DMPO Nitrone Adduct

Free radicals are highly reactive and generally short-lived species. Hence, most studies of free radicals have been restricted to analysis of end products formed following their interaction with cellular biomolecules. One technology that has permitted direct study of free radicals is electron spin resonance (ESR). For very short lived radicals, spin traps have been employed to generate longer lived radicals that are more amenable to ESR analysis. The most widely used of these spin traps is 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). The reaction of DMPO with a protein radical gives rise to a nitroxide radical which can be disproportionate to hydrozylamine and nitrone adducts. Of these species, only the nitrone adduct can be considered stable.