Yasohara Y, Kizaki N, Hasegawa J, Takahashi S, Wada M, Kataoka M, Shimizu S
Fine Chemicals Research Laboratories, Kaneka Corporation, Hyogo, Japan.
Appl Microbiol Biotechnol. 1999 Jun;51(6):847-51. doi: 10.1007/s002530051472.
A total of 400 yeast strains were examined for the ability to reduce ethyl 4-chloroacetoacetate (COBE) to ethyl 4-chloro-3-hydroxybutyrate (CHBE) by using acetone-dried cells in the presence of a coenzyme-recycling system in water/n-butyl acetate. We discovered some yeast strains that reduced COBE to (S)-CHBE. Heating of acetone-dried cells of the selected yeast strains increased the optical purity of the product. There may be several enzymes that can reduce COBE stereoselectively in the same yeast cells. The cultured broth of Candida magnoliae accumulated 90 g/l (S)-CHBE (96.6% enantiomeric excess, e.e.) in the presence of glucose, NADP and glucose dehydrogenase in n-butyl acetate. When these cells were heated, the stereoselectivity of the reduction increased to 99% e.e. (S)-CHBE is one of the useful chiral building blocks applicable to the synthesis of some pharmaceuticals. We expect that the cheap and industrial production of this important chiral compound will follow the discovery of this yeast strain.
总共检测了400株酵母菌株，在水/乙酸正丁酯存在辅酶循环系统的条件下，使用丙酮干燥细胞将4-氯乙酰乙酸乙酯（COBE）还原为4-氯-3-羟基丁酸乙酯（CHBE）的能力。我们发现了一些能将COBE还原为（S）-CHBE的酵母菌株。对所选酵母菌株的丙酮干燥细胞进行加热，提高了产物的光学纯度。在同一酵母细胞中可能存在几种能立体选择性还原COBE的酶。在乙酸正丁酯中，在葡萄糖、NADP和葡萄糖脱氢酶存在的情况下，木兰假丝酵母的培养液积累了90 g/l的（S）-CHBE（对映体过量96.6%，e.e.）。当这些细胞被加热时，还原反应的立体选择性提高到99% e.e. （S）-CHBE是适用于某些药物合成的有用手性砌块之一。我们期望随着这种酵母菌株的发现，这种重要手性化合物能够实现廉价的工业化生产。
