Structure and cytotoxicity of zinc (II) and cobalt (II) complexes based on 1,3,5-tris(1-imidazolyl) benzene

Zinc Complexes with Nitrogen Donor Ligands as Anticancer Agents

The search for anticancer metal-based drugs alternative to platinum derivatives could not exclude zinc derivatives due to the importance of this metal for the correct functioning of the human body. Zinc, the second most abundant trace element in the human body, is one of the most important micro-elements essential for human physiology. Its ubiquity in thousands of proteins and enzymes is related to its chemical features, in particular its lack of redox activity and its ability to support different coordination geometries and to promote fast ligands exchange. Analogously to other trace elements, the impairment of its homeostasis can lead to various diseases and in some cases can be also related to cancer development. However, in addition to its physiological role, zinc can have beneficial therapeutic and preventive effects on infectious diseases and, compared to other metal-based drugs, Zn(II) complexes generally exert lower toxicity and offer few side effects. Zinc derivatives have been proposed as antitumor agents and, among the great number of zinc coordination complexes which have been described so far, this review focuses on the design, synthesis and biological studies of zinc complexes comprising N-donor ligands and that have been reported within the last five years.

Crystal structure of poly[bis(μ3-(1-(3,5-di(1H-imidazol-1-yl)phenyl)-1H-imidazole-κ3N:N′:N′′)cobalt(II)] dinitrate — N,N-dimethylformamide (1/4), C42H52N18O10Co

C42H52N18O10Co, monoclinic, P21/c (no. 14), a = 11.3692(7) Å, b = 17.5938(10) Å, c = 12.1825(7) Å, β = 108.6360(10)°, V = 2309.1(2) Å3, Z = 2, R gt(F) = 0.0308, wR ref(F 2) = 0.0765, T = 120(2) K.

Cobalt(II) Diphenylazodioxide Complexes Induce Apoptosis in SK-HEP-1 Cells

The cobalt(II) complex salts [Co(bpy)(az)₂](PF₆)₂ and [Co(az)₄](PF₆), each bearing the unusual cis-N,N'-diphenylazodioxide ligand, were both screened as possible anticancer agents against SK-HEP-1 liver cancer cells. Both compounds were found to induce substantial apoptosis as an increasing function of concentration and time. Measurement of apoptosis-related proteins indicated that both the extrinsic and intrinsic pathways of apoptosis were activated. The apoptotic activity induced by these salts is not displayed either by simple cobalt(II) salts or complexes or by the free nitrosobenzene ligand. Additionally, these compounds did not induce apoptosis, as assessed by poly(adenosine diphosphate-ribose) polymerase cleavage, in several other cell lines.