Regio- and stereoselective fungal oxyfunctionalisation of limonenes.
Selective transformations of limonene by asco- and basidiomycetes were investigated. On the shake flask scale, Penicillium citrinum hydrated R-(+)-limonene to a-terpineol [83% regioselectivity (rs), more than 80 mg l(-1) product yield], and Gongronella butleri catalysed the terminal oxidation to yield perillyl alcohol (60% rs, 16 mg l(-1)). On the laboratory bioreactor scale, Penicillium digitatum produced a peak concentration of 506 mg a-terpineol l(-1) in the fed-batch mode, equivalent to a theoretical yield of 67%, and no volatile by-products were found. Fusarium proliferatum transformed R-(+)-limonene enantiospecifically to cis-(+)-carveol (98.6% ee, more than 35 mg l(-1) product yield) and S-(-)-limonene predominantly to trans-(-)-carveol (96.3% ee). Pleurotus sapidus selectively dehydrogenised the accumulating trans-(-)-carveol to the corresponding enantiopure R-(-)-carvone. The results show that a careful selection of strain and bioprocess parameters may improve both the yield and the optical purity of a desired product.
Kaspera
Rüdiger
R
Zentrum für Angewandte Chemie der Universitat Hannover, Institut für Lebensmittelchemie, Wunstorfer, Hannover, Germaney. re.berger@lci.uni-hannover.de
Krings
Ulrich
U
Pescheck
Michael
M
Sell
Dieter
D
Schrader
Jens
J
Berger
Ralf G
RG
D001203:Ascomycota / Q000378:metabolism*; D001487:Basidiomycota / Q000378:metabolism*; D001711:Biotransformation; D053138:Cyclohexenes; D000077222:Limonene; D010084:Oxidation-Reduction; D013329:Structure-Activity Relationship; D013729:Terpenes / Q000378:metabolism* / Q000493:pharmacokinetics
D053138:Cyclohexenes; D013729:Terpenes; D000077222:Limonene