有机相脂肪酶催化合成阿魏酸乙酯

本实验研究了有机溶剂中脂肪酶催化阿魏酸乙酯合成反应。对催化合成阿魏酸乙酯反应的脂肪酶和反应介质进行了比较,最佳溶剂为叔丁醇,在所选的6种脂肪酶中,固定化于大孔丙烯酸树脂的南极假丝酵母脂肪酶B(Novozym 435)的催化活性最好。同时对影响合成阿魏酸乙酯反应的因素(底物浓度、底物摩尔比、温度、初始水含量、反应时间等)进行了探讨,优化了反应条件:在10ml无水叔丁醇中,当酸醇摩尔比为1:1,酸浓度为0.1mol/L,反应温度为60℃,反应时间为120h时产率达到最高,脂肪酶Novozym 435具有较高的稳定性,重复使用六次后产率仍然可达到23%。

Lipase Catalyzed Synthesis of Ethyl Ferulate in Organic Medium

Esterification of ferulic acid(4-hydroxy-3-methoxy cinnamate)and ethanol in organic solvent with lipase was studied.Six commercially available lipases were screened for their ability to esterify ferulic acid.The best solvent is tert-butyl alcohol and Novozym 435(immobilized on a macroporous acrylic resin)was found to be the best lipase to convert ferulic acid to ethyl ferulate for this reaction system.The influences of the concentration of substrates,the molar ratio of substrates,the temperature of reaction,the amount of water in the medium,and the time of reaction were studied in detail.The optimization of reaction conditions was obtained.In the 10 ml of tert butyl alcohol containing 0% of water(V/V),when the molar ratio of acid to alcohol is 1:1,the temperature is 60 ℃,the concentration of ferulic acid is 0.1 mol/L,the reaction time is 120h,the highest percentage yield was obtained.Novozym 435 has a high stability.A yield of 23% for ethyl ferulate can be obtained with Novozym 435 even after it was used continuously six times.