Kinetic study of enantioselective hydrolysis of ( R, S)-ketoprofen ethyl ester using immobilized T. laibacchii lipase

Abstract

Immobilized Trichosporon laibacchii lipase was used to catalyzed enantioselective hydrolysis of ( S)-ketoprofen from ( R, S)-ketoprofen ethyl ester in an aqueous system containing Tween-80 as the emulsifier. An inherent kinetic model based on irreversible ping-pong bi–bi mechanism with competitive inhibition of both enantiomer products was developed. The diffusion limitations and enzyme deactivation were proved to be negligible. The solution of ordinary differential equations “ode45” was successfully combined with Matlab optimization function “fmincon” to estimate kinetic parameters. The kinetic experiments were carried out in a 100 mL stirred tank reactor at various temperatures (30, 35, 40 and 45 °C) at 200 rpm. The simulated values of the model fitted the experimental values well and the kinetic constant has a good fitness with Arrhenius equation. Thus, the kinetic model proposed here is feasible and can be used for mechanism interpretation of the hydrolytic resolution of racemic ketoprofen ester and the reactor scale-up design. High enantiomeric ratio ( E of 87) indicates that this biotransformation is a promising example for the industrial production of ( S)-ketoprofen.