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Several novel copper (II) complexes of reduced Schiff bases containing fluoride substituents were prepared and structurally characterized by single-crystal X-ray diffraction. The complexes exhibited diverse structures, with the central atom in distorted tetrahedral geometry. The biological effects of the products were evaluated, specifically their cytotoxicity, antimicrobial, and antiurease activities, as well as affinity for albumin (BSA) and DNA (ct-DNA). The complexes showed marked cytotoxic activities in the HepG2 hepatocellular carcinoma cell line, considerably higher than the standard cisplatin. The cytotoxicity depended significantly on the substitution pattern. The best activity was observed in the complex with a trifluoromethyl group in position 4 of the benzene ring—the dichloro[(±)-trans-N,N′-bis-(4-trifluoromethylbenzyl)-cyclohexane-1,2-diamine]copper (II) complex, whose activity (IC50 28.7 μM) was higher than that of the free ligand and markedly better than the activity of the standard cisplatin (IC50 336.8 μM). The same complex also showed the highest antimicrobial effect in vitro. The affinity of the complexes towards bovine serum albumin (BSA) and calf thymus DNA (ct-DNA) was established as well, indicating only marginal differences between the complexes. In addition, all complexes were shown to be excellent inhibitors of the enzyme urease, with the IC50 values in the lower micromolar region. [ABSTRACT FROM AUTHOR]

Background: The ineffectiveness of treatments for infections caused by biofilm-producing pathogens and human carcinoma presents considerable challenges for global public health organizations. To tackle this issue, our study focused on exploring the potential of synthesizing new complexes of Co(II), Cu(II), Ni(II), and Zn(II) with sorbic acid to enhance its antibacterial, antibiofilm, and anticancer properties. Methods: Four novel complexes were synthesized as solid phases by reacting sorbic acid with Co(II), Cu(II), Ni(II), and Zn(II). These complexes were characterized by various technique, including infrared spectra, UV–Visible spectroscopy, proton nuclear magnetic resonance (1H NMR), and thermal analysis techniques, including thermogravimetry (TG). Results: The data acquired from all investigated chemical characterization methods confirmed the chemical structure of the sorbate metal complexes. These complexes exhibited antibacterial and antibiofilm properties against both Gram-positive and Gram-negative bacteria. Furthermore, these complexes enhanced the antibacterial effects of commonly used antibiotics, such as gentamicin and imipenem, with fractional inhibitory concentration (FIC) indices ≤ 0.5. Notably, the Cu(II) complex displayed the most potent antibacterial and antibiofilm activities, with minimum inhibitory concentration (MIC) values of 312.5 µg/mL and 625.0 µg/mL for Bacillus cereus and Escherichia coli, respectively. Additionally, in vitro assays using the methyl thiazolyl tetrazolium (MTT) method showed inhibitory effects on the growth of the human colon carcinoma cell line (HCT-116 cells) following treatment with the investigated metal complexes. The IC50 values for Co(II), Cu(II), Zn(II), and Ni(II) were 3230 µg/mL, 2110 µg/mL, 3730 µg/mL, and 2240 µg/mL, respectively. Conclusion: Our findings offer potential for pharmaceutical companies to explore the development of novel combinations involving traditional antibiotics or anticancer drugs with sorbate copper complex. [ABSTRACT FROM AUTHOR]

New 2-[(4-[(4-methylphenyl)sulfonothioyl)methylene]aminobenzoic acid ligand-Co(II), Ni(II), and Cu(II) complexes are synthesized and characterized in this article. Elemental analysis, mass spectroscopy, conductivity tests, magnetic susceptibility, Fourier transform infrared spectroscopy, thermogravimetric analysis, electronic absorption spectroscopy, and density functional theory calculations were used to determine the coordination mode, and geometry of the synthesized compounds. The Schiff-base ligand was shown to be mononegatively charged and coordinate to metal ions in a bi-dentate mode through azomethine nitrogen (-CH=N-) and carboxylic Oxygen (-COOH). Density functional theory (DFT) calculations were performed in addition to the experimental data to assess the most probable structures of the complexes. In addition, the biological activities of these compounds were evaluated by in vitro antibacterial and antifungal assays. These novel Co(II), Ni(II), and Cu(II) compounds were shown to be active against a wide variety of microorganisms, including Gram-positive and Gram-negative bacteria, as well as fungi. Following that, molecular docking was used to analyze the complexes' interactions with bacterial proteins, validating the therapeutic potential of the metal-containing compounds. [ABSTRACT FROM AUTHOR]

A series of transition metal complexes of Mn(II),Co(II), Ni(II), Cu(II), Zn(II) and VO(II) have been prepared by using the Schiff base ligand (L) derived from 4-aminoantipyrine and 5-chlorosalicylaldehyde. The structural properties of Schiff base ligand were characterized by mass, FT-IR, UV--Vis, ¹H-NMR spectroscopy, etc. Also, metal complexes were studied by P- -XRD, elemental analysis, thermogravimetric studies along with various biological activities. The micro analytical data revealed that, the metal complexes have 1:1 stoichiometry composition of M:L. Generally, it is observed that prepared metal complexes show better antifungal, antibacterial and anticancer activities than its Schiff base ligand. [ABSTRACT FROM AUTHOR]

The ligand, N′-(furan-2-ylmethylene)-2-hydroxybenzohydrazide (H2L), was synthesized characterized through various spectral studies which cleared out that the free ligand existed in keto form. The ligand upon reaction with Cu(II), Co(II), Ni(II) and Zn(II) acetates yielded complexes with stoichiometric ratio 1:2 (M:L) which has been validated through the elemental and mass spectral measurements. The IR and NMR spectral studies of the isolated complexes disclosed that the ligand chelated to metal ion in mononegative bidentate fashion via the azomethine nitrogen and deprotonated enolized carbonyl oxygen. Moreover, the DFT quantum chemical calculations designated that the ligand and Ni(II) complex exhibited the highest and lowest values of HOMO, LUMO energies and HOMO-LUMO energy gap, respectively. Furthermore, the in vitro cytotoxic activity towards HePG-2 and HCT-116 cell lines of the isolated compounds was investigated and the data cleared out that the ligand was more potent than the metal complexes. [ABSTRACT FROM AUTHOR]

An ionic liquid tagged schiff base, [1-{2-(2-hydroxybenzylideneamino)ethyl}-3-methylimidazolium]PF6 was synthesized from a functionalized ionic liquid (FIL) 2-aminoethyl-3-methylimidazolium hexafluorophosphate, [2-aemim]PF6 and salicylaldehyde without using any organic solvent. The Schiff base was used as a ligand to trap Mn(II), Co(II), Cu(II) ions from its corresponding metal acetates and to form the new transition metal complexes. The synthesized Mn(II), Co(II), Cu(II) complexes along with the Schiff base were characterized by ESI-MS, PXRD, UV-Visible, FT-IR, 1H NMR spectroscopic and analytical (elemental analysis and magnetic susceptibility measurements) methods. Based on these spectral analysis data tetra coordinated geometries were assigned for the newly synthesized metal(II) complexes. Antibacterial sensitivity of the Schiff base and the Mn(II), Co(II), Cu(II) complexes were evaluated against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria to assess their minimum zone of inhibition. [ABSTRACT FROM AUTHOR]

The aim of the present study is to synthesize new metal complexes of 6-methyl-2-thiouracil and 6-propyl-2-thiouracil, elucidate their structures, and investigate their biological properties. All metal complexes were obtained after mixing water solutions of the corresponding metal salts and the ligand dissolved in DMSO and water solutions of NaOH in a metal-to-ligand ratio of 1:4:2. The structures of the new compounds are discussed based on melting point analysis (MP-AES) for Cu and Pd, UV-Vis, IR, ATR, 1H NMR, 13C NMR, and Raman spectroscopy. The interpretation of complex spectra is assisted by the data for 6-methyl-2-thiouracil and 6-propyl-2-thiouracil obtained from 1H-1H COSY, DEPT-135, HMBC and HMQC spectra. In addition, the antimicrobial activity of these complexes and the free ligands are assessed against both Gram-positive and Gram-negative bacteria, as well as yeasts. In general, the addition of metal ions improved the antimicrobial activity of both 6-methyl-2-thiouracil and 6-propyl-2-thiouracil. The Cu(II) complex with 6-methyl-2-thiouracil and the Pd(II) complex with 6-propyl-2-thiouracil exhibited the highest activity against the test microorganisms. [ABSTRACT FROM AUTHOR]

The ligand N-{[(phenyl amino) thioxomethyl] hydrazino carbonyl methyl} trimethyl ammonium chloride (PTHAC) was prepared by the refluxing phenyl isothiocyanate and Girard-T (trimethyl ammonium-acethydrazide) in a molar ratio (1:1). The metal complexes derived from NiCl2.6H2O, CuCl2.2H2O and Co(CH3COO)2.6H2O were synthesized and purified. The PTHAC and its Cu(II), Co(II), and Ni(II) metal complexes(1–3) were characterized using a variety of various instrumental performances such as elemental analysis, magnetic moment, spectra (IR, UV–Vis, 1H NMR, mass) and thermal analysis (TGA and DTG).The results of element analysis, magnetic moment, spectra (IR, UV–Vis, 1H NMR, mass), and thermal (TGA and DTA) analyses provide the structures of the produced ligand and its (1–3) complexes. According to the spectroscopic results, PTHAC acts as an O, N and S tridentate donor, creating a mononuclear complex with copper(II), cobalt(II), and nickel(II) ions with an octahedral geometry. All of the atomic properties, including bond lengths, bond angles, HOMO, LUMO, dipole moments, and charges, have been determined. The cytotoxic activities of the PTHAC and the produced (1–3) complexes against breast carcinoma cells have been studied and correlated to the molecular modeling. When compared to the free ligand, CoII-L, and NiII-L, the CuII-L complex inhibits breast cancer cell growth more effectively. Furthermore, the PTHAC ligand was successfully applied for separation via flotation and spectrophotometric determination of Co(II) in several natural water, certified ore and pharmaceutical samples using oleic acid surfactant (HOL). At pH 6.5, PTHAC reacted with Co(II) to create a dark green (1:1) Co(II):PTHAC complex that was floated significantly using oleic acid (HOL) surfactant. The different experimental variable affecting the separation procedure e.g. pH, concentration of Co(II), HOL, PTHAC, temperature etc...., were investigated. Co(II) had a linear range of (0.1–7.0) mgL−1. In the aqueous and scum layers, the molar absorptivities for the coloured complex are 0.14 × 104 and 0.16 × 105Lmol−1 cm−1, respectively. The LOD was 0.04 mgL−1, which is related to Sandell sensitivity of 3.7 × 10−3 µg cm−2 with a preconcentration factor of 200 and a RSD, % (n = 5) less than 4.2%. In addition, the mechanisms involved in the process of coordination of PTHAC with Cu(II), Co(II) and Ni(II) and the mechanism involved in the process of flotation of the PTHAC-Co(II) complex using HOL surfactant were elucidated. [ABSTRACT FROM AUTHOR]

In this study, we report the cytotoxicity of a newly synthesized Schiff base HL ((E)-2-ethoxy-6((pyren-1-ylimino)methyl)phenol) and its derived metal complexes (Zn(II), Cu(II), Co(II), Cr(III), and Fe(III)) along with their structural characterizations by means of elemental analysis, magnetic moment, molar conductance, IR, UV-Vis, ESR, and mass spectrometry. The single X-ray diffraction of the HL shows that it exists in the phenol-imine form in its solid state. The NMR and IR data indicate that the bidentate binding of the Schiff base ligand with the metal center occurs during complexation through the azomethine nitrogen atom and the hydroxyl group oxygen atom of the 3-ethoxy salicylaldehyde. The electronic spectra and magnetic measurements indicate that the Co(II) complex has a tetrahedral geometry and that the Cr(III) and Fe(III) complexes have a distorted octahedral geometry. The ESR and electronic spectra suggest that the Cu(II) complex has a distorted tetrahedral geometry. The cytotoxic effects of the HL and all of the metal complexes were studied using human breast cancer (MCF-7) cells. The Cu(II) and Zn(II) complexes exhibited the highest activity against the tested cell line, with IC50 values of 5.66 and 12.74 μg/mL, respectively, and their activity was higher than that of the fluorouracil cancer drug against the MCF-7 cells (18.05 μg/mL). [ABSTRACT FROM AUTHOR]

New benzohydrazone compound, 4-amino-N'-[(1E)-1-(2-hydroxy-6-methyl-4-oxo-4H-pyran-3-yl)ethylidene] benzohydrazide (HL1) and its Cu(II), Ni(II), Zn(II) and Mn(II) complexes were synthesized. The structures of HL1 and its complexes were elucidated by elemental analysis and IR, UV-Vis, 1H and 13C NMR spectroscopy and mass spectrometry. The infrared spectral data of the complexes revealed that HL1 coordinated with the metal ions through azomethine nitrogen, enolic oxygen and amide carbonyl oxygen atoms, hence, HL1 behaves as a monobasic tridentate ligand. UV-Vis data revealed that Zn(II) and Mn(II) complexes adopted octahedral geometry, while Cu(II) and Ni(II) complexes had five-coordinate and square-planar geometries respectively. The mass spectra data and elemental analysis values are in accordance with the calculated values for the suggested molecular formula of the complexes, a confirmation of the 1:1 ligand to metal stoichiometry in case of Cu(II) complex and 2:1 ligands to metal stoichiometry in case of the other complexes. [ABSTRACT FROM AUTHOR]

Developing a new generation of anticancer metal-based drugs that can both kill tumor cells and inhibit cell migration is a promising strategy. Herein, we synthesized three Cu(II), Zn(II), and Mn(II) complexes derived from 5-chloro-2-N-(2-quinolylmethylene)aminophenol (C1–C3). Among these complexes, the Cu(II) complex (C1) showed significantly greater cytotoxicity toward lung cancer cell lines than cisplatin. C1 inhibited A549 cell metastasis and suppressed the growth of the A549 tumor in vivo. In addition, we confirmed the anticancer mechanism of C1 by triggering multiple mechanisms, including inducing mitochondrial apoptosis, acting on DNA, blocking cell cycle arrest, inducing cell senescence, and inducing DNA damage. [ABSTRACT FROM AUTHOR]

New series of Cu(II) and Mn(II) complexes with Schiff base ligands derived from 2-furylmethylketone (Met), 2-furaldehyde (Fur), and 2-hydroxyacetopheneone (Hyd) have been synthesized in situ on SBA-15-NH2, MCM-48-NH2, and MCM-41-NH2 functionalized supports. The hybrid materials were characterized by X-ray diffraction, nitrogen adsorption–desorption, SEM and TEM microscopy, TG analysis, and AAS, FTIR, EPR, and XPS spectroscopies. Catalytic performances were tested in oxidation with the hydrogen peroxide of cyclohexene and of different aromatic and aliphatic alcohols (benzyl alcohol, 2-methylpropan-1-ol, and 1-buten-3-ol). The catalytic activity was correlated with the type of mesoporous silica support, ligand, and metal–ligand interactions. The best catalytic activity of all tested hybrid materials was obtained in the oxidation of cyclohexene on SBA-15-NH2-MetMn as a heterogeneous catalyst. No leaching was evidenced for Cu and Mn complexes, and the Cu catalysts were more stable due to a more covalent interaction of the metallic ions with the immobilized ligands. [ABSTRACT FROM AUTHOR]

Copyright of Farmacia is the property of Societatea de Stiinte Farmaceutice Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the obvious numerous economic and technical consequences of the corrosion process, its inhibition is one of the most critical aspects of current research. A corrosion inhibitor for the bis-thiophene Schiff base copper–metal complex Cu(II)@Thy-2 was investigated here, which was synthesized via a coordination reaction with a bis-thiophene Schiff base (Thy-2) as a ligand and copper chloride (CuCl2-2H2O) as a ligand metal salt. When the corrosion inhibitor concentration was increased to 100 ppm, the self-corrosion current density Icoor reached a minimum of 2.207 × 10−5 A/cm2, the charge transfer resistance reached a maximum of 932.5 Ω·cm2, and the corrosion inhibition efficiency reached a maximum of 95.2%, with the corrosion inhibition efficiency showing a trend of increasing first and then decreasing with concentration increase. After adding Cu(II)@Thy-2 corrosion inhibitor, a uniformly distributed dense corrosion inhibitor adsorption film formed on the surface of the Q235 metal substrate, significantly improving the corrosion profile compared to both before and after the addition of the corrosion inhibitor. Before and after the addition of corrosion inhibitor, the metal surface's contact angle CA increased from 54.54° to 68.37°, showing that the adsorbed corrosion inhibitor film decreased the metal surface's hydrophilicity and increased its hydrophobicity. [ABSTRACT FROM AUTHOR]

Schiff base ligands are chemical compounds having diverse biological activities like industrial, agriculture and pharmaceutical. The current work discusses the evaluation of the biological properties of different synthesized mononuclear Fe(II), Co(II), Ni(II) and Cu(II) complexes. The complexes were synthesized using a condensation reaction which demonstrated the appearance of White, Cream, Black and Green. Biological activities for synthesized metal complexes were assessed against S. aureus, B. cereus, E. coli and P. aeruginosa and by comparing the zones of inhibition it can be depicted that metal complexes are fairly more effective inhibitors of gram-positive bacteria. Furthermore the antioxidant potential of these complexes was also evaluated and it concluded that copper complexes showed promising antioxidant activity which is higher in association with Ni(II), Fe(II), and Co(II). Hence, these metal complexes were biologically active and further studies are required. [ABSTRACT FROM AUTHOR]

Two tridentate-type Schiff-bases’ ligands: 2,6-bis[(salicylidene) hydrazinocarbonyl] pyridine (L) and 2,6-bis[(3-methoxysalicylidene) hydrazinocarbonyl] pyridine (L') are synthesized from the reaction of pyridine2,6-dicarbohydrazide with salicylaldehyde and 3-methoxy salicylaldehyde. The co-ordination behaviour of the (L) and (L') towards Cu(II) and Co(II) ions is investigated. The reaction of the Schiff-base ligands (L) and (L') with cobalt(II) and copper(II) ions in 1:3 molar ratio affords polynuclear metal complexes. The shifts of the some IR-bands’ spectra of synthesized complex in the selected vibrational bands in FT-IR indicate that Schiff bases behave as trilydentate ligands and co-ordinate to metal ions from phenolic oxygen atoms, amide and azomethine nitrogen atoms. The structure of the metal complexes exhibits octahedral arrangements. The antibacterial activity of the ligand (L) and its metal complexes against two bacterial species is studied. The Co(II) complex indicates a good inhibition activity. The structures of the ligands are elucidated by FT-IR, 1H-NMR, and UV–Vis electronic spectra. The characterization and structure elucidation of the complexes are achieved by FT-IR, UV–Vis electronic spectra. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An ultrasound-assisted synthesis has been used for the preparation of novel benzothiazole Schiff bases (1-3) as ligands for Zn(II) and Cu(II) metal complexes. In this class of Schiff base ligands, the isolated complexes 1a and 2a appear to be the only ones that have structures which include both the Schiff base ligand and the hydrolysis product 2-aminobenzothiazole in the same complex molecule. The aldehydes formed by Schiff base hydrolysis formed a rare example of a trans-isomer in pentacoordinated 2,4-disubstituted benzaldehyde complexes. [ABSTRACT FROM AUTHOR]

A pair of structurally similar dicyanamide bridged copper(II) and zinc(II) complexes [CuL(dca)]n (1) and [ZnL(dca)] n (2), were prepared from the fluorine containing Schiff base 5-fluoro-2-(((2-hydroxyethyl)imino)methyl)phenol (HL). The compounds were characterized by physico-chemical methods. Structures of the complexes were confirmed by single crystal X-ray diffraction. The Cu atom in complex 1 is in square pyramidal coordination, whereas the Zn atom in complex 2 is in trigonal bipyramidal coordination. The copper complex has effective Jack bean urease inhibitory activity, with IC50 value of 0.14 ± 0.12 µmol L-1. [ABSTRACT FROM AUTHOR]

This study has been designed to evaluate some expected synthesized metal complexes with some amino acids as antitumor agent. The metal complexes that were synthesized in this study were Fe (II) with Arg, Zn (II) with Arg, Cu (II) with Arg, Cu (II) with Gly, Fe (II) with His and Zn (II) with His. All of these metal complexes were characterized by elemental analysis, IR spectroscopy, X-Ray diffraction pattern, Mass spectra, Atomic absorption and Scanning Electron Microscope (SEM). The cytotoxicity effect was examined by MTT assay against cancer cell line. The result show Zn (II) with Arg has the more potency against tumor cell line then Fe (II) with His and last was Cu (II) with Arg. Overall; these findings have proved that synthesized complexes could be potent anti- cancer cell line in vitro. [ABSTRACT FROM AUTHOR]

Four new Schiff-base hydrazone ligands were synthesized by the condensation of 2- and 4-aminobenzoylhydrazone with 3-(4-acetylphenoxy)-N,N,Ntrimethylpropane- 1-ammonium and 5-(4-acetylphenoxy)-N,N,N-trimethylpentane-1-ammonium salts. The structures of the ligands were confirmed by means of NMR, FTIR, and elemental analysis. The mononuclear and binuclear copper complexes containing these ligands were also obtained. The hydrazine-Schiff base compounds behave either as bidentate (NO sites) monobasic or tridentate (NNO sites) dibasic as ligands depending on the position of the amino group. Elemental analyses, magnetic susceptibility, FTIR and mass spectroscopy were used to confirm the proposed structures of new copper complexes. DNA binding and cleavage activities of all compounds were investigated. UV-vis spectroscopy results suggest that all compounds preferably bind to DNA via intercalation mode. According to the results of electrophoresis studies, the compounds exhibit significant cleavage activity on the plasmid DNA both in the absence and presence of hydrogen peroxide, depending on the concentration of the compounds. [ABSTRACT FROM AUTHOR]

• Two ferrocenyl Schiff bases and their copper and nickel complexes. • All the compounds have been characterized. • Complexes have better biological activities as compared to Schiff bases. • Copper complexes of both Schiff bases have good anti-diabetic and antioxidant activities. • Both copper complexes showed inhibition against α-Amylase, urease and lipase. Two new Schiff base ligands were synthesized by the reaction of ferrocenyl aniline with aromatic aldehydes which were used for the formation of copper, nickel, and cobalt complexes. The synthesized compounds were characterized by elemental analysis, UV–Visible, FTIR, 1H, and 13CNMR Spectroscopy. The synthesized compounds were screened for various biological activities. The compounds showed moderate to significant activities. From the result, it was clear that metal complexes exhibited significantly better activities than their parent ligands. For anti-bacterial activities, the disk diffusion method was used. In all synthesized compounds, Nickel complexes showed higher results against S. setubal. In anti-fungal activities, Sb1Ni(II) and Sb2Cu(II) showed good results against M. species and F. solani respectively. Copper complexes of both Schiff bases showed good anti-diabetic and antioxidant activities. Copper Complex (Sb1, Sb2) exhibited considerable inhibition against α-Amylase (50.12 %, 33.20 %), Urease (49.12 %, 47.20 %), and Lipase (49.12 %, 42.20 %) as well as remarkable antioxidant activities (45.22 % and 52.12 %) in DPPH assay respectively. Synthesis, characterization and biological evaluation of ferrocene based schiff bases and their complexes [Display omitted]. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three Cu(II) complexes derived from halogen substituted Schiff bases were synthesized and characterized. • Antidiabetic efficacy was evaluated using α-glucose and α-amylase enzymes inhibition assay. • In vitro antibacterial, and antioxidant activity were studied on some selected bacteria and DPPH radical, respectively. • Computational and molecular docking studies were carried out. • All the complexes showed better inhibitory effect on all the assays tested. In recent years, metal-based compounds have been explored as potential remedies for major health issues such as diabetes, bacterial infections, and oxidative stress, which impact the general well-being of humans globally. Diabetes, bacterial infections, and oxidative stress are major health concerns affecting millions worldwide. Researchers have been exploring the use of metal-based compounds as potential treatments for these conditions. In our quest towards identifying biologically viable metal-based compounds, three novel Cu(II) complexes were synthesized from halogen-substituted ON donor Schiff base ligands. These ligands were obtained by condensing 2-hydroxybenzldehyde with three different halogen-substituted anilines. The ligands and their complexes were characterized using various spectroscopic techniques such as 1H and 13C nuclear magnetic resonance, Fourier Transform-Infrared, Ultraviolet–visible spectra, elemental analysis, mass spectrometry, and single-crystal X-ray spectroscopy to elucidate their structures. The compounds were screened for antidiabetic (α-glucose and α-amylase enzymes inhibition assay), antioxidant (2,2-diphenyl-1-picrylhydrazyl(DPPH), ferric reducing antioxidant potential (FRAP) assay, and nitric oxide(NO) radical scavenging), and antimicrobial activities. The pharmacological activity revealed that the efficacy of the ligands was enhanced upon coordination, and CuL3 is more potent among the complexes, having higher inhibition activity on α-glucosidase (IC 50 = 100.1 μM) than the control, whose IC 50 is 112.4 μM on the same enzyme. For radical scavenging activity, the results showed that the complexes have higher scavenging activity on DPPH radicals than their ligands and the control. For the FRAP assay, the complexes show higher activity than their ligands. Similarly, NO radical scavenging activity results indicate the ligands have higher activity than their complexes, while the complexes outperformed the control at all concentrations tested. The In vitro antibacterial results on some selected Gram-positive and Gram-negative bacteria revealed the complexes have higher antibacterial activity than their corresponding ligands, with CuL3 taking the lead, showing a MIC value of 4 g/mL on some of the bacteria tested. Also, density functional theory calculations at different levels of DFT and basis sets were used to investigate the optimized geometry, electronic structure (energy of HOMO and LUMO, Mulliken atomic charge, dipole moment, hardness, and softness, electrophilicity, and spectral properties) of the synthesized compounds. Molecular docking studies were carried out to investigate the binding affinity of the receptor proteins to other proteins and to establish the mechanism of action at the active sites. [ABSTRACT FROM AUTHOR]

In this research article, the synthesis, structural characterization, and biological, DNA binding and anticancer properties of pyrimidine incorporated Schiff base ligand L and its [CuL2](ClO4)2 (1) and [ZnL2](ClO4)2 (2) complexes are reported. The isolated complexes 1 and 2 have significant antibacterial and antifungal properties, greater than those of ligand L. The interaction between protein and L were analyzed by an in silico method. The intercalative binding of the prepared compounds was proved from electronic absorption, fluorometric, cyclic voltammetric and viscometric methods. The calculated binding parameters such as, Kb (2.65×103, L; 7.74×103, 1 and 2.99×103, 2); Ksv (3.30×103, L; 4.31×103, 1 and 3.89×103, 2), and Kapp (2.15×105, L; 3.30×105, 1 and 2.82×105, 2) indicted that complex 1 has better interaction ability than L and complex 2. The in vitro anticancer properties of L, and complexes 1 and 2 against human cancer (MCF-7, HeLa and HEp-2) and normal (NHDF) cell lines were determined by the MTT assay method. The obtained results designated that complexes 1 and 2 exhibited substantial anticancer activity against the cancer cell lines, better than that of L. [ABSTRACT FROM AUTHOR]

A selected solid complex of the Schiff base ligand derived from Glutaric anhydride with Cu(II) ion was synthesized and characterized by FT-IR, Electronic, ESR Spectral Analyses, Magnetic susceptibility and Molar Conductance Measurements. The disappearance of ν(O-H) hydroxyl band of the phenolic and the lowering shift of the stretching frequency of the ν(CH=N) azomethine band in the ligand after complexation, indicated the coordination through the phenolic oxygen atom (after deprotonation) and azomethine nitrogen atom respectively of the Schiff base ligand. The lower values of molar conductance indicate the non-electrolytic nature of these complex. The ESR spectrum of the Copper complex has octahedral geometry. The Schiff base ligand and its complex further identified by ¹H NMR, 13C NMR, SEM, EDX and molecular docking study. The anticancer potential of the Copper (II) complex was determined against A549 lung cancer cells, they exhibited appreciable anticancer activity. The in vitro cytotoxicity of the complex was examined against cancer cell line by MTT assay. The Schiff base Cu (II) complex was tested its cytotoxicity and found that the 50 percentage of activity inhibitory concentration (IC50) value around 91.25 percentage in 7.8 μg/ml. [ABSTRACT FROM AUTHOR]

Two novel Schiff base ligands, 2; 2'-((pentane-2,4-diylidene)bis(azanylylidene))bis(4-chlorophenol) and 2; 2'- ((pentane-2,4-diylidene)bis(azanylylidene))bis(4-methylphenol) were prepared by condensation reaction of acetylacetone with 2-amino-4-chlorophenol and 2-amino-4-methylphenol, respectively. Mononuclear Cu(II) complex of each ligand was also synthesized. These compounds were characterized by elemental analyses, inductively coupled plasma optical emission spectrometry, the Fourier transform infrared spectra, UV-Vis, molar conductivity, and magnetic susceptibility measurements. The ligands have been further characterized by ¹H- and 13C-NMR. The results suggest that the metal complexes of the ligands have a metal:ligand ratio of 1:1 and the Cu(II) ions are coordinated by the phenolic oxygen atoms and imine nitrogen atoms of the ligands. Moreover, the quantum chemical calculations of the compounds have been performed using the density functional theory. It has been found that the calculated spectroscopic values are in a good agreement with experimental data. [ABSTRACT FROM AUTHOR]

[Display omitted] • In this study, two chiral ligands and theirs Pd(II), Ni(II), Fe(II) and Cu(II) complexes have been synthesized and identified. • All the compounds were characterized by physical measurements, as well as spectroscopic techniques. • The cytotoxic effects of all synthesized compounds on the viability of colon cancer cells (DLD-1), breast cancer cells (MDA-MB-231) and healthy lung human cell lines were investigated by using the MTT method in vitro. • Compound L1-Pd(II) is the structure that exhibits the highest anticancer activity. • The experimental data has been supported and illuminated using computational visual methods and molecular docking, and the findings produced indicate compatibility. In this study, two chiral Schiff base ligands (L1 and L2) were synthesized from the condensation reaction of (S)-2-amino-3-phenyl-1-propanol with 2-hydroxybenzaldehyde and 2-hydroxy-1-naphthaldehyde as metal precursors for the preparation of transition metal complexes with Pd(II), Fe(II), Ni(II) and Cu(II). The compounds were characterized by using X-ray (for L1-Pd(II)), NMR, FT-IR, UV–Vis, magnetic susceptibility, molar conductivity, and elemental analysis. The in vitro cytotoxic effects of ligands (L1 and L2) and their metal complexes on colon cancer cells (DLD-1), breast cancer cells (MDA-MB-231) and healthy lung human cell lines were investigated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5‑diphenyl tetrazolium bromide (MTT) assay. Among the synthesized compounds, L1-Pd(II) was particularly found to be the most potent anticancer drug candidate in this series with IC 50 values of 4.07, and 9.97 µM in DLD-1 and MDA-MB-231 cell lines, respectively. In addition, molecular docking results indicate that Glu122, Asn103, Ala104, Lys126, Phe114, Leu123, and Lys126 amino acids are the binding site of the colon cancer antigen protein, in which the most active complex, L1-Pd(II) can inhibit the current target. [ABSTRACT FROM AUTHOR]

Twelve copper(II) Schiff base complexes derived from lipophilic amines have been prepared using either salicylaldehyde or ortho-vanillin via a microwave-assisted reaction. All complexes have been obtained elementally pure and an X-ray diffraction of an isopentyl derivative has confirmed the structure of these compounds. All complexes showed a promising degree of anti-mycobacterial activity against Mycobacterium tuberculosis, where activity seemed to increase with an increase in the length of the aliphatic chain. [ABSTRACT FROM AUTHOR]

Highlights: [•] Galectin-3 expression induces apoptosis in melanoma cells treated with [Cu(isaepy)]. [•] The mechanisms involved in melanoma apoptosis include ROS formation and p38 activation. [•] The isatin-Schiff base-copper (II) complex may be envisaged as a possible anti-melanoma strategy, particularly for melanomas that express galectin-3. [Copyright &y& Elsevier]

Synthesis and characterization of some new Schiff base ligands derived from various diamines and nitrosalicylaldehyde and their complexes of Ni(II) and Cu(II) are reported. Several spectral techniques such as UV-Vis, FT-IR, and NMR spectra were used to identify the chemical structures of the reported ligands and their complexes. The ligands are found to be bound to the metal atom through the oxygen atoms of the hydroxyl groups and nitrogen atoms of imine groups, which is also supported by spectroscopic techniques. The results obtained by FT-IR and NMR showed that the Schiff base complexes of transition metal (II) have square-planar geometry. [ABSTRACT FROM AUTHOR]

A series of Co(II), Ni(II), and Cu(II) complexes of the type ML.2H2O have been synthesized with Schiff bases derived from 8-formyl-7-hydroxy-4-methylcoumarin and o-phenylenediamine/ethylenediamine. The structure of the complexes has been proposed in the light of analytical, spectral (IR, UV-Vis, ESR, and FAB-mass), magnetic, thermal, and fluorescence studies. The complexes are soluble in DMF and DMSO. The measured molar conductance values indicate that the complexes are non-electrolytes in nature. In view of IR, UV-Vis, and magnetic studies, it has been concluded that all the complexes possess octahedral geometry, in which ligand is coordinated to metal ion through the azomethine nitrogen and phenolic oxygen via deprotonation. Thermal studies provide useful information about the coordination of water molecules to the metal ion and the stability of the complexes. The redox behavior of the complexes has been investigated by an electrochemical method using cyclic voltammetry. The Schiff bases and their metal complexes have been screened for their antibacterial ( Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella typhi) and antifungal activities ( Aspergillus niger, Aspergillus flavus, and Cladosporium) by the minimum inhibitory concentration method. DNA binding with Co(II) and Cu(II) complexes has been studied by the agarose gel electrophoresis method. [ABSTRACT FROM AUTHOR]

Recently, we have discovered that some chiral Schiff-base nickel(II) complexes induced d-d bands of CD spectra of some achiral copper(II) complexes. However, the novel phenomenon could be observed only a few systems of hybrid materials or limited conditions so far. In order to test conditions about copper(II) ions, we investigated model systems (1) metal-dendrimer (Cu- PAMAM; G4-NH2 terminal) containing relatively small amount of copper(II) ions (4.5 equivalent to PAMAM) for modeling separated systems of achiral copper(II) complex from chiral Schiff-base nickel(II) or zinc(II) complexes, Bis(N-R-1-naphtylethyl- 3,5-dichlorosalicydenaminato)nickel(II) or zinc(II) by polymer matrix. (2) equilibrium of copper(II) N-ethylethylenediamine complexes to measure absorption spectra of d-d band, pH, and electron conductivity during titration of copper(II) ions. The results showed that (1) 4.5Cu-PAMAM could not be induced their d-d bands by the chiral nickel(II) or zinc(II) complexes, which suggested that separation by polymers prevented from inducing CD peaks. (2) Although 36Cu-PAMAM was known, uncoordinated copper(II) ions excess to ligands mainly attributed to increase electron conductivity by remained ions in methanol solutions, which was not associated with intermolecular interaction or dipole moments being effective for the induced CD mechanism by using molecular recognition between neutral molecules of metal complexes. [ABSTRACT FROM AUTHOR]

Condensation of salicylaldehyde (2-HOC6H4C(O)H) with 5-aminosalicylic acid (5-H2NC6H3-2-(OH)-CO2H) afforded the Schiff base 2-HOC6H4C(H)=NC6H3-2-(OH)-5-CO2H (a). Similar reactivity with 5-bromosalicylaldehyde was also observed to give 5-Br-2-HOC6H3C(H)=NC6H3-2-(OH)-5-CO2H (b). Reaction of these salicylaldehydes with Pd(II), Cu(II), and Zn(II) salts gave the corresponding bis(N-arylsalicylaldiminato)metal complexes (M = Pd (1), Cu (2), Zn (3)). The molecular structure of the Schiff base compound a has been confirmed by an X-ray diffraction study. Crystals of a were monoclinic, space group P2(1)/c, a = 7.0164(7) Å, b = 11.0088(11) Å, c = 14.8980(15) Å, β = 102.917(2)°, Z = 4. The molecular structure of a novel zwitterionic conformer of 3a was also characterized by an X-ray diffraction study. Crystals of 4 were monoclinic, space group P2(1)/c, a = 9.5284(5) Å, b = 19.5335(11) Å, c = 8.6508(5) Å, β = 90.596(1)°, Z = 4. All new compounds have been tested for their antifungal activity against Aspergillus niger and Aspergillus flavus. [ABSTRACT FROM AUTHOR]

We have investigated linearly polarized UV light-induced molecular orientation due to Weigert effect of composite materials of new six binuclear nickel(II), copper(II), and zinc(II) complexes of two rigid Schiff base ring ligands (L1 and L2) composite materials with methyl orange (MO), an azo-dye, in polyvinylalchol (PVA) cast films. To compare the degree of molecular orientation, two ligands, namely flexible aliphatic cyclohexane (ML1: NiL1, CuL1, ZnL1) and rigid aromatic (ML2: NiL2, CuL2, ZnL2), were synthesized using amine moiety. We have also characterized these complexes by means of elemental analysis, IR, and UV-vis spectra, single crystal or powder X-ray diffraction (XRD) analysis, and so on. Composite materials of ML1 or ML2+MO+PVA were also prepared to separately disperse the solutes in a polymer matrix. For any metal complexes, optical anisotropy (represented as the R parameters) of ML2+MO+PVA was larger than ML1+MO+PVA because of the rigidness of the ligands. [ABSTRACT FROM AUTHOR]