RESUMEN
Iridium(III) complexes of the type [Ir(η(5) -C5 Me5 )Cl2 {Ph2 PCH2 CH2 CH2 S(O)x Ph-κP}] (x=0-2; 1-3) and [Ir(η(5) -C5 Me5 )Cl{Ph2 PCH2 CH2 CH2 S(O)x Ph-κP,κS}][PF6 ] (x=0-1; 4 and 5) with 3-(diphenylphosphino)propyl phenyl sulfide, sulfoxide, and sulfone ligands Ph2 PCH2 CH2 CH2 S(O)x Ph were designed, synthesized, and characterized fully, including X-ray diffraction analyses for complexes 3 and 4. In vitro studies against human thyroid carcinoma (8505C), submandibular carcinoma (A253), breast adenocarcinoma (MCF-7), colon adenocarcinoma (SW480), and melanoma (518A2) cell lines provided evidence for the high biological potential of the neutral and cationic iridium(III) complexes. Neutral iridium(III) complex 5 proved to be the most active, with IC50 values up to about 0.1â µM, representing activities of up to one order of magnitude higher than cisplatin. Using 8505C cells, apoptosis was shown to be the main mechanism through which complex 5 exerts its tumoricidal action. The described iridium(III) complexes represent potential leads in the search for novel metal-based anticancer agents.
Asunto(s)
Antineoplásicos/química , Complejos de Coordinación/química , Iridio/química , Antineoplásicos/síntesis química , Antineoplásicos/farmacología , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/farmacología , Cristalografía por Rayos X , Humanos , Ligandos , Células MCF-7 , Conformación Molecular , Especies Reactivas de Oxígeno/metabolismo , Relación Estructura-ActividadRESUMEN
Neutral iridium(III) complexes of the type [Ir(η(5)-C5Me5)Cl2{Ph2PCH2S(O)xPh-κP}] (1-3) with diphenylphosphino-functionalized methyl phenyl sulfides, sulfoxides, and sulfones Ph2PCH2S(O)xPh (x = 0, L1; 1, L2; 2, L3) and the cationic complex [Ir(η(5)-C5Me5)Cl{Ph2PCH2SPh-κP,κS}][PF6] (4) were synthesized and fully characterized analytically and spectroscopically. Furthermore, the structure of 2 was determined by X-ray diffraction analysis. The biological potential of the neutral and cationic iridium(III) complexes was tested in vitro against the cell lines 8505C, A253, MCF-7, SW480 and 518A2. Complex [Ir(η(5)-C5Me5)Cl2{Ph2PCH2S(O)Ph-κP}] (2), with ligand L2 κP coordinated containing a pendent sulfinyl group, is the most active one (IC50 values of about 3 µM), thus, with activities comparable to cisplatin. Complex 2 proved to have an even a higher antiproliferative activity than cisplatin against 8505C and SW480 cell lines, used as a model system of highly anaplastic cancers with low sensitivity to conventional chemotherapeutics such as cisplatin. Additional experiments demonstrated that apoptosis and autophagic cell death contribute to the drug's tumoricidal action.