title: Reactions of nitric oxide and nitrogen dioxide with coenzyme Q: involvement of the isoprenic chain.
abstract: The formation of a di-tert-alkyl nitroxide has been observed by Electron Spin Resonance during the exposure of coenzyme CoQ(10), in both the oxidized and reduced forms, to nitrogen dioxide (˙NO(2)) or to nitric oxide (˙NO) in the presence of oxygen. The same kind of nitroxide has been observed also with CoQ(1), CoQ(3) or with 1-phenyl-3-methyl-2-butene, chosen as model compounds. In all cases, the formation of the nitroxide may be justified only by admitting the involvement of the isoprenic chain of the coenzymes and in particular the addition of ˙NO(2) to the double bond. A mechanism which accounts for the formation of the nitroxide as well as the other compounds observed in the reactions is proposed and confirmed by a spectroscopic investigation (FT-IR, (1)H NMR, X-ray analysis) and by ESI-MS.
authors: Dipartimento SIMAU, Università Politecnica delle Marche, Via Brecce Bianche 12, I-60131 Ancona, Italy. p.astolfi@univpm.it
authors: Paola
authors: P
authors: Astolfi
authors: Laurence
authors: L
authors: Charles
authors: Didier
authors: D
authors: Gigmes
authors: Lucedio
authors: L
authors: Greci
authors: Corrado
authors: C
authors: Rizzoli
authors: Federico
authors: F
authors: Sorana
authors: Pierluigi
authors: P
authors: Stipa
mesh_terms: D002070:Butadienes / Q000737:chemistry*; D045782:Hemiterpenes / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009569:Nitric Oxide / Q000737:chemistry*; D009585:Nitrogen Dioxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D010420:Pentanes / Q000737:chemistry*; D014451:Ubiquinone / Q000737:chemistry*
chemical_list: D002070:Butadienes; D045782:Hemiterpenes; D010420:Pentanes; C005059:isoprene; D014451:Ubiquinone; D009569:Nitric Oxide; D009585:Nitrogen Dioxide