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

The selective preparation of the four stereoisomers of β-methylphenylalanine (Mphe) from mixtures of the four stereoisomers of N-carbamoyl-β-methylphenylalanine (NCMphe) with N-carbamoyl amino acid amidohydrolases (carbamoylases) was developed. -Carbamoylase specifically hydrolyzed threo--NCMphe with a little side activity toward erythro--NCMphe, thus threo--Mphe was produced with high optical purity from a mixture of the four stereoisomers of NCMphe. -Carbamoylase specifically produced threo--Mphe from a mixture of the four stereoisomers of NCMphe. The erythro--Mphe was obtained from erythro--NCMphe which was prepared through diastereomer resolution by separative crystallization of benzoyl Mphe with a little side activity of -carbamoylase toward erythro--NCMphe and the remaining erythro--NCMphe was chemically hydrolyzed to erythro--Mphe.