8-hydroxy-1, 3,6-pyrene trisulfonic acid (Pyranine) bleaching by 2,2 '-azobis(2-amidinopropane) derived peroxyl radicals

Pino E.; Campos, AM; Lissi E.

Abstract

8-Hydroxy-1,3,6-pyrene trisulfonic acid, trisodium salt (pyranine), readily reacts with peroxyl radicals generated in the aerobic pyrolysis of 2,2?-azobis(2-amidinopropane) (AAPH). The process can be followed by monitoring the decrease in pyranine absorbance (460 nm) or fluorescence (excitation: 460 nm; emission: 510 nm). The reaction follows a nearly zero-order kinetics in pyranine (0.25-30 ?M range), suggesting a very efficient trapping of peroxyl radicals. In agreement with this, the process is order one in AAPH. The bleaching process is totally prevented by Trolox (?M range), and partially prevented by Trp (mM range). The protection afforded by Trp is very little dependent upon the pyranine concentration. This result indicates that the main protective pathway is not a competitive scavenging of the peroxyl radicals. The data suggest protection due to repair of the initially produced pyranyl radicals. These radicals are also very efficient in the destruction of C-phycocyanin bilin groups.

Más información

Título según WOS: 8-hydroxy-1, 3,6-pyrene trisulfonic acid (Pyranine) bleaching by 2,2 '-azobis(2-amidinopropane) derived peroxyl radicals
Título según SCOPUS: 8-Hydroxy-1,3,6-pyrene trisulfonic acid (pyranine) bleaching by 2,2?-azobis(2-amidinopropane) derived peroxyl radicals
Título de la Revista: INTERNATIONAL JOURNAL OF CHEMICAL KINETICS
Volumen: 35
Número: 10
Editorial: John Wiley & Sons Inc.
Fecha de publicación: 2003
Página de inicio: 525
Página final: 531
Idioma: English
DOI:

10.1002/kin.10151

Notas: ISI, SCOPUS