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1.
J Environ Sci (China) ; 124: 782-793, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182183

RESUMO

Nitrated polycyclic aromatic hydrocarbons (NPAHs) are widespread organic pollutants that possess carcinogenic and mutagenic properties, so they may pose a risk to the environment and human health. In this study, the concentrations of 15 NPAHs and 16 polycyclic aromatic hydrocarbons (PAHs) in 30 surface water samples and 26 sediment samples were measured in 2018 from the Taige Canal, one of the main rivers flowing into Taihu Lake, China. The total NPAH concentrations in water and sediment ranged from 14.7 to 235 ng/L and 22.9 to 96.5 ng/g dw, respectively. 9-nitrophenanthrene (nd-76.3 ng/L) was the dominant compound in surface water, while 2+3-nitrofluoranthene (1.73-18.1 ng/g dw) dominated in sediment. Among PAHs, concentration ranging from 1,097 to 2,981 ng/L and 1,089 to 4,489 ng/g dw in surface water and sediment, respectively. There was a strong positive correlation between the log octanol-water partition coefficient (Kow) and log sediment-water partition coefficient due to hydrophobic interaction. The fugacity fraction value increased with the decrease of log Kow, and chrysene was transferred from water into sediment. The residual NPAHs in surface water and sediment of the Taige Canal have partial correlation. Diesel engine and coal combustion emissions were probably the principal sources of NPAHs in surface water and sediment. The results of ecological risk assessment showed that some NPAHs in water (e.g, 1-nitropyrene and 6-nitrochrysene) and sediment (e.g., 2-nitrobiphenyl, 5-nitroacenaphthene, 9-nitrophenanthrene and 2+3-nitrofluoranthene) had moderate ecological risks, which should be of concern.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , China , Crisenos/análise , Carvão Mineral/análise , Monitoramento Ambiental/métodos , Fluorenos , Sedimentos Geológicos/química , Humanos , Nitratos , Octanóis , Fenantrenos , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Água , Poluentes Químicos da Água/análise
2.
Environ Pollut ; 312: 120070, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36058316

RESUMO

Vehicle emissions are an important source of nitrated aromatic compounds (NACs) in particulate size smaller 2.5 µm (PM2.5), which adversely affect human health and biodiversity, especially in urban areas. In this study, filter-based PM2.5 samples were collected during October 14-19, 2019, in a busy urban tunnel (approximately 35,000 vehicles per day) in south China to identify PM2.5-bound NACs. Among them, 2,8-dinitrodibenzothiophene, 3-nitrodibenzofuran and 2-nitrodibenzothiophene were the most abundant nitrated polycyclic aromatic hydrocarbons (NPAHs), while 2-methyl-4-nitrophenol, 2,4-dinitrophenol, 3-methyl-4-nitrophenol and 4-nitrophenol were the most abundant nitrophenols (NPs). The observed mean fleet emission factors (EFs) of NPAHs and NPs were 2.2 ± 2.1 and 7.7 ± 4.1 µg km-1, and were 2.9 ± 2.7 and 10.2 ± 5.4 µg km-1 if excluding electric and liquefied petroleum gas vehicles, respectively. Regression analysis revealed that diesel vehicles (DVs) had NPAH-EFs (55.3 ± 5.3 µg km-1) approximately 180 times higher than gasoline vehicles (GVs) (0.3 ± 0.2 µg km-1), and NP-EFs (120.6 ± 25.8 µg km-1) approximately 30 times higher than GVs (4.1 ± 0.2 µg km-1), and thus 89% NPAH emissions and 56% NP emissions from the onroad fleets were contributed by DVs although DVs only accounted for 3.3% in the fleets. Methanol solution-based light absorption measurements demonstrated that the mean incremental light absorption for methanol-soluble brown carbon at 365 nm was 6.8 ± 2.2 Mm-1, of which the 44 detected NACs only contributed about 1%. The mean EF of the 7 toxic NACs was approximately 3% that of the 16 priority PAHs; However, their benzo(a)pyrene toxic equivalence quotients (TEQBaP) could reach over 25% that of the PAHs. Moreover, 6-nitrochrysene mainly from DVs contributed 93% of the total TEQBaP of the NACs. This study demonstrated that enhancing DV emission control in urban areas could benefit the reduction of exposure to air toxins such as 6-nitrochrysene.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , 2,4-Dinitrofenol , Poluentes Atmosféricos/análise , Benzo(a)pireno/análise , Carbono/análise , Crisenos , Monitoramento Ambiental , Gasolina/análise , Humanos , Metanol/análise , Nitratos/análise , Nitrocompostos/análise , Nitrofenóis , Material Particulado/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Emissões de Veículos/análise
3.
Mar Pollut Bull ; 183: 114073, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36084609

RESUMO

In this study, we examined the distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Mahanadi River Estuary (MRE), identified sources, and evaluated the ecological toxicity. The PAHs distributions in MRE ranged from 13.1 to 685.4 ng g-1 (dry weight), with a mean value of 192.91 ± 177.56 ng g-1 (dry weight). Sediments at sites S11, S8, and S13 have the highest 3-rings, 4-rings, and 5-rings PAHs, respectively. In MRE, pyrene has a significantly higher concentration with a mean value of 30.51 ng g-1, followed by Fluoranthene (86.2 ng g-1), Chrysene (67.4 ng g-1), and Benzo(k)fluoranthene (54.2 ng g-1). Site S8 had a higher total PAH concentration than sites S11, S13, and S1. The diagnostic and principal component analysis suggests that PAHs originated from petroleum, oil, biomass, and coal combustion. Higher toxic and mutagenic equivalent quotients indicate potential aquatic toxicity and a need for continuous monitoring of MRE for PAHs pollution.


Assuntos
Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , China , Crisenos/análise , Carvão Mineral/análise , Monitoramento Ambiental , Estuários , Sedimentos Geológicos/química , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Pirenos/análise , Medição de Risco , Rios/química , Poluentes Químicos da Água/análise
4.
J Chromatogr A ; 1681: 463425, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36054993

RESUMO

In this work, deep eutectic solvents-based carbon dots (DESCDs) were prepared and bonded to the silica surface for the first time to form a new hydrophobic chromatographic stationary phase (Sil-DESCDs). The successful preparation of DESCDs and Sil-DESCDs were demonstrated by a series of characterizations including transmission electron microscopies, laser scanning confocal microscope, Fourier transform infrared spectrometry, elemental analysis, etc. Retention behavior of Sil-DESCDs was evaluated using Tanaka and Engelhardt standard test mixtures. The results showed that this new stationary phase had excellent separation performance for polycyclic aromatic hydrocarbons, flavonoids, aromatic amines and phenolic compounds. Excellent separation selectivity for the 3-phenylene ring isomers including phenanthrene and anthracene, the 4-phenylene ring isomers including pyrene, triphenylene, chrysene and 1,2-benzanthracene was also obtained. Especially, prednisolone and hydrocortisone, which have very similar structures, can be separated using pure water as the mobile phase. In addition, the flavonoids in Astragalus extracts including calycosin-7-glucoside, ononin, calycosin and formononetin were determined using this new column, their concentrations were 0.050, 0.031, 0.023 and 0.034 mg/mL, respectively.


Assuntos
Cromatografia de Fase Reversa , Hidrocarbonetos Policíclicos Aromáticos , Aminas , Antracenos , Carbono , Cromatografia Líquida de Alta Pressão/métodos , Crisenos , Solventes Eutéticos Profundos , Flavonoides/análise , Glucosídeos , Hidrocortisona , Interações Hidrofóbicas e Hidrofílicas , Hidrocarbonetos Policíclicos Aromáticos/análise , Prednisolona , Pirenos , Dióxido de Silício/química , Água
5.
Sci Total Environ ; 848: 157246, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-35908714

RESUMO

Most previous water quality studies oversimplified in-stream processes for modeling the fate and transport of critical organic contaminants, such as Polycyclic Aromatic Hydrocarbons (PAHs). Taking four selected PAHs as representative organic contaminants, we developed a numerical modeling framework using a Water Quality Analysis Simulation Program 8 (WASP8) and a well-established watershed model, i.e., Soil and Water Assessment Tool (SWAT) to: (1) address the influence of in-stream processes, including direct photolysis, volatilization, partitioning of PAHs to suspended solids, and DOC complexation processes on PAH concentrations; and (2) establish relationships between spatiotemporal distribution of environmental factors (e.g., ice coverage, water temperature, wind, and light attenuation), in-stream processes, and PAH concentrations at a watershed scale. Using calibrated SWAT and WASP8 models, we evaluated the impacts of seasonal changes in environmental factors on in-stream processes in the Muskeg River watershed, which is part of the Athabasca Oil Sands Region (AOSR), the third-largest crude oil reserves of the world in western Canada. Among four selected PAHs, simulation results suggest that Naphthalene primarily decay in the water through volatilization or direct photolysis. For Phenanthrene, Pyrene, and Chrysene, DOC complexation, volatilization, and direct photolysis all contribute to their decay in the water, with a strong dependence on seasonality. Model simulations indicated that direct photolysis and volatilization rates are meager in cold seasons, mainly due to low river temperature and ice coverage. However, these processes gradually resume when entering the warm season. In summary, the model simulation results suggest that critical in-stream processes such as direct photolysis, volatilization, and partitioning and their relationship with environmental factors should be considered when simulating the fate and transport of organic contaminants in the river systems. Our results also reveal that the relationship between environmental factors and fate processes affecting PAH concentrations can vary across a watershed and in different seasons.


Assuntos
Petróleo , Fenantrenos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Alberta , Crisenos/análise , Monitoramento Ambiental/métodos , Gelo/análise , Naftalenos/análise , Campos de Petróleo e Gás , Petróleo/análise , Fenantrenos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Pirenos/análise , Rios , Solo , Poluentes Químicos da Água/análise
6.
J Hazard Mater ; 436: 129161, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35739702

RESUMO

The effects of microplastics and sorbed polycyclic aromatic hydrocarbons at community levels were rarely assessed in laboratory experiments, despite their obvious advantage in reflecting better the natural conditions compared to traditionally single species-focused toxicological experiments. In the current study, the multifaceted effects of polyvinyl chloride and chrysene, acting alone or combined, on general marine meiobenthos, but with a special focus on free-living marine nematode communities were tested in a laboratory experiment carried in microcosms. The meiobenthos was exposed to two polyvinyl chloride (5 and 10 mg.kg-1 Dry Weight 'DW') and chrysene (37.5 and 75 ng.g-1 DW) concentrations, respectively, as well as to a mixture of both compounds, for 30 days. The results highlighted a significant decrease in the abundance of all meiobenthic generic groups, including nematodes, directly with increasing dosages of these compounds when added alone. The addition of chrysene adheres to microplastics, making the sediment matrix glueyer, hence inducing greater mortality among generic meiobenthic groups. Moreover, the nematofauna went through a strong restructuring phase following the exposure to both compounds when added alone, leading to the disappearance of sensitive nematodes and their replacement with tolerant taxa. However, the similarity in nematofauna composition between control and polyvinyl chloride and chrysene mixtures suggests that the toxicity of the latter could be attenuated by its physical bonding to the former pollutant. Other changes in the functional traits within the nematode communities were a decline in the fertility of females and an increase of the pharyngeal pumping power following exposure to both pollutants for the dominant species. The latter results were also supported by additional toxicokinetics analyses and in silico modeling.


Assuntos
Microplásticos , Nematoides , Animais , Crisenos/farmacologia , Plásticos , Cloreto de Polivinila/toxicidade
7.
Food Res Int ; 157: 111366, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35761626

RESUMO

More than 5.8 million tonnes of oil have been spilled into the oceans. Some oil disasters marked history, causing multiple social and economic consequences in addition to catastrophic environmental impacts. Recently, Brazil and Mauritius faced oil disasters that have severely impacted seafood sanitary credibility. One of the components of the oil composition are the polycyclic aromatic hydrocarbons (PAH), which are the main contamination markers of petrogenic origin. There is enough evidence to correlate the intake of food contaminated with PAH with increased risks of developing cancer. The set PAH4, composed of benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, and chrysene, and the set PAH8, composed of benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[ghi]perylene, chrysene, dibenzo[a,h]anthracene, and indeno[1,2,3-cd]pyrene are recognized as markers of food chemical contamination. After oil disasters in the oceans, the risk to the health of seafood consumers tends to be of special concern, Countries like the European Union set maximum levels for benzo[a]pyrene (5 µg kg-1) and PAH4 (30 µg kg-1) in bivalve mollusks. Levels of concern established by countries that have faced oil disasters are given special attention in this review. Laboratory analysis of PAH in food samples is very challenging because it deals with quite different kinds of matrices. Furthermore, analytical results are usually related to the closure or reopening of cultivated areas and fishing points. Therefore, the progress of the analytical methods for PAH in seafood is covered in detail. Chemical laboratory measurements provide essential data to assess the potential risks to human health due to consumption of seafood contaminated with PAH. The main human health risk assessment approaches in a seafood contamination scenario with PAH are reviewed and discussed, providing an insightful and guiding tool to each step of the risk assessment framework.


Assuntos
Desastres , Poluição por Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Antracenos/análise , Benzo(a)pireno , Crisenos/análise , Inocuidade dos Alimentos , Humanos , Poluição por Petróleo/efeitos adversos , Poluição por Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise
8.
Carcinogenesis ; 43(8): 746-753, 2022 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-35749296

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are recognized as potential etiological agents in the development of oral cancer in smokers. In particular, benzo[a]pyrene (B[a]P) and dibenzo[def,p]chrysene (DB[a,l]P) are detected in cigarette smoke and the environment and can induce DNA damage, mutagenesis and carcinogenesis in the oral cavity of rodents. Consequently, DNA adducts are regarded as the most direct markers of genotoxicity and can be used as biomarkers of cancer risk. Thus, this study used LC-MS/MS analysis with isotope labeled internal standard to detect and quantify DNA adducts derived from B[a]P and DB[a,l]P in buccal cells of cigarette smokers and non-smokers. Participants in this study include 21 smokers and 16 non-smokers. Our data are the first to report that levels (mean ± SD) of BPDE-N2-dG were significantly (P < 0.001) higher in smokers (20.18 ± 8.40 adducts/108 dG) than in non-smokers (0.84 ± 1.02 adducts/108 dG). Likewise, levels of DBPDE-N6-dA in smokers (5.49 ± 3.41 adducts/108 dA) were significantly higher (P = 0.019) than non-smokers (2.76 ± 2.29 adducts/108 dA). Collectively, the results of this clinical study support that PAHs in tobacco smoke can contribute to the development of oral cancer in humans.


Assuntos
Neoplasias Bucais , Hidrocarbonetos Policíclicos Aromáticos , Produtos do Tabaco , Poluição por Fumaça de Tabaco , Benzo(a)pireno/toxicidade , Carcinógenos/análise , Carcinógenos/toxicidade , Cromatografia Líquida , Crisenos/análise , Adutos de DNA , Humanos , Mucosa Bucal , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/genética , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Espectrometria de Massas em Tandem , Tabaco/efeitos adversos , Produtos do Tabaco/toxicidade
9.
Artigo em Inglês | MEDLINE | ID: mdl-35410049

RESUMO

The principal aim of the present study was to develop and apply novel ex vivo tests as an alternative to cell cultures able to evaluate the possible effects of emerging and legacy contaminants in Caretta caretta. To this end, we performed ex vivo experiments on non-invasively collected whole-blood and skin-biopsy slices treated with chrysene, MEHP, or PBDE-47. Blood samples were tested by oxidative stress (TAS), immune system (respiratory burst, lysozyme, and complement system), and genotoxicity (ENA assay) biomarkers, and genotoxic and immune system effects were observed. Skin slices were analyzed by applying a 2D-PAGE/MS proteomic approach, and specific contaminant signatures were delineated on the skin proteomic profile. These reflect biochemical effects induced by each treatment and allowed to identify glutathione S-transferase P, peptidyl-prolyl cis-trans isomerase A, mimecan, and protein S100-A6 as potential biomarkers of the health-threatening impact the texted toxicants have on C. caretta. Obtained results confirm the suitability of the ex vivo system and indicate the potential risk the loggerhead sea turtle is undergoing in the natural environment. In conclusion, this work proved the relevance that the applied ex vivo models may have in testing the toxicity of other compounds and mixtures and in biomarker discovery.


Assuntos
Tartarugas , Animais , Biomarcadores/metabolismo , Crisenos , Dietilexilftalato/análogos & derivados , Éteres Difenil Halogenados , Proteômica , Tartarugas/metabolismo
10.
J Org Chem ; 87(2): 1559-1563, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-35014253

RESUMO

We have developed robust, operationally simple syntheses of fluorenes and of dibenzo[g,p]chrysenes through oxidative cascade processes. These structures that are commonly encountered in optoelectronic materials, dyes, and pharmaceutical products are accessible from 1,4-dioxaspiro[4.5]decan-8-one. The reactions are conducted open to air with inexpensive, safe CuBr2 or CuCl2.


Assuntos
Crisenos , Fluorenos , Oxirredução , Estresse Oxidativo
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 270: 120817, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35030417

RESUMO

In this article, Density Functional Theory based calculations, including dispersion corrections, PBE0(D3BJ)/Def2-TZVP(-f), were performed to elucidate the photophysics of the [Ru(bpy)2(HAT)]2+ complex in water. In addition, the thermodynamics of the charge and electron transfer excited state reactions of this complex with oxygen, nitric oxide and Guanosine-5'-monophosphate nucleotide (GMP) were investigated. The first singlet excite state, S1, strongly couples with the second and third triplet excited states (T2 and T3) giving rise to a high intersystem crossing rate of 6.26 × 1011 s-1 which is ∼106 greater than the fluorescence rate decay. The thermodynamics of the excited reactions revealed that all electron transfer reactions investigated are highly favorable, due mainly to the high stability of the triply charged radical cation 2PS•3+ species formed after the electron has been transferred. Excited state electron transfer from the GMP nucleotide to the complex is also highly favorable (ΔGsol = -92.6 kcal/mol), showing that this complex can be involved in the photooxidation of DNA, in line with experimental findings. Therefore, the calculations allow to conclude that the [Ru(bpy)2(HAT)]2+ complex can act in Photodynamic therapy through both mechanisms type I and II, through electron transfer from and to the complex and triplet-triplet energy transfer, generating ROS, RNOS and through DNA photooxidation. In addition, the work also opens a perspective of using this complex for the in-situ generation of the singlet nitroxyl (1NO-) species, which can have important applications for the generation of HNO and may have, therefore, important impact for physiological studies involving HNO.


Assuntos
Compostos Organometálicos , Rutênio , 2,2'-Dipiridil , Compostos Aza , Crisenos , Elétrons
12.
Toxicol Appl Pharmacol ; 438: 115830, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-34933053

RESUMO

Dibenzo[def,p]chrysene (DBC) is an environmental polycyclic aromatic hydrocarbon (PAH) that causes tumors in mice and has been classified as a probable human carcinogen by the International Agency for Research on Cancer. Animal toxicity studies often utilize higher doses than are found in relevant human exposures. Additionally, like many PAHs, DBC requires metabolic bioactivation to form the ultimate toxicant, and species differences in DBC and DBC metabolite metabolism have been observed. To understand the implications of dose and species differences, a physiologically based pharmacokinetic model (PBPK) for DBC and major metabolites was developed in mice and humans. Metabolism parameters used in the model were obtained from experimental in vitro metabolism assays using mice and human hepatic microsomes. PBPK model simulations were evaluated against mice dosed with 15 mg/kg DBC by oral gavage and human volunteers orally microdosed with 29 ng of DBC. DBC and its primary metabolite DBC-11,12-diol were measured in blood of mice and humans, while in urine, the majority of DBC metabolites were obeserved as conjugated DBC-11,12-diol, conjugated DBC tetrols, and unconjugated DBC tetrols. The PBPK model was able to predict the time course concentrations of DBC, DBC-11,12-diol, and other DBC metabolites in blood and urine of human volunteers and mice with reasonable accuracy. Agreement between model simulations and measured pharmacokinetic data in mice and human studies demonstrate the success and versatility of our model for interspecies extrapolation and applicability for different doses. Furthermore, our simulations show that internal dose metrics used for risk assessment do not necessarily scale allometrically, and that PBPK modeling provides a reliable approach to appropriately account for interspecies differences in metabolism and physiology.


Assuntos
Crisenos/administração & dosagem , Crisenos/farmacocinética , Cistina/análogos & derivados , Animais , Carcinógenos/administração & dosagem , Carcinógenos/farmacocinética , Cistina/administração & dosagem , Cistina/farmacocinética , Feminino , Humanos , Masculino , Camundongos , Modelos Biológicos , Neoplasias/induzido quimicamente
13.
Water Sci Technol ; 84(10-11): 2737-2748, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34850690

RESUMO

Polyaromatic hydrocarbons (PAHs) are uncharged, non-polar molecules generated from natural and anthropogenic activities, where the emissions from anthropogenic activities predominate. Chrysene is a high molecular weight PAH, which is found to be highly recalcitrant and mutagenic in nature. The aim of this study was to isolate chrysene-degrading microorganisms from oil-contaminated water and to enhance their degradative conditions using design expert. From the various samples collected, 19 bacterial strains were obtained through enrichment culture and the one which showed highest activity was identified by 16S rRNA sequencing as Bacillus halotolerans. Under optimum conditions of 100 mg/L chrysene concentration, 1,000 mg/L nitrogen source, and pH 6, B. halotolerans exhibited 90% chrysene degradation on sixth day. Positive results for the enzymes laccase and catechol 1,2 dioxygenase confirmed the ability for chrysene degradation by the isolated strain. Major metabolic intermediate determined in gas chromatography-mass spectrometry (GCMS) analysis was diisooctyl phthalate. Hence it can be concluded that B. halotolerans can be a promising candidate for the removal of high molecular weight (HMW) hydrocarbons from contaminated environments.


Assuntos
Crisenos , Hidrocarbonetos Policíclicos Aromáticos , Bactérias/genética , Biodegradação Ambiental , RNA Ribossômico 16S/genética , Água
14.
J Phys Chem Lett ; 12(39): 9493-9500, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34559534

RESUMO

Multiphoton excitation promises opportunities for opening new photochemical reaction pathways and controlling photoproduct distributions. We demonstrate photonic control of the 6π photocyclization of ortho-terphenyl to make 4a,4b-dihydrotriphenylene (DHT). Using pump-repump-probe spectroscopy we show that 1 + 1' excitation to a high-lying reactant electronic state generates a metastable species characterized by a red absorption feature that accompanies a repump-induced depletion in the one-photon trans-dihydro product (trans-DHT); signatures of the new photoproduct are clearer for a structural analogue of the reactant that is sterically inhibited against one-photon cyclization. Quantum-chemical computations support assignment of this species to cis-DHT, which is accessible photochemically along a disrotatory coordinate from high-lying electronic states reached by 1 + 1' excitation. We use time-resolved spectroscopy to track photochemical dynamics producing cis-DHT. In total, we demonstrate that selective multiphoton excitation opens a new photoreaction channel in these photocyclizing reactants by taking advantage of state-dependent correlations between reactant and product electronic states.


Assuntos
Crisenos/química , Luz , Ciclização , Isomerismo , Fótons , Teoria Quântica , Espectrofotometria
15.
Clin Epigenetics ; 13(1): 68, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33789736

RESUMO

BACKGROUND: Poor family emotional health (FEH) during childhood is prevalent and impactful, and likely confers similar neurodevelopmental risks as other adverse social environments. Pointed FEH study efforts are underdeveloped, and the mechanisms by which poor FEH are biologically embedded are unclear. The current exploratory study examined whether variability in 5-methyl-cytosine (5mC) and fronto-limbic grey matter volume may represent pathways through which FEH may become biologically embedded. RESULTS: In 98 university students aged 18-22 years, retrospective self-reported childhood FEH was associated with right hemisphere hippocampus (b = 10.4, p = 0.005), left hemisphere amygdala (b = 5.3, p = 0.009), and right hemisphere amygdala (b = 5.8, p = 0.016) volumes. After pre-processing and filtering to 5mC probes correlated between saliva and brain, analyses showed that childhood FEH was associated with 49 5mC principal components (module eigengenes; MEs) (prange = 3 × 10-6 to 0.047). Saliva-derived 5mC MEs partially mediated the association between FEH and right hippocampal volume (Burlywood ME indirect effect b = - 111, p = 0.014), and fully mediated the FEH and right amygdala volume relationship (Pink4 ME indirect effect b = - 48, p = 0.026). Modules were enriched with probes falling in genes with immune, central nervous system (CNS), cellular development/differentiation, and metabolic functions. CONCLUSIONS: Findings extend work highlighting neurodevelopmental variability associated with adverse social environment exposure during childhood by specifically implicating poor FEH, while informing a mechanism of biological embedding. FEH-associated epigenetic signatures could function as proxies of altered fronto-limbic grey matter volume associated with poor childhood FEH and inform further investigation into primarily affected tissues such as endocrine, immune, and CNS cell types.


Assuntos
Crisenos/análise , Relações Familiares/psicologia , Substância Cinzenta/fisiopatologia , Saliva/química , Estresse Psicológico/fisiopatologia , Estudantes/psicologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Estudos Retrospectivos , Estados Unidos , Adulto Jovem
16.
Chemosphere ; 276: 130108, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33711793

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are a group of persistent organic global environmental pollutants and cause harmful effects on human health. Here, we evaluated adverse effects of chrysene, which is a four-ring PAH and an important member of 16 priority PAHs, on the liver. Chrysene was detected in some common raw and cooked Chinese food samples. Hepatotoxicity including increased relative liver weight, hepatocyte swelling and degeneration, and elevated serum alanine aminotransferase (ALT) levels were observed in chrysene-exposed C57BL/6 mice. Glutamine treatment effectively ameliorated chrysene-induced mice liver injury by decreasing serum ALT levels. Chrysene induced mice hepatic glutathione depletion and oxidative DNA damage with increased 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. Hepatic expression levels of the aryl hydrocarbon receptor (AhR), AhR-related target genes including CYP1A1, CYP1A2 and CYP1B1, and AhR nuclear translocator (ARNT) were significantly increased in chrysene-exposed C57BL/6 mice. Chrysene induced mice hepatic mRNA levels of the nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2-mediated phase II detoxifying and antioxidant enzymes including NQO1, UGT1A1, UGT1A6, SULT1A1, GSTm1, GSTm3, Catalase (CAT), GPx1, and SOD2. We found that chrysene had toxic effects including increased relative liver weight and elevated serum ALT levels on AhR+/+ mice but not AhR-/- mice. Chrysene significantly induced hepatic mRNA levels of CYP1A1 and CYP1A2 in AhR+/+ mice but not AhR-/- mice. To our knowledge, this study is the first to demonstrate that hepatotoxicity causes by chrysene is dependent on AhR, and Nrf2 plays an important regulation role in protection against oxidative liver injury induced by chrysene.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Hidrocarbonetos Policíclicos Aromáticos , Animais , Crisenos , Citocromo P-450 CYP1A1 , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Hidrocarboneto Arílico/genética
17.
Aquat Toxicol ; 234: 105791, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33714762

RESUMO

Exposure to oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) at critical developmental time-points in fish models impairs red blood cell concentrations in a regioselective manner, with 2-hydroxychrysene being more potent than 6-hydroxychrysene. To better characterize this phenomenon, embryos of Japanese medaka (Oryzias latipes) were exposed to 2- or 6-hydroxychrysene (0.5, 2, or 5 µM) from 4 h-post-fertilization (hpf) to 7 d-post-fertilization. Following exposure, hemoglobin concentrations were quantified by staining fixed embryos with o-dianisidine (a hemoglobin-specific dye) and stained embryos were imaged using brightfield microscopy. Exposure to 2-hydroxychrysene resulted in a concentration-dependent decrease in hemoglobin relative to vehicle-exposed embryos, while only the highest concentration of 6-hydroxychrysene resulted in a significant decrease in hemoglobin. All tested concentrations of 2-hydroxychrysene also caused significant mortality (12.2 % ± 2.94, 38.9 % ± 14.4, 85.6 % ± 11.3), whereas mortality was not observed following exposure to 6-hydroxychrysene. Therefore, treatment of embryos with 2-hydroxychrysene at various developmental stages and durations was subsequently conducted to identify key developmental landmarks that may be targeted by 2-hydroxychrysene. A sensitive window of developmental toxicity to 2-hydroxychrysene was found between 52-100 hpf, with a 24 h exposure to 10 µM 2-hydroxychrysene resulting in significant anemia and mortality. Since exposure to 2-hydroxychrysene from 52 to 100 hpf, a window that includes liver morphogenesis in medaka, resulted in the highest magnitude of toxicity, liver development and function may have a role in 2-hydroxychrysene developmental toxicity.


Assuntos
Crisenos/toxicidade , Desenvolvimento Embrionário/efeitos dos fármacos , Oryzias/crescimento & desenvolvimento , Poluentes Químicos da Água/toxicidade , Animais , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Hemoglobinas/metabolismo , Estereoisomerismo
18.
Environ Sci Pollut Res Int ; 28(23): 29484-29497, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33560507

RESUMO

Numerous studies have focused on the response of meiofauna after exposure to polycyclic aromatic hydrocarbons (PAHs), but none has been devoted to their uptake into nematode body compartments. The present study monitored PAH uptake by Oncholaimus campylocercoides which was selected after 40 days in the laboratory through original protocols from natural sediments collected in the Old Harbor of Bizerte, Tunisia. To achieve the mono-species level, a grain size magnification was applied by gradually adding a biosubstrate made from either the crushed shells of Mytilus galloprovincialis or minced leaves of Posidonia oceanica. After selection, O. campylocercoides was cultured and fed with earthworm powder (560 mg.l-1). Thereafter, it was exposed for 3 weeks to phenanthrene and chrysene (38, 116, and 348 ppb). Fluorescence microscopy revealed higher intensities of PAHs at the spicules, mouths, and pharynges compared with the other organs considered. Moreover, the buccal fluorescence showed a significant correlation with that measured in the biosubstrate made with shells of M. galloprovincialis.


Assuntos
Nematoides , Fenantrenos , Hidrocarbonetos Policíclicos Aromáticos , Animais , Crisenos , Laboratórios , Microscopia de Fluorescência , Tunísia
19.
Chemosphere ; 263: 128267, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297211

RESUMO

Chrysene, a four-ring polycyclic aromatic hydrocarbon (PAH), is recalcitrant to biodegradation and persistent in the environment due to its low water solubility. Here, we investigated the atmospheric degradation process of chrysene initiated by OH radical in the presence of O2 and NOX using quantum chemical calculations. The reaction mechanisms were elucidated by density functional theory (DFT) at M06-2X/6-311++G(3df,2p)//M06-2X/6-311+G(d,p) level, and the kinetics calculations were conducted with Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The results show that the oxidation products of atmospheric chrysene are oxygenated PAHs (OPAHs) and nitro-PAHs (NPAHs), including nitro-chrysene, hydroxychrysene, hydroxychrysenone, 11-benzo[a]fluorenone and dialdehydes. Most of the products have deleterious effects on the environment and human beings due to their acute toxicity, carcinogenicity and mutagenicity. The overall rate constant for the reaction of chrysene with OH radical is 4.48 × 10-11 cm3 molecule-1 s-1 and the atmospheric lifetime of chrysene determined by OH radical is 6.4 h. The present work provided a comprehensive understanding on the degradation mechanisms and kinetics of chrysene, which could help to clarify its atmospheric fate and environmental risks.


Assuntos
Poluentes Atmosféricos , Atmosfera , Crisenos , Humanos , Radical Hidroxila , Cinética
20.
Hum Exp Toxicol ; 40(6): 1031-1044, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33345606

RESUMO

Chrysene, one of the basic polycyclic aromatic hydrocarbons (PAHs), has been reported to make damages to human health and living environment. Chronic obstructive pulmonary disease (COPD) is a progressive disorder with high morbidity and mortality. To investigate the role of chrysene in the development of COPD, male C57BL/6 mice were exposed to the cigarette smoke (CS) followed with the administration of chrysene. Morphological analyses indicated that chrysene caused earlier and severer pathological changes in CS-exposed mice. Besides, CS-exposed mice with chrysene treatment showed obvious collagen deposition, elevated α-smooth muscle actin (α-SMA) expression and reduced E-cadherin abundance at earlier stage, which suggested the acceleration and aggravation of pulmonary fibrosis. Moreover, quantification of leukocytes and pro-inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and lung tissues implied that chrysene significantly exacerbated the proceeding of inflammation in CS-exposed mice. Furthermore, significantly increased apoptotic rates, augmented expressions of apoptotic related proteins and highly expressed TRPV1 were determined in CS-exposed mice with chrysene treatment, which indicated the association between COPD pathogenesis and TRPV1 channel. In summary, our findings elucidate that chrysene accelerates the development of COPD in a murine model with new molecular mechanisms.


Assuntos
Apoptose/efeitos dos fármacos , Crisenos/toxicidade , Fumar Cigarros/efeitos adversos , Inflamação/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Animais , Modelos Animais de Doenças , Progressão da Doença , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
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