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Chen Y, Yu Y, Wang S, Han J, Fan M, Zhao Y, Qiu J, Yang X, Zhu F, Ouyang G. Molecularly imprinted polymer sheathed mesoporous silica tube as SPME fiber coating for determination of tobacco-specific nitrosamines in water. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 906:167655. [PMID: 37806576 DOI: 10.1016/j.scitotenv.2023.167655] [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: 07/30/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023]
Abstract
Tobacco-specific nitrosamines (TSNAs) are probably carcinogenic disinfection byproducts eliciting health risk concerns. The determination and surveillance of TSNAs in water is still cumbersome due to the lack of advanced sample preparation methods. Herein, we prepared a solid phase microextraction (SPME) fiber coated with the molecularly imprinted polymer (MIP) sheathed mesoporous silica tube (MST) composite material, and developed a highly efficient, selective, and sensitive method for the determination of five TSNAs in water. Benefiting from the TSNAs-specific recognition of MIP and the increased specific surface area derived from MST, the MIP@MST fiber exhibited excellent extraction performance for TSNAs, which was much superior to the commercially available SPME fibers. By coupling to high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), the outstanding analytical merits such as low method detection limits (ranging 0.1-6.7 ng L-1) and good reproducibility (intra-fiber and inter-fiber relative standard deviations ranging 4.1 %-11.6 % and 3.5 %-12.2 %, respectively) were achieved with the consumption of 8 mL water sample and 100 μL methanol solvent in 50 min. The feasibility of the SPME-HPLC-MS/MS method was demonstrated in tap water and chloraminated source water, with relative recoveries for the five TSNAs ranging from 85.2 % to 108.5 %. In result, none of the TSNAs were found in the tap water samples, while 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-Butanol (NNAL) were detected in the chloraminated source water samples. The rapid and convenient SPME-HPLC-MS/MS method developed in this study offers a powerful tool for monitoring TSNAs in water.
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Affiliation(s)
- Yuemei Chen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Yang Yu
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Shaohan Wang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Jiajia Han
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Mengge Fan
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Yanping Zhao
- Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology, Guangdong Institute of Analysis (China National Analytical Center Guangzhou), Guangdong Academy of Sciences, Guangzhou 510070, China
| | - Junlang Qiu
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China.
| | - Xin Yang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China
| | - Fang Zhu
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China.
| | - Gangfeng Ouyang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry/KLGHEI of Environment and Energy Chemistry, School of Chemical Engineering and Technology, School of Environmental Science and Engineering, School of Chemistry, Institute of Green Chemistry and Molecular Engineering, Sun Yat-sen University, Guangzhou 510006, China; Chemistry College, Center of Advanced Analysis and Gene Sequencing, Zhengzhou University, Zhengzhou 450001, China; Guangdong Provincial Key Laboratory of Emergency Test for Dangerous Chemicals, Guangdong Provincial Key Laboratory of Chemical Measurement and Emergency Test Technology, Guangdong Institute of Analysis (China National Analytical Center Guangzhou), Guangdong Academy of Sciences, Guangzhou 510070, China
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Dang B, Jia W, Ma S, Zhang X, Huang Y, Huang W, Han D, Zhang K, Zhao F, Zhang Y, Xu Z. Characterization of a novel nornicotine-degrading strain Mycolicibacterium sp. SMGY-1XX from a nornicotine-degrading consortium and preliminary elucidation of its biodegradation pathway by multi-omics analysis. JOURNAL OF HAZARDOUS MATERIALS 2023; 457:131777. [PMID: 37290356 DOI: 10.1016/j.jhazmat.2023.131777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 05/14/2023] [Accepted: 06/02/2023] [Indexed: 06/10/2023]
Abstract
Nicotine and nornicotine are all toxic alkaloids involved in the formation of carcinogenic tobacco-specific nitrosamines. Microbes play an important role in removing these toxic alkaloids and their derivatives from tobacco-polluted environments. By now, microbial degradation of nicotine has been well studied. However, limited information is available on the microbial catabolism of nornicotine. In the present study, a nornicotine-degrading consortium was enriched from a river sediment sample and characterized by metagenomic sequencing using a combination of Illumina and Nanopore technologies. The metagenomic sequencing analysis demonstrated that Achromobacter, Azospirillum, Mycolicibacterium, Terrimonas, and Mycobacterium were the dominant genera in the nornicotine-degrading consortium. A total of 7 morphologically distinct bacterial strains were isolated from the nornicotine-degrading consortium. These 7 bacterial strains were characterized by whole genome sequencing and examined for their ability to degrade nornicotine. Based on a combination of 16 S rRNA gene similarity comparisons, 16 S rRNA gene-based phylogenetic analysis, and ANI analysis, the accurate taxonomies of these 7 isolated strains were identified. These 7 strains were identified as Mycolicibacterium sp. strain SMGY-1XX, Shinella yambaruensis strain SMGY-2XX, Sphingobacterium soli strain SMGY-3XX, Runella sp. strain SMGY-4XX, Chitinophagaceae sp. strain SMGY-5XX, Terrimonas sp. strain SMGY-6XX, Achromobacter sp. strain SMGY-8XX. Among these 7 strains, Mycolicibacterium sp. strain SMGY-1XX, which has not been reported previously to have the ability to degrade nornicotine or nicotine, was found to be capable of degrading nornicotine, nicotine as well as myosmine. The degradation intermediates of nornicotine and myosmine by Mycolicibacterium sp. strain SMGY-1XX were determined and the nornicotine degradation pathway in strain SMGY-1XX was proposed. Three novel intermediates, myosmine, pseudooxy-nornicotine, and γ-aminobutyrate, were identified during the nornicotine degradation process. Further, the most likely candidate genes responsible for nornicotine degradation in Mycolicibacterium sp. strain SMGY-1XX were identified by integrating genomic analysis, transcriptomic analysis, and proteomic analysis. The findings in this study will help to expand our understanding on the microbial catabolism of nornicotine and nicotine and provide new insights into the nornicotine degradation mechanism by consortia and pure culture, laying a foundation for the application of strain SMGY-1XX for the removal, biotransformation, or detoxification of nornicotine.
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Affiliation(s)
- Bingjun Dang
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China.
| | - Wei Jia
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Shuanglong Ma
- College of Resources and Environmental Sciences, Henan Agricultural University, Zhengzhou 450002, China
| | - Xiaoping Zhang
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China; Flavors and Fragrance Engineering & Technology Research Center of Henan Province, Zhengzhou 450002, China
| | - Yao Huang
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
| | - Wuxing Huang
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Dan Han
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Kai Zhang
- School of Geographic Sciences, Xinyang Normal University, Xinyang 464000, China
| | - Fanchong Zhao
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Yuwei Zhang
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China
| | - Zicheng Xu
- College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China.
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Zhang J, Liu X, Shi B, Yang Z, Luo Y, Xu T, Liu D, Jiang C, Du G, Lu N, Zhang C, Ma Y, Bai R, Zhou J. Investigation of exposure biomarkers in human plasma following differing levels of tobacco-specific N-nitrosamines and nicotine in cigarette smoke. ENVIRONMENTAL RESEARCH 2022; 214:113811. [PMID: 35835167 DOI: 10.1016/j.envres.2022.113811] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/28/2022] [Accepted: 06/30/2022] [Indexed: 06/15/2023]
Abstract
Tobacco-specific N-nitrosamines (TSNAs) are strong carcinogens widely found in tobacco products, environmental tobacco smoke, lake, and wastewater. The main objective of this study was to investigate the effects of cigarette smoke with different yields of TSNAs (NNK, NNN, NAT, NAB) and nicotine on the levels of biomarkers of exposure in smokers' plasma. Three hundred healthy volunteers were recruited comprising 60 smokers of each of 3 mg, 8 mg and 10 mg ISO tar yield cigarettes and 60 smokers who smoked 10 mg, 8 mg, and 3 mg for 14 days sequentially and 60 non-smokers. All study participants were male, aged from 21 to 45 years old, and were recruited from a same unit in Hebei, China. We measured the levels of NNAL, NAT, NNN, NAB and cotinine in plasma from 240 smokers and 60 non-smokers using a novel method established by online two-dimensional solid phase extraction-liquid chromatography-tandem mass spectrometry. The results showed that NNAL, NAT, NNN, NAB and cotinine in the plasma of smokers smoking cigarette with low TSNAs and nicotine were lower than that with high TSNAs and nicotine. When smokers switched from higher to lower TSNA yields of cigarettes, their plasma NNAL, NAT, NNN, NAB levels significantly decreased. The plasma concentrations of NNAL were significantly correlated with those of cotinine, NNN, NAT and NAB for smokers (p < 0.001). Similarly, the plasma concentrations of cotinine were significantly correlated with those of NNN, NAT and NAB for smokers (p < 0.001). The plasma NNAL, NAT, NNN, NAB and cotinine levels for smokers were significantly higher than those for non-smokers. These findings suggested that the total NNAL, NNN, NAT, NAB and cotinine in plasma were valid and reliable biomarkers for human exposure to TSNAs and nicotine.
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Affiliation(s)
- Jie Zhang
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Xingyu Liu
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Bing Shi
- Department of Cardiology, Beijing Military General Hospital, Beijing, China
| | - Zhendong Yang
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Yanbo Luo
- China National Tobacco Quality Supervision & Test Centre, Zhengzhou, China
| | - Tongguang Xu
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Deshui Liu
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Chengyong Jiang
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Guorong Du
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Nan Lu
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Chen Zhang
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Yanjun Ma
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Ruoshi Bai
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China
| | - Jun Zhou
- Beijing Third Class Tobacco Super Vision Station, Beijing, 101121, China.
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Najme R, Zhuang S, Qiu J, Lu Z. Identification and characterization of Nornicotine degrading strain Arthrobacter sp. NOR5. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 764:142894. [PMID: 33131868 DOI: 10.1016/j.scitotenv.2020.142894] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/26/2020] [Accepted: 10/01/2020] [Indexed: 06/11/2023]
Abstract
Nornicotine, the primary nicotine metabolite that is formed through demethylation of nicotine in the genus Nicotiana tabacum L. Nornicotine is not only a precursor of tobacco-specific nitrosamine N-nitrosonornicotine but also have detrimental effects to human health. Till now, information on the biotransformation of nornicotine is limited. Herein, we identified and characterized a bacterium Arthrobacter sp. strain NOR5, utilized nornicotine as the sole of carbon and energy source, and degraded 500 mg/L nornicotine completely within 60 h under the optimum conditions of pH 7.0 and 30 °C. In this study, we not only identified previously reported intermediate metabolites such as 6-OH-nornicotine, 6-OH-mysomine, 6-OH-pseudooxy-nornicotine (6HPONor) but also identified a new intermediate metabolite 2,6-di-OH-pseudooxy-nornicotine (2,6DHPONor) by UV spectroscopy and liquid chromatography coupled with time of flight mass spectrometry. About half of 6HPONor could be transformed into 2,6DHPONor that was identified as a novel catabolic intermediate of nornicotine. By the addition of an electron acceptor 2,6-dichlorophenolindophenol (DCIP), the cell-free extract exhibited inducible 6HPONor dehydrogenase activity at 179 ± 60 mU/mg that could convert 6HPONor to 2,6DHPONor. Our study demonstrated that Arthrobacter sp. strain NOR5 has a high potential to degrade the nornicotine completely.
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Affiliation(s)
- Rabia Najme
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou 310058, China; College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shulin Zhuang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jiguo Qiu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
| | - Zhenmei Lu
- MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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Qiu J, Zhang Y, Craven C, Liu Z, Gao Y, Li XF. Nontargeted Identification of an N-Heterocyclic Compound in Source Water and Wastewater as a Precursor of Multiple Nitrosamines. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:385-392. [PMID: 33284617 DOI: 10.1021/acs.est.0c06109] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
N-Nitrosamine disinfection byproducts (DBPs) are a health concern because they are probable human carcinogens. Complex organic nitrogenous compounds, nitrosamine precursors, are largely unidentified in source water. Using stable isotopic labeling-enhanced nontargeted analysis, we identified a natural product N-heterocyclic amine 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCCA) in source water. Interestingly, we discovered that chloramination of MTCCA-containing water could produce four nitrosamines: methylethylnitrosamine, N-nitrosopyrrolidine, N-nitrosoanatabine, and N-nitrosoanabasine. Computational modeling and experimental results helped explain potential pathways of nitrosamines generated from chloramination of MTCCA. Further investigations confirmed widespread occurrence of MTCCA in source water and wastewater. Its concentration ranged from high in upstream creeks (23.2-332.2 ng L-1) to low in the river (5.7-37.6 ng L-1) during the 2020 spring runoffs, indicating that sources of MTCCA came from creeks around farms. Analysis of wastewater before and after ultraviolet, as well as microfiltration with subsequent ozonation treatments, showed increased MTCCA after treatments, demonstrating a difficulty to degrade and remove MTCCA in water. This study discovered the extensive presence of MTCCA in source water and wastewater, suggesting that natural N-heterocyclic compounds may serve as a new source of nitrosamine precursors.
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Affiliation(s)
- Junlang Qiu
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Yi Zhang
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2G3, Canada
- School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Caley Craven
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2G3, Canada
- Department of Chemistry, Faculty of Science, University of Alberta, Edmonton, AB T6G 2G3, Canada
| | - Zhongshan Liu
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2G3, Canada
- School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
| | - Yanpeng Gao
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2G3, Canada
- School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Xing-Fang Li
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2G3, Canada
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Determination of N-Nitrosamines by Gas Chromatography Coupled to Quadrupole–Time-of-Flight Mass Spectrometry in Water Samples. SEPARATIONS 2020. [DOI: 10.3390/separations7010003] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
An analytical method based on high-resolution quadrupole–time-of-flight (QToF) mass spectrometry has been developed as an alternative to the classical method, using a low-resolution ion trap (IT) analyzer to reduce interferences in N-nitrosamines determination. Extraction of the targeted compounds was performed by solid-phase extraction (SPE) following the United States Environmental Protection Agency (USEPA) -521 method. First, both electron impact (EI) and positive chemical ionization (PCI) using methane as ionization gas were compared, along with IT and QToF detection. Then, parameters such as limits of detection (LOD) and quantification (LOQ), linearity, and repeatability were assessed. The results showed that the QToF mass analyzer combined with PCI was the best system for the determination of the N-nitrosamines, with instrumental LOD and LOQ in the ranges of 0.2–4 and 0.6–11 ng mL−1, respectively, which translated into method LOD and LOQ in the ranges of 0.2–1.3 and 0.6–3.9 ng L−1, respectively. The analysis of real samples showed the presence of 6 of the N-nitrosamines in influent, effluent, and tap water. N-nitrosodimethylamine (NDMA) was quantified in all the analyzed samples at concentrations between 1 and 27 ng L−1. Moreover, four additional nitrosamines were found in tap and wastewater samples.
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Ma G, Yu H, Xu T, Wei X, Chen J, Lin H, Schüürmann G. Computational Insight into the Activation Mechanism of Carcinogenic N'-Nitrosonornicotine (NNN) Catalyzed by Cytochrome P450. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11838-11847. [PMID: 30209943 DOI: 10.1021/acs.est.8b02795] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Tobacco-specific N'-nitrosonornicotine (NNN), a genotoxic nitrosamine classified as Group 1 carcinogen, is also present in atmospheric particulate matter and has even been detected as a new disinfection byproduct in wastewaters. NNN generally requires metabolic activation by cytochrome P450 enzymes to exert its genotoxicity, but the respective biotransformation pathways have not been described in detail. In this work, we performed density functional theory (DFT) calculations to unravel possible NNN activation pathways including α-hydroxylation, β-hydroxylation, pyridine N-oxidation, and norcotinine formation. The results reveal an initial rate-determining Hα-atom abstraction step for α-hydroxylation, followed by an unexpected kinetic competition between denitrosation and OH rebound, leading to ( iso-)myosmine as a detoxified product and α-hydroxyNNNs as the precursor of carcinogenic diazohydroxides, respectively. Further detoxification routes are given by β-hydroxylation with relative high reaction barrier and N-oxidation with comparable barrier to the toxifying α-hydroxylation. Moreover, we show for the first time how norcotinine can be generated as a minor NNN metabolite that is formed from iso-myosmine through a unique porphyrin-assisted H atom 1,2-transfer mechanism. These results demonstrate that the carcinogenic potential of NNN is subject to a kinetic competition between activating and deactivating metabolic routes, and identify respective biomarkers to inform about the individual risk associated with NNN exposure.
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Affiliation(s)
- Guangcai Ma
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Haiying Yu
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Ting Xu
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Xiaoxuan Wei
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Jianrong Chen
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Hongjun Lin
- College of Geography and Environmental Sciences , Zhejiang Normal University , Yingbin Avenue 688 , 321004 , Jinhua , China
| | - Gerrit Schüürmann
- UFZ Department of Ecological Chemistry , Helmholtz Centre for Environmental Research , Permoserstrasse 15 , 04318 , Leipzig , Germany
- Institute of Organic Chemistry , Technical University Bergakademie Freiberg , Leipzig Strasse 29 , 09596 Freiberg , Germany
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Richardson SD, Postigo C. Liquid Chromatography–Mass Spectrometry of Emerging Disinfection By-products. ADVANCES IN THE USE OF LIQUID CHROMATOGRAPHY MASS SPECTROMETRY (LC-MS) - INSTRUMENTATION DEVELOPMENTS AND APPLICATIONS 2018. [DOI: 10.1016/bs.coac.2017.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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9
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Cai B, Ji H, Fannin FF, Bush LP. Contribution of Nicotine and Nornicotine toward the Production of N'-Nitrosonornicotine in Air-Cured Tobacco (Nicotiana tabacum). JOURNAL OF NATURAL PRODUCTS 2016; 79:754-9. [PMID: 26959866 DOI: 10.1021/acs.jnatprod.5b00678] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
N'-Nitrosonornicotine (6) is a potent and organ-specific carcinogen found in tobacco and tobacco smoke in substantial amounts. Nicotine (1) and nornicotine (2) are proposed to be the precursors of 6 in tobacco. Since 1 can be rapidly demethylated to 2 in tobacco, to distinguish between the direct formation of 6 from these potential precursors is difficult. A gas chromatography/thermal energy analyzer method using two columns in series was developed to separate the enantiomers of 6, N'-nitrosoanabasine (7), and N'-nitrosoanatabine (8). Tobacco lines with different combinations of three nicotine demethylases inhibited were grown in the field. Air-cured leaves were analyzed for the enantiomeric composition of four main alkaloids and their corresponding tobacco-specific nitrosamines. The percentage of (R)-6 of total 6 varied from 7% to 69% in mutant lines. The measured 6 had the same enantiomeric composition as 2, rather than 1, even when the level of 2 was reduced to 0.6% of 1 in a triple mutant line. The pattern of the enantiomeric composition of 1, 2, and 6 demonstrated that the direct formation of 6 from 1, if it occurs, is negligible in air-cured tobacco. Since (S)-6 is more highly carcinogenic than its R form, the reduction of (S)-2 should be a priority for the reduction of 6.
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Affiliation(s)
- Bin Cai
- Guizhou Academy of Tobacco Science , Guiyang, Guizhou 550081, People's Republic of China
- Department of Plant and Soil Sciences, University of Kentucky , Lexington, Kentucky 40546-0312, United States
| | - Huihua Ji
- Department of Plant and Soil Sciences, University of Kentucky , Lexington, Kentucky 40546-0312, United States
| | - Franklin F Fannin
- Department of Plant and Soil Sciences, University of Kentucky , Lexington, Kentucky 40546-0312, United States
| | - Lowell P Bush
- Department of Plant and Soil Sciences, University of Kentucky , Lexington, Kentucky 40546-0312, United States
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Affiliation(s)
- Susan D. Richardson
- Department of Chemistry and
Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
| | - Susana Y. Kimura
- Department of Chemistry and
Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
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