A combined EPR spectroscopy and DFT-based structural interpretation of the antitumor properties of oxindolimine-copper(II) complexes

Abstract

Some oxindolimine-copper(II) complexes have been designed and investigated as potential antitumor compounds, inhibiting significantly diverse tumor cell growth, and having as main targets DNA, and crucial proteins, as topoisomerases and kinases. Binding efficiently to DNA, they induce apoptosis by an oxidative mechanism. As lipophilic cations they also act as decoupling agents in the mitochondria, depleting the membrane potential. All those properties are direct consequences of their structural characteristics and geometry around the coordination center. By using a combination of DFT calculations and structural EPR spectroscopic data, we managed to rationalize experimental data, and uncover key factors affecting their reactivity.