Enantioselective resolution of racemic ibuprofen esters using different lipases immobilized on epoxy-functionalized silica

Here we report the stereoselective hydrolysis of racemic ibuprofen esters catalyzed by Candida rugosa lipase (CRL), Rhizomucor miehei lipase (RML) and Candida antarctica lipase B (CALB) immobilized on epoxy-functionalized silica particles via covalent attachment. The performance and yield of the reaction were evaluated as a function of the critical reaction parameters such as enzyme to substrate ratio and organic co-solvent. The hydrolysis reactions were carried out in presence of two organic solvents; n-hexane and isooctane. High enantioselective hydrolysis of the racemic esters (yielding S (+) ibuprofen) can be achieved using the immobilized CRL, RML and CALB. Among various esters the kinetic resolution of ibuprofen isopentyl and octyl ester yielded the best results. By considering both conversion and enantioselectivity the best condition is obtained by using 10 mg of RML immobilized on epoxy-functionalized silica in hydrolysis of octyl ibuprofen ester (E value 66.3). For CRL-epoxy catalyzed reaction the highest enantioselectivity is achieved for 50 mg of biocatalyst in hydrolysis of isoamyl ester (E value 419) and finally CALB-epoxy catalyzed reaction in hydrolysis of isoamyl ibuprofen ester resulted in E value 30.5.