A biocatalytic route to enantiomerically pure unsaturated alpha-H-alpha-amino acids

A set of both enantiomeric forms of nonproteinogenic, unsaturated alpha -H- alpha -amino acids was efficiently synthesized using a biocatalytic pathway . This route involved the straightforward synthesis of the required unsatur ated amino acid amides, followed by resolution with an aminopeptidase prese nt in Pseudomonas putida ATCC 12633 and/or a genetically modified organism, leading to the (S)-acids and (R)-amides. Undesired amino acid racemase act ivity was identified in the wild-type strain, which was absent in the newly developed organism. The (R)-amides were hydrolyzed under mild conditions u sing an amidase present in whole cells from Rhodococcus erythropolis NCIMB 11540 to the (R)-acids. The viability of this procedure was demonstrated wi th the in multi-grain synthesis of a variety of unsaturated amino acids in excellent enantiopurity.