Synthesis, characterization, DNA interaction studies, and biological evaluation of copper(II) hybrids containing azole drugs and intercalating ligands against neglected diseases

In an attempt to treat neglected diseases such as leishmaniasis and fungal infections, three novel copper(II) hybrid have been developed: [Cu(dppz)(CTZ)(NO3)](NO3) (1), [Cu(dppz)(KTZ)(H2O)(NO3)](NO3) (2), and [Cu(dppz)(FLZ)(NO3)]2(NO3)2 (3). They were synthesized by coordinating antifungal imidazole based drugs and dipyridophenazine as ligands to copper(II) under mild conditions and in good yields. These coordination compounds were characterized by various analytical and spectroscopic techniques which confirmed the coordination of both ligands to the metal, and the monodentate (1) or bidentate (2 and 3) coordination of the nitrate and as counterion. These copper hybrids were stable in solid state, in dimethyl sulfoxide (DMSO) and the DMSO-water mixture. DNA interactions were studied using absorption and fluorescence titrations, viscosity measurements, and electrophoresis assays. Complexes 1 and 2 formed strong interaction with DNA. The activity against Leishmania was the highest with complex 3, unlike against Sporothrix brasiliensis, where the free imidazole-based drugs (ITZ and KTZ) performed better.