Sensitive ESR determination of intracellular oxidative stress by using acyl-protected hydroxylamines as new spin reagents

Several acyl-protected hydroxylamines were synthesized as new spin reagents for ESR measurements of intracellular oxidative stress. These compounds we re stable non-radical compounds, but were easily deprotected with esterase to yield hydroxylamines, which were oxidized by oxidants to yield ESR- dete ctable nitroxide radical. Using an acyl-protected hydroxylamine, a highly s ensitive ESR determination procedure was successfully conducted to analyze oxidative stress in human leukocytes.