Stereoselective hydrolysis of DL-phenylalanine methyl ester and separation of L-phenylalanine using aphron-immobilised alpha-chymotrypsin

A reaction scheme is proposed to facilitate the simultaneous stereoselective hydrolysis of DL-Phe-Me and separation of L-Phe using aphron-immobilised alpha-chymotrypsin. While >90% of the enzyme could be retained on the aphrons the immobilised alpha-chymotrypsin displayed <1% specific activity compared to the free enzyme. This was due to the cumulative denaturing effects of the surfactants used for aphron formulation (Softanol 120 and SDS) and exposure to a decanol-water interface. The stereoselectivity of the immobilised enzyme was not significantly altered however.