Ferrocene Derivatives as Histone Deacetylase Inhibitors: Synthesis and Biological Evaluation

Abstract

Ferrocene is an organometallic compound that has attracted considerable scientific interest due to its unique properties, including low toxicity, excellent stability in aqueous and aerobic media, and high lipophilicity, which enhances membrane permeability. The ferrocene moiety has been effectively used as a bioisostere of phenyl rings and heteroaromatic groups in the structures of approved tyrosine kinase inhibitors and histone deacetylase inhibitors (HDACis). HDACis exert their cytotoxic effects by blocking cyclin/CDK complexes, causing cell cycle arrest, inducing apoptosis, inhibiting angiogenesis, and through non-histone-directed mechanisms. This mini-review summarizes the synthesis and biological evaluation of small libraries of compounds in which a ferrocenyl moiety is incorporated into the structure of suberoylanilide hydroxamic acid (SAHA) and a number of analogues. The influence of the organometallic function on the antiproliferative effect is investigated. Both docking analysis and in vitro studies confirm that the ferrocenyl-modified HDACis exhibit potent cytotoxicity and strong inhibitory activity against the various enzyme isoforms.