Photosensitization by Antitumoragents–6. Production of Superoxide Radical and Hydrogen Peroxide During Illumination of Diaminoanthracenediones in the Presence of Nadh in Aqueous Solutions: An Epr Study

Photosensitizing capabilities of anthracenedione anticancer agents to oxidize NADH in aqueous solutions have been studied by EPR and spin trapping techniques. It is demonstrated that 1,4‐diamino substituted anthraquinones, like mitoxantrone and ametantrone, do not photosensitize NADH oxidation while 1,5‐ and l,8‐bis[[(diethylamino)ethyl]amino]anthraquinones do, undergoing simultaneous one‐electron reduction to their semiquinone radical forms upon illumination with visible light. In aerated aqueous solutions the reaction leads to the production of superoxide ion and hydrogen peroxide.