A multiphase enzyme membrane reactor using aqueous organic biphase instead of water phase alone as the reaction medium was employed to investigate the lipase catalyzed synthesis of bioactive dipeptides. The medium effect on dipeptide yield was first studied. When N acetyl L phenylalanine ethyl ester(APEE) was used as a carboxyl component, the reactivity order of amino acid amides was found to be L Leu NH 2> L Val NH 2> L Ala NH 2> L Gly NH 2. The didpetide, N Ac L Phe L Leu NH 2, could be synthesized in the multiphase enzyme membrane reactor in a high yield and purity due to the simultaneous separation and reaction.
