화학공학소재연구정보센터
Process Biochemistry, Vol.47, No.3, 517-522, 2012
Chemoenzymatic epoxidation of citronellol catalyzed by lipases
The chemoenzymatic epoxidation of a terpene alcohol, citronellol, is reported. Some experimental conditions, such as the use of lipases from different sources, oxidizing agents (H2O2 or urea-hydrogen peroxide, UHP), reaction time, acyl donor type (C6-C16), temperature (15-40 degrees C) and the influence of organic media, were evaluated. In most cases, citronellol oxide 2 or the ester citronellol oxide 3 were obtained. Depending on the reaction conditions, high yields of products 2 or 3 were obtained (>99%). CAL-B was the most effective catalyst in this reaction. For epoxide 2. the highest yields of 80% and 77% were obtained at 20 degrees C and 25 degrees C. respectively, using UHP as an oxidizing agent and octanoic acid as an acyl donor. The organic medium appears to be one of the most important parameters in the reaction. Using chloroform or dichloromethane, product 2 was obtained at a >99% yield after 24 h. When different mixtures consisting of varied organic solvents and an imidazolium-based ionic liquid (IL) were used, the results were dependent on both the solvent and IL counter-ion (18-75%). (C) 2012 Elsevier Ltd. All rights reserved.