Molecules最新文献

The 'wire-like' acetylenic moiety is an important building block in organic and coordination chemistry that can facilitate electron transfer in donor-acceptor compounds, contributing to the enhancement of their photophysical properties. 2,6-Bis-(thiazol-2-yl)pyridine (dtpy) functionalized with a 4-phenylacetylene group (Ph-C≡C-dtpy) was, for the first time, used for the preparation of [ReCl(CO)₃(Ph-C≡C-dtpy)] and [Pt(Ph-C≡C-dtpy)Cl]CF₃SO₃ in order to understand the properties derived from the use of the acetylenic substituent. The coordination ability of Ph-C≡C-dtpy toward Pt(II) and Re(I) centers was determined. All the studied compounds were characterized using FT-IR, ¹H NMR, and ¹³C NMR spectroscopies, elemental analysis and, in the case of the free ligand and rhenium(I) complex, single-crystal X-ray analysis was also used. Their electrochemical, photophysical, and thermal properties were compared with the previously described similar systems. The photoluminescence spectra of Ph-C≡C-dtpy, [ReCl(CO)₃(Ph-C≡C-dtpy)] and [Pt(Ph-C≡C-dtpy)Cl]CF₃SO₃ were investigated in solution and in the solid state at 298 K and 77 K. The experimental results were supported by the DFT and TD-DFT calculations. As a result of the introduction of the -C≡C- moiety into the organic ligand skeleton, the Re(I) and Pt(II) complexes display room-temperature emission. In the case of [Pt(Ph-C≡C-dtpy)Cl]CF₃SO₃, photoluminescence lifetime in a microsecond regime was observed, whereas nanosecond lifetime for [ReCl(CO)₃(Ph-C≡C-dtpy)] in solution is comparable to lifetimes previously observed for rhenium(I) compounds with 4-substituted dtpys.

The seeds of Corema album are considered a by-product in fruit processing. This study aimed to determine the oil contents in seeds and characterize their triacylglycerol contents through a comparative analysis using three extraction solvent systems: hexane (Soxhlet method), hexane-isopropanol (Hara-Radin method), and methanol-chloroform-water (Bligh-Dyer method). The extracts were analyzed by gas chromatography/mass spectrometry and HPLC. The composition of fatty acids and triacylglycerols was determined, as were the allocation of fatty acids across the sn-2 and sn-1,3 positions, tocopherol and tocotrienol profile, and melting behavior through differential scanning calorimetry. Furthermore, the atherogenicity (IA) and thrombogenicity (IT) cardiovascular health indices were also calculated. The oil predominantly contained unsaturated fatty acids, and α-linolenic acid made up 45.8% of the total, along with a reduced n-6/n-3 fatty acid ratio (0.75). The α-linolenoyl chain primarily occupied the sn-1,3 (45.9%) and sn-2 (39.1%) positions. γ-tocotrienol was the most abundant tocochromanol. The melting curve of oil suggests the presence of fractions with a low melting point, composed of triacylglycerols containing polyunsaturated fatty acids. The oil exhibits low values for IA and IT of 0.05 and 0.04, respectively. Corema seed oil has potential health benefits thanks to its rich composition in the essential fatty acid, α-linolenic acid, the low proportion of n-6/n-3 fatty acids, and the low values of IA and IT.

The dysregulation of immune responses are responsible for the development of several diseases, such as allergic and autoimmune diseases. The medications used to treat these conditions have numerous side effects, creating the need for new drugs. Physalins are natural compounds with various pharmacological activities already described. Here, we aimed to investigate the immunomodulatory effects of physalin F in mouse splenocytes and in a delayed-type hypersensitivity (DTH) model. In a cytotoxicity assay, physalin F had low cytotoxicity to mouse splenocytes in concentrations equal to or below 2 µM. It significantly inhibited lymphocyte proliferation in a concentration-dependent manner and reduced the production of cytokines, including IL-2, IL-4, IL-10, and IFN-γ, in activated splenocytes. The combined therapy of physalin F with dexamethasone was investigated in vitro, showing a synergistic action of the two compounds. Mechanistically, physalin F reduced calcineurin activity in concanavalin A-stimulated splenocyte cultures. Finally, in vivo, the intraperitoneal administration of physalin F in a DTH model reduced paw edema induced by bovine serum albumin immunization. Our results demonstrate the potential of physalin F as an immunosuppressive agent, to be used alone or in combination with glucocorticoids.

Triticum aestivum L. subsp. spelta (cv. Rokosz) and common winter wheat Triticum aestivum L. subsp. aestivum (cv. Arktis, Belissa, Estivus, Fidelius, Hondia, Jantarka, KWS Ozon, Linus, Markiza, Ostka Strzelecka, Pokusa) grown in an organic farming system were analyzed and compared. Furthermore, the productivity of four common wheat cultivars (cv. Fidelius, Hondia, Jantarka, KWS Ozon) grown under four different (organic, conventional integrated, and monoculture) farming systems was compared. Using UPLC-DAD-MS, UPLC-PDA-MS/MS, and TLC-DPPH^•, nine phenolic acids, nine alkylresorcinols, and their antiradical activity were identified and quantified. In the organic farming system, the highest yield was observed for T. aestivum L. subsp. aestivum cv. Fidelius (4.17 t/ha). Infections of wheat cultivars were low or at a medium level. The highest resistance to Fusarium fungi was shown by cv. Fidelius, which also exhibited the highest alkylresorcinol content and antioxidant capacity. The total phenolic acid content was highest in cv. Rokosz (1302.3 µg/g), followed by common winter wheat cultivars cv. Linus (1135.1 µg/g) and cv. Markiza (1089.6 µg/g). The potential of winter wheat cultivars for human health and their suitability for cultivation in different production systems was determined, showing significant differences in bioactive compounds depending on cultivars, systems, and years.

The art of designing coupling systems to drive reactions for endergonic synthesis is a subject of great interest in the scientific community, but it still presents major challenges. The aim of this kinetic study was to run simulations in COPASI 4.39 to test the behavior of hypothetical models for a system that couples two independent reactions, one exergonic and the other endergonic. In our computational study, we unraveled the qualitative and quantitative conditions that allow and benefit coupling, considering all possible reaction pathways within the network. Optimal conditions were reached by assigning favorable directionalities and low activation energies to six reaction steps within a network that featured twenty reaction steps. Moreover, different models were designed and tested in order to investigate the availability of coupling with different reaction steps.

Snakebites are a significant public health problem in many tropical and subtropical regions, causing extensive morbidity and mortality. Traditional snake antivenoms face multiple challenges, including allergenicity, high production costs, and logistical difficulties, highlighting the urgent need for new therapeutic approaches. This pilot study explores the potential of oligopeptides as therapeutic inhibitors targeting the neurotoxic sites of ammodytoxin A (AtxA; PDB: 3G8G) from Vipera ammodytes. We selected two sense oligopeptides to represent critical neurotoxic regions of AtxA as targets for inhibition by complementary antisense peptides. Utilizing a heuristic antisense peptide design based on the molecular recognition theory, we modeled two antisense oligopeptides as complementary counterparts for each sense oligopeptide. The modeled sense and antisense peptides were commercially synthesized, and their binding affinities were evaluated using spectrofluorometric titrations. The determined dissociation constants (K_D) were in the range of 1-10 μM for all sense-antisense pairs, revealing relatively strong binding affinities. Confirmation of sense-antisense peptide binding prompted further investigation into their potential binding to the native target protein through global docking simulations using the HPEPDOCK web server. The results highlight the applicability of molecular recognition theory in the development of antisense peptides that could change therapeutic strategies in various biomedical fields. Further studies are needed to investigate the therapeutic efficacy and broader applications of these peptides.

Transfer hydrogenation is a crucial technology for synthesizing fine chemicals and pharmaceuticals, offering improved safety and convenience over traditional hydrogen methods, although it typically requires external bases. While isopropanol is commonly used as a hydrogen source, methanol is superior but faces challenges due to its high dehydrogenation energy barrier, limiting its use under mild conditions. This study focuses on investigating the differences in the electrogenerated base-driven transfer hydrogenation of aromatic ketones in isopropanol and methanol solvents, using Mn(CO)₅Br and cyclohexanediamine derivatives as the catalyst. The research demonstrates that high enantiomeric excess (ee) values were obtained in isopropanol in the presence of chiral Mn-based catalysts, while only racemic products were observed in methanol. The results indicate a strong dependence of the catalytic pathway on the choice solvent: in isopropanol, the catalyst operates via a metal-ligand cooperative transfer hydrogenation, resulting in high ee values, whereas in methanol, transfer hydrogenation occurs through metal hydride transfer with no stereoselectivity.

This study investigates the content of some metals and metalloids in the flowers of three Aesculus cultivars (AHP, Aesculus hippocastanum pure species, with white flowers; AHH, Aesculus hippocastanum hybrid species, with pink flowers; and AXC, Aesculus × carnea, with red flowers) over a four-year period (2016-2019) using inductively coupled plasma optical emission spectrometry (ICP OES) and principal component analysis (PCA). The research focuses on assessing macro- and micro-elemental compositions, identifying variations in mineral uptake, and exploring potential correlations with soil composition. Results highlight significant differences in elemental profiles among the three species, despite similar total ash content. Potassium and phosphorus emerged as dominant macroelements, with AXC showing lower magnesium levels compared to AHP and AHH. Particularly intriguing was the detection of antimony in all cultivars, raising questions about its role and bioaccumulation pathways in floral tissues. Iron and aluminum concentrations varied significantly across species, indicating species-specific metal transport mechanisms. Nickel content showed temporal fluctuations, potentially influenced by climatic conditions and soil properties. PCA revealed distinct clustering patterns, linking elemental concentrations to specific species and years. This comprehensive analysis enhances understanding of metal absorption and distribution in ornamental plants, providing insights into their metabolic processes and potential implications for environmental monitoring and phytoremediation strategies.

St. John's wort (Hypericum perforatum) is a medicinal plant known for its bioactive compounds, including tocopherols and tocotrienols, which possess antioxidant and anti-inflammatory properties. These compounds play vital roles in the plant's metabolism and have potential applications in the cosmetic and pharmaceutical industries. However, the content of these compounds in different anatomical parts of the plant, as well as the influence of environmental factors, such as the year of collection, remain underexplored. This study examined the content of tocochromanols in H. perforatum leaves, flowers, and flower buds, collected in Poland during the years 2022-2024. The results revealed that tocopherols predominantly accumulated in the leaves, while tocotrienols were more abundant in the flowers and flower buds. The year of collection had a significant effect on tocopherol levels, while tocotrienol content showed lower sensitivity to environmental fluctuations, indicating their higher stability. St. John's wort can be considered a valuable source of biologically active compounds, especially tocotrienols, which exhibit higher stability and less susceptibility to environmental variability. The results underline the importance of considering both the plant's anatomical parts and the year of collection when aiming to maximize the production of bioactive compounds.

A chromogenic solvent extraction system for Fe(III) based on 4-nitrocatechol (4NC) and xylometazoline hydrochloride (XMH) was investigated. The optimum conditions for extraction spectrophotometric determination of iron were found. Under these conditions, the formula of the extracted complex was (XMH⁺)₃[Fe(4NC)₃] and the apparent molar absorption coefficient at λ_max = 464 nm was 1.9 × 10⁵ dm³ mol^-1 cm^-1 (4-fold enrichment). To validate the aforementioned formula and gather information about the spin state of the central Fe(III) ion, a combined experimental-theoretical approach was employed. This approach entailed the experimental determination of the 4NC:Fe and XMH:Fe molar ratios and the optimization of potential color-bearing structures utilizing the B3LYP/6-311G computational chemistry method. The effect of foreign ions was thoroughly examined, and a sensitive, simple, and inexpensive analytical procedure was proposed, which was successfully applied for determining iron in pharmaceutical and industrial samples.