BMC Chemistry最新文献

A novel series of hydrazide-hydrazone derivatives incorporating 1,2,4-triazole and 1,2,4-oxadiazole scaffolds was synthesized through multistep condensation and cyclization reactions starting from 4-nitrobenzohydrazide. The structures of the synthesized compounds (MI-1 to MI-9) were confirmed by FTIR, ¹H NMR, and ¹³C NMR spectroscopy, complemented by elemental and mass analyses. Their antioxidant potential was assessed in vitro using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, where several derivatives demonstrated comparable or superior activity to ascorbic acid. To elucidate structure–activity relationships, density functional theory (DFT) calculations were performed to analyze optimized geometries, frontier molecular orbitals (HOMO–LUMO), and molecular electrostatic potential (MEP) surfaces. Furthermore, molecular docking studies against the Keap1–Nrf2 complex revealed favorable binding interactions for select compounds, highlighting their potential as antioxidant modulators through Nrf2 pathway activation. The combined spectroscopic, theoretical, and docking insights provide a comprehensive understanding of the structure–activity relationships of these novel heterocyclic derivatives and support their potential application as antioxidant therapeutic leads.

The limited aqueous solubility of quercetin severely restricts its bioavailability and functional applications. This study demonstrates the effectiveness of a biocompatible choline-tryptophan ionic liquid ([Ch][Trp]) IL in enhancing the solubility and antioxidant performance of quercetin. Incorporation into the IL medium produced a concentration-dependent modulation of 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging activity, with the highest IL concentration (0.18 mM) increasing RSA from 74.76% (quercetin alone) to 78.18%, whereas lower IL concentrations resulted in slightly reduced activity. Physicochemical evaluation of quercetin-[Ch][Trp]-water solutions revealed structure-making behaviour, reflected by a positive Hepler constant and negative S_v values, indicating strengthened water structuring and weak ion-ion interactions conducive to solute stabilization. Spectroscopic analyses supported these findings: UV–Vis absorption exhibited a red shift, fluorescence intensity increased, and FTIR spectra confirmed specific hydrogen-bonding and π-π interactions between quercetin and the IL. Collectively, these results show that [Ch][Trp] creates a favourable micro structured environment that stabilizes quercetin, modulates its radical-scavenging performance, and improves its physicochemical properties. This work highlights the potential of amino-acid-based ILs as green, multifunctional media for improving the performance of poorly water-soluble bioactive compounds.

Graphical abstract

MicroRNAs (miRNAs) are stable and accessible biomarkers for disease diagnosis. Elevated levels of human cytomegalovirus (HCMV)-encoded miRNA-UL22A-5p (miR-UL22A-5p) are associated with virologic recurrence in transplant patients with HCMV infection and can serve as a prognostic marker. Here, we introduce the first electrochemical genosensing platform for the sensitive and accurate detection of miR-UL22A-5p in serum samples. This platform employs a ratiometric strategy to improve probe specificity within complex serum matrices. A new nanocomposite consisting of platinum nanoparticles, effectively oxidised graphene oxide aerogels, and gold nanoparticles (PtNPs/EEGO-AGs/AuNPs) was electrodeposited onto a glassy carbon electrode (GCE). This design boosts sensor performance: PtNPs provide high electrocatalytic activity for signal amplification, EEGO-AGs offer antifouling properties to reduce interference from biological matrices while serving as a substrate for further modification, and AuNPs facilitate stable thiol-mediated attachment of single-stranded DNA probes. Under optimal conditions, the nanobiosensor demonstrated a linear detection range from 10^− 12 to 10^− 5 M, with a detection limit (LOD) of 6.1 × 10^− 13 M and a quantification limit (LOQ) of 2 × 10^− 12 M in human serum. Reproducibility was acceptable, with a standard deviation of 1.8%. To assess its quantitative ability and detection sensitivity, serum samples spiked with miR-UL22A-5p were analysed simultaneously with the biosensor and qRT-PCR, showing that the biosensor has a lower detection limit. This biosensor holds significant potential for clinical use as a sensitive tool for early HCMV detection in transplant patients. However, further validation through prospective clinical trials is necessary to confirm its effectiveness and impact on patient outcomes.

A straightforward, precise, and rapid UV spectrophotometric method has been developed for the simultaneous determination of meclizine (MEC) and pyridoxine (PYR) in binary mixtures. The approach involved two calibration curves: the first was constructed to quantify PYR directly at 290 nm, while the second was used to calculate the concentration ratio (CR) of the mixture at 230 nm. This second curve was generated by plotting the absorbance ratio (AR) against the concentration ratio (CR = [MEC]/[PYR]). Using the experimentally determined concentration ratio (CRₑₓₚ) and the known PYR concentration, the MEC content was calculated as [MEC] = CRₑₓₚ × [PYR]. The method was validated in accordance with ICH Q2 guidelines and demonstrated reliable and consistent performance. When applied to a pharmaceutical formulation, the results expressed as a percentage of the labeled claim were 100.34% ± 0.47 for MEC and 100.04% ± 0.182 for PYR. Furthermore, statistical comparison with a previously published chromatographic method confirmed the equivalence of the two approaches. These results suggest that the developed method is suitable for routine quality control analysis of pharmaceutical preparations containing MEC and PYR. The linearity ranges were 4–20 µg/mL for meclizine and 6–30 µg/mL for pyridoxine and close to 1.00 for both analytes. Excellent precision was demonstrated, with percent Relative Standard Deviations (RSD%) well below 2%. The method also exhibited high accuracy, with analyte recoveries from tablets formulation 99.62 ± 0.34 and 98.92 ± 0.62 for MEC and PYR, respectively.

Porous ceramic materials have generated significant attention and played pioneering roles in a variety of industries. This work aims to prepare porous ceramic composites based on cordierite, mullite, and tetragonal zirconia (t-ZrO₂), which are considered one of the most effective materials in several applications. Nanoparticles were synthesized using sol-gel and co-precipitation methods and then characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), and surface area measurements. The tetragonal form of the prepared nano zirconia was stabilized using ceria. To prepare the cordierite–mullite–t-ZrO₂ macroporous ceramics, nano t-ZrO₂ was added in various ratios from 0 to 30 wt% at the expense of nano mullite, while nano cordierite was added at a 70 wt%. Plant waste materials (bagasse ash and sawdust ash) were recycled and used as pore-forming agents in the fabrication of porous ceramic materials at a constant amount of 10 wt% to increase porosity and reduce environmental pollution problems. The prepared samples were sintered at three different temperatures: 1375, 1400, and 1350 °C. The densification characteristics (bulk density and apparent porosity), cold crushing strength (CCS), phase composition, microstructure, pore size distribution, and contact angle of sintered porous ceramics were studied. The results showed that the bulk density, apparent porosity, and cold crushing strength ranged from 1.42 to 1.95 g/cm³, 46 to 56%, and 3.26 to 31.35 MPa, respectively.

Eugenol, a beneficial nutraceuticals majorly (80–90%) found in clove, has diverse applications due to its antimicrobial and antioxidant properties. Clove is quickly engrossed by diverse organs to metabolize in the liver. To prevent premature absorption and improved activity, water solubility, encapsulation of eugenol is the best solution. Maceration and Soxhlet were performed using ethanol, methanol and water as a solvents. Extracted clove essential oil were successfully encapsulated in gelatin hydrogel. The Soxhlet extraction method had the highest yield (44 ± 0.023) as compared to maceration. Encapsulation efficiency of Clove essential oil in gelatin hydrogel was 84.65 ± 0.12%. Characterization of hydrogel was done using FTIR, SEM and XRD and inclusion of Clove essential oil in hydrogel was established. The radical scavenging activity of Clove essential oil loaded hydrogel enhanced by 57%. (17 ± 0.3) mm and (15 ± 0.2) mm the zone of inhibitions were expressed in terms of gram negative bacteria E. coli. and gram positive bacteria S. aureus. When Clove essential oil incorporated hydrogel was coated on apples via the methods like dipping, brushing, coating was able to enhance the shelf life of fruits as active food packaging material.

Copper ions (Cu²⁺) are environmentally significant due to their toxicity and widespread industrial use. Traditional detection methods are often time-consuming and not amenable to real-time analysis. This study presents the development of a solid-contact ion-selective electrode (SC-ISE) that enables real-time potentiometric monitoring of Cu²⁺ ions during copper nanoparticle (CuNP) synthesis, degradation, and environmental analysis. A novel SC-ISE was fabricated by modifying a screen-printed electrode with polyaniline nanoparticles as the ion-to-electron transducer, and a PVC membrane doped with β-cyclodextrin and Reinecke’s salt for Cu²⁺ selectivity. The sensor’s electrochemical performance was characterized under various conditions and applied for kinetic and thermodynamic studies of CuNP synthesis using L-ascorbic acid. The electrode exhibited a near-Nernstian slope (28.05 mV/decade) across a wide concentration range (10⁻⁸ to 10⁻² mol L⁻¹), a detection limit of 7.5 × 10⁻⁹ mol L⁻¹, fast response time (≤ 10 s), and stable performance within pH 6–9. Real-time monitoring of CuNP formation enabled calculation of activation energy (Ea = 34.06 kJ mol⁻¹), enthalpy (ΔH = 31.21 kJ mol⁻¹), and Gibbs free energy (ΔG > 77.9 kJ mol⁻¹), confirming an endothermic, non-spontaneous process. The electrode also tracked Cu²⁺ release during oxidative nanoparticle degradation and quantified Cu²⁺ in spiked environmental waters with 95.8–98.9% recovery. This study demonstrates, for the first time, the use of a Cu²⁺-selective SC-ISE as a portable kinetic and thermodynamic probe for nanoparticle processes, while also providing a green, low-cost platform for environmental water monitoring.

This investigation developed and evaluated a new type of high-temperature-resistant gel particle system (DPAG), which is specifically designed for conformance control in high-temperature reservoirs. Conventional conformance control systems, including polymer gel systems and foam-based technologies, often suffer from thermal degradation and insufficient plugging stability under high-temperature environments. To address these limitations, DPAG gel particles were synthesized via inverse emulsion polymerization, incorporating thermally stable functional monomers (AMPS and DAC) to create a dual-crosslinking network combining covalent bonds and electrostatic interactions. A comprehensive characterization combining chemical structure assessment, particle size measurement and microscopic morphology examination confirmed the successful synthesis of DPAG gel particles, revealing their uniform size distribution and well-defined morphology. Thermodynamic stability analysis, combined with rheological characterization, revealed that DPAG gel particles exhibit enhanced structural integrity, thermal resistance, and mechanical strength compared to conventional AM gel particles. Swelling kinetic studies revealed that DPAG gel particles exhibit significantly enhanced swelling characteristics, achieved a swelling ratio of 14.6. Experimental results indicated that DPAG microsphere dispersions at concentrations of 0.1% to 0.5% not only maintained excellent injectivity but also achieved remarkable plugging efficiency, reaching up to 98.7%. Particularly under high-temperature conditions, DPAG gel particles displayed outstanding stability, retaining excellent mechanical properties after 30 days with less than 17.4% strength loss. Core flooding experiments demonstrated that DPAG gel particles exhibit both deep migration capability and long-term stability in high-temperature reservoirs, ultimately enhancing oil recovery by 22.4%. These findings strongly indicate the significant potential of DPAG gel particles for well conformance control in high-temperature oilfields.

Multimodal analgesia and rational polypharmacy have emerged as modern pain management strategies, offering synergistic pain relief while mitigating the adverse effects of high-dose monotherapy. A novel antinociceptive fixed-dose combination tablet containing tramadol, ibuprofen, and caffeine exemplifies this approach by integrating a centrally acting weak opioid tramadol, a peripherally acting nonsteroidal anti-inflammatory drugs ibuprofen, and a central nervous system stimulant adjuvant caffeine into a single formulation. In the present work, the first HPLC method for the concurrent quantification of tramadol, ibuprofen and caffeine in bulk powder and tablet dosage forms was developed and validated to support the quality control of this innovative multimodal analgesic fixed-dose combination. The optimal chromatographic separation was achieved using a Zorbax SD-C8 column (150 × 4.6 mm, 5 µm) as the stationary phase. The mobile phase was composed of acetonitrile: 0.01 M phosphate buffer pH 5.0 (35.0: 65.0, v/v), delivered at a flow rate of 1.0 mL/min with UV detection at 220.0 nm. The separation was achieved within 8.0 min, with linearity ranges of 1.0–45.0 μg/mL for tramadol, 1.0–25.0 μg/mL for ibuprofen, and 1.0–30.0 µg/mL for caffeine. The suggested method was validated according to the ICH guidelines and successfully utilized for the quantitative determination of tramadol, ibuprofen and caffeine in bulk powder, laboratory-prepared mixtures and pharmaceutical formulation. The proposed method exhibited outstanding performance for determination of the three cited drugs, characterized by high accuracy (ranging from 100.42% to 100.82%) and excellent precision (< 2% RSD). The sustainability profile of the method was assessed using the Analytical eco-scale, Analytical GREEnness metric, Green analytical procedure index, Blue Applicability Grade Index, White analytical chemistry, and Violet Innovation Grade Index to evaluate the sustainability, applicability, and innovative potential of the proposed method. The method combines analytical rigor, operational simplicity, and sustainable design, setting a new benchmark for analytical support of rational polypharmacy products.