Journal of Environmental Sciences
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2016
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IF 2.208
Xianze Wang,Zhongmou Liu,Chi Wang,Zhian Ying,Wei Fan,Wu Yang
The presence of mutagenic and carcinogenic nitrosamines in water is of great concern. In this study, seven nitrosamines including N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPyr), N-nitrosopiperidine (NPip), N-nitrosodi-n-propylamine (NDPA), and N-nitrosodi-n-butyl-amine (NDBA) were investigated in river water and ground water samples collected from 5 representative cities (Jilin, Songyuan, Harbin, Jiamusi and Tongjiang) along the Songhua River. The total concentrations of nitrosamines in ground water were n.d. (not detected) to 60.8 ng/L, NDMA was the most frequently detected nitrosamines in ground water, followed by NDEA and NPip. Relatively high detected frequency and concentrations of NDMA were also observed in river water samples, and the total nitrosamines' concentration at midstream is always higher than that at upstream and downstream. After 24 hr chlorination, concentration of NDMA, NDBA was obviously increased but NDEA was reduced. Furthermore, UV 254 showed a better relationship with NDMA-FP rather than dissolved organic carbon (DOC), NH 4 -N, and TDN.
研究领域:
环境科学
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公共卫生
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DOI
PubMed
高影响因子
Oncotarget
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2017
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IF 5.168
Jie Gao,Gao-Ju Wang,Zhao Wang,Na Gao,Jing Li,Yun-Fei Zhang,Jun Zhou,Hong-Xin Zhang,Qiang Wen,Han Jin,Hai-Ling Qiao
Hepatofibrosis, which leads to cirrhosis and eventual hepatocellular carcinoma, is a common response to chronic toxin-mediated liver injury. Nitrosamines are potent hepatotoxic agents that cause necrosis and subsequent fibrosis in the liver as a result of cytochrome P450 2E1 (CYP2E1)-dependent metabolism, which generates toxic metabolites that form adducts with nucleic acids, leading to hepatotoxicity and mutagenesis. Herein, CYP2E1 activity and content were determined in fibrotic liver tissue from patients with hepatocellular carcinoma. The relationship between CYP2E1 innate activity and hepatofibrogenesis was evaluated, the effect of inhibition of CYP2E1 activity on hepatofibrosis was determined in a Sprague-Dawley rat model of diethylnitrosamine-induced hepatofibrosis. The results demonstrated that the CYP2E1 activities in human fibrotic tissues are significantly higher than that in normal liver tissues. In rats treated with diethylnitrosamine, the livers demonstrated various degree of fibrotic changes and collagen deposition in individual rats. The Ishak score, which determines the stage of fibrosis, correlated with CYP2E1 innate activity, with greater fibrosis in rat livers with higher CYP2E1 innate activity. Inhibition of CYP2E1 during diethylnitrosamine treatment decreased hepatofibrosis and there was an inverse correlation between the degree of inhibition and the extent of hepatofibrosis. Therefore, high CYP2E1 activity is a risk factor for hepatofibrogenesis induced by nitrosamines.
研究领域:
医学
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毒理学
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肝脏研究
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PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL ENGINEERING
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2021
·Vol. 147
·期 10
·04021038
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IF 1.86
Yanling Guo,Yanan Cheng,Bingli Wang,Xueke Li,Wanfeng Wang
Nitrosamines have become a focus of considerable research because of their carcinogenicity and environmental universality. In this study, to effectively remove nitrosamines, biological activated carbon (BAC) was acclimatized by a nitrosamine-reducing bacterial strain, and zero-valent iron (Fe0)-assisted BAC was used to degrade nitrosamines from aqueous solution. The influencing factors and degradation mechanism were investigated. Compared with activated carbon (AC), the removal efficiency of more strongly polar nitrosamines by BAC and BAC_Fe0 increased prominently (21.0%–32.3%), yet there was no change between BAC and BAC_Fe0. The highest ratios of nitrosamine degradation by BAC_Fe0 were 49.8%–99.0%, and degradation reaction kinetics conformed best to a pseudo-second-order model (?2>0.9269). The rate constants ?obs for six nitrosamines ranged from 3.4×103 to 6.9 × 105 (M · s)−1. Additionally, the removal ratios and ?2 of the linear nitrosamines partially scaled with their molecular weight, Log??, and Log??? (?2=0.5661−0.952). All nitrosamines were degraded within 30 min under strong acidic conditions; the removal ratios increased by 11.2%−23.1% under anaerobic conditions, but were decreased by ∼10% in the presence of humic acid. The primary degradation products were secondary amines, methylamine, formic acid, nitrate, and nitrite resulting from the reduction of Fe0 and biodegradation by the nitrosamine-reducing bacteria.
研究领域:
环境科学
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微生物学
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材料科学
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DOI
高影响因子
WATER RESEARCH
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2024
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IF 11.4
Peizeng Yang,Hailing Chu,Jiating Liu,Teng Zhang,Junhe Lu
Sulfate radical (SO 4 •− ) advanced oxidation processes (SR-AOPs) are efficient for degrading a broad spectrum of contaminants. This study demonstrates that the existence of environmentally relevant concentrations of nitrite (NO 2 − ) can lead to the formation of N -nitrosodimethylamine (NDMA), a probable human carcinogen, when heat activated peroxydisulfate (heat/PDS) is applied to address contaminants with dimethylamine moieties, such as tetracyclines. NO 2 − effectively competes with tetracyclines for SO 4 •− at a high second-order reaction rate constant of 8.8 × 10 8 M −1 s −1 , thus suppressing the degradation. Simultaneously, SO 4 •− reacts with NO 2 − to form the nitrogen dioxide radical (NO 2 • ) which rapidly dimerizes to a potent nitrosating agent named dinitrogen tetroxide (N 2 O 4 ). N 2 O 4 , in turn, attacks the dimethylamine moiety in tetracyclines via nucleophilic substitution, contributing to the degradation of parent compounds and generating an active intermediate that quickly decomposes to NDMA, along with the release of R + and NO 3 − . The released R + can be further oxidized by SO 4 •− to form phenolic intermediates which combine with NO 2 • to generate nitrated products. When 5 μM oxytetracycline (OTC) was treated with 0.5 mM PDS in the presence of 20 μM NO 2 − at 60 °C, the highest formation of NDMA was 0.045 μM in 1 h. NDMA formation was also observed for other compounds with dimethylamine moieties, such as methylene blue, phenylurea herbicides, etc., with the molar yield ranging from 0.07 to 3.53 %, negatively related to the R-N bond dissociation energy of the precursors. These findings suggest that NDMA can be commonly generated when SO 4 •− is applied to the degradation of dimethylamine pollutants in wastewater treatment or groundwater remediation where NO 2 − ubiquitously exists, which may pose a serious threat to the aquatic environment.
研究领域:
环境科学
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毒理学
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PubMed
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2024
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IF 10.8
Yi-Hsueh Chuang,Chia-Shun Chou,Yi-Lin Chu
Chlorination of ammonia or chloramine-containing waters induces breakpoint chlorination reactions, producing a hydroxyl radical (•OH), but enhances the formation of undesirable N-nitrosamines. The prevailing view attributes •OH formation to a nitrosyl intermediate derived from the hydrolysis of dichloramine, but this pathway is unlikely at neutral or acidic pH. This study reveals a novel mechanism where •OH is generated via interactions between trichloramine (NCl3) and dichloramine (NHCl2), which also form nitrosation agents. Our experiments demonstrated that the NCl3–NHCl2 interaction degrades micropollutants with kinetics 2–3 times faster than breakpoint chlorination. Using electron paramagnetic resonance, we detected •OH in the NCl3–NHCl2 reaction. Micropollutant removal was unimpaired under low dissolved oxygen (O2(aq)) conditions, aligning with negligible O2(aq) changes during the NCl3–NHCl2 reaction and suggesting O2(aq) does not participate in •OH formation. Using benzene as a probe in 18O-labeled H2O, we confirmed water contributes to the oxygen source of •OH in NCl3–NHCl2 interactions, through which parallel reactions occur, leading to the formation of one mole of •OH alongside 1.92 mol of N2. A kinetic model developed in this study accurately predicted •OH and N2 and demonstrated the NCl3–NHCl2 interaction as the primary pathway for •OH formation in breakpoint chlorination, providing new insights into breakpoint chemistry.
研究领域:
环境科学
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化学工程
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PubMed
高影响因子
Natural Product Communications
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2020
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IF 0.468
YanHua Tian,HuiZhi Du,Li Wang,ShiFei Li,Lu Zhang,LiWei Zhang
Diospyros lotus L. leaves are used as a functional tea and folk medicine in several Asian countries. This study aimed to evaluate the effects of phenolic extracts of the leaves on scavenging nitrite and inhibiting N-nitrosamines (NAs) formation and to determine the active ingredients responsible for these effects. Of the 7 fractions (Fr1-Fr7) prepared from the extract of D. lotus leaves, Fr5 contained the highest phenolic content and exhibited the strongest activity. Five active ingredients of Fr5 were discovered, and 4 of them were identified as myricitrin (Mytr), myricetin (Myt), myricetin-3-O-β-d-glucoside (Myt-Glc), and myricetin-3-O-β-d-galactoside (Myt-Gal). The content of Mytr was much higher than those of the other 3 ingredients, both in Fr5 and extracts of D. lotus leaves. Finally, Mytr and Myt were proved to have stronger activities by the 1,1-diphenyl-2-trinitrophenyl hydrazine scavenging, nitrite scavenging, and inhibition of NAs formation assays. These results indicated that Mytr was the main active ingredient of D. lotus leaves. Myt, Mytr, and Fr5 from the leaves could be used as natural agents for antioxidant, nitrite scavenging, and inhibition of NAs formation in food and the human body.
研究领域:
食品科学
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植物化学
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药理学
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高影响因子
Food & Function
·
2019
·Vol. 10
·期 2
·625-634
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IF 3.241
Jieyu Wu,Rongfa Guan,Haizhi Huang,Zhenfeng Liu,Haitao Shen,Qile Xia
The instability of catechins (CT) is currently a challenge for their application in the food industry. This study explored whether or not the protective effects of liposome encapsulation on CT could enhance the role of CT as antioxidants in reducing nitrosamines (NAs) in traditional Chinese bacon (TCB). The samples were further characterized by the analysis of volatile compounds, color parameters, and texture profile during storage to assess the effects of catechin liposomes (CTL) on TCB. Results showed that the increase in NAs in fried TCB was strongly dependent on the storage time. CTL could reduce the production of NAs in fried TCB (40.45%) more strongly than CT (15.13%) after 49 days of storage. Higher phenol contents were found in CTL (1515.25 × 106 area unit (AU)) than those in control (1451.73 × 106 AU) and CT (1391.10 × 106 AU) TCB at the end of storage. The addition of antioxidants increased (p < 0.05) a* values in the following order: CTL > CT > control with mean values of 6.54, 5.09, and 3.92, respectively, after 49-day storage. Conversely, the addition of CTL decreased (p < 0.05) the hardness of TCB. Encapsulating CT in the liposomes can effectively reduce the NAs in TCB and positively affect its quality. This technique may guide the potential application of liposomes in the meat industry.
研究领域:
食品科学
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生物学
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营养学
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PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2020
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IF 6.551
Xiaochao Duan,Xiaobin Liao,Jianfei Chen,Shuguang Xie,Huan Qi,Fei Li,Baoling Yuan
Disinfection is an indispensable process to inactivate pathogens , while unexpected disinfection by-products (DBPs) would also be formed between the reaction of residual disinfectants and microorganisms in the water distribution system (WDS). However, there are few studies referring to the formation of DBPs and DBPs-associated toxicity under various disinfection methods based on microorganisms in the real WDS. In addition, the main contributors of bacterial communities or components that generate DBPs are unclear. In this study, the formation of trihalomethanes (THMs), halo-acetic acids (HAAs), nitrosamines (NAs) from culturable microorganisms in pipeline network by ozonation(O 3 ), chlorination (Cl 2 ), chloramination (NH 2 Cl) and joint disinfection methods were compared, meanwhile, their calculated toxicities under different oxidation scenarios were also discussed. Moreover, 16S ribosomal ribonucleic acid (rRNA) gene sequencing was used to identify the main microbial communities . The results demonstrated that THMs and HAAs increased with increasing disinfectant dosages, while the quantity of NAs (mainly nitroso dimethylamine (NDMA)) was not significantly related to disinfectant dosages for each disinfection strategy. Chloroform (TCM) and dichloroacetic acid (DCAA) were the dominant THMs and HAAs species, respectively. NDMA existed in the samples before disinfections, which may due to the metabolic activity of microorganisms. Pre-O 3 increased THMs formation during subsequent Cl 2 and NH 2 Cl treatment. However, pre-O 3 effectively reduced HAAs produced by subsequent chlorination. O 3 /Cl 2 disinfection had the highest DBPs formation potential (DBPFP) (883.6 nM), while its calculated toxicity was similar to that in Cl 2 disinfection treatment. Pseudomonas was the most abundant bacterial genus in biofilm of WDS pipeline. This study can aid in an optimal disinfection strategy for water treatment plants to reduce the toxicity of DBPs caused by biomass in pipelines and ensure water quality safety.
研究领域:
环境科学
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微生物学
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DOI
PubMed
高影响因子
Foods
·
2023
·Vol. 12
·期 2
·394
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IF 5.2
Jingnan Lu,Mingyu Li,Mingyue Shen,Jianhua Xie,Mingyong Xie
Advanced glycation end products (AGEs) and nitrosamines (NAs) in sausage are associated with pathogenic and carcinogenic risks. However, the multiple reaction parameters affecting the production of AGEs and NAs during sausage processing remain unclear. This experiment evaluated the effects of processing parameters, food additives and fat ratios on the formation of AGEs and NAs in sausages. The results showed a 2–3-fold increase in Nε-(carboxymethyl)lysine (CML) and Nε-(carboxyethyl)lysine (CEL) when the sausage processing temperature was increased from 90 °C to 130 °C, and N-nitrosodimethylamine (NDEA) increased from 3.68 ng/g to 6.41 ng/g. The addition of salt inhibited the formation of AGEs and NAs, and the inhibitory ability of 2 g/100 g of salt was 63.6% for CML and 36.5% for N-nitrosodimethylamine (NDMA). The addition of 10 mg/kg nitrite to sausages reduced CML formation by 43.9%, however, nitrite had a significant contribution to the formation of NAs. The addition of fat only slightly contributed to the production of CML. In addition, the relationship between α-dicarbonyl compounds and the formation of AGEs was investigated by measuring the changes in α-dicarbonyl compounds in sausages. The results showed two trends of AGEs and α-dicarbonyl compounds: AGEs increased with the increase in α-dicarbonyl compounds and AGE level increased but α-dicarbonyl compound level decreased.Keywords:advanced glycation end products;nitrosamines;α-dicarbonyl compounds;sausages
研究领域:
食品科学
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医学
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营养学
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF FOOD PROPERTIES
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2019
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IF 1.398
Ling Li,Hui Ji
The present study investigated the protective effects of the polyphenol epicatechin on the protein structural changes, gel properties and N-nitrosodiethylamine (NDEA) formation of oxidatively stressed myofibrillar protein (MP). Results showed that oxidation treatments to MP significantly increased their carbonyl content and surface hydrophobicity as compared to the control groups (p < 0.05). Epicatechin inhibited protein carbonyl content and surface hydrophobicity, especially treated with 2 mM epicatechin. Under oxidative conditions, the fluorescence intensity of tryptophan gradually decreased with the increase of epicatechin concentrations from 0 to 2 mM. The storage modulus (G’) was increased gradually after oxidation and epicatechin treatment. Epicatechin reduced the loss of P22 and water holding capacity (WHC), promoted the hydration of the proteins. Under oxidative conditions, epicatechin had a concentration dependent effect on the formation of NDEA; low concentrations of epicatechin promoted NDEA formation, while high concentrations inhibited NDEA production. In conclusion, an appropriate quantity of polyphenols can inhibit the oxidation of MP and formation of N-nitrosamines.
研究领域:
食品科学
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生物化学
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DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2018
·Vol. 229
·期 3
·1-11
·
IF 1.769
Huang Danping,Li Hanmin,He Qidi,Yuan Weiqu,Chen Zuanguang,Yang Hongzhi
Diethylnitrosamine (DEN) is present in food, water, and daily supplies and is regarded as a toxicant of carcinogenicity. The developmental toxicity of DEN has been rarely reported as yet. In this study, zebrafish were exposed to different concentrations of DEN at 6 h post-fertilization (hpf) to access embryonic toxicity of the compound. The results show that DEN resulted in negative effects of hatching rate, heartbeat, body length, and spontaneous movement. Deformities, including notochord malformation, pericardium edema, embryonic membrane turbidity, tail hypoplasia, yolk sac deformity, and growth retardation, happened during exposure period. Moreover, production of reactive oxygen species (ROS) significantly increased after DEN treatment. Then, alterations of the expression level of oxidative stress-related genes were observed in our results. To our knowledge, this is the first study concerning the effect of DEN on zebrafish. And from the information of our research, we speculated that development toxicity of DEN should be related to the excessive oxidative stress.
研究领域:
毒理学
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发育生物学
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环境科学
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PubMed
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
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2021
·Vol. 105
·期 13
·5607-5616
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IF 4.813
He Ying,Ding Haotian,Xia Xingya,Qi Wenyi,Wang Huaisong,Liu Wenyuan,Zheng Feng
Abstract Nitrosamine compounds, represented by N -nitrosodimethylamine, are regarded as potentially genotoxic impurities (PGIs) due to their hazard warning structure, which has attracted great attention of pharmaceutical companies and regulatory authorities. At present, great research gaps exist in genotoxicity assessment and carcinogenicity comparison of nitrosamine compounds. In this work, a collection of GFP-fused yeast cells representing DNA damage repair pathways were used to evaluate the genotoxicity of eight nitrosamine compounds (10 −6 –10 5 μg/mL). The high-resolution expression profiles of GFP-fused protein revealed the details of the DNA damage repair of nitrosamines. Studies have shown that nitrosamine compounds can cause extensive DNA damage and activate multiple repair pathways. The evaluation criteria based on the total expression level of protein show a good correlation with the mammalian carcinogenicity data TD 50 , and the yeast cell collection can be used as a potential reliable criterion for evaluating the carcinogenicity of compounds. The assay based on DNA damage pathway integration has high sensitivity and can be used as a supplementary method for the evaluation of trace PGIs in actual production. Key points • The genotoxicity mechanism of nitrosamines was systematically studied . • The influence of compound structure on the efficacy of genotoxicity was explored . • GFP-fused yeast cells have the potential to evaluate impurities in production . Graphical abstract
研究领域:
毒理学
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分子生物学
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药学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）