Metal Ions Zn Research Articles

Cellulose induced protein 1 (Cip1) from Trichoderma reesei enhances the enzymatic hydrolysis of pretreated lignocellulose

BackgroundTrichoderma reesei is currently the main strain for the commercial production of cellulase. Cellulose induced protein 1 (Cip1) is one of the most abundant proteins in extracellular proteins of T. reesei. Reported literatures about Cip1 mainly focused on the regulation of Cip1 and its possible enzyme activities, but the effect of Cip1 on the enzymatic hydrolysis of lignocellulose and possible mechanism have not still been reported.ResultsIn this study, Cip1 from T. reesei was cloned, expressed and purified, and its effects on enzymatic hydrolysis of several different pretreated lignocellulose were investigated. It was found that Cip1 could promote the enzymatic hydrolysis of pretreated lignocellulose, and the promoting effect was significantly better than that of bovine serum albumin (BSA). And especially for the lignocellulosic substrate with high lignin content such as liquid hot water pretreated corn stover and corncob residue, the promoting effect of Cip1 was even better than that of the commercial cellulase when adding equal amount protein. It was also showed that the metal ions Zn2+ and Cu2+ influenced the promoting effect on enzymatic hydrolysis. The Cip1 protein had no lyase activity, but it could destroy the crystal structure of cellulose and reduce the non-productive adsorption of cellulase on lignin, which partly interpreted the promoting effect of Cip1 on enzymatic hydrolysis of lignocellulose.ConclusionThe Cip1 from T. reesei could significantly promote the enzymatic hydrolysis of pretreated lignocellulose, and the promotion of Cip1 was even higher than that of commercial cellulase in the enzymatic hydrolysis of the substrates with high lignin content. This study will help us to better optimize cellulase to improve its ability to degrade lignocellulose, thereby reducing the cost of enzymes required for enzymatic hydrolysis.

Spectroscopic studies, DFT calculations, thermal analysis, anti-cancer evaluation of new metal complexes of 2-hydroxy-N-(4-phenylthiazol-2-yl)benzamide

2-Hydroxy-N-(4-phenylthiazol-2-yl)benzamide was reacted with Cr(III), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Ag(I) metal ions to synthesize the corresponding coordination compounds. From the study, 2-hydroxy-N-(4-phenylthiazol-2-yl)benzamide was rearranged to 2-hydroxy-N-(4-phenyl-1,3-thiazole-2-yl)carboxymidic acid (HL) due to the keto-enol tautomeric forms, where the enol form is more dominant. The structures of the HL ligand and the newly synthesized coordination compounds have been characterized by elemental analysis, IR, UV-Visible, 1H NMR, ESR and mass spectral data, in addition to thermal gravimetric analysis (TGA) and magnetic and molar conductance measurements. The ligand behaves as a monobasic bidentate ON sites, where the bidentate binding of the ligand involving the phenolic oxygen and azomethine nitrogen. The binding modes of the coordination compounds were further confirmed using Gaussian 09 software. The complexes of Co(II), Cu(II), Zn(II), and Ag(I) were tested in vitro against human colon carcinoma cells (HCT-116). The IC50 values showed dramatic toxicity results for cobalt(II), copper(II) and zinc(II) complexes versus human colon carcinoma (HCT-116) cell line, compared to African green monkey kidney (VERO) normal cell line. According to the results of the IC50 values obtained for Co(II), Cu(II), Zn(II), and Ag(I) 1.5, 1.0, 1.8 and 7.3 μg/ml, respectively, compared to the reference drug (2.49 μg/ml), Co(II), Cu(II), Zn(II) compounds are considered strong antitumor agent while Ag(I) compound can be considered as a weak one. For both antifungal and antibacterial activities, HL and all its coordination compounds were evaluated. HL ligand has only high activity against B. subtilis and C. albicans while Co(II) and Zn(II) compounds have the highest activity against S. aureus, P. aeruginisa, B. subtilis and E. coli.

Removal of Zn(II) and Ni(II) heavy metal ions by new alginic acid-ester derivatives materials

The present work concerns the preparation of new materials based on alginic acid (AA) and diols in a facile and efficient process by improving the adsorption properties of Zn(II) and Ni(II) metal ions on the modified AA. The materials were analysed by zeta potential, thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), in addition to the Fourier Transform InfraRed spectroscopy (FTIR), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) before and after the adsorption behaviour was conducted. The results show that the esterification of AA with diols of different lengths significantly improves its adsorption efficiency of Zn(II) and Ni(II) with Qmax up to 200 mg/g and 185.185 mg/g respectively. Equilibrium and kinetic studies showed that the Langmuir and Freundlich adsorption isotherm models fit the experimental data well, and followed a pseudo-first order kinetic model and the particle diffusion model with correlation coefficients R2 ≈ 1.

Oxalamide-Functionalized Metal Organic Frameworks for CO2 Adsorption.

Metal-organic frameworks (MOFs) have received great attention in recent years as potential adsorbents for CO2 capture due to their unique properties. However, the high cost and their tedious synthesis procedures impede their industrial application. A series of new CO2-philic oxalamide-functionalized MOFs have been solvothermally synthesized: {[Zn3(μ8-OATA)1.5(H2O)2(DMF)]·5/2H2O·5DMF}n (Zn-OATA), {[NH2(CH3)2][Cd(μ4-HOATA)]·H2O·DMF}n (Cd-OATA), and {[Co2(μ7-OATA)(H2O)(DMF)2]·2H2O·3DMF}n (Co-OATA) (H4OATA = N,N'-bis(3,5-dicarboxyphenyl)oxalamide). In Zn-OATA, the [Zn2(CO2)4] SBUs are connected by OATA4- ligands into a 3D framework with 4-connected NbO topology. In Cd-OATA, two anionic frameworks with a dia topology interpenetrated each other to form a porous structure. In Co-OATA, [Co2(CO2)4] units are linked by four OATA4- to form a 3D framework with binodal 4,4-connected 42·84 PtS-type topology. Very interestingly, Cu-OATA can be prepared from Zn-OATA by a facile metal ions exchange procedure without damaging the structure while the CO2 adsorption ability can be largely enhanced when Zn(II) metal ions are exchanged to Cu(II). These new MOFs possess channels decorated by the CO2-philic oxalamide groups and accessible open metal sites, suitable for highly selective CO2 adsorption. Cu-OATA exhibits a significant CO2 adsorption capacity of 25.35 wt % (138.85 cm3/g) at 273 K and 9.84 wt % (50.08 cm3/g) at 298 K under 1 bar with isosteric heat of adsorption (Qst) of about 25 kJ/mol. Cu-OATA presents a very high selectivity of 5.5 for CO2/CH4 and 43.8 for CO2/N2 separation at 0.1 bar, 298 K. Cd-OATA exhibits a CO2 sorption isotherm with hysteresis that can be originated from structural rearrangements. Cd-OATA adsorbs CO2 up to 11.90 wt % (60.58 cm3/g) at 273 K and 2.26 wt % (11.40 cm3/g) at 298 K under 1 bar. Moreover, these new MOFs exhibit high stability in various organic solvents, water, and acidic or basic media. The present work opens a new opportunity in the development of improved and cost-effective MOF adsorbents for highly efficient CO2 capture.

A synergy between the catalytic and structural Zn(II) ions and the enzyme and substrate dynamics underlies the structure-function relationships of matrix metalloproteinase collagenolysis.

Matrix metalloproteinases (MMPs) are Zn(II) dependent endopeptidases involved in the degradation of collagen. Unbalanced collagen breakdown results in numerous pathological conditions, including cardiovascular and neurodegenerative diseases and tumor growth and invasion. Matrix metalloproteinase-1 (MMP-1) is a member of the MMPs family. The enzyme contains catalytic and structural Zn(II) ions. Despite many studies on the enzyme, there is little known about the synergy between the two Zn(II) metal ions and the enzyme and substrate dynamics in MMP-1 structure-function relationships. We performed a computational study of the MMP-1•triple-helical peptide (THP) enzyme•substrate complex to provide this missing insight. Our results revealed Zn(II) ions' importance in modulating the long-range correlated motions in the MMP-1•THP complex. Overall, our results reveal the importance of the catalytic Zn(II) and the role of the structural Zn(II) ion in preserving the integrity of the enzyme active site and the overall enzyme-substrate complex synergy with the dynamics of the enzyme and the substrate. Notably, both Zn(II) sites participate in diverse networks of long-range correlated motions that involve the CAT and HPX domains and the THP substrate, thus exercising a complex role in the stability and functionality of the MMP-1•THP complex. Both the Zn(II) ions have a distinct impact on the structural stability and dynamics of the MMP-1•THP complex. The study shifts the paradigm from the "local role" of the Zn(II) ions with knowledge about their essential role in the long-range dynamics and stability of the overall enzyme•substrate (ES) complex.

Ag-Functionalized Si Nanowire Arrays Aligned Vertically for SERS Detection of Captured Heavy Metal Ions by BSA

A novel surface-enhanced Raman scattering (SERS)-based probe to capture heavy metal ion (Zn2+) by bovine serum albumin (BSA) using Si-nanowire (SiNW) arrays with silver nanoparticles (AgNPs) was developed. A layer with AgNPs was deposited on the SiNW surface by RF magnetron sputtering for enhancement of SERS signals. Using a high-resolution transmission electron microscope (HRTEM), the observation reveals that the AgNP layer with depths of 30–75 nm was successfully deposited on SiNW arrays. The Ag peaks in EDS and XRD spectra of SiNW arrays confirmed the presence of Ag particles on SiNW arrays. The WCA observations showed a high affinity of the Ag–SiNW arrays immobilized with BSA (water contact angle (WCA) = 87.1°) and ZnSO4 (WCA = 8.8°). The results of FTIR analysis illustrate that the conjugate bonds exist between zinc sulfate (ZnSO4) and –OH groups/–NH groups of BSA. The resulting SiNWs/Ag NPs composite interfaces showed large Raman scattering enhancement for the capture of heavy metal ions by BSA with a detection of 0.1 μM. BSA and ZnSO4 conjugations, illustrating specific SERS spectra with high sensitivity, which suggests great promise in developing label-free biosensors.

Insights into interactions of cellulose acetate and metal ions (Zn2+, Cu2+, and Ag+) in aqueous media using DFT study

In this work, we investigate the interaction(adsorption) between cellulose acetate (CA) and three kinds of trace elements (Zn2+, Ag+, and Cu2+) via the DFT. Several parameters have been found after the structure optimization, such as molecular electrostatic potential (MEP), frontier molecular orbitals (FMO), reactivity indexes in addition to the parameters of QTAIM analysis, and the noncovalent interaction (NCI) method with the Multiwfn program. The results of FMOs and MEPs show that the CA has a cite of interaction in the oxygen atom, and the interactions of all complexes occur spontaneously (free energies ΔG<0). Moreover, QTAIM analysis and NCI revealed that the interactions are non-covalent for CA-Ag+and CA-Cu2+ and partially covalent for CA-Zn2+with the apparition of an Hbond for CA-Zn2+and CA-Ag+ and a steric effect for CA-Cu2+. The DFT study has also shown that tetra-coordinated geometry was occurred spontaneously and assigned for Zn2+, Ag+, and Cu2+complexes and di-coordination for Ag+complexes which indicate that the CA polymer can be exploited as a carrier of these ions for pharmaceutical applications.

Revealing Structure–Activity Links in Hydrazine Oxidation: Doping and Nanostructure in Carbide–Carbon Electrocatalysts

The oxidation of hydrazine (N2H4) is an important challenge in electrocatalysis, with applications in direct hydrazine fuel cells and in medical and environmental sensing. Interest in alternative, nitrogen-based fuels for fuel cells was rekindled by recent advances in alkaline membranes, and by the surfacing of challenges in the transportation of hydrogen. Direct hydrazine fuel cells promise high theoretical voltage (1.56 V with O2), clean emissions, and improved fuel transportability.We now report a multi-doped carbide–carbon composite with excellent hydrazine electro-oxidation (HzOR) activity in alkaline pH. While iron carbide containing materials are well known catalysts for several applications (e.g. oxygen reduction and Li-ion batteries), our N-doped, Fe3C-embedded carbons provide the first examples of a carbide-based HzOR catalyst. Multi-doping was thought to enhance reactivity (possibly through cooperation of M=Cu/ Zn, Fe, and edge N atoms), possibly by pore-etching, layers exfoliation or graphitization promotion, thus modulating surface area, mass transfer and conductivity.To prepare the composites, we designed tunable multi-doped precursors: an organometallic structure combining iron with either (1) copper, an element active towards the HzOR, (2) zinc, an electrocatalytically-inert element capable of efficient micropore etching, or (3) iron, to investigate the effect of molybdenum-doping reported earlier. Pyrolysis and washing of the fore mentioned precursors yielded HzOR-active composites of Fe3C nanoparticles and a hierarchically porous, partially graphitic N-doped carbon (NC). Thorough characterization by voltammetry and by a broad range of spectroscopic and microscopic methods revealed that the activity is ordered as: Cu-derived NC > Zn-derived NC > Fe-derived NC. While the catalysts had similar compositions, their nanostructure varied: both Zn- and Cu-doping induced the formation of micropores and small mesopores (5–13 nm diameter). The dopant-induced active site exposure (affecting micropore volume) and improved material flow (linked to mesopore volume) contributed to enhanced HzOR electroactivity. Furthermore, the intimate mixing of the metals in the precursor is hypothesized to homogenize and enhance the doping effect, as the structure enhancing metal ions (Zn2+ or Cu2+) exposed the nearby catalytic Fe3C sites. Acid washing of the pyrolyzed carbon was crucial for producing microporosity in the Cu-based carbon, but had little effect on the Zn-derived one. This revealed the importance of micropores and small mesopores for HzOR electrocatalysis, and the different nanostructuring mechanisms of the two dopants: while Zn(g) boils during pyrolysis and thus etches micropores into the carbon, Cu(s) diffuses and spreads throughout, making exfoliation by acid reaction more efficient. Further work in our group is dedicated to the catalytic activity of pure phase Fe3C, and its modification by other dopants.[Burshtein et al., J. Mater. Chem. A, 7, 41, (23854-23861) 2019, doi: 10.1039/C9TA03357B] Figure 1

Comparative biosorption kinetics study of Ni and Zn metal ions from the aqueous phase in sulfate medium by the wooden biomass of Dalbergia sissoo

Comparative biosorption kinetics study of Ni and Zn metal ions from the aqueous phase in sulfate medium by the wooden biomass of <i>Dalbergia sissoo</i>

MOF–derived hollow porous ZnFe2O4/AgCl/Ag/C nanotubes with magnetic–dielectric synergy as high–performance photocatalysts for hydrogen evolution reaction

The design of unique structures for semiconductor photocatalysts is one of the most effective approach to stimulate their performance toward solar–to–chemical energy conversion. Herein, an interesting scheme has been introduced to produce hollow porous ZnFe2O4/AgCl/Ag/C nanotubes on the PDA@PANI nanofibers by a simple combined PANI capturing–PDA embedding–in situ graphitization process. In a first step, PDA@PANI were first prepared via a coaxial electrospinning process, followed by PANI capturing transition metal ions (Zn2+ and Fe2+) with the assistance of 2,5–dihydroxy–1,4–benzenedicarboxylic acid to convert these metal ions into PDA@PANI@MOF–74–Zn/Fe through thermal treatment. Then, AgCl cubes and Ag NPs were synthesized via in–situ embedding with various active groups of the PDA and its reducibility. At last, after calcination of the PDA@PANI@MOF–74–Zn/Fe/AgCl/Ag, ZnFe2O4/AgCl/Ag/C nanotubes with uniform distribution of graphitic carbon were successfully fabricated. Benefiting from the novel hollow porous structure, the obtained ZnFe2O4/AgCl/Ag/C exhibited outstanding H2 evolution activity (e.g., 7524 µmol h−1 g−1) and high stability without engaging any cocatalyst, which is among the highest reported for ZnFe2O4–based materials with different morphologies and nanostructures.

Synthesis, Spectral, Thermal and Biological Studies of Some Transition and Inner Transition Schiff base Metal Complexes

The new bidentate Schiff base ligand (L) named N1-(diphenylmethylene)naphthalene-1,8-diamine was prepared by the condensation reaction of benzophenone and 1,8-naphthylenediamine. The complexes with Mn(II), Ni(II), Zn(II), La(III), Er(III), and Yb(III) metal ions were prepared and characterized by using elemental analyses (C, H, N and M), FT-IR, 1H NMR, molar conductivity, magnetic moment, UV-Vis, mass and scanning electron microscope (SEM). The temperatures of decomposition of the Schiff base ligand and metal complexes were investigated using thermal analyses. The metal complexes were found to have the formulae [M(L)(H2O)3Cl]Cl.nH2O (M = Mn(II) (n = 4); Ni(II) (n = 2))], [Zn(L)(H2O)2Cl2] and [M(L)(H2O)2Cl2]Cl (M = La(III), Er(III) and Yb(III)) according to the elemental analyses data. The geometrical structure of all complexes was found to be octahedral. The molar conductivity of the complexes in DMF indicated the electrolytic nature of all complexes except Zn(II) complex was non-electrolyte. From the spectroscopic data, the Schiff base ligand acts as NN-bidentate ligand. The biological and anticancer activities of the Schiff base ligand and its complexes were investigated against two bacterial strains, two fungal strains and breast cancer cell line (MCF-7). Docking studies were performed to study the possible interaction between the Schiff base ligand with the active sites of the 3HB5 and 5JPE receptors.

Construction of Isomorphous Coordination Polymers with 2‐(3‐(pyridin‐2‐yl)‐1H‐pyrazol‐1‐yl) acetate Ligand: Structures, Fluorescent Temperature Sensing, and Magnetic Properties

AbstractIn this work, four isomorphous two‐dimensional (2D) complexes, [M(PPA)(HCOO)]n (M=Zn (1), Co (2), Ni (3) and Cd (4)) have been synthesized under solvothermal conditions by mixed 2‐(3‐(pyridin‐2‐yl)‐1H‐pyrazol‐1‐yl) acetate (PPA) with transition metal ion (Zn2+, Co2+, Ni2+ or Cd2+). Single‐crystal and powder X‐ray diffraction show that the four complexes are isomorphous. Due to different electronic configurations for Zn2+, Co2+, Ni2+, and Cd2+, the solid‐state fluorescence properties of 1 and 4, and the temperature dependence of magnetic susceptibility of 2 and 3 were investigated, respectively. The results show that 1 and 4 have obvious blue light emission at the range of 310 to 430 nm with 1.37 % of the quantum yield and 3.80 ns of the lifetime for 1 and 1.67 % and 2.43 ns for 4, respectively. Notably, the intensity‐based fluorescent temperature sensing reveals that both of them can be used as luminescent thermometers. Magnetic investigation of 2 and 3 reveals that strong antiferromagnetic interactions exist within the paramagnetic centers, Co(II) or Ni(II), with −29.09 K of Weiss constant for 2 and −64.02 K for 3, respectively.

Ferrocene-Functionalized Dithiocarbamate Zinc(II) Complexes as Efficient Bifunctional Catalysts for the One-Pot Synthesis of Chromene and Imidazopyrimidine Derivatives via Knoevenagel Condensation Reaction.

Four new mononuclear/coordination polymeric (CP) zinc(II) complexes (1-4) of ferrocenyl/pyridyl-functionalized dithiocarbamate ligands, N-ferrocenylmethyl-N-butyl dithiocarbamate (L1), N-ferrocenylmethyl-N-ethylmorpholine dithiocarbamate (L2), N-ferrocenylmethyl-N-2-(diethylamino)ethylamine dithiocarbamate (L3), and N-4-methoxybenzyl-N-3-methylpyridyl dithiocarbamate (L4), have been synthesized and characterized by elemental analyses, IR, UV-vis, and 1H and 13C{1H} NMR spectroscopic techniques. The solid-state structures of complexes 1, 3, and 4 have been determined by single-crystal X-ray crystallography as well as powder X-ray diffraction. Single-crystal X-ray crystallography revealed a monomeric structure for complex 1 but 1D polymeric structures for complexes 3 and 4. In all complexes, dithiocarbamate ligands are bonded to the Zn(II) metal ion in a S^S chelating mode, and in the CPs, N atoms on the 2-(diethylamino)ethylamine and 3-pyridyl functionalities in the ligands on the neighboring molecules are also bonded to metal centers, leading to the formation of either a discrete tetrahedral molecule in 1 or 1D CP structures in 3 and 4. The Zn(II) metal centers in the polymeric structures exhibited either square-pyramidal or octahedral geometries. The supramolecular structures in these complexes are sustained via C-H···π (ZnCS2, chelate; 3 and 4), C-H···π, and H···H interactions. The catalytic performances of complexes have also been assessed in the Knoevenagel condensation and one-pot multicomponent reactions. Catalysis results showed that the CP 3 acts as a heterogeneous bifunctional catalyst with excellent transformation efficiency at low catalyst loading.

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITY STUDY OF SOME NEW METAL COMPLEXES WITH SCHIFF’S BASES DERIVED FROM [Ο-VANILLIN] WITH [2-AMINO-5-(2-HYDROXY-PHENYL)-1,3,4-THIADIAZOLE

Abstract This study involves the preparation of a new series of dinuclear complexes Cr(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of the Schiff base (H2L) derived from Vanillin with 2amino-5-(2-hydroxy-phenyl)-1,3,4-thiadiazole has been synthesized tetradentate Schiff base ligands were used for complexation upon two metal ions of Cr(III),Co(II), Ni(II), Cu(II) and Zn(II) as dineucler formula M2L2.4H2O and M2L2. These ligands can be characterization IR ,UV-Vis , Mass, 1H-NMR and elemental microanalysis. The Synthesized complexes were characterized by IR, spectroscopy, elemental microanalysis, electronic spectra, magnetic susceptibility conductive ,thermal Analysis (TGA) and atomic absorption on the basis of analytical data, the stoichiometry of metal to ligand in complexes and Schiff bases ligand. The Structures of complexes were proposed from the measurements. The bioactivity of the prepared complexes has been examined with antibacterial activity. Antimicrobial activities of the Schiff base ligand and their metal complexes reveal that the Schiff base transition metal complexes show significant activity against some fungi and bacteria.

Characterization of W-type hexaferrite thin films prepared by chemical solution deposition

Thin films of W-type hexaferrite were grown on SrTiO3(111) single crystals using the chemical solution deposition method and metalorganic precursor solutions prepared using the modified Pechini method. The synthesis of single-phase materials required optimizing the initial stoichiometry and crystallization conditions. The results showed that a concurrent excess of alkaline earth metal and deficiency in divalent metal ion (Zn2+, Co2+) favors the synthesis of pure W hexaferrites. This off-stoichiometry suppressed the formation of an exceedingly stable spinel phase at pyrolysis temperatures. The epitaxial nature of thin films, expressed as the orientation relation (00l)W|| (111)SrTiO3 and [110]W||[112¯]SrTiO3 and hence the pronounced anisotropy of their magnetic properties as well were established by three dimensional x-ray diffraction texture analysis and magnetization measurements, respectively and enabled to identify the temperature interval in which the characteristic spin reorientation transition occurs for a specific degree of cobalt substitution.

Polydopamine-Assisted Rapid One-Step Immobilization of L-Arginine in Capillary as Immobilized Chiral Ligands for Enantioseparation of Dansyl Amino Acids by Chiral Ligand Exchange Capillary Electrochromatography.

Herein, a novel L-arginine (L-Arg)-modified polydopamine (PDA)-coated capillary (PDA/L-Arg@capillary) was firstly fabricated via the basic amino-acid-induced PDA co-deposition strategy and employed to constitute a new chiral ligand exchange capillary electrochromatography (CLE-CEC) method for the high-performance enantioseparation of D,L-amino acids (D,L-AAs) with L-Arg as the immobilized chiral ligand coordinating with the central metal ion Zn(II) as running buffer. Assisted by hydrothermal treatment, the robust immobilization of L-Arg on the capillary inner wall could be facilely achieved within 1 h, prominently improving the synthesis efficiency and simplifying the preparation procedure. The successful preparation of PDA/L-Arg coatings in the capillary was systematically characterized and confirmed using several methods. In comparison with bare and PDA-functionalized capillaries, the enantioseparation capability of the presented CLE-CEC system was significantly enhanced. Eight D,L-AAs were completely separated and three pairs were partially separated under the optimal conditions. The prepared PDA/L-Arg@capillary showed good repeatability and stability. The potential mechanism of the greatly enhanced enantioseparation performance obtained by PDA/L-Arg@capillary was also explored. Moreover, the proposed method was further utilized for studying the enzyme kinetics of L-glutamic dehydrogenase, exhibiting its promising prospects in enzyme assays and other related applications.

Synthesis, Characterization, Antibacterial, Antifungal and Antimalarial Study of Mixed Ligand Metal Complexes Derived from Azo Quinoline with Thiosemicarbazone

Mixed ligand metal complexes of azo quinoline and thiosemicarbazone with Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) metal ions were synthesized. The structure and possible geometry of all the metal(II) complexes were analyzed and supported by IR, mass spectrum, elemental analysis, TG-DTA, electronic spectra (UV), magnetic susceptibility and molar conductance. The synthesized compounds were studied for their antibacterial, antifungal and antimalarial activities. The antimicrobial activity was carried out against bacteria (two Gram-positive bacteria and two Gram-negative bacteria), three fungal strain and one malarial pathogen

Comparative Study on Electrochemical Treatment of Cyanide Wastewater.

The electrochemical treatment of wastewater is widely used for cleaning due to its efficiency. In this paper, two-dimensional (2D) and three-dimensional (3D) electrochemical systems were used to treat cyanide wastewater. The effect of the applied voltage and the material of the main electrode on the removal of various ions and the characteristics of chemical reactions were mainly studied. The results show that the applied voltage was the key effect of the electrochemical treatment process. The removal of ions from the wastewater at 2 V is mainly due to the effect of electro adsorption and enrichment precipitation, while at 4 V, it is mainly due to anodization and cathodic deposition. The treatment effect of the 3D electrode system was significantly better than the 2D system. The 3D electrode system by used granular activated carbon as the particle electrode, with the carbon filled stainless mesh (CM) and coal based electrode (CB) as the main electrode, the treatment effect were better than main electrode of stainless steel mesh (M). The 3D system with CB as the main electrode had an applied voltage of 4 V, a treatment time of 5 h, plate spacing of 10 mm, and the dosage of activated carbon particles was 2 g. The removal rates of CNT, Cu, Zn, CN−, and SCN− were 94.14, 94.53, 98.14, 98.55, and 93.13%, respectively. The main reaction in anode was the electroly oxidation of CN− and SCN−, while the electrolytic deposition of Cu, Zn, and other metal ions in the cathode surface. There were not only adsorption and electric adsorption of various ions, but also an electrolytic deposition reaction of Cu, Zn, and other metal ions on the surface of the activated carbon particle electrode. During the electrochemical reaction, the concentration of hydrogen ions near the anode increases locally, which produces the precipitation of CuSCN, Cu2Fe(CN)6, and Zn2Fe(CN)6, etc. in the solution, which are helpful for the removal of cyanide and heavy metal ions in cyanide wastewater.

CdTe QDs in the presence of L-glutathione capping agents

In this work, we have tuned the surface chemistry of CdTe quantum dots (QDs), by L-glutathione (L-GSH) capping ligand. CdTe QDs are synthesized by aqueous phase route and characterized by using UV–visible and photo luminescence spectrometry. Optical response of capped CdTe QDs is observed to be time and temperature dependent. A strong “Turn-On” fluorescence enhancement of CdTe fluorescence is observed in presence of Zn metals ion. The output of Stern volmer relation and graphical Job’s plot establishes the existence of strong 1:1 complexation between CdTe and Zn metal ion. The proposed optical techniques represent the applicability of functionalized CdTe QD as a successful optical sensor for metal ions detection.

Downregulation of Zn-transporters along with Fe and redox imbalance causes growth and photosynthetic disturbance in Zn-deficient tomato

Zinc (Zn) deficiency hinders growth and development in tomato. This study unveils the responses of how Zn starvation affects physiological and molecular processes in tomato. Zn deficiency negatively affected the biomass, cellular integrity, and chlorophyll synthesis in tomato. Also, Zn deficiency decreased the maximum yield of PSII, photosynthesis performance index and dissipation energy per active reaction center, although the antenna size, trapping energy efficiency and electron transport flux were stable in Zn-starved leaves. Further, Zn shortage caused a substantial reduction in Zn and Fe concentrations in both roots and shoots along with decreased root Fe-reductase activity accompanied by the downregulation of Fe-regulated transporter 1, Zn transporter-like (LOC100037509), and Zn transporter (LOC101255999) genes predicted to be localized in the root plasma membrane. The interactome partners of these Zn transporters are predominantly associated with root-specific metal transporter, ferric-chelate reductase, BHLH transcriptional regulator, and Zn metal ion transporters, suggesting that Zn homeostasis may be tightly linked to the Fe status along with BHLH transcription factor in Zn-deficient tomato. We also noticed elevated O2.− and H2O2 due to Zn deficiency which was consistent with the inefficient antioxidant properties. These findings will be useful in the downstream approach to improve vegetable crops sensitive to Zn-deficiency.