Continuing our search for metal drugs with markedly higher toxicity to cancer cells than to normal cells, we evaluated the effect of 2,2'-bipyridine (bpy) as a co-ligand in the compounds [Cu(μ-O,O'-NO)(L-Arg)(bpy)]NO} (1) and [CuCl(L-Arg)(bpy)]Cl·3HO (2) (L-Arg = L-arginine), on DNA interaction, cytotoxic and antiproliferative activity, compared to the effects induced by other co-ligands i.e. 1,10-phenanthroline (phen) and SCN ions, in similar Cu(II) compounds we have studied previously.
View Article and Find Full Text PDFThe mode of coordination of copper(II) ions with dopamine (DA, L) in the binary, as well as ternary systems with Ado, AMP, ADP, and ATP (L') as second ligands, was studied with the use of experimental-potentiometric and spectroscopic (VIS, EPR, NMR, IR)-methods and computational-molecular modeling and DFT-studies. In the Cu(II)/DA system, depending on the pH value, the active centers of the ligand involved in the coordination with copper(II) ions changed from nitrogen and oxygen atoms (CuH(DA), Cu(DA)), via nitrogen atoms (CuH(DA)), to oxygen atoms at strongly alkaline pH (Cu(DA)). The introduction of L' into this system changed the mode of interaction of dopamine from oxygen atoms to the nitrogen atom in the hydroxocomplexes formed at high pH values.
View Article and Find Full Text PDFl-argininato copper(II) complexes have been intensively investigated in a variety of diseases due to their therapeutic potential. Here we report the results of comprehensive structural studies (ESI-MS, NIR-VIS-UV, EPR) on the complexes arising in aqueous solutions of two ternary copper(II) complexes with molecular formulas from crystal structures, [Cu(l-Arg)(NCS)](NCS)·HO (1) and [Cu(l-Arg)(NCS)] (2) (l-Arg = l-arginine). Reference systems, the ternary Cu(II)/l-Arg/NCS as well as binary Cu(II)/NCS and Cu(II)/l-Arg, were studied in parallel in aqueous solutions by pH-potentiometric titration, EPR and VIS spectroscopy to characterize stability, structures and speciation of the formed species over the broad pH range.
View Article and Find Full Text PDFPotentiometric and NMR spectroscopic studies of the nucleotide (NucP)/polyamine (PA) system (where NucP = CDP, CTP, PA = putrescine or spermidine) revealed the formation of molecular complexes (NucP)(H)(PA) (where H = number of protons; x - from NucP and y - from PA). Their thermodynamic parameters were determined and the modes of their interactions were proposed. The main reaction centers were found to be the protonated amine groups of polyamine (positive centers) and phosphate groups of nucleotide (negative centers).
View Article and Find Full Text PDFThe mode of interaction and thermodynamic stability of complexes formed in binary and ternary Cu(II)/ATP/triamines systems were studied using potentiometric and spectroscopic (NMR, EPR, UV-Vis) methods. It was found that in binary metal-free systems ATP/HPA species are formed (PA: Spd=spermidine or 3,3-tri=1,7-diamino-4-azaheptane) where the phosphate groups from nucleotides are preferred negative centers and protonated amine groups of amines are positive centers of reaction. In the ternary systems Cu/ATP/H(PA) as well as Cu/(ATP)(PA) species are formed.
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