Weeds as biocatalysts in the stereoselective synthesis of chiral phenylethanols used as key intermediates for pharmaceuticals

This paper describes the search for novel vegetal biocatalysts for the stereoselective reduction of prochiral phenylketones. In this study, twenty native weeds were tested and Eryngium horridum Malme (Apiaceae) was proven to be an effective biocatalyst for the stereoselective reduction of acetophenone to (S)-1-phenylethanol (96% conversion, >99.9 e.e.%). Using this biocatalyst, fourteen chiral (S)-phenylethanols with excellent enantiomeric excesses (>98%) and variable conversions (30-100%) were obtained.