title: Synthesis, X-ray structure and cytotoxic effect of nickel(II) complexes with pyrazole ligands.
abstract: Here we present the synthesis of the new Ni(II) complexes with chelating ligands 1-benzothiazol-2-yl-3,5-dimethyl-1H-pyrazole (a), 5-(2-hydroxyphenyl)-3-methyl-1-(2-pyridylo)-1H-pyrazole-4-carboxylic acid methyl ester (b) and 1-benzothiazol-2-yl-5-(2-hydroxyphenyl)-3-methyl-1H-pyrazole-4-carboxylic acid methyl ester (c). These ligands a-c create solid complexes with Ni(II). The crystal and molecular structures of two complexes were determined by X-ray diffraction method. Thermal stability of two complexes with ligand c by TG/DTG and DSC methods were also shown. Cytotoxic activity of all the complexes against three tumour cell lines and to normal endothelial cells (HUVEC) was also estimated. Complexes with ligand c exhibited relatively high cytotoxic activity towards HL-60 and NALM-6 leukaemia cells and WM-115 melanoma cells. Cytotoxic effectiveness of one of these complexes against melanoma WM-115 cells was two times higher than that of cisplatin. The protonation constant log K=9.63 of ligand b corresponding to the phenol 2-hydroxy group has been determined in 10% (v/v) DMSO/water solution (25°C). The coordination modes (formation of two monomeric species: NiL and NiL(2)) in the complexes with Ni(II) are discussed for b on the basis of the potentiometric and UV/Vis data.
authors: Collegium Medicum in Bydgoszcz, Nicholaus Copernicus University in Torun, Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, 85-094 Bydgoszcz, Poland.
authors: Marta
authors: M
authors: Sobiesiak
authors: Ingo-Peter
authors: IP
authors: Lorenz
authors: Peter
authors: P
authors: Mayer
authors: Magdalena
authors: M
authors: Woźniczka
authors: Aleksander
authors: A
authors: Kufelnicki
authors: Urszula
authors: U
authors: Krajewska
authors: Marek
authors: M
authors: Rozalski
authors: Elzbieta
authors: E
authors: Budzisz
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002614:Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D009369:Neoplasms / Q000188:drug therapy; D009532:Nickel / Q000737:chemistry* / Q000494:pharmacology*; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D002614:Chelating Agents; D056831:Coordination Complexes; D008024:Ligands; D011720:Pyrazoles; C031280:pyrazole; D009532:Nickel