Metal complexes of omeprazole. Preparation, spectroscopic and thermal characterization and biological activity

EDTA enables to alleviate impacts of metal ions on conjugative transfer of antibiotic resistance genes

Various heavy metals are reported to be able to accelerate horizontal transfer of antibiotic resistance genes (ARGs). In real water environmental settings, ubiquitous complexing agents would affect the environmental behaviors of heavy metal ions due to the formation of metal-organic complexes. However, little is known whether the presence of complexing agents would change horizontal gene transfer due to heavy metal exposure. This study aimed to fill this gap by investigating the impacts of a typical complexing agent ethylenediaminetetraacetic acid (EDTA) on the conjugative transfer of plasmid-mediated ARGs induced by a range of heavy metal ions. At the environmentally relevant concentration (0.64 mg L-1) of metal ions, all the tested metal ions (Mg2+, Ca2+, Co2+, Pb2+, Ni2+, Cu2+, and Fe3+) promoted conjugative transfer of ARGs, while an inhibitory effect was observed at a relatively higher concentration (3.20 mg L-1). In contrast, EDTA (0.64 mg L-1) alleviated the effects of metal ions on ARGs conjugation transfer, evidenced by 11 %-66 % reduction in the conjugate transfer frequency. Molecular docking and dynamics simulations disclosed that this is attributed to the stronger binding of metal ions with the lipids in cell membranes. Under metal-EDTA exposure, gene expressions related to oxidative stress response, cell membrane permeability, intercellular contact, energy driving force, mobilization, and channels of plasmid transfer were suppressed compared with the metal ions exposure. This study offers insights into the alleviation mechanisms of complexing agents on ARGs transfer induced by free metal ions.

An amplified electrochemical sensor employing one-step synthesized nickel-copper-zinc ferrite/carboxymethyl cellulose/graphene oxide nanosheets composite for sensitive analysis of omeprazole

In this work, a signal amplification strategy was designed by the fabrication of a highly sensitive and selective electrochemical sensor based on nickel-copper-zinc ferrite (Ni0.4Cu0.2Zn0.4Fe2O4)/carboxymethyl cellulose (CMC)/graphene oxide nanosheets (GONs) composite modified glassy carbon electrode (GCE) for determination of omeprazole (OMP). The one-step synthesized Ni0.4Cu0.2Zn0.4Fe2O4/CMC/GONs nanocomposite was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy and X-ray diffraction techniques. Then, the Ni0.4Cu0.2Zn0.4Fe2O4/CMC/GONs/GCE was applied to study the electrochemical behavior of the OMP. Electrochemical data show that the Ni0.4Cu0.2Zn0.4Fe2O4/CMC/GONs/GCE exhibits superior electrocatalytic performance on the oxidation of OMP compared with bare GCE, GONs/GCE, CMC/GONs/GCE and MFe2O4/GCE (M = Cu, Ni and Zn including single, double and triple of metals) which can be attributed to the synergistic effects of the nanocomposite components, outstanding electrical properties of Ni0.4Cu0.2Zn0.4Fe2O4 and high conductivity of CMC/GONs as well as the further electron transport action of the nanocomposite. Under optimal conditions, the Ni0.4Cu0.2Zn0.4Fe2O4/CMC/GONs/GCE offers a high performance toward the electrodetermination of OMP with the wide linear-range responses (0.24-5 and 5-75 μM), lower detection limit (0.22 ± 0.05 μM), high sensitivity (1.1543 μA μM-1 cm-2), long-term signal stability and reproducibility (RSD = 2.54%). It should be noted that the Ni0.4Cu0.2Zn0.4Fe2O4/CMC/GONs/GCE sensor could also be used for determination of OMP in drug and biological samples, indicating its feasibility for real analysis.

Spectroscopic study of in situ-formed metallocomplexes of proton pump inhibitors in water

Proton pump inhibitors, such as omeprazole, pantoprazole and lansoprazole, are an important group of clinically used drugs. Generally, they are considered safe without direct toxicity. Nevertheless, their long-term use can be associated with a higher risk of some serious pathological states (e.g. amnesia and oncological and neurodegenerative states). It is well known that dysregulation of the metabolism of transition metals (especially iron ions) plays a significant role in these pathological states and that the above drugs can form complexes with metal ions. However, to the best of our knowledge, this phenomenon has not yet been described in water systems. Therefore, we studied the interaction between these drugs and transition metal ions in the surrounding water environment (water/DMSO, 99:1, v/v) by absorption spectroscopy. In the presence of Fe(III), a strong redshift was observed, and more importantly, the affinities of the drugs (represented as binding constants) were strong enough, especially in the case of omeprazole, so that the formation of a metallocomplex cannot be excluded during the explanation of their side effects.

Synthesis, Spectroscopic Characterization, and Biological Activities of Metal Complexes of 4-((4-Chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol

Azo Schiff base complexes of VO(II), Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from 4-((4-chlorophenyl)diazenyl)-2-((p-tolylimino)methyl)phenol (CDTMP). The nature of bonding and the structural features of the complexes have been deduced from elemental analysis, molar conductance, magnetic susceptibility measurements, IR, UV-Vis,1H-NMR, EPR, mass, SEM, and fluorescence spectral studies. Spectroscopic and other analytical studies reveal square-planar geometry for copper, square-pyramidal geometry for oxovanadium, and octahedral geometry for other complexes. The EPR spectra of copper(II) complex in DMSO at 300 K and 77 K were recorded, and its salient features are reported. Antimicrobial studies against several microorganisms indicate that the complexes are more potent bactericides and fungicides than the ligand. The electrochemical behavior of the copper(II) complex was studied by cyclic voltammetry. All the synthesized compounds can serve as potential photoactive materials as indicated from their characteristic fluorescence properties. The second harmonic conversion efficiency of the synthesized azo Schiff base was found to be higher than that of urea and KDP (potassium dihydrogen phosphate). SEM image of copper(II) complex implies the crystalline state and surface morphology of the complex.

Synthesis, Characterization, and Physicochemical Studies of Mixed Ligand Complexes of Inner Transition Metals with Lansoprazole and Cytosine

Few complexes of inner transition metals [Th(IV), Ce(IV), Nd(III), Gd(III)] have been synthesized by reacting their metal salts with lansoprazole, 2-([3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl]methylsulfinyl)-1H-benzoimidazole and cytosine. All the complexes were synthesized in ethanolic medium. The yield percentage rangs from 80 to 90%. The complexes are coloured solids. The complexes were characterized through elemental analyses, conductance measurements, and spectroscopic methods (FT IR, FAB Mass,1H NMR and UV). An IR spectrum indicates that the ligand behaves as bidentate ligands. The metal complexes have been screened for their antifungal activity towardsAspergillus nigerfungi. The interaction of inner transition metals with lansoprazole, in presence of cytosine, has also been investigated potentiometrically at two different temperatures26±1°C and36±1°C and at 0.1 M (KNO3) ionic strength. The stability constants of ternary complexes indicate the stability order as Th(IV) < Ce(IV) < Gd(III) < Nd(III).logKvalues obtained are positive and suggest greater stabilization of ternary complexes. The values of thermodynamic parameters (free energy (ΔG), enthalpy (ΔH), and entropy (ΔS) are also calculated.

Synthesis, spectroscopic characterization and biological activities of N₄O₂ Schiff base ligand and its metal complexes of Co(II), Ni(II), Cu(II) and Zn(II)

The Schiff base ligand, bis(indoline-2-one)triethylenetetramine (L) obtained from condensation of triethylenetetramine and isatin was used to synthesize the complexes of type, [ML]Cl(2) [M=Co(II), Ni(II), Cu(II) and Zn(II)]. L was characterized on the basis of the results of elemental analysis, FT-IR, (1)H and (13)C NMR, mass spectroscopic studies. The stoichiometry, bonding and stereochemistries of complexes were ascertained on the basis of results of elemental analysis, magnetic susceptibility values, molar conductance and various spectroscopic studies. EPR, UV-vis and magnetic moments revealed an octahedral geometry for complexes. L and its Cu(II) and Zn(II) complexes were screened for their antibacterial activity. Analgesic activity of Cu(II) and Zn(II) complexes was also tested in rats by tail flick method. Both complexes were found to possess good antibacterial and moderate analgesic activity.

Preparation, spectroscopic and thermal characterization of new metal complexes of verlipride drug. In vitro biological activity studies

Metal complexes of the general formula [M(VER)(2)Cl(2)(H(2)O)(2)]·yH(2)O and [Cr(VER)(2)Cl(2)(H(2)O)(2)]Cl·H(2)O (where VER=verlipride, M=Mn(II) (y=2), Co(II) (y=2), Ni(II) (y=2), Cu(II) (y=1) and Zn(II) (y=0)) are prepared and characterized based on elemental analyses, IR, (1)H NMR, magnetic moment, molar conductance, and thermal analyses (TG and DTA) techniques. From the elemental analyses data, the complexes are formed in 1:2 [Metal]:[VER] ratio. The molar conductance data reveal that all the metal chelates are non-electrolytes except Cr(III) complex, it is 1:1 electrolyte. IR spectra show that VER is coordinated to the metal ions in a neutral monodentate manner with O donor site of the carbonyl O atom. On the basis of spectral studies and magnetic moment measurements an octahedral geometry has been assigned for the complexes. The thermal behavior of these chelates is studied using thermogravimetric analysis technique. The results obtained show that the complexes lose hydrated water, HCl and coordinated water molecules followed immediately by decomposition of the ligand molecules in the successive unseparate steps. The VER drug, in comparison to its metal complexes is also screened for its biological activity against Gram positive bacterial (Staphylococcus aureus) and Gram negative bacteria (Escherichia coli) and fungi (Candida albicans and Aspergillus flavus) in vitro. The activity data show that most of the metal complexes have antibacterial activity like or higher than that of the parent VER drug against one or more species.

Synthesis, characterization and biological activity of some new VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) complexes of chromone based NNO Schiff base derived from 2-aminothiazole

Coordination compounds of VO(IV), Co(II), Ni(II), Cu(II) and Zn(II) with the Schiff base obtained through the condensation of 2-aminothiazole with 3-formyl chromone were synthesized. The compounds were characterized by (1)H, (13)C NMR, UV-Vis, IR, Mass, EPR, molar conductance and magnetic susceptibility measurements. The Cu(II) complex possesses tetrahedrally distorted square planar geometry whereas Co(II), Ni(II), and Zn(II) show distorted tetrahedral geometry. The VO(IV) complex shows square pyramidal geometry. The cyclic voltammogram of Cu (II) complex showed a well defined redox couple Cu(II)/Cu(I) with quasireversible nature. The antimicrobial activity against the species Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albigans and Aspergillus niger was screened and compared to the activity of the ligand. Emission spectrum was recorded for the ligand and the metal(II) complexes. The second harmonic generation (SHG) efficiency was measured and found to have one fourth of the activity of urea. The SEM image of the copper(II) complex implies that the size of the particles is 2 μm.

Synthesis, spectroscopic and thermal characterization of sulpiride complexes of iron, manganese, copper, cobalt, nickel, and zinc salts. Antibacterial and antifungal activity

Sulpiride (SPR; L) is a substituted benzamide antipsychotic which is reported to be a selective antagonist of central dopamine receptors and claimed to have mood-elevating properties. The ligation behaviour of SPR drug is studied in order to give an idea about its potentiality towards some transition metals in vitro systems. Metal complexes of SPR have been synthesized by reaction with different metal chlorides. The metal complexes of SPR with the formula [MCl(2)(L)(2)(H(2)O)(2)].nH(2)O [M=Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); n=0-2] and [FeCl(2)(HL)(H(2)O)(3)]Cl.H(2)O have been synthesized and characterized using elemental analysis (CHN), electronic (infrared, solid reflectance and (1)H NMR spectra) and thermal analyses (TG and DTA). The molar conductance data reveal that the bivalent metal chelates are non-electrolytes while Fe(III) complex is 1:1 electrolyte. IR spectra show that SPR is coordinated to the metal ions in a neutral monodentate manner with the amide O. From the magnetic and solid reflectance spectra, octahedral geometry is suggested. The thermal decomposition processes of these complexes were discussed. The correlation coefficient, the activation energies, E*, the pre-exponential factor, A, and the entropies, DeltaS*, enthalpies, DeltaH*, Gibbs free energies, DeltaG*, of the thermal decomposition reactions have been derived from thermogravimetric (TG) and differential thermogravimetric (DTG) curves. The synthesized ligand and its metal complexes were also screened for their antibacterial and antifungal activity against bacterial species (Escherichia coli and Staphylococcus aureus) and fungi (Aspergillus flavus and Candida albicans). The activity data show that the metal complexes are found to have antibacterial and antifungal activity than the parent drug and less than the standard.

Preparation, characterization and biological activity of novel metal-NNNN donor Schiff base complexes

Novel Schiff base (H(2)L) ligand is prepared via condensation of benzil and triethylenetetraamine. The ligand is characterized based on elemental analysis, mass, IR and (1)H NMR spectra. Metal complexes are reported and characterized based on elemental analyses, IR, (1)H NMR, solid reflectance, magnetic moment, molar conductance, and thermal analyses (TG, DTG and DTA). 1:1 [M]:[H(2)L] complexes are found from the elemental analyses data having the formulae [M(H(2)L)Cl(2)]xyH(2)O (M=Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II)), [Fe(H(2)L)Cl(2)]ClxH(2)O, [Th(H(2)L)Cl(2)]Cl(2)x3H(2)O and [UO(2)(H(2)L)](CH(3)COO)(2)x2H(2)O. The metal chelates are found to be non-electrolytes except Fe(III), Th(IV) and UO(2)(II) complexes are electrolytes. IR spectra show that H(2)L is coordinated to the metal ions in a neutral tetradentate manner with 4Ns donor sites of the two azomethine N and two NH groups. The geometrical structures of these complexes are found to be octahedral. The thermal behaviour of these chelates is studied where the hydrated complexes lose water molecules of hydration in the first step followed immediately by decomposition of the anions and ligand molecules in the subsequent steps. The activation thermodynamic parameters are calculated using Coats-Redfern method. The ligand (H(2)L), in comparison to its metal complexes, is screened for its antibacterial activity. The activity data show that the metal complexes have antibacterial activity more than the parent Schiff base ligand and cefepime standard against one or more bacterial species.