Ligand Ratio Research Articles

1,2,4-triazine derived binuclear lead(ii) complexes: synthesis, spectroscopic and structural investigations and application in organic light-emitting diodes (OLEDs).

Two novel binuclear complexes of Pb(ii) were synthesized by reacting a 3-(2-pyridyl)-5-(4-methoxyphenyl)-1,2,4-triazine (PMPT) ligand with different anionic co-ligands (1: bromide, 2: acetate and isothiocyanate) in a 1 : 1 molar ratio of PMPT ligands to lead(ii) salts. The complexes, [Pb2(μ-PMPT)2Br4] (1) and [Pb2(μ-PMPT)2((μ-CH3COO)2(NCS)2] (2), were characterized using various physicochemical techniques such as CHN analysis, FT-IR spectroscopy, and 1H NMR spectroscopy. Additionally, their structures were determined using single-crystal X-ray diffraction. Based on the obtained structural parameters, complex 1 exhibited a PbN3Br2 environment, while complex 2 displayed a PbN4O3 environment, with holodirected and hemidirected coordination spheres, respectively. Within the crystal network of the complexes, there were interactions involving C-H⋯X (X: O, S, N) as well as π-π stacking. The Pb(ii) complexes were further investigated for their potential use as the emitting layer in organic light-emitting devices (OLEDs). The current-voltage and luminescence-voltage characteristics, as well as the electroluminescence (EL) properties of the complexes, were studied.

A new strategy to construct MOF-on-MOF derivatives for the removal of tetracycline hydrochloride from water by activation of peroxymonosulfate

A MOF-on-MOF composite derivative material named ZIF-67@Ce-MOF-600 was designed and synthesized. The preparation of ZIF-67@Ce-MOF-600 was optimized from the aspects of the ratio of metal and ligand, heat-treatment temperature. It was demonstrated by XRD, FT-IR, SEM-EDS and TEM. The optimum conditions for the activation of PMS by ZIF-67@Ce-MOF-600 for the degradation of tetracycline (TC) were investigated by adjusting the catalyst dosage, TC, pH, peoxymonosulfate (PMS) concentration, and different kinds of water, co-existing anions and pollution. Under optimal conditions (20 mg catalysts and 50 mg PMS added) in 100 mL of tetracyclines (TC) solvent (20 mg TC/L), the removal rate could reach up to 99.2% and after five cycles was 70.5%. The EPR results indicated the presence of free radicals and non-free radical, among which free radicals intended to play a major role in the degradation process. Its possible degradation pathways and attack sites were analyzed by liquid-phase mass spectrometry and DFT analysis.

Design, Synthesis, In vitro and In silico Alpha Glucosidase and Lipoxygenase Inhibition Studies of Copper(II) Oxamide Complexes

AbstractMetal complexes have pivotal applications in catalysis, photochemistry, and biological systems. Due to their unique chemical properties, metal complexes occupy a coveted place in the field of drug design. The present study includes the synthesis of symmetrical oxamides (O1–O11) and their copper complexes (C1–C11) that have potential to inhibit α‐glucosidase and lipoxygenase enzymes. To elucidate the structures of these compounds, spectroscopic investigations including mass spectrometry, 1H‐NMR spectroscopy, UV‐Visible spectroscopy and IR spectroscopy were adapted along with CHN elemental analysis. The spectroscopic investigations suggested that the synthesized complexes to be square planar with metal to ligand ratio 1 : 2. All compounds were scanned for potential inhibitory studies against α‐glucosidase and lipoxygenase enzyme. Their structure activity relationships (SAR) were also established. It was found that all synthesized compounds are strong inhibitors of α‐glucosidase when compared to standard 1‐deoxynojirimycin. It was noteworthy that presence of substituent played a significant role for the enhancing potential inhibitory skills of the compounds. The results obtained were also compared with molecular docking studies. A similar inhibition trend was observed between experimental inhibitory activity and docking energies. The current work presents a special class of Cu(II) coordination complexes from the perspective of their biological as well as structural features.

Low pH Titanium Electrochemistry in the Presence of Sulfuric Acid and its Implications for Redox Flow Battery Applications

Titanium (Ti) is a promising elemental redox active species for redox flow batteries (RFBs) due to its 100x availability in the Earth crust, and 10x lower cost (compared to elemental vanadium). Furthermore, Ti salts are highly soluble in water and concentrations >5 M can be easily obtained. Seeking to harness the higher solubility (and hence energy density) of the Ti electrolyte for flow battery applications, the Ti4+/Ti3+ redox couple was investigated at high concentrations (up to 5 M) relevant to RFB applications. The behavior of Ti ions in H2SO4 supported electrolytes was investigated by varying the ratio of Ti redox active species to counterion. The electrochemical characteristics, transport properties, and redox kinetics of the Ti4+/Ti3+ redox couple were measured and the impact of the Tix+ to solvating ligand ratio was examined. The coordination structures around solvated Tix+ ions were spectroscopically determined and the effect of solvation structure on the Ti3+/Ti4+ redox rate constants were examined and correlated to the calculated solvation energy (hence distinguishing between inner- and outer-sphere processes) and the role of catalysts was addressed. The Ti electrolyte development guidelines presented herein will advance the development of Ti-based RFBs as a promising pathway towards cost effective, grid-scale energy storage.

Ligand-Induced Atomically Segregation-Tunable Alloy Nanoprobes for Enhanced Magnetic Resonance Imaging.

Bimetallic iron-noble metal alloy nanoparticles have emerged as promising contrast agents for magnetic resonance imaging (MRI) due to their biocompatibility and facile control over the element distribution. However, the inherent surface energy discrepancy between iron and noble metal often leads to Fe atom segregation within the nanoparticle, resulting in limited iron-water molecule interactions and, consequently, diminished relaxometric performance. In this study, we present the development of a class of ligand-induced atomically segregation-tunable alloy nanoprobes (STAN) composed of bimetallic iron-gold nanoparticles. By manipulating the oxidation state of Fe on the particle surface through varying molar ratios of oleic acid and oleylamine ligands, we successfully achieve surface Fe enrichment. Under the application of a 9 T MRI system, the optimized STAN formulation, characterized by a surface Fe content of 60.1 at %, exhibits an impressive r1 value of 2.28 mM-1·s-1, along with a low r2/r1 ratio of 6.2. This exceptional performance allows for the clear visualization of hepatic tumors as small as 0.7 mm in diameter in vivo, highlighting the immense potential of STAN as a next-generation contrast agent for highly sensitive MR imaging.

Surface-Functionalized Microgels as Artificial Antigen-Presenting Cells to Regulate Expansion of T Cells.

Artificial antigen-presenting cells (aAPCs) are currently used to manufacture T cells for adoptive therapy in cancer treatment, but a readily tunable and modular system can enable both rapid T cell expansion and control over T cell phenotype. Here, it is shown that microgels with tailored surface biochemical properties can serve as aAPCs to mediate T cell activation and expansion. Surface functionalization of microgels is achieved via layer-by-layer coating using oppositely charged polymers, forming a thin but dense polymer layer on the surface. This facile and versatile approach is compatible with a variety of coating polymers and allows efficient and flexible surface-specific conjugation of defined peptides or proteins. The authors demonstrate that tethering appropriate stimulatory ligands on the microgel surface efficiently activates T cells for polyclonal and antigen-specific expansion. The expansion, phenotype, and functional outcome of primary mouse and human T cells can be regulated by modulating the concentration, ratio, and distribution of stimulatory ligands presented on microgel surfaces as well as the stiffness and viscoelasticity of the microgels.

Optimization of metal–organic framework nanozyme activity via histidine modification for simultaneous pesticide detection

Biosensors provide simple, rapid and sensitive detection of a wide range of analytes. Recently, they have been widely used for the rapid detection of pesticides, which makes up for the shortcomings of traditional detection methods. However, the catalytic activity of some nanozymes is not satisfactory in practical applications, limiting the performance of biosensors. Further development of highly active and stable nanozymes is conducive to improving the sensitivity of the sensors and expanding their application in practical detection. Herein we simulated the amino acid microenvironment of natural enzymes and synthesized His-MIL-101(Fe)-X with different histidine (His) modification amounts (X = 0, 25%, 50%, 75%) by regulating the ratio of histidine and terephthalic acid ligands using a one-step solvothermal method. With increasing histidine doping, the peroxidase-like activity of His-MIL-101(Fe)-X was gradually enhanced, and the sensing performance of the sensor arrays constructed by combining His-MIL-101(Fe)-X with three peroxidase substrates was also gradually improved, with a 25-fold increase in detection limit. The His-MIL-101(Fe)-75% sensor array was not only able to accurately discriminate five pesticides in the range of 2-100 μM, but also to quantitatively identify different concentrations of pesticides. Moreover, the His-MIL-101(Fe)-75% sensor array showed good anti-interference capability and was able to discriminate five pesticides at only 2 μM in soil, lake water, seawater, and apple samples, as well as quantitatively detecting diafenthiuron, which has great potential for practical application.

Synthesis of a novel cost-effective double-ligand Zr-based MOF via an inverted modulator strategy towards enhanced adsorption and photodegradation of tetracycline

Developing visible-light response photocatalysts with high activity and adsorption alongside sustainability is vitally important to environmental restoration. Here, we fabricated a novel metal organic framework (MOF) with cost-effective double-ligands (fumaric acid and 2-aminoterephthalic acid as ligand precursors, denoted as MA-MOF) via a facile solvothermal method. Specifically, crystalline [Zr6O4(OH)4(fumarate)6] (MOF-801) can be only formed with monocarboxylic acids as modulators. Therefore, in the construction of crystalline double-ligand MA-MOF, the absence of monocarboxylic acid modulators successfully prevents the formation of crystalline MOF-801. Instead, the crystalline double-ligand MA-MOF is formed. Properties of MA-MOFs including the surface area, porosity, charge transfer resistance, and energy level position can be adjusted via altering the ratio of ligands. The optimal sample, MA-MOF2 (prepared with a molar ratio of fumaric acid and 2-aminoterephthalic acid being 2:1), shows a total 94.6% removal of tetracycline via adsorption and photodegradation, far exceeding the corresponding single-ligand counterparts. This work proposes an innovative inverted modulator strategy for constructing double-ligand MOFs.

Antibacterial potentials and DNA study of cobalt(II) complexes containing aminophenol Schiff base moiety

The present study was carried out to investigate the effect of substituent groups on the antibacterial activities of 2-aminophenol Schiff bases and their cobalt (II) complexes. Development of new compounds with potential effects against pathogenic organisms has become necessary due to the increase in microbial resistance reported for existing antiseptics and disinfectants. In line with this, new cobalt (II) complexes with Schiff bases derived from 2-aminophenol and p-substituted benzaldehydes were synthesized. The compounds were characterized using elemental analysis, mass spectrometry, atomic absorption spectroscopy, electrospray ionization mass spectrometry, infrared spectroscopy, 1H NMR and electronic absorption spectroscopy. Results indicate that all metal complexes had a 1:2 metal ligand ratio with magnetic moments characteristic of tetrahedral geometry around the metal ion. The Schiff bases and their metal complexes were screened for in-vitro antibacterial activities against 6 human pathogenic bacteria usually found around the hospitals and homes; Escherichia coli (ATCC 8739), Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 19582), Bacillus cereus (10702), Enterococcus faecalis (ATCC 29212) and Kribsella pneumonia (ATCC 10031) with ampicillin used as the reference compound. DNA binding study using calf thymus DNA revealed intercalative mode of activity. The result showed that Schiff bases exhibited moderate inhibitory activity against the tested microorganisms while Schiff base metal complexes exhibited higher antibacterial activity when compared to ampicillin. Our results indicate that these complexes can be employed as active ingredients in development of broad-spectrum antibacterial agents.

Non-Equilibrium Assembly of Atomically-Precise Copper Nanoclusters.

Accurate structure control in dissipative assemblies (DSAs) is vital for precise biological functions. However, accuracy and functionality of artificial DSAs are far from this objective. Herein, a novel approach is introduced by harnessing complex chemical reaction networks rooted in coordination chemistry to create atomically-precise copper nanoclusters (CuNCs), specifically Cu11(µ9-Cl)(µ3-Cl)3L6Cl (L = 4-methyl-piperazine-1-carbodithioate). Cu(I)-ligand ratio change and dynamic Cu(I)-Cu(I) metallophilic/coordination interactions enable the reorganization of CuNCs into metastable CuL2, finally converting into equilibrium [CuL·Y]Cl (Y = MeCN/H2O) via Cu(I) oxidation/reorganization and ligand exchange process. Upon adding ascorbic acid (AA), the system goes further dissipative cycles. It is observed that the encapsulated/bridging halide ions exert subtle influence on the optical properties of CuNCs and topological changes of polymeric networks when integrating CuNCs as crosslink sites. CuNCs duration/switch period could be controlled by varying the ions, AA concentration, O2 pressure and pH. Cu(I)-Cu(I) metallophilic and coordination interactions provide a versatile toolbox for designing delicate life-like materials, paving the way for DSAs with precise structures and functionalities. Furthermore, CuNCs can be employed as modular units within polymers for materials mechanics or functionalization studies.

Controlled synthesis of defective MOF-808 and its application in levulinic acid esterification

Defective MOF-808 (Def. MOF-808) plays a pivotal role in catalysis, offering the potential for optimizing catalytic reactions and enhancing reactivity. Through precise control of MOF-808 synthesis conditions, including time, temperature, zirconium (Zr) source, ligand ratio, defect agent type, and content, we systematically studied their effect on material properties. The results showed that by adjusting these conditions, we synthesized a series of MOF-808 materials with varying defect concentrations, referred to as Def. MOF-808. Shorter synthesis times, lower temperatures, defect agents with stronger coordination capabilities, and increased defect agent concentration or reduced organic ligand concentration effectively enhance Def. MOF-808’s defect concentration. The presence of defect sites facilitates the effective binding of the sulfate group, thereby amplifying the level of sulfation and augmenting its acid catalytic potential. Furthermore, this study unveiled a direct link between defect concentration and the catalytic activity observed in the levulinic acid esterification reaction. The Defect-engineered MOF-808 optimized through response surface design demonstrates exceptional heterogeneous acid catalysis performance, achieving impressive conversion rates of 97.5% and selectivity of 96.2%, coupled with remarkable catalytic stability. This study highlights defect engineering as a successful strategy to improve MOF-808 catalyst performance, offering insights for future enhancements.

Transforming waste into valuables: Preparation and evaluation of dual-ligand hydrophobic charge-induction chromatography using two poor performing ligands

In conventional chromatographic ligand screening, underperforming ligands are often dismissed. However, this practice may inadvertently overlook potential opportunities. This study aims to investigate whether these underperforming ligands can be repurposed as valuable assets. Hydrophobic charge-induction chromatography (HCIC) is chosen as the validation target for its potential as an innovative chromatographic mode. A novel dual-ligand approach is employed, combining two suboptimal ligands (5-Aminobenzimidazole and Tryptamine) to explore enhanced performance and optimization prospects. Various dual-ligand HCIC resins with different ligand densities were synthesized by adjusting the ligand ratio and concentration. The resins were characterized to assess appearance, functional groups, and pore features using SEM, FTIR, and ISEC techniques. Performance assessments were conducted using single-ligand mode resins as controls, evaluating the selectivity against human immunoglobulin G and human serum albumin. Static adsorption experiments were performed to understand pH and salt influence on adsorption. Breakthrough experiments were conducted to assess dynamic adsorption capacity of the novel resin. Finally, chromatographic separation using human serum was performed to evaluate the purity and yield of the resin. Results indicated that the dual-ligand HCIC resin designed for human antibodies demonstrates exceptional selectivity, surpassing not only single ligand states but also outperforming certain high-performing ligand types, particularly under specific salt and pH conditions. Ultimately, a high yield of 83.9 % and purity of 96.7 % were achieved in the separation of hIgG from human serum with the dual-ligand HCIC, significantly superior to the single-ligand resins. In conclusion, through rational design and proper operational conditions, the dual-ligand mode can revitalize underutilized ligands, potentially introducing novel and promising chromatographic modes.

Assessing the antimicrobial and cytotoxic activities of VO(IV), Cr(III), Cu(II)-metformin-schiff-base's complexes enhanced by gold nanoparticles

A new series of VO(IV), Cr(III), and Cu(II) complexes have been synthesized by condensation of metformin with β-diketones (acetylacetone, benzoylacetone, dibenzoylmethane) in the presence of metal salts. The elemental analysis, magnetic susceptibility, conductivity assessments, Infra-Red, UV–visible spectroscopy measurements, SEM, XRD, ESR, GCMS–, DTA, and DTG were used to characterize the novel compounds. The results show that every complex has a metal: ligand ratio of 1:1. The complexes exhibit distorted tetrahedral structural geometry for Cu(II), square pyramidal and octahedral geometry for VO(IV), and octahedral geometry for Cr(III), according to their electronic absorption spectra and magnetic susceptibility studies. Using the computer program Expo2014, crystallographic parameters were estimated for the complexes. The outcomes show that every complex has triclinic crystal structures with the space group P-1, apart from complex [VOL1OSO3], which has a monoclinic structure with the P 1 2 1 space group. In contrast to the complex [VOL1OSO3], which includes monodentate sulfate, conductivity data, XRD, EDX, and GC–MS verified the purity and composition of the compounds being studied. IR data showed that the complexes Na.[VOL2O2SO2] and Na.[VOL3O2SO2] has bidentate chelating sulfate ion. TG, DTG, and DTA have all been used to investigate the complexes' thermal stabilities. Some Schiff-base metformin complexes under investigation had their biological activity evaluated both with and without the addition of AuNPs. Various bacteria and harmful fungi strains have been used to screen the antimicrobial activity. The findings indicate that only copper-loaded Schiff base complexes on AuNPs gave promising results versus Staphylococcus aureus, Escherichia coli, Salmonella, and Candida albicans. On human cell lines of breast cancer (MCF7) and cancer of the human liver (HEPG2), in vitro cytotoxic activity was tested. Results showed that vanadium benzoylacetone doped with gold nanoparticles, with an IC50 value of 7 µg/ml against the HEPG2 cell line and 9.8 against MCF7 has the most effective cytotoxic effect.

Fine-tuning porosity of In-MOFs with ncb topology based on reticular chemistry for one-step purification C2H4 from ternary C2H6/C2H4/C2H2 mixtures

One-step purification of C2H4 from ternary C2H6/C2H4/C2H2 mixtures by single adsorbent is of great industrial significance, but few adsorbents can achieve this purpose. Herein, four isoreticular In-MOFs, In-BDC-AINA, In-ATC-INA, In-Fum-INA, and In-Fum-AINA (H2BDC, H2ATC, H2Fum, HINA, and HAINA are 1,4-benzenedicarboxylic acid, 2-amino-terephthalic acid, fumaric acid, isonicotinic acid and 3-amino-isonicotinic acid, respectively), were designed and synthesized by the guidance of reticular chemistry, using the known In-BDC-INA as the platform, through amino modification and ligand shortening approaches. In-ATC-INA and In-BDC-AINA were aminations of H2BDC and HINA, respectively. In-Fum-INA is replacing H2BDC to shorter H2Fum. In-Fum-AINA is obtained by further amination of In-Fum-INA. Due to the molar ratio of isoniacic and dicarboxylic ligands in this series structure is 2/1, they exhibit different site numbers, site distributions, pore sizes and pore volumes after regulation. These frameworks without open metal sites provided the ability of C2H6/C2H4 inversion adsorption. The amino modification and ligand shortening approaches successfully improved the selectivity of C2H2/C2H4, and the equimolar C2H2/C2H4 selectivities of In-ATC-INA (1.82) and In-Fum-INA (2.81) were higher than that of In-BDC-INA (1.73) calculated by IAST method. The breakthrough results show that In-BDC-INA, In-ATC-INA and In-Fum-INA can achieve one-step separation of the ternary C2 mixtures and the C2H4 yields are 0.08, 0.13 and 0.09 mmol/g, respectively, demonstrating that the two approaches have successfully improved the gas separation performance. In addition, these materials possess exceptional thermal and chemical stability, the low-cost ligand used in In-Fum-INA synthesis further enhances its potential application for industrial gas separation.

Luminescent Supramolecular Metallogels: Drug Loading and Eu(III) as Structural Probe.

Supramolecular metallogels combine the rheological properties of gels with the color, magnetism, and other properties of metal ions. Lanthanide ions such as Eu(III) can be valuable components of metallogels due to their fascinating luminescence. In this work, we combine Eu(III) and iminodiacetic acid (IDA) into luminescent hydrogels. We investigate the tailoring of the rheological properties of these gels by changes in their metal:ligand ratio. Further, we use the highly sensitive Eu(III) luminescence to obtain information about the chemical structure of the materials. In special, we take advantage of computational calculations to employ an indirect method for structural elucidation, in which the simulated luminescent properties of candidate structures are matched to the experimental data. With this strategy, we can propose molecular structures for different EuIDA gels. We also explore the usage of these gels for the loading of bioactive molecules such as OXA, observing that its aldose reductase activity remains present in the gel. We envision that the findings from this work could inspire the development of luminescent hydrogels with tunable rheology for applications such as 3D printing and imaging-guided drug delivery platforms. Finally, Eu(III) emission-based structural elucidation could be a powerful tool in the characterization of advanced materials.

Performance, mechanism, and kinetics of NO removal using ligand-enhanced UV-Fenton driven by O2 from flue gas

Wet free radical advanced oxidation technology such as Fenton reaction is thought to be a very efficient method to remove NO from flue gas, but it requires the consumption of additional oxidants to achieve high removal efficiency. For this purpose, a ligand-enhanced UV-Fenton system without additional oxidants was proposed for NO removal. Three common chelating ligands, EDTA, NTA, and Citrate, were selected to promote UV-Fenton reaction for NO removal. The NO removal performance, mechanism, and kinetics of three different ligand-enhanced photochemical Fenton systems including EDTA/UV/Fe(II), NTA/UV/Fe(II), and Citrate/UV/Fe(II), were studied. Results showed that ligand addition can greatly promote a NO removal in the UV-Fenton system, in the following order of efficiency: EDTA > NTA > Citrate. The mechanism research indicated that these ligands not only enhanced NO oxidation removal by promoting the generation of •OH, but also provided NO complexation removal, which synergized oxidative denitrification and complexation denitrification in the same reaction system, greatly promoting wet NO removal. NO from simulated flue gas was mainly converted into NO3−, NO2−, NH4+, N2, and N2O through synergistic complexation-oxidation. The optimum ratio of ligand to Fe(II) was 1:1 for EDTA and NTA and 3:1 for citrate. NO removal efficiency was increased and then decreased with the increase in pH value or O2 concentration. The low temperature was found to be favorable for NO removal. Furthermore, the kinetics demonstrated that the L/UV/Fe(II) system reaction was a pseudo-first-order process involving nitric oxide. Finally, compared with other Fenton and Fenton-like denitrification systems, EDTA(NTA)-enhanced UV-Fenton system had shown great priority in terms of removal performance, absorbent cost, and waste disposal.

A Novel Lysosome Targeting Chimera for Targeted Protein Degradation via Split-and-Mix Strategy.

Targeted protein degradation is becoming more and more important in the field of drug development. Compared with proteasomal-based degraders, lysosomal-based degraders have a broader target spectrum of targets, which have been demonstrated to have great potential, especially in degrading undruggable proteins. Recently, we developed a programmable and facile screening PROTAC development platform based on peptide self-assembly termed split-and-mix PROTAC (SM-PROTAC). In this study, we applied this technology for the development of lysosome-based degraders, named a split-and-mix chaperone-mediated autophagy-based degrader (SM-CMAD). We successfully demonstrated SM-CMAD as a universal platform by degrading several targets, including ERα, AR, MEK1/2, and BCR-ABL. Different from other lysosomal-based degraders, SM-CMAD was capable of facile screening with programmable ligand ratios. We believe that our work will promote the development of other multifunctional molecules and clinical translation for lysosomal-based degraders.

Aqueous redox batteries including novel copper-ligand complex determined through optimization of ligand

Copper (Cu) is attractive active material for aqueous redox batteries (ARBs) due to its abundance and cheap price, although this is rarely used for this purpose previously. In this study, new water-soluble Cu-ligand complexes are synthesized based on ligand M (N,N-dimethylethylenediamine) and ligand J (N1,N1-dimethyl-N2-(pyridin-2-ylmethyl)ethane-1,2-diamine), and they are used as active material for ARBs. They are then identified by using spectroscopic analyses, such as 1H NMR, 13C NMR, UV–Vis, and ESI-Mass and are stabilized in Cu ion to ligand ratio of 1 to 2 (Cu-M2) and 1 to 1 (Cu-J). More specifically, difference in potential for two Cu ion redox reactions (Cu2+ + e− ↔ Cu+ (RR1) and Cu+ + e− ↔ Cu0 (RR2)) is larger in Cu-J complex (0.33 V) than in Cu-M2 complex (0.1 V), meaning that the two reactions in Cu-J complex are easily controlled to avoid undesirable metallization of Cu ions occurring by RR2. This corroborates that Cu-J complex is more stable than Cu-M2 complex for ARBs in pH 9.25. When performance of ARBs using Cu-J and ferrocyanide is measured, they show outstanding columbic efficiency of 99 %, preserving excellent stability over 200 cycles with low capacity decay rate of 0.001 Ah L−1 cyc−1.

Impact of the arginine silicate inositol complex on bone metabolism in broiler chickens with tibial dyschondroplasia caused by manganese deficiency

ABSTRACT 1. Tibial dyschondroplasia (TD) is a skeletal disorder in broilers that has financial implications, necessitating dietary modifications to reduce the prevalence of this disease. This study explored how arginine silicate inositol complex (ASI) supplementation affected tibial growth plate (TGP) and overall bone health in broilers with manganese (Mn) deficiency-induced TD. 2. A total of 240 broiler chicks were divided into four groups, each consisting of 60 birds (15 replicates of four broilers each) as follows: i) Control, with 60 mg Mn per kg of diet; ii) ASI, with 60 mg Mn and 1 g ASI per kg of diet; iii) TD, with 22 mg Mn per kg of diet, and iv) TD+ASI, with 22 mg Mn and 1 g ASI per kg of diet. 3. It was found that ASI supplementation increased tibial bone length in Mn-deficient TD broilers (p = 0.007). There was no Mn x ASI interaction for other bone morphometry variables (p > 0.05). However, both tibial bone mineral content and density were affected by Mn and ASI (p < 0.05). With ASI supplementation, serum bone-specific alkaline phosphatase and osteocalcin levels were elevated in the TD+ASI group compared to the TD group (p < 0.001). In the TD group, osteoprotegerin (OPG) levels in the TGP decreased compared to the control groups (p < 0.001). 4. In contrast, ASI supplementation in the TD broilers counteracted the decrease in OPG compared to TD broilers without ASI supplementation (p < 0.001). The Mn level and ASI supplementation significantly influenced the OPG/receptor activator of the nuclear factor-κB ligand ratio (p < 0.001). 5. In conclusion, the results demonstrated that inclusion of ASI in broiler diets could enhance bone formation variables by controlling OPG levels in the TGP, potentially serving as an effective method to decrease the occurrence of TD.

Sulfatase-Induced In Situ Formulation of Antineoplastic Supra-PROTACs.

Proteolysis targeting chimera (PROTAC) technology is an innovative strategy for cancer therapy, which, however, suffers from poor targeting delivery and limited capability for protein of interest (POI) degradation. Here, we report a strategy for the in situ formulation of antineoplastic Supra-PROTACs via intracellular sulfatase-responsive assembly of peptides. Coassembling a sulfated peptide with two ligands binding to ubiquitin VHL and Bcl-xL leads to the formation of a pro-Supra-PROTAC, in which the ratio of the two ligands is rationally optimized based on their protein binding affinity. The resulting pro-Supra-PROTAC precisely undergoes enzyme-responsive assembly into nanofibrous Supra-PROTACs in cancer cells overexpressing sulfatase. Mechanistic studies reveal that the pro-Supra-PROTACs selectively cause apparent cytotoxicity to cancer cells through the degradation of Bcl-xL and the activation of caspase-dependent apoptosis, during which the rationally optimized ligand ratio improves the bioactivity for POI degradation and cell death. In vivo studies show that in situ formulation enhanced the tumor accumulation and retention of the pro-Supra-PROTACs, as well as the capability for inhibiting tumor growth with excellent biosafety when coadministrating with chemodrugs. Our findings provide a new approach for enzyme-regulated assembly of peptides in living cells and the development of PROTACs with high targeting delivering and POI degradation efficiency.