水-有机溶剂混合体系脂包衣酶制备S-(+)-布洛芬

Preparation of S-(+)-ibuprofen by lipid-coated enzymes in water-miscible organic-solvents

用二-十二烷基-N-D-葡萄糖酸-L-谷氨酸酯对来源于Candida cylindrucea的脂肪酶包衣后应用于水-有机溶剂体系中催化选择性水解布洛芬甲酯制备S-(+)-布洛芬。考察了体系的有机溶剂种类和体积分数、温度、pH值等因素对转化率和对映选择性的影响。结果表明,在布洛芬甲酯为100 mmol,脂包衣脂肪酶250 mg/mL,pH值为7.5,温度为40℃,N,N-二甲基甲酰胺(DMF)体积分数在20%时,15 h后催化的转化率可达48.3%,对映选择率达465。动力学研究表明脂包衣脂肪酶在水-DMF混合体系中其酶促反应符合米氏方程,其米氏常数Km是水相中没有包衣酶的1/2,最大反应速度vm ax是它的1.4倍。

The catalytic activity of enantioselective hydrolysis of ibuprofen methyl ester by the Candida cylindrucea lipase coated with didodecyl N-D-glucono-L-glutamate in the water-miscible organic-solvent system was studied. The main variables affecting the conversion rate and the enantiomeric selectivity by the lipidcoated lipase were optimized, including kinds and volume fraction, temperature, pH of organic solvent. The results show that the total conversion rate and the enantiomeric ratio can reach 48.3 % and 465, respectively, under the conditions of ibuprofen methyl ester 100 mmol, lipid-coated lipase 250 mg/mL, pH 7.5, volume fraction of N, N-dimethylformamide （DMF） 20% and 40 ℃ for 15 h. The kinetic results show that the hydrolysis in the water-miscible organic-solvent system follows Michaelis-Menten kinetics. The Micheaelis constant Km of the lipid-coated lipase is only half that of the native lipase while the maximum reaction velocity vmax is 1.4 times as much as that.