Preparation, characterization, and antibacterial properties of mixed ligand (original) (raw)
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Antibacterial Studies and Schiff Base Metal Complexes with Some Novel Antibiotics
The work presented in this paper is related to the preparation, characterization and biological evaluation of Zn(II), Cu(II), Ni(II), Co(II), Mn(II), Cr(II) and Cd(II) transition metal complexes of Schiff bases salicylidenegemifloxacin derived from Gemifloxacin and Salicylaldehyde. In these complexes amino group available in the drug substances was allowed to react with Salicylaldehyde, to obtain Schiff bases which were, subsequently, allowed to react with Zn(CH3COO)2.2H2O, Cu(CH3COO)2.H2O, NiCl2.6H2O, CoCl2.6H2O, MnCl2.4H2O, CrCl3.6H2O and CdCl2.2.5 H2O separately to form Schiff base metal complexes. The Schiff base prepared was salicylidenegemiflxacin, and metal complexes were: Salicylidenegemifloxcin-M(II).2H2O Where (M= Zn, Cu, Ni, Co, Mn, Cr and Cd). The Schiff base ligands and the transition metal (Zn(II), Cu(II), Ni(II), Co(II), Mn(II), Cr(II) and Cd(II)) complexes of Schiff bases prepared were characterized on the basis of physical properties, conductance measurements, thermogravimetry, UV-Visible spectroscopy, FT-IR spectroscopy, atomic absorption spectroscopy and NMR spectroscopy. Schiff base was obtained by reacting salicyldehyde with amino group present in antibiotic in equimolar quantities (1:1). Transition metal compolexes were obtained by subsequently reacting metal salts with Schiff bases. The complexes were found to be ML2 type. Conductance measurements showed that complexes were non-electrolytes. Thermogravimetric analysis showed that the complexes were hydrated. The IR study showed that ligand is a bidentate and coordinate to the central metal ion though the azomethine nitrogen -C=N and the oxygen OH of phenol. All the complexes under investigation possess antibacterial activity. NMR studies confirmed prescence of -C=N group singlet at 8.6 ppm. The singlet at 8.6 ppm for -C=N-shifted to downfield because of complexation in salicylidenegemifloxacin-Zn(II).2H2O. The antibacterial activity showed the following trend: Metal complexes > Schiff base ligands> Parent drugs.
The Co (II), Ni (II) ,Cu(II), Zn(II) ,Cd(II) and Hg(II) complexes of mixed of amino acid (L-Alanine) and Trimethoprim antibiotic were synthesized. The complexes were characterized using melting point, conductivity measurement and determination the percentage of the metal in the complexes by flame (AAS). Magnetic susceptibility, Spectroscopic Method [FT-IR and UV-Vis]. The general formula have been given for the prepared mixed ligand complexes [M(Ala) 2(TMP)(H 2 O)] where L-alanine (abbreviated as (Ala) = (C 5 H 9 NO 2) deprotonated primary ligand, L-Alanine ion .= (C 5 H 8 NO 2-) Trimethoprim (abbreviated as (TMP) = C 10 H 11 N 3 O 3 S M(II) = Co (II),Ni(II) ,Cu(II), Zn(II) ,Cd(II) and Hg(II). The results showed that the deprotonated L-Alanine by KOH (Ala-K+) act as uni nagative bi dentate ligand , was coordinated to the metal ions through the oxygen of the carboxylic group (−COO −), and the nitrogen of the amine group (−NH 2) while Trimethoprim antibiotic act as mono dentate ligand , was coordinated to the metal ions through the nitrogen of the pyrimidine group.
mixed ligand complexesMixed Ligand Complexes of Saccharin and Β-Lactams Antibiotics
Chelating ligands in the field of coordination chemistry and their metal complexes are of great interest since many years. It is well known that N, S and O atoms play a key role in the coordination of metals at the active sites of numerous metallobiomolecules. Chelating ligands containing O, N and S donor atoms show broad biological activity and are of special interest because of the variety of ways in which they are bonded to metal ions
International Journal of Health Sciences (IJHS), 2022
New Azo-Schiff base ligand [4-((E)-(2hydroxyphenyl)diazenyl)-3-(((1E,2E)-2-((2-((E)-(2hydroxyphenyl)diazenyl)-5-(N-(pyrimidin-2-yl)sulfamoyl)phenyl)imino)-1,2-diphenylethylidene)amino)-N-(pyrimidin-2-yl)benzenesulfonamide] (4HDPS) was primed. Three chelate complexes have correspondingly been equipped by reacting this ligand (4HDPS) with the metal ions Co (II), Ni (II) and Cu (II). (UV-Vis) electronic spectra of complexes showed bathchromic shift, as compared with that of free ligand .The Mass Spectrum and 1HNMR Spectrum of the free ligand has been taken and the FTIR spectrums of the Ligand and its chelating complexes have been investigated. This may specify that coordination among the metal ions and the equipped ligand takes place .The conductivity and magnetic measurements, Elemental micro analysis and the percentage of metal ions were determined. Based on these consequences, the proposed geometrical structures of the equipped complexes of Co(II),Ni(II) and Cu(II).ions are octahedral with mole ratio (M:L) was (1:1) for all prepared complexes while the conductivity measurements shows non-electrical properties. The final stage involved the study of the biological activity of prepared component to two type of pathogenic bacteria: (G+) Staph. Aureus and Escherichia coli (G-) using Well diffusion methods. Three different concentration were tested (100, 500, 1000) ppm in Ethanol Absolute (99%) as a 5525 solvent. The prepared compounds showed different results (high, moderate, low, and inactive). While the new prepare Azo-Schiff (4HDPS) showed less inhibition growth against both type of bacteria in comparison with its complexes. Also, the metallic ligand complexes showed more inhibition activity against Gram positive than Gram negative.
A new azo sulfoxine ligand was produced from coupling reaction between 8-hydroxyquinoline-5-sulfonic acid (H 2 L 1 ) and 4-amino antipyrene. The structure of the new azo ligand, 7-azo(-4-antipyrene)-8-hydroxyquinoline-5-sulfonic acid (H 2 L 2 ), was confirmed by various physico-chemical techniques. The molecular structures of H 2 L 1 and its azo derivative (H 2 L 2 ) were optimized theoretically and the quantum chemical parameters were calculated. Molecular docking was used to predict the efficiency of binding between each ligand and the breast cancer mutant receptor (3hb5-Oxidoreductase). The acid dissociation constants (pK H ) of H 2 L 1 and H 2 L 2 ligands have been determined potentiometrically at different temperatures. The stability constants (log K) of some transition metal ions (Mn 2+ , Co 2+ , Ni 2+ and Cu 2+ ) with the investigated ligands have been determined. The effect of the azo group on both, the dissociation constants of H 2 L 2 ligand and the stability constants of its complexes has been discussed. The thermodynamic parameters (ΔG, ΔH and ΔS) were derived and discussed at different temperatures. The formation of the metal complexes was found to be spontaneous, endothermic and entropically favorable. The relationships between the stability constants and ΔG values of all investigated complexes and their ionic radii have been discussed and correlated.
Inorganic Chemistry Communications, 2020
The emergence of old and new antibiotic resistance created in the last decades revealed a substantial medical need for new classes of antimicrobial agents. The antimicrobial activity of sulfa drugs is often enhanced by complexation with metal ions, which is in concordance with the well-known importance of metal ions in biological systems. Besides, sulfonamides and its derivatives constitute an important class of drugs, with several types of pharmacological agents possessing antibacterial, anti-carbonic anhydrase, diuretic, hypoglycemic, antithyroid, antiviral and anticancer activities, among others.
Transition Metal Chemistry, 2003
To investigate the relationship between antimicrobial activities and the formation constants of CuII, NiII and CoII complexes with three Schiff bases, which were obtained by the condensation of 2-pyridinecarboxyaldehyde with DL-alanine, DL-valine and DL-phenylalanine, have been synthesized. Schiff bases and the complexes have been characterized on the basis of elemental analyses, magnetic moments (at ca. 25 °C), molar conductivity, thermal analyses and spectral (i.r., u.v., n.m.r.) studies. The i.r. spectra show that the ligands act in a monovalent bidentate fashion, depending on the metal salt used and the reaction pH = 9, 8 and 7 medium, for CuII, NiII and CoII, respectively. Square-planar, tetrahedral and octahedral structures are proposed for CuII, NiII and CoII, respectively. The protonation constants of the Schiff bases and stability constants of their ML-type complexes have been calculated potentiometrically in aqueous solution at 25 ± 0.1 °C and at 0.1 M KCl ionic strength. Antimicrobial activities of the Schiff bases and the complexes were evaluated for three bacteria (Bacillus subtillis, Staphylococcus aureus, and Escherichia coli) and a yeast (Candida albicans). The structure–activity correlation in Schiff bases and their metal(II) complexes are discussed, based on the effect of their stability contants.
Chemical and Process Engineering Research, 2014
A series of ciproH antibiotic drug complexes was prepared. Cu(II), VO(II), Pd(II), Zn(II), Pt(II) and Pt(IV) are the metal ions used for the preparations. The chosen ions have a great history in the medicinal field which may introduce a sensitive antibiotic appearance in comparing with the free ciproH drug. All the prepared complexes are discussed briefly based on spectral (IR, 1 HNMR, 13 CNMR, Uv-Vis, ESR, X-ray and SEM), thermal and analytical data. The ligand coordinates through its zwitterionic form as bidentate mod through COOand C=O groups. The octahedral stereo structure was prepared with Cu(II), Zn(II) and Pt(IV) ions, square planer with Pd(II) and Pt(II) ions however, the square-pyramidal with VO(II) ion. The amorphous nature was proposed for all investigated complexes based on the x-ray diffraction patterns although, the nanocrystalline appearance of starting ligand. Thermogravimetric analysis is also used to support the presence or absence of solvent molecules conjugated with the complexes isolated physically or chemically. Applying Chem-office program a suitable modeling structure of each investigated complex was drawn. A comparative antibacterial study was concerned using Gramm-ve and Gramm +ve bacteria. The data reflect the inhibiting effect of some complexes more than the drug itself which is considered an introductory step in introducing competitive drug.