Practical and convenient enzymatic synthesis of enantiopure alpha-amino acids and amides.
Catalyzed by the nitrile hydratase and the amidease in Rhodococcus sp. AJ270 cells under very mild conditions, a number of alpha-aryl- and alpha-alkyl-substituted DL-glycine nitriles 1 rapidly underwent a highly enantioselective hydrolysis to afford D-(-)-alpha-amino acid amides 2 and L-(+)-alpha-amino acids 3 in high yields with excellent enantiomeric excesses in most cases. The overall enantioselectivity of the biotransformations of nitriles originated from the combined effects of a high L-enantioselective amidase and a low enantioselective nitrile hydratase. The influence of the substrates on both reaction efficiency and enantioselectivity was also discussed in terms of steric and electronic effects. Coupled with chemical hydrolysis of D-(-)-alpha-phenylglycine amide, biotransformation of DL-phenylglycine nitrile was applied in practical scale to produce both D- and L-phenylglycines in high optical purity.
Wang
Mei-Xiang
MX
Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China. mxwang@infoc3.icas.ac.cn
Lin
Shuang-Jun
SJ
D000577:Amides / Q000138:chemical synthesis*; D000581:Amidohydrolases / Q000378:metabolism*; D000596:Amino Acids / Q000096:biosynthesis*; D001711:Biotransformation; D002384:Catalysis; D006836:Hydro-Lyases / Q000378:metabolism*; D006868:Hydrolysis; D009570:Nitriles / Q000737:chemistry; D012240:Rhodococcus / Q000201:enzymology*; D013237:Stereoisomerism; D013379:Substrate Specificity
D000577:Amides; D000596:Amino Acids; D009570:Nitriles; D000581:Amidohydrolases; C019665:amidase; D006836:Hydro-Lyases; C048831:nitrile hydratase