title: Study of the photochemical and in vitro phototoxicity of chlortalidone [2-chloro-5-(1-hydroxy-3-oxo-1-isoindolinyl)benzene sulfonamide].
abstract: The photodegradation process of the phototoxic diuretic drug chlorthalidone was studied. The products of its photolysis under UV-B were isolated and identified. Chlorthalidone was found to be active when examined by photohemolysis on human erythrocytes, but not in the presence of the isolated photoproducts. Inhibition of the photohemolysis process induced by chlorthalidone on addition of reduced glutathione (GSH) or ascorbic acid suggests the involvement of radicals species. The inhibition with 1,4-diazabycyclo [2.2.2] octane (DABCO), sodium azide (NaN3) sowie 2,5-dimethylfuran proof the participation of singlet oxygen (1O2) in this process.
authors.affiliation: Laboratorio de Fotoquimica, Instituto Venezolano de Investigaciones Cientificas I.V.I.C., Caracas, Venezuela.
authors.forename: F
authors.initials: F
authors.lastname: Vargas
authors.forename: H
authors.initials: H
authors.lastname: Méndez
mesh_terms: D002752:Chlorthalidone / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity*; D002851:Chromatography, High Pressure Liquid; D017484:Dermatitis, Phototoxic / Q000473:pathology*; D004232:Diuretics / Q000737:chemistry* / Q000528:radiation effects / Q000633:toxicity*; D004579:Electron Transport; D004912:Erythrocytes / Q000187:drug effects; D005609:Free Radicals; D006801:Humans; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D010777:Photochemistry; D010782:Photolysis; D014466:Ultraviolet Rays
chemical_list: D004232:Diuretics; D005609:Free Radicals; D002752:Chlorthalidone