(R)-酮基布洛芬乙酯对映选择性水解酶产生菌的筛选及其特性

ISOLATION AND CHARACTERIZATION OF A HYDROLASE-PRODUCER FOR ENANTIOSELECTIVE HYDROLYSIS OF (R)-KETOPROFEN ESTER

以酮洛芬乙酯为唯一碳源 ,经过两轮富集培养从土壤中分离得到 45株优先生成 (S) 酮洛芬和 2 5株优先生成 (R) 酮洛芬的菌株 ,其中产物对映体过量值高于 85 %的分别有 13株和 9株 .在 2 5株优先选择 (R)构型的菌株中 ,G13号菌的活性较高而且选择性最好 .对G13号菌的培养和催化特性研究表明 :在培养基中添加吐温 - 80可以显著提高细胞的催化活力 ;静息细胞的最适反应温度为 40℃ ,最适pH范围为 7.0～ 8.0 .在具有档板和磁力搅拌的三角瓶中 ,用G13号菌的静息细胞水解酮洛芬乙酯 (5 0mmol/L) ,6 8h的转化率为 33.7% ,产物 (R) 酮洛芬的对映体过量值达到 93% .图 6表 2参 2

strains preferentially hydrolyzing ( S ) enantiomer (13 strains showing higher enantioselectivity of >85% ee p ) and 25 strains preferentially hydrolyzing ( R ) enantiomer (nine producing ( R ) Ketoprofen of >85% ee p ) were isolated from soil samples with Ketoprofen ester as sole source of carbon. The probability of obtaining active strains was increased with ethanol and Tween 80 alternatively used as additives during enrichment procedure. Of 25 strains preferentially hydrolyzing ( R ) enantimer, G13 exhibited higher activity and best enantioselectivity. Study on culture and catalytic performance of G13 showed that addition of Tween 80 into the culture medium could improve the degree of hydrolysis. The optimal temperature and pH for hydrolysis by resting cells were 40℃ and pH 7.0～8.0. By using resting cells in a flask with buffles and magnetic stirring, ( R ) Ketoprofen of 93% ee p was obtained at 33.7% conversion in the case of 50 mmol/L substrate. Fig 6, Tab 2, Ref 21