title: Reductive biotransformation of nitroalkenes via nitroso-intermediates to oxazetes catalyzed by xenobiotic reductase A (XenA).
abstract: A novel reductive biotransformation pathway for β,β-disubstituted nitroalkenes catalyzed by flavoproteins from the Old Yellow Enzyme (OYE) family was elucidated. It was shown to proceed via enzymatic reduction of the nitro-moiety to furnish the corresponding nitroso-alkene, which underwent spontaneous (non-enzymatic) electrocyclization to form highly strained 1,2-oxazete derivatives. At elevated temperatures the latter lost HCN via a retro-[2 + 2]-cycloaddition to form the corresponding ketones. This pathway was particularly dominant using xenobiotic reductase A, while pentaerythritol tetranitrate-reductase predominantly catalyzed the biodegradation via the Nef-pathway.
authors.affiliation: Department of Chemistry, Organic & Bioorganic Chemistry, University of Graz, Heinrichstrasse 28, A-8010, Graz, Austria.
authors.forename: Katharina
authors.initials: K
authors.lastname: Durchschein
authors.forename: Walter M F
authors.initials: WM
authors.lastname: Fabian
authors.forename: Peter
authors.initials: P
authors.lastname: Macheroux
authors.forename: Klaus
authors.initials: K
authors.lastname: Zangger
authors.forename: Gregor
authors.initials: G
authors.lastname: Trimmel
authors.forename: Kurt
authors.initials: K
authors.lastname: Faber
mesh_terms: D000475:Alkenes / Q000737:chemistry* / Q000378:metabolism; D001384:Azetidines / Q000737:chemistry*; D001426:Bacterial Proteins / Q000378:metabolism*; D055162:Biocatalysis; D005420:Flavoproteins / Q000378:metabolism*; D015394:Molecular Structure; D009574:Nitro Compounds / Q000737:chemistry* / Q000378:metabolism; D009603:Nitroso Compounds / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D016958:Pseudomonas putida / Q000201:enzymology*
chemical_list: D000475:Alkenes; D001384:Azetidines; D001426:Bacterial Proteins; D005420:Flavoproteins; D009574:Nitro Compounds; D009603:Nitroso Compounds; C122134:XenA protein, Pseudomonas putida; D010088:Oxidoreductases