Molecules最新文献

The plant kingdom serves as a valuable resource for cancer drug development. This study explored the antitumor activity of different sub-fractions (hexane, dichloromethane and methanol) of U. gallii (gorse) methanol extract in glioblastoma (U-87MG and U-373MG) and neuroblastoma (SH-SY5Y) cell lines, along with their phytochemical profiles. Cytotoxicity was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays, and cell cycle arrest and apoptosis were assessed through flow cytometry and by measuring reactive oxygen species (ROS) and protein expression levels. D7 and D8 dichloromethane sub-fractions significantly reduced cell viability, triggered early apoptosis in SH-SY5Y and U-87MG cells and specifically increased ROS levels in U-87MG cells. Western blot analyses showed that D7 increased p53, caspase-3, caspase-8 and γH2AX expression in SH-SY5Y and U-87MG cells, while D8 specifically elevated p53 in SH-SY5Y cells and caspase-3 in both cell lines. In U-373 cells, D7 and D8 markedly reduced cell viability, with D8 inducing necrosis. Morphological changes indicative of apoptosis were also observed in all cell lines. Bioinformatic analysis of UHPLC-MS and GC-MS data tentatively identified 20 metabolites in D7 and 15 in D8, primarily flavonoids. HPLC-DAD confirmed isoprunetin and genistein as the most abundant in D7 and D8, respectively, both isolated and identified by NMR spectroscopy. Most of the flavonoids identified have been reported as antitumor agents, suggesting that these compounds may be responsible for the observed pharmacological activity.

The regioselectivity and molecular mechanism of the (3+2) cycloaddition reaction between E-2-(trimethylsilyl)-1-nitroethene and arylonitrile N-oxides were explored on the basis of the ωB97XD/6-311+G(d) (PCM) quantumchemical calculations. It was found that the earlier postulate regarding the regioselectivity of the cycloaddition stage should be undermined. Within our research, several aspects of the title reaction were also examined: interactions between reagents, electronic structures of alkenes and nitrile oxides, the nature of transition states, the influence of the polarity solvent on the reaction selectivity and mechanism, substituent effects, etc. The obtained results offer a general conclusion for all of the important aspects of some groups of cycloaddition processes.

Fruit processing by-products contain various classes of bioactive constituents, which may find applications as ingredients for foods, nutraceuticals or cosmeceuticals. This study explored the fractionation of lipophilic rowanberry pomace extracts isolated with pure supercritical CO₂ and its mixtures with a co-solvent ethanol by their on-line separation at subcritical conditions. Rowanberry pomace lipids were extracted with supercritical CO₂ (42.4 MPa, 53 °C) using 0-7% of ethanol, and then fractionated by reducing the first separator's (S1) pressure to 7 MPa and cooling it to 0, -10 and -20 °C to precipitate the 'heavier' fraction (HF). The second separator (S2) was depressurized at ambient temperatures to collect the 'lighter' fraction (LF). The yield of the LF increased by decreasing the S1 temperature and increasing the amount of the co-solvent. The concentration of β-carotene was increased in the LF by decreasing the S1 temperature and increasing the co-solvent concentration; at -20 °C it was 66.7% higher than in the non-fractionated extract. The concentrations of tocopherols and phytosterols were also remarkably higher in the LF. In total, 62 compounds were identified in the headspace volatile fraction of the LF, benzaldehyde and benzyl alcohol being the most abundant constituents. In conclusion, fractionation enabled us to obtain fractions with higher concentrations of the selected classes of lipophilic rowanberry constituents.

This study employed ultrasound-assisted extraction (UAE) to isolate polysaccharides from Lyophyllum decastes, which were subsequently fractionated into two components, LDP-A1 and LDP-B1, using DEAE cellulose-52 and Sephacryl S-500. The structural characteristics of the polysaccharides were preliminarily analyzed using high-performance liquid chromatography (HPLC), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Congo red staining. The results indicate significant differences between LDP-A1 and LDP-B1 in terms of molecular weight, monosaccharide composition, and structural features. LDP-A1 (2.27 × 10⁶ Da) exhibits a significantly higher molecular weight compared to LDP-B1 (9.80 × 10⁵ Da), with distinct differences in monosaccharide types and content. Both polysaccharides contain β-glycosidic bonds. LDP-B1 adopts a sheet-like structure with an amorphous internal arrangement and a triple-helix configuration, whereas LDP-A1 is rod-shaped, with a crystalline internal structure, and lacks the triple-helix configuration. In terms of biological activity, both polysaccharides exhibit certain activities, but LDP-B1 shows significantly stronger activity in antioxidant, hypoglycemic, anti-inflammatory, and anticancer effects. In summary, LDPs exhibit significant biological activity, especially outstanding performance in antioxidant, hypoglycemic, anti-inflammatory, and anticancer effects, proving their potential for development in functional foods and pharmaceuticals. Their unique structural characteristics and diverse biological activities provide a solid theoretical foundation for further exploration of LDPs in health promotion and disease prevention, opening up new research directions and application prospects.

Background: Raspberry leaf (RL; Rubus idaeus) is a by-product of raspberry cultivation and has been proposed to be a rich source of micronutrients and potential bioactive components, including polyphenols. However, the precise chemical composition of the non-nutrient (poly)phenols in RL has not been as extensively studied.

Objective: To evaluate the (poly)phenolic content of six RL samples from different geographical locations and to explore the impact of brewing duration on the levels of phenolic compounds available for absorption following consumption.

Methods: A total of 52 polyphenolic constituents were investigated in the RL samples using Liquid Chromatography-Mass Spectrometry (LC-MS), and RL tea samples were analysed for ellagitannins, flavonoids, and phenolic acids. Tea samples were extracted using 80:20 (v/v) methanol/acidified water (0.1% formic acid) to maximise polyphenol recovery, with two sonication steps (30 and 25 min), followed by centrifugation, filtration, and storage at -18 °C. Extractions were performed in triplicate for comprehensive profiling. Additionally, raspberry leaf tea (2 g) was brewed in 200 mL of boiling water at various times (0.5-20 min) to simulate standard consumption practices; this was also performed in triplicate. This approach aimed to quantify polyphenols in the brew and identify optimal steeping times for maximum polyphenol release.

Results: Raspberry leaf (RL) samples from six geographical sources were analysed, with 37 compounds identified in methanol and 37 in water out of the 52 targeted compounds, with only 7 compounds not detected in either methanol or water extracts. The analysis indicated that the total measured polyphenol content across the six samples from various sources ranged between 358.66 and 601.65 mg/100 g (p < 0.001). Ellagitannins were identified as the predominant polyphenolic compound in all RL samples, ranging from 155.27 to 394.22 mg/100 g. The phenolic acid and flavonoid concentrations in these samples exhibited a relatively narrow range, with the phenolic acids spanning from 38.87 to 119.03 mg/100 g and the flavonoids ranging from 125.03 to 156.73 mg/100 g. When brewing the tea, the 5 min extraction time was observed to yield the highest level of polyphenols (505.65 mg/100 g) (p< 0.001), which was significantly higher than that with shorter (409.84 mg/100g) and longer extraction times (429.28 mg/100 g). Notably, ellagic acid levels were highest at 5 min (380.29 mg/100 g), while phenolic acid peaked at 15 min (50.96 mg/100 g). The flavonoid content was shown to be highest at 4 min (82.58 mg/100 g).

Conclusions: RL contains a relatively high level of polyphenols, particularly ellagic acid; thus, its consumption may contribute to the daily intake of these health-beneficial non-nutrient components.

Catalytic alkane hydroxylation activities of the iron complex encapsulated into the micropore of the Y-type zeolite and mesoporous zeolites, the latter of which were obtained by the partial removal of aluminum and alkaline treatment, have been explored by using H₂O₂ as the oxidant. The iron complex with tris(pyridylmethyl)amine (=TPA) encapsulated into the micropore of the genuine Y-type zeolite was a more stable and effective cyclohexane hydroxylating heterogeneous catalyst compared to the corresponding copper analogue as well as the non-encapsulated homogeneous Fe-TPA complex. The chemical modification of the zeolite supports with the organic groups led to changing the catalytic activity depending on the size and the hydrophobic or hydrophilic nature of the added organic groups. When the content of water in the solvent was increased, the activity of the hydrophilic longer chain-modified catalyst was improved compared to that applied on the reaction with the non-aqueous solvent. The hydrophobic fluoroalkyl modifier located near the entrance of the micropore hindered the access of the substrate and aqueous H₂O₂ to the encapsulated iron complex site in the genuine Y-type zeolite. On the other hand, the hydrophobic modification effectively improved the activity of the catalyst with the zeolite support having higher amounts of mesopores. The synergistic effect of the wider bore diameters and the hydrophobic nature derived from the fluoroalkyl chains led to the concentration of the hydrocarbon substrate near the active iron complex.

Xanthone dimers, a distinctive class of natural metabolites renowned for their unique structures, are abundantly present in a diverse array of angiosperms, fungi, and lichens. These compounds not only exhibit remarkable diversity but also possess a broad spectrum of biological activities. In this comprehensive review spanning from 1966 to 2024, we synthesized the relevant literature to delve into the natural occurrence, biological potency, molecular structure and chemical diversity of xanthone dimers. The aim of this review is to serve as an insightful reference point for future scientific inquiries into xanthone dimers and their potential applications.

Resveratrol, a naturally occurring phenolic stilbene molecule, has been intensively researched for its anti-inflammatory, anticancer, antioxidant, antibacterial, and neuroprotective properties. However, due to its limited absorption and probable hepatotoxicity, it is difficult to employ directly as a medication, limiting its therapeutic applicability. Over the last five years, numerous structural changes in resveratrol have been widely studied, resulting in considerable improvements in pharmacological activity and drug availability. This work reviews the biological activities and structure-activity relationships (SARs) of resveratrol derivatives, with the goal of providing useful insights for the discovery of new resveratrol derivatives.

Spermidine is a natural autophagy-inducer and anti-aging compound. Herein, we investigated a potential autophagy-independent mechanism of spermidine, namely its capability to directly impede LDL oxidation, an early step in atherogenesis. In our in vitro-model, LDL oxidation was induced by the addition of CuCl₂ in the presence of increasing concentrations of spermidine, and the degree of oxidation of the lipid, as well as of the protein part of LDL, was measured. We found that spermidine concentration-dependently inhibited the production of lipid hydroperoxides, malondialdehyde, and oxidation-specific immune epitopes in the LDL particle, associated with decreased relative electrophoretic mobilities, respectively. For example, the LPO content was significantly lower when LDL was oxidized in the presence of 500 µg/mL spermidine (26.9 ± 1.6 nmol/mg LDL) than in the absence of spermidine (180.6 ± 7.7 nmol/mg LDL, p < 0.0001). When oxLDL was obtained under increasing spermidine concentrations, its cytotoxicity in EA.hy926 cells concentration-dependently decreased. Quantum chemical calculations show that the reaction between spermidine and hydroxyl radicals is exergonic. We conclude that spermidine is a direct inhibitor of LDL oxidation due to its capability to scavenge hydroxyl radicals. Thus, spermidine supplementation might be a suitable tool to impede atherogenesis and associated (cardio)vascular diseases. Further prospective clinical studies are needed to evaluate the potential atheroprotective/health-promoting effects of spermidine-rich diets.

III-nitrides are crucial materials for solar flow batteries due to their versatile properties. In contrast to the well-studied MOVPE reaction mechanism for AlN and GaN, few works report gas-phase mechanistic studies on the growth of InN. To better understand the reaction thermodynamics, this work revisited the gas-phase reactions involved in metal-organic vapor-phase epitaxy (abbreviated as MOVPE) growth of InN. Utilizing the M06-2X function in conjunction with Pople's triple-ζ split-valence basis set with polarization functions, this work recharacterized all stationary points reported in previous literature and compared the differences between the structures and reaction energies. For the reaction pathways which do not include a transition state, rigorous constrained geometry optimizations were utilized to scan the PES connecting the reactants and products in adduct formation and XMIn (M, D, T) pyrolysis, confirming that there are no TSs in these pathways, which is in agreement with the previous findings. A comprehensive bonding analysis indicates that in TMIn:NH₃, the In-N demonstrates strong coordinate bond characteristics, whereas in DMIn:NH₃ and MMIn:NH₃, the interactions between the Lewis acid and base fragments lean toward electrostatic attraction. Additionally, the NBO computations show that the H radical can facilitate the migration of electrons that are originally distributed between the In-C bonds in XMIn. Based on this finding, novel reaction pathways were also investigated. When the H radical approaches MMInNH₂, MMIn:NH₃ rather than MMInHNH₂ will generate and this is followed by the elimination of CH₄ via two parallel paths. Considering the abundance of H₂ in the environment, this work also examines the reactions between H₂ and XMIn. The Mulliken charge distributions indicated that intermolecular electron transfer mainly occurs between the In atom and N atom whiling forming (DMInNH₂)₂, whereas it predominately occurs between the In atom and the N atom intramolecularly when generating (DMInNH₂)₃.