Enantioselective transesterifi cation of N-hydroxymethyl vince lactam catalyzed by lipase under ultrasound irradiation

Ultrasound has been successfully used to improve the performance of Mucor miehei lipase (MML) in enantioselective transesterifi cation of N-hydroxymethyl vince lactam with vinyl valerate as acyl donor in methyl tert-butyl ether. The effects of reaction conditions have been investigated. Under the optimum conditions (ultrasound power, 175 W; temperature, 30 degrees C; water activity, 0.22; pH, 7.0), the enzyme activity of MML was 93.7 mu mol/g/min and the enantioselectivity (E value) was 68.2. The results also indicated that the free enzyme was stable under low power ultrasound conditions.