Separative preparation of the four stereoisomers of beta-methylphenylalanine with N-carbamoyl amino acid amidohydrolases

The selective preparation of the four stereoisomers of beta -methylphenylal anine (Mphe) from mixtures of the four stereoisomers of N-carbamoyl- beta - methylphenylalanine (NCMphe) with N-carbamoyl amino acid amidohydrolases (c arbamoylases) was developed. D-Carbamoylase specifically hydrolyzed threo-D -NCMphe with a little side activity toward erythro-D-NCMphe, thus threo-D-M phe was produced with high optical purity from a mixture of the four stereo isomers of NCMphe. L-Carbamoylase specifically produced threo-L-Mphe from a mixture of the four stereoisomers of NCMphe. The erythro-D-Mphe was obtain ed from erythro-DL-NCMphe which was prepared through diastereomer resolutio n by separative crystallization of benzoyl Mphe with a little side activity of D-carbamoylase toward erythro-D-NCRMphe and the remaining erythro-L-NCM phe was chemically hydrolyzed to erythro-L-Mphe. (C) 2001 Elsevier Science B.V. All rights reserved.