Copper(II) Nitroaromatic Schiff Base Complexes: Synthesis, Biological Activity and Their Interaction with DNA and Albumins

Abstract

Copper(II) complexes of the Schiff base ligands 2-((5-nitrofuran-2-yl)methyleneamino) phenol (HL1) and 2-(4-nitrobenzylideneamino)phenol (HL2) were prepared and characterized using physicochemical and spectroscopic techniques. In these complexes the Schiff base ligands acted as a bidentate donor bound to Cu 2+ through the oxygen and nitrogen atoms in the deprotonated form. The electron paramagnetic resonance spectra, carried out on [CuCl(L1)(phen)].0.5H 2 O and [CuCl(L2)(phen)].2H 2 O complexes, showed the presence of only mononuclear forms. The Cu 2+ complexes and ligands were evaluated for their in vitro trypanocidal activity. The complex [CuCl(L1)(phen)].0.5H 2 O was more active than the free Schiff base and also presented a superior effect to benznidazole, the reference drug. The antiproliferative activity of the Schiff bases and Cu 2+ complexes were evaluated for their effect on seven tumor cell lines and showed a cytostatic and in some cases a cytotoxic effect. These compounds also presented binding properties to deoxyribonucleic acid (DNA) and moderate ability to quench the intrinsic fluorescence of albumins.

Schiff bases and their metal complexes as urease inhibitors – A brief review

“…Schiff bases also exhibit a wide variety of biological activities, including antifungal, antibacterial, antitumor, anti-inflammatory, trypanocidal, anti-HIV, antimalarial, and anti-urease activities (reviewed by [1] , [6] , [7] , [8] , [9] , [10] , [11] ). Indeed, the imine group present in these compounds is critical for their biological activities [12] , and thus that moiety has been extensively explored for the development of new bioactive substances [13] , [14] , [15] , [16] , [17] .

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