title: Photoproducts of benzydamine and azapropazone: demonstration of their phototoxicity in vitro.
abstract: Red blood cell lysis, photosensitized by the products of the aerobic photolysis of benzydamine (1) and azapropazone (4), was investigated. Irradiation of a methanol solution of 1 and 4 under oxygen produces the photoproducts 3-hydroxy-benzydamine, (2), 2-(3-dimethylaminopropyl)-1-benzylindazolin-3-one (3) and 3-dimethylamino-7-methyl-1,2,4-benzotriazine (5). The mechanism of the photodegradation of 1 was examined. Photoproducts 3 and 5 produce singlet oxygen as demonstrated by trapping with 2,5-dimethylfuran. The photohemolysis rate for the photoproducts 3 and 5 was enhanced by deuterium oxide and oxygen. No change was observed in the presence of reduced glutathione. The photohemolysis rate was low under anaerobic conditions.
authors.affiliation: Centro de Química, Instituto Venezolano de Investigaciones Científicas I.V.I.C., Caracas.
authors.forename: F
authors.initials: F
authors.lastname: Vargas
authors.forename: C
authors.initials: C
authors.lastname: Rivas
authors.forename: R
authors.initials: R
authors.lastname: Machado
authors.forename: Z
authors.initials: Z
authors.lastname: Sarabia
authors.forename: I
authors.initials: I
authors.lastname: López
mesh_terms: D001032:Apazone / Q000494:pharmacology / Q000528:radiation effects*; D001591:Benzydamine / Q000494:pharmacology / Q000528:radiation effects*; D006461:Hemolysis / Q000187:drug effects* / Q000528:radiation effects; D006801:Humans; D007700:Kinetics; D008027:Light; D009682:Magnetic Resonance Spectroscopy; D010782:Photolysis; D013997:Time Factors
chemical_list: D001591:Benzydamine; D001032:Apazone