Carbonate radical anion (CO3•−)

The carbonate radical anion (CO3•−) is a potent and selective one-electron oxidant that plays a critical role in the biochemistry of oxidative stress and cellular damage. It is primarily generated in vivo through the reaction of peroxynitrite (ONOO−) with carbon dioxide (CO2), a process facilitated by the high physiological concentration of bicarbonate buffers. It can also be produced via the peroxidative activity of enzymes such as copper-zinc superoxide dismutase (SOD1) and xanthine oxidase, or by the reaction of hydroxyl radicals with bicarbonate. Unlike the highly reactive and non-selective hydroxyl radical, the carbonate radical specifically targets electron-rich amino acid residues such as tryptophan, tyrosine, and methionine, and is a major cause of guanine oxidation in DNA. These modifications are implicated in various pathological states, including chronic inflammation, atherosclerosis, and neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and Alzheimer’s disease. From a therapeutic perspective, the carbonate radical is not a traditional protein target but rather a reactive species whose neutralization by antioxidant scavengers like melatonin, uric acid, and synthetic nitroxides is a focus of research for mitigating oxidative damage.

Other names

Carbonate radicalTrioxidocarbonate(1-) radicalCarbonate(•1−)Carbonate anion radical

One-electron reduction and radical scavenging