Purity >98%. Pyrogallol is a natural oxidant that can generate superoxide (O2 - ) in alkaline solutions through autoxidation to a semiquinone radical. Importantly, the semiquinone radical can react with O2 - in an acidic environment to produce a quinone and H2 O2 . Pyrogallol autoxidation is used in superoxide dismutase activity assays. It can also be used in assays to assess antioxidant capacity. Pyrogallol is used in some biological systems as an O2 - scavenger. In other biological systems, it is used as an O2 - generator. Pyrogallol effectively scavenges DPPH radical and ABTS+ in vitro . Pyrogallol is a product of tannin degradation to gallic acid by ruminant microbes and has hepatotoxic and nephrotoxic effects in vivo .