酶促酯交换反应常用于改善酚酸的亲脂性。本研究采用酶促酯交换策略，将脂肪酸链以羧基的形式引入对香豆酸中，成功地在非水介质中合成了一系列新的对香豆酸衍生物。在最佳反应条件下，脂肪酶Nov.435 40 mg/mL，溶剂为吡啶:环己烷=1:9，底物摩尔比=1:10，温度50 ℃，转速180 r/min，对香豆酸甲酯的转化率可达98%。进一步的研究表明，20 μM时p-CA对DPPH自由基（醇溶体系）的清除活性为56.34%，对香豆酸月桂酯、对香豆酸癸酯、对香豆酸辛酯、对香豆酸己酯、对香豆酸丁酯和TBHQ在相同浓度下对DPPH自由基的清除活性分别为73.91%、70.32%、68.90%、60.62%、43.65%和67.51%。其中，对香豆酸月桂酯的DPPH自由基清除活性明显高于p-CA和TBHQ，但低于Trolox。结论：非水相酶促合成的不同链长对香豆酸酯具有良好的清除自由基能力。因此，合成的具有不同抗氧化活性的酯类衍生物有望应用于不同的食品、药物和化妆品体系中，为酯类衍生物的合成提供有益的指导。

Enzymatic transesterification is often used to improve the lipophilicity of phenolic acids. In this study, a series of new derivatives of p-coumaric acid were successfully synthesized in non-aqueous medium by introducing fatty acid chain into p-coumaric acid in the form of carboxyl group by enzymatic transesterification strategy. Under the optimal reaction conditions: the lipase NOV.435 of 40 mg/mL, the solvent of pyridine: cyclohexane of 1:9, the molar ratio of substrate of 1:10, temperature of 50 ℃, the rotation speed of 180 r/min, the conversion rate was reached to 98%. In addition, further study showed that the scavenging activity of p-Ca against DPPH radical (alcohol-soluble system) was 56.34% at 20 μM, and the scavenging activity against DPPH radical of lauryl coumarate, p-decyl coumarate, p-octyl coumarate, p-hexyl coumarate, p-butyl coumarate and TBHQ at the same concentration was 73.91%, 70.32%, 68.90%, 60.62%, 43.65% and 67.51%, respectively. Obviously, the scavenging activity of laurel ester against coumarate was higher than those of p-Ca and TBHQ. Conclusion: coumarate has good free radical scavenging ability by enzymatic synthesis of different chain lengths in non-aqueous phase. Therefore, the synthesized ester derivatives with different antioxidant activities will be expected to be used in different food, drug and cosmetic systems, and provide beneficial guidance for the synthesis of ester derivatives.

国家自然科学基金资助项目(21978101)；广州市科技计划民生科技项目(201803020031)