Oxidation of ethidium-based probes by biological radicals: mechanism, kinetics and implications for the detection of superoxide.

ABSTRACT: Hydroethidine (HE) and hydropropidine ([Formula: see text]) are fluorogenic probes used for the detection of the intra- and extracellular superoxide radical anion ([Formula: see text]). In this study, we provide evidence that HE and [Formula: see text] react rapidly with the biologically relevant radicals, including the hydroxyl radical, peroxyl radicals, the trioxidocarbonate radical anion, nitrogen dioxide, and the glutathionyl radical, via one-electron oxidation, forming the corresponding radical cations. At physiological pH, the radical cations of the probes react rapidly with [Formula: see text], leading to the specific 2-hydroxylated cationic products. We determined the rate constants of the reaction between [Formula: see text] and the radical cations of the probes. We also synthesiz

SUBMITTER: Michalski R 

PROVIDER: S-EPMC7596101 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature