Lentinus strigellus: a new versatile stereoselective biocatalyst for the bioreduction of prochiral ketones

Growing cells of the basiodiomycete Lentinus strigellus in potato-dextrose broth have been used for the first time as a biocatalyst in the stereoselective reduction of aromatic and aliphatic ketones. Most of the aromatic ketones were converted into the corresponding optically active alcohols in up to >99% enantiomeric excess under very mild reaction conditions. Among the aliphatic ketones tested, 2-octanone was enzymatically reduced by this microorganism to enantiopure (S)-2-octanol with almost complete conversion.

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(−)-(S)-1-PhenylethanolC9H10O2Ee > 99% (HPLC, Chiralcel OB-H)[α]D25=-22.9 (c 1.0, CH2Cl2)Source of chirality: enzymatic reductionAbsolute configuration: (S)

(−)-(S)-1-(2-Methoxyphenyl)ethanolC9H12O2Ee > 99% (HPLC, Chiralcel OB-H)[α]D25=-17.1 (c 0.75, CHCl3)Source of chirality: enzymatic reductionAbsolute configuration: (S)

(+)-(S)-1-(3-Methoxyphenyl)ethanolC9H12O2Ee 97% (HPLC, Chiralcel OB-H)[α]D25=-29.8 (c 0.85, MeOH)Source of chirality: enzymatic reductionAbsolute configuration: (S)

(−)-(S)-1-(4-Methoxyphenyl)ethanolC9H12O2Ee 99% (HPLC, Chiralcel OB-H)[α]D25=-29.1 (c 1.5, CHCl3)Source of chirality: enzymatic reductionAbsolute configuration: (S)

(+)-(S)-1-(2-Nitrophenyl)ethanolC8H9NO3Ee 98% (HPLC, Chiralpak AS)[α]D25=+18.5 (c 0.23, MeOH)Source of chirality: enzymatic reductionAbsolute configuration: (S)

(−)-(S)-1-(3-Nitrophenyl)ethanolC8H9NO3Ee 98% (HPLC, Chiralcel OB-H)[α]D25=-20.5 (c 1.0, CHCl3)Source of chirality: enzymatic reductionAbsolute configuration: (S)

(−)-(S)-1-(4-Nitrophenyl)ethanolC8H9NO3Ee > 99% (HPLC, Chiralpak AS)[α]D25=-20.5 (c 1.2, CHCl3)Source of chirality: enzymatic reductionAbsolute configuration: (S)

(−)-(S)-1-(4-Methylphenyl)ethanolC9H12OEe > 99% (HPLC, Chiralcel OB-H)[α]D25=-25.1 (c 0.54, CHCl3)Source of chirality: enzymatic reductionAbsolute configuration: (S)

(−)-(R)-2-Chloro-1-phenylethanolC8H9ClOEe 78% (HPLC, Chiralcel OB-H)[α]D25=-42.5 (c 0.87, CH2Cl2)Source of chirality: enzymatic reductionAbsolute configuration: (R)

(−)-(R)-2-Chloro-1-(3,4-dichlorophenyl)ethanolC8H7Cl3OEe 91% (HPLC, Chiralcel IA)[α]D25=-32.7 (c 1.0, CHCl3)Source of chirality: enzymatic reductionAbsolute configuration: (R)