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Zhang Y, Gao L, Ai Q, Liu Y, Qiao L, Cheng X, Li J, Zhang L, Lyu B, Zheng M, Wu Y. Screening for compounds with bioaccumulation potential in breast milk using their retention behavior in two-dimensional gas chromatography. ENVIRONMENT INTERNATIONAL 2024; 190:108911. [PMID: 39067189 DOI: 10.1016/j.envint.2024.108911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 07/22/2024] [Accepted: 07/23/2024] [Indexed: 07/30/2024]
Abstract
Discovery of emerging pollutants in breast milk will be helpful for understanding the hazards to human health. However, it is difficult to identify key compounds among thousands present in complex samples. In this study, a method for screening compounds with bioaccumulation potential was developed. The method can decrease the number of compounds needing structural identification because the partitioning properties of bioaccumulative compounds can be mapped onto GC×GC chromatograms through their retention behaviors. Twenty pooled samples from seven provinces in China were analyzed. 1,286 compounds with bioaccumulation potential were selected from over 3,000 compounds. Sixty-two compounds, including aromatic compounds, phthalates, and phenolics etc., were identified with a high level of confidence and then quantified. Among them, twenty-seven compounds were found for the first time in breast milk. Three phthalate plasticizers and two phenolic antioxidants were found in significantly higher concentrations than other compounds. A toxicological priority index approach was applied to prioritize the compounds considering their concentrations, detection frequencies and eight toxic effects. The prioritization indicated that 13 compounds, including bis(2-ethylhexyl) phthalate, dibutyl phthalate, 1,3-di-tert-butylbenzene, phenanthrene, 2,6-di-tert-butyl-1,4-benzoquinone, 2,4-di-tert-butylphenol, and others, showed higher health risks. Meanwhile, some compounds with high risk for a particular toxic effect, such as benzothiazole and geranylacetone, were still noteworthy. This study is important for assessing the risks of human exposure to organic compounds.
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Affiliation(s)
- Yingxin Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lirong Gao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310000, China.
| | - Qiaofeng Ai
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yang Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lin Qiao
- College of Public Health, Zhengzhou University, Zhengzhou 450001, China
| | - Xin Cheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingguang Li
- Research Unit of Food Safety, Chinese Academy of Medical Sciences (No. 2019RU014); NHC Key Lab of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment (CFSA), Beijing 100022, China
| | - Lei Zhang
- Research Unit of Food Safety, Chinese Academy of Medical Sciences (No. 2019RU014); NHC Key Lab of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment (CFSA), Beijing 100022, China.
| | - Bing Lyu
- Research Unit of Food Safety, Chinese Academy of Medical Sciences (No. 2019RU014); NHC Key Lab of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment (CFSA), Beijing 100022, China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310000, China
| | - Yongning Wu
- Research Unit of Food Safety, Chinese Academy of Medical Sciences (No. 2019RU014); NHC Key Lab of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment (CFSA), Beijing 100022, China
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2
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Potter TD, Haywood N, Teixeira A, Hodges G, Barrett EL, Miller MA. Partitioning into phosphatidylcholine-cholesterol membranes: liposome measurements, coarse-grained simulations, and implications for bioaccumulation. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2023. [PMID: 37158124 DOI: 10.1039/d3em00081h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Membrane-water partitioning is an important physical property for the assessment of bioaccumulation and environmental impact. Here, we advance simulation methodology for predicting the partitioning of small molecules into lipid membranes and compare the computational predictions to experimental measurements in liposomes. As a step towards high-throughput screening, we present an automated mapping and parametrization procedure to produce coarse-grained models compatible with the Martini 3 force field. The methodology is general and can also be used for other applications where coarse-grained simulations are appropriate. This article addresses the effect on membrane-water partitioning of adding cholesterol to POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) membranes. Nine contrasting neutral, zwitterionic and charged solutes are tested. Agreement between experiment and simulation is generally good, with the most challenging cases being permanently charged solutes. For all solutes, partitioning is found to be insensitive to membrane cholesterol concentration up to 25% mole fraction. Hence, for assessment of bioaccumulation into a range of membranes (such as those found in fish), partitioning data measured in pure lipid membranes are still informative.
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Affiliation(s)
- Thomas D Potter
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom.
| | - Nicola Haywood
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, United Kingdom
| | - Alexandre Teixeira
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, United Kingdom
| | - Geoff Hodges
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, United Kingdom
| | - Elin L Barrett
- Safety and Environmental Assurance Centre, Unilever, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, United Kingdom
| | - Mark A Miller
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom.
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3
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Zhu T, Yu Y, Tao T. A comprehensive evaluation of liposome/water partition coefficient prediction models based on the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method: Challenges from different descriptor dimension reduction methods and machine learning algorithms. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130181. [PMID: 36257111 DOI: 10.1016/j.jhazmat.2022.130181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 10/09/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
The liposome/water partition coefficient (Klip/w) is a key parameter to evaluate the bioaccumulation potential of pollutants. Considering that it is difficult to determine the Klip/w values of all pollutants through experiments, researchers gradually developed models to predict it. However, there is currently no research on how to comprehensively evaluate prediction models and recommend a compelling optimal modeling method. To remedy the defect of single parameters in a traditional model comparison, the TOPSIS evaluation method, based on entropy weight, was first proposed. We use this method to comprehensively evaluate models from multiple angles in this study. Thirty QSPR models, including 3 descriptor dimension reduction methods and 10 algorithms (belonging to 4 tribes), were used to predict Klip/w and verify the effectiveness of the comprehensive assessment method. The results showed that RF (descriptor dimension reduction method), symbolism (tribes) and RF (algorithm) exhibited significant advantages in establishing the Klip/w value prediction model. At present, the application of TOPSIS in environmental model evaluations is almost absent. We hope that the proposed TOPSIS evaluation method can be applied to more chemical datasets and provide a more systematic and comprehensive basis for the application of the QSPR model in environmental studies and other fields.
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Affiliation(s)
- Tengyi Zhu
- School of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, China.
| | - Yan Yu
- School of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, China
| | - Tianyun Tao
- College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu, China
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4
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Han M, Zhang R, Yu K, Yan A, Li H, Zhang R, Zeng W, Zhang ZE, Liu F. Environmental fate and effects of PAHs in tropical mariculture ponds near the northern South China Sea: Rainfall plays a key role. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157442. [PMID: 35901874 DOI: 10.1016/j.scitotenv.2022.157442] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/09/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
The behavior and fate of PAHs are affected by multiple meteorological factors, but the main factors driving PAHs in tropical mariculture areas are still not clearly understood. This study continuously monitored PAHs in a few tropical land-based mariculture ponds, discussed their dynamic change trend, migration among the multiple media, and the relevant affected factors. Results indicated that PAHs were widely distributed in these environmental media, and the PAHs' concentration showed an obvious attenuation trend in the mariculture cycle. Wet deposition brought overwhelming majority atmospheric PAHs (92 % ± 5.7 %) to the aqueous system, and >72 % of these PAHs came from oil combustion-related sources and biomass combustion. Compared with the natural sea areas in the same region, mariculture ponds sediment could be changed from a sink at the early stage to a secondary release source of PAHs at the late stage of the rainy season, which intensifies the bioaccumulation of PAHs and the risk of edible carcinogenesis of aquatic products. Our research revealed that rainfall drove the occurrence and environmental behavior of PAHs in the tropical mariculture areas, while land-based mariculture ponds ecosystem affected the regional environmental fate of PAHs and weakened their transmission to the marine environment from land.
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Affiliation(s)
- Minwei Han
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Ruijie Zhang
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519080, China.
| | - Kefu Yu
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519080, China.
| | - Annan Yan
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Haolan Li
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Ruiling Zhang
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China; State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Weibin Zeng
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China
| | - Zheng-En Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Fang Liu
- Guangxi Laboratory on the Study of Coral Reefs in the South China Sea, Coral Reef Research Center of China, School of Marine Sciences, Guangxi University, Nanning 530004, China
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5
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Sun T, Wang S, Ji C, Li F, Wu H. Microplastics aggravate the bioaccumulation and toxicity of coexisting contaminants in aquatic organisms: A synergistic health hazard. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127533. [PMID: 34879523 DOI: 10.1016/j.jhazmat.2021.127533] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/12/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
There are ongoing controversies regarding the effects of microplastics (MPs) on the bioaccumulation and toxicity of coexisting contaminants in aquatic organisms. This study aims to quantitatively evaluate this issue based on 870 endpoints from 40 publications. It was shown that the presence of MPs significantly increased the bioaccumulation of co-contaminants by 31%, with high statistical power and without obvious publication bias. The aggravated bioaccumulation was also revealed by the strongly positive correlation between bioconcentration factors in the presence and the absence of MPs. Furthermore, the subgroup/regression analyses indicated that the vector effect of MPs on other chemicals was affected by multiple factors and their interactions, such as particle size and exposure time. In addition, a relatively comprehensive biomarker profile was recompiled from included studies to assess the changes in toxicity caused by combined exposure. Results confirmed that the presence of MPs obviously exacerbated the toxicity of co-contaminants by 18%, manifested by the potentiated cytotoxicity, endocrine disruption, immunotoxicity and oxidative stress, implying a synergistic health hazard. Ultimately, the mismatches between laboratory and field conditions were discussed, and the recommendations for future research were offered.
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Affiliation(s)
- Tao Sun
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, 264003, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Shuang Wang
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, 264003, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chenglong Ji
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, 264003, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences (CAS), Qingdao 266071, PR China
| | - Fei Li
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, 264003, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences (CAS), Qingdao 266071, PR China
| | - Huifeng Wu
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS); Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, 264003, PR China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences (CAS), Qingdao 266071, PR China.
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6
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Zhou M, Yang H, Li H, Gu L, Zhou Y, Li M. The effects of molecular weight and orientation on the membrane permeation and partitioning of polycyclic aromatic hydrocarbons: a computational study. Phys Chem Chem Phys 2022; 24:2158-2166. [PMID: 35005759 DOI: 10.1039/d1cp04777a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Membrane permeation and the partitioning of polycyclic aromatic hydrocarbons (PAHs) are crucial aspects affecting their carcinogenicity and mutagenicity. However, a clear understanding of these processes is still rare due to the difficulty of determining the details experimentally. Here, the interactions between PAHs and lipid bilayers were studied by molecular simulations, mainly to check the influence of molecular weight and orientation. The liposome-water partition coefficient (KLW), transmembrane time (τ), and permeability coefficient (P) of the PAHs were calculated by integrating free energy profiles from umbrella sampling. For selected PAHs, the membrane adsorption is a spontaneous process. The preferred location is near the CC bond and the orientation is related to the molecular structure. The P values of all the PAHs are basically the same order of magnitude, which means that the molecular weight contributes little to the process. As for KLW and τ, they show obvious increases with different molecular weights. Unconstrained simulations showed that a flat orientation on the membrane surface would prevent PAHs from being transported through the membrane. Highly hydrophobic driving forces are not always good for the absorption of PAHs, especially the formation of aggregates. In addition, the orientations and energetic barriers of PAHs near the midplane of the lipid bilayer explain the different transitions of high- and low-weight PAHs. This work provides molecular level details relating to the interactions of PAHs with lipid membranes, with significance for understanding the health effects of PAHs.
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Affiliation(s)
- Mi Zhou
- School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, China.,Institute of Chemical Materials, Chinese Academy of Engineering and Physics, 621900 Mianyang, China.
| | - Hong Yang
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, 621900 Mianyang, China.
| | - Huarong Li
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, 621900 Mianyang, China.
| | - Lingzhi Gu
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, 621900 Mianyang, China.
| | - Yang Zhou
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, 621900 Mianyang, China.
| | - Ming Li
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, 621900 Mianyang, China.
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7
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Potter T, Barrett EL, Miller MA. Automated Coarse-Grained Mapping Algorithm for the Martini Force Field and Benchmarks for Membrane-Water Partitioning. J Chem Theory Comput 2021; 17:5777-5791. [PMID: 34472843 PMCID: PMC8444346 DOI: 10.1021/acs.jctc.1c00322] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Indexed: 01/08/2023]
Abstract
With a view to high-throughput simulations, we present an automated system for mapping and parameterizing organic molecules for use with the coarse-grained Martini force field. The method scales to larger molecules and a broader chemical space than existing schemes. The core of the mapping process is a graph-based analysis of the molecule's bonding network, which has the advantages of being fast, general, and preserving symmetry. The parameterization process pays special attention to coarse-grained beads in aromatic rings. It also includes a method for building efficient and stable frameworks of constraints for molecules with structural rigidity. The performance of the method is tested on a diverse set of 87 neutral organic molecules and the ability of the resulting models to capture octanol-water and membrane-water partition coefficients. In the latter case, we introduce an adaptive method for extracting partition coefficients from free-energy profiles to take into account the interfacial region of the membrane. We also use the models to probe the response of membrane-water partitioning to the cholesterol content of the membrane.
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Affiliation(s)
- Thomas
D. Potter
- Department
of Chemistry, Durham University, South Road, Durham DH1 3LE, United
Kingdom
| | - Elin L. Barrett
- Unilever
Safety and Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedfordshire MK44 1LQ, United Kingdom
| | - Mark A. Miller
- Department
of Chemistry, Durham University, South Road, Durham DH1 3LE, United
Kingdom
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8
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Duncan KM, Steel WH, Walker RA. Amino acids change solute affinity for lipid bilayers. Biophys J 2021; 120:3676-3687. [PMID: 34310940 PMCID: PMC8456291 DOI: 10.1016/j.bpj.2021.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 06/19/2021] [Accepted: 07/20/2021] [Indexed: 11/26/2022] Open
Abstract
Time-resolved fluorescence and differential scanning calorimetry (DSC) were used to examine how two amino acids, L-phenylalanine (L-PA) and N-acetyl-DL-tryptophan (NAT), affect the temperature-dependent membrane affinity of two structurally similar coumarin solutes for 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) vesicles. The 7-aminocoumarin solutes, coumarin 151 (C151) and coumarin 152 (C152), differ in their substitution at amine position-C151 is a primary amine, and C152 is a tertiary amine-and both solutes show different tendencies to associate with lipid bilayers consistent with differences in their respective log-P-values. Adding L-PA to the DPPC vesicle solution did not change C151's propensity to remain freely solvated in aqueous solution, but C152 showed a greater tendency to partition into the hydrophobic bilayer interior at temperatures below DPPC's gel-liquid crystalline transition temperature (Tgel-lc). This finding is consistent with L-PA's ability to enhance membrane permeability by disrupting chain-chain interactions. Adding NAT to DPPC-vesicle-containing solutions changed C151 and C152 affinity for the DPPC membranes in unexpected ways. DSC data show that NAT interacts strongly with the lipid bilayer, lowering Tgel-lc by up to 2°C at concentrations of 10 mM. These effects disappear when either C151 or C152 is added to solution at concentrations below 10 μM, and Tgel-lc returns to a value consistent with unperturbed DPPC bilayers. Together with DSC results, fluorescence data imply that NAT promotes coumarin adsorption to the vesicle bilayer surface. NAT's effects diminish above Tgel-lc and imply that unlike L-PA, NAT does not penetrate into the bilayer but instead remains adsorbed to the bilayer's exterior. Taken in their entirety, these discoveries suggest that amino acids-and by inference, polypeptides and proteins-change solute affinity for lipid bilayers with specific effects that depend on individualized amino-acid-lipid-bilayer interactions.
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Affiliation(s)
- Katelyn M Duncan
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana
| | - William H Steel
- Department of Chemistry, York College of Pennsylvania, York, Pennsylvania
| | - Robert A Walker
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana; Montana Materials Science Program, Montana State University, Bozeman, Montana.
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Maculewicz J, Świacka K, Kowalska D, Stepnowski P, Stolte S, Dołżonek J. In vitro methods for predicting the bioconcentration of xenobiotics in aquatic organisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 739:140261. [PMID: 32758962 DOI: 10.1016/j.scitotenv.2020.140261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/10/2020] [Accepted: 06/14/2020] [Indexed: 06/11/2023]
Abstract
The accumulation of anthropogenic chemical substances in aquatic organisms is an immensely important issue from the point of view of environmental protection. In the context of the increasing number and variety of compounds that may potentially enter the environment, there is a need for efficient and reliable solutions to assess the risks. However, the classic approach of testing with fish or other animals is not sufficient. Due to very high costs, significant time and labour intensity, as well as ethical concerns, in vivo methods need to be replaced by new laboratory-based tools. So far, many models have been developed to estimate the bioconcentration potential of chemicals. However, most of them are not sufficiently reliable and their predictions are based on limited input data, often obtained with doubtful quality. The octanol-water partition coefficient is still often used as the main laboratory tool for estimating bioconcentration. However, according to current knowledge, this method can lead to very unreliable results, both for neutral species and, above all, for ionic compounds. It is therefore essential to start using new, more advanced and credible solutions on a large scale. Over the last years, many in vitro methods have been newly developed or improved, allowing for a much more adequate estimation of the bioconcentration potential. Therefore, the aim of this work was to review the most recent laboratory methods for assessing the bioconcentration potential and to evaluate their applicability in further research.
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Affiliation(s)
- Jakub Maculewicz
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland.
| | - Klaudia Świacka
- Department of Experimental Ecology of Marine Organisms, Institute of Oceanography, University of Gdansk, Av. Pilsudskiego 46, 81-378 Gdynia, Poland
| | - Dorota Kowalska
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Piotr Stepnowski
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Stefan Stolte
- Faculty of Environmental Sciences, Department of Hydrosciences, Institute of Water Chemistry, Technische Universität Dresden, Bergstrasse 66, 01069 Dresden, Germany
| | - Joanna Dołżonek
- Department of Environmental Analysis, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
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10
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Lee SY, Kwon JH. Enhancement of Toxic Efficacy of Alkylated Polycyclic Aromatic Hydrocarbons Transformed by Sphingobium quisquiliarum. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17176416. [PMID: 32899285 PMCID: PMC7503419 DOI: 10.3390/ijerph17176416] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 11/16/2022]
Abstract
Alkylated polycyclic aromatic hydrocarbons (PAHs) are abundant in crude oils and refined petroleum products and are considered as major contributors to the toxicity of spilled oils. In this study, the microbial degradation of model (alkylated) PAHs (i.e., phenanthrene, 3-methylphenanthrene, 3,6-dimethylphenanthrene (36DMPhe), pyrene, and 1-methylpyrene (1MP)) by the bacterium Sphingobium quisquiliarum EPA505, a known degrader of PAHs, was studied. To evaluate the toxic potential of the metabolic products, reaction mixtures containing metabolites of 36DMPhe and 1MP were fractionated by high-performance liquid chromatography, and their effects on the luminescence inhibition of Aliivibrio fischeri were evaluated. Although the luminescence inhibition of 36DMPhe and 1MP at their solubility levels was not observed, inhibition was observed in their metabolite fractions at the solubility limit of their parent molecule. This indicates that initial biotransformation increases the toxicity of alkylated PAHs because of the increased solubility and/or inherent toxicity of metabolites. Qualitative analysis of the metabolite fractions suggested that mono-oxidation of the methyl group is the main metabolic pathway of 36DMPhe and 1MP.
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11
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Escher BI, Henneberger L, König M, Schlichting R, Fischer FC. Cytotoxicity Burst? Differentiating Specific from Nonspecific Effects in Tox21 in Vitro Reporter Gene Assays. ENVIRONMENTAL HEALTH PERSPECTIVES 2020; 128:77007. [PMID: 32700975 PMCID: PMC7377237 DOI: 10.1289/ehp6664] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 06/16/2020] [Accepted: 07/02/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND High-throughput screening of chemicals with in vitro reporter gene assays in Tox21 has produced a large database on cytotoxicity and specific modes of action. However, the validity of some of the reported activities is questionable due to the "cytotoxicity burst," which refers to the supposition that many stress responses are activated in a nonspecific way at concentrations close to cell death. OBJECTIVES We propose a pragmatic method to identify whether reporter gene activation is specific or cytotoxicity-triggered by comparing the measured effects with baseline toxicity. METHODS Baseline toxicity, also termed narcosis, is the minimal toxicity any chemical causes. Quantitative structure-activity relationships (QSARs) developed for baseline toxicity in mammalian reporter gene cell lines served as anchors to define the chemical-specific threshold for the cytotoxicity burst and to evaluate the degree of specificity of the reporter gene activation. Measured 10% effect concentrations were related to measured or QSAR-predicted 10% cytotoxicity concentrations yielding specificity ratios (SR). We applied this approach to our own experimental data and to ∼ 8,000 chemicals that were tested in six of the high-throughput Tox21 reporter gene assays. RESULTS Confirmed baseline toxicants activated reporter gene activity around cytotoxic concentrations triggered by the cytotoxicity burst. In six Tox21 assays, 37%-87% of the active hits were presumably caused by the cytotoxicity burst (SR < 1 ) and only 2%-14% were specific with SR ≥ 10 against experimental cytotoxicity but 75%-97% were specific against baseline toxicity. This difference was caused by a large fraction of chemicals showing excess cytotoxicity. CONCLUSIONS The specificity analysis for measured in vitro effects identified whether a cytotoxicity burst had likely occurred. The SR-analysis not only prevented false positives, but it may also serve as measure for relative effect potency and can be used for quantitative in vitro-in vivo extrapolation and risk assessment of chemicals. https://doi.org/10.1289/EHP6664.
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Affiliation(s)
- Beate I. Escher
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
- Environmental Toxicology, Center for Applied Geoscience, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Luise Henneberger
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
| | - Maria König
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
| | - Rita Schlichting
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
| | - Fabian C. Fischer
- Department of Cell Toxicology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
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12
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Henneberger L, Mühlenbrink M, Heinrich DJ, Teixeira A, Nicol B, Escher BI. Experimental Validation of Mass Balance Models for in Vitro Cell-Based Bioassays. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:1120-1127. [PMID: 31852189 DOI: 10.1021/acs.est.9b06144] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The freely dissolved concentration in the assay medium (Cfree) and the total cellular concentration (Ccell) are essential input parameters for quantitative in vitro-to-in vivo extrapolations (QIVIVE), but available prediction tools for Cfree and Ccell have not been sufficiently validated with experimental data. In this study, medium-water distribution ratios (DFBS/w) and cell-water distribution ratios (Dcell/w) for four different cells lines were determined experimentally for 12 neutral and five ionizable chemicals. Literature data for seven organic acids were added to the dataset, leading to 24 chemicals in total. A mass balance model based on bovine serum albumin-water (DBSA/w) and liposome-water distribution ratios (Dlip/w) of the chemicals was used to calculate DFBS/w and Dcell/w. For all neutral and basic test chemicals, the mass balance model predicted DFBS/w and Dcell/w within a factor of 3 and 3.4, respectively, indicating that existing models can reliably predict Cfree and Ccell for these chemicals. For organic acids, a further refinement of the model will be required as large deviations between modeled and measured binding to assay medium and cells of up to a factor of 370 were found. Furthermore, saturation of medium proteins should be further explored for organic acids and neutral chemicals with moderate hydrophobicity.
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Affiliation(s)
- Luise Henneberger
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research-UFZ , Permoserstr. 15 , 04318 Leipzig , Germany
| | - Marie Mühlenbrink
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research-UFZ , Permoserstr. 15 , 04318 Leipzig , Germany
| | - Daniel J Heinrich
- Environmental Toxicology, Center for Applied Geoscience , Eberhard Karls University Tübingen , 72074 Tübingen , Germany
| | - Alexandre Teixeira
- Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedfordshire MK44 1LQ , U.K
| | - Beate Nicol
- Safety & Environmental Assurance Centre , Colworth Science Park , Sharnbrook , Bedfordshire MK44 1LQ , U.K
| | - Beate I Escher
- Department of Cell Toxicology , Helmholtz Centre for Environmental Research-UFZ , Permoserstr. 15 , 04318 Leipzig , Germany
- Environmental Toxicology, Center for Applied Geoscience , Eberhard Karls University Tübingen , 72074 Tübingen , Germany
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13
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Lin S, Yang X, Liu H. Development of liposome/water partition coefficients predictive models for neutral and ionogenic organic chemicals. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 179:40-49. [PMID: 31026749 DOI: 10.1016/j.ecoenv.2019.04.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 04/06/2019] [Accepted: 04/11/2019] [Indexed: 06/09/2023]
Abstract
Membrane/water partition coefficient (Km/w) is a vital parameter used to characterize the membrane permeability of compounds. Considering the Km/w value is difficult to observe experimentally for real biological membranes, liposome/water partition coefficient (Klip/w) is employed to approximate Km/w. Here, quantitative structure property relationship (QSPR) models for logKlip/w of the neutral organic chemicals and the neutral form of ionogenic organic chemicals (IOCs) (logKlip/w-neutral), ionic form of IOCs (logKlip/w-ionic), the speciation-corrected liposome-water distribution ratios at a pH = 7.40 (logDlip/w-(pH=7.40)) were developed. In the modeling, two modeling methods (multiple linear regressions (MLR) and k-nearest neighbor (kNN)) were used. The predictive variables employed here could be calculated from the molecular structure directly. For logKlip/w-neutral and logDlip/w-(pH=7.40), the logKOW and logDOW-based, non-logKOW and non-logDOW-based kNN-QSPR and MLR-QSPR models were developed, respectively. The evaluation results implied that the predictive performance of kNN-QSPR models is better than that of MLR-QSPR models. For logKlip/w-ionic, only one acceptable MLR-QSPR model was developed for cation and anion, respectively. The model quality of the derived models was evaluated following the OECD QSPR models validation guideline. The determination coefficient (R2), leave-one-out cross validation Q2 (Q2LOO) and bootstrapping coefficient (Q2BOOT), the external validation coefficient (Q2EXT) of all the models met the acceptable criteria (Q2 > 0.600, R2 > 0.700); while the root-mean-square error (RMSE) range from 0.351 to 0.857. All the results implied that the models had good goodness-of-fit, robustness and predictive ability. Therefore, the developed models could be used to fill the data gap for substances within the applicability domain on their missing logKlip/w-neutral, logKlip/w-ionic, logDlip/w-(pH=7.40) values.
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Affiliation(s)
- Shiyu Lin
- Key Laboratory of New Membrane Materials, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China
| | - Xianhai Yang
- Key Laboratory of New Membrane Materials, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
| | - Huihui Liu
- Key Laboratory of New Membrane Materials, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
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14
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Henneberger L, Mühlenbrink M, König M, Schlichting R, Fischer FC, Escher BI. Quantification of freely dissolved effect concentrations in in vitro cell-based bioassays. Arch Toxicol 2019; 93:2295-2305. [DOI: 10.1007/s00204-019-02498-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 06/17/2019] [Indexed: 02/05/2023]
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15
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Roh JY, Kim PG, Kwon JH. Comparative study of oxidative stress caused by anthracene and alkyl-anthracenes in Caenorhabditis elegans. ENVIRONMENTAL HEALTH AND TOXICOLOGY 2018; 33:e2018006. [PMID: 29631345 PMCID: PMC5903033 DOI: 10.5620/eht.e2018006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 02/26/2018] [Indexed: 05/08/2023]
Abstract
Oxidative stress was evaluated for anthracene (Ant) and alkyl-Ants (9-methylanthracene [9-MA] and 9,10-dimethylanthracene [9,10-DMA]) in Caenorhabditis elegans to compare changes in toxicity due to the degree of alkylation. Worms were exposed at 1) the same external exposure concentration and 2) the maximum water-soluble concentration. Formation of reactive oxygen species, superoxide dismutase activity, total glutathione concentration, and lipid peroxidation were determined under constant exposure conditions using passive dosing. The expression of oxidative stress-related genes (daf-2, sir-2.1, daf-16, sod-1, sod-2, sod-3 and cytochrome 35A/C family genes) was also investigated to identify and compare changes in the genetic responses of C. elegans exposed to Ant and alkyl-Ant. At the same external concentration, 9,10-DMA induced the greatest oxidative stress, as evidenced by all indicators, except for lipid peroxidation, followed by 9-MA and Ant. Interestingly, 9,10-DMA led to greater oxidative stress than 9-MA and Ant when worms were exposed to the maximum water-soluble concentration, although the maximum water-soluble concentration of 9,10-DMA is the lowest. Increased oxidative stress by alkyl-Ants would be attributed to higher lipid-water partition coefficient and the π electron density in aromatic rings by alkyl substitution, although this supposition requires further confirmation.
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Affiliation(s)
- Ji-Yeon Roh
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea
- Unit of Industrial Chemical & Biocides, Knoell Korea Ltd., Seoul, Korea
| | - Pil-Gon Kim
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea
| | - Jung-Hwan Kwon
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea
- Corresponding author: Jung-Hwan Kwon Division of Environmental Science and Ecological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea E-mail:
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16
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Kang HJ, Lee SY, Kwon JH. Physico-chemical properties and toxicity of alkylated polycyclic aromatic hydrocarbons. JOURNAL OF HAZARDOUS MATERIALS 2016; 312:200-207. [PMID: 27037474 DOI: 10.1016/j.jhazmat.2016.03.051] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/12/2016] [Accepted: 03/19/2016] [Indexed: 06/05/2023]
Abstract
Crude oil and refined petroleum products contain many polycyclic and heterocyclic aromatic hydrocarbons, in particular, alkylated PAHs. Although alkylated PAHs are found in significantly higher quantities than their corresponding unsubstituted PAHs, the most studies on the physico-chemical properties and toxicities of these compounds have been conducted on unsubstituted PAHs. In this study, we measured crucial physico-chemical properties (i.e., water solubility, partition coefficients between polydimethylsiloxane and water (KPDMSw), and partition coefficient between liposomes and water (Klipw)) of selected alkylated PAHs, and evaluated their toxicity using the luminescence inhibition of Aliivibrio fischeri and growth inhibition of Raphidocelis subcapitata. In general, the logarithms of these properties for alkylated PAHs showed good linear correlations with log Kow, as did those for unsubstituted PAHs. Changes in molecular symmetry on the introduction of alkyl groups on aromatic ring structure significantly altered water solubility. The inhibition of bacterial luminescence and algal growth by alkylated PAHs can be explained well by the baseline toxicity hypothesis, and good linear relationships between log Kow or log Klipw and log (1/EC50) were found.
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Affiliation(s)
- Hyun-Joong Kang
- Division of Environmental Science and Ecological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul02841, Republic of Korea
| | - So-Young Lee
- Division of Environmental Science and Ecological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul02841, Republic of Korea
| | - Jung-Hwan Kwon
- Division of Environmental Science and Ecological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul02841, Republic of Korea.
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17
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Jonker MTO. Determining octanol-water partition coefficients for extremely hydrophobic chemicals by combining "slow stirring" and solid-phase microextraction. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2016; 35:1371-7. [PMID: 26550770 DOI: 10.1002/etc.3300] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/26/2015] [Accepted: 11/05/2015] [Indexed: 05/14/2023]
Abstract
Octanol-water partition coefficients (KOW ) are widely used in fate and effects modeling of chemicals. Still, high-quality experimental KOW data are scarce, in particular for very hydrophobic chemicals. This hampers reliable assessments of several fate and effect parameters and the development and validation of new models. One reason for the limited availability of experimental values may relate to the challenging nature of KOW measurements. In the present study, KOW values for 13 polycyclic aromatic hydrocarbons were determined with the gold standard "slow-stirring" method (log KOW 4.6-7.2). These values were then used as reference data for the development of an alternative method for measuring KOW . This approach combined slow stirring and equilibrium sampling of the extremely low aqueous concentrations with polydimethylsiloxane-coated solid-phase microextraction fibers, applying experimentally determined fiber-water partition coefficients. It resulted in KOW values matching the slow-stirring data very well. Therefore, the method was subsequently applied to a series of 17 moderately to extremely hydrophobic petrochemical compounds. The obtained KOW values spanned almost 6 orders of magnitude, with the highest value measuring 10(10.6) . The present study demonstrates that the hydrophobicity domain within which experimental KOW measurements are possible can be extended with the help of solid-phase microextraction and that experimentally determined KOW values can exceed the proposed upper limit of 10(9) . Environ Toxicol Chem 2016;35:1371-1377. © 2015 SETAC.
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Affiliation(s)
- Michiel T O Jonker
- Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands
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18
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Wang Y, Yang X, Wang J, Cong Y, Mu J, Jin F. A DFT-based toxicity QSAR study of aromatic hydrocarbons to Vibrio fischeri: Consideration of aqueous freely dissolved concentration. JOURNAL OF HAZARDOUS MATERIALS 2016; 308:149-156. [PMID: 26812082 DOI: 10.1016/j.jhazmat.2016.01.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/21/2015] [Accepted: 01/04/2016] [Indexed: 06/05/2023]
Abstract
In the present study, quantitative structure-activity relationship (QSAR) techniques based on toxicity mechanism and density functional theory (DFT) descriptors were adopted to develop predictive models for the toxicity of alkylated and parent aromatic hydrocarbons to Vibrio fischeri. The acute toxicity data of 17 aromatic hydrocarbons from both literature and our experimental results were used to construct QSAR models by partial least squares (PLS) analysis. With consideration of the toxicity process, the partition of aromatic hydrocarbons between water phase and lipid phase and their interaction with the target biomolecule, the optimal QSAR model was obtained by introducing aqueous freely dissolved concentration. The high statistical values of R(2) (0.956) and Q(CUM)(2) (0.942) indicated that the model has good goodness-of-fit, robustness and internal predictive power. The average molecular polarizability (α) and several selected thermodynamic parameters reflecting the intermolecular interactions played important roles in the partition of aromatic hydrocarbons between the water phase and biomembrane. Energy of the highest occupied molecular orbital (E(HOMO)) was the most influential descriptor which dominated the toxicity of aromatic hydrocarbons through the electron-transfer reaction with biomolecules. The results demonstrated that the adoption of freely dissolved concentration instead of nominal concentration was a beneficial attempt for toxicity QSAR modeling of hydrophobic organic chemicals.
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Affiliation(s)
- Ying Wang
- Key Laboratory for Ecological Environment in Coastal Areas, State Oceanic Administration, National Marine Environmental Monitoring Center, No. 42 Linghe Street, Dalian 116023, China
| | - Xianhai Yang
- Nanjing Institute of Environmental Sciences, Ministry of Environmental Protection, Jiang-wang-miao Street, Nanjing 210042, China
| | - Juying Wang
- Key Laboratory for Ecological Environment in Coastal Areas, State Oceanic Administration, National Marine Environmental Monitoring Center, No. 42 Linghe Street, Dalian 116023, China.
| | - Yi Cong
- Key Laboratory for Ecological Environment in Coastal Areas, State Oceanic Administration, National Marine Environmental Monitoring Center, No. 42 Linghe Street, Dalian 116023, China
| | - Jingli Mu
- Key Laboratory for Ecological Environment in Coastal Areas, State Oceanic Administration, National Marine Environmental Monitoring Center, No. 42 Linghe Street, Dalian 116023, China
| | - Fei Jin
- Key Laboratory for Ecological Environment in Coastal Areas, State Oceanic Administration, National Marine Environmental Monitoring Center, No. 42 Linghe Street, Dalian 116023, China
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19
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Golius A, Gorb L, Michalkova Scott A, Hill FC, Shukla M, Goins AB, Johnson DR, Leszczynski J. Experimental and computational study of membrane affinity for selected energetic compounds. CHEMOSPHERE 2016; 148:322-327. [PMID: 26820779 DOI: 10.1016/j.chemosphere.2016.01.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 12/14/2015] [Accepted: 01/04/2016] [Indexed: 06/05/2023]
Abstract
The affinity of various energetic compounds for a biological membrane was investigated using experimental and computational techniques. We measured octanol-water (log(Kow)) and liposome-water (log(Klipw)) partition coefficients for the following chemicals: trinitrotoluene (TNT), 2,4-dinitrotoluene (2,4-DNT), 2,6-dinitrotoluene (2,6-DNT), 2,4-dinitroanisole (DNAN), 2methoxy-5-nitrophenol (2M5NP), 2,4,6-trinitrobenzene (TNB), and 2,4-dinitrophenol (2,4-DNP). In order to determine log(Klipw) experimentally, we used artificial solid supported lipid liposomes produced under trade mark TRANSIL. Log(Kow) value were predicted with several program packages including the COSMOthermX software. Log(Klipw) were estimated with COSMOmic as implemented in the COSMOthermX program package. In order to verify accuracy of our experimentally obtained results, we performed basic statistical analysis of data taken from the literature. We concluded that compounds considered in this study possess a moderate ability to penetrate into membranes. Comparison of both coefficients has shown that in general, the log(Kow) values are slightly smaller than log(Klipw).
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Affiliation(s)
- Anastasiia Golius
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS, USA
| | | | | | - Frances C Hill
- U.S. Army Engineer Research and Development Center, Vicksburg, MS, USA
| | - Manoj Shukla
- U.S. Army Engineer Research and Development Center, Vicksburg, MS, USA
| | | | | | - Jerzy Leszczynski
- Department of Chemistry and Biochemistry, Jackson State University, Jackson, MS, USA.
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20
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Bittermann K, Spycher S, Goss KU. Comparison of different models predicting the phospholipid-membrane water partition coefficients of charged compounds. CHEMOSPHERE 2016; 144:382-91. [PMID: 26383265 DOI: 10.1016/j.chemosphere.2015.08.065] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 05/19/2023]
Abstract
A large fraction of commercially used chemicals is ionizable. This results in the need for mechanistic models to describe the physicochemical properties of ions, like the membrane-water partition coefficient (K(mw)), which is related to toxicity and bioaccumulation. In this work we compare 3 different and already existing modelling approaches to describe the liposome-water partition coefficient (K(lipw)) of organic ions, including 36 cations, 56 anions, 2 divalent cations and 2 zwitterions (plus 207 neutral compounds for ensuring model consistency). 1) The empirical correlation with the octanol-water partition coefficient of the corresponding neutral species yielded better results for the prediction of anions (RMSE = 0.79) than for cations (RMSE = 1.14). Though describing most anions reasonably well, the lack of mechanistic basis and the poor performance for cations constrain the usage of this model. 2) The polyparameter linear free energy relationship (pp-LFER) model performs worse (RMSE = 1.26/1.12 for anions/cations). The different physicochemical environments, due to different sorption depths into the membrane of the different species, cannot be described with a single pp-LFER model. 3) COSMOmic is based on quantum chemistry and fluid phase thermodynamics and has the widest applicability domain. It was the only model applicable for multiply charged ions and gave the best results for anions (RMSE = 0.66) and cations (RMSE = 0.71). We expect COSMOmic to contribute to a better estimation of the environmental risk of ionizable emerging pollutants.
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Affiliation(s)
- Kai Bittermann
- UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, D-04318 Leipzig, Germany.
| | - Simon Spycher
- ELPR Ltd., Litzibuch, CH-8966 Oberwil-Lieli, Switzerland.
| | - Kai-Uwe Goss
- UFZ - Helmholtz Centre for Environmental Research, Permoserstr. 15, D-04318 Leipzig, Germany; University of Halle-Wittenberg, Institute of Chemistry, Kurt Mothes Str. 2, D-06120 Halle, Germany.
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21
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Tanoue R, Nomiyama K, Nakamura H, Kim JW, Isobe T, Shinohara R, Kunisue T, Tanabe S. Uptake and Tissue Distribution of Pharmaceuticals and Personal Care Products in Wild Fish from Treated-Wastewater-Impacted Streams. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:11649-58. [PMID: 26348835 DOI: 10.1021/acs.est.5b02478] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A fish plasma model (FPM) has been proposed as a screening technique to prioritize potential hazardous pharmaceuticals to wild fish. However, this approach does not account for inter- or intraspecies variability of pharmacokinetic and pharmacodynamic parameters. The present study elucidated the uptake potency (from ambient water), tissue distribution, and biological risk of 20 pharmaceutical and personal care product (PPCP) residues in wild cyprinoid fish inhabiting treated-wastewater-impacted streams. In order to clarify the uncertainty of the FPM for PPCPs, we compared the plasma bioaccumulation factor in the field (BAFplasma = measured fish plasma/ambient water concentration ratio) with the predicted plasma bioconcentration factor (BCFplasma = fish plasma predicted by use of theoretical partition coefficients/ambient water concentration ratio) in the actual environment. As a result, the measured maximum BAFplasma of inflammatory agents was up to 17 times higher than theoretical BCFplasma values, leading to possible underestimation of toxicological risk on wild fish. When the tissue-blood partition coefficients (tissue/blood concentration ratios) of PPCPs were estimated, higher transportability into tissues, especially the brain, was found for psychotropic agents, but brain/plasma ratios widely varied among individual fish (up to 28-fold). In the present study, we provide a valuable data set on the intraspecies variability of PPCP pharmacokinetics, and our results emphasize the importance of determining PPCP concentrations in possible target organs as well as in the blood to assess the risk of PPCPs on wild fish.
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Affiliation(s)
- Rumi Tanoue
- Center for Marine Environmental Studies, Ehime University , 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Kei Nomiyama
- Center for Marine Environmental Studies, Ehime University , 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Haruna Nakamura
- Graduate School of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto , 3-1-100 Tsukide, Kumamoto 862-8502, Japan
| | - Joon-Woo Kim
- Monitoring and Analysis Division, Seamangeum Regional Environmental Office , 100 Seogok-ro, Wansan-gu, Jeonju-si, Jeollabuk-do 560-870, Republic of Korea
| | - Tomohiko Isobe
- National Institute for Environmental Studies , 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan
| | - Ryota Shinohara
- Graduate School of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto , 3-1-100 Tsukide, Kumamoto 862-8502, Japan
| | - Tatsuya Kunisue
- Center for Marine Environmental Studies, Ehime University , 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
| | - Shinsuke Tanabe
- Center for Marine Environmental Studies, Ehime University , 2-5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
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Genheden S, Essex JW. A simple and transferable all-atom/coarse-grained hybrid model to study membrane processes. J Chem Theory Comput 2015; 11:4749-59. [PMID: 26574264 DOI: 10.1021/acs.jctc.5b00469] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We present an efficient all-atom/coarse-grained hybrid model and apply it to membrane processes. This model is an extension of the all-atom/ELBA model applied previously to processes in water. Here, we improve the efficiency of the model by implementing a multiple-time step integrator that allows the atoms and the coarse-grained beads to be propagated at different timesteps. Furthermore, we fine-tune the interaction between the atoms and the coarse-grained beads by computing the potential of mean force of amino acid side chain analogs along the membrane normal and comparing to atomistic simulations. The model was independently validated on the calculation of small-molecule partition coefficients. Finally, we apply the model to membrane peptides. We studied the tilt angle of the Walp23 and Kalp23 helices in two different model membranes and the stability of the glycophorin A dimer. The model is efficient, accurate, and straightforward to use, as it does not require any extra interaction particles, layers of atomistic solvent molecules or tabulated potentials, thus offering a novel, simple approach to study membrane processes.
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Affiliation(s)
- Samuel Genheden
- School of Chemistry, University of Southampton, Highfield , SO17 1BJ, Southampton, United Kingdom
| | - Jonathan W Essex
- School of Chemistry, University of Southampton, Highfield , SO17 1BJ, Southampton, United Kingdom
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23
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Fernandez LA, Gschwend PM. Predicting bioaccumulation of polycyclic aromatic hydrocarbons in soft-shelled clams (Mya arenaria) using field deployments of polyethylene passive samplers. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2015; 34:993-1000. [PMID: 25598269 DOI: 10.1002/etc.2892] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/13/2014] [Accepted: 01/13/2015] [Indexed: 05/21/2023]
Abstract
Biota-sediment accumulation factors (BSAF), frequently used to predict tissue concentrations of organisms living within and above sediments contaminated with hydrophobic organic chemicals, often produce inaccurate estimates. Hence, freely dissolved porewater concentrations, CW , have also been investigated as predictors of organism tissue concentrations, but they are more difficult to measure than bulk sediment concentrations (used with BSAF). In situ passive sampling methods, however, make it possible to deduce CW with less effort than required to measure the value directly and make it possible to relate CW with tissue concentrations of undisturbed, native organisms. In the present study, polyethylene passive samplers containing performance reference compounds (d10-phenanthrene, d10-pyrene, and d12-chrysene) were deployed in diverse sediment beds near Boston, Massachusetts, USA, for a 1-wk period. Clams (Mya arenaria) and sediments were then collected from the deployed sediment beds. Concentrations of 3 polycyclic aromatic hydrocarbons (PAHs; phenanthrene, pyrene, and chrysene) were measured in the porewaters, in clam tissues, and in the bulk sediment. Biota-sediment accumulation factors and polyethylene-deduced CW were used to predict organism tissue concentrations. Ratios of predicted-to-measured values showed that the BSAF method over-predicted tissue concentrations in M. arenaria by up to 2 orders of magnitude. The polyethylene-deduced CW method resulted in average ratios closer to 1 (0.43 ± 0.26, 3.7 ± 2.5, and 1.1 ± 1.2 for phenanthrene, pyrene, and chrysene, respectively, N = 26, uncertainty = ± 1σ).
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Affiliation(s)
- Loretta A Fernandez
- Departments of Civil and Environmental Engineering and Marine and Environmental Sciences, Northeastern University, Boston, Massachusetts, USA; Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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van der Heijden SA, Hermens JLM, Sinnige TL, Mayer P, Gilbert D, Jonker MTO. Determining high-quality critical body residues for multiple species and chemicals by applying improved experimental design and data interpretation concepts. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:1879-1887. [PMID: 25594358 DOI: 10.1021/es505078r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ecotoxicological effect data are generally expressed as effective concentrations in the external exposure medium and do thus not account for differences in chemical uptake, bioavailability, and metabolism, which can introduce substantial data variation. The Critical Body Residue (CBR) concept provides clear advantages, because it links effects directly to the internal exposure. Using CBRs instead of external concentrations should therefore reduce variability. For compounds that act via narcosis even a constant CBR has been proposed. Despite the expected uniformity, CBR values for these compounds still show large variability, possibly due to biased and inconsistent experimental testing. In the present study we tested whether variation in CBR data can be substantially reduced when using an improved experimental design and avoiding confounding factors. The aim was to develop and apply a well-defined test protocol for accurately and precisely measuring CBR data, involving improved (passive) dosing, sampling, and processing of organisms. The chemicals 1,2,4-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 2,3,4-trichloroaniline, 2,3,5,6-tetrachloroaniline, 4-chloro-3-methylphenol, pentylbenzene, pyrene, and bromophos-methyl were tested on Lumbriculus variegatus (California blackworm), Hyalella azteca (scud), and Poecilia reticulata (guppy), which yielded a high-quality database of 348 individual CBR values. Medians of CBR values ranged from 2.1 to 16.1 mmol/kg wet weight (ww) within all combinations of chemicals and species, except for the insecticide bromophos-methyl, for which the median was 1.3 mmol/kg ww. The new database thus covers about one log unit, which is considerably less than in existing databases. Medians differed maximally by a factor of 8.4 between the 7 chemicals but within one species, and by a factor of 2.6 between the three species but for individual chemicals. Accounting for the chemicals' internal distribution to different partitioning domains and relating effects to estimated concentrations in the target compartment (i.e., membrane lipids) was expected to but did not decrease the overall variability, likely because the surrogate partition coefficients for membrane lipid, storage lipid, protein, and carbohydrate that were used as input parameters did not sufficiently represent the actual partitioning processes. The results of this study demonstrate that a well-designed test setup can produce CBR data that are highly uniform beyond chemical and biological diversity.
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Affiliation(s)
- Stephan A van der Heijden
- Institute for Risk Assessment Sciences, Utrecht University , Yalelaan 104, 3584 CM Utrecht, The Netherlands
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25
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Padilla-Chavarría HI, Guizado TRC, Pimentel AS. Molecular dynamics of dibenz[a,h]anthracene and its metabolite interacting with lung surfactant phospholipid bilayers. Phys Chem Chem Phys 2015. [DOI: 10.1039/c5cp01443c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Dibenz[a,h]anthracene and its metabolite may form aggregates, which have implications in the clearance process of the lung surfactant phospholipid bilayers.
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Affiliation(s)
- Helmut I. Padilla-Chavarría
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rua Marques de São Vicente
- Rio de Janeiro
- Brazil
| | - Teobaldo R. C. Guizado
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rua Marques de São Vicente
- Rio de Janeiro
- Brazil
| | - Andre S. Pimentel
- Departamento de Química
- Pontifícia Universidade Católica do Rio de Janeiro
- Rua Marques de São Vicente
- Rio de Janeiro
- Brazil
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26
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Arp HPH, Lundstedt S, Josefsson S, Cornelissen G, Enell A, Allard AS, Kleja DB. Native oxy-PAHs, N-PACs, and PAHs in historically contaminated soils from Sweden, Belgium, and France: their soil-porewater partitioning behavior, bioaccumulation in Enchytraeus crypticus, and bioavailability. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:11187-95. [PMID: 25216345 DOI: 10.1021/es5034469] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Soil quality standards are based on partitioning and toxicity data for laboratory-spiked reference soils, instead of real world, historically contaminated soils, which would be more representative. Here 21 diverse historically contaminated soils from Sweden, Belgium, and France were obtained, and the soil-porewater partitioning along with the bioaccumulation in exposed worms (Enchytraeus crypticus) of native polycyclic aromatic compounds (PACs) were quantified. The native PACs investigated were polycyclic aromatic hydrocarbons (PAHs) and, for the first time to be included in such a study, oxygenated-PAHs (oxy-PAHs) and nitrogen containing heterocyclic PACs (N-PACs). The passive sampler polyoxymethylene (POM) was used to measure the equilibrium freely dissolved porewater concentration, Cpw, of all PACs. The obtained organic carbon normalized partitioning coefficients, KTOC, show that sorption of these native PACs is much stronger than observed in laboratory-spiked soils (typically by factors 10 to 100), which has been reported previously for PAHs but here for the first time for oxy-PAHs and N-PACs. A recently developed KTOC model for historically contaminated sediments predicted the 597 unique, native KTOC values in this study within a factor 30 for 100% of the data and a factor 3 for 58% of the data, without calibration. This model assumes that TOC in pyrogenic-impacted areas sorbs similarly to coal tar, rather than octanol as typically assumed. Black carbon (BC) inclusive partitioning models exhibited substantially poorer performance. Regarding bioaccumulation, Cpw combined with liposome-water partition coefficients corresponded better with measured worm lipid concentrations, Clipid (within a factor 10 for 85% of all PACs and soils), than Cpw combined with octanol-water partition coefficients (within a factor 10 for 76% of all PACs and soils). E. crypticus mortality and reproducibility were also quantified. No enhanced mortality was observed in the 21 historically contaminated soils despite expectations from PAH spiked reference soils. Worm reproducibility weakly correlated to Clipid of PACs, though the contributing influence of metal concentrations and soil texture could not be taken into account. The good agreement of POM-derived Cpw with independent soil and lipid partitioning models further supports that soil risk assessments would improve by accounting for bioavailability. Strategies for including bioavailability in soil risk assessment are presented.
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Affiliation(s)
- Hans Peter H Arp
- Norwegian Geotechnical Institute (NGI), P.O. Box 3930, Ullevål Stadion, N-0806 Oslo, Norway
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Jakobtorweihen S, Zuniga AC, Ingram T, Gerlach T, Keil FJ, Smirnova I. Predicting solute partitioning in lipid bilayers: Free energies and partition coefficients from molecular dynamics simulations and COSMOmic. J Chem Phys 2014; 141:045102. [DOI: 10.1063/1.4890877] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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28
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Paloncýová M, Fabre G, DeVane RH, Trouillas P, Berka K, Otyepka M. Benchmarking of Force Fields for Molecule–Membrane Interactions. J Chem Theory Comput 2014; 10:4143-51. [DOI: 10.1021/ct500419b] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Markéta Paloncýová
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacký University Olomouc, tř.
17 Listopadu 12, 771 46 Olomouc, Czech Republic
| | - Gabin Fabre
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacký University Olomouc, tř.
17 Listopadu 12, 771 46 Olomouc, Czech Republic
- LCSN
EA1069, Faculté de Pharmacie, Université de Limoges, 2 Rue de
Docteur Marcland, 87025 Limoges Cedex, France
| | - Russell H. DeVane
- Corporate Modeling and
Simulation, Procter and Gamble, 8611
Beckett Road, West Chester, Ohio 45069, United States
| | - Patrick Trouillas
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacký University Olomouc, tř.
17 Listopadu 12, 771 46 Olomouc, Czech Republic
- INSERM
UMR-S850, Faculté de Pharmacie, Université de Limoges, 2 Rue du
Docteur Marcland, 87025 Limoges Cedex, France
- Laboratoire
de Chimie des Matériaux Nouveaux, Université de Mons, Place du Parc 20, B-7000 Mons, Belgium
| | - Karel Berka
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacký University Olomouc, tř.
17 Listopadu 12, 771 46 Olomouc, Czech Republic
| | - Michal Otyepka
- Regional
Centre of Advanced Technologies and Materials, Department of Physical
Chemistry, Faculty of Science, Palacký University Olomouc, tř.
17 Listopadu 12, 771 46 Olomouc, Czech Republic
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29
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Quinn CL, van der Heijden SA, Wania F, Jonker MTO. Partitioning of polychlorinated biphenyls into human cells and adipose tissues: evaluation of octanol, triolein, and liposomes as surrogates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:5920-8. [PMID: 24806981 DOI: 10.1021/es500090x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Whereas octanol, triacylglycerides, and liposomes have all been proposed as surrogates for measuring the affinity of hydrophobic organic contaminants to human lipids, no comparative evaluation of their suitability exists. Here we conducted batch sorption experiments with polyoxymethylene passive samplers to determine the partition coefficients at 37 °C of 18 polychlorinated biphenyls (PCBs) from water into (i) triolein (Ktriolein/water), (ii) eight types of liposomes (Kliposome/water), (iii) human abdominal fat tissues (KAFT/water) from seven individuals, and (iv) human MCF-7 cells cultured in vitro (Kcell/water). Differences between KAFT/water among individuals and between Kliposome/water among liposome types were very small and not correlated to structural attributes of the PCBs. Similarly, the length and degree of saturation of the phospholipid carbon chains, the headgroup, and the composition of the liposome did not affect the partitioning of PCBs into the studied liposomes. Whereas Kliposome/water values were similar to literature values of Koctanol/water adjusted to 37 °C, they both were lower than KAFT/water and Kcell/water by a factor of 3 on average. Partitioning of PCBs into triolein on the other hand closely mimicked that into human lipids, for which triolein is thus a better surrogate than either octanol or liposomes. Previously published polyparameter linear free energy relationships for partitioning from water into storage lipids and liposomes predicted the measured partition coefficients with a root-mean-square error of less than 0.15 log units, if the chosen equations and solute descriptors do not allow chlorine substitution in the ortho-position to influence the prediction. By guiding the selection of (i) a surrogate for the experimental determination and (ii) a method for the prediction of partitioning into human lipids, this study contributes to a better assessment of hydrophobic organic contaminant bioaccumulation in humans.
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Affiliation(s)
- Cristina L Quinn
- Institute for Risk Assessment Sciences, Utrecht University , P.O. Box 80177, 3508 TD Utrecht, The Netherlands
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Zhao J, Wang Z, Ghosh S, Xing B. Phenanthrene binding by humic acid-protein complexes as studied by passive dosing technique. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 184:145-153. [PMID: 24047551 DOI: 10.1016/j.envpol.2013.08.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 08/09/2013] [Accepted: 08/12/2013] [Indexed: 06/02/2023]
Abstract
This work investigated the binding behavior of phenanthrene by humic acids (HA-2 and HA-5), proteins (bovine serum albumin (BSA)), lysozyme and pepsin), and their complexes using a passive dosing technique. All sorption isotherms were fitted well with Freundlich model and the binding capability followed an order of HA-5 > HA-2 > BSA > pepsin > lysozyme. In NaCl solution, phenanthrene binding to HA-BSA complexes was much higher than the sum of binding to individual HA and BSA, while there was no enhancement for HA-pepsin. Positively charged lysozyme slightly lowered phenanthrene binding on both HAs due to strong aggregation of HA-lysozyme complexes, leading to reduction in the number of binding sites. The binding enhancement by HA-BSA was observed under all tested ion species and ionic strengths. This enhancement can be explained by unfolding of protein, reduction of aggregate size and formation of HA-BSA complexes with favorable conformations for binding phenanthrene.
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Affiliation(s)
- Jian Zhao
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA
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31
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Lee SY, Kang HJ, Kwon JH. Toxicity cutoff of aromatic hydrocarbons for luminescence inhibition of Vibrio fischeri. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 94:116-122. [PMID: 23731864 DOI: 10.1016/j.ecoenv.2013.05.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 05/04/2013] [Accepted: 05/06/2013] [Indexed: 06/02/2023]
Abstract
Effects of individual petroleum hydrocarbons on the luminescence inhibition of Vibrio fischeri were evaluated according to a standard protocol to develop a quantitative structure-activity relationship and identify the apparent toxicity cutoff. Eighteen aromatic hydrocarbons, including benzene and its derivatives and polycyclic aromatic hydrocarbons (PAHs), were chosen as model compounds with their log K(ow) values between 2.7 and 6.4. The obtained values of 50 percent luminescence inhibition (EC50) showed a good linear correlation with log K(ow) up to ~5. However, toxic effects were not observed for more hydrophobic chemicals with log K(ow) value >5. The calculated chemical activities that caused EC50 were mostly between 0.01 and 0.1. This agrees with an earlier hypothesis concerning a chemical activity resulting the critical membrane concentration of aromatic hydrocarbons. The highest chemical activities for aromatic hydrocarbons with log K(ow) value >5 or melting point >100°C are <0.01 when they are spiked at their water solubility level according to the standard test protocol; this occurs for two primary reasons: (1) partitioning between organism and the test solution and (2) decreasing fugacity ratio with increasing melting point. Accordingly, luminescence inhibition by petroleum hydrocarbons is well explained by the baseline toxicity model. However, the apparent toxicity cutoff observed for single chemicals is not necessarily valid in a complex mixture, because baseline toxicity is regarded concentration additive.
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Affiliation(s)
- So-Young Lee
- Department of Environmental Engineering, Ajou University, Yeongtong-gu, Suwon, Republic of Korea
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32
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Kuo DTF, Di Toro DM. Biotransformation model of neutral and weakly polar organic compounds in fish incorporating internal partitioning. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2013; 32:1873-1881. [PMID: 23625748 DOI: 10.1002/etc.2259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 03/29/2013] [Accepted: 04/22/2013] [Indexed: 06/02/2023]
Abstract
A model for whole-body in vivo biotransformation of neutral and weakly polar organic chemicals in fish is presented. It considers internal chemical partitioning and uses Abraham solvation parameters as reactivity descriptors. It assumes that only chemicals freely dissolved in the body fluid may bind with enzymes and subsequently undergo biotransformation reactions. Consequently, the whole-body biotransformation rate of a chemical is retarded by the extent of its distribution in different biological compartments. Using a randomly generated training set (n = 64), the biotransformation model is found to be: log (HLφfish ) = 2.2 (±0.3)B - 2.1 (±0.2)V - 0.6 (±0.3) (root mean square error of prediction [RMSE] = 0.71), where HL is the whole-body biotransformation half-life in days, φfish is the freely dissolved fraction in body fluid, and B and V are the chemical's H-bond acceptance capacity and molecular volume. Abraham-type linear free energy equations were also developed for lipid-water (Klipidw ) and protein-water (Kprotw ) partition coefficients needed for the computation of φfish from independent determinations. These were found to be 1) log Klipidw = 0.77E - 1.10S - 0.47A - 3.52B + 3.37V + 0.84 (in Lwat /kglipid ; n = 248, RMSE = 0.57) and 2) log Kprotw = 0.74E - 0.37S - 0.13A - 1.37B + 1.06V - 0.88 (in Lwat /kgprot ; n = 69, RMSE = 0.38), where E, S, and A quantify dispersive/polarization, dipolar, and H-bond-donating interactions, respectively. The biotransformation model performs well in the validation of HL (n = 424, RMSE = 0.71). The predicted rate constants do not exceed the transport limit due to circulatory flow. Furthermore, the model adequately captures variation in biotransformation rate between chemicals with varying log octanol-water partitioning coefficient, B, and V and exhibits high degree of independence from the choice of training chemicals. The present study suggests a new framework for modeling chemical reactivity in biological systems.
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Affiliation(s)
- Dave T F Kuo
- Civil and Environmental Engineering Department, University of Delaware, Newark, Delaware, USA.
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Witt G, Lang SC, Ullmann D, Schaffrath G, Schulz-Bull D, Mayer P. Passive equilibrium sampler for in situ measurements of freely dissolved concentrations of hydrophobic organic chemicals in sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:7830-7839. [PMID: 23819657 DOI: 10.1021/es400395t] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this study, an equilibrium passive sampling device is introduced that facilitates the in situ measurement of hydrophobic organic chemicals bioavailability in sediments in terms of freely dissolved concentrations. The new field sampler allows SPME fibers and silicone hollow fibers to be immersed and equilibrated in situ, whereas an automated liner exchanger (ALEX) facilitates the quantitative transfer of analytes to the GC without the use of extraction solvents. The sampler was developed for environmental monitoring as follows: (1) It is of very solid construction and can be reused practically ad infinitum. (2) Fibers with varying surface to volume ratios can be exposed in parallel in order to confirm that equilibrium was reached between sampler and sediment. (3) The equilibrium times allow a temporal resolution that is suited for monitoring of both long-term trends and seasonal effects. The automated thermal desorption reduced sample treatment to a minimum and ensured cost- and time-efficient measurements while minimizing potential error sources after the sampling. The sampler is applicable in a multitude of aquatic environments, especially where currents are low and sediments are muddy and well-mixed, e.g. by bioturbation. Examples for such environments are mud flats, harbor basins, river banks, and lakes.
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Affiliation(s)
- Gesine Witt
- University of Applied Sciences Hamburg , Lohbrügger Kirchstraße 65, 21033 Hamburg, Germany.
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Schmidt SN, Holmstrup M, Smith KEC, Mayer P. Passive dosing of polycyclic aromatic hydrocarbon (PAH) mixtures to terrestrial springtails: linking mixture toxicity to chemical activities, equilibrium lipid concentrations, and toxic units. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:7020-7027. [PMID: 23473585 DOI: 10.1021/es3047813] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A 7-day mixture toxicity experiment with the terrestrial springtail Folsomia candida was conducted, and the effects were linked to three different mixture exposure parameters. Passive dosing from silicone was applied to tightly control exposure levels and compositions of 12 mixture treatments, containing the polycyclic aromatic hydrocarbons (PAHs) naphthalene, phenanthrene, and pyrene. Springtail lethality was then linked to sum chemical activities (∑a), sum equilibrium lipid concentrations (∑C(lipid eq.)), and sum toxic units (∑TU). In each case, the effects of all 12 mixture treatments could be fitted to one sigmoidal exposure-response relationship. The effective lethal chemical activity (La50) of 0.027 was well within the expected range for baseline toxicity of 0.01-0.1. Linking the effects to the lipid-based exposure parameter yielded an effective lethal concentration (LC(lipid eq 50)) of 133 mmol kg(-1) lipid in good correspondence with the lethal membrane burden for baseline toxicity (40-160 mmol kg(-1) lipid). Finally, the effective lethal toxic unit (LTU50) of 1.20 was rather close to the expected value of 1. Altogether, passive dosing provided tightly controlled mixture exposure in terms of both level and composition, while ∑a, ∑C(lipid eq.), and ∑TU allowed baseline toxicity to be linked to mixture exposure.
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Affiliation(s)
- Stine N Schmidt
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, PO Box 358, DK-4000 Roskilde, Denmark.
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Jakobtorweihen S, Ingram T, Smirnova I. Combination of COSMOmic and molecular dynamics simulations for the calculation of membrane-water partition coefficients. J Comput Chem 2013; 34:1332-40. [DOI: 10.1002/jcc.23262] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 02/01/2013] [Accepted: 02/03/2013] [Indexed: 12/28/2022]
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Smith KEC, Schmidt SN, Dom N, Blust R, Holmstrup M, Mayer P. Baseline toxic mixtures of non-toxic chemicals: "solubility addition" increases exposure for solid hydrophobic chemicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:2026-2033. [PMID: 23331084 DOI: 10.1021/es3040472] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This study addresses the question whether hydrophobic organic chemicals exerting no toxicity at their solubility limit (saturation) can form a toxic mixture. Spiking methods generally do not allow testing exactly at saturation without introducing microcrystals. Passive dosing was thus applied to test the acute toxicity of several high melting point PAHs and their mixtures at the respective saturation levels to aquatic and terrestrial invertebrates. With the aquatic Daphnia magna, anthracene, chrysene, and benzo(a)pyrene resulted in no or limited acute toxicity (0-20%), whereas binary and tertiary mixtures of these resulted in significant acute toxicity (70-88%). Toxicity of PAHs and their mixtures could be fitted with one (sum) chemical activity-response curve in accordance with a similar mode of toxic action (i.e., concentration addition). The effective chemical activity (Ea-50) of 0.029 and the effective concentration on a lipid basis (EC(lipid, eq.)-50) of 95.7 mM were well within the range for baseline toxicity. Similar mixtures showed less toxicity to the terrestrial Folsomia candida due to steady-state body-burdens being below equilibrium partitioning levels. The results of the present study raise questions about the focus of risk assessment schemes and toxicity testing guidelines on individual substances, since apparently non-toxic chemicals might become toxic in a mixture.
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Affiliation(s)
- Kilian E C Smith
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, PO Box 358, 4000 Roskilde, Denmark
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Endo S, Mewburn B, Escher BI. Liposome and protein-water partitioning of polybrominated diphenyl ethers (PBDEs). CHEMOSPHERE 2013; 90:505-511. [PMID: 22955047 DOI: 10.1016/j.chemosphere.2012.07.069] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 06/07/2012] [Accepted: 07/24/2012] [Indexed: 06/01/2023]
Abstract
Bioaccumulation of polybrominated diphenyl ethers (PBDEs) in marine and terrestrial organisms is of great environmental concern. Understanding the partitioning of PBDEs to biological phases is crucial for elucidating their bioaccumulation behavior. In this study, partitioning coefficients of PBDEs from water to phospholipid liposomes (K(lipw)) and to bovine serum albumin (BSA) (K(BSAw)) were measured using a polymer depletion method. K(lipw) values measured in two laboratories are in an excellent agreement (within 0.14 log units), indicating a high method repeatability. The values of log K(lipw) and log K(BSAw) are in the range of 6.3-8.2 and 5.1-7.0, respectively, representing the highest of these partition coefficients measured to date. Log K(lipw) values for PBDEs are similar to the log of the octanol-water partition coefficients (K(ow)) (log K(lipw)-log K(ow)=-0.06±0.23; mean±SD of 7 congeners), consistent with the data of chlorobenzenes and polychlorinated biphenyls (PCBs) reported in the literature. No hydrophobicity cutoff was observed for partitioning to the liposome membrane. Log K(BSAw) values for PBDEs increase linearly with log K(ow) and do not follow the non-linear trend observed for polycyclic aromatic hydrocarbons (PAHs). This difference between PBDEs and PAHs suggests specific binding mechanisms to serum albumin even for hydrophobic compounds.
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Affiliation(s)
- Satoshi Endo
- Department of Analytical Environmental Chemistry, UFZ - Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany.
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Tcaciuc AP, Nelson RK, Reddy CM, Gschwend PM. Estimating phospholipid membrane-water partition coefficients using comprehensive two-dimensional gas chromatography. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:3449-3456. [PMID: 22397714 DOI: 10.1021/es203792e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Recent studies have shown that membrane-water partition coefficients of organic chemicals can be used to predict bioaccumulation and type I narcosis toxicity more accurately than the traditional K(OW)-based approach. In this paper, we demonstrate how comprehensive two-dimensional gas chromatography (GC × GC) can be used to estimate such membrane-water partition coefficients (K(PLW)s), focusing in particular on phosphatidyl choline based lipids. This method performed well for a set of 38 compounds, including polycyclic aromatic hydrocarbons, polychlorinated benzenes and biphenyls, and substituted benzenes including some phenols and anilines. The average difference between the estimated and the measured log K(PLW) values of 0.47 log units is smaller than in the case of a log K(OW) correlation approach but larger than seen using a polyparameter linear free energy relationship based approach. However, the GC × GC based method presents the advantage that it can be applied to mixtures of chemicals that are not completely identified, such as petroleum hydrocarbon mixtures. At the same time, our application of the GC × GC method suffered larger errors when applied to certain hydrogen bonding compounds due to the inability of the GC × GC capillary columns phases that we used to interact with analytes via hydrogen bond donation/electron acceptance.
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Affiliation(s)
- A Patricia Tcaciuc
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
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van der Heijden SA, Jonker MTO. Intra- and interspecies variation in bioconcentration potential of polychlorinated biphenyls: are all lipids equal? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:10408-10414. [PMID: 22054258 DOI: 10.1021/es2022158] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The variation among bioconcentration factors (BCFs) available in the literature is commonly ascribed to experimental parameters and metabolic capacity. Though bioconcentration is generally considered to be governed by partitioning processes and therefore to depend on the composition of the partition phases, the effect of lipid composition on BCFs measured for hydrophobic organic chemicals has largely escaped attention. The reason may be that the effect cannot easily be studied separately in a conventional BCF test setup and that any subtle effects will often be obscured by the variation normally observed when working with living organisms. In the present study, this variation was circumvented by substituting biota with biological homogenates, which allowed measuring chemical partitioning in a fashion that has proved successful for many other environmental matrixes (e.g., sediments, soils, carbonaceous materials). The appropriateness of using a homogenate as a representation of the organism from which it was derived was demonstrated by a good agreement between homogenate-water partition coefficients (or necroconcentration factors; NCFs) and actual BCFs for PCBs and aquatic worms. Subsequent experiments focused on the intra- and interspecies differences in lipid-normalized NCFs. Intraspecies variation was studied for aquatic worms and sticklebacks, which were acclimatized at different temperatures (5-24 °C), whereas interspecies variation was investigated by determining NCFs for eight different aquatic species. Although temperature-induced intraspecies differences were subtle (<0.16 log units), interspecies differences among lipid-normalized NCFs were as high as 0.9 log units, with homogenates of "simple" organisms showing a lower sorption capacity than those of the more "complex" species. These results suggest that the variation observed in the literature BCFs may partly be caused by differences in lipid composition and contest the usefulness of the common practice of applying generic BCFs in risk assessment of chemicals.
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Affiliation(s)
- Stephan A van der Heijden
- Institute for Risk Assessment Sciences, Utrecht University, P.O. Box 80177, 3508 TD Utrecht, The Netherlands.
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Hawthorne SB, Jonker MTO, van der Heijden SA, Grabanski CB, Azzolina NA, Miller DJ. Measuring Picogram per Liter Concentrations of Freely Dissolved Parent and Alkyl PAHs (PAH-34), Using Passive Sampling with Polyoxymethylene. Anal Chem 2011; 83:6754-61. [DOI: 10.1021/ac201411v] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Steven B. Hawthorne
- Energy and Environmental Research Center (EERC), University of North Dakota, Box 9018, Grand Forks, North Dakota 58202, United States
| | - Michiel T. O. Jonker
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80177, 3508 TD Utrecht, The Netherlands
| | - Stephan A. van der Heijden
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, P.O. Box 80177, 3508 TD Utrecht, The Netherlands
| | - Carol B. Grabanski
- Energy and Environmental Research Center (EERC), University of North Dakota, Box 9018, Grand Forks, North Dakota 58202, United States
| | - Nicholas A. Azzolina
- Department of Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - David J. Miller
- Energy and Environmental Research Center (EERC), University of North Dakota, Box 9018, Grand Forks, North Dakota 58202, United States
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Endo S, Escher BI, Goss KU. Capacities of membrane lipids to accumulate neutral organic chemicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:5912-21. [PMID: 21671592 DOI: 10.1021/es200855w] [Citation(s) in RCA: 220] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Lipids have been considered as the predominant components for bioaccumulation of organic chemicals. However, differences in accumulation properties between different types of lipid (e.g., storage and membrane lipids) have rarely been considered. Moreover, in view of toxic effects on organisms, chemical accumulation specifically in biological membranes is of particular importance. In this review article, partition coefficients of 240 neutral organic compounds between liposomes (phospholipid membrane vesicles) and water (K(lipw)), reported in the literature or measured additionally for this work, were evaluated. Values of log K(lipw) and log K(ow) (octanol-water partition coefficients) differ by 0.4 on average. Polyparameter linear free energy relationships (PP-LFERs) can describe the log K(lipw) data even better (standard deviations = 0.28-0.31) than the log K(ow) model. Recent experimental data for highly hydrophobic compounds fit well to the PP-LFERs and do not indicate the existence of a previously postulated "hydrophobicity cutoff". Predictive approaches based only on the molecular structure (KOWWIN, SPARC, COSMOthermX, COSMOmic) were also evaluated for K(lipw) prediction. The PP-LFERs revealed that partition coefficients into membrane lipids can be two log units higher than those into storage lipids for H-bond donor compounds, suggesting that distinguishing between the two lipids is necessary to account for the bioaccumulation of these compounds, and that tissues rich in membrane lipids (e.g., kidneys, liver) instead of fat tissue can be the primary phase for accumulation.
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Affiliation(s)
- Satoshi Endo
- Department of Analytical Environmental Chemistry, UFZ - Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany.
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Muijs B, Jonker MTO. Assessing the bioavailability of complex petroleum hydrocarbon mixtures in sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:3554-3561. [PMID: 21417446 DOI: 10.1021/es103855a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Several experimental methods have been developed to assess the bioavailability of individual organic compounds. So far none of them has however been applied to complex mixtures, such as oil (petroleum hydrocarbons), which is an ubiquitous pollutant. In the present study, we tested the potential of five of these experimental methods and that of a model approach to predict bioaccumulation of oil in the aquatic worm Lumbriculus variegatus exposed to 14 field-contaminated sediments. Actual and predicted bioaccumulation were compared in terms of both total bioaccumulative petroleum hydrocarbon concentrations and the relative distribution pattern of separate boiling point fractions (hydrocarbon blocks). None of the experimental methods was able to directly assess bioaccumulation in L. variegatus and correction factors were needed to match predicted and actual concentrations. These factors appeared concentration-dependent for solid phase micro extraction (SPME) and extractions with Tenax and cyclodextrin, most probably due to artifacts. Moreover, the hydrocarbon block pattern produced by these methods considerably differed from the pattern observed for worms; an additional reason for disqualification also applying to headspace-SPME. In contrast, the pattern produced by polyoxymethylene solid phase extraction (POM-SPE) closely mimicked the worm pattern and a sediment, hydrocarbon block, and concentration-independent correction factor (17) could be derived, based on which actual bioaccumulation could be predicted within a factor of 3. Finally, the model predicted bioaccumulation directly within a factor of 2. The accompanying hydrocarbon block pattern however deviated significantly more from the worm pattern than the POM-SPE pattern did. We therefore conclude that POM-SPE may be the overall best approach for predicting bioaccumulation of complex hydrocarbon mixtures in aquatic worms, all the more since an experimental approach will implicitly capture all factors determining bioavailability, which may prove difficult through a modeling approach.
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Affiliation(s)
- Barry Muijs
- Institute for Risk Assessment Sciences, Utrecht University , P.O. Box 80177, 3508 TD Utrecht, The Netherlands
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Määenpää K, Leppänen MT, Reichenberg F, Figueiredo K, Mayer P. Equilibrium sampling of persistent and bioaccumulative compounds in soil and sediment: comparison of two approaches to determine equilibrium partitioning concentrations in lipids. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:1041-7. [PMID: 21174455 DOI: 10.1021/es1029969] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The equilibrium sampling in silicone is increasingly applied to measure freely dissolved concentrations and chemical activities within bioaccumulation research of hydrophobic organic chemicals. Two equilibrium methods were applied to PCB-contaminated soil and sediment, and directly calibrated with respect to equilibrium partitioning concentrations in lipids (C(lipid,partitioning)): (i) Solid phase microextraction in the headspace above the sample (HS-SPME) required optimization for its application to PCBs, and it was calibrated above external partitioning standards in olive oil. (ii) Equilibrium sampling with internally coated glass jars with varying thicknesses of silicone (PDMS) resulted in proportionality between coating and analyte mass, which confirmed several validity criteria. C(lipid,partitioning) was here determined as product of PDMS concentration and PDMS to lipid partition ratio. The results of the two methods were in good agreement and thus validated each other. Finally, the coated glass jar method was applied to field sediment containing invertebrates, which lead to C(lipid,partitioning) that were about two times higher than measured lipid-normalized concentrations in the organisms. Temperature differences and animal lipid structure were discussed as possible reasons for this discrepancy. Both methods combine high analytical performance, reduced equilibration times and new calibration possibilities, which makes them suited for bioaccumulation research and environmental monitoring.
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Affiliation(s)
- Kimmo Määenpää
- Department of Biology, University of Eastern Finland, P.O. Box 111, FIN-80101 Joensuu, Finland.
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Endo S, Droge STJ, Goss KU. Polyparameter Linear Free Energy Models for Polyacrylate Fiber−Water Partition Coefficients to Evaluate the Efficiency of Solid-Phase Microextraction. Anal Chem 2011; 83:1394-400. [DOI: 10.1021/ac102868e] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Satoshi Endo
- Department of Analytical Environmental Chemistry, UFZ − Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
| | - Steven T. J. Droge
- Department of Analytical Environmental Chemistry, UFZ − Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Yalelaan 2, 3584 CM Utrecht, The Netherlands
| | - Kai-Uwe Goss
- Department of Analytical Environmental Chemistry, UFZ − Helmholtz Centre for Environmental Research, Permoserstrasse 15, D-04318 Leipzig, Germany
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Ruus A, Bøyum O, Grung M, Næs K. Bioavailability of PAHs in aluminum smelter affected sediments: evaluation through assessment of pore water concentrations and in vivo bioaccumulation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2010; 44:9291-9297. [PMID: 21077669 DOI: 10.1021/es103020e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) from coal tar pitch polluted sediments was predicted by (1) a generic approach based on organic carbon-water partitioning and Gibbs linear free energy relationship (between K(OW) and K(OC)), and (2) measurements of freely dissolved concentrations of PAHs in the sediment pore water, using passive samplers and solid phase extraction. Results from these predictions were compared with those from in vivo bioaccumulation experiments using Nereis diversicolor (Polychaeta), Hinia reticulata (Gastropoda), and Nuculoma tenuis (Bivalvia). Measured sediment/water partition coefficients were higher than predicted by the generic approach. Furthermore, predicted biota-to-sediment accumulation factors (BSAFs) derived from measured pore water concentrations were more in agreement with the bioaccumulation observed for two of the three species. Discrepancies associated with the third species (N. tenuis) were likely a result of particles remaining in the intestine (as shown by microscopic evaluation). These results indicate the importance of conducting site-specific evaluations of pore water concentrations and/or bioaccumulation studies by direct measurements to accurately provide a basis for risk assessment and remediation plans. The importance of knowledge regarding specific characteristics of model organisms is emphasized.
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Affiliation(s)
- Anders Ruus
- Norwegian Institute for Water Research, Gaustadalléen 21, 0349 Oslo, Norway.
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Ojogun V, Vyas SM, Lehmler HJ, Knutson BL. Partitioning of homologous nicotinic acid ester prodrugs (nicotinates) into dipalmitoylphosphatidylcholine (DPPC) membrane bilayers. Colloids Surf B Biointerfaces 2010; 78:75-84. [PMID: 20227859 PMCID: PMC2873030 DOI: 10.1016/j.colsurfb.2010.02.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 02/09/2010] [Accepted: 02/11/2010] [Indexed: 11/30/2022]
Abstract
The partitioning behavior of a series of perhydrocarbon nicotinic acid esters (nicotinates) between aqueous solution and dipalmitoylphosphatidylcholine (DPPC) membrane bilayers is investigated as a function of increasing alkyl chain length. The hydrocarbon nicotinates represent putative prodrugs, derivatives of the polar drug nicotinic acid, whose functionalization provides the hydrophobic character necessary for pulmonary delivery in a hydrophobic, fluorocarbon solvent, such as perfluorooctyl bromide. Independent techniques of differential scanning calorimetry and 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence anisotropy measurements are used to analyze the thermotropic phase behavior and lipid bilayer fluidity as a function of nicotinate concentration. At increasing concentrations of nicotinates over the DPPC mole fraction range examined (X(DPPC)=0.6-1.0), all the nicotinates (ethyl (C2H5); butyl (C4H9); hexyl (C6H13); and octyl (C8H17)) partition into the lipid bilayer at sufficient levels to eliminate the pretransition, and decrease and broaden the gel to fluid phase transition temperature. The concentration at which these effects occur is chain length-dependent; the shortest chain nicotinate, C2H5, elicits the least dramatic response. Similarly, the DPH anisotropy results demonstrate an alteration of the bilayer organization in the liposomes as a consequence of the chain length-dependent partitioning of the nicotinates into DPPC bilayers. The membrane partition coefficients (logarithm values), determined from the depressed bilayer phase transition temperatures, increase from 2.18 for C2H5 to 5.25 for C8H17. The DPPC membrane/water partitioning of the perhydrocarbon nicotinate series correlates with trends in the octanol/water partitioning of these solutes, suggesting that their incorporation into the bilayer is driven by increasing hydrophobicity.
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Affiliation(s)
- Vivian Ojogun
- Department of Chemical and Materials Engineering 177 Anderson Hall, University of Kentucky, Lexington, KY 40506-0046
| | - Sandhya M. Vyas
- Department of Occupational and Environmental Health, 100 Oakdale Campus, #124 IREH, University of Iowa, Iowa City, IA 52242-5000
| | - Hans-Joachim Lehmler
- Department of Occupational and Environmental Health, 100 Oakdale Campus, #124 IREH, University of Iowa, Iowa City, IA 52242-5000
| | - Barbara L Knutson
- Department of Chemical and Materials Engineering 177 Anderson Hall, University of Kentucky, Lexington, KY 40506-0046
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Qin Z, Mok S, Ouyang G, Dixon DG, Pawliszyn J. Partitioning and accumulation rates of polycyclic aromatic hydrocarbons into polydimethylsiloxane thin films and black worms from aqueous samples. Anal Chim Acta 2010; 667:71-6. [DOI: 10.1016/j.aca.2010.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2010] [Revised: 03/31/2010] [Accepted: 04/01/2010] [Indexed: 10/19/2022]
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