GC (Guanine‐Cytosine)‐Selective DNA‐Binding and Antitumor Activity of a QuercetinManganese(II) Complex

Abstract The DNA binding and cleavage properties of quercetinmanganese(II) complexes have been studied, but little attention has been devoted to the relationship between the antitumor activity of these complexes and the DNA‐binding properties. Here, the DNA binding properties of the quercetinmanganese(II) complex [Mn(Que) 2 (H 2 O) 2 ] were studied using UV/VIS and fluorescence spectroscopy and viscosity measurements. The results indicate that the complex was preferentially bound to DNA in the GC (guaninecytosine)‐rich regions via an intercalative mode. Furthermore, the cytotoxicity experiments confirmed its apoptosis‐inducing activity. We also demonstrated that the levels of survivin protein expression in HepG2 cells decreased and that the relative activity of caspase‐3 significantly increased after treatment with the complex. Hence, our results suggest that the antitumor activity of the [Mn(Que) 2 (H 2 O) 2 ] complex might be related to its intercalation into DNA and its DNA‐binding selectivity.