scholarly journals Synthesis, Characterization, Cyclic Voltammetry, and Biological Studies of Co(II), Ni(II), and Cu(II) Complexes of a Tridentate Schiff Base, 1-((E)-(2-Mercaptophenylimino) Methyl) Naphthalen-2-ol (H2L1)

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Maurice Kuate ◽  
Mariam Asseng Conde ◽  
Evans Ngandung Mainsah ◽  
Awawou G. Paboudam ◽  
Francis Merlin M. Tchieno ◽  
...  

A novel tridentate Schiff base, 1-((E)-(2-mercaptophenylimino) methyl) naphthalen-2-ol (H2L1), was synthesized by the condensation reaction of 2-hydroxy-1-naphthaldehyde with 2-aminothiophenol in absolute ethanol. The resulting ligand was reacted with Co(II), Ni(II), and Cu(II) ions to obtain tetrahedral CoL1, NiL1, and square planar CuL1 complexes. The Schiff base and its metal complexes were characterized using 1H-NMR, microanalysis, FT-IR, UV-visible, and mass spectroscopy (ESI-MS). All the compounds are soluble in DMSO and DMF. Spectroscopic studies show that the ligand coordinates to the metal center through the azomethine nitrogen, naphthoxide oxygen, and thiophenoxide sulfur to form a tridentate chelate system. Conductance measurements show that these compounds are molecular in solution. Cyclic voltammetry studies show Co(III)/Co(II) and Cu(II)/Cu(I) redox systems to be quasi-reversible involving a monoelectronic transfer while Ni(III)/Ni(II) was irreversible. In vitro antibacterial and antifungal activity against five bacterial strains (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, and Proteus mirabilis) and five fungal strains (Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei, and Candida parapsilosis) showed no antifungal activity but moderate antibacterial activity on E. coli, S. aureus, P. aeruginosa, and P. mirabilis bacterial strains. Antioxidant studies reveal that the ligand and its Cu(II) complex are more potent than Co(II) and Ni(II) complexes to eliminate free radicals.

2021 ◽  
Vol 35 (1) ◽  
pp. 97-106
Author(s):  
A. O. Rajee ◽  
H. F. Babamale ◽  
A. Lawal ◽  
A. A. Aliyu ◽  
W. A. Osunniran ◽  
...  

Four complexes of Mn(II), Co(II), Ni(II) and Cu(II) with Schiff base ligand (H3L) derived from 2-amino-3-methylbutanoic acid and acetylacetonate were synthesized. All complexes were characterized by elemental analysis, Fourier-transform infrared spectroscopy and electronic spectroscopy. The results confirmed the coordination of the ligand to metals in tridentate fashion via the hydroxyl oxygen, the azomethine nitrogen and the enolic acetylacetonate oxygen. Antimicrobial activities were established for all complexes, free ligand and ciprofloxacin for comparison. Both the ligand and its metal complexes were active against Gram-positive and negative bacterial strains. The Cu(II) complex, showed highest antibacterial activity among the complexes screened. Other complexes displayed considerable antibacterial activity. Octahedral geometry was proposed for the metal(II) complexes with the Schiff base.                     KEY WORDS: Schiff base, Amino acid, Metal Complexes, Antibacterial agents   Bull. Chem. Soc. Ethiop. 2021, 35(1), 97-106. DOI: https://dx.doi.org/10.4314/bcse.v35i1.8


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

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. 


2010 ◽  
Vol 7 (2) ◽  
pp. 67
Author(s):  
Mohd Abdul Fatah Abdul Manan ◽  
Hadariah Bahron ◽  
Karimah Kassim ◽  
Mohd Asrul Hafiz Muhamad ◽  
Syed Nazmi Sayed Mohamad

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(ll), nickel(ll), copper(ll), zinc(ll) and cadmium(ll) with this Schiff base have been prepared and characterized using elemental analysis and various physico-chemical techniques. In the cobalt(ll) and nickel(II) complexes the SchifJbase 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(ll), 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 reallion to two selected pathogenic microbials (Bacillus subtilis and Pseudomonas aeruginosa). It was observed that only the zinc Schiffbase complex exhibited strong activity against the Bacillus subtilis bacteria with an inhibition zone of25 mm.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3854
Author(s):  
Joanna Czechowska ◽  
Ewelina Cichoń ◽  
Anna Belcarz ◽  
Anna Ślósarczyk ◽  
Aneta Zima

Bioactive, chemically bonded bone substitutes with antibacterial properties are highly recommended for medical applications. In this study, biomicroconcretes, composed of silicon modified (Si-αTCP) or non-modified α-tricalcium phosphate (αTCP), as well as hybrid hydroxyapatite/chitosan granules non-modified and modified with gold nanoparticles (AuNPs), were designed. The developed biomicroconcretes were supposed to combine the dual functions of antibacterial activity and bone defect repair. The chemical and phase composition, microstructure, setting times, mechanical strength, and in vitro bioactive potential of the composites were examined. Furthermore, on the basis of the American Association of Textile Chemists and Colorists test (AATCC 100), adapted for chemically bonded materials, the antibacterial activity of the biomicroconcretes against S. epidermidis, E. coli, and S. aureus was evaluated. All biomicroconcretes were surgically handy and revealed good adhesion between the hybrid granules and calcium phosphate-based matrix. Furthermore, they possessed acceptable setting times and mechanical properties. It has been stated that materials containing AuNPs set faster and possess a slightly higher compressive strength (3.4 ± 0.7 MPa). The modification of αTCP with silicon led to a favorable decrease of the final setting time to 10 min. Furthermore, it has been shown that materials modified with AuNPs and silicon possessed an enhanced bioactivity. The antibacterial properties of all of the developed biomicroconcretes against the tested bacterial strains due to the presence of both chitosan and Au were confirmed. The material modified simultaneously with AuNPs and silicon seems to be the most promising candidate for further biological studies.


2020 ◽  
Vol 8 (1) ◽  
pp. 01-11
Author(s):  
Sameer Amereih ◽  
Abd Daraghmeh ◽  
Ismail Warad ◽  
Mohammed Al-Nuri

Condensation reaction of naphthalene -2-Sulfonylhydrazide, as starting material with 2,5-dimethoxy benzaldehyde was used to produce (E)-N’-(2,5-dimethoxybenzalidene)naphthalene-2-sulfonohydrazide. The Schiff base product was isolated, purified and then spectrally characterized via UV-Vis, GC/MS, FT-IR, 1H and 13C NMR analysis, where strong evidences confirmed the formation of the desired product. Antimicrobial activity of Schiff base product was evaluated in vitro against several types of bacteria such as: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae and MRSA by Minimum Inhibitory Concentration (MIC) test using tetracycline (TE) as a standard antibiotic. The tests showed a promising bacteriostatic effect of this compound against gram negative bacteria such as P. aeruginosa and K. pneumoniae, such character is valuable for biological applications.


2020 ◽  
Vol 32 (10) ◽  
pp. 2553-2558
Author(s):  
Jyoti Yadav ◽  
Jai Devi

Novel diorganotin(IV) complexes were synthesized from 1,2,4-triazole Schiff base ligands which were synthesized by reaction between the 4-amino-5-phenyl-1,2,4-triazole-3-thiol and salicyaldehyde derivatives. The bonding and geometry of the diorganotin(IV) complexes were evaluated by using different spectroscopic techniques such as FT-IR, mass, 1H, 13C & 119Sn NMR. The different spectroscopic techniques revealed the tridentate (ONS) mode of chelation of Schiff base ligands and pentacoordinated environment around the central tin metal which was satisfied with azomethine nitrogen, phenolic oxygen, thiolic sulfur and metal-carbon bond of alkyl/aryl group. The Schiff base ligands and their organotin(IV) complexes were tested for their in vitro antimicrobial and antioxidant activities to examine the biological outline of complexes in comparison to standard drugs. The results of activities data revealed that diorganotin(IV) complexes are more active than Schiff base ligands and some diorganotin(IV) complexes are even more active than the standard drugs. In all the synthesized complexes, compound 9 (Bu2SnL2) and 10 (Ph2SnL2) were most potent and can be used in future clinical trials.


Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3250 ◽  
Author(s):  
Yahya Toubi ◽  
Farid Abrigach ◽  
Smaail Radi ◽  
Faiza Souna ◽  
Abdelkader Hakkou ◽  
...  

Twelve new Schiff base derivatives have been prepared by the condensation reaction of different amino substituted compounds (aniline, pyridin-2-amine, o-toluidine, 2-nitrobenzenamine, 4-aminophenol, and 3-aminopropanol) and substituted aldehydes such as nicotinaldehyde, o,m,p-nitrobenzaldehyde, and picolinaldehyde in ethanol using acetic acid as a catalyst. The envisaged structures of the all the synthesized ligands have been confirmed on the basis of their spectral analysis FT-IR, mass spectroscopy, 1H- and 13C-NMR. In vitro screening of their antibacterial and antifungal potential against Escherichia coli bacterium and Fusarium oxysporum f.sp albedinis (F.o.a) fungus, respectively, revealed that all the ligands showed no significant antibacterial activity, whereas most of them displayed good antifungal activity. Homology modeling and docking analysis were performed to explain the antifungal effect of the most and least active compound against two F.o.a fungus proteins.


2020 ◽  
Vol 32 (7) ◽  
pp. 1768-1772
Author(s):  
Anita Rani ◽  
Manoj Kumar ◽  
Hardeep Singh Tuli ◽  
Zahoor Abbas ◽  
Vinit Prakash

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.


2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Peter Knauth ◽  
Gustavo J. Acevedo-Hernández ◽  
M. Eduardo Cano ◽  
Melesio Gutiérrez-Lomelí ◽  
Zaira López

Seven out of eight methanolic extracts from five plants native to Mexico were inactive against ten bacterial strains of clinical interest. The fruit extract of Chenopodium ambrosioides inhibited the bacteria Enterococcus faecalis (MIC = 4375 μg/ml), Escherichia coli (MIC = 1094 μg/ml), and Salmonella typhimurium (MIC = 137 μg/ml). The fruit extract of C. ambrosioides was with CC50 = 45 μg/ml most cytotoxic against the cell-line Caco-2, followed by the leaf extract from Pithecellobium dulce (CC50 = 126 μg/ml); interestingly, leaves of C. ambrosioides (CC50 = 563 μg/ml) and bark of P. dulce (CC50 = 347 μg/ml) extracts were much less cytotoxic. We describe for the first time the cytotoxic effect from extracts of the aerial parts and the flowers of Cirsium mexicanum (CC50 = 323 μg/ml and CC50 = 250 μg/ml, resp.). Phytochemical analysis demonstrated for both extracts high tannin and saponin and low flavonoid content, while terpenoids were found in the flowers. For the first time we report a cytotoxicological study on an extract of Eryngium carlinae (CC50 = 356 μg/ml) and likewise the bark extract from Amphipterygium adstringens (CC50 = 342 μg/ml). In conclusion the fruit extract of C. ambrosioides is a potential candidate for further biological studies.


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