A [3]Ferrocenophane Polyphenol Showing a Remarkable Antiproliferative Activity on Breast and Prostate Cancer Cell Lines

We have previously shown that modification of polyphenols with a ferrocenyl group call dramatically enhance their cytotoxicity. We now present two new [3]ferrocenophane compounds, one of which has an antiproliferative effect seven times stronger than the corresponding noncyclic species, with IC50 values of 90 and 94 nM on hormone-independent MDA-MB-231 breast and PC-3 prostate cancer cell lines, respectively. Solubility studies in water using methylated P-cyclodextrin and electron transfer studies are also presented.