STRUCTURE REACTIVITY RELATIONS FOR THIOL DISULFIDE INTERCHANGE
STRUCTURE REACTIVITY RELATIONS FOR THIOL DISULFIDE INTERCHANGE
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DOI：
10.1021/ja00256a040
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发表时间：
1987-10-28
影响因子：
15
通讯作者：
WHITESIDES, GM
中科院分区：
文献类型：
--
作者：
HOUK, J;WHITESIDES, GM
测定了 36 种二硫醇和三硫醇以及衍生自 2-巯基乙醇或二硫苏糖醇的二硫化物之间的硫醇-二硫化物交换的平衡常数。反应在甲醇-d4/水性缓冲液(pH 7)或甲醇-d4中在25℃下进行。 C，使用核磁共振波谱来跟踪反应。这些数据用于根据还原电位对二硫醇进行排序，并推断它们在氧化时形成的二硫化物的结构。二硫醇的还原能力与氧化时形成的含二硫化物环的大小之间存在一般相关性：形成六元环的二硫醇还原性最强（相对于氧化的2-巯基乙醇，K = 103-105 M）；五元环和七元环的还原性大约低1个数量级。类似于 1,2-乙二硫醇的化合物在相对稀的溶液（约 1 mM）中形成环状双（二硫化物）二聚体，但在较高浓度下聚合。其他类别的二硫醇在氧化时形成聚合物。
Equilibrium constants were determined for thiol-disulfide interchange between 36 di- and trithiols and disulfides derived from either 2-mercaptoethanol or dithiothreitol. Reactions were conducted in methanol-d4/squeous buffer (pH 7) or methanol-d4 at 25.degree. C, using NMR spectroscopy to follow the reactions. These data were used to rank the dithiols in terms of reduction potential and to infer the structure of the disulfides formed from them on oxidation. There is a general correlation between the reducing ability of the dithiol and the size of the disulfide-containing ring formed on oxidation: dithiols that form six-membered rings are most strongly reducing (K = 103-105 M with respect to oxidized 2-mercaptoethanol); five- and seven-membered rings are approximately 1 order of magnitude less reducing. Compounds resembling 1,2-ethanedithiol form cyclic bis(disulfide) dimers in relatively dilute solutions (.apprx. 1 mM) but polymerize at higher concentrations. Other classes of dithiols form polymers on oxidation.