反应条件对脂肪酶酯化活性和对映选择性的影响Effect of Reaction Parameters on Reactivity and Enantioselectivity of Lipase-catalyzed Esterification
刘幽燕,许建和,刘洪来,胡英
摘要(Abstract)：
分别测定了2-萘基丙酸类药物萘普生R-、S-对映体在有机溶剂中的酶促酯化反应初速度，并研究了反应温度、酰基受体和有机溶剂等反应条件对脂肪酶的反应活性和对映选择性的影响。在一定范围内，酶反应活性随温度升高而增加，温度过高易使酶失活；酶选择性则随温度升高而下降；反应温度以35～40℃为佳。在疏水性强的溶剂中，酶反应活性较大；酶的选择性则以异辛烷、苯、甲苯等为溶剂时较好。合适的混合溶剂系统能使酶表现出比在单一溶剂中更好的活性和选择性；这与外消旋萘普生的实际酶促拆分结果是一致的。
关键词(KeyWords)： 脂肪酶;活性;对映选择性;萘普生;酯化反应
基金项目(Foundation): 国家自然科学基金!29506043
作者(Author): 刘幽燕,许建和,刘洪来,胡英
参考文献(References)：
- [1]Chen C S Wu S H,Girdaukas G,Sih C J Quantitative analyses of biochemical kinetic resolution of enantiomers.2. Enzyme-catalyzed esterification in water-organic solvent biphasic systems[J]J Am Chem Soc, 1987, 109: 2812-2817.
- [2]Gu Q M, Chen C S,Sih C J.A facile enzymatic resolution process for thepreparation of(+)- S-2-(6-methoxt-2- naphthyl)Propionic acid(Naproxen)[J].Tetrahedron letters,1986,27:1763-1767.
- [3]Tsai S W,Wei H J. Effect of solventon enantioselective esterification of Naproxen by lipase with trimethylsilyl methanol[J] Biotechnol Bioeng, 1994, 43: 64-68.
- [4]Philips R S.The effects on stereochemistry of enzymatic reactions[J].Enzyme Microb Technol,1992,18:417- 419
- [5]Gormen L A S,Dordick J S.Organic solvents strip water off enzymes [J].Biotechnol Bioeng,1992,39:392-397.
- [6]Laane C,Boeren S,Vos K,Veeger C.Rule for optimization of biocatalysis in organic solvents [J].Biotechnol Bioeng, 1987, 30: 81-87
- [7]Ueji S, Fujio R,Okubo N.Solvent-induced inversion of enantioselectivity in lipase-catalyzed esterification of 2- phenoxypropionic acids[J].Biotechnol Lett,1992,14:163-166.
- [8]Secundo F Riva S Carrea G Effect of medium and of reaction conditions on the enantioselectivity of lipases in organic solvents and possible rationales[J].Tetrahedron:Asymmetry, 1992, 3: 267-269.
- [9]Wescott C R,Klibanov A M.Rational control of enzymatic enantioselectivity through solvation thermodynamics [J]J Am Chem Soc,1996,118:10365-10370.
- [10] Ke T,Wescott C R,Klibanov A M.Prediction of the solvent dependence of enzymatic prochiral selectivity by means of structure-based thermodynamic calculations[J]J Am Chem Soc,1996,118:3366-3374.