KINETICS AND MECHANISM OF PYROGALLOL AUTOXIDATION

The kinetics of pyrogallol autooxidation has been studied by single-sw eep oscillopolarography in Tris-HCl buffer soluton in the pH range 7.2 0 similar to 9.10. The reaction was first order to pyrogallol in the p resence of excess dissolved O-2, The focus was put on pyrogallol autoo xidation with products of semiquinone free radical and active oxygen. A mechanism was presented which explains the increase in rate with inc reasing pH by postulating that H2PYR- has a greater reactivity with di ssolved O-2 than H3PYR. The derived rate law is in good agreement with the experimental observations, The paper also presented a new assay f or superoxide dismutase and antioxidant activity of pharmaceuticals.