Biological Activity of Triazolopyrimidine Copper(II) Complexes Modulated by an Auxiliary N-N-Chelating Heterocycle Ligands (original) (raw)
Related papers
Copper(II) Complexes with Mixed Heterocycle Ligands as Promising Antibacterial and Antitumor Species
Molecules
Complexes with mixed ligands [Cu(N-N)2(pmtp)](ClO4)2 ((1) N-N: 2,2′-bipyridine; (2) L: 1,10-phenanthroline and pmpt: 5-phenyl-7-methyl-1,2,4-triazolo[1,5-a]pyrimidine) were synthesized and structurally and biologically characterized. Compound (1) crystallizes into space group Pa and (2) in P-1. Both complexes display an intermediate stereochemistry between the two five-coordinated ones. The biological tests indicated that the two compounds exhibited superoxide scavenging capacity, intercalative DNA properties, and metallonuclease activity. Tests on various cell systems indicated that the two complexes neither interfere with the proliferation of Saccharomyces cerevisiae or BJ healthy skin cells, nor cause hemolysis in the active concentration range. Nevertheless, the compounds showed antibacterial potential, with complex (2) being significantly more active than complex (1) against all tested bacterial strains, both in planktonic and biofilm growth state. Both complexes exhibited a ve...
Molecules, 2022
In an attempt to increase the biological activity of the 1,2,4-triazolo[1,5-a]pyrimidine scaffold through complexation with essential metal ions, the complexes trans-[Cu(mptp)2Cl2] (1), [Zn(mptp)Cl2(DMSO)] (2) (mptp: 5-methyl-7-phenyl-1,2,4-triazolo[1,5-a]pyrimidine), [Cu2(dmtp)4Cl4]·2H2O (3) and [Zn(dmtp)2Cl2] (4) (dmtp: 5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine), were synthesized and characterized as new antiproliferative and antimicrobial species. Both complexes (1) and (2) crystallize in the P21/n monoclinic space group, with the tetrahedral surroundings generating a square-planar stereochemistry in the Cu(II) complex and a tetrahedral stereochemistry in the Zn(II) species. The mononuclear units are interconnected in a supramolecular network through π–π interactions between the pyrimidine moiety and the phenyl ring in (1) while supramolecular chains resulting from C-H∙∙∙π interactions were observed in (2). All complexes exhibit an antiproliferative effect against B16 tumor ce...
European journal of medicinal chemistry, 2009
Four mononuclear copper(II) complexes 1-4 have been synthesized with two new N-functionalized macrocyclic ligands L(1) and L(2). All complexes are well characterized by various spectroscopic techniques, elemental analyses and conductivity measurements. Results suggest that Cu(II) ion has N(2)O coordination from ligand and S(2) from two coordinated solvent molecules (SCH(3)CN for 1 and 3 while CH(3)OH for 2 and 4). The crystal structure of a representative complex 3 strengthen the proposed formulations for other isostructural copper(II) complexes. The structure of 3 shows few interesting features including rare bent mode of the coordinated CH(3)CN molecules. All complexes were assayed for in vitro antimicrobial activity against clinically isolated resistant strains of Pseudomonas aeruginosa and Proteus vulgaris; and standard strains of Staphylococcus aureus, P. aeruginosa, Klebsiella planticola and Escherichia coli. Results indicate that the copper complexes possess notable antimicro...
Molecular and cellular …, 2003
The coordination behaviour of the title ligand, 5-methyl-3-formylpyrazole N(4)-benzyl-N(4)-methylthiosemicarbazone (HMPz4BM), is reported with solid state isolation of copper(II) complexes, [Cu(HMPz4BM)X 2 ] (X = Cl, Br, NO 3 , ClO 4 and BF 4) which have been spectroscopically and structurally characterised. I.r. data for the free ligand and its Cu(II) complexes indicate that HMPz4BM exhibits a neutral NNS tridentate function via the pyrazolyl nitrogen(tertiary), azomethine nitrogen and thione sulphur. Electronic spectral data are suggestive of a square pyramidal environment for the seemingly pentacoordinated Cu(II) species. E.s.r parameters (RT and LNT) of the reported copper(II) complexes are indicative of a d x2-y2 ground state for the reported species. Cyclic voltammograms of Cu(II) complexes show a quasireversible Cu II /Cu III couple and also an irreversible Cu II /Cu I couple. X-ray crystallography of a representative species, [Cu(HMPz4BM)(NO 3) 2 ] (C2/c, monoclinic), has unambiguously documented the conjectural findings from i.r. data that coordinating sites of the title ligand are pyrazolyl (tertiary) nitrogen, azomethine nitrogen and the thione sulphur (NNS); and the oxygen of one of the nitrate ions has occupied the basal plane; the fifth coordination position has been occupied by the oxygen of another nitrate ion in a square pyramidal geometry. The antibacterial properties of the ligand and its copper(II) complexes studied on microorganism, Staphylococcus aureus have pointed out that most of the complexes have higher activities than that of the free ligand.
Inorganica Chimica Acta, 2007
Synthesis and characterization of six new complexes [Cu{2,6-(MeO) 2 nic} 2 (H 2 O)] 2 (1), [Cu{2,6-(MeO) 2 nic} 2 (H 2 O)] 2 AE 3DMF (2), where 2,6-(MeO) 2 nic is 2,6-dimethoxynicotinate and DMF is N,N-dimethylformamide, [Cu(3-pyacr) 2 (H 2 O) 2 ] n (3), where 3-pyacr is trans-3-(3-pyridyl)acrylate, [Cu(en) 2 (H 2 O) 2 ]X 2 , where X is 2,6-(MeO) 2 nic (4) or 3-pyacr (5) and en is ethylenediamine, and [Cu(3pyacr) 2 (dien)(l-H 2 O) 0.5 ] 2 AE 7H 2 O (6), where dien is diethylenetriamine are reported. The characterizations were based on elemental analysis, infrared, electronic and EPR spectra, and magnetic measurements over a temperature range of 1.8-300 K. Crystal structures of complexes 2, 4 and 6 have been determined by X-ray single crystal structure analysis. The available evidence supports dimeric structure of the acetate type for 1 and 2. Crystal structure of polymeric complex 3 has been determined from X-ray powder diffraction data. The 3pyacr anions in pairs form bridges between two octahedrally surrounded copper(II) atoms in such a way that one 3-pyacr is coordinated to the first Cu II by an oxygen atom of its carboxyl group and to the second Cu II by the nitrogen atom of its pyridine ring, while the other is coordinated to the same two Cu II atoms in a similar way, but the other way round. Environment about the copper(II) atom for 4 and 5 is a square bipyramid (4+2).
Polyhedron, 2000
The reaction of an ethanolic solution of copper(II) pyridinecarboxylates CuX 2 ·nH 2 O (where X is nicotinate (nic) (n=0) or isonicotinate (isonic) (n= 4)) with ethylenediamine (en) in a molar ratio of 1:2 lead to the isolation of solid tetragonally distorted octahedral complexes of the type [Cu(en) 2 (H 2 O) 2 ]X 2 ·nH 2 O (n= 1 for nic; n=0 for isonic). The analogous reaction of CuX 2 ·nH 2 O with diethylenetriamine (dien) in a molar ratio of 1:1 leads to the formation of square-pyramidal pentacoordinated complexes of the type [CuX(dien)(H 2 O)]X. On the other hand, the reaction of equimolar quantities of copper(II) nitrate and dien with nicotinate anions (equimolar quantities of pyridinecarboxylic acid and NaOH) in ethanolic solutions gives a solid monomeric complex [Cu(nic)(NO 3 )dien)(H 2 O)]·H 2 O in which the coordination polyhedron around the Cu(II) atom is a (4+1 + 1) distorted tetragonal bipyramid. Based on the molecular structure the electronic and IR spectra are discussed. Moreover, the results of the quantitative determination of antimicrobial activity of the isonic complexes [Cu(isonic) 2 (H 2 O) 4 ], [Cu(en) 2 (H 2 O) 2 ](isonic) 2 , [Cu(isonic)(dien)(H 2 O)](isonic), as well as isonicotinic acid, ethylenediamine and diethylenetriamine alone are discussed.
Inorganics
For the first time, a thiosemicarbazone-type ligand containing a paracetamol structural unit was synthesized. Five new coordination compounds based on copper(II) salts: [Cu(L)CH3COO] (1), [{Cu(L)Cl}2]·H2O (2), [Cu(L)H2O·DMF]NO3 (3), [Cu(L)Br] (4), [Cu(L)H2O]ClO4 (5), were obtained, where HL is N-[4-({2-[1-(pyridin-2-yl)ethylidene]hydrazinecarbothioyl}amino)phenyl]acetamide. The new HL was characterized by NMR, FTIR, spectroscopy, and X-ray crystallography. All copper(II) coordination compounds were characterized by elemental analysis, FTIR, EPR spectroscopy, and molar electrical conductivity. Furthermore, single crystal X-ray diffraction analysis elucidated the structures of thiosemicarbazone HL as well as complexes 1–3. All compounds were tested for antimicrobial, antifungal, and antioxidant activities, and their toxicity to Daphnia magna was studied. Biological evaluation has revealed that most of the synthesized compounds demonstrate promising antibacterial, antifungal, and antio...
Polyhedron, 2009
A novel bridged binuclear Cu(II) complex with mixed ligands, di-μ-(2-aminopyridine(N,N′))-bis[(2,6-pyridinedicarboxylate)aquacopper(II)] tetrahydrate, formulated as [Cu(μ-ap)(dipic)(H2O)]2·4H2O (1) (dipic = 2,6-pyridinedicarboxylate, ap = 2-aminopyridine), has been synthesized and characterized by elemental, spectral (IR and UV–Vis.), thermal analysis, magnetic measurements and single crystal X-ray diffraction analysis. The central Cu(II) ion resides on a centre of symmetry in a distorted square-pyramid coordination environment comprising of two N atoms, one from dipic and one from the ap ring, two carboxylate O atoms from dipic, and one O atom from water. Intermolecular N–H⋯O and O–H⋯O hydrogen bonds and π–π stacking interactions seem to be effective in the stabilization of the crystal structure. The free ligands and the complex were also evaluated for their antimicrobial and radical scavenging activities (DPPH = 1,1-diphenyl-2-picrylhydrazyl hydrate) using in vitro microdilution methods. Antimicrobial screening of the free ligands and their complex showed that the free ligands and the complex possess antifungal activity against Candida sp.
Biological evaluation of copper(II) complex with nalidixic acid and 2,2′-bipyridine (bpy)
Inorganica Chimica Acta, 2019
A copper(II) complex with the first antibacterial quinolone drug nalidixic acid (=nal) has been synthesized and characterized in the presence of N−donor heterocyclic ligand 2,2'-bipyridyl (=bpy). The molecular structure of the complex reveals a distorted square pyramidal based geometry in Cu(II) atom which is confirmed by the X-ray crystallography technique. Study of the antibacterial activity showed that the complex exhibited promising antibacterial activity against both Escherichia coli and Staphylococcus aureus. The binding affinity of the complex towards calf thymus DNA (CT DNA) has been investigated by electronic absorption, circular dichroism and fluorescence spectroscopy techniques. The binding results revealed an intercalation binding mode of the complex with CT DNA. This complex has a superior ability to quench the intrinsic fluorescence of both HSA and BSA proteins via a static quenching LUMO HOMO Cancer cells Molecular Docking mode and it has been observed at two different temperatures (30 and 40 C). Molecular docking analysis reveals that the interaction of the complex with proteins was stabilized by hydrogen bonding and hydrophobic interaction. Furthermore, the complex was subjected to cytotoxicity tests against human breast cancer cell lines (MCF-7) and showed potential cytotoxicity with IC50 value of 79.05 μM.
Asian Journal of Chemistry, 2020
Two new copper(II) complexes of pyridine-2-carboxaldehyde-N-(2-pyridyl)hydrazone [Cu(PCPH)(H2O)2](NO3)(H2O)2 (1) and 2-hydroxy-1-naphthaldehyde-semicarbazone [Cu(II)(HNSC)H2O]·NO3·H2O (2) have been synthesized and characterized by spectroscopic techniques and single crystal X-ray diffraction study. Complex 1 crystallized as square pyramidal coordination complex in triclinic crystal system while complex 2 crystallized as square planar complex in monoclinic crystal system. EPR spectral patterns are of normal order of energy levels, i.e. x2-y2 >> z2 > xy > xz, yz, with partial covalent character. Both copper(II) complexes were found to be groove binding to calf-thymus DNA and showed activity against E. coli, S. aureus, B. cereus and E. faccium.