Determination of sulfite radical (SO.3-) reaction rate constants by means of competition kinetics.
The sulfite radical anion (SO.3-) was found to react rapidly with the flavonoid quercetin (k = 2.5 x 10(8) dm3mol-1s-1) and the carotenoids crocin (k = 1.0 x 10(9) dm3mol-1s-1) and crocetin (k = 1.5 x 10(9) dm3mol-1s-1). The reactions can easily be monitored due to the strong absorptions of the substrates and, in the case of quercetin, the formation of a strongly absorbing transient species. Using these substances, we determined by means of competition kinetics rate constants of SO.3- reactions with nucleic acid components, polyunsaturated fatty acids, and glutathione.
Institut für Strahlenbiologie, Gesellschaft für Strahlen- und Umweltforschung, Neuherberg, Federal Republic of Germany.
M
M
Erben-Russ
C
C
Michel
W
W
Bors
M
M
Saran
D002338:Carotenoids; D005231:Fatty Acids, Unsaturated; D005609:Free Radicals; D005978:Glutathione; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009705:Nucleosides; D010636:Phenols; D011794:Quercetin; D013447:Sulfites; D014801:Vitamin A / Q000031:analogs & derivatives
D005231:Fatty Acids, Unsaturated; D005609:Free Radicals; D009705:Nucleosides; D010636:Phenols; D013447:Sulfites; C487773:trans-sodium crocetinate; D014801:Vitamin A; D002338:Carotenoids; C029036:crocin; D011794:Quercetin; D005978:Glutathione