Studies on platinum(II) and platinum(IV) complexes of some benzimidazole derivatives

In this study, four Pt(II) complexes with the structures [PIL2CI2], [PtL2Cl2] bearing 2-hydroxymetiiylbenzimidazole or 5(6)-chloro-2- hydroxymethyl benzirnidazole ligands as carrier ligand and six Pt(IV) complexes with the structures [PtL2CI2], [PtL2Cl2(OH)2], [PtL2Cl2(OCOCH3)2] bearing -chloro or -hydroxyl or -acetato groups as axial ligands were synthesized. In vitro cytotoxic activity of the complexes synthesized were tested against the human HeLa (cervixs adenocarcinom) and MCF-7 (breast cancer) cell lines using Cell Culture method. Carrier-ligands were obtained by condensation of glycolic acid with 1,2-phenylendiamine or 4^rdoro-l,2-phenylendiamine in the presence of 5 N hydrochloric acid. The Pt(II) complexes were synthesized by the reaction of the carrier-ligands with potassium tetrachloroplatinate or potassium tetraiodoplatinate in ethanol-water. The PuTV) complexes were synthesized by the reaction of the Pt(II) complexes with acetic acid or acetic acid anhydride or hydrogen peroxide. The chemical structures of the PuTQ and PuTV) complexes were characterized by their elemental analysis and IR and ^-NMR spectra. In general, among the complexes tested against HeLa (cervixs adenocarcinorri) and MCF-7 (breast cancer) cell lines the complexes bearing 2-hydroxymemylbenzünidazole carring-ligands were found tobe more active than the complexes bearing 5(6)-chloro-2- hy&oxymemylbenzimidazole ligands and it was also found that the Pt(II) complexes were more active than the Pt(TV) complexes. Compound 1 and 2 were found tobe active on the HeLa (cervixs adenocarcinom) cell line at 20 uM concentration and compound 1, 2, 4, 7 and 8 were found to be active on the MCF-7 (breast cancer) cell line at 20, 10, 20, 20, 20 uM concentration respectively. The complexes, which were found to be less active than cisplaün, exhibited moderate cyctotoxicity comparable to carboplatin on the HeLa (cervixs adenocarcinom) and MCF-7 (breast cancer).