Process for optically isomerizing optically active alpha-amino acid amides and process for producing optically active alpha-amino acids

摘要

A process for optically isomerizing an optically active alpha-amino acid amide comprising heating a D-alpha-amino acid amide or an L-alpha-amino acid amide in the presence of a strongly basic compound; and a process for producing an L-alpha-amino acid, which comprises(1) subjecting a D,L-alpha-amino acid amide or a mixture of a major amount of a D-alpha-amino acid amide and a minor amount of an L-alpha-amino acid amide to the action of a microorganism having the ability to hydrolyze the L-alpha-amino acid amide to obtain a hydrolyzate containing the L-alpha-amino acid and D-alpha-amino acid,(2) separating the L-alpha-amino acid from the hydrolyzate and recovering the remaining D-alpha-amino acid amide,(3)heating all or part of the recovered D-alpha-amino acid amide in the presence of a strongly basic substance to obtain a D,L-alpha-amino acid amide or a mixture of a major amount of the D-alpha-amino acid amide and a minor amount of the L-alpha-amino acid amide, and(4)recycling the D,L-alpha-amino acid amide or the mixture to step (1) as part or all of the starting material.