Kinetic Investigations of the Autoxidation of Adrenalin

Abstract

Generation rates of superoxide anions (O2 -) by autoxidizing adrenalin at pH 9.5 were deter­mined in solutions containing either superoxide dismutase (0.85 м-1 s-1) or hydroxylamine (0.0185 м-1 s-1) as competitive scavengers. The rate constants of O2 - with adrenalin and hydroxyl­amine were calculated for neutral and alkaline solutions. The respective values were for adrenalin: 5.6 ×104 м-1 s-1, pH 7.8; 7.0 × 103 м-1 s-1, pH 9.5 - and for hydroxylamine 5.9 × 104 м-1 s-1, pH 7.8; 3.4 ×104 м-1 s-1, pH 9.5. The effects of various competitors and O2 --sources on the rate constants were compared.