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Synthesis, characterization, DNA interaction and antimicrobial screening of isatin-based polypyridyl mixed-ligand Cu(II) and Zn(II) complexes  [PDF]
NATARAJAN RAMAN,SIVASANGU SOBHA
Journal of the Serbian Chemical Society , 2010,
Abstract: Several mixed ligand Cu(II)/Zn(II) complexes using 3-(phenyl-imino)-1,3-dihydro-2H-indol-2-one (obtained by the condensation of isatin and aniline) as the primary ligand and 1,10-phenanthroline (phen)/2,2’-bipyridine (bpy) as an additional ligand were synthesized and characterized analytically and spectroscopically by elemental analyses, magnetic susceptibility and molar conductance measurements, as well as by UV–Vis, IR, NMR and FAB mass spectroscopy. The interaction of the complexes with calf thymus (CT) DNA was studied using absorption spectra, cyclic voltammetric and viscosity measurements. They exhibit absorption hypochromicity, and the specific viscosity increased during the binding of the complexes to calf thymus DNA. The shifts in the oxidation–reduction potential and changes in peak current on addition of DNA were shown by CV measurements. The Cu(II)/Zn(II) complexes were found to promote cleavage of pUC19 DNA from the supercoiled form I to the open circular form II and linear form III. The complexes show enhanced antifungal and antibacterial activities compared with the free ligand.
Synthesis, Physico-Chemical and Antimicrobial Properties of Co(II), Ni(II), and Cu(II) Mixed-Ligand Complexes of Dimethylglyoxime
A.A. Osunlaja,N.P. Ndahi,J.A Ameh,A. Adetoro
Research Journal of Applied Sciences, Engineering and Technology , 2011,
Abstract: The synthesis of non-electrolyte mixed-ligand complexes of the general formula [M(Hdmg)B], where M = Co(II), Ni(II) or Cu(II) Hdmg = dimethylglyoximato monoanion, B = 2- aminophenol(2-aph), diethylamine (dea) or malonic acid (MOH) are described. Metal analysis, melting points, solubility, conductivity, IR and UV/Visible electronic spectra were used in determining their physico-chemical properties. The antimicrobial activities of the complexes were tested against Esherichia coli, Staphylococcus aureus, Aspergillus niger and Aspergillus flavus. The complexes melted/decomposed at 120-306oC and, most of them dissolved only in polar solvents. The colours of the complexes are mostly dark - brown or red. The spectral results suggest the binding of Hdmg, 2-amino phenol or malonic acid through the N atom and O atoms respectively to the metal ion In the electronic spectra of the complexes, the absorption bands observed in the UV/Visible region are presumed to be either due to charge transfer or intra-ligand transitions from the ligands or d-d transitions from the metal ions. The complexes showed marked antimicrobial activity against the tested microbes at 10 mg/mL. The possible use of the complexes as chemotherapeutic agents is hereby suggested.
Microwave synthesis, spectral, thermal and antimicrobial activities of Co(II), Ni(II) and Cu(II) metal complexes with Schiff base ligand
Anand Prakash Mishra,Hershita Purwar,Rajendra Kumar Jain
Biointerface Research in Applied Chemistry , 2012,
Abstract: The complexes of tailor made ligands with life essential metal ions may be an emerging area to answer the problems of multi drug resistance (MDR). Some novel Schiff base metal complexes of Co(II), Ni(II) and Cu(II) derived from 4-chlorobenzylidene-2,6-dichloro-4-nitroaniline (CDN) have been synthesized by conventional as well as microwave methods. These compounds have been characterized by elemental analysis, FT-IR, FAB-mass, molar conductance, electronic spectra, ESR, magnetic susceptibility, and thermal analysis. The complexes are coloured and stable in air. Analytical data revealed that all the complexes exhibited 1:2 (metal: ligand) ratio with coordination number 4. FAB-mass and thermal data show degradation pattern of the complexes. The crystal system, lattice parameter, unit cell volume and number of molecules in unit cell in the lattice of complexes have been determined by XRD analysis. XRD patterns indicate crystalline nature for the complexes. The Schiff base and metal complexes show a good activity against the bacteria; E. coli, S. aureus, S. fecalis and fungi A.niger, T. polysporum, C. albicans. The antimicrobial results also indicate that the metal complexes are better antimicrobial agents as compared to the Schiff base.
SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL STUDIES ON MIXED LIGAND COMPLEXES OF CO (II), NI (II) AND CU (II) WITH ISOXAZOLE SCHIFF BASE AND 1, 10-PHENANTHROLINE/ 2, 2' -BIPYRIDINE LIGANDS Synthese, Charakterisierung und antimikrobiellen STUDIES ON MIXED Ligand-Komplexe von Co (II), Ni (II) und Cu (II) MIT Isoxazol SCHIFF BASE AND 1, 10-Phenanthrolin / 2, 2 '-Bipyridin-Liganden
R.Shakru, N.J.P.Subhashini, Shivaraj
Heterocyclic Letters , 2011,
Abstract: Synthesis, Characterization and antimicrobial studies of Cobalt (II), Nickel (II) and Copper (II) ternary complexes of mixed ligands with Schiff base derived from 3-amino 5-methyl isoxazole with 2-hydroxy 1-naphthaldehyde and 1, 10-phenanthroline/ 2, 2' bipyridine. The micro analytical, magnetic moment, IR and electronic spectral data analysis have been used to confirm the structure of these complexes, their lower electrical conductance values indicates that all the complexes are non- electrolytes. The magnetic moment values and electronics spectral data of the Co (II) and Ni (II) complexes further indicates the octahedral geometry and Cu (II) complexes are tetragonal geometry. The synthesized compounds have been tested against microorganisms such as (bacillus and pseudomonas) bacteria and (R.Saloni and A. niger) fungi. A comparative study of the MIC (minimum inhibitory concentration) values of the ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligand and control.
Cu(II), Ni(II), and Zn(II) Complexes of Salan-Type Ligand Containing Ester Groups: Synthesis, Characterization, Electrochemical Properties, and In Vitro Biological Activities  [PDF]
P. Jeslin Kanaga Inba,B. Annaraj,S. Thalamuthu,M. A. Neelakantan
Bioinorganic Chemistry and Applications , 2013, DOI: 10.1155/2013/439848
Abstract: A salen ligand on reduction and N-alkylation affords a novel [N2O2] chelating ligand containing ester groups [L = diethyl-2, -(propane-1,3-diylbis((2-hydroxy-3-methoxy benzyl)azanediyl))diacetate]. The purity of the ligand was confirmed by NMR and HPLC chromatograms. Its Cu(II), Ni(II), and Zn(II) complexes were synthesized and characterized by a combination of elemental analysis, IR, NMR, UV-Vis, and mass spectral data, and thermogravimetric analysis (TG/DTA). The magnetic moments, UV-Vis, and EPR spectral studies support square planar geometry around the Cu(II) and Ni(II) ions. A tetrahedral geometry is observed in four-coordinate zinc with bulky N-alkylated salan ligand. The redox properties of the copper complex were examined in DMSO by cyclic voltammetry. The voltammograms show quasireversible process. The interaction of metal complexes with CT DNA was investigated by UV-Vis absorption titration, ethidium bromide displacement assay, cyclic voltammetry methods, and agarose gel electrophoresis. The apparent binding constant values suggest moderate intercalative binding modes between the complexes and DNA. The in vitro antioxidant and antimicrobial potentials of the synthesized compounds were also determined. 1. Introduction Salen metal complexes are the interest of many workers because of their applications in food industry, in the treatment of cancer [1], as antibactericide agents [2, 3], as antivirus agents [4], as fungicide agents [5], and for other biological properties [6]. The antitumor activity of salen complex arises due to its DNA binding properties. The salen complexes are conformationally flexible and adopt a variety of geometries. Also, salen metal complexes have a unique flat electron-rich aromatic surface that may facilitate their interactions with nucleic acids. Hydroxyl groups in the salen complexes act as a quinone system which would cooperate to facilitate the formation of free radicals responsible for DNA cleavage [7]. The biological properties of salen complexes are enhanced by functionalization with a variety of substituents [8–11]. When salen compounds are reduced at the imine function, the more flexible, reduced salen derivatives (salan) are obtained. Considerable attention has been devoted to the preparation and structural characterization of metal complexes containing salen-type ligands. However, little attention has been paid to systems in which functionalized salan is used as ligands. In the present investigation N-alkylated salan complexes are used for DNA binding and antimicrobial and antioxidant properties. In
Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) Mixed Ligand Complexes of Theophylline and Cyanate: Synthesis and Spectroscopic Characterization  [cached]
Shayma Ahmed Shaker
Modern Applied Science , 2009, DOI: 10.5539/mas.v3n12p88
Abstract: New mixed ligand complexes were synthesized between theophylline and cyanate to give complexes with general formula [M(Tp)4Y2] where Tp= theophylline, Y= cyanate ion and M=Co(II), Ni(II),Cu(II), Zn(II) and Cd(II). The resulting products were found to be crystallined which have been characterized using UV-Visible spectroscopic properties and Infrared spectra. Elemental analyses were performed using (C, H, N) and atomic absorption technique. The magnetic susceptibility and the conductivity for the complexes were also measured. The present results suggested the octahedral configuration for the metal complexes.
Synthesis, Characterization and Antimicrobial Studies of Co(II), Ni(II), Cu(II) and Zn(II) Complexes of (E)-2-(4-Dimethylbenzydimino)-Glycylglycine, (Glygly-DAB) a Schiff Base Derived from 4-Dimethylaminobenzaldehyde and Glycylglycine  [PDF]
Maurice Kuate, Mariam Asseng Conde, Katia N. Nchimi, Awawou G. Paboudam, Sally-Judith E. Ntum, Peter T. Ndifon
International Journal of Organic Chemistry (IJOC) , 2018, DOI: 10.4236/ijoc.2018.83022
Abstract: A tridentate Schiff base ligand, (E)-2-(4-dimethylbenzydimino) glycylglycine (glygly-DAB), derived from the condensation of 4-Dimethylaminobenzaldehyde (DAB) and glycylglycine (glygly) together with its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been synthesized and characterized using various physico-chemical methods including C,H,N elemental analysis, melting point determination, molar conductivity measurement, IR, 1H NMR and UV-Vis. The ligand and metal complexes were screened in vitro for antimicrobial and antifungal activities on four bacterial strains (Staphylococcus aureus, Escherichia coli, Salmonella thyphi and Pseudomonas aeruginosa) and two fungal strains (Candida albicans and Cryptococcus neoformans). glygly-DAB showed remarkable antifungal activities on all the fungal strains and antibacterial activities on one bacterial strain.
Spectroscopic, Thermal, and Antimicrobial Studies of Co(II), Ni(II), Cu(II), and Zn(II) Complexes Derived from Bidentate Ligands Containing N and S Donor Atoms  [PDF]
Kiran Singh,Yogender Kumar,Parvesh Puri,Gulab Singh
Bioinorganic Chemistry and Applications , 2012, DOI: 10.1155/2012/729708
Abstract: Two new heterocyclic Schiff bases of 4-amino-5-mercapto-3-H/propyl-1,2,4-triazole and 5-nitrofurfuraldehyde [ ] and their cobalt, nickel, copper, and zinc complexes have been synthesized and characterized by elemental analyses, spectral (UV-Vis, IR, 1H NMR, Fluorescence, and ESR) studies, thermal techniques, and magnetic moment measurements. The heterocyclic Schiff bases act as bidentate ligands and coordinate with metal ions through nitrogen and sulphur of the thiol group. The low molar conductance values in DMF indicate that the metal complexes are nonelectrolytes. The magnetic moments and electronic spectral data suggest octahedral geometry for the Co(II), Ni(II), and Zn(II) complexes and square planar for Cu(II) complexes. Two Gram-positive bacteria (Staphylococcus aureus MTCC 96 and Bacillus subtilis MTCC 121), two Gram-negative bacteria (Escherichia coli MTCC 1652 and Pseudomonas aeruginosa MTCC 741), and one yeast, Candida albicans, were used for the evaluation of antimicrobial activity of the newly synthesized compounds. 1. Introduction Recently, for the rapid development of drug resistance, new antimicrobial agent should be designed and synthesized with chemical characteristics clearly different from those of existing ones. 1,2,4-triazoles and their fused heterocyclic derivatives have received considerable attention owing to their synthetic and effective biological importance such as analgesic [1], antitumor [2], anticancer [3, 4], antimicrobial [5–7], anticonvulsant [8, 9], and antiproliferative activities [10]. In addition, 1,2,4-triazole and, in particular, its derivatives exhibit a strong property of acting as a bridging ligand between two metal centers [11] and can provide 1,2-bridiging as well as 2,4-bridiging form in case of 4-unsubstituted 1,2,4-triazoles. Schiff bases represent an important class of compounds because they are utilized as starting materials in the synthesis of industrial products [12]. Schiff bases derived from 3-substituted-4-amino-5-mercapto-1,2,4-triazoles show analgesic, antimicrobial, anti-inflammatory, and antidepressant activities [13]. When bioorganic molecules or drugs are bound to metal ions, there is a drastic change in their biomimetic properties, therapeutic effects, and pharmacological properties. Metal complexes of Schiff bases derived from triazoles have been synthesized, and it has been observed that antimicrobial activity of the Schiff bases is significantly enhanced when coordinated to metal ions [14, 15]. The metal complexes containing substituted 1,2,4-triazole ligands have spin-crossover properties
COBALT(II), Ni(II), Cu(II), Zn(II), CD(II), Hg(II), U0(2)(VI) AND th(IV) COMPLEXES FROM ONNN SCHIFF BASE LIGAND
REDDY. K,RAMA KRISHNA; SUNEETHA,P; KARIGAR,C. S; MANJUNATH,N. H; MAHENDRA,K. N;
Journal of the Chilean Chemical Society , 2008, DOI: 10.4067/S0717-97072008000400003
Abstract: a new tetradentate schiff base, 3-[(z)-2-piperazin-l-yl-ethylimino]-l, 3-dihydro indol-2-one was synthesized by the condensation of isatin(indole-2,3-dione) with l-(2-aminoethyl)piperazine(aep). its complexes with co(ii), ni(ii), cu(ii), zn(ii), cd(ii), hg(ii), u02(vi) and th(iv) have been synthesized and characterized by microanalysis, conductivity, uv-visible, ft-ir, 'h nmr, tga and magnetic susceptibility measurements. the complexes have 1:1 metal to ligand stoichiometry. the complexes of cu(ii) and th(iv) are 1:1 electrolytes whereas the complexes of co(ii), ni(ii), zn(ii), cd(ii), hg(ii) and u02(vi) are nonelectrolytes. itie spectral data revealed that the ligand acts as a neutral tetradentate, coordinating through the azomethine nitrogen, two piperazine nitrogen atoms and carbonyl oxygen. octahedral geometry for co(ii), ni(ii), cu(ii), zn(ii), cd(ii) and hg(ii) complexes and a coordination number of 8 for u02(vi) and th(iv) complexes are proposed. the ligand and its metal complexes were screened for antibacterial activity against bacillus subtilis, staphylococcus aureus (s. aureus), escherichia coli (e. coli) and pseudomonas aeruginosa and the complexes are more potent bactericides than the ligand. the anthelmentic activity of the ligand and its complexes against earthworms was also tested.
COBALT(II), Ni(II), Cu(II), Zn(II), CD(II), Hg(II), U0(2)(VI) AND th(IV) COMPLEXES FROM ONNN SCHIFF BASE LIGAND  [cached]
RAMA KRISHNA REDDY. K,P SUNEETHA,C. S KARIGAR,N. H MANJUNATH
Journal of the Chilean Chemical Society , 2008,
Abstract: A new tetradentate Schiff base, 3-[(Z)-2-piperazin-l-yl-ethylimino]-l, 3-dihydro indol-2-one was synthesized by the condensation of isatin(Indole-2,3-dione) with l-(2-aminoethyl)piperazine(AEP). Its complexes with Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), U0(2)(VI) and Th(IV) have been synthesized and characterized by microanalysis, conductivity, UV-visible, FT-IR, 'H NMR, TGA and magnetic susceptibility measurements. The complexes have 1:1 metal to ligand stoichiometry. The complexes of Cu(II) and Th(IV) are 1:1 electrolytes whereas the complexes of Co(II), Ni(II), Zn(II), Cd(II), Hg(II) and U0(2)(VI) are nonelectrolytes. ITie spectral data revealed that the ligand acts as a neutral tetradentate, coordinating through the azomethine nitrogen, two piperazine nitrogen atoms and carbonyl oxygen. Octahedral geometry for Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II) complexes and a coordination number of 8 for U0(2)(VI) and Th(IV) complexes are proposed. The ligand and its metal complexes were screened for antibacterial activity against Bacillus subtilis, Staphylococcus aureus (S. aureus), Escherichia Coli (E. Coli) and Pseudomonas aeruginosa and the complexes are more potent bactericides than the ligand. The anthelmentic activity of the ligand and its complexes against earthworms was also tested.
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