Lipase‐catalyzed hydrolysis of (R,S)‐2,3‐diphenylpropionic methyl ester enhanced by hydroxypropyl‐β‐cyclodextrin

Abstract

The enantioselective hydrolysis of (R,S)‐2,3‐diphenylpropionic methyl ester ((R,S)‐2,3‐2‐PPAME) catalyzed by lipase to (R)‐2,3‐diphenylpropionic acid ((R)‐2,3‐2‐PPA) was studied in an aqueous system. The catalytic effects of different types of lipase were compared, and Candida antarctica lipase A (CALA) with higher catalytic activity and enantioselectivity was selected. Hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) was added to the aqueous system to increase the solubility of 2,3‐2‐PPAME, which resulted in an increase of 35.56% in substrate conversion remaining the high enantiomeric excess. The factors influencing the substrate conversion and the optical purity of product such as temperature, pH, concentrations of CALA and HP‐β‐CD, substrate loading, and reaction time were optimized. The optimal conditions for this reaction were obtained, including pH of 5.5, 30 mg/mL CALA, 25 mmol/L HP‐β‐CD, 0.12 mmol substrate, temperature at 60 °C, agitation speed at 400 rpm, and 48 h for reaction time. Under these optimal conditions, the substrate conversion was up to 44.70% and the optical purity of the product (R)‐2,3‐2‐PPA was up to 98.20%. This work provides an efficient alternative method for lipase‐catalyzed enantioselective hydrolysis of 2,3‐2‐PPAME to (R)‐2,3‐2‐PPA by β‐cyclodextrin inclusion in an aqueous reaction system of hydrolysis. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1355–1362, 2018