[Generation of superoxide anion radicals and hydrogen peroxide in the auto-oxidation of caffeic acid].
Caffeic acid (5-200 mkM) reduces cytochrome c during autoxidation in potassium phosphate buffer, pH 7-8. The reduction is inhibited by superoxide dismutase, which suggests generation of superoxide anion radicals. The generation rate is 0.028-0.115 mkmoles O2- per min. Superoxide appears to be a side product of the reaction, since the autoxidation of caffeic acid itself (followed by A420) is not inhibited by superoxide dismutase. The autoxidation is accompanied by oxygen of consumption. An addition of catalase results in liberation of some part of consumed oxygen, this being indicative of accumulation of hydrogen peroxide. Caffeic acid is known to be responsible for the resistance of plants to parasites because of its toxicity. This function presumably depends on superoxide or other reactive oxygen species.
D002109:Caffeic Acids; D002374:Catalase / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D002934:Cinnamates; D003574:Cytochrome c Group / Q000378:metabolism*; D006861:Hydrogen Peroxide; D007700:Kinetics; D010084:Oxidation-Reduction; D010100:Oxygen; D010101:Oxygen Consumption; D013053:Spectrophotometry; D013481:Superoxides
D002109:Caffeic Acids; D002934:Cinnamates; D003574:Cytochrome c Group; D013481:Superoxides; D006861:Hydrogen Peroxide; D002374:Catalase; D010100:Oxygen
Generatsiia superoksidnykh anion-radikalov i perekisi vodoroda pri Avtookislenii kofeĭnoĭ kisloty.