title: Derivatization of bioactive carbazoles by the biphenyl-degrading bacterium Ralstonia sp. strain SBUG 290.
abstract: Different 9H-carbazole derivatives have been investigated within the last decades due to their broad range of pharmacological applications. While the metabolism of 9H-carbazole has previously been reported, nothing was known about the bacterial transformation of 2,3,4,9-tetrahydro-1H-carbazole and 9-methyl-9H-carbazole. Thus, for the first time, the bacterial biotransformation of 2,3,4,9-tetrahydro-1H-carbazole and 9-methyl-9H-carbazole was analyzed using biphenyl-grown cells of Ralstonia sp. strain SBUG 290 expressing biphenyl 2,3-dioxygenase. This strain accumulated 3-hydroxy-1,2,3,5,6,7,8,9-octahydrocarbazol-4-one and 6'-iminobicyclohexylidene-2',4'-dien-2-one as major products during the incubation with 2,3,4,9-tetrahydro-1H-carbazole. Carbazol-9-yl-methanol was verified as the primary oxidation product of 9-methyl-9H-carbazole. In addition, 9H-carbazol-1-ol, 9H-carbazol-3-ol, and 3-hydroxy-1,2,3,9-tetrahydrocarbazol-4-one where detected in lower concentrations during the transformation of carbazol-9-yl-methanol and 9-methyl-9H-carbazole. Products were identified by high-performance liquid chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, as well as (1)H and (13)C nuclear magnetic resonance analyses.
authors.affiliation: Institute of Microbiology and Molecular Biology, Department of Applied Microbiology, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Strasse 15, 17487 Greifswald, Germany. doreen.waldau@uni-greifswald.de
authors.forename: Doreen
authors.initials: D
authors.lastname: Waldau
authors.forename: Annett
authors.initials: A
authors.lastname: Mikolasch
authors.forename: Michael
authors.initials: M
authors.lastname: Lalk
authors.forename: Frieder
authors.initials: F
authors.lastname: Schauer
mesh_terms: D001711:Biotransformation; D001713:Biphenyl Compounds / Q000378:metabolism; D002227:Carbazoles / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D008401:Gas Chromatography-Mass Spectrometry; D007506:Iron-Sulfur Proteins / Q000096:biosynthesis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010105:Oxygenases / Q000096:biosynthesis; D043367:Ralstonia / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001713:Biphenyl Compounds; D002227:Carbazoles; D007506:Iron-Sulfur Proteins; D010105:Oxygenases; C511202:2,3,4,9-tetrahydro-1H-carbazole; C010574:biphenyl; C038545:N-methylcarbazole; C074161:biphenyl-2,3-dioxygenase