1359998-79-0Relevant academic research and scientific papers
Structure-activity relationships in cytotoxic AuI/Au III complexes derived from 2-(2′-pyridyl)benzimidazole
Maiore, Laura,Aragoni, Maria Carla,Deiana, Carlo,Cinellu, Maria Agostina,Isaia, Francesco,Lippolis, Vito,Pintus, Anna,Serratrice, Maria,Arca, Massimiliano
, p. 4068 - 4080 (2014/05/06)
Gold(I) and gold(III) complexes derived from 2-(2′-pyridyl) benzimidazole (pbiH) were proven to be a promising class of in vitro antitumor agents against A2780 human ovarian cancer cells. In this paper, a comparative electrochemical, UV-vis absorption, and emission spectroscopic investigation is reported on pbiH, the two mononuclear AuIII complexes [(pbi)AuX 2] (X = Cl (1), AcO (2)), the four mononuclear AuI derivatives [(pbiH)AuCl] (3), [(pbiH)Au(PPh3)]PF6 ((4 +)(PF6-)), [(pbi)Au(PPh3)] (5), and [(pbi)Au(TPA)] (6), the three mixed-valence AuIII/AuI complexes [(μ-pbi)Au2Cl3] (7), [(Ph3P) Au(μ-pbi)AuX2]PF6 (X = Cl ((8+)(PF 6-)), AcO ((9+)(PF6-))), and the binuclear AuI-AuI compound [(μ-pbi)Au 2(PPh3)2]PF6 ((10 +)(PF6-)). All complexes feature irreversible reduction processes related to the AuIII/AuI or Au I/Au0 processes and peculiar luminescent emission at about 360-370 nm in CH2Cl2, with quantum yields that are remarkably lower ((0.7-14.5) × 10-2) in comparison to that determined for the free pbiH ligand (31.5 × 10-2) in the same solvent. The spectroscopic and electrochemical properties of all complexes were interpreted on the grounds of time-dependent PBE0/DFT calculations carried out both in the gas phase and in CH2Cl2 implicitly considered within the IEF-PCM SCRF approach. The electronic structure of the complexes, and in particular the energy and composition of the Kohn-Sham LUMOs, can be related to the antiproliferative properties against the A2780 ovarian carcinoma cell line, providing sound quantitative structure-activity relationships and shedding a light on the role played by the global charge and nature of ancillary ligands in the effectiveness of Au-based antitumor drugs.
Synthesis, structural characterization, solution behavior, and in vitro antiproliferative properties of a series of gold complexes with 2-(2′-pyridyl)benzimidazole as ligand: Comparisons of gold(III) versus gold(I) and mononuclear versus binuclear derivatives
Serratrice, Maria,Cinellu, Maria A.,Maiore, Laura,Pilo, Maria,Zucca, Antonio,Gabbiani, Chiara,Guerri, Annalisa,Landini, Ida,Nobili, Stefania,Mini, Enrico,Messori, Luigi
, p. 3161 - 3171 (2012/04/23)
A variety of gold(III) and gold(I) derivatives of 2-(2′-pyridyl) benzimidazole (pbiH) were synthesized and fully characterized and their antiproliferative properties evaluated in a representative ovarian cancer cell line. The complexes include the mononuclear species [(pbi)AuX2] (X = Cl, 1; OAc, 2), [(pbiH)AuCl] (3), [(pbiH)Au(PPh3)][PF6] (4-PF6), and [(pbi)Au(L)] (L = PPh3, 5; TPA, 6), and the binuclear gold(I)/gold(I) and gold(I)/gold(III) derivatives [(PPh 3)2Au2(μ2-pbi)][PF6] (10-PF6), [ClAu(μ3-pbi)AuCl2] (7),and [(PPh3)Au(μ3-pbi)AuX2][PF6] (X = Cl, 8-PF6; OAc, 9-PF6). The molecular structures of 6, 7, and 10-PF6 were determined by X-ray diffraction analysis. The chemical behavior of these compounds in solution was analyzed both by cyclic voltammetry in DMF and absorption UV-vis spectroscopy in an aqueous buffer. Overall, the stability of these gold compounds was found to be acceptable for the cellular studies. For all complexes, relevant antiproliferative activities in vitro were documented against A2780 human ovarian carcinoma cells, either resistant or sensitive to cisplatin, with IC50 values falling in the low micromolar or even in the nanomolar range. The investigated gold compounds were found to overcome resistance to cisplatin to a large degree. Results are interpreted and discussed in the frame of current knowledge on cytotoxic and antitumor gold compounds.
