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- Augusto, Ohara, et al.
(författare)
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Carbon dioxide-catalyzed peroxynitrite reactivity - The resilience of the radical mechanism after two decades of research
- 2019
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Ingår i: Free Radical Biology & Medicine. - : ELSEVIER SCIENCE INC. - 0891-5849 .- 1873-4596. ; 135, s. 210-215
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Forskningsöversikt (refereegranskat)abstract
- Peroxynitrite, ONOO-, formed in tissues that are simultaneously generating NO center dot and O-2(center dot-), is widely regarded as a major contributor to oxidative stress. Many of the reactions involved are catalyzed by CO2 via formation of an unstable adduct, ONOOC(O)O-, that undergoes O-O bond homolysis to produce NO2 center dot and CO3 center dot- radicals, whose yields are equal at about 0.33 with respect to the ONOO- reactant. Since its inception two decades ago, this radical-based mechanism has been frequently but unsuccessfully challenged. The most recent among these [Serrano-Luginbuehl et al. Chem. Res. Toxicol. 31: 721-730; 2018] claims that ONOOC(O)O- is stable, predicts a yield of NO2 center dot/CO3 center dot- of less than 0.01 under physiological conditions and, contrary to widely accepted viewpoints, suggests that radical generation is inconsequential to peroxynitrite-induced oxidative damage. Here we review the experimental and theoretical evidence that support the radical model and show this recently proposed alternative mechanism to be incorrect.
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