Oxidative stress is defined as the imbalance between reactive species such as free radicals and oxidants and the antioxidant defenses. Free radicals are molecules with one or more unpaired electrons, while oxidants are molecules with a high potential for taking electrons from other molecules. The more recognized reactive species are the reactive oxygen species (ROS), which include oxygen and it...

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...

With a variety of forms of ischemic and toxic tissue injury, cellular accumulation of Ca2+ and generation of oxygen free radicals may have adverse effects upon cellular and, in particular, mitochondrial membranes. Damage to mitochondria, resulting in impaired ATP synthesis and diminished activity of cellular energy-dependent processes, could contribute to cell death. In order to model, in vitro...

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...