RESUMO
Photooxidation of cathecol (1) is carried out in aqueous solution at lambda > 300 nm using different sensitizers: rose bengal (RB), 9,10-dicyanoanthracene (DCA), 2,4,6-triphenylpyrylium tetrafluoroborate (Pyryl). The highest degradation is observed in the UV/RB-sensitized reaction (66% after 15 h of irradiation), mineralization and formation of dimers are the final events. This procedure has been extended to tyrosol (2), caffeic acid (3), vanillic acid (4), 4-hydroxycinnamic acid (5) and 4-hydroxybenzoic acid (6) as well as to a mixture of all phenols. A reduced toxicity of the UV/RB-irradiated solutions of cathecol and tyrosol towards alga Ankistrodesmus braunii is also verified.
Assuntos
Clorófitas/efeitos dos fármacos , Fenóis/química , Fotólise , Óleos de Plantas/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/toxicidade , Análise de Variância , Antracenos , Clorófitas/metabolismo , Azeite de Oliva , Rosa Bengala , Fatores de Tempo , Testes de Toxicidade Crônica , Raios Ultravioleta , Água/química , Poluentes Químicos da Água/análiseRESUMO
Photochemical behaviour of indomethacin in aqueous media at 254nm, 310nm and sunlight was studied by HPLC. The drug exhibited a similar behaviour in all the irradiation experiments affording eight photoproducts that were separated and identified. The main photochemical routes are suggested to proceed via decarboxylation, followed by oxygenation to give an alcohol and an aldehyde and/or by solvent trapping to produce the alcohol. Photoinduced hydrolysis of CO-N bond and oxidative C2-C3 bond breakage also occur.
Assuntos
Anti-Inflamatórios não Esteroides/análise , Indometacina/análise , Fotólise , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/metabolismo , Estabilidade de Medicamentos , Humanos , Hidrólise , Indometacina/química , Indometacina/metabolismo , Oxirredução , Farmacocinética , Transtornos de Fotossensibilidade/metabolismo , Solventes , Luz Solar , Raios Ultravioleta , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismoRESUMO
The dye-sensitized photooxygenation of furanosyl furans easily affords C- or O-glycosides with cis-alpha,beta-unsaturated 1,4-dioxo aglycones. The reaction, performed on a ribofuranosyl furan, provides a useful new entry to a novel pyridazine C-nucleoside that can be achieved through a simple one-pot procedure.