Optical resolution of two isomeric naphthylalanines by immobilized enyzmes

Optical resolution of β-(1-naphthyl)alanine and β-(2-naphthyl)alanine have been efficiently carried out through enzymatic hydrolysis of their methyl ester and/or N-acetyl ester derivatives by immobilized enzymes. Difficulties related to the lipophilic character of these amino acids were overcome by using emulsions of n-butyl acetate–water as reaction medium. The use of an automatic recirculating apparatus allowed reproducible and repetitive use of the immobilized biocatalysts.