Binary orotic acid metal complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), and two mixed metals complexes of (Co(II), Ni(II)) and (Ni(II), Cu(II)) were synthesized and characterized by elemental an...Binary orotic acid metal complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), and two mixed metals complexes of (Co(II), Ni(II)) and (Ni(II), Cu(II)) were synthesized and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility, and ESR spectra. The Analysis proved that the ligand has different coordination modes and the complexes were of octahedral, tetrahedral, and trigonal bipyramidal geometries. Molecular modeling techniques and quantum chemical methods have been performed for orotic acid to calculate charges, bond lengths, bond angles, dihedral angles, electronegativity (χ), chemical potential (μ), global hardness (η), softness (σ) and the electrophilicity index (ω). The thermal decomposition of the complexes was monitored by TGA, DTA, and DSC techniques under the N2 atmosphere. The thermal decomposition mechanisms of the complexes were suggested. The biological activity of orotic acid and some of the complexes are tested against antibacterial and antifungal organisms.展开更多
Tylosin is a well-established antibiotic that has been widely employed in human and veterinary medicines. It can act as a potential ligand binding metal ions due to various donor atoms in the structure. Our study on t...Tylosin is a well-established antibiotic that has been widely employed in human and veterinary medicines. It can act as a potential ligand binding metal ions due to various donor atoms in the structure. Our study on the complexation of various metal ions with tylosin ligand revealed that they preferably coordinate with mycaminose fragment to establish Novel trends complexes. Tylosin ligand (TYS) behaves as bidentate for complexation with different metal ions such as Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II). Various essential metal complexes of tylosin were synthesized and characterized by techniques such as UV, IR, Elemental analysis, magnetic susceptibility and ESR spectra of Cu(II) complex. These techniques are used to know their geometries and mode of bonding, with stoichiometry, 2:2 (M:L). Thermal analysis (TGA and DTA) of ligands and their metal complexes were carried out to distinguish between the coordinate and hydrate solvents and to estimate the stability ranges, peak temperatures. The thermodynamic parameters, such as activation energy (ΔE<sup>*</sup>), the enthalpy of activation (ΔH<sup>*</sup>), entropy of activation (ΔS<sup>*</sup>) and Gibbs free energy (ΔG<sup>*</sup>) are calculated and discussed. Some tylosin complexes show higher activity than tylosin for some bacterial and fungal strains. Low concentration value of minimum inhibitory concentration (MIC) results is 15.625 μg/ml for both complexes [Zn<sub>2</sub>(TYS)<sub>2</sub>Cl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]·25H<sub>2</sub>O and [Cu<sub>2</sub>(TYS)<sub>2</sub>Cl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]·25H<sub>2</sub>O with B. cereus genus maybe a valuable data used to produce novel therapeutic agent. This study constitutes several essential aspects for future research on tylosin metal complexes as antibacterial assessment and as potential medicinal agents.展开更多
文摘Binary orotic acid metal complexes of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), and two mixed metals complexes of (Co(II), Ni(II)) and (Ni(II), Cu(II)) were synthesized and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility, and ESR spectra. The Analysis proved that the ligand has different coordination modes and the complexes were of octahedral, tetrahedral, and trigonal bipyramidal geometries. Molecular modeling techniques and quantum chemical methods have been performed for orotic acid to calculate charges, bond lengths, bond angles, dihedral angles, electronegativity (χ), chemical potential (μ), global hardness (η), softness (σ) and the electrophilicity index (ω). The thermal decomposition of the complexes was monitored by TGA, DTA, and DSC techniques under the N2 atmosphere. The thermal decomposition mechanisms of the complexes were suggested. The biological activity of orotic acid and some of the complexes are tested against antibacterial and antifungal organisms.
文摘Tylosin is a well-established antibiotic that has been widely employed in human and veterinary medicines. It can act as a potential ligand binding metal ions due to various donor atoms in the structure. Our study on the complexation of various metal ions with tylosin ligand revealed that they preferably coordinate with mycaminose fragment to establish Novel trends complexes. Tylosin ligand (TYS) behaves as bidentate for complexation with different metal ions such as Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II). Various essential metal complexes of tylosin were synthesized and characterized by techniques such as UV, IR, Elemental analysis, magnetic susceptibility and ESR spectra of Cu(II) complex. These techniques are used to know their geometries and mode of bonding, with stoichiometry, 2:2 (M:L). Thermal analysis (TGA and DTA) of ligands and their metal complexes were carried out to distinguish between the coordinate and hydrate solvents and to estimate the stability ranges, peak temperatures. The thermodynamic parameters, such as activation energy (ΔE<sup>*</sup>), the enthalpy of activation (ΔH<sup>*</sup>), entropy of activation (ΔS<sup>*</sup>) and Gibbs free energy (ΔG<sup>*</sup>) are calculated and discussed. Some tylosin complexes show higher activity than tylosin for some bacterial and fungal strains. Low concentration value of minimum inhibitory concentration (MIC) results is 15.625 μg/ml for both complexes [Zn<sub>2</sub>(TYS)<sub>2</sub>Cl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]·25H<sub>2</sub>O and [Cu<sub>2</sub>(TYS)<sub>2</sub>Cl<sub>2</sub>(H<sub>2</sub>O)<sub>4</sub>]·25H<sub>2</sub>O with B. cereus genus maybe a valuable data used to produce novel therapeutic agent. This study constitutes several essential aspects for future research on tylosin metal complexes as antibacterial assessment and as potential medicinal agents.
