No abstract

A novel series of Zn, Cd and UO complexes of ligands namely 1-[(5-mercapto-1H-1,2,4-triazole-3-ylimino) methyl]naphthalene-2-ol (HL) and [(1H-1,2,4-triazole-3-ylimino) methyl] naphthalene-2-ol (HL) have been prepared and characterized by different analytical and spectral techniques. The stoichiometry, stereochemistry, conductivity measurements and mode of bonding of the complexes have been elucidated. Accurate comparison of the IR spectra of the ligands with their metal chelates proved the involvement of nitrogen atoms of the azomethine group and/or triazole ring in chelation in addition to the deprotonated hydroxyl oxygen. The UV-Vis and molar conductance data supported the octahedral geometry for the metal complexes. TGA technique has been used to study the thermal decomposition way of the metal complexes and the thermo kinetic parameters were estimated. Valuable information is obtained from calculations of molecular parameters using the molecular modeling techniques. The interaction between the metal complexes and CT-DNA has been studied from which the binding constants (k) were calculated. The Schiff bases and their metal chelates have shown potent antimicrobial, antioxidant and antitumor activities. The antitumor activities of the compounds have been tested in vitro against HEPG2 cell line and in silico by the molecular docking analysis with the VEGFR-2 receptor responsible for angiogenesis.

Cu(II), Co(II), Mn(II), Cr(III) and Mn(III) chelates of the ligand obtained by the condensation of 4H-3,5-diamino-1,2,4-triazole and 2-hydroxy-1naphthaldehyde have been isolated and characterized by means of elemental analysis, inductively coupled plasma analysis, mass spectrometry, Fourier transform infrared and UV-visible spectroscopies, magnetic measurements and thermal analysis. The analytical results indicated the formation of the metal complexes in a ligand-to-metal molar ratio of 1:2. The ligand is connected to the metal ion in a tetradentate fashion coordinating to the metal center through the azomethine nitrogens and deprotonated phenolic OH groups.The spectral and magnetic results supported the formation of octahedral geometry around the Cu(II), Mn(III) and Cr(III) centers while Co(II) and Mn(II) centers were confirmed to have tetrahedral geometry. Molecular docking was used to predict the binding between the ligand and the oncogenic protein Hras (121p). The antiproliferative activity of the compounds under study was evaluated in vitro using MTT assay against liver carcinoma (HepG2) and breast cancer (MCF-7) cell lines comparing with cisplatin. The binding mode of selected metal chelates with salmon serum DNA was investigated using the electronic absorption titration method.

A new azo dye ligand (abbreviated as H 3 L) derived from coupling of sulfafurazole diazonium salt with 2,4-dihydroxybenzaldehyde was prepared and characterized applying different spectroscopic and analytical techniques.The novel nanosized trivalent Cr and Fe alongside with divalent Mn, Co, Ni, and Cd complexes with H 3 L have been synthesized for further promising pharmaceutical uses. All complexes were totally characterized by investigating various analytical and spectral tools such as microanalysis, FT-IR, 1 H NMR, UV-Vis, powder XRD, and TEM spectra as well as magnetic moment and molar conductance measurements. Microanalysis, TGA, and conductance studies confirmed the formation of all metal complexes in 1:1 (L: M) molar ratio with covalent mode. The FT-IR and 1 H NMR investigation asserted the chelation of H 3 L to different metal ions through azo nitrogen and phenolic deprotonated hydroxy oxygen in the o-position. UV-Vis, ESR, and magnetic moment studies revealed octahedral geometry around Cr and Fe ions, whereas Mn, Co, Ni, and Cd complexes displayed tetrahedral configurations. XRD patterns and TEM images proved homogeneous distribution over the chelates surfaces and nanometric size of complexes particles. Molecular modeling was used to optimize the complexes' geometric structure showing good harmonity with the experimental results. The antifungal and antibacterial efficiencies were strongly enhanced upon complex formation. Cr(III) and Ni(II) complexes showed the strongest and promising anticancer activities (IC 50 = 7.64 and 6.99 μg/ml) among the tested compounds, whereas Cd(II) complex showed moderate anticancer efficiency (IC 50 = 12.10 μg/ml), compared with the 5-fluorouracil (applied standard drug) with IC 50 = 6.44 μg/ ml.