Peroxynitrite radical ends

At physiological pH, ONOO- protonates to peroxynitrous acid (ONOOH) which disappears within a few seconds, the end product being largely nitrate. The chemistry of peroxynitrite/peroxynitrous acid is extremely complex, although addition of ONOO to cells and tissues leads to oxidation and nitration of proteins, DNA and lipids with a reactivity that is comparable to that of hydroxyl radicals. 

EPR s nal it does not contain free radicals. When O2 is injected into NO"-saturated 2-methylbutane, no color appears. Sometimes, a marginal EPR signal similar to the one found with the apparatus described above is detected. Injection of NO into N2-saturated 2-methylbutane likewise does not cause any color to show up, making sure that the red material results from reactions of O2 with NO. Despite the cmde method, we can provide solid arguments that the colored intermediate represents substantial amounts of the initial reactants. It may be a product of dead-end equilibria and not a stepping stone in the overall course of the autoxidation reaction, but hardly a minor contribution. Until to date, no molecule composed of N and O atoms only has been ft)und that has an extinction coefficient larger than 1000 cm in the visible spectral range. Peroxynitrite has an absorption maximum with... 

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