scholarly journals Synthesis¸ Characterization and Biological Activity of a Schiff Base Derived from 3-Ethoxy Salicylaldehyde and 2-Amino Benzoic acid and its Transition Metal Complexes

2010 ◽  
Vol 2 (3) ◽  
pp. 513 ◽  
Author(s):  
K. Mounika ◽  
A. Pragathi ◽  
C. Gyanakumari
Keyword(s):  
Schiff Base ◽  
Antifungal Activity ◽  
Benzoic Acid ◽  
Metal Complexes ◽  
Hydroxyl Group ◽  
Azomethine Nitrogen ◽  
Diffusion Method ◽  
Spectral Studies ◽  
Chemical Structures ◽  
Amino Benzoic Acid

A new Schiff base, 3-ethoxy salicylidene amino benzoic acid (ETSAN), has been synthesized from 3-ethoxy salicylaldehyde and 2-amino benzoic acid. Metal complexes of the Schiff base were prepared from nitrate/chloride salts of Ni(II), Co(II) Cu(II) and Zn(II) in an alcoholic medium. The complexes were non-electrolytes in dimethyl sulfoxide   solvent (DMSO). The chemical structures of the Schiff-base ligand and its metal complexes were confirmed by various spectroscopic studies like IR, UV-VIS, 1H NMR, 13C NMR, ESI-mass spectra, elemental analysis, molar conductance, thermogravimetric studies and magnetic susceptibility measurements. On the basis of elemental and spectral studies, six-coordinated geometry was assigned to these complexes. In the light of these results, it is suggested that this ligand acts as neutral and tridentate and coordinates to each metal atom by azomethine nitrogen and oxygen atoms of hydroxyl group of the 3-ethoxy salicylaldehyde, besides the hydroxyl group of the carboxyl group of 2-amino benzoic acid. The mass spectral data confirms the monomeric structure of the metal complexes while the TGA studies confirm the presence of water molecules in the complex. The free Schiff base and its complexes have been tested for their antibacterial as well as antifungal activity by using disc diffusion method and the results discussed. Keywords: Schiff base; 3-ethoxy salicylaldehyde; 2-amino benzoic acid; Metal complexes; Antibacterial activity; Antifungal activity. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i3.4899                 J. Sci. Res. 2 (3), 513-524 (2010) 

scholarly journals Synthesis, characterization, and biological evaluation of some 4-((thiophen-2-yl-methylene)amino)benzenesulfonamide metal complexes

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
E. Vijaya Sekhar ◽  
Subhas S. Karki ◽  
Javarappa Rangaswamy ◽  
Mahesh Bhat ◽  
Sujeet Kumar
Keyword(s):  
Escherichia Coli ◽  
Schiff Base ◽  
Aspergillus Niger ◽  
Metal Complexes ◽  
Antimicrobial Properties ◽  
Azomethine Nitrogen ◽  
Diffusion Method ◽  
Sulfa Drugs ◽  
Zone Of Inhibition ◽  
Penicillium Rubrum

Abstract Background Sulfonamides (sulfa drugs) and the metals like mercury, copper, and silver bear antimicrobial properties. The discovery of broad-spectrum antibiotics such as penicillins, cephalosporins, and fluoroquinolones has reduced their use. However, in some instances these drugs are the first-line treatment. The metal-based sulfonamide (e.g., silver sulfadiazine) is considered as first choice treatment in post-burn therapy while the use of silver nanoparticle-cephalexin conjugate to cure Escherichia coli infection explains the synergistic effect of sulfa drugs and their metal conjugates. With growing interest in metal-based sulfonamides and the Schiff base chemistry, it was decided to synthesize sulfonamide Schiff base metal complexes as antioxidant and antimicrobial agent. Results The Fe (III), Ru (III), Co (II), Ni (II), Cu (II), Pd (II), Zn (II), Cd (II), and Hg (II) metal complexes of 4-((thiophen-2-ylmethylene)-amino)-benzenesulfonamide (TMABS) were prepared and studied for thermal stability, geometry, and other electronic properties. The ligand TMABS (Schiff base) and its metal complexes were screened in-vitro for 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and antimicrobial properties against Gram-positive (+ve) Bacillus subtilis (MTCC-441), Staphylococcus aureus (MTCC 7443), Gram-negative (-ve) Escherichia coli (MTCC 40), Salmonella typhi (MTCC 3231), and fungal strains Aspergillus niger (MTCC-1344) and Penicillium rubrum by agar well diffusion method. Results summarized in Tables 3, 4, and 5 represent the inhibitory concentration (IC50) in micromole (μM). The zone of inhibition (ZI) in millimeter (mm) represents antimicrobial properties of TMABS and its metal complexes. Conclusions The synthesized sulfanilamide Schiff base (TMABS) behaved as a neutral and bidentate ligand coordinating with metal ions through its azomethine nitrogen and thiophene sulfur to give complexes with coordination number of 4 and 6 (Fig. 3). The nucleophilic addition of sulfanilamide amino group (–NH2) group to carbonyl carbon (>C=O) of benzaldehyde gave sulfanilamide Schiff base (imine) (Fig. 2). All the metal complexes were colored and stable at room temperature. With IC50 of 9.5 ± 0.1 and 10.0 ± 0.7 μM, the Co, Cu, and Pd complexes appeared better antioxidant than the ligand TMABS (155.3±0.1 μM). The zone of inhibition (ZI) of Hg (28 mm) and Ru complexes (20 mm) were similar to the ligand TMABS (20 mm) against Aspergillus niger (MTCC-1344) as in Figs. 4, 5, and 6. None of the synthesized derivatives had shown better antimicrobial properties than the standard streptomycin sulfate and fluconazole.

scholarly journals Synthesis, Characterization and Antimicrobial studies of Schiff base Ligand from amino acid L-arginine and its Cu(II), Ni(II),Co(II) complexesIJCTR.2019.130201

2020 ◽  
Vol 13 (2) ◽  
pp. 1-8
Author(s):  
R.K. Sree Devi ◽  
S. SudhaKumari
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Metal Ion ◽  
Electronic Absorption Spectra ◽  
Magnetic Data ◽  
Azomethine Nitrogen ◽  
Diffusion Method ◽  
Significant Activity ◽  
Antimicrobial Studies

Transition metal complexes of Cu(II), Ni(II), Co(II) with a Schiff base Ligand (R,Z)-2-(2-hydroxy-3-methoxybenzylideneamino)-5-guanidinopentanoic acid (HMA-GPA) was synthesized by the condensation of 2-hydroxy-3-methoxybenzaldehyde and L- Arginine. These were characterized by elemental analysis IR, UV, magnetic susceptibility and molar conductivity measurements. The IR spectra of the Ligand HMA-GPA and the metal complexes suggest that the Ligand coordinates the metal ion through azomethine nitrogen, carboxylate Oxygen and Oxygen of the phenolic -OH group. The electronic absorption spectra and magnetic data indicate the Cu(II), Ni(II)complexes to be square planar and Co(II) complex to be octahedral. The metal complexes and the ligand were subjected to antimicrobial studies by Kirby Bayer Disc-diffusion method and found to have significant activity against the selected bacterial and fungal strains under study.

scholarly journals Synthesis and Characterization of New Lead(II) and Organotin(IV) Complexes of Schiff Bases Derived from Histidine and Methionine

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Har Lal Singh ◽  
J. B. Singh
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Analytical Data ◽  
Molar Conductance ◽  
Molar Ratio ◽  
Azomethine Nitrogen ◽  
Spectral Studies ◽  
Tetrahedral Geometry ◽  
H Nmr ◽  
Carboxylate Oxygen

New Schiff base (HL) ligand is prepared via condensation of isatins and amino acids in 1:1 molar ratio. Metal complexes are prepared and characterized by elemental analysis, molar conductance, electronic, infrared, and multinuclear magnetic resonance (1H NMR, 13C NMR, and 119Sn NMR). The analytical data showed that the ligand acts as bidentate toward metal ions via azomethine nitrogen and carboxylate oxygen by a stoichiometric reaction of metal : ligand (1 : 2) to from metal complexes (Pb(II)(L)2 and Bu2Sn(L)2, where L is the Schiff base ligands of histidine and methionine). The conductivity values between 15 and 25 Ω−1cm2 mol−1 in DMF imply the presence of nonelectrolyte species. On the basis of the above spectral studies, distorted octahedral and tetrahedral geometry have been proposed for the resulting organotin(IV) and lead(II) complexes.

scholarly journals Synthesis, Characterizations and Antimicrobial Activity of Metal Complexes of 2-(2-Furanylmethylaminocarbonyl)benzoic Acid

2011 ◽  
Vol 8 (1) ◽  
pp. 443-448 ◽  
Author(s):  
R. H. Patel ◽  
B. L. Hiran
Keyword(s):  
Antimicrobial Activity ◽  
Antifungal Activity ◽  
Transition Metal ◽  
Benzoic Acid ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Elemental Analysis ◽  
Magnetic Moments ◽  
Thermal Studies ◽  
Spectral Studies

The ligand, 2-(2-furanylmethylaminocarbonyl)benzoic acid (FMBA) and it’s transition metal complexes have been synthesized and characterized by elemental analysis, spectral studies, magnetic moments and thermal studies. The antifungal activity of all the samples was monitored against common fungi.

scholarly journals Synthesis, Characterization, and Biological Evaluation of Some 3d-Metal Complexes of Schiff Base Derived from Xipamide Drug

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Suman Malik ◽  
Suparna Ghosh ◽  
Bharti Jain ◽  
Archana Singh ◽  
Mamta Bhattacharya
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Elemental Analysis ◽  
Biological Evaluation ◽  
Molar Conductance ◽  
Bidentate Ligand ◽  
Azomethine Nitrogen ◽  
Spectral Studies ◽  
Elemental Analysis Data ◽  
Central Metal

The present paper deals with the synthesis and characterization of metal complexes of Schiff base derived from xipamide, a diuretic drug. The bidentate ligand is derived from the inserted condensation of 5-aminosulfonyl-4-chloro-N-2,6-dimethyl phenyl-2-hydroxybenzamide (Xipamide) with salicylaldehyde in a 1 : 1 molar ratio. Using this bidentate ligand, complexes of Hg(II), Zn(II), and VO(IV) with general formula ML2 have been synthesized. The synthesized complexes were characterized by several techniques using molar conductance, elemental analysis, magnetic susceptibility, FT-IR spectroscopy, electronic spectra, mass spectra, and particle size analysis. The elemental analysis data suggest the stoichiometry to be 1 : 2 [M : L]. All the complexes are nonelectrolytic in nature as suggested by molar conductance measurements. Infrared spectral data indicate the coordination between the ligand and the central metal ion through deprotonated phenolic oxygen and azomethine nitrogen atoms. Spectral studies suggest tetrahedral geometry for Hg(II), Zn(II) complexes, and square pyramidal geometry for VO(IV) complex. The pure drug, synthesized ligand, and metal complexes were screened for their antifungal activities against Aspergillus niger and Aspergillus flavus. The ligand and its Hg(II) and VO(IV) complexes were screened for their diuretic activity too.

scholarly journals Synthesis, Characterization, and Biological Activity of Some Transition Metal Complexes Derived from Novel Hydrazone Azo Schiff Base Ligand

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
C. Anitha ◽  
S. Sumathi ◽  
P. Tharmaraj ◽  
C. D. Sheela
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Base Ligand ◽  
Second Harmonic ◽  
Biological Activities ◽  
Diffusion Method ◽  
Spectral Studies ◽  
Planar Geometry ◽  
Conductivity Measurements ◽  
Tetrahedral Geometry

A series of metal(II) complexes ML where M = VO(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from azo Schiff base ligand (N′E)-N′-(5-((4-chlorophenyl)diazenyl)-2-hydroxybenzylidene)-2-hydroxybenzohydrazide and characterized on the basis of elemental analyses, electronic, IR, and 1H NMR spectra, magnetic susceptibility and also by aid of scanning electron microscopy (SEM), X-ray powder diffraction, fluorescence spectral studies, and molar conductivity measurements. Conductivity measurements reveal that the complexes are nonelectrolytes. Spectroscopy and other analytical studies reveal distorted square planar geometry for copper, square-pyramidal geometry for oxovanadium, and tetrahedral geometry for other complexes. Redox behavior of the copper(II) complex has been studied with cyclic voltammetry, and the biological activities of the ligand and metal complexes have been studied against several microorganisms by the well diffusion method. All synthesized compounds can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic generation (SHG) efficiency of the ligand was measured and found to be higher than that of urea and KDP. The SEM image of the copper(II) complex implies that the size of the particles is 50 nm.

scholarly journals Synthesis, DFT and Bio-Potential Activities of Mn(II) and Hg(II) Complexes with Bidentate (E)-N′[(E)-3-Phenylallylidene]benzene-1,2-diamine

2021 ◽  
Vol 33 (6) ◽  
pp. 1222-1228
Author(s):  
R. Selvarani ◽  
S. Balasubramaniyan ◽  
K. Rajasekar ◽  
M. Thairiyaraja ◽  
R. Meenakshi
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Elemental Analysis ◽  
Magnetic Moment ◽  
Radical Scavenging ◽  
Molar Conductance ◽  
Diffusion Method ◽  
Spectral Studies ◽  
Planar Geometry ◽  
Dpph Method

A new bidentate Schiff base (E)-N′[(E)-3-phenylallylidene]benzene-1,2-diamine derived from the condensation of o-phenylenediamine and cinnamaldehyde and its Mn(II) and Hg(II) complexes were synthesized and characterized by elemental analysis, molar conductance, magnetic moment, electronic spectra, IR, far-IR and NMR (1H & 13C) spectral studies. The elemental analysis and these metal proposed the metal:ligand stoichiometry and molecular formulae of the metal complexes. The molar conductance and electrochemical property indicates monomeric, neutral nature and redox properties of the metal complexes. The UV-visible spectral study supports the octahedral geometry for Mn(II) complex and square planar geometry for Hg(II) complex and further confirmed by magnetic moment. IR spectral data examined the coordination mode but far-IR is useful to identify the metal-ligand vibrations. The geometry, magnetic property and unsymmetrical nature of these metal complexes corroborated by NMR (1H & 13C) spectra. The DFT of Mn(II) complex studied and the structure optimized by B3LYP/Lan L2DZ using Gaussian 09W. Quantum chemical calculations were done by Mullikan population analysis, HOMO-LUMO and molecular electrostatic potential. The in vitro biological screening effects of the investigated complexes were tested against some bacteria and fungus by agar-well diffusion method. The results indicated that Mn(II) and Hg(II) complexes exhibit potentially active than the Schiff base which was further confirmed by pharmacokinetics study. The antioxidant activity of Schiff base and its Mn(II) complex was examined by radical scavenging DPPH method.

Synthesis, Characterization and Biological Activity of Nitrogen­ Oxygen-Sulfur (NOS) Transition Metal Complexes Derived from Novel S-2,4-dichlorobenzyldithiocarbazate with 5-fluoroisatin

2010 ◽  
Vol 7 (2) ◽  
pp. 67
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
Hadariah Bahron ◽  
Karimah Kassim ◽  
Mohd Asrul Hafaz Mohamad ◽  
Syed Nazmi Sayed Mohamad
Keyword(s):  
Bacillus Subtilis ◽  
Schiff Base ◽  
Metal Complexes ◽  
Condensation Reaction ◽  
Schiff Base Complex ◽  
Inhibition Zone ◽  
Azomethine Nitrogen ◽  
Strong Activity ◽  
Chelating Ligand ◽  
Physico Chemical

A novel Schiff base containing nitrogen-oxygen-sulfur (NOS) donor atoms formed from the condensation reaction of S-2,4-dichlorobenzyldithiocarbazate (S-2,4BDTC) with 5-fluroisatin has been synthesized. Complexes of cobalt(II), nickel(II), copper(II), zinc(II) and cadmium(II) with this Schiff base have been prepared and characterized using elemental analysis and various physico-chemical techniques. In the cobalt(II) and nickel(II) complexes the Schiff base behaves as a uninegatively charged tridentate nitrogen-oxygen-sulfur (NOS) chelating ligand, bonding through the azomethine nitrogen, thiolate sulfur and carbonylic oxygen of the isatin moiety. However, in the copper(II), zinc(II) and cadmium(II) complexes the Schiff base behaves as a nitrogen-sulfur (NS) bidentate chelating ligand, bonding through the azomethine nitrogen and thiolate sulfur. The Schiff base and the metal complexes were evaluated with respect to antimicrobial activity, which was performed in relation to two selected pathogenic microbials (Bacillus subtilis and Pseudomonas aeruginosa). It was observed that only the zinc Schiff base complex exhibited strong activity against the Bacillus subtilis bacteria with an inhibition zone of 25 mm. 

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