Peroxynitrite, Hydrogen peroxide

Peroxynitrite (ONOO⁻) is a highly reactive ion formed by the reaction of nitric oxide (NO) with superoxide (O₂●⁻). It is a reactive nitrogen species capable of oxidizing lipids, proteins, and nucleic acids, contributing to both cell signaling and cellular damage. Hydrogen peroxide (H₂O₂) is a small, stable, but reactive oxygen species commonly produced during cellular metabolism. It acts as both a signaling molecule at low concentrations and a mediator of oxidative damage at higher concentrations. Both species are involved in various physiological and pathological processes, primarily via induction of oxidative/nitrosative stress and modification of biomolecules. Elevated levels are implicated in inflammatory diseases, cardiovascular disorders, neurodegeneration, and certain cancers. There are no direct drugs for these molecules, but various antioxidants and scavengers are studied for their ability to mitigate their cellular effects.

Other names

PeroxonitriteONOO⁻peroxynitrous acid (protonated form)ONOOHH₂O₂peroxide

Antioxidants or scavengers act via direct reduction, radical quenching, or enhancing cellular antioxidant defenses. No direct "targeting" mechanisms because these are not traditional protein targets.