Recent advances in the chemistry of iron-based chemotherapeutic agents

The discovery of cisplatin followed by its success in anticancer therapy laid the foundation of metal-based drug design and development. Further research led to discovery of other platinum containing complexes, namely, carboplatin and oxaliplatin. The disadvantages of the platinum-based drugs are their untoward side effects and drug resistance. This paved way for new metal-based anticancer drugs with a prospect for iron-based anticancer agents. Initial interest on the anticancer activities of iron complexes stemmed from the prolific activities reported for naturally occurring iron-bleomycins and ferrocenium salts like ferrocenium picrate and trichloroacetate. Their efficacy was ascribed to the disruption of the oxidative homeostasis in cancer cells causing oxidative DNA damage. In this review, the early developments of iron complexes as chemotherapeutic agents that eventually encouraged further advances in the field of cancer therapy and diagnostics, rendering them as promising candidates for further research are presented. The aspects of photocytotoxicity, including the photo-release of active molecules, redox activity, organometallic complexes and multinuclearity of anticancer iron complexes are highlighted. We have concluded our review with a discussion on the existing hurdles and the prospective solutions for the development of iron-based anticancer agents. (C) 2020 Elsevier B.V. All rights reserved.