Kositawattanakul T, Tosukhowong P, Vimokesant S L, Panijpan B
Am J Clin Nutr. 1977 Oct;30(10):1686-91. doi: 10.1093/ajcn/30.10.1686.
Bio Rex 70 column chromatography and high voltage paper electrophoresis were used to fractionate and define the reaction products of thiamin-tannic acid and thiamin-tea mixtures. Fractions separated indicated the presence of (a) thiamin-tannic acid adduct(s) and several modified forms of thiamin among the products. Using radioactive thiamin and determining the intact form by scintillation counting, the extent of thiamin modification under various conditions was compared with previous results as determined by the thiochrome method. The elution profile of the thiamin-tea mixture and the electrophoretogram showed features similar to those of the thiamin-tannic acid mixture. The effectiveness of the tea extract and tannic acid in modifying thiamin was compared. Ascorbic acid was found to protect the modification of thiamin by tannic acid, not only at acidic pH as previously found, but also at neutral pH, thus making vitamin C a strong candidate for the protection of thiamin in the alimentary system.
使用Bio Rex 70柱色谱法和高压纸电泳法对硫胺素 - 单宁酸混合物和硫胺素 - 茶混合物的反应产物进行分离和鉴定。分离出的馏分表明产物中存在（一种）硫胺素 - 单宁酸加合物和几种硫胺素的修饰形式。使用放射性硫胺素并通过闪烁计数确定完整形式，将各种条件下硫胺素的修饰程度与之前通过硫色素法测定的结果进行比较。硫胺素 - 茶混合物的洗脱图谱和电泳图显示出与硫胺素 - 单宁酸混合物相似的特征。比较了茶提取物和单宁酸对硫胺素的修饰效果。发现抗坏血酸不仅如之前所发现的那样在酸性pH下，而且在中性pH下也能保护硫胺素不被单宁酸修饰，因此使维生素C成为在消化系统中保护硫胺素的有力候选者。
