Diverse Structural Roles of Ferrocene in Mediating Ferroptosis Induction by ML162

Abstract

Ferroptosis, an iron-dependent form of regulated cell death, represents a compelling target for cancer therapy. A key cellular defense is mediated by glutathione peroxidase 4 (GPX4), where covalent inhibitors like ML162 act as potent ferroptosis inducers. To probe the correlation between ferrocene and ferroptosis, we systematically explored its diverse structural effects by designing and synthesizing three distinct series of ferrocene-incorporated ML162 derivatives. Among the derivatives, severalnotably I-6 and the biferrocene-based II-3-exhibited significantly enhanced ferroptosis-inducing activity in HT1080 cells; their high selectivity was validated through specific inhibition by Fer-1. Molecular docking studies revealed that the compounds engage the GPX4 active site through crucial covalent and non-covalent interactions. This finding was complemented by a cell-free assay, where lead compound II-3 demonstrated substantial Fenton-like reactivity, corroborating its dualmechanism design. Taken together, this work elucidates the diverse structural roles of ferrocene in mediating and potentiating ferroptosis induction by ML162, highlighting the significance of ferrocene hybridization in expanding chemical diversity and efficacy of metallodrugs.