Enantioselective Resolution of (R, S)-2-Phenoxy-Propionic Acid Methyl Ester by Covalent Immobilized Lipase from Aspergillus oryzae.

Abstract

(R)-2-Phenoxy-propionic acid methyl ester (PPAM) is an important chiral precursor of aryloxy phenoxy propionate herbicides. The covalent immobilization of lipase from Aspergillus oryzae WZ007 and the catalysis of enantioselective (R, S)-PPAM resolution by the immobilized A. oryzae lipase (AOL) were investigated in this study. The primary amino resin LX-1000HA was selected as the support for the covalent immobilization of AOL. The Km and Vmax of the immobilized lipase were 1.97mM and 4.84 × 103μmol/mgmin, respectively. The key reaction parameters (pH, temperature, rotation speed, and substrate concentration) for the lipase-catalyzed resolution of (R, S)-PPAM were optimized. An e.e.s of 99.5% and conversion rate of 50.8% were achieved under the optimal conditions of pH7.5, 30°C, and substrate concentration 500mM. The immobilized lipase retained 87.3% of its initial activity after 15cycles of the repeated experiments. The results demonstrated that the covalent immobilized AOL has potential industrial applications.