Publications by authors named "Alexandra Karaliota"

The reaction of sodium orthovanadate with carnitine hydrochloride molecule results in the precipitation of decavanadate compound of carnitine whereas the reaction of metallic molybdenum with hydrogen peroxide and carnitine results in the peroxo-molybdenum complex of carnitine. The decavanadate compound as well as the molybdenum complex of carnitine have been characterized by means of elemental analysis, IR, electronic spectra, (1)H NMR, 2D-COSY-NMR (=correlation spectroscopy) and thermo-gravimetric analysis (TGA). In addition decavanadate compound of carnitine was fully characterized by X-ray crystallography.

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Five metal complexes of the third-generation quinolone antimicrobial agent sparfloxacin with Fe(3+), VO(2+), Mn(2+), Ni(2+) and UO(2)(2+) have been prepared and characterized with physicochemical and spectroscopic techniques. In these complexes, sparfloxacin acts as a bidentate deprotonated ligand bound to the metal through the ketone oxygen and a carboxylate oxygen. The complexes are six-coordinate with distorted octahedral geometry.

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Two new mononuclear peroxo complexes of tungsten of the formula (gu)(2)[WO(2)(O(2))(2)] (1) and (gu)[WO(O(2))(2)(quin-2-c)] (2a) (where gu(+)=guanidinium ion, CN(3)H(6)(+) and quin-2-c=quinoline-2-carboxylate ion) have been synthesized and characterized by elemental analysis, infrared, Raman, UV-visible and (1)H NMR spectroscopies. The crystal structure of (gu)[WO(O(2))(2)(quin-2-c)].H(2)O (2b) determined by X-ray diffraction indicates that the side-on peroxo groups and the bidentate quinaldate ligand bind the W(VI) centre leading to an hepta coordination mode.

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The neutral mononuclear cobalt(II) complex with sparfloxacin has been prepared and characterized with physicochemical, spectroscopic and electrochemical techniques, and molecular mechanics calculations. The interaction of the complex with calf-thymus DNA has been investigated with UV spectroscopy, cyclic voltammetry, and competitive studies with ethidium bromide. The antimicrobial activity of the complex has been tested against three microorganisms.

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We studied the antitumor properties of the dinuclear copper(II) complex of l-carnitine [Cu 2( l-carnitine) 2Cl 2(H 2O) 2]Cl 2, as well as those of l-carnitine and copper chloride dihydrate, in human leukemic cells. The complex was synthesized and characterized using EPR, (1)H NMR, (13)C NMR, IR, and UV-vis analyses. Its cytotoxic effect on the human leukemia cell lines HL-60 and K562 was studied by assessing the metabolic activity of cells (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT method), the structural integrity of cell membrane using Trypan blue assay, and the proliferation capacity of cells studying growth curves.

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Three novel neutral mononuclear copper(II) complexes of the third-generation quinolone antibacterial drug sparfloxacin in the presence of a nitrogen donor heterocyclic ligand 2,2'-bipyridine, 1,10-phenanthroline or 2,2'-dipyridylamine have been prepared and characterized physicochemically and spectroscopically. The resultant complexes are of the type Cu(sparfloxacinato)(N-donor)Cl. Copper(II) is pentacoordinate having a distorted square pyramidal geometry.

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We have synthesized and characterized a novel copper(II) complex of the fluoroquinolone antibacterial drug N-propyl-norfloxacin (Hpr-norf) in the presence of 1,10-phenanthroline (Phen) and studied its biological properties as antitumor antibiotic and antimicrobial agent. Human acute myeloid leukemia cell line HL-60, MTT assay, and Trypan blue assay were used to test the antileukemic, the cell viability, and the structural integrity of the cell membrane and cell proliferation properties of (chloro)(Phen)( N-propyl-norfloxacinato)copper(II) (complex 1), respectively. We found that the proliferation rate and viability of HL-60 cells decreased after treatment with complex 1, leading to cell death through apoptosis in a time-dependent manner.

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We synthesized and studied the antitumor properties of the novel complex compound 2,5-dihydroxybenzoate molybdenum(VI) with tetraphenylphosphonium as counterion, which also acts as cancer cell growth inhibitor. A novel complex compound, the 2,5-dihydroxybenzoate molybdenum(VI) complex, (PPh4)2[Mo3O6(mu-O)2(2,5-DHBA)2] was synthesized. 1H NMR, 13C NMR, IR, and UV-Vis analyses were used for its molecular characterization.

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Nine new metal complexes of the quinolone antibacterial agent N-propyl-norfloxacin, pr-norfloxacin, with VO(2+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Zn(2+), MoO(2)(2+), Cd(2+) and UO(2)(2+) have been prepared and characterized with physicochemical and spectroscopic techniques while molecular mechanics calculations for Fe(3+), VO(2+) and MoO(2)(2+) complexes have been performed. In all complexes, pr-norfloxacin acts as a bidentate deprotonated ligand bound to the metal through the pyridone and one carboxylate oxygen atoms. All complexes are six-coordinate with slightly distorted octahedral geometry.

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The neutral mononuclear vanadyl complex with the quinolone antibacterial drug enrofloxacin has been prepared and characterized with physicochemical and spectroscopic techniques and molecular mechanics calculations. The interaction of the complex with calf-thymus DNA has also been investigated and the antimicrobial activity has been evaluated against three different microorganisms.

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The neutral mononuclear copper complex with the quinolone antibacterial drug N-propyl-protected norfloxacin, Hpr-norfloxacin, in the presence of the nitrogen donor heterocyclic ligand 2,2'-bipyridine has been prepared and characterized. The crystal structure of (chloro)(2,2'-bipyridine)(pr-norfloxacinato)copper(II), 1, has been determined and refined with X-ray crystallography. X-band electron paramagnetic resonance (=EPR) spectroscopy at liquid helium temperatures from powdered samples indicates the presence of dimeric units in consistency with the crystal structure.

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The mononuclear copper complexes with the quinolone antibacterial drug enrofloxacin (=Herx) in the presence or not of a nitrogen donor heterocyclic ligand 1,10-phenanthroline (=phen) and 2,2'-bipyridine (=bipy) have been prepared and characterized. Interaction of copper(II) with deprotonated enrofloxacin leads to the formation of the neutral complex Cu(erx)2(H2O), 1, while the presence of phen or bipy leads to the formation of a neutral or a cationic mononuclear complex, respectively. The crystal structures of (chloro)(1,10-phenanthroline)(enrofloxacinato)copper(II), 2, and (aqua)(2,2'-bipyridine)(enrofloxacinato)copper(II) chloride, 3, have been determined with X-ray crystallography.

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The neutral mononuclear copper(II) complex with the quinolone antibacterial drug sparfloxacin has been prepared and characterized with IR, UV-vis, and EPR spectroscopies and X-ray crystallography. The interaction of the complex with calf-thymus DNA has also been investigated and the antimicrobial activity has been evaluated against three different microorganisms.

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