Pyrogallol is a natural oxidant that can generate superoxide (O2-) in alkaline solutions through autoxidation to a semiquinone radical.1 Importantly, the semiquinone radical can react with O2- in an acidic environment to produce a quinone and H2O2.1 Pyrogallol autoxidation is used in superoxide dismutase activity assays.1 It can also be used in assays to assess antioxidant capacity.2,3 Pyrogallol is used in some biological systems as an O2- scavenger.4 In other biological systems, it is used as an O2- generator.5,6 Pyrogallol effectively scavenges DPPH radical and ABTS+ in vitro.7 Pyrogallol is a product of tannin degradation to gallic acid by ruminant microbes and has hepatotoxic and nephrotoxic effects in vivo.8
1.Magnani, L., Gaydou, E.M., and Hubaud, J.C.Spectrophotometric measurement of antioxidant properties of flavones and flavonols against superoxide anionAnal. Chim. Acta411209-216(2000) 2.Li, X.Improved pyrogallol autoxidation method: A reliable and cheap superoxide-scavenging assay suitable for all antioxidantsJ. Agric. Food. Chem.60(25)6418-6424(2012) 3.Chang, C.S., Chang, C.L., and Lai, G.H.Reactive oxygen species scavenging activities in a chemiluminescence model and neuroprotection in rat pheochromocytoma cells by astaxanthin,βcarotene, and canthaxanthinKaohsiung J. Med. Sci.29(8)412-421(2013) 4.Wang.T., Lin, H., Tu, Q., et al.Fisetin protects DNA against oxidative damage and its possible mechanismAdv. Pharm. Bull.6(2)267-270(2016) 5.Sindler, A.L., Reyes, R., Chen, B., et al.Age and exercise training alter signaling through reactive oxygen species in the endothelium of skeletal muscle arteriolesJ. Appl. Physiol.114(5)681-693(2013) 6.Moreno-Manzano, V., Ishikawa, Y., Lucio-Cazana, J., et al.Selective involvement of superoxide anion, but not downstream compounds hydrogen peroxide and peroxynitrite, in tumor necrosis factor-α-induced apoptosis of rat mesangial cellsJ. Biol. Chem.275(17)12684-12691(2000) 7.Mathew, S., Abraham, T.E., and Zakaria, Z.A.Reactivity of phenolic compounds towards free radicals under in vitro conditionsJ. Food. Sci. Technol.52(9)5790-5798(2015) 8.Reed, J.D.Nutritional toxicology of tannins and related polyphenols in forage legumesJ. Anim. Sci.73(5)1516-1528(1995)