L. Perelló

Interactions of metal ions with two quinolone antimicrobial agents (cinoxacin and ciprofloxacin): Spectroscopic and X-ray structural characterization. Antibacterial studies

Several novel metal-quinolone compounds have been synthesized and characterized by analytical, spectroscopic and X-ray diffraction methods. The crystal structure of the four compounds, Na(2)[(Cd(Cx)3)(Cd(Cx)3(H2O))].12H2O, [Co(Cp)2(H2O)2].9H2O, [Zn(Cp)2(H2O)2].8H2O and [Cd(HCp)2(Cl)2].4H2O, is presented and discussed: HCx=1-ethyl-1,4-dihydro-4-oxo(1,3)-dioxolo(4,5-g)cinnoline-3-carboxylic acid and HCp=1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid. In all these compounds the quinolone acts as a bidentate chelate ligand that binds through one carboxylate oxygen atom and the exocyclic carbonyl oxygen atom. Complexes of ciprofloxacin were screened for their activity against several bacteria, showing activity similar to that of the ligand. In addition, the number of bacteria killed after 3 h of incubation with the ligand, [Co(Cp)2(H2O)2].9H2O, Ni(Cp)2.10H2O and Cu(Cp)2.6H2O, was determined against S. aureus ATCC25923. There is a direct relationship between the growth rate and the lethal rate. Against growing bacteria, the ligand is the most bactericidal and Cu(Cp)2.6H2O is the less bactericidal. On the contrary, against non-dividing bacteria, the complexes were more bactericidal than the ligand, with Cu(Cp)(2).6H(2)O the most bactericidal compound.

Cinoxacin complexes with divalent metal ions. Spectroscopic characterization. Crystal structure of a new dinuclear Cd(II) complex having two chelate-bridging carboxylate groups. Antibacterial studies

Several cinoxacin (HCx) complexes with divalent metal ions have been prepared and characterized by spectroscopic techniques. The crystal structure of [Cd2(Cx)4(H2O)2].10H2O has been determined by X-ray diffraction. The complex is triclinic, space group P1 with unit-cell dimensions: a = 10.412(2), b = 11.119(2), c = 13.143(6)A, chi== 76.78(4) degrees, beta = 74.59(3) degrees, gamma = 77.12(3) degrees, V = 1406.0(8) A3. In this complex each cadmium atom is heptacoordinated: the metal environment is formed by two Oketo and two Ocarbox atoms from two different cinoxacinate monoanions, two carboxylate oxygen atoms from a third cinoxacinate ligand and by one water oxygen atom on the seventh position. Two of the cinoxacinate ions act as tridentate chelate and bridging ligands and the other one as a bidentate chelate ligand. In the bridging monoanions the carboxylate group is behaving as a chelate ligand. All the complexes were screened for their activity against several bacteria, showing activity similar to that of cinoxacin. Additionally, the number of bacteria killed after 3 h of incubation with cinoxacin, [Cu(Cx)2].2H2O and [Co(Cx)3]Na.10H2O complexes was determined against E. coli ATCC 25922; the copper compound presents paradoxical effect which has been described and related to the mechanism of action of quinolones.

Synthesis, characterization, and crystal structure of [Cu(cinoxacinate)2] · 2H2O complex: A square-planar CuO4 chromophore. Antibacterial studies

The structural and spectroscopic properties of a new copper (II) complex of cinoxacin (HCx) have been investigated. The complex [Cu(Cx)2].2H2O crystallizes in the monoclinic system, space group P2(1)/c. The cell dimensions are: a = 7.998(2), b = 7.622(1), c = 18.955(6) A, beta = 94.38(2) degree, V = 1154.6(6) A3, Z = 2. The structure was refined to R = 0.051. The crystal is composed of [Cu(Cx)2] units and uncoordinated water molecules. The Cu(II) ion, at a center of symmetry, is coordinated to two cinoxacinate (Cx) ligands related by the inversion center. Each cinoxacinate acts as bidentate ligand bonded to the cation through its carboxylate oxygen atom and through its exocyclic carbonyl oxygen atom, resulting in a CuO4 chromophore in a crystallographically planar configuration. The complex was screened for its activity against several bacteria, showing the same antimicrobial activity as the corresponding ligand.

Potentiometric and spectroscopic studies of transition-metal ions complexes with a quinolone derivative (cinoxacin). Crystal structures of new Cu(II) and Ni(II) cinoxacin complexes

Abstract The interaction of cobalt(II), nickel(II), copper(II), and zinc(II) with Cinoxacin (HCx = 1-ethyl-1,4-dihydro-4-oxo(1,3)dioxolo(4,5-g)cinnoline-3-carboxylic acid), a 4-quinolone derivative, has been studied at metal/ligand ratios of 1:1-1:3 by means of pH-metric, spectrophotometric, and ESR methods. The formation constants have been determined and the stereochemistry for the metal ions in the species present in aqueous solutions (at 37 ± 0.1°C and I = 0.1 mol dm −3 NaCl) is discussed. In all the studied systems, complexes with different stoichiometric ratios, in which cinoxacin acts both as neutral and deprotonated ligand, are formed. The anomalous sequence of the stepwise stability constants observed for cobalt(II) and nickel(II) systems suggests changes in stereochemistry when CoCx 2 and NiCx 2 are formed. For zinc(II) this change has to be still more pronounced since a [ZnCx] + species has not been detected. For the Cu(II) system the sequence in the stepwise stability constants indicates the preferential formation of the [CuCx] + monocomplex. The crystal and molecular structure of new Cu(II) and Ni(II) complexes of cinoxacin have been investigated. The metal ion in [Cu(Cx) 2 H 2 O]·3H 2 O is five-coordinated and the complex crystallizes in the triclinic P 1 space group with a = 10.620(1), b = 11.358(1), c = 12.440(2) A , α = 78.25(1), β = 80.24(1), γ = 63.34(1)°, and Z = 2 . The complex [Ni(Cx) 2 -(DMSO) 2 ]·4H 2 O contains six-coordinated Ni(II) and crystallizes in the triclinic P 1 space group with a = 8.866(3), b = 9.141(1), c = 11.580(1) A , α = 69.301(9), β = 82.17(2), γ = 75.86(2)°, and Z = 1 .

Coordination behavior of cinoxacine: Synthesis and crystal structure of tris (cinoxacinate) cobaltate(II) of sodium hexahydrate (HCx = 1-ethyl-4(1H) -oxo-(1,3) dioxolo-(4,5g) cinnoline-3-carboxylic acid)

The synthesis, crystal, and molecular structure of Co(Cx)3Na6H2O are reported. The Cobalt(II) compound crystallizes in the trigonal system, space group R 3 with Z = 6, in a cell of dimensions a= 18.688(7) (A), c= 20.142(6) A. Least-squares refinement of 1331 reflections [I≥3σ(I)] gave a final R = 0.088 for all observed reflections. The structure consists of anionic monomeric units of (Co(Cx)3−) and sodium cations. Three Cinoxacinate ions are chelated through Oceto and Ocarbox atoms. The Co(II) ion positioned on the third axis is bonded to six oxygen atoms in a slightly distorted octahedral environment.

Synthesis and characterization of Cd(II) complexes of cinoxacin. Crystal structure of a dicadmium complex containing two monoatomic-bridging carboxylate oxygen atoms

Abstract The reaction of CdCl 2 · 1 2 H 2 O with cinoxacin in DMSO solution affords the [Cd 2 (Cx) 4 (DMSO) 2 ]·2H 2 O dimeric complex ( I ) which has been characterized by single crystal X-ray diffraction; complex II (Cd(Cx) 2 ·H 2 O) was prepared by dissolving I in a minimum amount of water. Compound I is triclinic, space group P 1 with unit cell dimensions: a =8.960(1), b =12.084(5), c =13.696(6) A, α=73.96(4), β=84.69(4), γ=80.93(49)°, V =1405.5(9) A 3 . Each dimer contains cadmium atoms bridged by two carboxylate oxygen atoms from two cinoxacinate (Cx) ligands generating planar Cd 2 O 2 rings. The metal environment is formed by two O carbox and O ceto atoms from the cinoxacinate monoanions, one oxygen atom of the DMSO molecule and a carboxylate oxygen atom which acts as a bridge. One of the coordinated cinoxacinate molecules acts as a bidentate chelate and bridging ligand and the other one as a bidentate chelate ligand. The solid-state IR and 13 C NMR spectra of both compounds are discussed in detail with regard to the crystal structure of complex I .

Synthesis and spectroscopy studies of copper(II) nitrate of sulfacetamide drug. Crystal structure of [Cu(sulfacetamide)2(NO3)2]. Antibacterial studies

The structural spectroscopic, and thermal properties of a complex of sulfacetamide (Hsacm) with Cu(II) have been investigated. The complex [Cu(Hsacm)2(NO3)2] crystallizes in the monoclinic system, space group P2(1)/n. The cell dimensions are a = 7.696(7) A, b = 8.017(7) A, c = 19.230(10), beta = 110.80(1) degree, V = 1109(1) A3, Z = 2, and Dx = 1.84 g/cm3. The structure was refined to R = 0.0776. Cu(Hsacm)2(NO3)2 molecules form a long polymeric chain extended along the b-axis. The copper(II) coordinated geometry is tetragonally distorted octahedral with two amino nitrogens from Hsacm and two oxygens from nitrato anions in the basal plane and two acetamido oxygens from neighbor Hsacm molecules in the apical position. Each sulfacetamide, acting as a bidentate ligand, links two Cu(II) ions as a bridge through the Namino and the Oacetamido atoms. The complex proved to possess higher bacteriostatic activity than the corresponding ligand.

Development of Novel DNA Cleavage Systems Based on Copper Complexes. Synthesis and Characterisation of Cu(II) Complexes of Hydroxyflavones

Copper(II) complexes of several hydroxyflavones were prepared and characterised through their physico-chemical properties. The nuclease activity of three synthesised complexes is reported. These copper(II) complexes present more nuclease activity than the ligands and the copper(II) ion.

Thermal studies on cinoxacin complexes: Part II. Thermal behaviour of some metal complexes of cinoxacin

Abstract The thermal behaviour of complexes of cinoxacin with Co(II), Zn(II) and Cd(II) was studied using thermogravimetry (TG) and differential scanning calorimetry (DSC). The complexes decompose in two steps: dehydration and pyrolitic decomposition. Dehydration enthalpies have been calculated from the DSC curves.

Ternary complexes of Cu(II) ion with cimetidine and L-alanine

(Cu(CM)A)B(C6H5)4 and Cu(CM)A(OH) X H2O (CM = cimetidine and HA = L-alanine) were prepared and characterized by elemental analysis, TG-DTA, IR, and electronic spectral data and magnetic susceptibility measurements. The EPR spectrum of (Cu(CM)A)B(C6H5)4 shows a distorted octahedral environment for the Cu(II) ion.