BMC Chemistry最新文献

1,3,4-Oxadiazoles are a vital class of heterocyclic compounds known for their diverse biological activities. In this study, a series of eight novel 1,3,4-oxadiazolyl sulfide derivatives 4a–h were synthesized and characterized using IR, NMR, and elemental analysis. The antioxidant activity of these derivatives was evaluated via DPPH and ABTS assays, revealing promising radical scavenging capabilities Compound 4 h emerged as the most potent antioxidant with SC₅₀ values of 9.88 µM (ABTS) and 12.34 µM (DPPH), outperforming standard antioxidants surpassing standard antioxidants such as ascorbic acid (SC₅₀ = 23.92 µM) and gallic acid (SC₅₀ = 21.24 µM). The impact of electron-donating and electron-withdrawing substituents on activity was demonstrated through a comprehensive structure-activity relationship (SAR) study. Molecular docking against α-glucosidase (PDB: 3W37) validated the potential of these compounds as enzyme inhibitors, with docking scores ranging from − 8.59 to -9.81 kcal/mol and similar modes of binding. Insights into electronic properties were obtained through density functional theory (DFT) calculations, emphasizing that compound with the lowest HOMO–LUMO energy gaps (4b) exhibited higher polarizability and enhanced reactivity, which correlates with their biological antioxidant performance. This integrated study underscores the therapeutic potential of these derivatives as antioxidants and enzyme inhibitors, offering paths for further drug development.

Glass fiber is an inorganic reinforcement material widely used in rubber-based technological products. This study investigates the properties of natural rubber/glass fiber composites, focusing on their potential to enhance mechanical performance while reducing costs. A series of tests were conducted to evaluate the rheological, mechanical, swelling, and morphological characteristics of the investigated natural rubber composites. Quantitative analysis showed that the composition containing 16 phr glass fiber resulted in a 59.5% increase in tensile strength compared to composites filled with traditional fillers such as sodium bentonite, calcium carbonate, silica, and calcined kaolin. The composite also showed a significant boost in mechanical properties, with notable increases in modulus at 100% and 300% strain, strain energy, and a stronger Payne effect, which indicates strong interfacial adhesion, as confirmed by morphological analysis. Morphological analysis of fractured surfaces confirmed excellent adhesion between glass fiber and natural rubber. Notably, the natural rubber/16 phr glass fiber composite exhibited exceptional swelling resistance in toluene, with a quantifiable reduction in swelling compared to other composites. This makes it suitable for automotive interiors. Cytotoxicity tests verified that the material is non-toxic, supporting its use in human-related applications. These results suggest that glass fiber is a better and more sustainable reinforcing filler for enhancing the performance of rubber products in the automotive industry.

Graphical Abstract

Objectives

The study aimed to explore novel aromatic ether coumarins as potential anti-allergic lead compounds.

Methods

The benzene ring of hypervalent iodine compounds was strategically introduced into the coumarin framework to facilitate the efficient synthesis of aromatic ether coumarin derivatives via the one-pot method. Two representative compounds, namely, 4-phenylether coumarin and 7-phenylether coumarin, were successfully designed and synthesized. The compounds were structurally characterized using spectroscopic techniques, including nuclear magnetic resonance (NMR), mass spectrometry (MS), and infrared (IR) spectroscopy. Their inhibitory effects on both IgE- and non-IgE-mediated degranulation of rat basophilic leukemia (RBL-2H3) cells and mouse bone marrow derived mast cells (BMMCs) were subsequently evaluated.

Results

Three representative 7-phenylether coumarins (4, 5, and 6) and 4-phenylether coumarin (7) were synthesized with high efficiency. The compounds exhibited potent anti-allergic effects, indicated by the marked inhibition of degranulation and β-HEX release from RBL-2H3 cells and BMMCs. The inhibitory effects of 7-phenylether 3-methyl ketocoumarin (6) were found to be superior to those of the tested compounds.

Conclusion

Aromatic ether coumarins can be efficiently constructed via the oxidation of hydroxycoumarins with hypervalent iodine compounds. Compound 6 inhibited both IgE-induced and calcium ionophore (A23187)-mediated degranulation of BMMCs, warranting further in-depth investigation into its pharmacogenetic and therapeutic potential.

The extensive use of antibiotics and their persistence in the environment make them emerging pollutants of global concern, posing serious risks to ecosystems and public health. Among them, the broad-spectrum fluoroquinolone antibiotic levofloxacin (LEV) is widely prescribed for bacterial infections and has frequently been detected in freshwater systems and environmental matrices. Its presence is linked to the development of antibiotic resistance and ecological toxicity, underscoring the urgent need for efficient removal strategies. In this study, levofloxacin-imprinted polymers (LEV-MIPs) were developed using a precipitation polymerisation method. A set of nine LEV-MIPs was synthesised using three solvent combinations: ethanol: acetonitrile, ethanol: dimethyl sulfoxide, and ethanol: carbon tetrachloride. Methacrylic acid (MAA) served as the functional monomer (1–3 mmol), ethylene glycol dimethacrylate (EGDMA) as the cross-linker (16 mmol), and azobisisobutyronitrile (AIBN) as the initiator (0.1 mmol). Among them, two formulations (LEV3-MIP and LEV6-MIP) demonstrated superior removal efficiency. Structural and thermal characterisation by FTIR, SEM/EDX, and TGA confirmed successful polymer synthesis, with surface analysis revealing spherical, monodispersed particles of ~ 1.5 μm. Batch adsorption assays showed removal efficiencies of 97.85% (LEV3-MIP) and 99.15% (LEV6-MIP) under optimised conditions (15 ppm initial concentration, 0.3 mg dosage, pH 7, and 90 min and 60 min contact time, respectively). Both polymers exhibited high imprinting factors (3.081 and 3.359) and excellent reusability, with minimal efficiency loss of only 2.7% and 2.09% after ten adsorption–desorption cycles. These results highlight the strong potential of LEV-MIPs as cost-effective, selective, and reusable materials for mitigating antibiotic pollution.

In this study, a range of photocatalysts, including zinc and cerium oxides, were developed using the precipitation technique, while impregnation was used to produce multiwalled CNTs with zinc oxide, multiwalled CNTs with zinc oxide/cerium oxides, and zeolite-based multiwalled CNTs with zinc oxide/cerium oxides. Advanced instruments, such as XRD, UV-Vis, and photoluminescence (PL) devices, were used to analyze the crystal structure, bandgap, and optical properties of each photocatalyst. Methylene blue, an organic contaminant, and sewage from Ethiopia’s Bahir Dar cloth industry were used to assess the photocatalytic efficacy of both assisted and unassisted nanocomposites. Under visible light irradiation, the TZ (zeolite with MWCNTs/ZnO/CeO₂) demonstrated a higher degradation performance of MB dye than the T3 nanocomposite, attaining 93.71% and 83.21%, respectively. This implies that by increasing the adsorption capacity, zeolite greatly improves the composite’s performance. The stability of the TZ in photocatalytic degradation was assessed, showing a 20.8% reduction after four consecutive runs, confirming the nanocomposite’s good stability. Furthermore, the mentioned photocatalyst (TZ) demonstrated greater performance in the degradation of MB with approximately 94.12% compared to the sewage sample efficiency of 76.75%.

Ionic liquids (ILs) have gained significant attention among material scientists for their versatile properties. Amino acid-based ionic liquids (AAILs) have the potential to be tailored for desired physicochemical properties due to their structural adaptability and unique attributes. Twenty-four distinct ILs were synthesized, containing multifunctional cations viz. 1-octyl pyridinium, 1-octyl-3-methylimidazolium, 1,3-dioctylimidazolium, Di-octyldi-butylammonium, Tetraoctylphosphonium, N, N, N', N'-Tetrakis-(2-hydroxyethyl)dioctyldiammonium, 1H-1,2,3-triazole, and 1-octyl-1,8-diazabicyclo(5.4.0)undec-7-enium, each with varied chain lengths. Whereas, bromide, glycinate, and leucinate were incorporated as counter-anionic species. These distinct ILs were characterized by FT-IR, ¹H, and ¹³C-NMR spectroscopies and were systematically evaluated for anti-bacterial efficacy by agar well diffusion method against six potent bacterial strains. Both gram-positive as well as gram-negative types, namely Shigella dysenteria, Shigella boyydii, Staphylococcus aureus, Carbapenem-resistant Enterobacter baumannii, Escherichia coli, and Klebsiella pneumonia were tested. Remarkably strong antibacterial performance was observed across most of the synthesized ILs, particularly notable against gram-negative strains, signifying their potential as antibacterial agents. The good antibacterial performance of ILs was also validated by molecular docking, and a good agreement was found between computational and experimental studies. These findings open new avenues for the development of effective antibacterial agents based on ILs in infection control for individuals with disabilities.

A series of simple and cost-effective benzylidene-amine appended probes (E)-4-((4-(allyloxy) benzylidene)amino)-N-phenyl aniline (L-1), (E)-N-phenyl-4-((2,3,4-trimethoxybenzylidene) amino)aniline (L-2), and (E)-4-((2-nitrobenzylidene)amino)-N-phenyl aniline (L-3) have been developed for the rapid detection of picric acid (PA) and explored for the same. Notably, L-3 showed no changes in its UV spectrum or colour upon interaction with PA. In contrast, when PA was added to L-1 and L-2, there were significant changes in absorption, resulting in distinct colour changes. Mole fraction analysis indicated a 1:1 ratio between the probes and PA. The detection limits for PA were impressively low, measuring 4.37 × 10^− 7 M for L-1 and 4.56 × 10^− 6 M for L-2. This demonstrates the effectiveness of these probes in detecting PA, even at very low concentrations. Importantly, this work marks the first application of benzylidene-amine probes for the detection of PA. The sensing studies were supported by theoretical analyses and calculations, which confirmed the selective detection of PA using matchstick head powder (MSPS) and a test kit based on paper strips. Additionally, smartphone-assisted detection using an RGB tool was successfully demonstrated.

Graphical abstract

The formation of C–C and C–N bonds is an effective means to construct functional complex molecules. Herein, the TsOH-promoted dehydroxylation coupling of diarylmethanols with 1,3-dicarbonyls and sulfonamides to afford a variety of N-alkylated1,3-dicarbonyls and sulfonamides was established with only H₂O as the byproduct. Differential 1,3-dicarbonyls and sulfonamides, including pharmaceutical molecules (sulfinpyrazone, phenylbutazone, mofebutazone, celecoxib, topiramate, valdecoxib) were compatible with this system to couple with alcohols in moderate to excellent yields. This method shows the merits of wide substrate scope and mild conditions.

Graphical abstract

A rapid, accurate, sensitive, and eco-friendly micellar liquid chromatography method has been successfully developed and validated for the simultaneous determination of clindamycin and adapalene in their bulk forms and combined dosage gel formulations. The separation was performed on a BDS HYPERSIL C18 column (150 × 4.6 mm, 5 μm), employing a micellar mobile phase made up of 0.07 M sodium dodecyl sulfate, 0.3% triethylamine, 0.02 M orthophosphoric acid (pH adjusted to 3.0), and 14% isopropanol (v/v). Detection was carried out using UV at 210 nm. The method exhibited linearity in the ranges of 100–500 µg/mL for clindamycin phosphate and 10–50 µg/mL for adapalene, with detection limits of 13.4 µg/mL and 1.4 µg/mL, respectively. The developed method was effectively applied to the analysis of a laboratory-prepared co-formulated gel, yielding high recovery rates. The greenness of the method was further confirmed through assessment with the Green Analytical Procedure Index (GAPI). The method was also validated as a stability-indicating assay for clindamycin phosphate and adapalene under various stress conditions, demonstrating its robustness and applicability for routine quality control.

Luminescent sources based on crystalline materials doped with transition metal or rare-earth cations are known as persistent phosphors, and they can continue to emit light even after the excitation source has disappeared. The present study aims to prepare strontium aluminate with varying weight percentages of Eu²⁺, RE³⁺ (RE = Dy³⁺, Nd³⁺, or B³⁺) oxides by the solid-state preparation followed by firing under active carbon at 1250 °C.The produced phosphors were examined using FTIR spectroscopy, mechano-luminescent measurement, scanning electron microscopy (SEM), and X-ray diffraction (XRD). A bulk density and apparent porosity measurement was also used to assess the impact of the firing temperature at 1250 °C. Photoluminescence characteristics were examined concerning the kind of trivalent oxides doped in strontium aluminate. The results showed that for samples containing 0.15 weight% of Eu₂O₃ and 0.15 weight% of RE₂O₃, SrAl₂O₄ formed with Eu^+ 2, RE³⁺ as a single phase. However, RESr₂AlO₅ was formed together with a minor amount of SrAl₂O₄ when the Eu₂O₃ contents decreased at the expense of the RE₂O₃ contents. Additionally, it was observed that the Eu³⁺ was converted into Eu²⁺ for every sample. Every sample had porous behavior, and the bulk density was increased by the inclusion of RESr₂AlO₅ in addition to SrAl₂O₄. Transitions from the 4f⁶ and 5d¹ configurations of the emission center (Eu²⁺ ions) to the 4f⁷ configuration result in a broad band at peaks of 517 nm in the emission spectra of all the samples. Samples containing RESr₂AlO₅ exhibit high phosphor color characteristics, forming red-orange phosphors encircled by green phosphor rings. Compared to samples containing Nd₂O₃ and B₂O₃, those containing Dy₂O₃ phosphor have the highest decay time values.