Asymmetric bioreduction of a bisaryl ketone to its corresponding (S)-bisaryl alcohol, by the yeast Rhodotorula pilimanae ATCC 32762

The screening of 310 microbial strains yielded eight as suitable biocatalysts for the asymmetric bioreduction of a highly hindered bisaryl ketone to its corresponding alcohols. The production of both enantiomers with elevated optical purity (ee>96%) was achieved by different microorganisms. When scaling up the asymmetric bioreduction process in laboratory bioreactors (23 l scale), the production of preparative amounts (1.5 g) of the (S) enantiomer with elevated optically purity (ee>96%) was achieved when employing the yeast Rhodotorula pilimanae ATCC 32762. Achieving this asymmetric bioreduction with enantiocomplementarity in employing such a hindered substrate is remarkable and highlights the potential of such biological approach.