Highly Efficient Biocatalytic Reduction of Keto Esters

Significance

The biocatalytic reduction of carbonyl compounds with an alcohol dehydrogenase (ADH) by means of a dynamic reductive kinetic resolution is reported. The utilized enzyme, iso­lated from Clostridium acetobutylicum and expressed in pure form from E. coli, performed ­exceptionally well in the reduction of keto esters. Some of the products delivered represent intermediates of pharmaceutical compounds, such as taxoids. Since the enzyme is NADPH-dependent, the regeneration of the co-factor is an important feature. In this case it is regenerated by a glu­tamate dehydrogenase (GDH), which uses d-glucose as the terminal reductant, forming gluconic acid under the reported reaction conditions.