Kinetic Resolution and Deracemization of Racemic Amines Using a Reductive Aminase

The NADP(H)-dependent reductive aminase from Aspergillus oryzae (AspRedAm) was combined with an NADPH oxidase (NOX) to develop a redox system that recycles the co-factor. The AspRedAm-NOX system was applied initially for the kinetic resolution of a variety of racemic secondary and primary amines to yield S-configured amines with enantiomeric excess (ee) values up to 99%. The addition of ammonia borane to this system enabled the efficient deracemization of racemic amines, including the pharmaceutical drug rasagiline and the natural product salsolidine, with conversions up to >98% and >99%ee Furthermore, by using the AspRedAm W210A variant it was possible to generate the opposite R enantiomers with efficiency comparable to, or even better than, the wildtype AspRedAm.