A New Age for Iron: Antitumoral Ferrocenes

Abstract

From the core of the earth to the core of the archetypal organometallic compound ferrocene, iron and its compounds contribute to create many aspects of our reality: the earth’s magnetism, hemoglobin’s respiratory function, and a myriad of life-essential biochemical reactions. This review deals with synthetic iron compounds from the literature, in particular ferrocene and derivatives, which are potential new anticancer agents. Cytotoxic ferrocenes are among the most promising metal-based drugs for cancer chemotherapy. There is a vast range of reported compounds, herein classified into three categories, according to their chemical nature and supramolecular organization. The first comprises ferrocenium salts and ferrocene derivatives, from simple functionalized ferrocenes to elaborate iron-based mimics of organic drugs, the second includes heterometallic complexes (with two or more metal centers), in which ferrocene has the role of an ancillary ligand, and the third comprises cytotoxic ferrocenes associated with carrier systems, namely aqueous-soluble polymers, multilayer micelles, and cyclodextrins.