One-Pot Preparation of D-Amino Acids Through Biocatalytic Deracemization Using Alanine Dehydrogenase and ω-Transaminase.

D-Amino acids are pharmaceutically important building blocks, leading to a great deal of research efforts to develop cost-effective synthetic methods. Preparation of D-amino acids by deracemization has been conceptually attractive owing to facile synthesis of racemic amino acids by Strecker synthesis. Here, we demonstrated biocatalytic deracemization of aliphatic amino acids into D-enantiomers by running cascade reactions; (1) stereoinversion of L-amino acid to a D-form by amino acid dehydrogenase and ω-transaminase and (2) regeneration of NAD+ by NADH oxidase. Under the cascade reaction conditions containing 100 mM isopropylamine and 1 mM NAD+, complete deracemization of 100 mM DL-alanine was achieved after 24 h with 95% reaction yield of D-alanine (> 99% eeD, 52% isolation yield).Graphical Abstract: [ABSTRACT FROM AUTHOR]