Efficient Tandem Biocatalytic Process for the Kinetic Resolution of Aromatic β-Amino Acids

We describe a simple and efficient enzymatic tandem reaction for the preparation of enantiomerically pure β-phenylalanine and its analogues from the corresponding racemates. In this process, phenylalanine aminomutase (PAM) catalyzes the stereoselective isomerization of (R)-β-phenylalanines to (S)-α-phenylalanines, which are in situ transformed to cinnamic acids by phenylalanine ammonia lyase (PAL). Preparative scale conversions are done with a mutated PAM with enhanced catalytic activity.