Iron can be a detrimental catalyst in biological free radical oxidations. Because of the high physiological ratio of [O2]/[H2O2] (> or = 10(3)), we hypothesize that the Fenton reaction with pre-existing H2O2 is only a minor initiator of free radical oxidations and that the major initiators of biological free radical oxidations are the oxidizing species formed by the reaction of Fe2+ with dioxyg...

Electron spin resonance spectroscopy has been used to study free radical generation in rats with acute sodium formate poisoning. The in vivo spin-trapping technique was used with alpha-(4-pyridyl-1-oxide)-N-t-butylnitrone (POBN), which reacts with free radical metabolites to form radical adducts, which were detected in the bile and urine samples from Fischer rats. The use of [(13)C]-sodium form...

The formation of alpha-dicarbonyl compounds seems to be an important step for cross-linking proteins in the glycation or Maillard reaction. To elucidate the mechanism for the cross-linking reaction, we studied the reaction between a three-carbon alpha-dicarbonyl compound, methylglyoxal, and amino acids. Our results showed that this reaction generated yellow fluorescent products as formed in som...

Ascorbic Acid, Dehydroascorbic Acid, Redox Potential, Free Radical, ESR The previously reported interaction between ascorbate monoanion and dehydroascorbic acid yielding semidehydroascorbic acid has been shown to be thermodynamically unfeasible and non-existent. No evidence for radical for­ mation in the reinvestigation of the reaction using ESR spectroscopy under careful exclusion of air could...