Comparative toxicity of [3]ferrocenophane and ferrocene moieties on breast cancer cells

Recent results suggest that [3]ferrocenophane may be an interesting motif in the development of cytotoxic anti-cancer agents. We here report the synthesis of three such compounds based on the 1-[(p-R-phenyl)-phenyl-methylidenyl)]-[3]ferrocenophane skeleton with R = OH, NH2 and NHC(O)CH3 substitution on one of the phenyl rings. Cytotoxicity studies show that these compounds are up to four times more powerful against hormone-independent breast cancer cells than their corresponding ferrocene analogs.