Antimicrobial Activity Of Copper Research Articles

Synthesis, structural studies and antimicrobial activity of copper(II) complexes derived from 2,4-difluoro-6-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol

Reaction of the Schiff base 2,4-difluoro-6-(((2-(pyrrolidin-1-yl)ethyl)imino)methyl)phenol (HL) with copper salts and some bridging ligands afforded five complexes, [CuClL] (1), [Cu(μ-Br)L]n (2), [Cu(μ-Br)(μ1,5-dca)L]n·nCH3OH (3), [Cu(μ1,3,5-dca)L]n (4) and [Cu(μ1,3-N3)L]n (5) (dca = dicyanoamide). These complexes have been analyzed and characterized by the means of elemental analysis, infrared and electronic spectra, as well as single crystal X-ray diffraction. The Cu atom in the mononuclear complex 1 is in square planar coordination, in the bromido-bridged polynuclear complex 2 is in square pyramidal coordination, in the bromido and dca co-bridged polynuclear complex 3 is in square pyramidal coordination, in the dca bridged polynuclear complex 4 is in octahedral coordination, and in the azido bridged polynuclear complex 5 is in square pyramidal coordination. The Schiff base ligand coordinates to the CuII ions through the phenolate oxygen, imine nitrogen and pyrrolidine nitrogen atoms. The biological study revealed that the complexes have good antimicrobial activity against the bacteria strains B. subtilis, S. aureus, E. coli and P. fluorescens.

Synthesis, Physicochemical, and Antimicrobial Activity of Copper and Zinc Complexes with N, O - Bidentate Schiff Base

This paper is intended to prepare new antimicrobial complexes with proven efficiency. The Schiff base, through the condensation process of salicylaldehyde and p-toludine, and its Cu and Zn complexes were successfully synthesized. The Schiff base and its complexes were characterized using molar conductivity, Ultraviolet-visible (UV-Vis), atomic absorption spectroscopy (AAS), and Fourier transform infrared (FTIR) techniques. Accordingly, these characterizations not only confirmed that the synthesized Schiff base acted as N,O bidentate ligand (through azomethine nitrogen and phenoxide oxygen) and chelated with Cu(II) and Zn(II) in the metal-to-ligand ratio of 1:2 but also revealed the characteristic electronic-transition of π→π*/n→π* of the ligand, and ligand-metal charge transfer and d-d of the metal complexes. Moreover, both Cu and Zn complexes recorded weak molar conductance of 54.12 and 51.41 S cm2 mol-1, respectively. Further, their antibacterial activities were evaluated by disc diffusion assay against Staphylococcus aureus (gram-positive), Escherichia coli (gram-negative), and Bacillus cereus (gram-negative) bacteria. For all microbial, the metal complexes recorded higher activities than the parent ligand; such increased activity of the complexes may be due to the chelation of the metal ion in the complexes, which enhances the lipophylic character favoring its permeation through the lipid layer of the cell membrane. Such metal complexes can therefore be explored in the future as an option for decreasing the pathogenic potential of infecting bacteria.

Syntheses, Characterization, Crystal Structures and Antimicrobial Activity of Copper(II), Nickel(II) and Zinc(II) Complexes Derived from 5-Bromo-2- ((cychlopentylimino)methyl)phenol

Four new complexes of copper(II), nickel(II) and zinc(II), [CuL2] (1), [Ni3L2(4-BrSal)2(CH3COO)2(CH3OH)2]·2CH3OH (2), [ZnBr2(HL)2] (3) and [ZnL(dca)]n (4), where L is 5-bromo-2-(cychlopentylimino)methyl)phenolate, HL is the zwitterionic form of 5-bromo-2-((cychlopentylimino)methyl)phenol, 4-BrSal is the monoanionic form of 4-bromosalicylaldehyde, dca is dicyanamide anion, were synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopy. The structures of the complexes were further confirmed by single crystal X-ray structure determination. Complex 1 is a mononuclear copper(II) compound, with a crystallographic two-fold rotation axis symmetry. The Cu atom is in distorted square planar coordination. Complex 2 is a trinuclear nickel(II) compound, with an inversion center symmetry. The Ni atoms are in octahedral coordination. Complex 3 is a mononuclear zinc(II) compound, while complex 4 is a dca bridged polymeric zinc(II) compound. The Zn atoms are in tetrahedral coordination. The compounds were assayed for their antimicrobial activities.

Syntheses, Characterization, Crystal Structures and Antimicrobial Activity of Copper(II), Nickel(II) and Zinc(II) Complexes Derived from 5-Bromo-2-((cychlopentylimino)methyl)phenol.

Four new complexes of copper(II), nickel(II) and zinc(II), [CuL2] (1), [Ni3L2(4-BrSal)2(CH3COO)2(CH3OH)2]·2CH3OH (2), [ZnBr2(HL)2] (3) and [ZnL(dca)]n (4), where L is 5-bromo-2-((cychlopentylimino)methyl)phenolate, HL is the zwitterionic form of 5-bromo-2-((cychlopentylimino)methyl)phenol, 4-BrSal is the monoanionic form of 4-bromosalicylaldehyde, dca is dicyanamide anion, were synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopy. The structures of the complexes were further confirmed by single crystal X-ray structure determination. Complex 1 is a mononuclear copper(II) compound, with a crystallographic two-fold rotation axis symmetry. The Cu atom is in distorted square planar coordination. Complex 2 is a trinuclear nickel(II) compound, with an inversion center symmetry. The Ni atoms are in octahedral coordination. Complex 3 is a mononuclear zinc(II) compound, while complex 4 is a dca bridged polymeric zinc(II) compound. The Zn atoms are in tetrahedral coordination. The compounds were assayed for their antimicrobial activities.

Synthesis and Antimicrobial Activity of Copper and Zinc Complexes based on Benzimidazole scaffold

Synthesis and Antimicrobial Activity of Copper and Zinc Complexes based on Benzimidazole scaffold

Biocompatibility and antimicrobial activity of copper(II) oxide hybridized with nano silicate platelets

Nano-sized copper(II) oxide (CuO) is an interesting material with proficient antibacterial activities but limited due to its toxicity to mammalian cells. In this study, CuO nano-sized needles were coated on the surface of nano-silicate platelets (NSP), which were exfoliated from natural montmorillonite clays and with the thickness of about 1 nm, to form nanohybrids. Our findings indicate that NSPs can effectively prevent the aggregation of CuO needles, and significantly enhance antibacterial efficiency without affecting biocompatibility. An optimal antibacterial activity against Staphylococcus aureus exceeding 99% could be obtained, while that for Escherichia coli was about 88%. Electron paramagnetic resonance results suggest that •OH radicals, one of the reactive oxygen species generated by CuO/NSP, might damage the cellular components and thus result in the death of bacterial.

Antimicrobial activity of copper and silver metal nanoparticles synthesized from Riccia fluitans

Riccia bryophyte, a genus of liverworts that comes under the family of Ricciaceae, order Marchantiales. The plants are primitive plant structure, that's not differentiated into root, stem, and leaf. The material utilized in this study was a Spp of a Riccia fluitans, that grows on damp soil or, less unremarkably, floating in ponds, and is usually utilized in aquariums. The nanoparticles utilized in this study exhibit potential medicinal drug activity. Advantages of its therapeutic potential can be utilized in a sizable number of fields like health care, cosmetics, biomedical, food and feed, drug-gene delivery, surroundings, health mechanics, optics, chemical industries, physical science, area industries, energy science, catalysis, lightweight emitters, single lepton transistors, nonlinear optical devices, and photo-electrochemical applications. This study aimed to gauge the medicinal drug activity of Riccian nanoparticles, copper-loaded nanoparticles, and silver-loaded nanoparticles against varied microorganisms. The result of the study showed that the Nanoparticle, Ag-NP and Cu-Np synthesized from Riccia is having good antimicrobial activity against tested organisms.

Antimicrobial activity of copper and silver metal nanoparticles synthesized from Riccia fluitans

Antimicrobial activity of copper and silver metal nanoparticles synthesized from Riccia fluitans

Synthesis, Characterization, Swiss ADME and Antimicrobial Activity of Copper (II) Complex with 2-Sulfanilamidopyrimidine: Through DFT Spectroscopic with Profound Biological Implications

Sulphadiazine and their copper metal complexes are dexterous ligands, which are condensation products of primary amines with carbonyl compounds gaining importance day by day in the present scenario. Spectral characterization and examination of the potential antimicrobial and antioxidant activity of the synthesized complex were performed. The imine Cu(II) complex is characterized by FTIR and UV/Vis spectroscopy. The Stoichiometric M:L ratio was determined by Joe and Jones method. These compounds and their copper metal complex are very important in various biological systems and their medicinal and pharmaceutical fields. Schiff foundations show beneficial natural functions such as anti-inflammatory, analgesic, antimicrobial, anticonvulsant, antitubercular, anticancer, antioxidant, anthelmintic, and antiglycation. The present review summarizes information on the diverse biological activities and also highlights the recently synthesized numerous Schiff bases and their metal complex as potential bioactive core.

Synthesis, characterization and antimicrobial activity of copper(II) Schiff base adducts of some p-substituted aniline Schiff bases

The synthesis, characterization and antimicrobial activity of Cu(II) complexes of some p-substituted aniline Schiff base ligands have been carried out. The Schiff bases were obtained from salicylaldehyde and o-vanillin. The Cu(II) complexes have been characterized by elemental analysis, conductivity measurement, infrared and electronic spectral data. The complexes were obtained either as metal chelates [Cu(L)2] or Schiff base adducts (CuCl2.2LH).xH2O. The metal chelates were non-electrolytes while the Schiff base adducts exhibited 1:1 or 2:1 electrolytes in methanol. The Cu(II) complexes exhibited slight antimicrobial activity against Escherichia coli ATCC® 8739™*, Staphylococcus aureus subsp. aureus ATCC® 6538™*, Bacillus subtilis subsp. spizizenii ATCC® 6633™* and Candida albicans ATCC® 2091™*. The complexes exhibited significant antifungal activity.
 
 KEY WORDS: Metal Chelates, Schiff bases, Adducts, Cu(II) complexes, Salicylaldimines
 
 Bull. Chem. Soc. Ethiop. 2021, 35(1), 33-42.
 DOI: https://dx.doi.org/10.4314/bcse.v35i1.3

Synthesis, characterization, molecular docking and antimicrobial activity of copper(II) complexes of metronidazole and 1,10 phenanthroline

Three new compounds containing mono- and dinuclear Cu(II) complexes, [Cu(Met)2Cl2]2, Cu(H2O)(Met)2Cl]2 and [Cu(H2O)(phen)2]NO3 (Met = metronidazole; Phen = 1,10-phenathroline) have been synthesized and characterized by Infra-Red, UV–Vis, Single Crystal X-ray analyses, Thermogravimetric techniques and Scanning electron micrography. The biological activities of the complexes were evaluated against a series of Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii); Gram-positive (Enterococcus faecium, Bacillus cereus and Staphylococcus aureus) strains as well as the yeasts (Candida albicans and Cryptococcus neoformans). Density-functional theory (DFT) studies revealed that compound [Cu(Met)2Cl2]2 is less stable in comparison to compounds, [Cu(H2O)(phen)2]NO3 and [Cu(H2O)(Met)2Cl]2. Docking studies of Cu(II) complexes with DNA structure (PDB id 1ZEW) found drug activity by groove binding. Binding mode of Cu(II) complexes with (i) fungal cytochrome P450 sterol 14α-demethylase (CYP51), which facilitates the synthesis of ergosterol in fungi; (ii) 4HL2; a New Delhi metallo-β-lactamase-1 (NDM-1) produced by strains of K. pneumoniae and (iii) 4M7U; an enzyme dihydrofolate reductase (DHFR) responsible for E. faecium activity and bacterial growth was established via docking studies. In general, [Cu(Met)2Cl2]2 was the most broad-spectrum antimicrobial compound, indicating an important role of electron-withdrawing substituents such as chlorine and suggest their potential application as antibacterial agents. The findings should be helpful in the development of antimicrobial drugs of Cu(II) complexes of metronidazole and 1,10 phenanthroline.

Synthesis, crystal structures, and antimicrobial activity of copper(II) complexes derived from N′-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide

Two mononuclear copper(II) compounds, [Cu(HL)2](ClO4)2 · (H2L)ClO4 · 3H2O (1) and [CuL2] (2), where L is the monoanionic form of N′-(1-(pyridin-2-yl)ethylidene)isonicotinohydrazide (HL), have been prepared and characterized by elemental analyses, IR, and single crystal X-ray crystallographic determination. Compound 1 contains a [Cu(HL)2]2+ complex cation, a H2L+ cation, three perchlorate anions, and three water molecules of crystallization. Compound 2 contains one neutral [CuL2] complex molecule. The Cu atoms in the complexes are in octahedral coordination, with the hydrazone ligands coordinate to the Cu atoms through the pyridine N, imine N, and enolate O atoms. The effect of the compounds on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.

Antimicrobial Activity of Copper(II) and Cobalt(II) Complexes of Citral-Valine Derived Schiff Base

In present work, the screening of antimicrobial activities of copper(II) and cobalt(II) complexes with Schiff base ligand derived from the condensation of citral with valine (amino acid) was carried out on agar plates are reported. The antibacterial activity of Schiff base and its copper(II) and cobalt(II) complexes were evaluated against two bacterial strains Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative) and fungus Candida albicans. The results revealed that the Schiff base ligand exhibited the poor antimicrobial activity against Escherichia coli and Candida albicans except for Staphylococcus aureus. Generally, Gram-negative bacteria shows rigid outer membrane, well enough to defend against the drug but Schiff base (citral with valine derived) impregnated cobalt(II) complex seem to be more active against Escherichia coli organisms in comparison to copper(II) complex, which exhibits higher activity than uncomplexed ligand. The antimicrobial results revealed that cobalt(II) and copper(II) complexes have a considerable antibacterial activity than antifungal activity and suggest their potential application as antibacterial agents.

Corrosion of Copper-bearing High Strength Mooring Chain Steel Affected by Microbes in Seawater

Corrosion behavior of copper-free (BR5) and copper-bearing (BR5Cu, 0.8% Cu) bainite type grade R5 mooring chain steels is investigated in sterile and bacteria-containing seawater. Electrochemical impedance spectroscopy and weight loss results demonstrate that both steels corrode steadily with similar rates in sterile seawater, which is closely related to stable dissolved oxygen (DO) concentration and loose corrosion product layers. While in bacteria-containing seawater, corrosion is inhibited at the initial stage due to DO consumption and biofilm formation, and the inhibition efficiency declines with time because of bacteria decay, leading to a slightly smaller total weight loss than that in sterile media. Although less adhesive bacteria are observed on BR5Cu steel owing to the antimicrobial activity of copper, it does not bring a visible difference in corrosion rate. The validity of copper introduction in mooring chain steel towards seawater corrosion and MIC inhibition is expected to be checked further in different systems.

Synthesis, structural characterization, thermal behaviour and antimicrobial activity of copper, cadmium and zinc chelates of traizole-thiole ligand in comparison with theoretical molecular orbital calculations

This research involved structural and molecular behaviour of the ligand HL, 4-amino-5-(2,2-dichloro-1-methylcyclopropyl)-4H-1,2,4-triazole-3-thiol toward the transition metal ions namely Cu (II), Cd(II) and Zn (II) had been studied using elemental analyses, magnetic, electronic, FT- IR, 1H-NMR, XRD and Thermal analyses (TGA and DTA). The interpretation of practical data obtained had been evaluated and confirmed by theoretical molecular modelling. The computations had been done by software of Gaussian 09W package. The geometries of traizole-thiole ligand and its metal chelates were fully optimized using density functional theory B3LYP method. There are no symmetry constrains had been applied during geometry optimization. (DFT)/GENECP level by implementing Def2TZVP basis set was used for Cu, Cd and Zn-atoms; and basis set 6-311++G (d, p) was used for other atoms. The mixed basis set had been selected due to its flexibility. HOMO and LUMO energy values for chelates, chemical hardness and electronegativity had been calculated. NBO calculations had been done at the same level using (NBO 3.1) program involved in the software of Gaussian 09W for measuring the intra-molecular delocalization in systems under investigation qualitatively. TD-DFT approximation at the same level of theory was used to calculate the electronic absorption spectra of the studied chelates. Their structures were confirmed via correlation between experimental and theoretical calculations. The ligand and its metal chelates biological activities had been tested against Gram-positive (Staphylococcus aureus ATTC 12600), Gram-negative (Escherichia coli ATTC 11775 and) bacteria, two fungus (Aspergillus flavus and Candida albicans).. These biological activities are tested and give the order Zn-HL˃ Cd-HL˃ Cu-HL ˃˃ HL as a general trend in relation to transition metal cation present in chelate entity. This trend is also correlated to theoretical calculations of chelates electronegativity (X), polarizability and HOMO and LUMO values. Also this trend is correlated to theoretical calculations of energy gap values eV (Zn- HL = 5.19, Cd-HL = 4.32 and Cu-HL = 2.08) and in reverse order to electronegativity (X) values. The variation of electronegativity (X) values is supported by electrostatic potential, for any two molecules, where electron will be partially transferred from one of low X to that of high X. The results show that the order of decreasing X (increasing CT within the molecules) is: Cu-HL > Cd-HL > Zn-HL >> HL. Some of them have the order of magnitude effect like standard Amoxicillin.

Synthesis, spectroscopic characterization, x‐ray crystal structures, thermal behavior and antimicrobial activity of copper(II) complexes with the novel (3,5‐dimethyl‐1H‐pyrazol‐1‐yl)(morpholin‐4‐yl)methanethione

The new (3,5‐dimethyl‐1H‐pyrazol‐1‐yl)(morpholin‐4‐yl) methanethione ligand (L) and its copper(II) chelates Cu(L)Br2 (1), Cu(L)Cl2 (2) and [Cu(L)2OH(H2O)]ClO4·1.5H2O (3) have been prepared. The coordination behavior of the ligand and the properties of the chelate compounds have been investigated by several physico‐chemical techniques. The structures of (L), (1), and (2) have been characterized by x‐ray single crystal diffraction. The ligand (L) crystalizes in the monoclinic P21/n space group, a = 11.2632(4), b = 7.9959(2), c = 13.4337(5) Å, α = 90, β = 106.3080(14), γ = 90°. The copper(II) complexes (1) and (2) show a distorted square‐planar geometries, with the ligand behaves as a bidentates NS chelating agent, coordinating to the copper(II) ions through the N atom of the pyrazolyl ring and the thione S atom, the third and fourth coordination sites are occupied by two halogen (Br− or Cl−) ions. The ESR spectra of the prepared complexes are consistent with d(x2‐y2)1 ground state with axial symmetry. The thermal analysis data of the Cu(II) complexes (1 and 2) indicated that they have similar thermal degradation pathways. The complexes displayed antimicrobial activity against various pathogenic bacteria and fungi higher than that of the free organic ligand. The reaction of Cu(L)Cl2 (2) with pyridine (py) in ethanol at room temperature does not form mixed‐ligand complex, but leads to complete substitution of the ligand (L). The product of the substitution reaction was characterized based on elemental analyses and FT‐IR measurements.

Synthesis, structures and antimicrobial activity of copper derivatives ofN-substituted imidazolidine-2-thiones: unusual bio-activity againstStaphylococcus epidermidisandEnterococcus faecalis

Synthesis and antimicrobial activity of copper(i) complexes withN-substituted imidazolidine-2-thiones is investigated.

Antibiotic resistance, ability to form biofilm and susceptibility to copper alloys of selected staphylococcal strains isolated from touch surfaces in Polish hospital wards

BackgroundDespite the employment of sanitary regimes, contact transmission of the aetiological agents of hospital infections is still exceedingly common. The issue of microbe transmission becomes particularly important when facing multidrug-resistant microorganisms such as methicillin-resistant staphylococci. In the case of deficiencies in cleaning and disinfection procedures, hospital equipment made of copper alloys can play an important role, complementing traditional hospital hygiene procedures.The objective of this study was to characterize staphylococcal strains isolated from touch surfaces in Polish hospital wards in terms of their drug resistance, ability to form biofilm and susceptibility to antimicrobial activity of copper alloys.MethodsThe materials for the study were 95 staphylococcal strains isolated from touch surfaces in 13 different hospital wards from Małopolska province (the south of Poland). Phenotypic and genotypic antibiotic resistance were checked for erythromycin, clindamycin, gentamycin, ciprofloxacin, trimethoprim/sulfamethoxazole and mupirocin. Biofilm formation ability for the tested strains was checked with the use of culture on Congo red agar. Susceptibility to copper, tin bronze, brass and new silver was tested using a modification of the Japanese standard.ResultsOver 67% of the analysed staphylococcal strains were methicillin-resistant (MR). Four strains were resistant to all of the tested antibiotics, and 14 were resistant to all except mupirocin. Strains classified as MR had significantly increased resistance to the remaining antibiotic groups. About one-third of the analysed strains revealed biofilm-forming ability. Among the majority of species, biofilm-forming and non-biofilm-forming strains were distributed evenly; in the case of S. haemolyticus only, negative strains accounted for 92.8%. Susceptibility to copper alloys was different between strains and rather lower than in the case of the SA strain selected for comparison.ConclusionsCoagulase-negative staphylococci, the most commonly isolated in Polish hospital wards, should not be neglected as an infection risk factor due their high antibiotic resistance. Our experiments confirmed that touch surfaces made of copper alloys may play an important role in eliminating bacteria from the hospital environment.

Synthesis, crystal structures, and antimicrobial activity of copper(II) and zinc(II) complexes derived from 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol

An end-to-end azido-bridged dinuclear copper(II) complex [Cu2L2(μ1,3-N3)](NO3) (I) and a mononuclear zinc(II) complex [ZnCl2(HL)] • CH3OH (II), where L is 2-brom-4-chloro-6-[(2-morpholin- 4-ylethylimino)methyl]phenolate, have been prepared and characterized by elemental analyses, IR, and single crystal X-ray crystallographic determination (CIF files CCDC nos. 1415217 (I), 1415218 for (II)). The crystal of I is monoclinic: space group C2/c, a = 28.684(2), b = 7.1787(5), c = 18.292(1) A, β = 117.887(3)°, V = 3329.1(4) A3, Z = 4. The crystal of II is monoclinic: space group P21/c, a = 10.8207(9), b = 12.3398(7), c = 14.9477(7) A, β = 93.473(3)°, V = 1992.2(2) A3, Z = 4. The Schiff base ligand in I coordinates to the Cu atom through the phenolate O, imine N, and morpholine N atoms, while the Schiff base ligand in II coordinates to the Zn atom through the phenolate O and imine N atoms, with the morpholine N atom protonated. The effect of these complexes on the antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans was studied.

Synthesis, crystal structures, and antimicrobial activity of copper(II) and zinc(II) complexes derived from 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol

Synthesis, crystal structures, and antimicrobial activity of copper(II) and zinc(II) complexes derived from 2-bromo-4-chloro-6-[(2-morpholin-4-ylethylimino)methyl]phenol