Lipase-catalyzed enantioselective esterification of ibuprofen in organic solvents under controlled water activity
Lipase-catalyzed enantioselective esterification of ibuprofen in organic solvents under controlled water activity
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DOI：
10.1016/s0141-0229(97)00180-4
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发表时间：
1998-03-01
影响因子：
3.4
通讯作者：
Lortie, R
中科院分区：
文献类型：
--
作者：
Ducret, A;Trani, M;Lortie, R
假丝酵母菌催化布洛芬（2-（4-异丁基苯基）丙酸）的对映选择性酯化反应。在各种有机溶剂中进行Anastritica脂肪酶（B型）。反应在受控的水活性气氛中进行，从而允许将溶剂的影响与它们从固体酶中剥离水的能力分开。即使在这些恒定的水活性条件下，疏水性溶剂也比亲水性溶剂允许更高的酶活性，这表明亲水性溶剂本质上阻碍酶活性，而不是因为它们从酶中剥离水。不同的性质被用来描述溶剂，即疏水性，量化的log P; ε，介电常数：和E-T（N），归一化的电子接受指数。没有给出一个清晰的和预测的肖像的溶剂的影响，然而，疏水性是最令人满意的。这可能与布洛芬的溶解度，这与log P的值呈线性变化。最高的对映选择性在低水活度观察。这是由于水活度对两种异构体反应速率的不同影响所致。当a（W）降低时，对较不受欢迎的一种异构体的活性在达到最大值后下降，而对另一种异构体的速率继续上升。(C)1998年爱思唯尔科学公司
The enantioselective esterification or ibuprofen (2-(4-iso-butylphenyl)propionic acid), catalyzed by Candida. antarctica lipase (type B), was performed in various organic solvents. The reactions were conducted in controlled water activity atmospheres, thereby permitting the influence of the solvents to be separated from their ability to strip water from the solid enzymes. Even in these constant water activity conditions, hydrophobic solvents allow higher enzyme activity than hydrophilic ones, indicating that hydrophilic solvents impede enzyme activity in essence and not because they strip water from the enzyme. The highest enantioselectivity was obtained in solvents leading to low reaction rates.Different properties were used to describe the solvents, namely the hydrophobicity, quantified by log P; epsilon, the dielectric constant: and E-T(N), a normalized electron acceptance index. None gave a clear and predictive portrait of the influence of the solvent, however, the hydrophobicity was the most satisfactory. This could be linked to the solubility of ibuprofen, which varies linearly with the value of log P.The highest enantioselectivity was observed at low water activities. This is caused by different effects of water activity on the reaction rates with the two isomers. The activity toward the less favored one decreased after reaching a maximum while the rate with the other isomer continued to rise when a(W) decreased. (C) 1998 Elsevier Science Inc.