摘要
脂肪酶主要催化醇、酸、内酯的酯化反应,脂肪酶催化反应可在非水溶剂中进行,并且反应条件温和,被认为是制备单一对映异构体的有效方法。文中利用固定化脂肪酶Novozym 435催化3-TBDMSO戊二酸酐不对称醇解制备3-TBDMSO戊二酸甲酯,通过高效液相色谱考察了不同反应条件对底物转化率、产物选择性的影响规律。实验研究了四氢呋喃、乙酸乙酯、乙醚、甲基叔丁基醚和甲苯5种溶剂对酶催化反应的影响,结果表明:在甲基叔丁基醚溶剂中,Novozym 435的催化效果最好。最优反应条件:温度25℃,酶质量浓度30 mg/mL,醇与3-TBDMSO戊二酸酐摩尔比1.0,酸酐浓度100 mmol/L,pH值为6.5,水活度0.66,反应时间6 h。实验采用萃取的方法分离出反应产物,通过结晶纯化得到无色晶体,利用核磁氢谱证明产物为3-TBDMSO戊二酸甲酯,通过圆二色光谱说明合成产物为对映体过剩产品。
Lipase-catalysed reactions were considered as an effective method to prepare pure enantiomers,based on the esterification of alcohol,acid,or lactone in non-aqueous phase under mild reaction conditions.An enzymatic alcoholysis of 3-(tert-butyldimethylsilyloxy ) glutaric anhydride (3-TBDMSO-GA ) with methanol for preparing 3-(tert-butyldimethylsilyloxy)glutaric methyl monoester (3-TBDMSO-GMM)was studied using immobilized Lipase Novozym 435 .The different solvents including tetrahydrofuran,ethyl acetate,diethyl ether,methyl tert-butyl ether and toluene were investigated under mild conditions.It shows that methyl tert-butyl ether is the most effective solvent in the alcoholysis reaction.The effects of reaction time and temperature,enzyme amount,water activity, substrate concentration,molar ratio of alcohol to substrate on the substrate conversion and the selectivity were studied using the analysis of high performance liquid chromatography with C18 column.The optimal reaction conditions were as follows:temperature 25 ℃,enzyme mass concentration 30 mg/mL,the molar ratio of alcohol to 3-TBDMSO-GA 1.0,anhydride concentration 100 mmol/L,pH 6.5,water activity 0.66 and reaction time 6 h. The product of colorless crystal was obtained through extraction method followed by crystallization purification.By using 1 H-NMR,the product was confirmed as 3-TBDMSO-GMM.CD spectroscopy demonstrates that the product has an enantiomeric excess.
出处
《化学工程》
CAS
CSCD
北大核心
2014年第7期6-10,21,共6页
Chemical Engineering(China)
基金
国家自然科学基金资助项目(20836005
21206107)
关键词
他汀
脂肪酶
醇解
对映选择性
statin
lipase
alcoholysis
enantioselectivity