A green-by-design biocatalytic process for atorvastatin intermediate
A green-by-design biocatalytic process for atorvastatin intermediate
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DOI：
10.1039/b919115c
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发表时间：
2010-01-01
期刊：
影响因子：
9.8
通讯作者：
Sheldon, Roger A.
中科院分区：
文献类型：
--
作者：
Ma, Steven K.;Gruber, John;Sheldon, Roger A.
描述了一种绿色设计、两步、三酶工艺的开发，用于合成阿托伐他汀生产中的关键中间体，阿托伐他汀是降胆固醇药物立普妥（R）的活性成分。第一步涉及使用酮还原酶（KRED）与葡萄糖和NADP依赖性葡萄糖脱氢酶（GDH）组合用于辅因子再生的4-氯乙酰乙酸乙酯的生物催化还原。以96%的分离收率和>99.5%的e. e.在第二步中，使用卤代醇脱卤酶（HHDH）通过在中性pH和环境温度下与HCN反应来催化氯取代基被氰基取代。天然酶是高度选择性的，但表现出的生产率是不够的大规模应用。因此，使用基因改组技术的体外酶进化根据预定义的标准和工艺参数来优化其性能。在HHDH反应的情况下，这提供了单位生物催化剂负载的体积生产率的2500倍改进。这使得关键的羟基腈中间体的经济和环境吸引力的生产。当不包括工艺用水时，整个工艺的E因子（kg废物/kg产品）为5.8，如果包括工艺用水，则为18。
The development of a green-by-design, two-step, three-enzyme process for the synthesis of a key intermediate in the manufacture of atorvastatin, the active ingredient of the cholesterol lowering drug Lipitor(R), is described. The first step involves the biocatalytic reduction of ethyl-4-chloroacetoacetate using a ketoreductase (KRED) in combination with glucose and a NADP-dependent glucose dehydrogenase (GDH) for cofactor regeneration. The (S) ethyl-4-chloro-3-hydroxybutyrate product is obtained in 96% isolated yield and >99.5% e. e. In the second step, a halohydrin dehalogenase (HHDH) is employed to catalyse the replacement of the chloro substituent with cyano by reaction with HCN at neutral pH and ambient temperature. The natural enzymes were highly selective but exhibited productivities that were insufficient for large scale application. Consequently, in vitro enzyme evolution using gene shuffling technologies was employed to optimise their performance according to predefined criteria and process parameters. In the case of the HHDH reaction, this afforded a 2500-fold improvement in the volumetric productivity per biocatalyst loading. This enabled the economical and environmentally attractive production of the key hydroxynitrile intermediate. The overall process has an E factor (kg waste per kg product) of 5.8 when process water is not included, and 18 if included.