ON THE MECHANISM OF THIAMINE ACTION .4. EVIDENCE FROM STUDIES ON MODEL SYSTEMS
ON THE MECHANISM OF THIAMINE ACTION .4. EVIDENCE FROM STUDIES ON MODEL SYSTEMS
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DOI：
10.1021/ja01547a064
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发表时间：
1958-01-01
影响因子：
15
通讯作者：
BRESLOW, R
中科院分区：
文献类型：
--
作者：
BRESLOW, R
OH OH这些反应都有一个共同的特点，即它们可以被认为涉及形成中间体酰基碳负离子，R-CO（-），或一些稳定的等价物。这种类型的中间体被称为“活性醛”。3关于硫胺素在促进这些反应中的可能作用，已经有几种建议。最早的提议之一是Langenbeck的提议，他特别考虑了将甘草酸脱羧为乙醛。他指出[4]硫胺素的氨基与异烟酸缩合形成席夫碱Ha，该席夫碱Ha脱羧生成乙醛的席夫碱lib，后者化合物然后水解成游离醛和再生的硫胺素。
OH OH These reactions all have one common feature in that they can be considered to involve the formation of an intermediate acyl carbanion, R-CO (—), or some stabilized equivalent. This type of intermediate has been called an “active aldehyde.” 3 There havebeen several suggestions as to the possible role ofthiamine in facilitating these re-actions. One of the earliest proposals was that of Langenbeck, who considered in particular the de-carboxylation of pyruvic acid to acetaldehyde. He suggested4 that the amino group of thiamine con-denses with pyruvic acid to form a Schiff base Ha which decarboxylates to the Schiff base of acetaldehyde lib, this latter compound then hydrolyzing to the free aldehyde and regenerated thiamine.