Determination of the degree of methyl esterification of pectins in small samples by selective reduction of esterified galacturonic acid to galactose.
Determination of the degree of methyl esterification of pectins in small samples by selective reduction of esterified galacturonic acid to galactose.
复制标题
通过将酯化半乳糖醛酸选择性还原为半乳糖来测定小样品中果胶的甲酯化程度。
DOI：
10.1016/0003-2697(90)90306-t
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发表时间：
1990
影响因子：
2.9
通讯作者：
A. Mort
中科院分区：
文献类型：
--
作者：
N. Maness;J. D. Ryan;A. Mort
描述了一种测定几乎任何样品中果胶甲酯化度的方法。样品在1M咪唑缓冲液中溶解或悬浮，pH 7.0，冰上冷却，用硼氢化钠还原。用至少20毫克的硼氢化钠/毫克样品，在1小时后完成样品的定量还原。甲酯化程度是由糖的GLC测定的半乳糖含量的增加或由糖醛酸比色分析测定的半乳糖醛酸量的变化来确定的。样品要求至少低至100GLC每次测定或2至3毫克的比色糖醛酸分析，相比之下，其他已发表的方法每次测定5毫克或更多。用所述方法测定的甲酯化度与已有方法测定的甲酯化度进行了比较，结果令人满意。
A procedure for the determination of the degree of methyl esterification of pectin in virtually any sample is described. Samples were dissolved or suspended in 1 m imidazole buffer, pH 7.0, cooled on ice, and reduced with sodium borohydride. Quantitative reduction of samples was accomplished after 1 h using at least 20 mg sodium borohydride/mg sample. The degree of methyl esterification was determined by either the increase in galactose content as determined by GLC of the sugar or by the change in galacturonic acid content by colorimetric uronic acid analyses. Sample requirements were at least as low as 100 μg per determination by GLC or 2 to 3 mg per determination by colorimetric uronic acid analysis compared to 5 mg or more per determination for other published procedures. The degrees of methyl esterification determined by the methods described have compared very favorably with those determined by established methods.