Deracemization of (±)-2,3-disubstituted oxiranes via biocatalytic hydrolysis using bacterial epoxide hydrolases: kinetics of an enantioconvergent process
Deracemization of (±)-2,3-disubstituted oxiranes via biocatalytic hydrolysis using bacterial epoxide hydrolases: kinetics of an enantioconvergent process
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使用细菌环氧化物水解酶通过生物催化水解实现 (±)-2,3-二取代环氧乙烷的去消旋化：对映体收敛过程的动力学
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
K. Faber
中科院分区：
文献类型：
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作者：
W. Kroutil;M. Mischitz;K. Faber
通过利用各种细菌菌株的环氧化物水解酶活性，实现了 (±)-2,3-二取代环氧乙烷的不对称生物催化水解，从而在 100% 转化率下形成了高达 97% ee 的邻位二醇。使用来自诺卡氏菌 EH1 的部分纯化的环氧化物水解酶进行 18OH2 标记实验，阐明了这种去消旋作用的机制。该反应通过 OH- 攻击 (S) 构型环氧乙烷碳原子并伴随构型反转，以对映体收敛方式进行。通过确定控制过程的区域选择性和对映选择性的四个相对速率常数，验证了为描述动力学而开发的数学模型。
Asymmetric biocatalytic hydrolysis of (±)-2,3-disubstituted oxiranes leading to the formation of vicinal diols in up to 97% ee at 100% conversion was accomplished by using the epoxide hydrolase activity of various bacterial strains. The mechanism of this deracemization was elucidated by 18OH2-labelling experiments using a partially purified epoxide hydrolase from Nocardia EH1. The reaction was shown to proceed in an enantioconvergent fashion by attack of OH– at the (S)-configured oxirane carbon atom with concomitant inversion of configuration. A mathematical model developed for the description of the kinetics was verified by the determination of the four relative rate constants governing the regio- and enantio-selectivity of the process.