Oxidation of the selected probes for detection of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in aqueous solutions of nitric oxide donors

Production of reactive oxygen species (ROS): superoxide radical anion, hydrogen peroxide, hypohalous acids and reactive nitrogen species (RNS): nitric oxide, nitrogen dioxide, peroxynitrite etc. in living organisms is a central phenomenon of redox biology. In order to understand how those oxidants and radicals contribute to cellular signaling and pathologies, it is important to know what kind of species is produced, where and in what quantity. During the last thirty years a tremendous progress in understanding of the biological chemistry of ROS and RNS was done but their intracellular detection and quantitation still remains a challenge. A great variety of small molecule fluorogenic probes are available for the detection of ROS and RNS in cells, but their rational use requires a deep understanding of the mechanism of their action. In many cases probes are oxidized to the corresponding fluorescent products via radical intermediates. Determination of the reactivity of probe-derived radicals is of great importance for understanding of reaction mechanisms and proper interpretation of experimental data. Here we present the results of our study on the oxidation of selected fluorogenic probes in the aerated aqueous solutions of nitric oxide donors.