Mono- and polynuclear complexes of Pt(II) with polypyridyl ligands. Synthesis, spectroscopic and structural characterization and cytotoxic activity.
An array of poly- and mononuclear complexes of Pt(II) with polypyridyl ligands is reported. The framework complexes [(PtCl(2))(2)(bpp)(2)(micro-PtCl(2))](H(2)O)(2) [bpp=2,3-bis(2-pyridyl)pyrazine], [PtCl(2)(micro-tptz)PtClNCPh]Cl [tptz=2,4,6-tris(2-pyridyl)-1,3,5-triazine], and mononuclear PtCl(2)(NH(2)dpt) [NH(2)dpt=4-amino-3,5-bis(2-pyridyl)-1,2,4-triazole] have been prepared and structurally characterized. Both neutral and ionic complexes are present, with bifunctional and monofunctional Pt(II) moieties, whose size and shape enable them to behave as novel scaffolds for DNA binding. Pt(II) complexes were tested for their biological activity. Cell viability assay and flow cytometric analysis demonstrated that these complexes, particularly [PtCl(2)(micro-tptz)PtClNCPh]Cl, were effective death inducers in human colon rectal carcinoma HT29 cells and their cytotoxic activity was higher than that exerted by cisplatin. Morphological analysis of treated HT29 cells, performed by fluorescence microscopy after Hoechst 33258 staining, showed the appearance of the typical features of apoptosis. Moreover, our results suggested that mitochondria are involved in apoptosis induced by Pt(II) complexes in HT29 cells as demonstrated by dissipation of mitochondrial transmembrane potential.
Dipartimento di Chimica Inorganica ed Analitica S. Cannizzaro, Università degli Studi di Palermo, Viale delle Scienze, Parco d'Orleans, 90128 Palermo, Italy.
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D000970:Antineoplastic Agents / Q000737:chemistry*; D002453:Cell Cycle; D005434:Flow Cytometry; D019073:HT29 Cells; D006801:Humans; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*
D000970:Antineoplastic Agents; D008024:Ligands; D011725:Pyridines