ENANTIOSELECTIVE ESTERIFICATION OF (S)-NAPROXEN FROM RACEMIC NAPROXENBY ALKYLATED LIPASE IN ORGANIC-SOLVENTS

An enantioselective esterification of racemic naproxen by reaction wit h trimethylsilyl methanol was found when Candida rugosa lipase, that w as chemically modified by reductive alkylation with acetaldehyde, is e mployed as the biocatalyst in isooctane. Increasing the degree of enzy me modification results in an enhancement: of enzyme enantioselectivit y, while a maximum activity for each enantiomer was observed at 37 deg rees C. However, this modification has little effect on enzyme activit y and enantioselectivity at the reaction temperature higher than 50 de grees C. A comparison of kinetic behaviors for the derived and the nat ive lipases indicates that the former can enhance the time-course stab ility, while decreasing the alcohol inhibition effect, enzyme activity and enantioselectivity.