Structures and Interaction with DNA of Ternary Palladium(II) Complexes: [Pd(Gly)(X)] (Gly=Glycine; X=2,2′-Bipyridine, 1,10-Phenanthroline and 2,2′-Bi-pyridylamine)

Abstract

Following the discovery of cis-diamminedichloroplatinum(II) (cisplatin) as the successful antitumor drug, 1) the research of the design and synthesis of novel platinum(II) complexes, having more favorable antitumor activities as compared with cisplatin, has been continued. [2][3][4][5] Palladium(II) complexes have been also investigated for developing the new antitumor agents, [6][7][8][9][10][11][12] because palladium(II) has a similar coordination mode and chemical properties to platinum(II).12) As the result, several novel palladium(II) complexes having antitumor citotoxic activities against MCF-7, TK-10 and UACC-62 human tumor cell lines, 13) and P388 lymphocytic leukemia cells have been found. [14][15][16][17] In these complexes, the ternary palladium(II) complexes with a heterocyclic ligand and L-glycine one, [Pd(Gly)(X)] (where X is a heterocyclic ligand; 2,2Ј-bipyridylamine(bpa), 15) 1,10-phenanthroline (phen) 16) and 2,2Ј-bipyridine(bpy) 17) ) have the antitumor activity against P388 lymphocytic leukemia cells. At the present time, the structures of these complexes are not yet clear, although they are important for clarifying the mechanism of their antitumor activity. By these circumstances, in this study, our aim was to determine the structures of three ternary Pd(II) complexes, [Pd(Gly)(bpy)], and evaluate the interaction with DNA, which is one of targets in the chemotherapy of tumor. 18) ExperimentalMaterials Analytical grade of 2,2Ј-bipyridine (bpy), 1,10-phenanthroline (phen), and 2,2Ј-bipyridylamine (bpa), L-glycine Methods The X-ray measurements were performed on a Rigaku R-AXIS RAPID diffractometer with a graphite monochromatized MoKa radiation (lϭ0.71069 Å) using the w scan mode at 123.1 K.Fluorescence measurements were performed with a Hitachi 850 spectrofluorometer. UV measurements were made on a Shimazu Pharma Spec UV-1700 Spectrophotometer and CD measurements on a JASCO J-710 CD spectrophotometer. The agarose gel electrophoresis was performed using a COSMO BIO Mupid-2. Elemental analysis was done by using a YANACO CHN Coder MT-3.Preparation of the Complexes The complex 1, 2 and 3 were prepared according to the analogous method described previously. 15,19) 0.76 mmol of bpy, phen or bpa were mixed with 0.76 mmol of PdCl 2 · 2NaCl · 3H 2 O in 5 ml of 80% (v/v) methanol-water solution for about 5 min at room temperature. The precipitates appeared after adding palladium salt. Each precipitate was dried under a vacuum and assumed as [Pd(bpy)Cl 2 ], [Pd(phen)Cl 2 ] and [Pd(bpa)Cl 2 ]. Then, 0.015 mmol of the precipitate was reacted with equal moles of Gly and NaHCO 3 in 5 ml of water solution for about 1 h at 333-343 K, until the volume of the reaction mixture was concentrated to ca. 1 ml. The concentrated solution was allowed to stand at room temperature for slow evaporation. Two weeks later, the light yellow needle crystals of the complex 1 and 3 suitable for X-ray diffraction studies were obtained from the mother liquid, and three months later the brown needle crystal of the complex 2 was obt...

Interaction of palladium(II) coordination compounds with calf thymus DNA and their antibacterial activity

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New palladium(ii) and platinum(ii) 5,5-diethylbarbiturate complexes with 2-phenylpyridine, 2,2′-bipyridine and 2,2′-dipyridylamine: synthesis, structures, DNA binding, molecular docking, cellular uptake, antioxidant activity and cytotoxicity

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Antiproliferative effect and genotoxicity of novel synthesized palladium complexes with organoarsenic ligands

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