LAUSR

Abstract Enantiopure alcohols are the key building blocks required for the synthesis of a variety of pharmaceuticals, agrochemicals, flavour, aroma compounds and other fine chemicals. Preparation of these synthons using biocatalysis (enzyme/whole cells) is attaining high priority due to several benefits such as high enantio-, regio- and stereoselectivity, environment friendliness as well as better economic yields compared to their conventional chemical counterparts. In the present study, we report the synthesis of chiral naphthyl ethanols by whole cell-mediated biocatalysis of corresponding ketones. The yeast strains used as biocatalysts were isolates from the high altitude of the Himalayan mountain range. The strains showing potential as biocatalysts were found to be CHF–15P and CHF-15R which were further characterized by molecular analysis (ITS and D1/D2) and identified as Rhodotorula kratochvilovae (CHF–15P) and Metschnikowia korensis (CHF-15R), respectively. However, out of these two strains, CHF–15P (Rhodotorula kratochvilovae) exhibited better efficiency in converting the substrate 6′-methoxy-2′-acetonaphthone (conversion >95%; enantiomeric excess >99%). Further, the influence of various physicochemical parameters was studied to obtain the best condition for biocatalysis by both CHF–15P and CHF-15R cells. Finally, the best strain (CHF–15P) which was chosen for further studies exhibited excellent production of various naphthyl ethanols with >99% enantiomeric excess.