ABSTRACT
In the search for new compounds with antitumor activity, coordination complexes with different metals are being studied by our group. This work presents the synthesis and characterization of six copper complexes with general stoichiometry [Cu(L-dipeptide)(phen)]·nH2O (were phen=1,10-phenanthroline) and their cytotoxic activities against tumor cell lines. To characterize these systems, analytical and spectroscopic studies were performed in solid state (by UV-visible, IR, X-ray diffraction) including the crystal structure of four new complexes (of the six complexes studied): [Cu(Ala-Phe)(phen)]·4H2O, [Cu(Phe-Ala)(phen)]·4H2O, [Cu(Phe-Val)(phen)]·4.5H2O and [Cu(Phe-Phe)(phen)]·3H2O. In all of them, the copper ion is situated in a distorted squared pyramidal environment. The phen ligand is perpendicular to the dipeptide, therefore exposed and potentially available for interaction with biological molecules. In addition, for all the studied complexes, structural information in solution using EPR and UV-visible spectroscopies were obtained, showing that the coordination observed in solid state is maintained. The lipophilicity, DNA binding and albumin interaction were also studied. Biological experiments showed that all the complexes induce cell death in the cell lines: HeLa (human cervical adenocarcinoma), MCF-7 (human metastatic breast adenocarcinoma) and A549 (human lung epithelial carcinoma). Among the six complexes, [Cu(Ala-Phe)(phen)] presents the lowest IC50 values. Taken together all these data we hypothesize that [Cu(Ala-Phe)(phen)] may be a good candidate for further studies in vivo.
Subject(s)
Antineoplastic Agents/chemical synthesis , Coordination Complexes/chemical synthesis , Phenanthrolines/chemical synthesis , Albumins/chemistry , Antineoplastic Agents/pharmacology , Coordination Complexes/pharmacology , Copper/chemistry , Crystallography, X-Ray , Dipeptides/chemistry , HeLa Cells , Humans , Inhibitory Concentration 50 , MCF-7 Cells , Models, Molecular , Molecular Conformation , Phenanthrolines/pharmacology , Protein BindingABSTRACT
The infrared (IR), Raman and 57Fe-Mössbauer spectra of SrFe2(P2O7)2, BaFe2(P2O7)2 and PbFe2(P2O7)2 were recorded and discussed on the basis of the structural peculiarities of the compounds.
Subject(s)
Cations/chemistry , Diphosphates/chemistry , Iron Radioisotopes/chemistry , Iron/chemistry , Spectroscopy, Fourier Transform Infrared/methods , Spectroscopy, Mossbauer/methods , Phosphates/chemistry , Spectrophotometry, Infrared , Spectrum Analysis, Raman , Temperature , X-Ray DiffractionABSTRACT
The molecular structure of [Cu(sulfadimet)(2)].SO(CH(3))(2) (sulfadimet=sulfadimethoxine=4-p-aminobenzenesulfonamido-2,6-dimethoxypyrimidine) was determined by single crystal X-ray diffractometry. It crystallizes in the monoclinic space group P2(1)/c with Z=4. The Cu(II) cation is in a distorted CuN(5) square pyramidal coordination, involving four sulfadimethoxine molecules, one of them acting as a bidentate ligand. The infrared spectrum is briefly discussed on the basis of the structural peculiarities of the complex.
Subject(s)
Copper/chemistry , Sulfadimethoxine/chemistry , Crystallography, X-Ray , Models, Molecular , Molecular StructureABSTRACT
Three new copper(II) complexes of stoichiometry [Cu(L-dipeptide)].nH(2)O, containing as ligands the dipeptides L-alanine-L-isoleucine, L-alanine-L-threonine and L-alanine-L-tyrosine were prepared. They were characterized by single crystal X-ray diffractometry, and electronic and infrared spectroscopy. In all cases, the Cu(II) cation has essentially the same elongated square pyramidal coordination, being equatorially cis coordinated by a N(2)O(2) arrangement of ligand atoms and axially by a carbonyl oxygen atom. The compounds show rather similar polymeric structures which resemble those recently reported for the [Cu(ala-val)] and [Cu(ala-phe)] complexes. The electronic and infrared spectra are briefly discussed on the basis of the structural peculiarities of the complexes. Superoxide dismutase (SOD)-like activity was also tested for the compounds.
Subject(s)
Copper/chemistry , Dipeptides/chemistry , Dipeptides/chemical synthesis , Animals , Cattle , Crystallography, X-Ray , Dipeptides/metabolism , Erythrocytes , Models, Molecular , Molecular Conformation , Spectrophotometry, Infrared , Superoxide Dismutase/metabolismABSTRACT
Complexes of the type [Re(III)L6]X3, with L = thiourea, N-methylthiourea, N-ethylthiourea or N,N'-dimethytlthiourea and X = Cl- or PF6-, were prepared as suitable precursors for the synthesis of new rhenium complexes potentially useful in nuclear medicine. The infrared (IR) spectra of these complexes were recorded and analyzed and a general vibrational pattern for Re(III) complexes with thiourea derivatives could be established. Approximate assignments for N-allylthiourea and N-ethylthiourea are also proposed for the first time. The synthesis of the new complex [Re(III)(N-allylthiourea)6](PF6)3 is also reported, and information about its structural characteristics was obtained comparing its IR spectrum with those of the other complexes of the investigated series.