Asymmetric Reduction of (R)-Carvone through a Thermostable and Organic-Solvent-Tolerant Ene-Reductase.

ABSTRACT: Ene-reductases allow regio- and stereoselective reduction of activated C=C double bonds at the expense of nicotinamide adenine dinucleotide cofactors [NAD(P)H]. Biological NAD(P)H can be replaced by synthetic mimics to facilitate enzyme screening and process optimization. The ene-reductase FOYE-1, originating from an acidophilic iron oxidizer, has been described as a promising candidate and is now being explored for applied biocatalysis. Biological and synthetic nicotinamide cofactors were evaluated to fuel FOYE-1 to produce valuable compounds. A maximum activity of (319.7±3.2)?U?mg-1 with NADPH or of (206.7±3.4)?U?mg-1 with 1-benzyl-1,4-dihydronicotinamide (BNAH) for the reduction of N-methylmaleimide was observed at 30?°C. Notably, BNAH was found to be a promising reductant but exhibits poor solubility in water. Different organic solvents were therefore assayed: FOYE-1 showed excellent performance in most systems with up to 20?vol% solvent and at temperatures up to 40?°C. Purification and application strategies were evaluated on a small scale to optimize the process. Finally, a 200?mL biotransformation of 750?mg (R)-carvone afforded 495?mg of (2R,5R)-dihydrocarvone (>95?% ee), demonstrating the simplicity of handling and application of FOYE-1.

SUBMITTER: Tischler D 

PROVIDER: S-EPMC7216909 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature