Zn Chelates Research Articles

Vascular protection afforded by zinc supplementation in human coronary artery smooth muscle cells mediated by NRF2 signaling under hypoxia/reoxygenation

Zinc (Zn) has antioxidant, anti-inflammatory and anti-proliferative actions, with Zn dysregulation associated with coronary ischemia/reperfusion injury and smooth muscle cell dysfunction. As the majority of studies concerning Zn have been conducted under non-physiological hyperoxic conditions, we compare the effects of Zn chelation or supplementation on total intracellular Zn content, antioxidant NRF2 targeted gene transcription and hypoxia/reoxygenation-induced reactive oxygen species generation in human coronary artery smooth muscle cells (HCASMC) pre-adapted to hyperoxia (18 kPa O2) or normoxia (5 kPa O2). Expression of the smooth muscle marker SM22-α was unaffected by lowering pericellular O2, whereas calponin-1 was significantly upregulated in cells under 5 kPa O2, indicating a more physiological contractile phenotype under 5 kPa O2. Inductively coupled plasma mass spectrometry established that Zn supplementation (10 μM ZnCl2 + 0.5 μM pyrithione) significantly increased total Zn content in HCASMC under 18 but not 5 kPa O2. Zn supplementation increased metallothionein mRNA expression and NRF2 nuclear accumulation in cells under 18 or 5 kPa O2. Notably, NRF2 regulated HO-1 and NQO1 mRNA expression in response to Zn supplementation was only upregulated in cells under 18 but not 5 kPa. Furthermore, whilst hypoxia increased intracellular glutathione (GSH) in cells pre-adapted to 18 but not 5 kPa O2, reoxygenation had negligible effects on GSH or total Zn content. Reoxygenation-induced superoxide generation in cells under 18 kPa O2 was abrogated by PEG-superoxide dismutase but not by PEG-catalase, and Zn supplementation, but not Zn chelation, attenuated reoxygenation-induced superoxide generation in cells under 18 but not 5kPaO2, consistent with a lower redox stress under physiological normoxia. Our findings highlight that culture of HCASMC under physiological normoxia recapitulates an in vivo contractile phenotype and that effects of Zn on NRF2 signaling are altered by oxygen tension.

Physiological and biochemical responses to caffeine and microplastics in Mytilus galloprovincialis

Caffeine (Caff) is one of the most widely used substances in the human diet and a well-recognized drug. Its input into surface waters is remarkable, but biological effects on aquatic organisms are unclear, particularly in combination with pollutants of suspected modulatory activity, like microplastics (MP). The aim of this study was to reveal the impact on the marine mussel Mytilus galloprovincialis (Lamark, 1819) of Caff (20.0 μg L−1) in the environmentally relevant combination (Mix) with MP 1 mg L−1 (size 35–50 μm) after the exposure for 14 days. Untreated and exposed to Caff and MP separately groups were also examined. Cell viability and cell volume regulation in hemocytes and digestive cells, as well as the indexes of oxidative stress, glutathione (GSH/GSSG) and metallothioneins levels, and caspase-3 activity in digestive gland were assessed. MP and Mix reduced Mn-superoxide dismutase, catalase, and glutathione S-transferase activities and level of lipid peroxidation, but increased the digestive gland cell viability, GSH/GSSG ratio (by 1.4–1.5-fold), metallothioneins level and their Zn content, while Caff did not affect oxidative stress indexes and metallothionein-related Zn chelation. Protein carbonyls were not targeted in all exposures. The distinguishing feature of the Caff group was the decline (2-fold) in caspase-3 activity and low cell viability. The multi-stress effect of Mix was shown by the worsening of the volume regulation of digestive cells and confirmed by discriminant analysis of biochemical indexes. The special capabilities of M. galloprovincialis as a sentinel organism make it an excellent bio-indicator reflecting the multi-stress effects in sub-chronic exposures to potentially harmful substances. The identification of the modulation of individual effects in combined exposure increases the need to base monitoring programs on studies of multi-stress effects in sub-chronic exposures.

Bivalent Metal Chelates with Pentadentate Azo-Schiff Base Derived from Nicotinic Hydrazide: Preparation, Structural Elucidation, and Pharmacological Activity.

Azo-Schiff base ligand (N'-((E)-2-hydroxy-5-((E)-(2-hydroxyphenyl)diazenyl)benzylidene)nicotinohydrazide) and its Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Pd(II) chelates were prepared and elucidated. The geometrical structures of the prepared chelates were characterized by several spectroanalytical techniques and thermogravimetric analysis. The obtained data revealed that the chelates have (1M:1L), (1M:2L), (1M:3L), and (1M:4L) molar ratios. The infrared spectra displayed that the H2 L ligand behaves in a pentacoordinate fashion in chelates of Mn(II), Ni(II), and Cu(II) ions. However, in Zn(II) and Pd(II) chelates, the ligand is coordinated as a tetradentate species (NONO) through nitrogen atoms of azomethine and azo groups as well as oxygen atoms of phenolic hydroxy, and carbonyl groups. Besides, it was concluded that the oxygen atoms of carbonyl and hydroxy groups along with the azomethine nitrogen atom of the ligand are bounded with Co(II) ion in metal chelate (2). According to the measured molar conductance values, the chelates of Cu(II), Zn(II), and Pd(II) are weak electrolytes, but Mn(II), Co(II), and Ni(II) chelates are ionic. The azo-Schiff base ligand and its prepared metal chelates were tested for their antioxidant and antibacterial properties. The Ni(II) chelate was found to be considered an effective antioxidant agent. In addition, the available antibacterial data suggest that the Ni(II) and Co(II) chelates may be employed as inhibitor agents against Proteus vulgaris, Escherichia coli, and Bacillus subtilis bacteria. Furthermore, the data showed that, in comparison to the ligand and other metal chelates, copper(II) chelate (4) exhibited higher action against Bacillus subtilis bacteria.

Calcination-dependent microstructural and optical characteristics of eco-friendly synthesized ZnO nanoparticles and their implementation in analog memristor application

Using Camellia Sinensis leaf aqueous extract as a friendly reducing, capping, and stabilizing agent, ZnO nanoparticles (NPs) are synthesized via the green process. The plausible mechanism for the ZnO NPs formation is proposed as the chelation of Zn, or metal complexation, under the thermally assisted energy from the annealing process. An inclusive study on the effect of the annealing process on the ZnO NPs is conducted from room temperature to 850 °C. The structural, morphological, thermal, and optical characteristics and their intercorrelation with annealing temperature are thoroughly studied. In particular, the change of crystalline texture coefficient contributed to the systematic perspective of the shape changes of the ZnO NPs. The (002)-oriented growth becomes preferred at 400–700 °C, corresponding to the increase of conical-shaped NPs from 150 to 250 nm in average size. With further temperature, the preferred growth transfers from (002) to (100) orientations, and polygonal spherical-shaped NPs can be obtained. Photoluminescence spectra reveal that singly and doubly ionized oxygen vacancies are the most dominant in the NPs. With the optimized green materials, implementing an eco-friendly memristor based on ZnO NPs found promising for electronic devices.

A resonant energy transfer electrochemiluminescence immunosensor based on low trigger potential of Zn-metal organic framework and CoOOH nanosheets for 5-fluorouracil detection

The organic luminophores have inspired widespread interest in electrochemiluminescence (ECL). Herein, a novel rod-like metal-organic framework was formed by chelating Zn ion with 9,10-di(p-carboxyphenyl)-anthracene (DPA), defined as Zn-MOF for simplicity. In this proposal, the prepared Zn-MOF was first used as a powerful organic luminophore with low trigger potential, thus developing a competitive ECL immunoassay for ultrasensitive detection of 5-fluorouracil (5-FU) with 1,4-diazabicyclo[2.2.2]octane (D-H2) as the coreactant. The absorption spectrum of cobalt oxyhydroxide (CoOOH) nanosheets and the ECL emission spectrum of Zn-MOF could be highly matched, which ensured the occurrence of resonance energy transfer (RET). For that, ECL-RET was applied in the assembly strategy of the ECL biosensor, and Zn-MOF was used as the energy donor and CoOOH nanosheets as the acceptor. Taking advantage of the luminophore and ECL-RET, the immunoassay can be used for ultra-sensitive quantitative detection of 5-fluorouracil. The proposed ECL-RET immunosensor showed satisfactory sensitivity and accuracy with a wider linear range from 0.001 to 1000 ng/mL, and a lower detection limit (0.52 pg/mL). Hence, it is worth believing that this strategy can pave a bright research direction for the detection of 5-FU or other biological small molecules.

Anti-corrosive agents based benzil-thiocarbohydrazone macrocyclic ligand-derived Cu (II) and Zn (II) chelates: template synthesis and physically admixing with epoxy coating

PurposeThis paper aims to focus on the synthesis of the macrocyclic complexes (Cu and Zn) and their applications as anticorrosive materials in epoxy paint formulation for surface coating application.Design/methodology/approachA selected macrocyclic Cu(II) and Zn(II) complexes were prepared via template synthesis and characterized using Fourier transform infrared, thermal gravimetric analysis, scanning electron microscope, flexibility, hardness and adhesion of coating films prepared using epoxy paint.FindingsThe corrosion resistance of the epoxy-painted films was improved due to the incorporation of the Zn and Cu complexes into the formulation.Originality/valueIt was found that the metal complex-based formulation with Cu(II) and Zn(II) had outperformed the sample blank.

Preparation of Zn-Gly and Se-Gly and Their Effects on the Nutritional Quality of Tea (Camellia sinensis).

Micronutrient malnutrition affects millions of people due to a lack of Zn and Se. The process conditions for the manufacture of glycine-chelated sodium selenite (Se-Gly) and zinc sulfate heptahydrate (Zn-Gly) were studied. The effects of ligand concentration, pH, reaction ratio, reaction temperature, and reaction time on fertilizer stability were assessed. The effects of Zn-Gly and Se-Gly on tea plants were determined. Orthogonal experiments showed that the optimal preparation conditions for Zn-Gly (75.80 % Zn chelation rate) were pH 6.0, ligand concentration 4 %, reaction ratio 1:2, reaction time 120 min, reaction temperature 70 ℃. The optimal preparation conditions for Se-Gly (56.75 % Se chelation rate) were pH 6.0, ligand concentration 10%, reaction ratio 2:1, reaction time 40 min, temperature 50 ℃. Each chelate was completely soluble in water and verified by infrared spectroscopy and ultraviolet spectroscopy. Zn-Gly and Se-Gly increased the Zn and Se content in tea plants, and foliar application was more effective than soil application. Combined application of Zn-Gly and Se-Gly was more effective than Zn-Gly or Se-Gly alone. Our findings suggest that Zn-Gly and Se-Gly provide a convenient method of addressing human Zn and Se deficiency.

An optical keypad lock with high resettability based on a quantum dot-porphyrin FRET nanodevice.

Due to their appealing properties, nanomaterials have become ideal candidates for the implementation of computing systems. Herein, an optical keypad lock based on a Förster resonance energy transfer (FRET) nanodevice is developed. The nanodevice is composed of a green-emission quantum dot with a thick silica shell (gQD@SiO2) and peripheric blue-emission quantum dots with ultrathin silica spacer (bQD@SiO2), on which 5,10,15,20-tetrakis(4-sulfophenyl)porphyrin (TSPP) is covalently linked. The nanodevice outputs dual emission-based ratiometric fluorescence, depending on the FRET efficiency of bQD-porphyrin pairs, which is highly sensitive to the metalation of TSPP: values are 59.7%, 44.8%, and 10.1% for bQD-Zn(ii)TSPP, bQD-TSPP, and bQD-Fe(iii)TSPP pairs, respectively. As such, by using the competitive chelation-induced transmetalation of TSPP, the nanodevice is capable of implementing a 3-input keypad lock that is unlocked only by the correct input order of Zn(ii) chelator, iron ions, and UV light. Interestingly, the reversible transmetalation of TSPP permits the reset (lock) operation of the keypad lock with the correct input order of ascorbic acid, Zn(ii), and UV light. Application of the nanodevice is exemplified by the construction of paper and cellular keypad locks, respectively, both of which feature signal readability and/or high resettability, showing high potential for personal information identification and bio-encryption applications.

Depletion of Zinc Causes Osteoblast Apoptosis with Elevation of Leptin Secretion and Phosphorylation of JAK2/STAT3.

Zinc (Zn) has been reported to mediate leptin secretion, and thus leptin can be an important candidate molecule linking Zn with bone formation. The present study investigated whether zinc deficiency induces leptin secretion by activating a JAK2/STAT3 signaling pathway and leads to osteoblastic apoptosis. MC3T3-E1 cells were incubated for 24 h in normal osteogenic differentiation medium (OSM) or OSM treated with either 1 μM (Low Zn) or 15 μM (High Zn) of ZnCl2 containing 5 μM TPEN (Zn chelator). Our results demonstrated that low Zn stimulated extracellular leptin secretion and increased mRNA and protein expression of leptin in osteoblastic MC3T3-E1 cells. The OB-Rb (long isoform of leptin receptor) expressions were also elevated in osteoblasts under depletion of Zn. Leptin-signaling proteins, JAK2 and p-JAK2 in the cytosol of low Zn osteoblast conveyed leptin signaling, which ultimately induced higher p-STAT3 expression in the nucleus. Apoptotic effects of JAK2/STAT3 pathway were shown by increased caspase-3 in low Zn osteoblasts as well as apoptotic morphological features observed by TEM. Together, these data suggest that low Zn modulates leptin secretion by activating JAK2/STAT3 signaling pathway and induces apoptosis of osteoblastic MC3T3-E1 cells.

WPŁYW DODATKU CHELATÓW CU I ZN NA ZAWARTOS´ C TYCH PIERWIASTKÓW W KRWI KURCZ ˛AT ´ BROJLERÓW ORAZ NA ICH MAS ˛E CIAŁA I KONWERSJ ˛E PASZY

The aim of the study was to determine the effect of Cu and Zn chelates on the levels of these microelements in the blood of broiler chickens in successive weeks of rearing. The re-search material was Ross 308 broiler chickens. The study was carried out in two buildings with 30,000 chickens in each. From each building, 50 chickens were randomly selected to form the experimental and control groups. Blood for analysis was collected from the wing vein every 7 days, from the first day of fattening to day 42. In the experimental group the microelements zinc and copper contained in the feed were in organic form. The effect of the feed additive containing selected microelements in organic form on broiler chickens was assessed from weeks 1 to 6 of fattening. During the experiment the average body weight gains were monitored. Mortality was monitored, and feed consumption per kg weight gain was estimated. To conclude, the addition of organic Cu and Zn chelates to the diet of broiler chickens affected their average body weight gain, increasing body weight at the start and end of the fattening period (fifth and sixth weeks of age) while increasing feed conversion.

Preparation and Characterization of Ginger Peel Polysaccharide-Zn (II) Complexes and Evaluation of Anti-Inflammatory Activity.

The present study aimed to explore the improvement of the bioactivity of ginger peel polysaccharides (GPs) by the modification of zinc after structural characterization. The obtained GP-Zn (II) complexes consisted dominantly of glucose and galactose in a mass proportion of 95.10:2.10, with a molecular weight of 4.90 × 105 Da and a Zn content of 21.17 mg/g. The chelation of GPs and Zn (II) was mainly involved in the O-H of hydroxyl groups, and this interaction reduced the crystallinity and decreased the asymmetry of GPs, with a slight effect on the thermal stability. The administration of GPs and their Zn (II) complexes effectively alleviated CuSO4-induced inflammatory response in zebrafish (Tg: zlyz-EGFP) via down-regulating the mRNA expression levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-12 and TNF-α) and upregulating the expression of anti-inflammatory cytokine (IL-10). Furthermore, the modification of Zn (II) enhanced the inflammation-inhibiting effect of polysaccharides. Therefore, GP-Zn (II) complexes could be applied as a candidate anti-inflammatory agent for the treatment of chronic inflammation-related diseases.

A Turn-Off Fluorescent Strategy for Calprotectin Detection Based on the Inhibitory Effect of Calprotectin upon the Activity of Zn(Ⅱ)-Dependent DNAzyme

Calprotectin (CP) is an established biomarker that allows the noninvasive evaluation of inflammation levels in the gastrointestinal tract of patients with inflammatory bowel disease and is helpful for the diagnosis and management of the disease. Herein, we demonstrate that CP can effectively suppress the activity of 17E DNAzyme (17E) by chelating Zn(Ⅱ), which is the cofactor of 17E. As the inhibition efficiency of CP on the DNAzyme is proportional to the concentration of CP, the detection of CP can be readily achieved by assessing the activity of 17E.

Fluorescence, cyclic voltammetric, computational, and spectroscopic studies of Mn(II), Co(II), Pd(II), Zn(II) and Cd(II) complexes of salen ligand and their biological applications

2,2′-((1E,1′E)-(ethane-1,2-diylbis(azanylylidiene))bis(methanylylidene))diphenol (H2L) ligand and its Mn(II), Co(II), Pd(II) Zn(II) and Cd(II) chelates have been isolated and characterized by conventional and spectroscopic techniques including FTIR spectrum, 1HNMR , 13CNMR , powder X-ray diffraction [PXRD], UV–visible, mass spectroscopy besides elemental analyses, and magnetic susceptibility measurements. The DMOL3 tool in the material studio package was also used to optimize the structures. The ligand behaves as binegative N2O2 tetradentate in Pd(II) and Zn(II) complex, neutral N2 bidentate in Mn(II), Co(II) and Cd(II)-complexes. Horowitz–Metzger and Coats–Redfern approaches were used to estimate the various kinetic and thermodynamic parameters. Zeta Potentials for the H2L ligand and its Pd(II), Cd(II) and Co(II) complexes in ethanol as a dispersive medium were measured. Ligand and its complexes were tested for their biological potency as anti-bacterial activity against gram (-) E. coli, P. aeruginosa, and gram (+) B. subtilis, S. aureus bacteria as well as antifungal activity against C. albicans. The antioxidant potentials of the isolated compounds were also screened by using DPPH scavenging methods. The isolated compounds were examined for cytotoxic activity using the MTT assay on MDA-MB-231 and HepG2 cell lines, and the results were verified using molecular docking simulations.

The Zinc Ionophore Clioquinol Reduces Parkinson's Disease Patient-Derived Brain Extracts-Induced Neurodegeneration.

Parkinson's disease (PD) is pathologically characterized by intracellular α-synuclein-rich protein aggregates, named Lewy bodies (LB), and by the progressive loss of dopaminergic neurons in the substantia nigra. Several heavy metals, including zinc (Zn), have been suggested to play a role in PD progression, although the exact role of Zn in neurodegeneration remains to be fully elucidated. To address this gap, we investigated the effects of Zn modulation on the progression of degeneration in mice injected with PD patient-derived LB-extracts carrying toxic α-synuclein aggregates. Zn modulation was achieved using either a clioquinol-enriched diet, a Zn ionophore that redistributes cellular Zn, or a Zn-enriched diet that increases Zn levels. Clioquinol treatment significantly prevented dopaminergic neurodegeneration and reduced α-synuclein-associated pathology in LB-injected mice, while no differences were observed with Zn supplementation. Biochemical analyses further demonstrate that the expression levels of vesicle-specific Zn transporter ZnT3 in the striatum of LB-injected mice treated with clioquinol were decreased, suggesting an intracellular redistribution of Zn. Additionally, we found that clioquinol modulates the autophagy-lysosomal pathway by enhancing lysosomal redistribution within the neuronal compartments. Collectively, we found that in vivo pharmacological chelation of Zn, by dampening Zn-mediated cytotoxicity, can result in an overall attenuation of PD-linked lysosomal alterations and dopaminergic neurodegeneration. The results support zinc chelation as a disease-modifying strategy for treating PD.

Zinc transport from the endoplasmic reticulum to the cytoplasm via Zip7 is necessary for barrier dysfunction mediated by inflammatory signaling in RPE cells.

Inflammatory signaling induces barrier dysfunction in retinal-pigmented epithelium (RPE) cells and plays a role in the pathology of age-related macular degeneration (AMD). We studied the role of Zn flux from the endoplasmic reticulum (ER) to the cytoplasm via Zip7 during inflammatory signaling in RPE cells. In ARPE-19 cells, Zip7 inhibition reduced impedance loss, FITC-dextran permeability and cytokine induction caused by challenge with IL-1β/TNF-α. Zip7 inhibition in iPS-derived RPE cells challenged with TNF- α reduced barrier loss in TER assays. In ARPE-19 cells, a Zn ionophore restored cytokine induction and barrier loss in cells challenged with IL-1 β /TNF- α despite Zip7 inhibition. A cell permeable Zn chelator demonstrated that Zn is essential for IL-1 β /TNF- α signaling. ER stress caused by Zip7 inhibition in ARPE-19 cells was found to partially contribute to reducing barrier dysfunction caused by IL-1 β /TNF- α. Overall, it was shown that Zn flux through Zip7 from the ER to the cytoplasm plays a critical role in driving barrier dysfunction caused by inflammatory cytokines in RPE cells.

Synthesis, spectroscopic, DFT calculations, antimicrobial, cytotoxicity, and DNA binding studies of novel Cu (II), Ni (II), Zn (II), and VO (II) Schiff base complexes based on ibuprofen

The ibuprofen Schiff base ligand (HL) [HL=2‐(4‐Isobutyl‐phenyl)‐propionic acid (3‐hydroxy‐naphthalen‐2‐ylmethylene)‐hydrazide] and its Cu (II), Ni (II), Zn (II), and VO (II) chelates were synthesized and characterized. The spectral data revealed that the Schiff base ligand HL coordinated to Cu (II), Ni (II), Zn (II), and VO (II) via azomethine nitrogen and phenolic oxygen. NiL and CuL have square planar geometry, ZnL has octahedral geometry, and VOL has square pyramidal geometry. Density functional calculations (DFT) were performed to examine the molecular geometry. The results of continuous variation and molar ratio methods supported the ratio of (M:L) to be (1:1). The antimicrobial activity of the new Ibuprofen Schiff base ligand and its metal complexes was tested in vitro against bacterial pathogens and fungi. The results revealed that the antimicrobial efficacy follows the order: CuL is the highly inhibitor complex compared with ketoconazole and gentamicin as reference drugs. The in vitro cytotoxic activity of the new ligand and its complexes was also investigated against Hep‐G2, MCF‐7, and HCT‐116 cell lines. The results showed again that CuL is the highest active agent compared with Vinblastine drug. The CT‐DNA binding ability of the studied complexes was evaluated by absorption spectroscopic titrations and gel electrophoresis. The results showed that the complexes have good binding propensity, and their binding constant values were from 3.1 × 105 to 6.1 × 105 M−1.

Rice growth improvement, bio-fortification, and mitigation of macronutrient requirements through foliar application of zinc and iron- glycine chelate and zinc sulfate

Foliar application of Zinc (Zn) and Iron (Fe) fertilizers is known to be an effective solution to enhance rice grain yield and bio-fortification. The objectives of the current field experiment were to evaluate the effects of the foliar application of 0.5, 1, and 1.5 kg ha−1 of Zn and Fe glycine amino acid chelates and ZnSO4 on rice grain yield, protein, Zn, and Fe content of head rice (Hashemi cultivar) under both in the recommended and ½ of the recommended dose of NPK. The highest increase in the grain yield was recorded at 0.5 kgha−1 Fe-glycine amino acid chelate by about 29.2%. The maximum increase in protein and Zn content of head rice were recorded at 1.5 kg ha−1 of glycine amino acid-Zn chelate by about 10.5 and 22.3%, respectively. The most effective treatment to enhance the Fe content of head rice was the foliar application of 1.5 kg ha−1 of glycine amino acid-Fe chelate by about 32.6%. Interestingly, the foliar application of 1 kg ha−1 Zn-glycine amino acid chelate plus 1 kg ha−1 Fe-glycine amino acid chelate at the plots that received ½ of recommended NPK increased the grain yield, and protein, Zn and Fe content of head rice compared to control by about 7%, 18.5, 7.5, and 26.2, respectively. Therefore, regardless of rates and types, foliar application of Zn and/or Fe could enhance both rice yield, protein, Zn, and Fe content of head rice both in plots that received recommended and ½ of the recommended dose of NPK.

Zinc improves antibacterial, anti-inflammatory and cell motility activity of chitosan for wound healing applications

We report the successful preparation and characterization of chitosan-Zn complex (ChiZn) in the form of films, intended to enhance the biological performance of chitosan by the presence of Zn as antibacterial agent and biologically active ion. The influence of Zn chelation on morphology and structure of chitosan was assessed by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and infrared spectroscopy. The biodegradability study of ChiZn showed a sustained release of Zn up to 2 mg/mL. No toxic response was observed toward stromal cell line ST-2 in indirect contact with the ChiZn films. The dissolution product of ChiZn showed improved wound closure (88% closure) compared to the positive control group (70% closure). Moreover, ChiZn exhibited antibacterial activity against S. aureus together with a slight increase (~30%) in the secretion of VEGF and moderate decrease in nitric oxide evolution. Our findings indicate that ChiZn could be used as a safe and effective wound healing agent.

Synthesis, characterization, biological and docking studies of ZrO(II), VO(II) and Zn(II) complexes of a halogenated tetra-dentate Schiff base

The new Schiff base ligand 2,2′-{(4-chloro-1,2-phenylene)bis(nitrilo(E)methylylidene)}bis(4-bromophenol) (H 2 L) and its VO(II), Zn(II) and ZrO(II) metal chelates have been synthesized and characterized by spectral, powder x-ray diffraction (PXRD), molar conductance, magnetic measurements, thermal and elemental analyses. The molecular geometry of the prepared compounds has been confirmed by applying the theoretical density functional theory calculations (DFT). The analytical data showed that the parent azomethine H 2 L ligand binds to the VO(II), Zn(II) and ZrO(II) ions through both of the two azomethine-N and two phenolic-O groups and adopts distorted octahedral geometry for ZnL(H 2 O) 2 chelate while square pyramidal geometries for VOL and ZrOL chelates. The antioxidant activity of the compounds was also evaluated by using 1,1‐diphenyl‐2‐picrylhydrazyl (DDPH) reduction method and compared with the positive control ascorbic acid. Carcinoma cells such as breast (MCF-7), liver (Hep-G2), colon (HCT-116) carcinoma cell lines and human embryonic kidney 293 cells (HEK-293) were used for in vitro cell proliferation to investigate the anticancer potency of the prepared compounds. The results showed that, the tumor growth is inhibited and dose-dependent according to the following order: VOL > ZrOL > ZnL(H 2 O) 2 > H 2 L. The titled compounds have been also tested for their antimicrobial activity against certain pathogenic bacteria and fungi. The results showed that the H 2 L ligand and its complexes has enhanced antibacterial and antifungal activities. The CT-DNA binding experiments of azomethine chelates showed that, the binding modes are intercalative, and the determined intrinsic binding constants (K b ) for the VOL, ZrOL, ZnL(H 2 O) 2 complexes, are in the range 6.1–7.8 × 10 5 mol −1 dm −3 . The docking calculations were performed to probe the nature of binding affinity of the synthesized compounds with human DNA (PDB:1bna). The compounds may be applicable orally in an accurate manner, according to their in-silico intake, delivery, metabolic processes, digestion, and toxic effects (ADME) data.

Synthesis and characterization of bis-tridentate group 12 perchlorate complexes of bis(2-pyridylmethyl) ether

Bis-tridentate chelates of Zn(ClO4)2, Cd(ClO4)2, and Hg(ClO4)2 with two equivalents of bis(2-pyridylmethyl) ether (L1) were isolated. The complexes were characterized using X-ray crystallography, IR, 1H NMR, and TGA. Isomorphs [Zn(L1)2](ClO4)2·CH3CN (1·CH3CN) and [Cd(L1)2](ClO4)2·CH3CN (2·CH3CN) crystallized in the monoclinic space group P21 with meridional octahedral geometry. [Hg(L1)2](ClO4)2 (3) crystallized in the monoclinic space group P21/c with approximately C2 symmetric trigonal prismatic geometry. Proton NMR of 3 at −40 °C revealed heteronuclear JHgH coupling yet lacked the geminal splitting of methylene protons expected from the solid-state structure suggesting equivalence through intramolecular reorganization was rapid relative to the NMR time scale. The complexes are compared to other bis-tridentate chelates of bis(2-pyridylmethyl) ligands with the central oxygen of L1 replaced by other heteroatoms.