Peroxyacid synthesis is the first step in Prilezhaev epoxidation, which is an industrial method to form epoxides. Motivated by the development of a kinetic model as a tool for solvent selection, the effect of solvent type and acid chain length on the lipase-catalyzed peroxyacid synthesis was studied. A thermodynamic activity-based ping-pong kinetic expression was successfully applied to predict the effect of the reagent loadings in hexane. The activity-based reaction quotients provided a prediction of solvent-independent equilibrium constants. However, this strategy did not achieve satisfactory estimations of initial rates in solvents of higher polarity. The lack of compliance with some assumptions of this methodology could be confirmed through molecular dynamics calculations i.e. independent solvation energies and lack of solvent interaction with the active site. A novel approach is proposed combining the activity-based kinetic expression and the free binding energy of the solvent with the active site to predict kinetics upon solvent change. Di-isopropyl ether generated a strong interaction with the enzyme's active site, which was detrimental to kinetics. On the other hand, toluene or limonene gave moderate interaction with the active site rendering improved catalytic yield compared with less polar solvents, a finding sharpened when peroctanoic acid was produced.

中文翻译：

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通过基于活性的动力学和分子动力学阐明溶剂对脂肪酶催化过氧酸合成的影响


过氧酸合成是Prilezhaev环氧化的第一步，Prilezhaev环氧化是形成环氧化物的工业方法。在开发动力学模型作为溶剂选择工具的推动下，研究了溶剂类型和酸链长度对脂肪酶催化过氧酸合成的影响。基于热力学活动的乒乓动力学表达式已成功应用于预测己烷中试剂负载的影响。基于活性的反应商提供了与溶剂无关的平衡常数的预测。然而，该策略并未对较高极性溶剂中的初始速率实现令人满意的估计。不符合该方法的一些假设可以通过分子动力学计算来确认，即独立的溶剂化能和缺乏溶剂与活性位点的相互作用。提出了一种新方法，将基于活性的动力学表达式和溶剂与活性位点的自由结合能结合起来，以预测溶剂变化时的动力学。二异丙醚与酶的活性位点产生强烈的相互作用，这不利于动力学。另一方面，与极性较小的溶剂相比，甲苯或柠檬烯与活性位点产生适度的相互作用，从而提高了催化产率，这一发现在生产过辛酸时更加明显。