Pharmaceutical Chemistry Department, Faculty of Pharmacy, Misr International University, Cairo, Egypt.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Nov;82(1):8-19. doi: 10.1016/j.saa.2011.05.089. Epub 2011 Jun 1.
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.
合成了 9 种新的单核 Cr(III)、Mn(II)、Fe(III)、Co(II)、Ni(II)、Cu(II)、Zn(II)、Th(IV) 和 UO(2)(VI)与洛美沙星药物的配合物。通过元素分析、IR、XRD、UV-vis、(1)H NMR 以及电导率和磁化率测量和热分析，阐明了这些配合物的结构。在 25±1°C 和 0.1 M KNO(3)离子强度下，通过分光光度法测定了洛美沙星在水溶液中的离解常数和二元配合物的稳定常数。对所制备配合物的结果数据的讨论表明，洛美沙星配体通过 OO 配位体作为中性双齿配体起作用，并通过羰基氧和质子化羧酸氧与金属离子以 1:1（金属：配体）的化学计量比配位。摩尔电导率测量证明了这些配合物是电解质。粉末 XRD 研究反映了所研究的配体及其配合物的结晶性质，除了 Mn(II)、Zn(II)和 UO(2)(II)。这些配合物的几何结构被发现为八面体。研究了这些螯合物的热行为，其中水合配合物在最初步骤中失去水合水分子，随后阴离子、配位水和配体分子分解。使用 Coats-Redfern 和 Horowitz-Metzger 方法计算了激活热力学参数。对配体及其金属配合物的抑菌圈进行了比较研究，结果表明金属配合物对一种或多种细菌的抑菌效果高于游离 LFX 配体。还测试了抗真菌和抗癌活性。几乎所有金属配合物的抗真菌作用都高于游离配体。发现 LFX、[Co(LFX)(H(2)O)(4)]·Cl(2)和[Zn(LFX)(H(2)O)(4)]·Cl(2)的 IC50 值分别为 14、11.2 和 43.1，具有很高的抗真菌活性。而其他配合物在低于 100μg/ml 的浓度下则没有活性。
