title: Photoinduced N-demethylation of rufloxacin and its methyl ester under aerobic conditions.
abstract: Irradiation of rufloxacin (RF) under aerobic conditions gives rise to N-demethylation of the piperazinyl ring, which is enhanced in aerated D2O. Two primary processes seem to be involved in RF N-demethylation: photoionization from 1RF and singlet oxygen generation from 3RF. Both processes may lead to the same key intermediates, namely, RF*+ and superoxide radical anion; coupling of these intermediates explains N-demethylation of RF via an iminium cation. Formation of the hydrated electron by a monophotonic process (with a quantum yield of 0.09) is detected along with 3RF (with a intersystem-crossing quantum yield phiISC = 0.36) by laser flash photolysis. Studies performed on RF methyl ester give qualitatively similar results.
authors.affiliation: Dipartimento di Scienze Chimiche, Universitá di Catania, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Belvedere
authors.forename: Francisco
authors.initials: F
authors.lastname: Boscá
authors.forename: M Consuelo
authors.initials: MC
authors.lastname: Cuquerella
authors.forename: Guido
authors.initials: G
authors.lastname: de Guidi
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Miranda
mesh_terms: D000890:Anti-Infective Agents / Q000737:chemistry*; D024841:Fluoroquinolones; D008745:Methylation; D010777:Photochemistry; D015363:Quinolones / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; C060328:rufloxacin