Metal-NHC complexes: a survey of anti-cancer properties

Abstract

New weapons to fight cancer are constantly needed. Among chemotherapeutics, anti-cancer metal-drugs have enjoyed a long and successful history since the discovery of the benchmark cisplatin. Advances in metal-drug discovery have motivated chemists to build plethora of complex structures. Among them, a novel area is emerging. This article presents a survey of the metal-N-Heterocyclic Carbenes (Ag(I), Au(I), Pd(II) and Cu(I)-NHCs) as potential anti-cancer agents. Most of the metal-NHCs considered display higher cytotoxicities than the reference metallo-drug cisplatin. Some of them are even selective for particular cell lines. Their mechanisms of action at the cellular level are further discussed, showing that the nature of the metal is of great importance. All these promising results demonstrate that this approach deserves more attention and work.

Enhanced cytotoxicity of silver complexes bearing bidentate N-heterocyclic carbene ligands

“…The counterion is expected to affect complex solubility and possible transmembrane diffusion, though this is likely to be very subtle and the fact that all the complexes are cationic gives them similar properties. AgBr, AgPF 6 and imidazolium salts 1a and 2a exhibit IC 50 values above 100 μM, which was the highest concentration tested for these compounds, hence the synergistic effect of both the silver centre and the NHC ligand clearly has a role in the cytotoxicity of silver NHCs.…”

“…[1][2][3][4] To a much lesser extent they have been investigated in biomedical applications, showing promise as antimicrobial (silver-NHCs) and as antitumour agents. [5][6][7] The antimicrobial properties of silver are well established and have resulted in silver being incorporated into several materials such as wound dressings, creams, deodorants and even clothing. [8][9][10] The toxicity of silver is thought to be relatively low which has enabled its wide use.…”

“…Specifically, NHC complexes of palladium, copper, gold and silver have been reported which exhibit cytotoxicity against various cancer cell lines. 6,12,[14][15][16] Most of the cytotoxic silver NHCs reported are neutral complexes, bearing a monodentate NHC donor and an acetate ligand (Fig. 1A).…”

Beyond catalysis: N-heterocyclic carbene complexes as components for medicinal, luminescent, and functional materials applications

“…11 A number of metals have shown cytotoxicity when bound to an NHC ligand. Specifically, 120 palladium, copper, silver, and gold complexes have been developed that display antitumor activities that largely surpass that of cisplatin (Fig.…”

Synthesis and Cytotoxicity of Dinuclear Silver(I)-N-Heterocyclic Carbene Complexes

“…The incorporation of Carboplatin against cancer has recently attracted researchers to further explore the area of metal based anticancer drugs [2,3]. Except transition metals, the organometallic compounds based on coinage metals (Ag, Au, Cu) have now attracted the researchers for medicinal applications [4,5].…”