Cytotoxic activity and protein binding through an unusual oxidative mechanism by an iridium(<scp>i</scp>)–NHC complex

Abstract

A new NHC iridium(I) complex (1) showing significant antiproliferative properties in vitro is described here. Its crystal structure, solution behaviour and interactions with the model proteins cytochrome c (cyt c) and lysozyme were investigated. High resolution ESI-MS measurements suggest that this iridium(i) complex acts as a prodrug and binds cyt c tightly through an unusual "oxidative" mechanism. Eventually, an iridium(III)-NHC fragment is found associated to the protein.