4.8 moles for every four hexose residues and at the same time 1 mole of formic acid was produced. Hydrolysis of the methylated polysaccharide yielded 2, 3, 4, 6-tetra-O-methyl-D-galactose (1 mole), 2, 3, 6-tri-O-methyl-D-mannose (2.1 moles), and 2, 3-di-O-methyl-D-mannose (1.1 moles).Gleditsia amorphoides is a leguminous tree that grows in the northern part of the Argentine Republic where it is known as “espina corona’’. Its fruit has been studied by Riqué and Pardo28 who showed that its composition was similar to that of locust bean fruit. 28 As the indus-trial applications of the galactomannan contained in its seed are continually increasing in thiscountry it was of interest to study whether its structure is similar to those of the already known galactomannans. The polysaccharide was extracted from the dry and coarsely ground seed with hotwater. Addition of ethanol to the aqueous extract precipitated the poly-saccharide (yield 30%) as a fibrous material. This crude product was purified by fractional precipitation from its aqueous solution by increasing the concentra-tion of ethanol stepwise; nearly 90% of the initial weight precipitated at an ethanol concentration between 22 and 26%(wt. of ethanol/wt. of solution), no significant precipitation was obtained at lower or higher concentration (upper limit 50%). After two reprecipitations the polysaccharide showed a nitrogen content of less than 0.4% and a rotatory power of [«] 25d-+ 22.4 (water).