Electrochemical oxidation of antitumor imidazoacridinone derivatives and the reference 2-hydroxyacridinone

Abstract

Abstract The electrochemical oxidation of antitumor-active 5-diethylaminoethylaminoimidazoacridinone derivatives as well as the reference acridinone analogs have been studied by cyclic voltammetry, spectroelectrochemical methods and controlled potential electrolysis to investigate the ability of imidazoacridinones to undergo oxidative metabolic activation in the organism. The cyclic voltammograms at a glassy-carbon electrode in water, pH = 7.4 show two closely spaced peaks for imidazoacridinones and one main peak for acridinones. The electrochemical processes appear to be irreversible for all compounds. Derivatives with the hydroxyl group in the position corresponding to position 2 of the acridinone molecule are easier to oxidize than the corresponding derivatives without the hydroxyl group. The studies of the reference 2-hydroxyacridinone in acetonitrile show electrochemical oxidation to be a diffusion controlled, chemically irreversible process. Two products of oxidation are formed during the forward potential scan and they react giving rise to that are reduced during the reverse scan. The first product of oxidation was isolated and identified as a dimer 1,1′-bi(2-hydroxyacridinone).