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We synthesized a series of 2-aminotropone (N, O)-based borane complexes (2a–2c) in a five-membered scaffold that exhibits strong fluorescence in solution. The photoluminescence lifetimes of these complexes, measured in dichloromethane, range from 3.40 to 3.91 ns. Correspondingly, fluorescence quantum yields of boranes (2a-2c) range from 10% to 15%, indicating the quantum yields and fluorescence decay times have minimal impact of the substituents present on the nitrogen atom. Treatment of these borane complexes with trimethylsilyl trifluoromethanesulfonate (TMS-OTf) results in the formation of mixtures of borenium (three coordinated) and boronium (four coordinated) cations in solution. In contrast, reacting 2-aminotropones with BBr₃ at room temperature selectively afforded boronium cations (4a–4c). All these neutral and cationic complexes were fully characterized using multinuclear NMR spectroscopy and single-crystal x-ray diffraction analysis. Furthermore, Density Functional Theory (DFT) studies were performed to analyze the electronic properties of both neutral and cationic boron species.

Antimicrobial potency is crucial for assessing a drug's effectiveness and for preventing and controlling the growth of microorganisms. In this study, four naphthoquinones—deoxyshikonin, β,β-dimethylacryl shikonin, 2-methylbutyryl shikonin, and acetylshikonin (AS) from Arnebia nobilis and two anthraquinones — chrysophanol and emodin (EM) from Ventilago maderaspatana were isolated using silica gel chromatography. Preliminary screening for minimum inhibitory concentration (MIC) showed that AS showed highest percentage of inhibition against Salmonella enterica serovar Typhi ente (S.Typhi). Solubility was systematically optimized across a pH range of 5–14, with maximum solubility achieved at pH 12 using Na₂HPO₄/NaOH buffer. Antimicrobial screening against S. Typhi revealed AS and EM as most effective, at 25 µg/mL- MIC. Antibiofilm assays portrayed 50% reduction in biofilm formation upon treatment with AS and EM and was validated with fluorescence, crystal violet, and scanning electron microscope (SEM) images. Mechanistic investigations revealed significant intracellular reactive oxygen species (ROS) induction, with increase in membrane permeability and decrease in cell surface hydrophobicity. Further in vivo zebrafish infection models demonstrated a three-fold reduction in bacterial burden, affirming the efficacy and biocompatibility of the AS/EM, and also establishing the value of pH in enhancing solubility of quinones, making them as effective antimicrobial/ anti-biofilm agents.

In this study, electrocatalysts comprising copper nanoparticles and nickel oxide (NiO) have been engineered and investigated for their efficacy in the electrochemical reduction of carbon dioxide (CO₂) to carbon monoxide (CO). The CO production pathway is advantageous due to CO's role as a valuable intermediate in synthesizing various chemicals and fuels, making it a key target for efficient and sustainable CO₂ utilization strategies. Among various concentrations of copper (0.5%, 1%, 2.5%, 5%, and 10%) dispersed over NiO, 1% Cu/NiO system shows the best performance, achieving a Faradaic efficiency of 37%. Electroreduction of CO₂ resulted in the selective production of an industrial fuel, CO. Raman and CO₂-temperature programmed desorption (TPD) demonstrate the differences between NiO and 1% Cu/NiO, which aid in understanding the catalytic systems better. X-ray diffraction (XRD) analysis conducted before and after the reaction demonstrated structural stability of the catalyst. XPS analysis revealed changes in the elemental concentration before and after the electrochemical reaction. Additionally, the electrocatalytic activity of Cu/NiO was compared with its precursors (Cu and NiO), demonstrating that precursor materials exhibited significantly low activity due to the absence of metal-support interactions.

Solid selective catalytic reduction (SCR) is a promising nitrogen oxides abatement technology with advantages over urea-SCR, such as higher ammonia storage density, no low-temperature crystallization, and no exhaust temperature limitation. However, conventional metal chloride adsorbents for solid SCR (SSCR) suffer from two critical issues: ammonia adsorption decay after repeated cycles and poor thermal conductivity, which restrict their practical application. To address these problems, this study aimed to prepare strontium chloride (SrCl₂)/active carbon and SrCl₂/expanded graphite (EG) for SSCR systems and systematically investigate their ammonia adsorption characteristics and key influencing factors. The principal findings are as follows: the optimal mass ratio of SrCl₂ to active carbon/EG was 5:1/6:1, respectively, with the optimal expansion ratio of EG being approximately 148 times, which ensures high initial ammonia adsorption capacity and no adsorption decay during multiple adsorption-desorption cycles. A comparative analysis further showed that the SrCl₂/EG adsorber exhibited higher ammonia bulk density, higher ammonia mass density, and better thermal conductivity than SrCl₂/active carbon. In conclusion, SrCl₂/EG is the optimal composite adsorber for SSCR systems, as its excellent thermal conductivity can enhance the material's heating rate and thereby shorten the ammonia start-up time.

The human epidermal growth factor receptor 2 or HER2 (ErbB2) is a key receptor tyrosine kinase implicated in cancer progression, making it an important therapeutic target. This study evaluated the potential of Laurus nobilis-derived bioactive compounds and biogenically synthesized silver nanoparticles (AgNPs) for targeted HER2-positive cancer therapy. GC–MS analysis of the leaf extract identified 10 major compounds, including phenol, 2-methoxy-3-(2-propenyl)- (49.62%), caryophyllene (7.00%), and germacrene D (1.05%). Molecular docking using AutoDock Vina revealed that desulphosinigrin exhibited the highest HER2-binding affinity (−5.7 kcal/mol), while other compounds showed moderate interactions, suggesting potential inhibitory effects. AgNPs synthesized with the extract were characterized by UV–vis spectrophotometry (SPR peak at 430 nm) and TEM, revealing uniform spherical nanoparticles with an average particle size of 14 nm. FTIR analysis confirmed the presence of functional groups involved in nanoparticle stabilization. Drug-likeness and pharmacokinetic profiling indicated favorable gastrointestinal absorption, hydrophobicity, and hydrogen-bonding capacity, supporting their suitability as therapeutic candidates. Overall, these results demonstrate that Laurus nobilis-derived compounds, particularly when integrated with AgNPs, exhibit promising HER2-targeting potential, providing a basis for further experimental validation in anticancer applications.

In our continued efforts in search for antibiotics active against Helicobacter pylori (HP), the present work demonstrates the antiurease potential of aminoglycosides, tetracyclines, rifaximin, and chloramphenicol. The most active antibiotics during in vitro assays included tobramycin (IC₅₀ 12.64 ± 0.93 µM), rifaximin (IC₅₀ 19.47 ± 0.83 µM), oxytetracycline (IC₅₀ 37.76 ± 0.75 µM), chloramphenicol (IC₅₀ 58.62 ± 0.84 µM) and kanamycin (IC₅₀ 63.75 ± 0.72 µM). Molecular docking studies revealed that rifaximin exhibited the maximum binding affinity (−8.4 kcal/mol), followed by oxytetracycline and tobramycin. The amino acid residues Asp165 and Asp223 in rifaximin, His221 and His332 in oxytetracycline, and Asn168, Gly279, Asp223, and Cyc321 in kanamycin formed conventional hydrogen bonds, and the complexes were further stabilized by hydrophobic interactions. DNA docking studies revealed minor groove binding with maximum binding free energy −10.6 kcal/mol against rifaximin and major groove binding against oxytetracycline with free energy −9.0 kcal/mol. MD simulations for 100 ns yielded RMSD values of 0.302, 0.228, and 0.275 nm for the kanamycin, oxytetracycline, and rifaximin-receptor complexes, respectively. Analyses revealed that the strength and specificity of hydrogen bonds significantly contributed to the overall stability of the complexes. The Rg, SASA, and MMPBSA calculations revealed conformational stability and supported the in vitro findings. These studies suggest exploring new antibiotics as potential antiurease agents.

Covalent-organic frameworks (COFs) offer a confined space to coordinate metal species, holding great promise for heterogeneous catalysis. In this study, a novel COF was synthesized via Schiff base condensation of tris(4-aminophenyl)amine and isophthalaldehyde. An innovative stepwise synthesis method was employed to produce a product with uniform porosity and high crystallinity, which is superior to that achieved by the conventional solvothermal approach. The abundant imine groups in the COF facilitated the coordination of Ni ions, resulting in an active catalyst (Ni@TAPA-IPA) for liquid-phase ethylene oligomerization. Under optimal conditions (MAO as cocatalyst, 0.5 MPa, Al/Ni = 700, 10 min), Ni@TAPA-IPA had a catalytic activity of 7.69 × 10⁴ g/ (mol Ni·h) with a selectivity of 78% for C₄ olefins. Compared to previously reported COF-based systems, the enhanced crystallinity led to a more focused product distribution during ethylene oligomerization. These findings highlight the advantages of COFs in promoting highly selective and efficient catalytic processes, further emphasizing the broad potential of crystalline COFs for applications in ethylene oligomerization.

Hydrogen sensors play a crucial role in monitoring safety in the processes where hydrogen is released or handled in large quantities in fields like chemical and sodium cooled nuclear reactors. An electrochemical sensor in amperometric mode was developed and studied using proton conducting polymer electrolyte membrane of phosphoric acid (PA) doped polybenzimidazole (PBI) PA-PBI. The PA-PBI was characterized using Fourier transform infrared spectroscopy (FTIR) to confirm PA doping. The electrolyte was sandwiched between platinum catalyst coated carbon paper gas diffusion electrodes and hot pressed to make an electrochemical cell. The assembled cell was investigated using an electrochemical impedance spectroscopy over a temperature range of 303–453 K to determine temperature dependent proton conductivity. Activation energy for proton conductivity of the electrolyte was determined to be 24.9 ± 2.7 kJ mol⁻¹. The cell was tested for hydrogen sensing behavior in the hydrogen concentration range of 0.00%–4.00% by keeping the sensor at the optimum temperature of 423 K. The sensor had good sensitivity of about 6.41 mA/% of H₂ in argon with a good repeatability. The sensor was also tested for its effects on relative humidity on hydrogen sensing, interference of the other reducing and oxidizing gases.

A highly efficient, transition-metal–free trifluoromethylation of imidazopyridines has been achieved using Togni reagent I under simple reaction conditions. This operationally simple method, which employs commercially available reagents, displays good functional group compatibility and a broad substrate scope.