Ascorbic acid: a scavenger of superoxide radical.
The second order rate constant for the reaction between ascorbic acid and superoxide at pH 7.4 using the xanthine-xanthine oxidase system was estimated to be 5.4 x 10(6) M-1 sec-1. The results indicate that the efficacies of superoxide dismutase and ascorbic acid for catalyzing the decay of superoxide radical in animal tissues are similar. The significance of ascorbic acid as a scavenger of superoxide is discussed from the point of view of evolution of ascorbic acid synthesizing capacity in the terrestrial vertebrates.
D000818:Animals; D001001:Anura; D001205:Ascorbic Acid / Q000378:metabolism*; D005399:Fishes; D005609:Free Radicals; D005978:Glutathione / Q000494:pharmacology; D008433:Mathematics; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism*
D005609:Free Radicals; D013481:Superoxides; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid