Browsing by Author "Benali-Baitich, Ouassini"

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    Synthesis, characterization, electrochemical studies and DFT calculations of amino acids ternary complexes of copper (II) with isonitrosoacetophenone. Biological activities
    (Elsevier, 2014) Tidjani-Rahmouni, Nabila; Bensiradj, Nour el Houda; Djebbar, Safia; Benali-Baitich, Ouassini
    Three mixed complexes having formula [Cu(INAP)L(H2O)2] where INAP = deprotonated isonitrosoacetophenone and L = deprotonated amino acid such as histidine, phenylalanine and tryptophan have been synthesized. They have also been characterized using elemental analyses, molar conductance, UV–Vis, IR and ESR spectra. The value of molar conductance indicates them to be non-electrolytes. The spectral studies support the binding of the ligands with two N and two O donor sites to the copper (II) ion, giving an arrangement of N2O2 donor groups. Density Functional Theory (DFT) calculations were applied to evaluate the cis and trans coordination modes of the two water molecules. The trans form was shown to be energetically more stable than the cis one. The ESR data indicate that the covalent character of the metal–ligand bonding in the copper (II) complexes increases on going from histidine to phenylalanine to tryptophan. The electrochemical behavior of the copper (II) complexes was determined by cyclic voltammetry which shows that the chelate structure and electron donating effects of the ligands substituent are among the factors influencing the redox potentials of the complexes. The antimicrobial activities of the complexes were evaluated against several pathogenic microorganisms to assess their antimicrobial potentials. The copper complexes were found to be more active against Gram-positive than Gram-negative bacteria
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    Synthesis, characterization, solution equilibria, DFT study, DNA binding affinity and cytotoxic properties of a cobalt(II) complex with a 5-pyrazolone ligand
    (Elsevier, 2018-07-07) Akcha, Selma; Gomez-Ruiz, Santiago; Kellou-Tairi, Safia; Lezama, Luis; Pérez, Frank Blanco; Benali-Baitich, Ouassini
    Our work describes the synthesis, the complexation and the characterization of a cobalt(II) complex with a 5- pyrazolone ligand carrying a thioamide group on N1 position. The study of the complexation in solution allowed the determination of the stability constants of the complex and the distribution of the species involving Co(II) over the whole pH-range. The solid cobalt(II) complex has then been synthesized and fully characterized by infrared, electronic, EPR and mass spectrometries, in addition to magnetic and voltammetric measurements. The data clearly indicated an octahedral high spin Co(II) complex with two mononegative molecules of the N,Sligand, and two water molecules, likely in a cis position because of the high anisotropy. DFT calculations performed on both the ligand and the complex structures allowed us to study the spectral features, and to propose the most fitting structures to the experimental data. The interaction of the 5-pyrazolone ligand and its Cobalt(II) complex with fish-sperm DNA has been studied by electronic spectrometry and cyclovoltammetry. Intercalation has been identified as a binding mode and the strength of the binding assessed. In order to explore eventual cytotoxic and/or cytostatic properties of our compounds, the ligand and the cobalt complex have been tested on PC-3 (human prostate carcinoma) and HT-29 (human colon carcinoma) using sulphorhodamine B (SRB) assay.