Search Results (4,626)

We present a modular building block strategy for synthesizing phosphonated polyaromatic systems as an alternative to the conventional late-stage phosphonation of prefabricated aromatic scaffolds, which often requires harsh conditions and has limited tolerance for functional groups. A monophosphonated biphenyl building block was obtained via nickel-catalyzed phosphonation of dibromobiphenyl at 170 °C for three hours. This synthesis is more economical and milder than typical high-temperature palladium systems. In parallel, a borated pyrene derivative was prepared by Suzuki–Miyaura borylation. The final palladium-catalyzed Suzuki cross-coupling reaction produced the target compound, octaethyl(pyrene-tetrakis(biphenyl))tetrakis(phosphonate), Et₈-PyTPPE. Single-crystal X-ray diffraction reveals a centrosymmetric molecule that crystallizes in the triclinic space group P–1, with the inversion center located at the central C–C bond of the pyrene core. The pyrene unit is essentially planar, while the biphenylphosphonate arms are highly twisted relative to the core and to each other. The crystal packing is dominated by weak intermolecular interactions, and no significant π–π stacking is observed. Hirshfeld surface analysis shows that H···H (60.5%) and C···H (22.5%) contacts predominate, while O···H interactions (14.4%) with phosphoryl oxygen atoms represent the most relevant directed contacts. From photophysical investigations, Et₈-PyTPPE exhibits blue fluorescence (λ_em. = 452 nm) in solution and aggregation-induced red-shifted emission with nanosecond lifetimes in the solid state, confirming purely fluorescent behavior. Full article

This study examines the effects of flower storage duration and harvest time on the yield and evolution of the volatile composition of ylang-ylang (Cananga odorata forma genuina) essential oil. Oils were obtained from flowers by hydrodistillation immediately or after storage (4 h, 8 h, 24 h and 30 h) to investigate the effect of storage duration and from flowers picked at different schedules (07:00 a.m., 11:00 a.m. and 03:00 p.m.) to investigate the effect of the time of flower harvesting. The ylang-ylang oils were by analyzed by GC–MS. Storage duration had no significant effect on yield up to 8 h, whereas significant decreases occurred after 24 and 30 h. The amount of aromatic compounds decreased markedly with storage, from 73.66% in fresh petals to 57.02% after prolonged storage. Harvest time also influenced the distribution of oxygenated compounds, terpene hydrocarbons and several key volatiles. Overall, oils distilled within 0–8 h after harvest and obtained from flowers collected at 07:00 a.m. or 3:00 p.m. exhibited superior yields and chemical profiles compared with delayed distillation or midday harvest (11:00 a.m.). These results underline the importance of rapid processing and optimized harvest timing to preserve oxygenated fractions and essential-oil quality. Full article

Biologically controlling Microcystis aeruginosa blooms in saline–alkaline environments remains a major challenge in aquatic ecosystem management. Here, the algicidal performance of an indigenous algicidal bacterium, Bacillus cereus strain PT1 isolated from a sulfate-type saline–alkaline pond, against M. aeruginosa was evaluated, and the underlying metabolic mechanisms were elucidated using non-targeted metabolomics. PT1 exhibited pronounced, stable algicidal activity under saline–alkaline conditions, decreasing the algal cell density from 2 × 10⁶ to 1.25 ± 0.5 × 10⁵ cells mL⁻¹ within 4 days at a rate of 93.75 ± 2.5% (p < 0.05). The above results demonstrate that strain PT1 has a significant lytic effect on M. aeruginosa. Non-targeted liquid chromatography–mass spectrometry analysis identified 298 PT1-induced accumulated metabolic features, and the top 30 candidates comprised organic acids and aromatic compounds, including benzoic acid, coumarin, malonic acid, and signaling-related molecules, including indoleacetaldehyde and nitroprusside. These differential metabolites were associated with algicidal-related pathways, including quorum sensing, two-component systems, ABC transporters, and tryptophan metabolism, outlining a coordinated “regulation–transport–metabolic remodeling” framework. Our findings demonstrate the potential of the indigenous algicidal strain PT1 from saline–alkali ponds to control M. aeruginosa blooms. They also provide an important theoretical basis and data foundation for further elucidating the molecular characteristics of algae solubilizing activity under saline–alkali conditions and developing microbial agents for preventing and controlling Microcystis blooms in saline–alkali ponds. Full article

The occurrence and spatial distribution of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), fragrances, UV filters and photoinitiators were investigated in surface sediments of Nerbioi-Ibaizabal estuary between 2005 and 2013, in 2020. Samples were extracted by focused ultrasound solid–liquid extraction technique and analyzed by gas chromatography coupled with mass spectrometry. Total PAHs, PCBs, OCPs, musks, UV filters and photoinitiators concentrations ranged between not detected (n.d.) and 43000 ng g⁻¹, n.d. and 2500 ng g⁻¹, n.d. and 820 ng g⁻¹, n.d. and 880 ng g⁻¹, n.d. and 91 ng g⁻¹ and from nd to 120 ng g⁻¹, respectively. Hexachlorocyclohexanes (HCHs) were ubiquitous in the estuary, suggesting that these compounds, although banned, leach from landfills. The PCB concentrations showed a decreasing trend. Ecological risk assessments based on sediment quality guidelines (SQGs) and risk quotient (RQ) suggested semi-volatile organic compounds could represent a potential ecological risk in the Nerbioi-Ibaizabal estuary. Full article

In this study, sixteen secondary metabolites, including two chromones, four dibenzofurans, three lipids, three depsides, two aromatic compounds, a quinone, and a terpene, were detected in the methanol:acetone (1:1 v/v) extract of the lichen Hypotrachyna enderythraea (Zahlbr.) Hale, using High-Performance Liquid Chromatography coupled to Orbitrap Electrospray Ionization tandem Mass Spectrometry (HPLC-Orbitrap ESI tandem MS/MS). These metabolites were characterized by analysis of their exact molecular masses and corresponding fragmentation patterns. The retention times of the identified metabolites were compared with those of standard compounds, confirming the presence of naturally occurring bioactive compounds. Density Functional Theory (DFT) calculations were employed to investigate preferential deprotonation sites in representative polyprotic metabolites. All these findings may contribute to expanding the spectrum of compounds identified within the genus Hypotrachyna and to evaluating their potential biological activities. Full article

Human skin and hair act as multifunctional barriers but are highly sensitive to environmental pollutants originating from air, water, and cosmetic products. Epidemiological studies report that exposure to particulate matter (PM_2.5–PM₁₀), nitrogen oxides (NO_x), and volatile organic compounds increases the risk of skin and hair disorders. For instance, women in high-traffic areas (N = 211) show significantly more pigment spots and nasolabial wrinkles compared to those in rural areas (N = 189), indicating accelerated skin ageing. Children aged 9–11 exposed to PM₁₀, benzene, and NO_x exhibit increased incidence of atopic dermatitis. Systemic exposure to dioxins causes chloracne, while co-exposure to polycyclic aromatic hydrocarbons (PAHs) and UVA radiation elevates skin cancer risk. Psoriasis flares are associated with mean pollutant concentrations over the 60 days preceding flare events in 957 patients, and hyperpigmentation prevalence increases in populations exposed to traffic-related PM and ROS-inducing pollutants. Hair loss is linked to oxidative stress from PM and PAHs absorbed on hair fibers, with in vitro studies showing keratinocyte apoptosis in scalp hair follicles. This review evaluates natural adsorbents such as zeolites, clays, activated carbon, and polyphenol-rich plant extracts for anti-pollution cosmetic formulations. Adsorption capacities range from 60 to 150 mg·g⁻¹ depending on the pollutant, with removal efficiencies of 30–55% in model topical systems. Mechanisms include ion exchange, surface adsorption, hydrophobic interactions, and radical scavenging. Incorporating 2–5% w/w of these adsorbents in cosmetic formulations significantly reduces pollutant deposition on skin and hair. These findings support the development of evidence-based, sustainable anti-pollution cosmetic strategies that quantitatively mitigate environmental stressor effects. Full article

Most species belonging to the genus Artemisia are aromatic plants showing a broad diversity in their essential oil composition. Artemisia rutifolia, traditionally used in folk medicine, exhibits an atypical chemotype characterized by a high concentration of phenylbutanoids, in contrast to the profiles observed in other specimens of the same species. This study aimed to provide an in-depth chemical characterization of the phenylbutanoid-rich essential oil of A. rutifolia obtained from samples collected in the Middle Gobi province of Mongolia. Particular attention was devoted to the identification of the minor phenylbutanoids and a preliminary determination of the main contributors to the odor of the oil. Hence, the essential oil was fractionated by column chromatography and subjected to GC-MS/FID and GC-O/FID analyses. Camphor, 1,8-cineole, and 4-phenylbutan-2-one were identified as the dominant compounds, the latter being the main odorant responsible for the typical fresh-fruity smell of the plant. Moreover, α- and β-thujones were absent, and seven previously unreported 4-phenylbut-2-yl esters were unambiguously identified through combinatorial synthesis. These findings highlight the chemical distinctiveness of the Middle Gobi chemotype and support its potential for industrial essential oil production due to its high yield, lack of thujones, and pleasant fresh aroma. Full article

Volatile organic compound (VOC) emissions from industrial parks are a crucial source of urban air pollution. This study assessed VOC emissions and their impact on secondary pollution from three key industries—packaging and printing, pharmaceutical manufacturing, and furniture manufacturing—in a typical industrial park in the Guanzhong region of China. The results revealed considerable variation in organized outlet VOC concentrations between the different industries, with the highest level observed in furniture manufacturing (3449.9 ± 437.6 µg/m³) and the lowest level discovered for pharmaceutical manufacturing (410.9 ± 205.5 μg/m³). The VOCs were mainly aromatics (40.7%) and alkanes (21.8%), with pentane, isopentane, xylene, and ethylbenzene the most abundant species. Although organized emissions (1151.6 t/y) constituted the primary source of emissions, fugitive emissions (358.1 t/y) remained a major contributor and primarily contributed aromatics and alkanes. Critically, reactivity-based assessment demonstrated that alkenes and aromatics were the principal contributors to the ozone formation potential (>80%). With regard to the secondary organic aerosol formation potential, aromatics were overwhelmingly dominant, accounting for approximately 87% of the total potential, with xylene and ethylbenzene in furniture manufacturing alone contributing 72.9%. The findings highlight the importance of prioritizing controls on highly reactive alkenes and aromatics. Fugitive emission management during storage, mixing, and curing stages should be enhanced and solvents should be substituted to effectively control VOC emissions in industrial parks. Full article

Background: Inhibition of histone deacetylase is a highly sought-after objective in the fight against cancer. Thus, the development of innovative HDAC inhibitors with significantly higher potency than SAHA against specific cancer cell types represents complex and demanding work. Method: The utilization of the underexplored and privileged scaffold 4-chlorothieno[2,3-b]pyridine as a cap tethering diverse aliphatic and aromatic linkers, followed by the screening of both cellular and enzymatic activities, is undertaken in this study. Results: Compounds 7a and 9a demonstrated impressive mean GI₅₀ values of 2.15 µM and 1.89 µM, respectively. Both compounds reduced caspase-3 levels in RPMI-8226 cells, suggesting induction of apoptosis. Compound 7a showed remarkable IC₅₀ values of 0.37 µM, 0.58 µM, and 0.70 µM against HDACs 1, 4, and 6, respectively, consistent with the cellular assay. Additionally, compound 7a exhibited a selectivity index of 11 for RPMI-8226 cells over PBMCs, reflecting its high selectivity and potential safety. Moreover, ADMET prediction tools indicated that compounds 7a and 9b may have more favorable pharmacokinetic properties than the gold-standard HDAC inhibitor, SAHA. Conclusions: Further study and exploration of the derivatives of compounds 7a and 9a can lead to further advancement in the development of potent HDAC inhibitor anticancer drugs. Full article

Residual lignin generated by pulp, paper, and biorefining industries is commonly burned for energy, despite its potential as a renewable source of aromatic compounds. Studies focusing on microbial lignin degradation contribute to lignin valorization and represent a sustainable strategy to enhance biomass circularity. Here, we report the isolation of Klebsiella sp. IL2_9 from a ruminal consortium and demonstrate its ability to degrade and metabolize organosolv lignin. After 24 h of cultivation, the strain removed 22% of the initial lignin content. FTIR analysis revealed alterations in functional groups associated with guaiacyl and syringyl units, indicating structural modification of the polymer. GC–MS analyses further showed the consumption of lignin-derived aromatics, including vanillin, 2-aminobenzoic acid, and 4-hydroxybenzoic acid, along with the formation of vanillyl alcohol and phenyllactic acid derivatives. Overall, these findings highlight the potential of Klebsiella sp. IL2_9 as a promising biotechnological candidate for lignin valorization under anaerobic conditions. Full article

Wood products made from Manchurian ash are widely used as furniture and decorations, particularly waterborne-coated Manchurian ash (Fraxinus mandshurica Rupr.). However, while waterborne coatings offer less air pollution, their odor emission dynamics under different environmental conditions remain poorly understood. To address these gaps, this study systematically analyzed 28-day volatile organic compounds (VOCs) and very volatile organic compounds (VVOCs) release profiles under controlled temperature, relative humidity, and air exchange rate-to-loading factor ratios (AER/Ls), using thermal desorption–gas chromatography–mass spectrometry/olfactometry (TD-GC-MS/O). Eighteen key odor-active compounds (OACs) were identified, comprising 11 wood-derived and seven coating components, exhibiting eight odor attributes: disinfectant-like, aromatic, tobacco-like, unpleasant, vinegar-like, flowery, sweety, and alcohol-like. The dominant attributes were disinfectant-like and aromatic. The results showed that temperature accelerated release rates and shortened equilibrium time, while increasing concentrations and odor intensity. Relative humidity prolonged equilibrium, with stage-dependent concentration effects, yet consistent odor intensity rise. Higher AER/L reduced equilibrium time and concentrations through dilution-dominated dynamics despite accelerated release rates from increased pressure differentials. These findings indicated that synergistic high-temperature (40 °C)/high-humidity (60% RH) conditions accelerate odorant emission, while optimized ventilation (AER/L 0.5 m³·m⁻²·h⁻¹) ensures effective mitigation. The findings will inform strategies to reduce odor impact and advance eco-efficient finishing technologies for wood products. Full article

A retrospective analysis of atmospheric volatile organic compounds in urban Beijing during spring 2017–2019 and 2025 reveals a profound transition in pollution characteristics following long-term control policies. Integrating field observations with positive matrix factorization (PMF), results reveal a fundamental atmospheric transition toward mobile source predominance and reduced chemical reactivity. Total volatile organic compound concentrations declined by 31.0% (to 23.7 μg/m³), driven by a massive 90.7% reduction in aromatics. Conversely, gasoline vehicle exhaust surged to constitute 66.9% of total volatile organic compound mass. This shift altered the chemical reactivity pattern: alkenes replaced aromatics as the primary drivers of ozone formation potential (46.4%), yet residual aromatics continued to dominate secondary organic aerosol formation potential (83.3%). Crucially, a coordinated total volatile organic compounds:NOx reduction ratio of 0.48:1 compared to 2017 successfully lowered spring O₃ levels by 8.4%. These findings substantiate the efficacy of past synergistic controls but emphasize that future deep abatement must prioritize targeting high-reactivity alkenes from mobile sources and residual solvent-based aromatics. Full article

The complex contamination characteristics and potential health risks of polycyclic aromatic hydrocarbons (PAHs) and their derivatives remain poorly understood. In this study, a comprehensive analysis of 16 parent PAHs and 34 derivatives was conducted in outdoor dust samples collected from a residential area constructed on an abandoned petrochemical site. The results showed that the total concentrations of PAHs, oxidized PAHs, nitro-PAHs, brominated PAHs, and chlorinated PAHs were in the ranges of 75.3–991 ng/g, 9.27–142 ng/g, 1.68–265 ng/g, 15.2–100 ng/g, and 1.23–14.8 ng/g, respectively. Additionally, the non-target screening analysis identified 29 potential aromatic compounds in dust samples. Toxicity assessment indicated that several PAH derivatives and newly identified compounds exhibited stronger acute toxicity than PAHs (ECOSAR model prediction). Incremental lifetime cancer risk (ILCR) values of target compounds ranged from 1.54 × 10⁻⁷ to 2.95 × 10⁻⁶ for adults and from 5.08 × 10⁻⁸ to 9.75 × 10⁻⁷ for children. Oral ingestion was identified as the dominant exposure pathway, accounting for 83.5% of total exposure, followed by dermal contact (16.5%). Overall, these findings highlight the complexity of human exposure to PAHs and related aromatic contaminants in petrochemical-impacted residential areas and underscore the need for continued attention to their associated environmental and health risks. Full article

Waste lignin from the hydrolysis of lignocellulosic materials is an abundant but underused by-product of the pulp and biorefinery industries. Phenolic compounds derived from lignin, rich in aromatic structures, show strong antioxidant potential and can be applied in polymer stabilization, food, and medical fields. This study evaluated the radical-scavenging activity of phenolic fractions obtained from alkaline-treated waste lignin against DPPH● and ABTS•⁺, using Trolox as a reference. Both spectrophotometric and electrochemical techniques were employed, providing deeper insight into the underlying mechanisms. Depending on the assay, the phenolic extracts demonstrated substantial radical-scavenging capacity, in some cases matching or surpassing that of Trolox. This behavior was linked to electron/proton transfer pathways, radical reactivity, and solubility effects. The combined use of multiple antioxidant tests offered a comprehensive characterization of the bioactivity of lignin-derived phenolics and supports their potential as sustainable sources of antioxidant compounds within a circular economy framework. Furthermore, the study examined how toluene-extracted phenolics affect the thermo-oxidative stability of model polyurethane films. Incorporating small amounts (1%, 3%, 5%) into the polymer matrix showed that a 1% loading provides the most effective stabilization. At higher concentrations, however, additional oxidative processes seem to be activated, as indicated by FTIR measurements and thermogravimetric analysis. Full article

CD38 is a multifunctional enzyme that plays a pivotal role in NAD⁺ metabolism and calcium signaling, and its abnormal activity is closely associated with multiple myeloma, age-related metabolic decline, neurodegenerative diseases, and other disorders. Although monoclonal antibodies such as daratumumab have been approved for clinical application, their inherent limitations necessitate the development of novel small-molecule CD38 inhibitors. In this study, we employed DNA-encoded library (DEL) technology for the high-throughput screening of CD38 inhibitors, using a DEL library containing more than 100,000 unique compounds to screen against recombinant human CD38. A total of 1043 enriched compounds were initially identified, and after rigorous validation and screening to exclude non-specific binding and previously reported active compounds, eight hit compounds with diverse chemical scaffolds were obtained, among which Fenbendazole—a clinically approved antiparasitic drug—was included. Surface plasmon resonance (SPR) assays confirmed the direct binding of these hit compounds to CD38, with dissociation constants (KD) ranging from 7.74 × 10⁻⁵ M to 2.15 × 10⁻⁴ M. Fluorescence-based enzymatic activity assays demonstrated that these compounds exert dose-dependent inhibitory effects on both the hydrolase (with ε-NAD as substrate) and cyclase (with NGD as substrate) activities of CD38. Further structure–activity relationship (SAR) analysis of Fenbendazole analogues revealed the critical structural features that regulate CD38 inhibitory potency, and Flubendazole was found to exhibit excellent inhibitory activity, with an IC₅₀ of 14.78 ± 4.21 μM against CD38 hydrolase and 26.31 ± 3.40 μM against cyclase. Molecular docking and 100 ns molecular dynamics (MD) simulations further elucidated the molecular mechanism of CD38 inhibition by lead compounds, confirming that van der Waals interactions are the main driving force for the binding of small-molecule ligands to CD38, with conserved aromatic residues in the active site mediating ligand recognition. This study validates DEL technology as an efficient and reliable platform for the discovery of CD38 inhibitors, and the identified lead compounds—especially Fenbendazole and its analog Flubendazole—provide valuable molecular scaffolds for the further structural optimization of CD38 inhibitors. These findings lay a solid foundation for the development of novel therapeutic agents for the treatment of CD38-associated diseases. Full article