Maher M.I. El-Dessouky

Ligational behaviour of lomefloxacin drug towards Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Th(IV) and UO2(VI) ions: Synthesis, structural characterization and biological activity studies

Nine new mononuclear Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Th(IV) and UO(2)(VI) complexes of lomefloxacin drug were synthesized. The structures of these complexes were elucidated by elemental analyses, IR, XRD, UV-vis, (1)H NMR as well as conductivity and magnetic susceptibility measurements and thermal analyses. The dissociation constants of lomefloxacin and stability constants of its binary complexes have been determined spectrophotometrically in aqueous solution at 25±1°C and at 0.1 M KNO(3) ionic strength. The discussion of the outcome data of the prepared complexes indicate that the lomefloxacin ligand behaves as a neutral bidentate ligand through OO coordination sites and coordinated to the metal ions via the carbonyl oxygen and protonated carboxylic oxygen with 1:1 (metal:ligand) stoichiometry for all complexes. The molar conductance measurements proved that the complexes are electrolytes. The powder XRD study reflects the crystalline nature for the investigated ligand and its complexes except Mn(II), Zn(II) and UO(2)(II). The geometrical structures of these complexes are found to be octahedral. The thermal behaviour of these chelates is studied where the hydrated complexes lose water molecules of hydration in the first steps followed by decomposition of the anions, coordinated water and ligand molecules in the subsequent steps. The activation thermodynamic parameters are calculated using Coats-Redfern and Horowitz-Metzger methods. A comparative study of the inhibition zones of the ligand and its metal complexes indicates that metal complexes exhibit higher antibacterial effect against one or more bacterial species than the free LFX ligand. The antifungal and anticancer activities were also tested. The antifungal effect of almost metal complexes is higher than the free ligand. LFX, [Co(LFX)(H(2)O)(4)]·Cl(2) and [Zn(LFX)(H(2)O)(4)]·Cl(2) were found to be very active with IC50 values 14, 11.2 and 43.1, respectively. While, other complexes had been found to be inactive at lower concentration than 100 μg/ml.

Coordination modes of bidentate lornoxicam drug with some transition metal ions. Synthesis, characterization and in vitro antimicrobial and antibreastic cancer activity studies.

The NSAID lornoxicam (LOR) drug was used for complex formation reactions with different metal salts like Cr(III), Mn(II), Fe(III) and Ni(II) chlorides and Fe(II), Co(II), Cu(II) and Zn(II) borates. Mononuclear complexes of these metals are obtained that coordinated to NO sites of LOR ligand molecule. The nature of bonding and the stereochemistry of the complexes have been deduced from elemental analyses, IR, UV-Vis, (1)H NMR, mass, electronic spectra, magnetic susceptibility and ESR spectral studies, conductivity measurements, thermogravimetric analyses (TG-DTG) and further confirmed by X-ray powder diffraction. The activation thermodynamic parameters are calculated using Coats-Redfern and Horowitz-Metzger methods. The data show that the complexes have composition of ML2 type except for Fe(II) where the type is [ML3]. The electronic absorption spectral data of the complexes suggest an octahedral geometry around the central metal ion for all the complexes. The antimicrobial data reveals that LOR ligand in solution show inhibition capacity less or sometimes more than the corresponding complexes against all the species under study. In order to establish their future potential in biomedical applications, anticancer evaluation studies against standard breast cancer cell lines (MCF7) was performed using different concentrations. The obtained results indicate high inhibition activity for Cr(III), Fe(II) and Cu(II) complexes against breast cancer cell line (MCF7) and recommends them for testing as antitumor agents.

Crosslinked grafted PVC obtained by direct radiation grafting

Abstract Direct radition-induced grafting of 4-vinylpyridine onto both pure and plasticized poly(vinyl chloride) has been studied. The effect of grafting conditions such as solvent, monomer concentration, irradiation dose, and inhibitor concentration on the grafting yield was investigated. The grafting process was enhanced by using distilled water as diluent and higher degrees of grafting were obtained as compared with other solvents used (benzene, methanol, and a mixture of methanol and water). The homopolymerization of 4-vinylpyridine was reduced to a minimum using ammonium ferrous sulfate and the suitable optimum concentration of the inhibitor was found to be 0.25 wt %. It was observed that the degrees of grafting onto plasticized PVC were higher than those onto pure one, at constant grafting conditions. The diffusibility of the monomer solution through the trunk polymers enhanced at higher monomer concentrations. The higher the monomer concentration the higher the degrees of grafting obtained. The dependence of the grafting rate on monomer concentration was found to be 0.15 and 0.4 order for the grafting onto pure and plasticized PVC films, respectively. The degree of grafting, at the higher irradiation doses, deviated from linearity and it tends to level off due to the recombination of some of the free radicals without initiating graft polymerization. Gel determination in the grafted films was investigated. The gel content in both grafted extracted pure and plasticized PVC films increased with the degree of grafting to reach a certain limiting values.

Anionic membranes obtained by radiation grafting of 4-vinylpyridine onto poly(vinyl chloride)

Abstract Some properties of the membranes obtained by radiation grafting of 4-vinylpyridine onto poly(vinyl chloride), PVC, have been studied. Quaternization of nitrogen atoms in the grafted films was completely achieved by using Mel and HCL as quaternizing agents. The grafted quaternized pure and plasticized PVC films possess much higher water uptake percent than those grafted unquaternized ones. The quaternized grafted films also show higher electrical conductivity than grafted unquaternized ones. Furthermore, the electrical conductivity of Mel- and HCL-quaternized plasticized PVC films was 100 times that those of quaternized pure, at a given degree of grafting. The tensile strength and elongation percent for the trunk films were measured at various irradiation doses in N 2 atmosphere and in air. The mechanical properties of the wet grafted films were also investigated for films having various degrees of grafting. The good swelling behaviour of the grafted quaternized PVC films and the good mechanical strength of the grafted films may make them acceptable for handling and practical use as anion-exchange membranes.

Some investigations on the post radiation grafting of acrylamide onto polyethylene films

Abstract A study has been made on the post radiation grafting of aqueous acrylamide onto low density polyethylene film. It was found that the addition of 0.05 wt % Mohrs salt reduced effectively the homopolymerization of acrylamide and the grafting process was successfully achieved. The dependence of the grafting rate on the preirradiation dose and monomer concentration was found to be of 1.43 and 1.4 order, respectively. The overall activation energy for the graft polymerization was found to be 13.5 and 1.95 Kcal/mol below and above 45°C, respectively. Some properties of the graft copolymer such as swelling behaviour, electrical conductivity, and reverse osmosis desalination of saline water (water flux and salt rejection), were also investigated and the possibility of its uses in the practical applications was discussed.

Electrical conductivity of anionic graft copolymers obtained by radiation grafting of 4-vinylpyridine onto poly(vinyl chloride)

Abstract The electrical conductivity of the graft copolymers, obtained by direct radiation grafting of 4-vinylpyridine onto pure and plasticized poly(vinyl chloride) PVC films was investigated under various temperatures and applied potentials. The electrical conductivity of such graft copolymers increased as the temperature was elevated, for a given applied potential and degree of grafting. The degree of grafting, the additives in PVC, and the quaternizing agent have an influence on the electrical behaviour of the grafted films. The main feature of the activation energy of the graft copolymers was its very low values and two different activation energies were found for each copolymer based on the applied potential. The values of the activation energy for MeI-quaternized plasticized PVC film were almost twice those for the MeI-quaternized pure one. When using HCl as quaternizing agent, however, values of the activation energy for both grafted pure and plasticized PVC films were almost the same at a given applied potential.

Anion-exchange separation of thorium and protactinium from uranium matrix

SummaryThe distribution behaviour of Th4+, Pa5+, and UO22+ ions between the anion-exchanger Amberlite IRA-400 and acetic acid-hydrochloric acid mixtures, has been investigated. It was found that the general behaviour of Th4+ ions is similar to that of UO22+ ions though the latter are much more highly adsorbed by the resin than Th4+. Protactinium exhibited a different behaviour from both Th4+ and UO22+ ions. The separation factors were calculated, and a Chromatographic procedure for sequential isolation of each element was developed.ZusammenfassungDas Verteilungsverhalten von Th4+, Pa5+ und UO22+ zwischen dem Anionenaustauscher Amberlit IRA-400 und Gemischen aus Essigsäure und Salzsäure wurde untersucht. Das allgemeine Verhalten von Th4+ ist ähnlich dem von Uranylionen, wenngleich letztere von dem Harz viel stärker adsorbiert werden als Th4+. Protactinium zeigt ein abweichendes Verhalten im Vergleich zu Th4+ und UO22+. Die Trennfaktoren wurden berechnet und ein chromatographisches Verfahren zur Isolierung der angeführten Ionen entwickelt.