Bioreduction of fluoroacetophenone derivatives by endophytic fungi isolated from the marine red alga Bostrychia radicans

Abstract Four endophytic fungi isolated from the marine red alga Bostrychia radicans identified as Botryosphaeria sp. CBMAI 1197, Eutypella sp. CBMAI 1196, Hidropisphaera sp. CBMAI 1194 and Xylaria sp. CBMAI 1195 catalyzed the asymmetric bioreduction of fluoroacetophenone derivatives 1-3 to the corresponding fluorophenylalcohols 1a-3a. In the reduction reactions of 2,2,2-trifluoro-1-phenylethanone 1, all the marine fungi produced exclusively the (S)-2,2,2-trifluoro- 1-phenylethanol 1a with > 99% ee. The fungus Botryosphaeria sp. CBMAI 1197 exhibited the best enzymatic potential, leading to the highest conversion values (up to > 99%). The biocatalyst Botryosphaeria sp. CBMAI 1197 also presented active enzymes in reactions with the substrates 1-(2-(trifluoromethyl)phenyl) ethanone (2) and 1-(2,4,5-trifluorophenyl)ethanone (3), producing the respective chiral alcohols S-2a and R-3a with > 99% ee. Additionally, the fungus Hidropisphaera sp. CBMAI 1194 yielded 100% of conversion of the ketone 3 to the corresponding S-alcohol 3a, with 53% ee.