双组分混合有机溶剂中脂肪酶催化反应的热力学分析

将两种不同极性的有机溶剂1,4-二氧六环和正庚烷按不同摩尔比混合，配成具有不同logP值的双组分混合溶剂，以此为反应介质考察了固定化脂肪酶Lipozyme RM IM催化的正丁醇和月桂酸酯化反应的初速度. 同时在与上述混合溶剂具有相近logP值的单一溶剂中进行了类似研究. 实验结果表明，在混合溶剂和单一溶剂中，反应初速度随溶剂极性的变化规律呈现很大差异. 从溶剂混合对反应物热力学活度及反应活化能的影响可以合理地解释这一实验结果.

Thermodynamic Analysis of Lipase-catalysed Esterification in Binary Organic Solvent Mixtures

Two kinds of miscible organic solvents with marked discrepancy m polarity, 1,4-dioxane and heptane, were mixed at different mole proportions to create a series of binary solvent mixtures with different logP values. Lipozyme RM IM-catalysed esterification between 1-butanol and laurie acid in such binary solvent mixtures as well as singular solvents with corresponding polarities was comparatively investigated. The variation of enzyme activity calibrated by initial rate of esterification with the decrease of solvent polarity in solvent mixtures and singular solvent was compared, and different variation tendencies were observed. Based on the results in the effect of the solvent mixture on the thermodynamic activities of reactants, the activation energies of reactions were proposed to rationally explain the phenomena observed in the esterification.