ABSTRACT Medium- and long-chain triacylglycerols (MLCTs) with high 1,3-oleic-2-medium chain (OMO) triacylglycerols content were synthesized by the acidolysis reaction between Cinnamomum camphora seed oil (CCSO) and oleic acid, catalyzed by lipozyme RM IM. In addition, the simultaneous rate of acyl migration (RAM) was investigated during the esterification process. The maximal yield of OMO-structured triacylglycerols (YST) was up to 64.45% under the optimum condition: the molar ratio of CCSO to oleic acid, 1:4; enzyme dosage, 10 wt%; temperature, 60°C; and reaction time, 24 h. RAM was 28.66% at same time. It is shown that YST positively related to RAM at single experiments of the molar ratio (r2 = 0.999, P< .01), enzyme dosage (r2 = 0.988, P< .01), below 60°C of temperature (r2 = 0.923, P< .05) and within 24 h of reaction time (r2 = 0.940, P< .05). However, YST was negatively correlated with RAM at a temperature higher than 60°C (r2 = −0.682, P> .05) or a reaction time longer than 24 h (r2 = −0.594, P> .05). The effect of temperature on the reaction could be verified by molecular dynamics simulation, opened enzyme lids were increased with temperature elevated, and helped substrates invade into catalytic triad. When temperature rose to higher than 333 K (60°C), rearrangement of the catalytic triad was promoted, which resulted in both decreasing enzyme catalytic activity and irritating acyl migration. This study could help understand the trigger cause of acyl migration at high temperature, and conclusively reaction temperature was a vital factor to balance YST and RAM in a solvent-free system. OMO-structured triacylglycerols might possess a potential application as a new type of nutritional lipids for daily diet. TOC graphic Enzymatic Synthesis of 1,3-oleic-2-medium Chain Triacylglycerols and Strategy of Controlling Acyl Migration: Insights from Experiment and molecular dynamics simulation

中文翻译：

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1,3-油酸-2-中链三酰甘油的酶促合成和控制酰基迁移的策略：来自实验和分子动力学模拟的见解

摘要 通过樟脑油 (CCSO) 和油酸在脂酶 RM 催化下的酸解反应合成了具有高 1,3-油酸-2-中链 (OMO) 三酰甘油含量的中长链三酰甘油 (MLCT)我是。此外，还研究了酯化过程中酰基迁移的同步速率 (RAM)。在CCSO与油酸的摩尔比为1:4的最佳条件下，OMO结构的三酰基甘油(YST)的最大产率可达64.45%；酶用量，10 wt%；温度，60°C；和反应时间，24 小时。RAM 同时为 28.66%。结果表明，在摩尔比 (r2 = 0.999, P< .01)、酶用量 (r2 = 0.988, P< .01)、温度低于 60°C (r2 = 0.923) 的单个实验中，YST 与 RAM 呈正相关, P< .05) 和反应时间的 24 小时内 (r2 = 0.940, P < .05）。然而，当温度高于 60°C（r2 = -0.682，P> .05）或反应时间超过 24 小时（r2 = -0.594，P> .05）时，YST 与 RAM 呈负相关。温度对反应的影响可以通过分子动力学模拟得到验证，打开的酶盖随温度升高而增加，并有助于底物侵入催化三联体。当温度升至高于 333 K (60°C) 时，催化三联体的重排被促进，导致酶催化活性降低和酰基迁移刺激。该研究有助于了解高温下酰基迁移的触发原因，最终反应温度是在无溶剂系统中平衡 YST 和 RAM 的重要因素。OMO 结构的三酰基甘油作为一种新型的日常饮食营养脂质可能具有潜在的应用价值。TOC 图形酶法合成 1,3-油酸-2-中链三酰甘油和控制酰基迁移的策略：来自实验和分子动力学模拟的见解