Organometallic Antitumor Compounds: Ferrocifens as Precursors to Quinone Methides

AbstractThe synthesis and chemical oxidation profile of a new generation of ferrocifen derivatives with strong antiproliferative behavior in vitro is reported. In particular, the hydroxypropyl derivative HO(CH2)3C(Fc)=C(C6H4OH)2 (3 b) exhibited exceptional antiproliferative activity against the cancer cell lines HepG2 and MDA‐MB‐231 TNBC, with IC50 values of 0.07 and 0.11 μM, respectively. Chemical oxidation of 3 b yielded an unprecedented tetrahydrofuran‐substituted quinone methide (QM) via internal cyclization of the hydroxyalkyl chain, whereas the corresponding alkyl analogue CH3CH2‐C(Fc)=C(C6H4OH)2 merely formed a vinyl QM. The ferrocenyl group in 3 b plays a key role, not only as an intramolecular reversible redox “antenna”, but also as a stabilized carbenium ion “modulator”. The presence of the oxygen heterocycle in 3 b‐QM enhances its stability and leads to a unique chemical oxidation profile, thus revealing crucial clues for deciphering its mechanism of action in vivo.

Organometallic Antitumor Compounds: Ferrocifens as Precursors to Quinone Methides Journal Articles