scholarly journals Synthesis, Characterization and Biological Evaluation of New Schiff Base Ligand derived from 3-hydroxy-benzaldehyde and p-toluidine and its Divalent Metal Ions

2020 ◽  
Vol 71 (4) ◽  
pp. 47-58
Author(s):  
Noreen Mazhar ◽  
Mehwish Aftab ◽  
Tariq Mahmud ◽  
Muhammadasim Raza Basra ◽  
Mansoor Akhtar ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Protein Denaturation ◽  
Condensation Reaction ◽  
Free Ligand ◽  
Biological Evaluation ◽  
Divalent Metal ◽  
Anti Inflammatory

A new Schiff base ligand (L) and its transition divalent metal complexes were prepared by the condensation reaction; Reaction was carried out at 70-80 oC by refluxing equimolar ratio of toluidine and aldehyde by continuous stirring for 5-6 hours. Synthesized ligand and Ni(II), Fe(II), Co(II), Mn(II) and Zn(II) bimetallic complexes were characterized by using FT-IR, UV-visible spectroscopy, AAS, Single crystal X-ray analysis, 1H-NMR, molar conductance. Compounds were screened against two fungus Candida glabrata and Candida albicans by agar tube dilution protocol. In vivo anti-inflammatory activity via induced paw edema method and in vitro results by heat induced protein denaturation method were checked. Synthesized compounds were also showed antioxidant activity by using DPPH (diphenylpicrylhydrazyl) and Trolox was used as standard. These studies show that ligand and almost all metal complexes are reactive towards biological assays against reported standard drugs. Zn-L indicates more activeness for antioxidant activity and free ligand while Co-L recognized as more effective anti-inflammatory drug.

scholarly journals Synthesis, Characterization and Biological Evaluation of Schiff Base (N-4-(thiophene-2-yl-methyleneamino)-2,6-dimethylpyrimidine-4-yl)benzenesulfonamide and its Complexes with Cu(II), Ni(II), Co(II), Fe(II), Mn(II), Zn(II) Ions

2020 ◽  
Vol 71 (1) ◽  
pp. 206-212 ◽  
Author(s):  
Amina Mumtaz ◽  
Tariq Mahmud ◽  
M. R. J. Elsegood ◽  
G. W. Weaver ◽  
Gabriel Bratu ◽  
...  
Keyword(s):  
Schiff Base ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Schiff Base Ligand ◽  
Condensation Reaction ◽  
Klebsiella Oxytoca ◽  
Biological Evaluation ◽  
Anti Inflammatory

Two step synthesis of Schiff base ligand and its transition metal complexes was done by condensation reaction. In first step, the drug and aldehyde in equimolar ratio were refluxed for one hour at pH 8-9 in order to get Schiff base ligand. In second step, ligand and metal salts were refluxed for 2 hour. The ligand and Cu(II), Ni(II), Co(II), Fe(II), Mn(II), Zn(II) complexes were characterized by using different instruments like FT-IR, 1H-NMR, 13C-NMR, Mass, Atomic absorption spectrometer, Elemental analyzer, UV-visible spectrophotometer, Evans balance, Conductivitymeter and Thermogravimeter. In vitro antibacterial, antifungal and anti-inflammatory activities were also studied. The synthesized ligand and transition metal complexes were tested against Escherichia coli, Enterobacter aerogenes, Staphylococcus aureus, Bacillus pumilus, Klebsiella oxytoca, Clostridium butyrium, Mucor and Aspergillus niger. These studies demonstrated the enhanced activity of metal complexes against reported bacterial and fungal strains when compared with free Schiff base ligand. The Cu(II) complex recognized as anti-inflammatory agent while the parent drug showed no activity.

scholarly journals Metal Complexes of Macrocyclic Schiff-Base Ligand: Preparation, Characterisation, and Biological Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Riyadh M. Ahmed ◽  
Enaam I. Yousif ◽  
Hasan A. Hasan ◽  
Mohamad J. Al-Jeboori
Keyword(s):  
Biological Activity ◽  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Condensation Reaction ◽  
Free Ligand ◽  
Inhibition Zone ◽  
Square Planar ◽  
Planar Geometries ◽  
Macrocyclic Schiff Base

A new macrocyclic multidentate Schiff-base ligand Na4L consisting of two submacrocyclic units (10,21-bis-iminomethyl-3,6,14,17-tricyclo[17.3.1.18,12]tetracosa-1(23),2,6,8,10,12(24),13,17,19,21,-decaene-23,24-disodium) and its tetranuclear metal complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) are reported. Na4L was prepared via a template approach, which is based on the condensation reaction of sodium 2,4,6-triformyl phenolate with ethylenediamine in mole ratios of 2 : 3. The tetranuclear macrocyclic-based complexes were prepared from the reaction of the corresponding metal chloride with the ligand. The mode of bonding and overall geometry of the compounds were determined through physicochemical and spectroscopic methods. These studies revealed tetrahedral geometries about Mn, Co, and Zn atoms. However, square planar geometries have been suggested for NiIIand CuIIcomplexes. Biological activity of the ligand and its metal complexes against Gram positive bacterial strainStaphylococcus aureusand Gram negative bacteriaEscherichia colirevealed that the metal complexes become more potentially resistive to the microbial activities as compared to the free ligand. However, these metal complexes do not exhibit any effects on the activity ofPseudomonas aeruginosabacteria. There is therefore no inhibition zone.

Synthesis, Characterization and in vitro Biological Evaluation of a New Schiff Base Derived from Drug and its Complexes with Transition Metal Ions

2018 ◽  
Vol 69 (7) ◽  
pp. 1678-1681
Author(s):  
Amina Mumtaz ◽  
Tariq Mahmud ◽  
M. R. J. Elsegood ◽  
G. W. Weaver
Keyword(s):  
Schiff Base ◽  
Transition Metal ◽  
Metal Ions ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Free Ligand ◽  
Transition Metal Ions ◽  
Biological Evaluation ◽  
Pyridoxal Hydrochloride

New series of copper (II), cobalt (II), zinc (II), nickel (II), manganese (II), iron (II) complexes of a novel Schiff base were prepared by the condensation of sulphadizine and pyridoxal hydrochloride. The ligand and metal complexes were characterized by utilizing different instrumental procedures like microanalysis, thermogravimetric examination and spectroscopy. The integrated ligand and transition metal complexes were screened against various bacteria and fungus. The studies demonstrated the enhanced activity of metal complexes against reported microbes when compared with free ligand.

scholarly journals Synthesis, Characterization and Biological Evaluation of Fe(III) and Cu(II) Complexes with 2,4-Dinitrophenyl hydrazine and Thiocyanate Ions

2019 ◽  
Vol 31 (4) ◽  
pp. 780-784
Author(s):  
P. Manimaran ◽  
S. Balasubramaniyan
Keyword(s):  
Antioxidant Activity ◽  
Metal Complexes ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Ligand ◽  
Antimicrobial Activities ◽  
Biological Evaluation ◽  
Diffusion Method ◽  
Spectral Studies

The metal complexes of Fe(III) and Cu(II) were prepared by using 2,4-dinitrophenyl hydrazine (DNPH) and thiocyanate (SCN) with stirrer refluxed for about 6 h. The prepared Fe(III) and Cu(II) complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility and electronic spectrum, FT-IR spectral studies. The result suggested the octahedral geometry for Fe(III) and Cu(II) complexes. Powder X-ray diffraction indicate the crystalline nature of the metal complexes. The antimicrobial activities of the Fe(III) and Cu(II) complexes were tested with various micro organisms by disc diffusion method. The antimicrobial results indicate that the metal complexes are highly active with compared to the free ligand. The in vitro antioxidant activity of the free ligand and its metal complexes was assayed by radical scavenging activity (DPPH). The result proposed that Fe (III) and Cu(II) complexes exhibited strong antioxidant activity than that of the ligand.

scholarly journals Synthesis and Spectral Studies of 4,4′-(Hydrazine-1,2-diylidenedimethylylidene)-bis-(2- methoxyphenol) and Its Transition Metal Complexes with Promising Biological Activities

2020 ◽  
Vol 32 (7) ◽  
pp. 1768-1772
Author(s):  
Anita Rani ◽  
Manoj Kumar ◽  
Hardeep Singh Tuli ◽  
Zahoor Abbas ◽  
Vinit Prakash
Keyword(s):  
Schiff Base ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Schiff Base Ligand ◽  
Biological Activities ◽  
Condensation Reaction ◽  
Analytical Techniques ◽  
Spectral Studies

The study describes the synthesis, characterization and biological activity of a novel Schiff base ligand and its transition metal complexes. The Schiff base ligand was obtained by a condensation reaction between 4-hydroxy-3-methoxybenzaldehyde (p-vanillin) and hydrazine hydrate using ethanol as solvent. A new series of Ni(II) and Fe(III) complexes were also derived by reaction of prepared Schiff base ligand with NiCl2 and FeCl3. Both the ligand and its metal complexes were characterized by solubility, melting point and elemental analysis. These compounds were further identified by analytical techniques, FTIR, NMR and mass spectrometry. The ligand and its transition metal complexes were also subjected to in vitro biological activities i.e. antimicrobial, antiangiogenic and DNA photo cleavage. For antimicrobial activity compounds were tested against two strains of bacteria and two strains of fungi. Different concentrations of prepared compounds were treated with fertilized chicken eggs and plasmid DNA to find out antiangiogenic and DNA photocleavage activity, respectively.

scholarly journals Synthesis, Spectroscopy, Theoretical, and Electrochemical Studies of Zn(II), Cd(II), and Hg(II) Azide and Thiocyanate Complexes of a New Symmetric Schiff-Base Ligand

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Morteza Montazerozohori ◽  
Kimia Nozarian ◽  
Hamid Reza Ebrahimi
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Structural Parameters ◽  
Free Ligand ◽  
Basis Set ◽  
Cyclic Voltammograms ◽  
Hybrid Functional ◽  
Ft Ir ◽  
C Nmr

Synthesis of zinc(II)/cadmium(II)/mercury(II) thiocyanate and azide complexes of a new bidentate Schiff-base ligand (L) with general formula of MLX2(M = Zn(II), Cd(II), and Hg(II)) in ethanol solution at room temperature is reported. The ligand and metal complexes were characterized by using ultraviolet-visible (UV-visible), Fourier transform infrared (FT-IR),1H- and13C-NMR spectroscopy and physical characterization, CHN analysis, and molar conductivity.1H- and13C-NMR spectra have been studied in DMSO-d6. The reasonable shifts of FT-IR and NMR spectral signals of the complexes with respect to the free ligand confirm well coordination of Schiff-base ligand and anions in an inner sphere coordination space. The conductivity measurements as well as spectral data indicated that the complexes are nonelectrolyte. Theoretical optimization on the structure of ligand and its complexes was performed at the Becke’s three-parameter hybrid functional (B3) with the nonlocal correlation of Lee-Yang-Parr (LYP) level of theory with double-zeta valence (LANL2DZ) basis set using GAUSSIAN 03 suite of program, and then some theoretical structural parameters such as bond lengths, bond angles, and torsion angles were obtained. Finally, electrochemical behavior of ligand and its complexes was investigated. Cyclic voltammograms of metal complexes showed considerable changes with respect to free ligand.

scholarly journals Synthesis, Characterization and Antibacterial Activity of Schiff Base, 4-Chloro-2-{(E)-[(4-Fluorophenyl)imino]methyl}phenol Metal (II) Complexes

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
F. K. Ommenya ◽  
E. A. Nyawade ◽  
D. M. Andala ◽  
J. Kinyua
Keyword(s):  
Antibacterial Activity ◽  
Schiff Base ◽  
Metal Complexes ◽  
Elemental Analysis ◽  
Schiff Base Ligand ◽  
Condensation Reaction ◽  
Molar Conductance ◽  
Diffusion Method ◽  
Elemental Analysis Data ◽  
Ft Ir

A new series of Mn (II), Co (II), Ni (II), Cu (II), and Zn (II) complexes of the Schiff base ligand, 4-chloro-2-{(E)-[(4-fluorophenyl)imino]methyl}phenol (C13H9ClFNO), was synthesized in a methanolic medium. The Schiff base was derived from the condensation reaction of 5-chlorosalicylaldehyde and 4-fluoroaniline at room temperature. Elemental analysis, FT-IR, UV-Vis, and NMR spectral data, molar conductance measurements, and melting points were used to characterize the Schiff base and the metal complexes. From the elemental analysis data, the metal complexes formed had the general formulae [M(L)2(H2O)2], where L = Schiff base ligand (C13H9ClFNO) and M = Mn, Co, Ni, Cu, and Zn. On the basis of FT-IR, electronic spectra, and NMR data, “O” and “N” donor atoms of the Schiff base ligand participated in coordination with the metal (II) ions, and thus, a six coordinated octahedral geometry for all these complexes was proposed. Molar conductance studies on the complexes indicated they were nonelectrolytic in nature. The Schiff base ligand and its metal (II) complexes were tested in vitro to evaluate their bactericidal activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus subtilis and Staphylococcus typhi) using the disc diffusion method. The antibacterial evaluation results revealed that the metal (II) complexes exhibited higher antibacterial activity than the free Schiff base ligand.

scholarly journals Synthesis, Characterization and Electrochemical Sensor Based Upon Novel Schiff Base Metal Complexes Derived from the Non-Steroidal Anti-inflammatory Drug, Flufenamic Acid for the Determination of Uric acid and their Biological Applications

2020 ◽  
Vol 11 (4) ◽  
pp. 11390-11403
Keyword(s):  
Uric Acid ◽  
Schiff Base ◽  
Metal Complexes ◽  
Base Metal ◽  
Schiff Base Ligand ◽  
Flufenamic Acid ◽  
Spectral Studies ◽  
Anti Inflammatory ◽  
Schiff Base Metal Complexes

The current trend in coordination chemistry is the design and synthesis of new Schiff base transition metal complexes for therapeutic, diagnostic, and catalytic applications. For decades, it has been observed that special attention is being paid to the chemistry of Schiff base metal complexes because of their wide range of applications. Therefore the present paper involves the synthesis of Schiff base ligand by altering the functional group of the drug, Flufenamic acid. From that Schiff base ligand, four complexes, i.e., Co(II), Cu(II), Ni(II), and Zn(II) have been prepared (SB metal complexes). The synthesized SB metal complexes have been characterized using several spectral and analytical techniques. All the metal complexes show non-electrolytic behavior suggested by molar conductance measurements. Spectral studies suggest that all four metal complexes exhibit octahedral geometry. The modified SB-Co complex/GCE showed a greater electro-catalytic activity and lower potential towards the oxidation of uric acid (UA). The response of UA was linear over the concentration ranging from CV is 0.5–1.8 μmol/L, sensitivity for 131.85 μAμM-1cm-2, and detection limit for 0.16 μM (S/N=3). The modified GCE showed very good sensitivity along with good repeatability and reproducibility for the determination of UA. The pure drug, Schiff base ligand, and metal complexes, were also screened for anti-inflammatory and antibacterial activities. The observed results prove that the metal complexes exhibit greater activity than that of the original drug.

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