Biological Potential of Halfsandwich Ruthenium(II) and Iridium(III) Complexes.

In vitro studies with the ruthenium(II) and analogous iridium(III) complexes [Ru(eta(6)-p-cymene)-Cl-2{Ph2PCH2CH2CH2S(O)(x)Ph-kappa P}], [Ru(eta(6)-p-cymene)-Cl{Ph2PCH2CH2CH2S(O)(x)Ph-kappa P,kappa S}][PF6] (1-4), [Ir(eta(5)-C5Me5)Cl2{Ph2P-CH2CH2CH2S(O)(x)Ph-kappa P}] and [Ir(eta(5)-C5Me5)Cl{Ph2PCH2CH2CH2S(O)(x)Ph-kappa P,kappa S}][PF6] (5-8; x = 0, 1) revealed the high selectivity toward the 8505C, A253, MCF-7, SW480 and 518A2 cancer cell lines. Thus, the cationic ruthenium complex 4 proved to be the most selective one. In case of the neutral and cationic ruthenium complexes 1-4 the caspase-dependent apoptotic cell death was proven as the main cause of the drug's tumoricidal action on 8505C cell line.