Frontiers in Chemistry最新文献

Introduction: Morocco is home to a remarkable diversity of flora, including several species from the Artemisia genus. This study aims to thoroughly examine the chemical composition of essential oils derived from Artemisia species and assess their antibacterial and antioxidant properties through in vitro experiments and in silico simulations.

Methods: Samples of Artemisia herba-alba Asso. were collected from Boulemane and Ifrane in Morocco, while Artemisia huguetii Caball. was sampled from Tata, representing regions of the Central Middle Atlas and Western Anti-Atlas. Essential oils were extracted using hydrodistillation, and their chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). Antibacterial and antifungal activities were evaluated, and antioxidant properties were assessed using the DPPH assay. In silico predictions of antibacterial and antioxidant activities were performed using computational models.

Results: The extraction yields varied depending on the geographical origin, ranging from 1.54% to 2.78%. GC-MS analysis revealed significant differences in the chemical composition of the oils from different Artemisia species and regions, with a notable prevalence of oxygenated monoterpenes. Specifically, the oil from Boulemane was rich in thujone, the oil from Ifrane was predominantly composed of camphor, and the oil from Tata contained both camphor and thujone. The oils exhibited stronger antifungal than antibacterial properties, with Enterobacter cloacae strains showing high sensitivity, with minimum inhibitory concentrations (MIC) of approximately 12.5 mg/mL. The Boulemane oil of A. herba-alba displayed the highest antioxidant activity, effectively inhibiting DPPH at a concentration of 13.501 μg/mL.

Discussion: The in silico simulations predicted that the primary compounds in these essential oils, such as davanone, eucalyptol, camphor, and thujone, would exhibit potent antibacterial and antioxidant properties. These compounds were found to have favorable ADMET characteristics, including good blood-brain barrier permeability, gastrointestinal absorption, and skin penetration. Molecular docking studies revealed strong interactions between these compounds and key target proteins, such as NADPH-dependent catalase and dihydrofolate reductase. The stability of the protein-ligand complexes was confirmed by molecular dynamics, with davanone showing a significant impact. Overall, this study provides a comprehensive understanding of the biological potential of Artemisia essential oils, highlighting davanone as a promising molecule for medicinal or pharmaceutical applications.

Detecting dissolved gases in transformer oil is crucial for assessing the operational status of transformers. The gas composition in transformer oil can reflect the health status of the equipment and help identify potential failure risks in a timely manner. Based on density functional theory (DFT), Pd and Rh atoms were doped into the h-BN monolayer, and the most stable adsorption structures for each were first explored. Then, the sensing performance of the Pd-doped and Rh-doped h-BN monolayers for H₂, CH₄, and C₂H₄ gases was analyzed. The results indicate that Pd-BN and Rh-BN exhibit enhanced sensitivity to H₂ and C₂H₄ gases compared to pristine h-BN. However, they show poor adsorption characteristics for CH₄. Both Pd-BN and Rh-BN demonstrate strong chemisorption for H₂ and C₂H₄. In contrast, CH₄ adsorption is predominantly physisorbed. The desorption time of H₂ from Pd-BN at 398 K is 164 s, reflecting its excellent desorption performance. Additionally, Pd-BN and Rh-BN monolayers exhibit exceptional C₂H₄ capture capabilities, with adsorption energies of -1.697 eV and -2.188 eV, respectively, indicating their potential as C₂H₄ gas adsorbents. These findings provide theoretical insights for selecting materials for dissolved gas detection in oil and lay the groundwork for the development of Pd-BN and Rh-BN-based gas sensors.

Lattice-based mean-field models of ionic liquids neglect charge discreteness and ion correlations. To address these limitations, we propose separating the short-range and long-range parts of the electrostatic interaction by truncating the Coulomb potential below a fixed distance that is equal to or slightly larger than that between neighboring ions. Interactions and correlations between adjacent ions can then be modeled explicitly, whereas longer-ranged electrostatic interactions are captured on the mean-field level. We implement this approximation into the framework of modeling a compact, solvent-free ionic liquid by, first, considering terms up to the fourth order of the operator that represents the truncated Coulomb potential and, second, by accounting for electrostatic correlations between pairs of neighboring ions on the level of the quasi-chemical approach. A set of boundary conditions for the resulting self-consistent fourth-order differential equation follows from functional minimization of the free energy. The differential capacitance of an ionic liquid in contact with a planar electrode is calculated analytically up to quadratic order in the electrode's surface charge density by solving the linearized model and applying a perturbation approach valid beyond the linear regime. We demonstrate that charge discreteness enhances the differential capacitance, whereas electrostatic correlations between ion-ion pairs drive the transition from a bell-shaped to a camel-shaped profile of differential capacitance. Our approach offers a systematic way to further improve the treatment of charge discreteness, account for short-range electrostatic and non-electrostatic interactions, and include higher-order ion-ion correlations.

Background: The basidiomycetes Pleurotus eryngii var. ferulae Lanzi and P. eryngii var. elaeoselini Venturella et al. belong to the P. eryngii species complex, acting as facultative biotrophs in association with members of Apiaceae family, i.e., Ferula communis L. and Elaeoselinum asclepium L., respectively. The consumption of these fungi has rapidly increased in recent decades, not only thanks to their nutritional properties and pleasant flavor, but also for their bioactive and medicinal properties.

Methods: A quantitative study of their hydroalcoholic extracts was carried out by liquid chromatography-mass spectrometry. The potential antimicrobial activity of the extracts was also tested against some phytopathogenic bacteria [Clavibacter michiganensis and Bacillus megaterium (Gram-positive), Pseudomonas viridiflava, Xanthomonas campestris, and Escherichia coli (Gram-negative)] and fungi (Aspergillus fumigatus, Penicillium italicum, Monilinia laxa, Botrytis cinerea, Cadophora sp., and Sclerotinia sclerotiorum).

Results: The chemical analysis allowed the identification of secondary metabolites belonging to different classes, as flavonoids, organic acids, amino acids, carbohydrates, vitamins, nucleic acids, fatty acids, and triterpenoids. Both extracts demonstrated antimicrobial activity against of the most tested microorganisms.

Conclusion: The results can broaden the knowledge on the possible use of these fungal species in the agricultural sector.

To fully harness the potential of smart textiles, it is cruical to develop energy harvesters which can function both as fabric and energy generator. In this work, we present a high performance low-cost piezoelectric nano-fabric using even-number Nylon (i.e., Nylon-6). Nylon-6 was chosen for optimal mechanical properties such as mechanical strength and stiffness. To maximize the voltage output, Nylon six nanofibers with varying diameter and crystallinity were synthesized by adjusting the polymer precursor and solvent, along with electrospinning parameters, followed by post thermal treatment. The average diameter of electrospun nanofibers was finely tuned (down to 36 nm) by adjusting solution polymer precursor content and electrospinning parameters. The content of desired piezoelectric-active γ crystal phase enhanced upto 76.4% by controlling solvent types and post thermal annealing. The highest peak to peak voltage (V₃₃) of 1.96 V were achieved from γ-phase dominant (>60%) Nylon-6 nanofiber fabric which has an average nanofiber diameter of 36 nm with high fiber fraction (i.e., > 98%). Unlike its thin film counterpart, piezoelectric electrospun nanofiber fabric demonstrated durability against wear and washing. This work paves a new way to utilize Nylon-6 nanofibers in next-generation electronic textiles.

Halogens favorably contributes to the drug potency and metabolic stability via electrostatic interactions. Herein, the halogen effects on the reactivity of the halogenated 2,2,2-trifluoroacetophenones as serine-targeting covalent warheads were investigated. Our results showed that introducing halogen atoms, especially Cl or Br, into the phenyl scaffold would influence the electron density around the ring, which led to different time-dependent inhibition response to the target serine hydrolase (hCES1A). Co-crystallography analysis not only verified that halogenated molecules preferred to form covalent adducts, but also provided the conformational information for the design of covalent inhibitors targeting to hCES1A protein for the treatment of drug-induced acute enteritis.

The Chinese medicinal plant Thesium chinense Turcz. is the only plant used in the manufacture of Bairui Granules. However, to date, there has been very little research into the cytotoxic activity of active substances derived from Bairui Granules. Using chemical separation and spectroscopic methods, phenolic compounds 1-5 were identified as methyl-p-hydroxycinnamate, vanillin, kaempferol, isorhamnetin-3-O-glucoside, and astragalin, respectively. UPLC-MS/MS analyses revealed that compounds 1-5 were present at concentrations of 0.006 ± 0.002, 1.63 ± 0.87, 3.65 ± 0.83, 26.97 ± 11.41, and 27.67 ± 2.91 μg/g, respectively in Bairui Granules. Compounds 1, 2, and 4 were detected here for the first time in Bairui Granules. Using co-culture experiments, isorhamnetin-3-O-glucoside (4) was found to be beneficial to the proliferation Chinese hamster ovary (CHO) cells (6.46% ± 0.86% to 38.45% ± 9.04%), natural killer cells from human umbilical cord blood (UCB NK cells) (25.68% ± 0.02% to 70.81% ± 0.26%), and mesenchymal stem cells from human umbilical cord blood (UCB MSC cells) (1.66% ± 0.05% to 27.64% ± 0.51%) when the concentration was similar to that found in Bairui granules. Moreover, vanillin (2) was conducive to UCB NK cells proliferation (28.21% ± 0.44%) at a concentration of 64 μg/mL, while maintaining cell viability. UCB NK cell proliferation was promoted at rates of 41.03% ± 0.48% to 67.22% ± 0.68% when astragalin (5) was present at low concentrations (8 and 16 μg/mL). Methyl-p-hydroxycinnamate (1) and vanillin (2) at different concentrations both had an inhibitory effect on the proliferation of natural killer cells from human peripheral blood (PB NK cells), but the inhibitory concentration ranges of these compounds were not equivalent to the concentration ranges of the compounds in Bairui Granules. These results provide a foundation for the safe use of T. chinense preparations.

Studies on cerium oxo clusters (CeOCs) are not only significant for understanding the redox and hydrolysis behaviors of Ce(III/IV) ions but also crucial for the rational synthesis of novel clusters and nanoceria with specific Ce(III)/Ce(IV) ratios. Here, two sets of reactions were conducted using cerium nitrate and H₂O₂-oxidized cerium nitrate, resulting in the formation of two distinct mixed-valent CeOCs [Ce^III ₄Ce^IV ₁₀O₁₄(OH)₂(PhCO₂)₂₂(DMF)₆] (Ce₁₄) and [Ce^III ₂Ce^IV ₂₂O₂₈(OH)₈(PhCO₂)₃₀(DMF)₄] (Ce_24C). These two clusters exhibit different structures and Ce(III)/Ce(IV) ratios, demonstrating the critical role of cerium oxidation states and the occurrence of redox reactions in cluster formation. Ce₁₄ is the first tetradecanuclear CeOC with a novel structure, whereas Ce_24C differed in its Ce(III)/Ce(IV) ratio, protonation levels of O atoms, and ligands from previously reported 24-nuclear CeOCs. Furthermore, various techniques were employed to investigate the formation process of these two clusters. X-ray photoelectron spectra (XPS) revealed that the white precipitates formed during the preparation of Ce₁₄ contain Ce(III) ions, while the reddish-brown precipitates formed during the preparation of Ce_24C contain a mixture of Ce(III) and Ce(IV) ions. These two precipitations were individually dissolved in N,N-Dimethylformamide (DMF). The evolution of solution color and ultraviolet-visible (UV-Vis) spectra over time revealed the gradual oxidation of partial Ce(III) ions by oxygen in the solution of the white precipitation. As Ce(IV) ions increased in this solution, time-resolved small angle X-ray scattering (SAXS) data demonstrated the self-assembly of the Ce₁₄ clusters after 4 days. In contrast, SAXS data and UV-Vis spectra revealed the rapid assembly of Ce_24C clusters within 2 h due to the initial coexistence of Ce(IV) and Ce(III) ions in the DMF solution of the reddish-brown precipitation. The continued reduction of partial Ce(IV) ions in this solution does not affect Ce_24C clusters' formation and stability. Our studies expand the family of CeOCs and enhance our understanding of the effects of cerium's oxidation states on cluster formation.

Objectives: Immune checkpoint inhibitors (ICIs) have demonstrated potential in inhibiting the growth of malignant pleural mesothelioma (MPM), and their efficacy is associated with the expression of programmed death-ligand 1(PD-L1). This study evaluated a PD-L1-targeted nanoprobe for detecting PD-L1 expression in a nude mouse model of malignant pleural mesothelioma (MPM).

Methods: A PD-L1-binding peptide (WL-12) was conjugated with superparamagnetic iron oxide nanoparticles (SPIONs) to create the nanoprobe WL-12@Fe₃O₄. The nanoprobe's stability, biotoxicity, targeting ability, and in vivo magnetic resonance (MR) imaging effects were assessed and compared to non-targeted Fe₃O₄ nanoparticles. ΔT2 values and PD-L1 expression were measured in H226 and MSTO-211H tumor tissues over 4 weeks to analyze correlations.

Results: The WL-12@Fe₃O₄ nanoprobe demonstrated uniform distribution and a spherical shape, with a larger size (43.82 nm) and lower surface potential (-9.34 ± 0.54 mV) compared to Fe₃O₄ (32.67 nm, -20.20 ± 0.88 mV, P < 0.05). The XPS and FT-IR analysis results indicate the successful coupling of WL-12 with Fe₃O_4. It was well dispersed in serum and saline and showed no cytotoxicity or organ damage in vivo. The probe selectively accumulated in PD-L1-expressing MPM cells, especially MSTO-211H, and exhibited significantly higher uptake in high PD-L1-expressing H460 cells (930.22 ± 11.75 ng/mL) compared to low PD-L1-expressing A549 cells (254.89 ± 17.33 ng/mL, P < 0.05). Tumor iron levels in the WL-12@Fe₃O₄ group were significantly elevated (141.02 ± 17.33 μg/g) compared to controls (36.43 ± 3.56 μg/g, P < 0.05), with no significant differences in other organs (P > 0.05). The T2 values of H226 and MSTO-211H tumors decreased after probe injection, with ΔT2 values significantly higher in the targeted group than the nontargeted group (P < 0.05). ΔT2 values increased over 4 weeks, correlating strongly with PD-L1 expression (P < 0.05).

Conclusion: The PD-L1-targeted nanoprobe with MRI is a promising tool for noninvasive, real-time assessment of PD-L1 expression in MPM.