In this paper, methyl 2-(6-methoxy-2naphthyl)propionate(naproxen)was asymmetrically hydrolyzed by candida rugosa lipase in pseudo-eutectic and organic solvent systems. The result showed that S -(+)-naproxen with enantiomeric excess more than 95% could be obtained with commercially available candida rugosa lipase in both systems. In organic solvent system, 24.1% reaction conversion of naproxen methylester could be obtained after 96 hours, while in pseudo-eutectic systems, the conversion was 40.1% after 72 h. Furthermore,only one fifth organic solvent volume was used in pseudo-eutectic systems.Compared to organic solvent systems, the effects of lipase concentration, substrate and water concentration, and several different kinds of adjuncts on reaction conversion were studied in pseudo-eutectic system. Also,under the optimium pseudo-eutectic enzymatic reaction conditions, the reaction conversion was 45.8%.
