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

In vitro studies with the ruthenium(II) and analogous iridium(III) complexes [Ru(η6- p-cymene)Cl2{Ph2PCH2CH2CH2S(O)xPh-ΚP}], [Ru(η6-p-cymene)Cl{Ph2PCH2CH2CH2S(O)xPh- ΚP,ΚS}][PF6] (1–4), [Ir(η5-C5Me5)Cl2{Ph2PCH2CH2CH2S(O)xPh-ΚP}] and [Ir(η5-C5Me5)Cl{Ph2 PCH2CH2CH2S(O)xPh-ΚP,ΚS}][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.