BMC Chemistry最新文献

A rapid, sensitive, and selective reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous determination of five dihydropyridines calcium channel blockers, namely: amlodipine (AML), nifedipine (NIF), lercanidipine (LER), nimodipine (NIM) and nitrendipine (NIT) using Quality by Design approaches (QbD). The chromatographic separation was achieved on Luna C8 (100 × 4.6 mm 3 μm) column using an isocratic mobile phase consisting of acetonitrile—methanol − 0.7% triethylamine pH 3.06 (30-35-35) adjusted with ortho phosphoric acid at a flow rate of 1 mL/min with UV detection at 237 nm. The optimized method demonstrated good chromatographic resolution with average retention times of 2.93, 3.98, 4.98, 6.32 and 7.75 min for AML, NIF, LER, NIT and NIM, respectively. The method was validated according to ICH guidelines, showing linearity in the concentration range of 10–50 µg/mL with correlation coefficients (r²) ≥ 0.9989 for all analytes. The method demonstrated high trueness (99.11–100.09%) and precision (RSD < 1.1%). The validated method was successfully applied for the determination of these drugs in their pharmaceutical formulations, with recovery values ranging from 99.57 to 100.07% and without significant interference from excipients. Greenness and practicality evaluations detected using AGREE, MoGAPI, complex MoGAPI, AGSA, CaFRI, BAGI and CACI tools which were, indicating the method’s environmental friendliness and excellent practical applicability for routine pharmaceutical quality control analysis.

This work focused on the synthesis of nickel oxide under varying hydrothermal conditions as a non-precious and efficient catalyst for NaBH₄ hydrolysis to generate hydrogen. The structural, morphological, and textural features of the calcined samples were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and N₂-physisorption techniques. XPS analysis confirmed the presence of Ni²⁺ and Ni³⁺ species, with varying Ni³⁺/Ni²⁺ ratios across the samples. The NH-200 samples showed the highest hydrogen generation rate, approximately 1290 at 323 K, attributed to the enhanced redox behavior of Ni³⁺ ions. N₂-adsorption results revealed mesoporous structures with distinct surface areas and pore characteristics. The catalytic performance was evaluated at 35–50 °C, showing enhanced activity with increasing temperature and NaBH₄ concentration (up to 4.5 wt.%). Activation energies were found to be below 59 kJ mol⁻¹. The catalyst maintained good stability over five consecutive cycles with only a slight performance decline. These findings confirm that NiO is a cost-effective, active, and reusable catalyst for hydrogen generation via NaBH₄ hydrolysis.

This work demonstrates simple and reliable spectrophotometric methods for the simultaneous determination of paracetamol (PAR) and meloxicam (MEL) in mixture I as well as PAR and domperidone (DOM) in mixture II in bulk form and laboratory-made tablets. Successful determination of mixture I was accomplished using direct zero-order spectrophotometry at 361 nm for MEL and first-order derivative (¹D) spectrophotometry by measuring the peak at 342 nm and the trough at 262 nm for MEL and PAR respectively. On the other hand, a ratio difference method was suggested for the analysis of mixture II. The difference between the ratio spectra amplitudes at 256 and 288 nm were recorded for PAR determination, and 216 and 288 nm for DOM quantitation using 50 µg/mL DOM and PAR respectively as divisors. The efficacy of the proposed procedures was assessed using ICH criteria for linearity, ranges, precision, accuracy, detection, and quantitation limits. With regard to mixture I, the calibration curves showed linearity in the ranges of 3–30 µg/mL for MEL (zero-order method) and 2.5–30 and 3–15 µg/mL for MEL and PAR, respectively (first-order method), with correlation values of at least 0.9991.Whereas for mixture II, with correlation coefficients of 0.9999, the calibration curves for PAR and DOM were linear in the ranges of 3–70 and 2.5–15 µg/mL, respectively.The established procedures were used to analyze the combinations in the lab-prepared pills, and assay results were compared with reported methods. Greenness of the devised spectrophotometric procedures was assessed using the Analytical Eco-Scale and the Analytical Greenness metric (AGREE).

Molnupiravir (MOL) is a recently developed oral antiviral drug. MOL has been clinically evaluated for its efficacy against COVID-19. In this work, we utilize UV-absorption spectroscopy, fluorescence spectroscopy, synchronous fluorescence, molecular docking and molecular dynamic (MD) simulation to study the interaction between MOL and bovine serum albumin (BSA). The fluorescence spectroscopic analysis indicated that MOL effectively quenched the intrinsic fluorescence of BSA. To elucidate the fluorescence quenching mechanism, the interaction of MOL with BSA was examined at five distinct temperatures (285 K, 290 K, 295 K, 303 K and 308 K). The quenching constants diminished as the temperature increased, suggesting a static quenching mechanism, as evidenced by the Stern–Volmer plots of F0/F against the molar concentrations of MOL. This was further confirmed by UV absorption spectroscopy. Thermodynamic analysis revealed a 1:1 stoichiometry for MOL binding to BSA, with a negative Gibbs free energy change (ΔG), confirming the spontaneous nature of binding. Competitive binding experiments using site-specific markers as well as molecular docking studies showed that MOL binds to site II. Synchronous fluorescence spectroscopy indicated that MOL was binding around tyrosine (Tyr) residues of the protein. These findings were further confirmed by the molecular docking and MD simulation studies. This research could provide valuable insights into the pharmacokinetics and pharmacodynamics of MOL, which could contribute to the development of more effective antiviral drugs.

Graphical Abstract

A novel bi-ligand nickel-based metal–organic framework (Ni-BTC-PYDC MOF) was synthesized using benzene tricarboxylic acid (BTC) and pyridine-2,3-dicarboxylic acid (PYDC) as ligands. This MOF showed improved surface area, structural stability, and electron transfer compared to mono-ligand Ni-MOFs. Characterization by SEM, EDX, EDS mapping, XRD, and FT-IR confirmed its enhanced morphology and nickel content. The catalyst rapidly reduced methyl orange (MO) dye in water, achieving rapid and significant decolorization within 90 s using sodium borohydride (NaBH₄) under mild conditions. It maintained high activity over ten reuse cycles with minimal loss, performing best at pH 5 due to efficient hydride generation and proton-assisted electron transfer. These findings demonstrate that the bi-ligand Ni-MOF is a promising, stable, and reusable catalyst for removing toxic azo dyes from wastewater.

The present study investigated the production of biscuit from African yam beans/sweet potato composite flour fortified with African star apple. Biscuits, produced from African yam beans (AYB), sweet potato (STP) and African star apple (ASA) flour blends in the ratios (AYB: STP: ASA): 50:45:5; 45:45:10; and 40:40:20, were subjected to analysis of proximate composition, and physical and sensory properties; while the blends were analysed for functional properties. Biscuits made from AYB: STP (50:50) blend served as control. Moisture, ash, fat, fiber, protein and carbohydrate contents ranged from 5.90 to 7.30%; 2.17–2.26%; 8.30–9.10%; 6.75–7.47%; 12.50-12.95%, and 61.85–63.25% respectively. Fiber and fat contents increased with increasing levels of ASA. Spread ratio ranged from 19.39 to 19.86; thickness from 2.52 to 2.56 mm; diameter, 50.21 to 50.97 mm; and weight, 13.26 to 15.77 g. Thickness and diameter of biscuits also increased as the percentage of ASA increased. Based on sensory scores, biscuits made from AYB: STP: ASA blend in the ratio of 50:45:5 were preferred to the control and samples made from other blend ratios. The above findings suggest that, AYB: STP: ASA blend containing less that 10% ASA can be considered the ideal ratio for the production of nutritious and organoleptically acceptable biscuits.

This study presents the development and validation of a novel reverse-phase ultra-high-performance liquid chromatography (UHPLC) method for quantifying tiopronin residues on manufacturing equipment surfaces as part of cleaning validation. Tiopronin, a synthetic thiol compound with therapeutic applications, requires stringent manufacturing controls to ensure product safety and efficacy. Existing analytical techniques mainly focus on quantifying tiopronin in pharmaceutical formulations or biological matrices. However, no methods specifically address cleaning validation for tiopronin production equipment. Using an Analytical Quality by Design approach, this UHPLC method was optimized and validated by ICH Q2 (R2) guidelines. The technique employs a Waters ACQUITY UPLC H-Class PLUS C-18 column (100 mm × 2.1 mm, 1.7 µm) with a mobile phase of 88:12 (v/v) 0.1% v/v orthophosphoric acid (pH 2.1) and acetonitrile, achieving a tiopronin retention time of 1.3 min. The method demonstrated specificity, precision, accuracy, and linearity over a concentration range of 0.302 to 3.027 µg/mL. The limit of detection and quantification were 0.100 µg/mL and 0.301 µg/mL, respectively. The greenness of the method was assessed using AGREE, GAPI, and RGB 12 tools. The scores obtained were 0.67 for AGREE, 85.0 for BAGI, and 82.1 for RGB 12 suggesting proposed method is environment friendly. This novel method provides an efficient, eco-friendly solution for routine cleaning validation, addressing a significant gap in existing analytical techniques for tiopronin manufacturing.

Graphite carbon nitride (g-C₃N₄) has emerged as a promising photocatalyst for visible-light-driven applications due to its suitable band structure. However, the rapid recombination of photogenerated electron-hole pairs in bulk g-C₃N₄ significantly hinders its photocatalytic efficiency. In this study, we report the fabrication of a ternary g-C₃N₄/MoS₂/rGO (CMG) nanocomposite via in situ photoreduction-induced exfoliation. The introduction of MoS₂ and rGO not only facilitates the exfoliation of g-C₃N₄ into ultrathin nanosheet, thereby exposing more active sites, but also enables the formation of tightly coupled heterojunctions that promote charge separation and transfer. Photoluminescence (PL) analyses confirm the suppressed recombination of charge carriers, indicative of enhanced charge dynamics within the heterojunction between MoS₂, rGO and g-C₃N₄. Among the synthesized materials, the optimized CMG-175 composite exhibits remarkable photocatalytic activity, achieving a 95.7% degradation rate of Rhodamine B (RhB) within 30 min under visible light irradiation, which is 23.6-fold enhancement compared to pristine g-C₃N₄. Mechanistic studies reveal that photogenerated holes and superoxide radicals are the predominant reactive species driving the degradation process. This work highlights a rational design strategy for constructing high-performance g-C₃N₄-based heterojunction photocatalysts and provides valuable insight into the synergistic interactions among MoS₂, rGO, and g-C₃N₄ for efficient organic pollutant removal.

Determination of pharmaceuticals in biological matrices is crucial for pharmaceutical development, toxicological studies, and therapeutic drug monitoring. Accurate quantification of drugs in plasma requires reliable analytical techniques; however, the complexity of biological fluids hinders direct analysis without an effective sample preparation step. In this study, Fe₃O₄ was synthesized using mussel-inspired magnetic molecularly imprinted polymer nanoparticles (MIP NPs) through a single-step auto-polymerization process with levofloxacin as the template and methyldopa as the monomer. The integration of Fe₃O₄ core synthesis, self-polymerization, and molecular imprinting in a single step provides a unique and streamlined methodology, reducing fabrication complexity and time. The prepared Fe₃O₄@MIP NPs were successfully applied to extract levofloxacin from spiked human plasma. UV–spectroscopy studies confirmed selective recognition, binding efficiency, and optimization of recovery conditions, achieving approximately 93.5% recovery. The Fe₃O₄@MIP NPs demonstrated significant imprinting capability and high adsorption capacity. This approach offers a novel and cost-effective platform for rapid, selective drug extraction from complex biological matrices, with direct clinical relevance for therapeutic drug monitoring of levofloxacin in multidrug-resistant tuberculosis, particularly suited for resource-limited settings.

Ivermectin, a poorly water-soluble drug, faces challenges like slow dissolution and variable absorption, affecting its efficacy. While some solubility data exist for ivermectin in mono-solvents and a few binary mixtures, research on its solubility in broader solvent combinations remains limited. This investigation aimed to elucidate the solubility and thermodynamic profiles of ivermectin in binary solvent systems comprising (polyethylene glycol 200 + water) and (polyethylene glycol 400 + water) within a temperature range of 293.2 to 313.2 K. The experimental solubility data were analyzed utilizing various linear and nonlinear models, including van’t Hoff, Jouyban-Acree, Jouyban-Acree-van’t Hoff, and mixture response surface methods. The efficacy of these models was assessed by evaluating their mean relative deviations from the experimental values. Furthermore, apparent thermodynamic parameters, including Gibbs energy, enthalpy, and entropy were calculated using the van’t Hoff and Gibbs equations.