Search Results (333)

Continuing our search for bioactive compounds in species from the Juncaceae family, we investigated Juncus tenuis. The structures of five previously undescribed phenanthrenes—tenuins A–E (1–5)—and 14 known phenanthrenes (6–19), along with other components, were isolated and characterized using nuclear magnetic resonance and high-resolution mass spectrometry measurements. The antiproliferative activity of all of the isolated phenanthrenes was evaluated against the human colorectal adenocarcinoma cell lines COLO 205 (doxorubicin-sensitive) and COLO 320 (doxorubicin-resistant), as well as a non-tumorigenic human fibroblast cell line (CCD-19Lu), using the MTT viability assay. Diphenanthrenes 4, 5, and 19 showed the most potent antiproliferative effects, with IC₅₀ values ranging from 7.60 to 17.32 μM; however, these compounds lacked selectivity toward cancer cells. To explore potential chemosensitizing properties, the synergistic effects of the phenanthrenes with the anticancer drug doxorubicin were also examined in the COLO 320 cells. Notably, compound 2 exhibited very strong synergism (CI = 0.021), indicating a highly potent interaction. These findings highlight J. tenuis as a valuable source of phenanthrenes and demonstrate the synergistic anticancer potential of natural phenanthrenes with doxorubicin, offering promising prospects for overcoming multidrug resistance in colorectal cancer therapy. Full article

The efficient synthetic routes and evaluates cytotoxic profiles of denitroaristolochic acids II–V (DAA-II–V) were demonstrated in this study. Based on retrosynthetic analysis, a modular synthetic strategy was developed through Suzuki–Miyaura coupling, Wittig reaction, and bismuth triflate-catalyzed intramolecular Friedel–Crafts cyclization to efficiently construct the phenanthrene core. Process optimization significantly improved yields: aryl bromide intermediate A reached 50.8% yield via bromination refinement, while arylboronic ester intermediate B overcame selectivity limitations. Combining Darzens condensation with Wittig reaction enhanced throughput, achieving 88.4% yield in the key cyclization. Structures were confirmed by NMR and mass spectra. CCK-8 cytotoxicity assays in human renal proximal tubular epithelial cells revealed distinct toxicological profiles: DAA-III and DAA-IV exhibited IC₅₀ values of 371 μM and 515 μM, respectively, significantly higher than the nitro-containing prototype AA-I (270 μM), indicating that the absence of nitro group attenuates but does not eliminate toxicity, potentially via altered metabolic activation. DAA-II and DAA-V showed no detectable cytotoxicity within assay limits, suggesting reduced toxicological impact. Structure–activity analysis exhibited that the nitro group is not essential for cytotoxicity, with methoxy substituents exerting limited influence on potency. This challenges the conventional DNA adduct-dependent toxicity paradigm, implying alternative mechanisms like oxidative stress or mitochondrial dysfunction may mediate damage in denitro derivatives. These systematic findings provide new perspectives for AA analog research and a foundation for the rational use and safety assessment of Aristolochiaceae plants. Full article

The development of alternative methods that link cellular and predictive toxicity to high-level toxicity is a key focus of current research within the framework of the 3Rs in animal experimentation. In this context, this study aimed to evaluate the previously developed in vitro approach using the zebrafish liver cell line (ZFL) for assessing bioaccumulation and biotransformation of the compound BDE-47, which is more hydrophobic than phenanthrene, and is the compound used in the previous study. For this purpose, experimentally, the internal concentrations in the cells (C_cell) and the exposure medium of both BDE-47 and its main metabolites were quantified at different exposure times by GC-MS. Additionally, the free bioavailable concentration (C_free) was determined with a solid-phase microextraction (SPME) experiment. With the aim of refine models, C_cell and C_free were also estimated using a predictive chemical distribution model (MBM). Bioconcentration factors (BCFs) were determined by relating all these values, as well as by toxicokinetic fitting and by in vitro–in vivo extrapolation modelling (IVIVE). The results showed a high concordance with the values obtained in vivo. Moreover, the study highlighted the importance of experimentally determining C_free and C_cell, as the predicted values can vary depending on the chemical, thereby influencing the BCF outcome. This variation occurs because models do not account for the absorption and biotransformation kinetics of the compounds. The data presented may contribute to refining predictive models. Full article

This paper presents the results of a study of the catalytic hydrogenation of phenanthrene using catalysts based on chrysotile modified with nickel and titanium (chrysotile/NiTi), as well as coal shale. Complex characterization of catalysts in terms of acid, texture and morphological properties was carried out. Pre-reduction in the catalysts has been found to increase the yield of partially and fully hydrogenated products, including tetrahydronaphthalene, trans-decalin and dihydrophenanthrene. Particular attention is paid to the role of coal shale as a donor source of hydrogen in thermolysis conditions. The results of hydrogenation revealed complex mechanisms of phenanthrene transformations, including partial saturation of aromatic rings, desulfurization and the formation of alkyl-substituted compounds. The obtained data emphasize the prospects of using the studied catalysts in the processes of processing heavy and solid hydrocarbon raw materials, which opens up opportunities for creating new technologies for the production of liquid fuel. Full article

Rhamnolipids and earthworm casts, as efficient and environmentally friendly biostimulants, influence the biodegradation of organic pollutants. However, it remains unclear how rhamnolipids and earthworm casts affect the anaerobic biodegradation of polycyclic aromatic hydrocarbons (PAHs). This work aimed to investigate the efficacy and mechanism of biostimulants on the anaerobic biodegradation of PAHs through PAH degradation, functional gene abundance, and bacterial community structure. The results revealed that both stimulants promoted the anaerobic degradation of typical PAHs, such as phenanthrene, pyrene, and benzo(a)pyrene. Rhamnolipids and earthworm casts promoted the degradation of phenanthrene and pyrene more significantly, with the degradation rate increasing by 13.75% and 16.92%, respectively, and the degradation rate of benzo(a)pyrene increased by 10.26% and 11.7%, respectively. The addition of rhamnolipids and earthworm casts significantly stimulated the abundance of functional genes (UbiD, UbiE) in bacterial communities, and this study indicated a strong association between the abundance of functional genes and PAH degradation efficiency. Furthermore, biostimulants altered the microbial community structure and affected microbial diversity and function. Earthworm casts significantly promoted the Azospirillum (0.02–20.17%) and Acinetobacter (0.01–15.70%) genera, which played an important role in the degradation process of PAHs. Therefore, these findings suggested that the enhancement of anaerobic biodegradation of PAHs by rhamnolipids and earthworm casts is probably due to an increase in abundance of both PAH-degraders and their degrading genes (UbiD, UbiE). This study could provide valuable insights for advancing the sustainable remediation of PAH-contaminated soils. Full article

The lower and middle Carboniferous shale sequences are one of the important potential hydrocarbon source rocks in the piedmont of the southwestern Tarim Basin, China (PSTB). Rock samples were collected from the lower and middle Carboniferous formations on the Kushanhe, Altash, and Aitegou outcrops in the PSTB with the intention of mapping the hydrocarbon molecules within these shale sources and disclosing the relevant geochemical implications. The ratios of Pr/Ph < 1.0 and DBT/P < 0.4 and the enrichment of C₂₃ tricyclic terpanoid indicate that the Carboniferous shale sources were deposited in a reducing and sulfate-poor marine setting with the contribution of terrestrial freshwater. Marine aquatic algae act as the major contributor, resulting in the formation of Type II₁ kerogen. The Carboniferous shale sequences contain abundant diamondoids with 2–4 cages with the predominance of methyldiamantanes, dimethyldiamantanes, and methyltriamantanes. Quantitative extended diamondoid analysis indicates the occurrence of carbonate-rich and carbonate-poor organic facies in the PSTB. Compared to the carbonate-poor facies, the carbonate-rich facies is relatively depleted in C₂₇ diasteranes and rich in gammacerane, C₂₇ regular steranes, and alkylated triamantanes. This indicates that it was deposited in the more salty and stratified water column but with less input of land higher plants. The clay catalysis effects are assumed to be responsible for the discrepancy in steranes and diamondoids. The Carboniferous shale sequences also contain abundant polycyclic aromatic hydrocarbons with 2–5 rings with the predominance of C_0–1-phenanthrenes, chrysenes, and benzofluoranthenes. Thermal maturity parameters associated with polycyclic aromatic hydrocarbons and diamondoids suggest that the Carboniferous shale sources have arrived at the late mature to highly mature stage. This study provides the detailed molecular fingerprints of the lower and middle Carboniferous shale source sequences and explores the underlying geochemical implications. This should be helpful for oil–oil and oil–source correlations and hence petroleum exploration activity in the PSTB. Full article

The present study investigated the combined effects of wheat straw biochar (BC) and biosurfactant rhamnolipid (RL) on the biodegradation kinetics of phenanthrene by indigenous microorganisms in agricultural soil, focusing on dynamic responses of both bioavailability and community structure. The combined treatment (BC + RL, 60.63%) significantly enhanced phenanthrene biodegradation compared to RL alone (54.74%) and the control (45.98%), while BC amendment alone (42.55%) notably inhibited biodegradation by reducing phenanthrene bioavailability despite increasing bacterial abundance, enzyme activity, and community diversity. Both RL and BC + RL treatments promoted bioavailability by transforming phenanthrene from tightly bound (very slowly desorbing fraction, F_vslow) to readily bioavailable fractions (rapidly and slowly desorbing fractions, F_rapid and F_slow), as revealed by sequential Tenax extraction. The RL-mediated increase in phenanthrene bioavailability to microbes by 11.93–17.90% via solubilization greatly enriched PAH-degrading bacterial genera and the nidA gene, contributing to enhanced biodegradation. The BC + RL combination outperformed the single application of RL in improving phenanthrene biodegradation due to their synergy in stimulating microbial population and activity (e.g., Bacillus, Massilia, Sphingomonas, and polyphenol oxidase) as a growth stimulus. These findings demonstrate that BC and RL co-application enhances PAH removal through improved bioavailability and optimized microbial communities, offering a promising strategy for soil bioremediation to ensure agricultural product safety. Full article

The development of efficient bioremediation technologies for polycyclic aromatic hydrocarbons contamination is a hot research topic in the environmental field. In this study, we found that the Mycobacterium sp., TJFP1, has the function of degrading low molecular weight PAHs, and further investigated its degradation characteristics using the PAH model compound phenanthrene as a target pollutant. The optimal growth and degradation conditions were determined by single-factor experiments to be 37 °C, pH 9.0, and an initial concentration of 100 mg/L phenanthrene. Under this condition, the degradation efficiency of phenanthrene reached 100% after 106 h of incubation, and the average degradation rate could reach 24.48 mg/L/day. Combined with whole genome sequencing analysis, it was revealed that its genome carries a more complete phenanthrene degradation pathway, including functional gene clusters related to the metabolism of PAHs, such as phd and nid. Meanwhile, intermediates such as phthalic acid were detected; it was determined that TJFP1 metabolizes phenanthrene via the phthalic acid pathway. Simulated contaminated soil experiments were also conducted, and the results showed that the removal rate of phenanthrene from the soil after 20 days of inoculation with the bacterial strain was about 3.7 times higher than that of the control group (natural remediation). At the same time from the soil physical and chemical properties and soil microbial community structure of two levels to explore the changes in different means of remediation, indicating that it can be successfully colonized in the soil, and as a dominant group of bacteria to play the function of remediation, verifying the environmental remediation function of the strains, for the actual inter-soil remediation to provide theoretical evidence. This study provides efficient strain resources for the bioremediation of PAH contamination. Full article

Designing bifunctional catalysts for efficient hydroisomerization of phenanthrene to alkyl-adamantane is a great challenge for producing high-density fuels. Herein, a bifunctional Pt catalyst was fabricated by developing hierarchical H-MSY-T zeolites with an NOA-co strategy. The influence of different mesopore template agents on the hierarchical structure of H-MSY-T zeolite was investigated. Effective regulation of pore structure and acid distribution of zeolites was achieved by adjusting the templating agents. The block copolymer P123 promoted the formation of mesoporous structures via self-assembly with a large mesopore centered at 8 nm. Large mesoporous structure and suitable distribution of Bronsted acid boosted the hydroisomerization of phenanthrene. The highest alkyl-adamantane yield of 45.9 wt% was achieved on the Pt/MSY-P1 catalyst and a reaction network of hydroisomerization was proposed. This work provides guidance to design highly selective bifunctional catalysts for the one-step hydroconversion of tricyclic aromatic hydrocarbons into high-density fuels. Full article

Heavy metals (HMs) or/and polycyclic aromatic hydrocarbons (PAHs) stress have significant adverse effects on the photosynthetic function and SPAD values of plants. Physiological integration is the typical feature of clonal plants, which can mitigate the adverse effects on ramets under heterogeneous stress. However, the sustainability of physiological integration between clones over prolonged stress durations, the dynamics of integration intensity and potential differences under various stress types remain unclear. This study examined the effects of three different heterogeneous stresses—cadmium (Cd), phenanthrene (Phe), and a combination of Cd and Phe (Cd + Phe) on the physiological integration of Zoysia japonica at different time points. The results indicate that physiological integration significantly enhances SPAD value, net photosynthetic rate (P_N), stomatal conductance (Cond), intercellular CO₂ concentration (C_i), transpiration rate (Tr), and water use efficiency (WUE). However, the physiological integration intensity diminishes with prolonged stress exposure. In addition, among different stress types, the initial integration intensity was highest under the highest toxicity conditions, it decreased most rapidly, resulting in the lowest integration intensity during the later stages of stress. To sum up, this study highlights the role of physiological integration in maintaining the photosynthetic function of clonal plants under heterogeneous stress and elucidates the temporal changes in integration intensity under different stress conditions. Full article

Medium-temperature pitch was obtained by vacuum distillation of coal tar from the Qarmet coke chemical production. To determine the composition of the organic constituent of the Qarmet coal tar, the component composition was analyzed via gas–liquid chromatography (GLC) methods. The analysis of the component composition of the organic component of coal tar showed that the content of naphthalene and its derivatives is 37.57%, acenaphthene—2.10%, dibenzofurane—3.60%, fluorene—4.63%, phenanthrene—8.63%, anthracene—2.29%, fluoranthene—4.56%, and pyrene—2.84%. It was found that in the obtained pitch sample, indicators such as the content of insoluble in toluene (41.86%), the softening temperature (85–91 °C), and the yield of volatile substances (1.5%) are more consistent with the standards for electrode pitch grade “V”. The composition of fractions in baking soda, soluble in toluene and quinoline, has been established. In the fractions of pitch soluble in toluene, 11 components were identified, the main of which re fluoranthene (11.71%), pyrene (10.13%), phenanthrene (7.31%), and benzopyrene (4.84%). Thus, based on the analyses carried out, it was found that the Qarmet resin is suitable for obtaining a V-grade electrode pitch, which can be used in the aluminum industry. Full article

Phenanthrenes, which are polycyclic aromatic hydrocarbons comprising three benzene rings, exhibit a diverse range of functions. These compounds are utilized in the synthesis of resins, plant growth hormones, reducing dyes, tannins and other products. Notably, phenanthrenes possess significant pharmacological properties, including anti-tumor, anti-inflammatory and antioxidant activities, offering broad prospects for development, particularly in the fields of medicine and health. Interestingly, although aristolochic acid (AA) is a potent carcinogen, its lactam analogs can kill cancer cells and exhibit therapeutic effects against cancer. This provides a promising strategy for the toxicity-effect transformation of phenanthrenes. In this paper, we reviewed 137 articles to systematically review the anti-tumor potential and toxic effects of natural phenanthrenes isolated from the 19th century to the present, thus offering references and laying a foundation for their further research, development and utilization. Full article

Plastics pose a significant threat to marine ecosystems, owing to their slow biodegradability. Microplastics (MPs), in particular, affect marine life and maricultural organisms and can enter the food chain via ingestion by marine organisms, leading to bioaccumulation in predators, including humans. This study assessed the toxic interactions between polystyrene microplastic particles (PSMPs) and cadmium (Cd) and phenanthrene (Phe) using marine bivalves. While PSMPs were non-toxic to Pacific oysters (Crassostrea gigas), the toxicity of Cd and Phe was concentration-dependent. In most conditions, PSMPs reduced the toxicity of Cd and Phe, but in simultaneous exposure, they acted as Cd messengers, altering the toxicity during the adult stage. This study confirms that PSMPs can interact with coastal environmental pollutants, thereby accelerating biotoxicity and posing a significant threat to marine wildlife, mariculture, and human health. It also highlights the need to assess MP toxicity in coastal environments and their interactions with pollutants. Full article

This study focuses on the preparation of a highly active surface-enhanced Raman spectroscopy (SERS) substrate, where Ag nanoparticles synthesized by the Lee–Meisel method are loaded onto the surface of GO@PVP nanoparticles through classical electrostatic attraction. The substrate was characterized by SEM and XPS analysis. The SERS-active substrate was utilized for the detection of phenanthrene in aqueous solutions, achieving a detection limit of 10⁻⁸ g/L (5.6 × 10⁻¹¹ mol/L). In comparison to conventional Raman spectroscopy, this method exhibits a significant reduction in the detection limit and holds promise for trace polycyclic aromatic hydrocarbons (PAHs) monitoring in environmental samples. Full article

The aim of this study is to assess the accumulation rates of polycyclic aromatic hydrocarbons (PAHs) and phthalic acid esters (PAEs) in the Nielisz Reservoir. Sediment traps were used at three sites: the upper (N1 station), central (N2 station), and near-dam (N3 station) zones, where they were installed at the bottom in the littoral zone of the reservoir at depths ranging from approximately 1.6 m to 2.5 m. Sampling took place from June to August 2019, and entrapped sediments were analyzed for 16 PAHs and 11 PAEs. Four PAHs, naphthalene (NAP), phenanthrene (PHE), benzo(b)fluoranthene (B(b)F), and benzo(a)pyrene (B(a)P), and two PAEs—di-n-butyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP)—were identified. Among PAHs, 5-ring compounds dominated, while DBP was the most common PAE. PAH and PAE concentrations in entrapped sediments showed both temporal and spatial variability, but no clear trends were established. The accumulation rate of Σ₄PAH ranged from 47.8 to 458 μg/m²d, with a decreasing trend from the inflow to the dam. The light-to-heavy PAH ratio suggests a pyrogenic origin. Σ₂PAE fluxes were lower, between 1.81 and 17.6 μg/m²d, with no clear spatial variation along the reservoir. Ecotoxicological analysis indicated that PAHs and PAEs could occasionally harm benthic organisms, mainly due to B(b)F. The deposition rates of both PAHs and PAEs are strongly linked to the accumulation of suspended particulate matter (SPM) and organic carbon, particularly of autochthonous origin. Additionally, the pH and salinity of the water significantly influence the accumulation rate of the studied contaminants, especially PAHs. Full article