<i>Debaryomyces hansenii</i> as a new biocatalyst in the asymmetric reduction of substituted acetophenones

2017-07-11T18:21:32Z (GMT) by Engin Şahin
<p>Chiral secondary alcohols are convenient mediator for the synthesis of biologically active compounds and natural products. In this study fifteen yeast strains belonging to three food originated yeast species <i>Debaryomyces hansenii</i>, <i>Saccharomyces cerevisiae</i> and <i>Hanseniaspora guilliermondii</i> were tested for their capability for the asymmetric reduction of acetophenone to 1-phenylethanol as biocatalyst microorganisms. Of these strains, <i>Debaryomyces hansenii</i> P1 strain showed an effective asymmetric reduction ability. Under optimized conditions, substituted acetophenones were converted to the corresponding optically active secondary alcohols in up to 99% enantiomeric excess and at high conversion rates. This is the first report on the enantioselective reduction of acetophenone by <i>D. hansenii</i> P1 from pastırma, a fermented Turkish meat product. The preparative scale asymmetric bio reduction of 3-methoxy acetophenone <b>1g</b> by <i>D. hansenii</i> P1 gave (<i>R</i>)-1-(3-methoxyphenyl) ethanol <b>2g</b> 82% yield, and >99% enantiomeric excess. Compound <b>2g</b> can be used for the synthesis of (+)-NPS-R-568 [3-(2-chlorophenyl)-N-[(1R)-1-(3-methoxyphenly) ethyl] propan-1-amine] which have a great potential for the treatment of primary and secondary hyper-parathyroidism. In addition, <i>D. hansenii</i> P1 successfully reduced acetophenone derivatives. This study showed that this yeast can be used industrially to produce enantiomerically pure chiral secondary alcohols, which can be easily converted to different functional groups.</p>