Polyaromatic Hydrocarbons (PAHs): Structures, Synthesis and their Biological Profile

Gestational Exposure to Phenanthrene Induces Superfluous Fibrosis and Calcification and Metabolic Imbalance of the Placenta in Mice

The placenta is a vital organ that facilitates maternal-fetal circulation, ensuring proper fetal development. Phenanthrene (Phe), a typical low-molecular-weight polycyclic aromatic hydrocarbon, is widely present in the environment and food. In this study, pregnant mice were exposed to Phe (0, 0.6, 6, and 60 μg/kg of body weight) via gavage every 3 days from pregnancy day 0.5 (PGD 0.5) for a total of six exposures during pregnancy. Placentas were collected on PGD of 18.5 for analysis. The results showed that Phe exposure altered placental structure and function, inducing trophoblast thickening at low doses (0.6 μg/kg) but thinning at higher doses (6 and 60 μg/kg), reducing blood cell density in the placental labyrinth, disrupting metabolite composition, causing oxidative damage, and leading to excessive fibrosis and calcification. Molecular analysis revealed that PCNA was significantly upregulated in the 0.6 μg/kg group and downregulated in 6 and 60 μg/kg groups, indicating an initial compensatory proliferative response at low doses and impaired placental proliferation at higher doses, while Bad was abnormally accumulated in trophoblasts and dose-dependently upregulated, along with decline in antioxidant capacity. Meanwhile, increases in protein levels of TGF-β1, Smad2, p-Smad2, Smad1/5/9, p-Smad1/5/9, BMP2, TIMP1, Runx2, Collagen I, and SMA, and a decrease in MMP1 level was observed. These findings suggested that Phe exposure during pregnancy induced activation of the TGF-β/Smad2 pathway and BMP2/Smad1/5/9/Runx2 pathway, which might further lead to excessive fibrosis and calcification. The abnormally increased fibrosis and calcification, together with the oxidative damage, further elevated cellular apoptosis, destroyed the structure of the placenta, and reduced blood cell counts, impairing placental exchange efficiency and leading to systemic metabolic imbalances, which might further impair the health of their offspring.

Transforming beef quality through healthy breeding: a strategy to reduce carcinogenic compounds and enhance human health: a review

The presence of carcinogenic substances in beef poses a significant risk to public health, with far-reaching implications for consumer safety and the meat production industry. Despite advancements in food safety measures, traditional breeding methods have proven inadequate in addressing these risks, revealing a substantial gap in knowledge. This review aims to fill this gap by evaluating the potential of healthy breeding techniques to significantly reduce the levels of carcinogenic compounds in beef. We focus on elucidating the molecular pathways that contribute to the formation of key carcinogens, such as heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), while exploring the transformative capabilities of advanced genomic technologies. These technologies include genomic selection, CRISPR/Cas9, base editing, prime editing, and artificial intelligence-driven predictive models. Additionally, we examine multi-omics approaches to gain new insights into the genetic and environmental factors influencing carcinogen formation. Our findings suggest that healthy breeding strategies could markedly enhance meat quality, thereby offering a unique opportunity to improve public health outcomes. The integration of these innovative technologies into breeding programs not only provides a pathway to safer beef production but also fosters sustainable livestock management practices. The improvement of these strategies, along with careful consideration of ethical and regulatory challenges, will be crucial for their effective implementation and broader impact.

Occurrence and Risk Assessment of Polycyclic Aromatic Hydrocarbons in the Surface Water of Budhabalanga River Estuary, Chandipur, East Coast of India

The present study was carried out to assess the occurrence and ecological risk assessment of 16 priority polycyclic aromatic hydrocarbons (PAHs) in the Budhabalanga river estuary and coastal stretch of Chandipur. The range of PAH concentration varied between 19.5 and 1206 ng L-1. The ecological risk assessment of individual PAHs and ∑PAHs was calculated using the risk quotient and toxic equivalency factor method. Low molecular weight PAHs contributed towards ecological risk burden in comparison to high molecular weight PAHs. PAH diagnostic ratio suggested the presence of both pyrolytic and petrogenic origin for the observed PAHs. Pearson correlation and PCA plot clearly show interdependency between all PAHs and stations sampled.

Development of Aromatic Organic Materials for High-Performance Lithium-Ion Batteries: Strategies, Advances and Future Perspectives

Ever since lithium-ion batteries (LIBs) were successfully commercialized, aromatic compounds have attended every turning point in optimizing electrolytes, separators, and even electrode materials. However, the contribution of aromatic compounds has always been neglected compared to other advanced materials. At the same time, designing next-generation LIBs with higher flexibility, solid-state electrolytes, high energy density, and better Coulombic Efficiency (CE) has imposed stricter duties on aromatic components. In this review, we first systematically introduce the history of aromatic compounds that promote the development of LIBs. Typical applications of aromatic compounds in LIBs (e.g., separators, electrolytes, binders, and electrodes) are discussed in detail, and corresponding design characteristics are systematically analyzed. Finally, we suppose conjectures and prospects orientally designing aromatic compounds in the next generation LIBs.

The PM2.5 component, benzo[b]fluoranthene, may contribute to the pathogenesis of membranous nephropathy by activating phosphoinositide 3-kinase/protein kinase B pathway and causing podocyte pyroptosis

Membranous nephropathy (MN) is the main type of adult nephrotic syndrome, and its prevalence is increasing annually. An increasing number of studies have suggested that the pathogenesis of MN is related to 2.5-μm particulate matter (PM2.5), but the underlying mechanism has not been elucidated fully. Elucidating this mechanism can help prevent and treat MN. The constituents of PM2.5 vary from place to place; hence, the component responsible for PM2.5-related MN is still unclear. This study investigated the effects of benzo[b]fluoranthene (BbF), a PM2.5 component, on pyroptosis and phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signalling pathway in Sprague-Dawley rats and mouse podocytes. The organic constituents of BbF in PM2.5 can enter the circulatory system through the lungs and act on the kidneys to cause kidney damage, possibly because BbF activates the PI3K/AKT pathway and causes podocytes to undergo pyroptosis.

Elucidating the synergistic role of hybrid peptide from Burkholderia cepacia enzymes in biodegradation of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are hazardous environmental contaminants emerging from industrial activities and fossil fuel combustion, posing risks to human health and ecosystems. Biodegradation offers a sustainable approach to mitigating PAH pollution, and here we investigated the efficacy of a peptide hybrid of laccase and O-methyltransferase enzymes from the bacterium Burkholderia cepacia in PAH degradation. Both enzymes demonstrated stability with an instability index below 40, indicating suitability for environmental application. Following active site prediction, the 3D structure of the peptide hybrid, consisting of 71 amino acids, was modelled using trRosetta, achieving a high-quality structure with an ERRAT score above 97%. Further bioinformatic analysis confirmed the hybrid's non-allergenic and non-virulent properties. Molecular docking studies revealed a robust binding affinity above - 9 kcal/mol, highlighting this peptide hybrid's potential for effective PAH degradation and suggesting its promise as an eco-friendly bioremediation agent for PAH-contaminated sites.

Prediction of π-electronic energy and physical properties of benzenoid hydrocarbons using domination degree based entropies

This study introduces a novel approach to calculating graph entropies using topological indices, inspired by Shannon's entropy concept. These entropies, as information-theoretic measures, are applied to evaluate the structural properties of chemical graphs. Graph theory is utilized to examine correlations between specific chemical properties and graph entropy measures. Within this framework, several physicochemical and quantum properties, including boiling point, enthalpy, molecular weight, and π-electronic energy are analyzed. Certain new graph entropy measures, termed domination entropies, are introduced based on domination topological indices and computed for 29 benzenoid hydrocarbons. Additionally, a QSPR analysis is conducted to investigate the linear and multilinear relationships between these entropies and the physicochemical properties, as well as the π-electronic energy of the hydrocarbons. The predictive accuracy of these new domination entropies is confirmed through various statistical tools.

Occurrence, formation mechanism, and health risk of polycyclic aromatic hydrocarbons in barbecued food

Polycyclic aromatic hydrocarbons (PAHs) show negative impacts on human health. Dietary intake is the predominant way for PAH exposure, of which barbecued food is a crucial contributor. This review aims to provide a comprehensive insight into the formation mechanism, influencing factors, mitigation strategies, and health risks of PAHs in barbecued food. PAHs in barbecued food are formed by Hydrogen abstraction and acetylene addition (HACA) mechanism, Diels-Alder reaction and Maillard reaction, which was influenced by heat source, temperature, cooking time, and the meat type. There are significant differences in PAH concentrations in different barbecued foods, where chrysene dominates among the selected PAH species. To reduce PAHs formation, adding marinades and adopting alternative cooking methods are suggested, which effectively reduce PAH levels by 53 -89 %. In addition, it is estimated that people in countries such as Pakistan has an incremental lifetime cancer risk (ILCR) over 10-5 via barbecued food consumption, indicating potential health risk. This work highlighted that regular monitoring of PAH levels in barbecued food and dynamic modification of relevant safety limits are recommended to ensure food safety.

Leveraging Antarctic psychrotolerant fungi for PAH biodegradation, unveiling key factors influencing the process

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants, detected even in remote regions such as the Antarctic, Arctic, and Tibetan Plateau. Thus, understanding their biodegradation processes at low temperatures is crucial. Therefore, the potential of fungal strains from the Antarctic to biodegrade PAHs was explored. Experiments were performed in a nutrient medium with 100 mg.L-1 PAH, from 0 to 42 days at 120 rpm and 10-20 °C. Among the nine fungal strains assessed, eight demonstrated a statistically significant reduction in residual anthracene concentration (ranging from 58.1 to 92.9 mg.L-1) compared to the killed-cell control (102.4 ± 4.7 mg.L-1). Furthermore, the most efficient strain, Schizophyllum sp. LAMAI 2452, achieved a greater reduction in residual anthracene concentration compared to a consortium of six filamentous strains. Experimental design indicated that higher temperatures (20 °C) significantly enhanced the biodegradation efficiency of the best-performing strain and a consortium of three yeasts. In contrast, the consortium of six filamentous strains performed optimally at lower temperatures (10 °C), whereas pH levels did not significantly affect the biodegradation process. The assessed consortium biodegraded all the evaluated PAHs (anthrone, anthraquinone, acenaphthene, acenaphthylene, acenaphthenol, phenanthrene, and pyrene), and oxygenated and nitrogenated derivatives were identified as metabolites, contributing to a better understanding of the fate of these compounds. In summary, these biocatalysts effectively biodegraded different PAHs, providing insights into PAH degradation in extreme environments like Antarctica, while also opening avenues for discovering new biocatalysts for low-temperature processes.

Selenium-containing metallodrug overcomes cervical cancer radioresistance through physical-chemical dual sensitization

Radiotherapy is an important treatment for cervical cancer, but the efficacy of radiotherapy is often reduced in clinical practice owing to high frequency and high dose radiation leading to radiotherapy resistance. The development of efficient and low-toxicity radiotherapy sensitizers to reduce radiation dose is an effective strategy. Therefore, based on the existing radiotherapy sensitizers responding to radiophysical sensitization radiotherapy, we propose to design radiotherapy sensitizers with enzyme-mimicking and dual physical-chemical sensitization properties. In this work, we constructed Ru-Se complexes with cytochrome P450 enzyme-mimicking properties. On the one hand, the high concentration of ROS in tumor cells, along with the complexes, catalyzed the oxidation of intracellular active substances, breaking the redox balance of the cells and chemically sensitizing radiotherapy; on the other hand, the high atomic numbers of ruthenium and selenium responded to X-rays and physically sensitized radiotherapy. Experimental results demonstrated that the Ru-Se complexes can efficiently mimic cytochrome P450 enzyme activity and simultaneously respond to radiation dual sensitization radiotherapy, causing the expression of intracellular DNA damage response proteins. Thus, inhibition of repair protein expression overcomes radiotherapy resistance. This work provides a new idea for the development of efficient radiation sensitizers in the future.

Synthesis and characterization of allomelanin model from 1,8-dihydroxynaphthalene autooxidation

In this work a novel method for synthesis of 1,8-dihydroxynaphthalene melanin was presented, as well as the physicochemical properties, molecular structure, and characteristics of the pigment. The proposed synthesis protocol is simple and cost-effective with no enzymes or catalysts needed. The final product is not adsorbed on any surface, since the pigment is the result of autooxidation of 1,8-dihydroxynaphthalene. Performed analyses revealed that the solubility, optical and paramagnetic properties are typical for melanins, and in the EPR spectra an unusual hyperfine structure was observed. The molecular structure of the pigment consists of three different layers forming polar and non-polar surfaces. Additionally, the presence of ether bonds presence was revealed. The developed method creates new opportunities for melanin research and eliminates the need to extract melanins from biological samples, which often lead to structural changes in isolated melanins, which undermines the reliability of analyses of the properties and structure of these polymers. On the other hand, the ubiquity of melanins in living organisms and the diversity of their biological functions have let to the growing interest of researchers in this group of pigments. The analyses carried out show that the obtained synthetic DHN polymer can be considered as a model DHN-melanin in mycological studies and material research.

Effects of particulate air pollution on BPDE-DNA adducts, telomere length, and mitochondrial DNA copy number in human exhaled breath condensate and BEAS-2B cells

Traffic-related particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) have been linked to respiratory diseases and cancer risk in humans. Genomic damage, including benzo[a]pyrene diolepoxide (BPDE)-DNA adducts as well as alterations in telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN) are associated with respiratory diseases. This study aimed to investigate the association between exposure to traffic-related particulate pollutants and genomic damage in exhaled breath condensate (EBC) in human subjects and a bronchial epithelial cell line (BEAS-2B). Among the 60 healthy recruited subjects, residents living in high-traffic-congested areas were exposed to higher concentrations of PM2.5 (1.66-fold, p < 0.01), UFPs (1.79-fold, p < 0.01), PM2.5-PAHs (1.50-fold, p < 0.01), and UFPs-PAHs (1.35-fold, p < 0.05), than those in low-traffic-congested areas. In line with increased exposure to particulate air pollution, the high-traffic-exposed group had significantly increased BPDE-DNA adducts (1.40-fold, p < 0.05), TL shortening (1.24-fold, p < 0.05), and lower mtDNA-CN (1.38-fold, p < 0.05) in EBC. The observations in the human study linking exposure to PM2.5, UFPs, PM2.5-PAHs, and UFPs-PAHs with the aforementioned biological effects were confirmed by an in vitro cell-based study, in which BEAS-2B cells were treated with diesel exhaust particulate matter (DEP) containing fine and ultrafine PM and PAHs. Increased BPDE-DNA adducts levels, shortened TL, and decreased mtDNA-CN were also found in treated BEAS-2B cells. The shortened TL and decreased mtDNA-CN were in part mediated by decreased transcript levels of hTERT, and SIRT1, which are involved in telomerase activity and mitochondrial biogenesis, respectively. These results suggest that exposure to traffic-related particulate pollutants can cause genomic instability in respiratory cells, which may increase the health risk of respiratory diseases and the development of cancer.

Health Risks of Asphalt Emission: State-of-the-Art Advances and Research Gaps

Asphalt-related emissions pose significant health risks due to the release of volatile organic compounds (VOCs) that affect both workers in construction and the general public. Even at low concentrations, certain VOCs are highly toxic, with some of their metabolic byproducts, such as epoxides, known to cause DNA damage, oxidative stress, and other genetic alterations. The health implications are particularly concerning given that these emissions are persistent, and exposure can occur over prolonged periods, especially in urban areas where asphalt is prevalent. However, despite growing awareness, there remain significant gaps in our understanding of the long-term effects of chronic, low-level exposure to asphalt VOCs. Research to date has largely focused on acute exposure effects, particularly in occupational settings, leaving much unknown about the broader impact on the general public, especially vulnerable groups like children and the elderly. Moreover, the complex interactions between asphalt-derived VOCs and other environmental pollutants are not well understood, further complicating our understanding of their cumulative health impact. This paper provides a comprehensive overview of the current research landscape, starting with a discussion of the health risks associated with asphalt VOCs, supported by key findings from recent studies. It then explores the latest technological advancements in VOC detection, characterization, and monitoring, and identifies critical gaps in existing research.

The individual and combined effects of polycyclic aromatic hydrocarbons on asthma among US children: evidence from the NHANES study

Polycyclic Aromatic Hydrocarbons (PAHs) exposure has been linked to asthma, but their individual and combined effects in children remain unclear. Using data from the 2003-2012 National Health and Nutrition Examination Survey (NHANES), we investigated the associations between PAHs and asthma through logistic regression, Weighted Quantile Sum (WQS) regression, Quantile g Computation (qg computation), and Bayesian Kernel Machine Regression (BKMR). Subgroup analyses revealed a significant impact of PAHs on asthma, particularly in males. The WQS model showed a marginally significant combined effect of 9 PAHs on asthma (Odds Ratio = 1.37, 95% Confidence Interval: 1.06-1.75). BKMR also indicated a positive association between combined PAH exposure and asthma. 2-Hydroxyfluorene and 1-Hydroxypyrene were identified as the most significant contributors. These findings suggest that mixed PAH exposure is associated with asthma risk in children.

Transition metal-catalyzed transformations of 2-formylarylboronic acids

2-Formylarylboronic acids are easily available precursors in organic chemistry. Different types of transition metal catalysts, such as Pd(0), Pd(II), Rh(I), Ir(I), Ni(II), Cu(I), Cu(II), and Co(II), can efficiently catalyze coupling reactions of 2-formylarylboronic acids with other organic reactants. In this review, we describe the synthesis of a diverse range of carbocyclic and heterocyclic compounds, as well as acyclic compounds, via transition metal-catalyzed reactions of 2-formylarylboronic acids over the past two decades.

Comparative study of Sombor index and its various versions using regression models for top priority polycyclic aromatic hydrocarbons

The aromatic compounds having structural configurations with two or more fused benzene rings are the polycyclic aromatic hydrocarbons (PAHs). Topological indices are valuable tools for studying the structure property relationships of PAHs and also helps in predicting various properties and activities. They find applications widely in computational chemistry, drug design and QSPR studies. This article focuses on analysing the potential predictive index for Sombor index (SO), elliptic Sombor index (ESO), Euler Sombor index (EU), reverse Sombor index (RSO), reverse elliptic Sombor index (RESO) and reverse Euler Sombor index (REU) using regression models for top priority 38 PAHs. From the study it is evident that, SO and RSO have proved to be potential predictive indices among the considered degree-based and reverse degree-based indices. The variation of best predictive index with minimal RMSE are plotted for linear, quadratic and cubic regression models for better understanding.

A study on source identification of contaminated soil with total petroleum hydrocarbons (aromatic and aliphatic) in the Ahvaz oil field

The oil industry in Khuzestan province (Southwest Iran) is one of the main reasons contributing to the pollution of the environment in this area. TPH, including both aromatic and aliphatic compounds, are important parameters in creating pollution. The present study aimed to investigate the source of soil contamination by TPH in the Ahvaz oil field in 2022. The soil samples were collected from four oil centers (an oil exploitation unit, an oil desalination unit, an oil rig, and a pump oil center). An area outside the oil field was determined as a control area. Ten samples with three replicates were taken from each area according to the standard methods. Aromatic and aliphatic compounds were measured by HPLC and GC methods. The positive matrix factorization (PMF) model and isomeric ratios were used to determine the source apportionment of aromatic compounds in soil samples. The effects range low and effects range median indices were also used to assess the level of ecological risk of petroleum compounds in the soil samples. The results showed that Benzo.b.fluoranthene had the highest concentration with an average of 5667.7 ug/kg in soil samples in the Ahvaz oil field. The highest average was found in samples from the pump oil center area at 7329.48 ug/kg, while the lowest was found in control samples at 1919.4 ug/kg-1. The highest level of aliphatic components was also found in the pump oil center, with a total of 3649 (mg. Kg-1). The results of source apportionment of petroleum compounds in soil samples showed that oil activities accounted for 51.5% of the measured PAHs in soil. 38.3% of other measured compounds had anthropogenic origins, and only 10.1% of these compounds were of biotic origin. The results of the isomeric ratios also indicated the local petroleum and pyrogenic origin of PAH compounds, which is consistent with the PMF results. The analysis of ecological risk indices resulting from the release of PAHs in the environment showed that, except for fluoranthene, other PAHs in the oil exploitation unit area were above the effects range median level (ERM) and at high risk. The results of the study showed that soil pollution by total petroleum hydrocarbons (TPH), both aromatic and aliphatic, is at a high level, and is mainly caused by human activities, particularly oil activities.

The carcinogenic PAHs in breads, amount, analytical method and mitigation strategy, a systematic review study

Bread is one of the most consumed foods all over the world. Several contaminants are identified in bread. Polycyclic aromatic hydrocarbons (PAHs) is one of these contaminants. This systematic study evaluates the amount of four carcinogenic PAHs (PAH4) in various types of breads. To conduct this study, a comprehensive search was carried out using keywords of polycyclic aromatic hydrocarbons, PAHs, PAH4, and bread, with no time limitations. 17 articles were selected and fully evaluated. The observed range of PAH4 concentrations in bread varied from non-detected (ND) to 20.66 µg/kg. In the sample preparation process for analysis, an ultrasonic bath was predominantly utilized. Most chromatographic methods are able to measure PAHs in food, but the GC-MS method has been used more. To mitigate PAH levels in bread, it is suggested to incorporate antioxidants during the bread-making process. Furthermore, the type of bread, the type of fuel used to bake the bread, the temperature and the cooking time were some of the factors affecting the amount of PAH. Restricting these factors could significantly reduce PAH content. Regarding the risk assessment conducted in the manuscript, it was determined that industrial breads are usually considered safe. However, some traditional breads may pose risks in terms of their potential PAH content.

Influence of Fish Species and Wood Type on Polycyclic Aromatic Hydrocarbons Contamination in Smoked Fish Meat

Despite the numerous sensory, organoleptic and nutritional qualities, fish meat may also contain some toxic compounds with negative effects on human health. Polycyclic aromatic hydrocarbons (PAHs) are a class of chemicals resulting from incomplete combustion, found at high levels in thermally processed foods, especially in smoked fish. This research studied the influence of wood type (beech, plum and oak) and fish species (rainbow trout, carp and Siberian sturgeon) on PAH contamination in hot smoked fish. Benzo(a)Piren, Σ4PAHs and Σ15PAHs were considered as main indicators of PAH contamination. All-PAHs was quantified in all samples, indicating a specific dynamic of values due to the influence of variables. Generally, BaP (benzo(a)pyrene) content in the samples ranged from 0.11 µg/kg to 8.63 µg/kg, Σ4PAHs from 0.70 µg/kg to 45.24 µg/kg and Σ15PAHs from 17.54 µg/kg to 450.47 µg/kg. Thus, plum wood promoted the highest levels of PAHs, followed by oak and beech. Carp and Siberian sturgeon presented the highest concentrations of PAHs. Some of these parameters had levels that exceeded the limits allowed by legislation via Commission Regulation (EU) No 835/2011. Results revealed BaP levels > 2 µg/kg when plum wood was used in rainbow trout (4.04 µg/kg), carp (4.47 µg/kg) and Siberian sturgeon (8.63 µg/kg). Moreover, the same trend was found for Σ4PAHs, which exceeded 12 µg/kg in rainbow trout (17.57 µg/kg), carp (45.24 µg/kg) and Siberian sturgeon (44.97 µg/kg).

Development of a needle trap device packed with modified PAF-6-MNPs for sampling and analysis of polycyclic aromatic compounds in air

The aim of this study was to develop a new method for sampling and analyzing polycyclic aromatic hydrocarbons in the air. This was achieved by utilizing a needle trap device packed with a modified porous aromatic framework coated with magnetic nanoparticles (PAF-6-MNPs). The modified adsorbent underwent qualitative evaluation using Fourier-transform infrared spectroscopy and X-ray diffraction, as well as scanning and transmission electron microscopy. The optimal conditions for sampling polycyclic aromatic hydrocarbons compounds were determined using a dynamic atmosphere chamber. The method was validated by taking various samples from the standard chamber, and then analyzed under different environmental sampling conditions using a gas chromatography device. The limit of detection (LOD) and limit of quantification (LOQ) values for the analytes of interest, including naphthalene, anthracene, and pyrene, ranged from 0.0034-0.0051 and 0.010-0.015 μg L-1, respectively. Also, the repeatability and reproducibility of the method expressed as relative standard deviation, for the mentioned analyses were found to be in the range of 17.8-20.5% and 20-22.9%. The results indicated that over a 20 day storage period (with the needle trap device containing the analytes of interest kept in the refrigerator), there was no significant decrease in the amount of analytes compared to the initial amount. These findings suggest that, the needle trap packed with the proposed adsorbent offers a reliable, highly-sensitive, easy-to-use, and cost-effective method for sampling polycyclic aromatic hydrocarbons in the air compared to the conventional method recommended by the National Institute of Occupational Safety and Health (NIOSH), method 5515.

Understanding How Chemical Pollutants Arise and Evolve in the Brewing Supply Chain: A Scoping Review

In this study, a critical review was carried out using the Web of ScienceTM Core Collection database to analyse the scientific literature published to date to identify lines of research and future perspectives on the presence of chemical pollutants in beer brewing. Beer is one of the world's most popular drinks and the most consumed alcoholic beverage. However, a widespread challenge with potential implications for human and animal health is the presence of physical, chemical, and/or microbiological contaminants in beer. Biogenic amines, heavy metals, mycotoxins, nitrosamines, pesticides, acrylamide, phthalates, bisphenols, microplastics, and, to a lesser extent, hydrocarbons (aliphatic chlorinated and polycyclic aromatic), carbonyls, furan-derivatives, polychlorinated biphenyls, and trihalomethanes are the main chemical pollutants found during the beer brewing process. Pollution sources include raw materials, technological process steps, the brewery environment, and packaging materials. Different chemical pollutants have been found during the beer brewing process, from barley to beer. Brewing steps such as steeping, kilning, mashing, boiling, fermentation, and clarification are critical in reducing the levels of many of these pollutants. As a result, their residual levels are usually below the maximum levels allowed by international regulations. Therefore, this work was aimed at assessing how chemical pollutants appear and evolve in the brewing process, according to research developed in the last few decades.

Benzo(k)fluoranthene and benzo(b)fluoranthene degradation by Selenastrum capricornutum and identification of metabolites using HPLC-FD and HPLC-ESI-QqQ-MS/MS

Selenastrum capricornutum efficiently degrades high molecular weight polycyclic aromatic hydrocarbons (HMW PAHs). Until now, there are few studies on the benzo(k)fluoranthene (BkF) and benzo(b)fluoranthene (BbF) biodegradation by this microalga. For this reason, in the present work, extracts obtained from cultures of S. capricornutum were incubated with BkF and BbF individually, and analyzed by HPLC with fluorescence and different mass spectrometry detection modes: i) the HPLC-ESI(+)-MS/MS (MRM mode) analysis that confirmed the formation of monohydroxylated and dihydrodiol metabolites indicating that these PAHs could be simultaneously degraded through the monooxygenase and dioxygenase; ii) HPLC-ESI(+)-MS (full scan mode) that showed the formation of key metabolites containing four and two aromatic rings possibly resulting from aromatic ring-opening oxygenases, not known until now in microalgae; iii) HPLC-FD analysis that confirmed the individual BkF and BbF degradation occurring in extra- and intra-cellular extracts, indicating that an oxygenase enzyme complex is released by microalgae cells to the external environment to perform HMW PAHs biodegradation. So, this work presents new insights into the metabolic pathways of BkF and BbF biodegradation by S. capricornutum; likewise, the intra- and extra-cellular extracts of this microalgae have great potential to be applied in environmental procedures.

Polycyclic aromatic hydrocarbons in sewage-irrigated vegetables from industrial cities in Haryana, India

The majority of Indians consume a lot of vegetables because of their health advantages. High concentrations of polycyclic aromatic hydrocarbons (PAHs) in vegetables may be seriously harmful to consumers' health. The method for identifying and measuring 16 USEPA polycyclic aromatic hydrocarbons (PAHs) in samples of sewage-irrigated vegetables from three industrial cities in Haryana, India, is described in this research. Ultrasonication, liquid-liquid extraction using n-hexane as a solvent, clean-up using a Florisil column, and reversed-phase high-performance liquid chromatography with a UV detector were all included in the process. The PAHs were successfully linearized (R2 > 0.99) at various doses. Results for PAH recovery ranged from 90 to about 100%. The limit of quantification was 0.002-0.580, and the limit of detection was 0.0006-0.174 µgkg-1. Data indicated that the highest mean concentrations of ∑16 PAHs were detected in Spinach (123.36 µgkg-1), in carrot (105.09 µgkg-1), and in cucumber (63.40 µgkg-1) among leafy, underground, and fruity vegetables, respectively.

Integrated approach of nano assisted biodegradation of anthracene by Pseudomonas aeruginosa and iron oxide nanoparticles

Poly aromatic hydrocarbons (PAHs) are considered as hazardous compounds which causes serious threat to the environment dua to their more carcinogenic and mutagenic impacts. In this study, Pseudomonas aeruginosa PP4 strain and synthesized iron nanoparticles were used to evaluate the biodegradation efficiency (BE %) of residual anthracene. The BE (%) of mixed degradation system (Anthracene + PP4+ FeNPs) was obtained about 67 %. The FTIR spectra result revealed the presence of functional groups (C-H, -CH3, CC, =C-H) in the residual anthracene. The FESEM and TEM techniques were used to determine the surface analysis of the synthesized FeNPs and the average size was observed by TEM around 5-50 nm. The crystalline nature of the synthesized iron nanoparticles was confirmed by the observed different respective peaks of XRD pattern. The various functional constituents (OH, C-H, amide I, CH3) were identified in the synthesized iron nanoparticles by FTIR spectrum. In conclusion, this integrated nano-bioremediation approach could be an promising and effective way for many environmental fields like cleanup of hydrocarbon rich environment.

Environmental impact and human health effects of polycyclic aromatic hydrocarbons and remedial strategies: A detailed review

Polycyclic Aromatic Hydrocarbons (PAHs) profoundly impact public and environmental health. Gaining a comprehensive understanding of their intricate functions, exposure pathways, and potential health implications is imperative to implement remedial strategies and legislation effectively. This review seeks to explore PAH mobility, direct exposure pathways, and cutting-edge bioremediation technologies essential for combating the pervasive contamination of environments by PAHs, thereby expanding our foundational knowledge. PAHs, characterised by their toxicity and possession of two or more aromatic rings, exhibit diverse configurations. Their lipophilicity and remarkable persistence contribute to their widespread prevalence as hazardous environmental contaminants and byproducts. Primary sources of PAHs include contaminated food, water, and soil, which enter the human body through inhalation, ingestion, and dermal exposure. While short-term consequences encompass eye irritation, nausea, and vomiting, long-term exposure poses risks of kidney and liver damage, difficulty breathing, and asthma-like symptoms. Notably, cities with elevated PAH levels may witness exacerbation of bronchial asthma and chronic obstructive pulmonary disease (COPD). Bioremediation techniques utilising microorganisms emerge as a promising avenue to mitigate PAH-related health risks by facilitating the breakdown of these compounds in polluted environments. Furthermore, this review delves into the global concern of antimicrobial resistance associated with PAHs, highlighting its implications. The environmental effects and applications of genetically altered microbes in addressing this challenge warrant further exploration, emphasising the dynamic nature of ongoing research in this field.

Characteristic microbiome and synergistic mechanism by engineering agent MAB-1 to evaluate oil-contaminated soil biodegradation in different layer soil

Bioremediation is a sustainable and pollution-free technology for crude oil-contaminated soil. However, most studies are limited to the remediation of shallow crude oil-contaminated soil, while ignoring the deeper soil. Here, a high-efficiency composite microbial agent MAB-1 was provided containing Bacillus (naphthalene and pyrene), Acinetobacter (cyclohexane), and Microbacterium (xylene) to be synergism degradation of crude oil components combined with other treatments. According to the crude oil degradation rate, the up-layer (63.64%), middle-layer (50.84%), and underlying-layer (54.21%) crude oil-contaminated soil are suitable for bioaugmentation (BA), biostimulation (BS), and biostimulation+bioventing (BS+BV), respectively. Combined with GC-MS and carbon number distribution analysis, under the optimal biotreatment, the degradation rates of 2-ring and 3-ring PAHs in layers soil were about 70% and 45%, respectively, and the medium and long-chain alkanes were reduced during the remediation. More importantly, the relative abundance of bacteria associated with crude oil degradation increased in each layer after the optimal treatment, such as Microbacterium (2.10-14%), Bacillus (2.56-12.1%), and Acinetobacter (0.95-12.15%) in the up-layer soil; Rhodococcus (1.5-6.9%) in the middle-layer soil; and Pseudomonas (3-5.4%) and Rhodococcus (1.3-13.2%) in the underlying-layer soil. Our evaluation results demonstrated that crude oil removal can be accelerated by adopting appropriate bioremediation approach for different depths of soil, providing a new perspective for the remediation of actual crude oil-contaminated sites.

Effects of Polycyclic Aromatic Hydrocarbons on the Composition of the Soil Bacterial Communities in the Tidal Flat Wetlands of the Yellow River Delta of China

Polycyclic aromatic hydrocarbons (PAHs) are pervasive organic pollutants in coastal ecosystems, especially in tidal flat wetlands. However, the mechanisms through which PAHs impact the soil bacterial communities of wetlands featuring a simple vegetation structure in the Yellow River Delta (China) remain largely unclear. In this study, we examined soil samples from two sites featuring a single vegetation type (Suaeda salsa) in the Yellow River Delta. Specifically, we investigated the impacts of PAHs on the diversity and composition of soil bacteria communities through high-throughput 16 S rRNA sequencing. PAHs significantly increased the soil organic carbon content but decreased the total phosphorus content (p = 0.02). PAH contamination notably reduced soil bacterial community α diversity (Shannon index) and β diversity. Furthermore, PAHs significantly altered the relative abundance of bacterial phyla, classes, and genera (p < 0.05). Specifically, PAHs increased the relative abundance of the bacterial phyla Acidobacteriota and Gemmatimonadota (p < 0.05), while decreasing the relative abundance of Bacteroidota, Desulfobacterota, and Firmicutes compared to the control wetland (p < 0.05). Moreover, PAHs and certain soil properties [total nitrogen (TN), soil organic carbon (SOC), total phosphorus (TP), and total salt (TS)] were identified as key parameters affecting the community of soil bacteria, with the abundance of specific bacteria being both negatively and positively affected by PAHs, SOC, and TN. In summary, our findings could facilitate the identification of existing environmental problems and offer insights for improving the protection and management of tidal flat wetland ecosystems in the Yellow River Delta of China.

The Phylogeny and Metabolic Potentials of a Lignocellulosic Material-Degrading Aliiglaciecola Bacterium Isolated from Intertidal Seawater in East China Sea

Lignocellulosic materials are composed of cellulose, hemicellulose and lignin and are one of the most abundant biopolymers in marine environments. The extent of the involvement of marine microorganisms in lignin degradation and their contribution to the oceanic carbon cycle remains elusive. In this study, a novel lignin-degrading bacterial strain, LCG003, was isolated from intertidal seawater in Lu Chao Harbor, East China Sea. Phylogenetically, strain LCG003 was affiliated with the genus Aliiglaciecola within the family Alteromonadaceae. Metabolically, strain LCG003 contains various extracellular (signal-fused) glycoside hydrolase genes and carbohydrate transporter genes and can grow with various carbohydrates as the sole carbon source, including glucose, fructose, sucrose, rhamnose, maltose, stachyose and cellulose. Moreover, strain LCG003 contains many genes of amino acid and oligopeptide transporters and extracellular peptidases and can grow with peptone as the sole carbon and nitrogen source, indicating a proteolytic lifestyle. Notably, strain LCG003 contains a gene of dyp-type peroxidase and strain-specific genes involved in the degradation of 4-hydroxy-benzoate and vanillate. We further confirmed that it can decolorize aniline blue and grow with lignin as the sole carbon source. Our results indicate that the Aliiglaciecola species can depolymerize and mineralize lignocellulosic materials and potentially play an important role in the marine carbon cycle.

Applications of supramolecular assemblies in drug delivery and photodynamic therapy

One of the world's serious health challenges is cancer. Anti-cancer agents delivered to normal cells and tissues pose several problems and challenges. In this connection, photodynamic therapy (PDT) is a minimally invasive therapeutic technique used for selectively destroying malignant cells while sparing the normal tissues. Development in photosensitisers (PSs) and light sources have to be made for PDT as a first option treatment for patients. In the pursuit of developing new attractive molecules and their formulations for PDT, researchers are working on developing such type of PSs that perform better than those being currently used. For the widespread clinical utilization of PDT, effective PSs are of particular importance. Host-guest interactions based on nanographene assemblies such as functionalized hexa-cata-hexabenzocoronenes, hexa-peri-hexabenzocoronenes and coronene have attracted increasing attention owing to less complicated synthetic steps and purification processes (gel permeation chromatography) during fabrication. Noncovalent interactions provide easy and facile approaches for building supramolecular PSs and enable them to have sensitive and controllable photoactivities, which are important for maximizing photodynamic effects and minimizing side effects. Various versatile supramolecular assemblies based on cyclodextrins, cucurbiturils, calixarenes, porphyrins and pillararenes have been designed in order to make PDT an effective therapeutic technique for curing cancer and tumours. The supramolecular assemblies of porphyrins display efficient electron transfer and fluorescence for use in bioimaging and PDT. The multifunctionalization of supramolecular assemblies is used for designing biomedically active PSs, which are helpful in PDT. It is anticipated that the development of these functionalized supramolecular assemblies will provide more fascinating advances in PDT and will dramatically expand the potential and possibilities in cancer treatments.

Degradation of polycyclic aromatic hydrocarbons in aquatic environments by a symbiotic system consisting of algae and bacteria: green and sustainable technology

Polycyclic aromatic hydrocarbons (PAHs) are genotoxic, carcinogenic, and persistent in the environment and are therefore of great concern in the environmental protection field. Due to the inherent recalcitrance, persistence and nonreactivity of PAHs, they are difficult to remediate via traditional water treatment methods. In recent years, microbial remediation has been widely used as an economical and environmentally friendly degradation technology for the treatment of PAH-contaminated water. Various bacterial and microalgal strains are capable of potentially degrading or transforming PAHs through intrinsic metabolic pathways. However, their biodegradation potential is limited by the cytotoxic effects of petroleum hydrocarbons, unfavourable environmental conditions, and biometabolic limitations. To address this limitation, microbial communities, biochemical pathways, enzyme systems, gene organization, and genetic regulation related to PAH degradation have been intensively investigated. The advantages of algal-bacterial cocultivation have been explored, and the limitations of PAHs degradation by monocultures of algae or bacteria have been overcome by algal-bacterial interactions. Therefore, a new model consisting of a "microalgal-bacterial consortium" is becoming a new management strategy for the effective degradation and removal of PAHs. This review first describes PAH pollution control technologies (physical remediation, chemical remediation, bioremediation, etc.) and proposes an algal-bacterial symbiotic system for the degradation of PAHs by analysing the advantages, disadvantages, and PAH degradation performance in this system to fill existing research gaps. Additionally, an algal-bacterial system is systematically developed, and the effects of environmental conditions are explored to optimize the degradation process and improve its technical feasibility. The aim of this paper is to provide readers with an effective green and sustainable remediation technology for removing PAHs from aquatic environments.

Fabrication and characterization of manganese dioxide (MnO2) nanoparticles and its degradation potential of benzene and pyrene

MnO2 nanoparticles have a wide range of applications, including catalytic abilities due to their oxygen reduction potential. Industrial processes and the burning of organic materials released PAHs into the biosphere which have adverse effects on living organisms when continually exposed. In this study, MnO2 nanoparticles were synthesized chemically using sodium thiosulphate as reducing agent. MnO2 nanoparticles were characterized using UV-visible adsorption spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). A X-Ray Diffraction Spectrophotometer (XRD), a Scanning Electron Microscopy - Energy Dispersive X-Ray Analyzer (SEM-EDAX), and Dynamic Light Scattering (DLS) were used to identify the crystalline nature and particle size of the fabricated MnO2 nanoparticles. Batch adsorption studies were conducted to identify the optimal conditions for better benzene and pyrene adsorption from aqueous solution using MnO2 nanoparticles. They are also effective in degrading benzene and pyrene by batch adsorption as determined by their adsorption isotherms and kinetics.

Association between exposure to multiple polyaromatic hydrocarbons and periodontitis: findings from a cross-sectional study

The impact of environmental pollutant exposure on periodontitis has raised significant concerns. But the association between exposure to multiple polyaromatic hydrocarbons (PAHs) and periodontitis still remained unclear. Our study investigated the association of exposure to multiple PAHs with periodontitis. A total of 1880 participants from the National Health and Nutrition Examination Survey (NHANES) were included in this study. Urinary samples of the participants exposed to six PAHs, namely, 1-hydroxynaphthalene (1-OHN), 2-hydroxynaphthalene (2-OHN), 3-hydroxyfluorene (3-OHF), 2-hydroxyfluorene (2-OHF), 1-hydroxyphenanthrene (1-OHPhe), and 1-hydroxypyrene (1-OHPyr), were investigated. Multiple logistic regression, restricted cubic spline, and Bayesian kernel machine regression (BKMR) models were employed to identify the association between PAH exposures and periodontitis. The dose-response analysis exhibited a gradual increase in the periodontitis risk with an increase in multiple PAHs. After adjustment for several potential confounders, the odds ratio of the highest quartile (Quartile 4) was 1.648 (95% confidence interval (CI) 1.108-2.456, P = 0.014, P-t = 0.017) for 2-OHN, 2.046 (95%CI 1.352-3.104, P < 0.001, P-t = 0.005) for 3-OHF, 1.996 (95% CI 1.310-3.046, P = 0.001, P-t = 0.003) for 2-OHF, 1.789 (95% CI 1.230-2.604, P = 0.002, P-t = 0.003) for 1-OHPhe, and 1.494 (95% CI 1.025-2.181, P = 0.037, P-t = 0.021) for 1-OHPyr compared with that of the lowest quartile (Quartile 1). BKMR illustrated that the overall effect of the PAH mixture was positively related to periodontitis. Mediation analysis identified blood neutrophils as a partial mediator of 3-OHF and 2-OHF. Exposure to multiple PAHs was positively associated with periodontitis in US adults, and blood neutrophils mediate the effects of 3-OHF and 2-OHF therein.

New roles for Bacillus thuringiensis in the removal of environmental pollutants

For a long time, the well-known Gram-positive bacterium Bacillus thuringiensis (Bt) has been extensively studied and developed as a biological insecticide for Lepidoptera and Coleoptera pests due to its ability to secrete a large number of specific insecticidal proteins. In recent years, studies have found that Bt strains can also potentially biodegrade residual pollutants in the environment. Many researchers have isolated Bt strains from multiple sites polluted by exogenous compounds and characterized and identified their xenobiotic-degrading potential. Furthermore, its pathway for degradation was also investigated at molecular level, and a number of major genes/enzymes responsible for degradation have been explored. At present, a variety of xenobiotics involved in degradation in Bt have been reported, including inorganic pollutants (used in the field of heavy metal biosorption and recovery and precious metal recovery and regeneration), pesticides (chlorpyrifos, cypermethrin, 2,2-dichloropropionic acid, etc.), organic tin, petroleum and polycyclic aromatic hydrocarbons, reactive dyes (congo red, methyl orange, methyl blue, etc.), and ibuprofen, among others. In this paper, the biodegrading ability of Bt is reviewed according to the categories of related pollutants, so as to emphasize that Bt is a powerful agent for removing environmental pollutants.

Biodegradation of Benzo[a]pyrene by a White-Rot Fungus Phlebia acerina: Surfactant-Enhanced Degradation and Possible Genes Involved

Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental pollutants that pose a threat to human health. Among these PAHs, benzo[a]pyrene (BaP), a five-ring compound, exhibits high resistance to biodegradation. White-rot fungus Phlebia acerina S-LWZ20190614-6 has demonstrated higher BaP degradation capabilities compared with Phanerochaete chrysosporium and P. sordida YK-624, achieving a degradation rate of 57.7% after 32 days of incubation under a ligninolytic condition. To further enhance the biodegradation rate, three nonionic surfactants were used, and the addition of 1 or 2 g·L-1 of polyethylene glycol monododecyl ether (Brij 30) resulted in nearly complete BaP biodegradation by P. acerina S-LWZ20190614-6. Interestingly, Brij 30 did not significantly affect the activity of manganese peroxidase and lignin peroxidase, but it did decrease laccase activity. Furthermore, the impact of cytochrome P450 on BaP degradation by P. acerina S-LWZ20190614-6 was found to be relatively mild. Transcriptomic analysis provided insights into the degradation mechanism of BaP, revealing the involvement of genes related to energy production and the synthesis of active enzymes crucial for BaP degradation. The addition of Brij 30 significantly upregulated various transferase and binding protein genes in P. acerina S-LWZ20190614-6. Hence, the bioremediation potential of BaP by the white-rot fungus P. acerina S-LWZ20190614-6 holds promise and warrants further exploration.

Assessment of Colocasia esculenta leaf extract as a natural alternative for Sitophilus zeamais control: Toxicological, biochemical, and mechanistic insights

The present study assessed the toxicological, biochemical, and mechanism of action of Colocasia esculenta leaf extract (CELE) on Wistar albino rat and on cholinergic, antioxidant, and antiinflammatory enzymes in Sitophilus zeamais. This was with a view to assessing the potential benefits and safety profile of CELE as a natural alternative for insect control. The bioactivity of the fraction was evaluated using insecticidal and repellent activities against colonies of Sitophilus zeamais to obtain a VLC-chromatographed fraction which was spectroscopically characterized and investigated for enzyme inhibition. The results revealed the ethyl acetate fraction (EAF) as the most potent one with LC50 6.198 μg/ml and 6.6 ± 0.5 repellency. The EAF had an LD50 > 5000 mg/kg but repeated dose >800 mg/kgbw po administration caused significant (p < 0.05) increase in liver and kidney function biomarkers accompanied with elevated atherogenic and coronary indices. Also, renal and hepatomorphological lesions increased in a dose-dependent manner. The High-Performance Liquid Chromatography analysis profiled 7 unknown compounds while the GC-qMS revealed 103 compounds in the CC6 fraction allowing for their identification, quantification, and providing insights into the biological activities and its potentials application. The CC6 fraction inhibited glutathione S-transferase (IC50 = 2265.260.60 mg/ml), superoxide dismutase (IC50 = 1485.300.78 mg/ml), catalase (IC50 = 574.471.57 mg/ml), acetyl cholinesterase (IC50 = 838.280.51 mg/ml), butyryl cholinesterase (IC50 = 1641.76 ± 1.14 mg/ml) and upregulated cyclooxygenase-2 (IC50 = 37.89 ± 0.15 mg/ml). Based on the result of the study, it could be inferred that the unidentified compounds present in the EAF exhibit strong insecticidal properties. The study concluded that the acute toxicity of the potent fraction showed no abnormal clinical toxic symptoms while a repeated dose of the extract in sub-acute studies showed a toxic effect that is dose-dependent. The mechanism of action of the purified fraction could be said to be by inhibition of cholinergic and antioxidant enzymes. However, the potent fraction also upregulated the activity of anti-inflammatory enzymes. Hence, regulated amount of CELE at a repeated dose <800 mg/kgbw could be considered for use as an anti-pest agent in Integrated Pest Management of Sitophilus zeamais.

Benzo[b]fluoranthene induces male reproductive toxicity and apoptosis via Akt-Mdm2-p53 signaling axis in mouse Leydig cells: Integrating computational toxicology and experimental approaches

This study aims to explore the male reproductive toxicity of Benzo[b]fluoranthene (BbF) and related mechanisms. The results of computational toxicology analysis indicated male reproductive toxicity of BbF was related to apoptosis of Leydig cells and that Akt/p53 pathway might play a key role. In experiments, BbF induced testosterone decline, decreased concentration and motility of sperm and aggravated testicular pathological injury in mice. Besides, BbF led to apoptosis in Leydig cells, and decreased expressions of p-Akt and Bcl2, while improving the expressions of p53, Bax and Cleaved Caspase-3 in vivo and in vitro. Further, compared with BbF group, Akt activator SC79 significantly reduced cell apoptosis rate, improved cell viability, promoted the expressions of p-Akt and p-Mdm2, and reversed the above molecular expressions. Similarly, p53 inhibitor Pifithrin-α also significantly enhanced the cell vitality, alleviated the apoptosis of TM3 cells induced by BbF, and decreased the expressions of Bax and Cleaved Caspase-3, with the up-regulation of Bcl2. To sum up, by inhibiting Akt-Mdm2 signaling, BbF activated the p53-mediated mitochondrial apoptosis pathway, further inducing the apoptosis of Leydig cells, therefore resulting in testosterone decline and male reproductive damage. Besides, this study provided a valid mode integrating computational toxicology and experimental approaches in toxicity testing.

A review on structural mechanisms of protein-persistent organic pollutant (POP) interactions

With the advent of the industrial revolution, the accumulation of persistent organic pollutants (POPs) in the environment has become ubiquitous. POPs are halogen-containing organic molecules that accumulate, and remain in the environment for a long time, thus causing toxic effects in living organisms. POPs exhibit a high affinity towards biological macromolecules such as nucleic acids, proteins and lipids, causing genotoxicity and impairment of homeostasis in living organisms. Proteins are essential members of the biological assembly, as they stipulate all necessary processes for the survival of an organism. Owing to their stereochemical features, POPs and their metabolites form energetically favourable complexes with proteins, as supported by biological and dose-dependent toxicological studies. Although individual studies have reported the biological aspects of protein-POP interactions, no comprehensive study summarizing the structural mechanisms, thermodynamics and kinetics of protein-POP complexes is available. The current review identifies and classifies protein-POP interaction according to the structural and functional basis of proteins into five major protein targets, including digestive and other enzymes, serum proteins, transcription factors, transporters, and G-protein coupled receptors. Further, analysis detailing the molecular interactions and structural mechanism evidenced that H-bonds, van der Waals, and hydrophobic interactions essentially mediate the formation of protein-POP complexes. Moreover, interaction of POPs alters the protein conformation through kinetic and thermodynamic processes like competitive inhibition and allostery to modulate the cellular signalling processes, resulting in various pathological conditions such as cancers and inflammations. In summary, the review provides a comprehensive insight into the critical structural/molecular aspects of protein-POP interactions.

Optimization and Comparison of Microwave-Assisted Extraction, Supercritical Fluid Extraction, and Eucalyptus Oil-Assisted Extraction of Polycyclic Aromatic Hydrocarbons from Soil and Sediment

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic compounds of major concern that mainly accumulate in soils and sediments, and their extraction from environmental matrices remains a crucial step when determining the extent of contamination in soils and sediments. The objective of the present study was to compare the extraction of PAHs (phenanthrene, pyrene, chrysene, and benzo[a]pyrene) from spiked soil and sediment using supercritical fluid extraction (SFE) with ethanol as the modifier, microwave-assisted extraction (MAE), and eucalyptus oil-assisted extraction (EuAE). Recoveries of PAHs were comparable between the three methods, and >80% of applied pyrene, chrysene and benzo[a]pyrene were recovered. The most efficient method of extracting PAHs from naturally incurred soils with different levels of contamination was SFE. A longer extraction time was required for the EuAE method compared with SFE and MAE under optimized conditions. However, EuAE required lower extraction temperatures (15-20 °C) compared with SFE (80 °C) and MAE (110-120 °C), and consumed less solvent than SFE and MAE. Compared with hexane/acetone used in MAE, the use of ethanol in SFE and eucalyptus oil in EuAE can be considered as more sustainable approaches to efficiently extract PAHs from spiked/naturally contaminated soils and sediments. And, although less efficient for matrices containing higher carbon content, EuAE offered a cheap, low-tech approach to extracting PAHs. Environ Toxicol Chem 2023;42:982-994. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Recent Progress in Cyclic Aryliodonium Chemistry: Syntheses and Applications

Hypervalent aryliodoumiums are intensively investigated as arylating agents. They are excellent surrogates to aryl halides, and moreover they exhibit better reactivity, which allows the corresponding arylation reactions to be performed under mild conditions. In the past decades, acyclic aryliodoniums are widely explored as arylation agents. However, the unmet need for acyclic aryliodoniums is the improvement of their notoriously low reaction economy because the coproduced aryl iodides during the arylation are often wasted. Cyclic aryliodoniums have their intrinsic advantage in terms of reaction economy, and they have started to receive considerable attention due to their valuable synthetic applications to initiate cascade reactions, which can enable the construction of complex structures, including polycycles with potential pharmaceutical and functional properties. Here, we are summarizing the recent advances made in the research field of cyclic aryliodoniums, including the nascent design of aryliodonium species and their synthetic applications. First, the general preparation of typical diphenyl iodoniums is described, followed by the construction of heterocyclic iodoniums and monoaryl iodoniums. Then, the initiated arylations coupled with subsequent domino reactions are summarized to construct polycycles. Meanwhile, the advances in cyclic aryliodoniums for building biaryls including axial atropisomers are discussed in a systematic manner. Finally, a very recent advance of cyclic aryliodoniums employed as halogen-bonding organocatalysts is described.

Identification of New Dioxygenases Able to Recognize Polycyclic Aromatic Hydrocarbons with High Aromaticity

Polycyclic aromatic hydrocarbons (PAHs), products from the incomplete combustion of crude oil, are pollutants present in nature. Ring hydroxylating dioxygenase enzymes are able to catalyze polycyclic aromatic hydrocarbons in the biodegradation process with a high degree of stereo-, regio-, and enantiospecificity. In this work, we present the first approximation of the binding modes of 9 PAHs with high aromaticity in the catalytic sites of biphenyl or naphthalene dioxygenases from four microorganisms usually used in bio-remediation processes: Sphingobium yanoikuyae, Rhodococcus jostii RHA1, Pseudomonas sp. C18, and Paraburkholderia xenovorans. Molecular modeling studies of two biphenyl dioxygenases from Sphingobium yanoikuyae and Paraburkholderia xenovorans showed good binding affinity for PAHs with 2–4 benzene rings (fluoranthene, pyrene, and chrysene), and both enzymes had a similar amount of substrate binding. Molecular docking studies using naphthalene dioxygenase from Pseudomonas sp. C18 showed that the enzyme is able to accommodate PAHs with high aromaticity (benzo(a)pyrene, indeno(1,2,3-cd)pyrene), with good docking scores. This study provides important insight into the utility of naphthalene dioxygenases in the degradation of HAPs with high aromaticity.

Formation and growth mechanisms of polycyclic aromatic hydrocarbons: A mini-review

Polycyclic aromatic hydrocarbons (PAHs) are mostly formed during the incomplete combustion of organic materials, but their importance and presence in materials science, and astrochemistry has also been proven. These carcinogenic persistent organic pollutants are essential in the formation of combustion generated particles as well. Due to their significant impact on the environment and human health, to understand the formation and growth of PAHs is essential. Therefore, the most important growth mechanisms are reviewed, and presented here from the past four decades (1981-2021) to initiate discussions from a new perspective. Although, the collected and analyzed observations are derived from both experimental, and computational studies, it is neither a systematic nor a comprehensive review. Nevertheless, the mechanisms were divided into three main categories, acetylene additions (e.g. HACA), vinylacetylene additions (HAVA), and radical reactions, and discussed accordingly.

Fate of PAHs in treated wastewater reused as irrigation water: Environmental risks in water-soil-ryegrass multimedia system

The main aim of this study was to determine the fate, bio-metabolism and environmental risk of low-ring and high-ring polycyclic aromatic hydrocarbons (PAHs) in a water-soil-ryegrass multi-media system, under long-term irrigation condition with micro-polluted treated wastewater. Field experiments were carried out to simulate garden irrigation using treated wastewater containing typical representative low-ring naphthalene (Nap) and high-ring benzo[a]pyrene (BaP). The results showed that BaP's vertical attenuation rate and adsorption accumulation rate were 1.7 and 1.2 times higher than Nap's, respectively. The adsorption, biodegradation, and the rhizosphere effect were responsible for 40.7%, 28.4%, 21.6%, and 30.5%, 36.6%, 17.7%, respectively, of the attenuation of BaP and Nap. The major metabolic pathways of Nap and BaP are hydroxylation, ring opening cleavage, and decarboxylation, with the metabolic chain of BaP being longer than that of Nap due to more ring cleaving reactions. Pseudomonas, Mycobacterium, and Sphingomonas were the functional microorganisms with PAHs degradation capacity that were positively correlated with PAHs degradation, particularly in the rhizosphere. After ten years of irrigation with treated wastewater, the prediction of environmental risk revealed that there were few potential risks. Thus, the results of this feasibility study demonstrated that using treated wastewater for garden irrigation was a relatively safe and effective strategy.

Occurrence, fate, and toxicity of emerging contaminants in a diverse ecosystem

Activities that were developed for better/modern living conditions of humans are the primary source of contaminants to the natural ecosystem. Some of the compounds involved in urbanization and industrialization are termed emerging contaminants (ECs) or contaminants of emerging concern. ECs are either chemical or derived from natural sources which environmental concerns and public health have been raised in recent years. ECs enter wastewater treatment systems and migrate from here to different ecosystems as direct or by-products. They are persistent and also stay for a long duration due to their less biodegradation and photodegradation nature. Also, ECs accumulated in living cells and transformed through trophic levels. Technological developments and their application/utility in daily life led to the production of various components that are being added to the natural ecosystem. The treated/untreated wastewater enters into fresh/marine water bodies and gets accumulated into fauna, flora, and sediments. These pollutants/contaminants that are getting added on an everyday basis bring about changes in the existing ecosystem balances. ECs have been found in almost every country’s natural environment, and as a result, they became a global issue. The present review discusses the route and transport of selected ECs into the terrestrial ecosystem through water and other means and how they influence the natural process in an ecosystem. The ECs such as personal care products, pharmaceuticals, polyaromatic hydrocarbons, endocrine disruptors, nanoparticles, and microplastics are highlighted in this review.

Circulating microRNAs as biomarkers of environmental exposure to polycyclic aromatic hydrocarbons: potential and prospects

Exposure to polycyclic aromatic hydrocarbons (PAHs) produced from various pyrogenic and petrogenic sources in the environment has been linked to a variety of toxic effects in the human body. Genome-wide analyses have shown that microRNAs (miRNAs) can function as novel and minimally invasive biomarkers of environmental exposure to PAHs. The objective of this study is to explore miRNA signatures associated with early health effects in response to chronic environmental exposure to PAHs. We systematically searched Scopus and PubMed databases for studies related to exposure of PAHs with changes in miRNA expression patterns that represent early health effects in the exposed population. Based on previous studies, we included 15 cell-based and 9 each of animal model and human population-based studies for assessment. A total of 11 differentially expressed PAH-responsive miRNAs were observed each in two or more cell-based studies (miR-181a and miR-30c-1), animal model studies (miR-291a and miR-292), and human population-based studies (miR-126, miR-142-5p, miR-150-5p, miR-24-3p, miR-27a-3p, miR-28-5p, and miR-320b). In addition, miRNAs belonging to family miR-122, miR-199, miR-203, miR-21, miR-26, miR-29, and miR-92 were found to be PAH-responsive in both animal model and cell-based studies; let-7, miR-126, miR-146, miR-30, and miR-320 in both cell-based and human population-based studies; and miR-142, miR-150, and miR-27 were found differentially expressed in both animal model and human population-based studies. The only miRNA whose expression was found to be altered in all the three groups of studies is miR-34c. Association of environmental exposure to PAHs with altered expression of specific miRNAs indicates that selective miRNAs can be used as early warning biomarkers in PAH-exposed population.