Speckled trout, Salvelinus fontinalis, were orally exposed to individual polycyclic aromatic compounds (PACs) represented by benzo[a]pyrene, carbazole, chrysene, dibenzofuran, dibenzothiophene, fluorene, phenanthrene, and pyrene. Fish were sacrificed 7 days after exposure and the gall bladder removed for bile analysis. High pressure liquid chromatography (HPLC) with fluorescence (F) and ultraviolet (UV) detection was used to determine the presence of PAC derivatives in the bile without pretreatment. Glucuronide conjugates were predominant in all exposures with variable amounts (0-53%) of phenols and starting material. Identification of compounds was confirmed by selective extraction of less polar nonconjugated PACs and enzymatic hydrolysis of water-soluble material. This was followed by HPLC and/or gas chromatography-mass spectrometry (GCMS) characterization of the produced phenols. Total metabolite levels varied widely among compounds.
Yields trans-4,5-dihydro-4,5-dihydroxypyrene, s-(4,5-dihydro-4-hydroxypyren-5-yl)glutathione, 1,6-dihydroxypyrene, 1,8-dihydroxypyrene, and 1-hydroxypyrene in rats and rabbits.
For K-region of pyrene (4,5 bond), no evidence of phenol formation is found, 4,5-dihydrodiol is detected in relatively small amt, and no 4,5-dihydroxypyrene derivatives are found. Major metabolite appears to be mercapturic acid, n-acetyl-s-(4,5-dihydro-4-hydroxy-5-pyrenyl)l-cysteine.
PAH metabolism occurs in all tissues, usually by cytochrome P-450 and its associated enzymes. PAHs are metabolized into reactive intermediates, which include epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations. The phenols, quinones, and dihydrodiols can all be conjugated to glucuronides and sulfate esters; the quinones also form glutathione conjugates. (L10)
IDENTIFICATION AND USE: Pyrene is a solid. It can be used as an additive in electro-insulating oils as well as in epoxy resins for electrical insulation. Optical brighteners can be synthesized by reaction of pyrene with a complex of cyanuric chloride and aluminum chloride. Pyrene itself can serve as an electron donor to enhance the blackness in pencil leads. It is also used in biochemical research. HUMAN EXPOSURE AND TOXICITY: Exposure to the sun may provoke an irritating effect of pyrene on skin and lead to chronic skin discoloration. Pyrene, but not related polyaromatic hydrocarbons, enhanced basal transcription of the human and mouse IL-4 promoter. ANIMAL STUDIES: Dermal exposure to 10 g/kg was not lethal in mice. Inhalation caused pathological changes in hepatic, pulmonary, and intragastric tissue and a decrease in the number of neutrophils, leukocytes, and erythrocytes. No blastomogenic or carcinogenic effects were noted, except for an occasional papilloma. Some teratogenic effects were noted. Pyrene induced mutations and unscheduled DNA synthesis in some in vitro assays in mammalian cells. There is limited evidence that pyrene is active in short-term assays. ECOTOXICITY STUDIES: There was an interaction between pyrene and the thyroid system in fish. In rockfish, pyrene exposure impaired skeleton development via disrupting the proliferation of the chondrocytes. Embryonic exposure of zebrafish to low-level environmental pyrene disrupted normal cardiac development and altered expression of defective cardiac differentiation related genes. Pyrene might be a contributor to the behavioral and neuro-developmental toxicity in pufferfish. in the earthworm Lumbricus rubellus pyrene was found to cause a dose dependant decrease in lactate and the concentrations of the saturated fatty acids tetradecanoic, hexadecanoic and octadecanoic acid and an increase in production of the amino acids alanine, leucine, valine, isoleucine, lysine, tyrosine and methionine. It is proposed that this indicates impaired glucose metabolism, with an associated increase in fatty acid metabolism and changes in TCA cycle intermediates.
The ability of PAH's to bind to blood proteins such as albumin allows them to be transported throughout the body. Many PAH's induce the expression of cytochrome P450 enzymes, especially CYP1A1, CYP1A2, and CYP1B1, by binding to the aryl hydrocarbon receptor or glycine N-methyltransferase protein. These enzymes metabolize PAH's into their toxic intermediates. The reactive metabolites of PAHs (epoxide intermediates, dihydrodiols, phenols, quinones, and their various combinations) covalently bind to DNA and other cellular macromolecules, initiating mutagenesis and carcinogenesis. (L10, L23, A27, A32)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌性证据
总评:第3组:该物质对人类致癌性无法分类。
OVERALL EVALUATION: Group 3: The agent is not classifiable as to its carcinogenicity to humans.
... Rats were treated with Benzo(a)pyrene (BaP) (150 ug/kg) alone or with phenanthrene (PH) (4,300 ug/kg) and pyrene (PY) (2,700 ug/kg) (BPP group) by oral gavage once per day for 30 days. 7-ethoxyresorufin-O-deethylase activity in liver microsomal fraction was increased in only BaP groups. The highest concentration (34.5 ng/g) of BaP, was found in muscle of rats treated with BaP alone at 20 days of treatment; it was 23.6 ng/g in BPP treated rats at 30 days of treatment. The highest PH concentration was 47.1 ng/g in muscle and 118.8 ng/g in fat, and for PY it was 29.7 ng/g in muscle and 219.9 ng/g in fat, in BPP groups. In urine, 114-161 ng/mL 3-OH-PH was found, while PH was 41-69 ng/mL during treatment. 201-263 ng/mL 1-OH-PY was found, while PH was 9-17 ng/mL in urine. The level of PY, PH and their metabolites in urine was rapidly decreased after withdrawal of treatment ...
... This human control study examined the excretion kinetics of urinary 1-hydroxypyrene (1-OHP) after consuming barbecued meat. Two feeding experiments were conducted, with doses of 15 and 30 g of barbecued meat per kg of body weight for experiments 1 and 2, respectively. All voided urine was collected for 7 days and analyzed for 1-OHP. In both experiments, the amounts of urinary 1-OHP excreted was significantly increased (P < 0.05) at 12 hr post exposure but not at 12-24 hr post exposure. Mean percentages of administered pyrene doses excreted as urinary 1-OHP at 0-12 hr and 12-24 hr post exposure were 3.80 and 0.61% in experiment 1 and 1.66 and 0.38% in experiment 2. Excretion ratio was inversely related to dose. A pattern of diurnal fluctuation (P < 0.05) in 1-OHP excretions was also identified. That is, 1-OHP excretions were smaller in the first half of the day (~0:00-12:00) than in the last half of the day (~12:00-24:00). This study demonstrated that, even at large dietary doses, most of the total urinary excretion of 1-OHP occurs within 12 hr. Thus, subjects of occupational or environmental studies need only recall their diets for the current or previous day to diminish the influence from dietary pyrene.
... Two groups of Buccinum undatum were exposed to equimolar amounts of pyrene and 1-hydroxypyrene over 15 d through their diets. Tissue extracts from the muscle and visceral mass were analyzed by liquid chromatography with fluorescence and mass spectrometry detection. Nine biotransformation products were detected in animals from both exposures. These included 1-hydroxypyrene, pyrene-1-sulfate, pyrene-1-glucuronide, pyrene glucose sulfate, two isomers each of pyrenediol sulfate and pyrenediol disulfate, and one isomer of pyrenediol glucuronide sulfate. These compounds represent a more complex metabolic pathway for pyrene than is typically reported. Diconjugated metabolites were as important in animals exposed to pyrene as in those exposed to 1-hydroxypyrene. Biotransformation products represented >90% of the material detected in the animals and highlight the importance of analyzing metabolites when assessing exposure. A mean of only 2 to 3% of the body burden was present in muscle compared with the visceral mass of both groups. The analytical methods were sufficiently sensitive to detect biotransformation products both in laboratory control whelks and in those sampled offshore. The tissue distribution of [(14)C]pyrene was also studied by autoradiography. Radioactivity was present primarily in the digestive and excretory system of the whelks and not in the gonads or muscle tissue.
... Transfer of 10 polynuclear aromatic hydrocarbons (PAHs) (pyrene, 3,4-benzophenanthrene, triphenylene, chrysene, 1,2-benzanthracene, 1,1'-binaphthyl, 9-phenylanthracene, 2,2'-binaphthyl, m-tetraphenyl and 1,3,5-triphenylbenzene) out of phosphatidylcholine vesicles has been examined. Our results show that the molecular volume of the PAH is a rate-determining factor. Moreover, high performance liquid chromatography (HPLC) data confirms the hypothesis that the rate of transfer is correlated with the size of the molecule and with the partitioning of the molecule between a polar and hydrocarbon phase. The kinetics and characteristics of the spontaneous transfer of carcinogens are likely to have a major impact on the competitive processes of PAH metabolism within cells.
1.周国泰,化学危险品安全技术全书,化学工业出版社,1997 2.国家环保局有毒化学品管理办公室、北京化工研究院合编,化学品毒性法规环境数据手册,中国环境科学出版社.1992 3.Canadian Centre for Occupational Health and Safety,CHEMINFO Database.1998 4.Canadian Centre for Occupational Health and Safety, RTECS Database, 1989
White‐Fluorescent Dual‐Emission Mechanosensitive Membrane Probes that Function by Bending Rather than Twisting
作者:Heorhii V. Humeniuk、Arnulf Rosspeintner、Giuseppe Licari、Vasyl Kilin、Luigi Bonacina、Eric Vauthey、Naomi Sakai、Stefan Matile
DOI:10.1002/anie.201804662
日期:2018.8.13
Bent N,N′‐diphenyl‐dihydrodibenzo[a,c]phenazine amphiphiles are introduced as mechanosensitivemembraneprobes that operate by an unprecedented mechanism, namely, unbending in the excited state as opposed to the previously reported untwisting in the ground and twisting in the excited state. Their dualemission from bent or “closed” and planarized or “open” excited states is shown to discriminate between
弯曲的N,N'-二苯基-二氢二苯并[a,c]吩嗪两亲物被引入作为机械敏感膜探针,其通过前所未有的机制工作,即在激发态下不弯曲,而不是之前报道的在地面中不扭曲和在室温下扭曲。兴奋状态。它们从弯曲或“闭合”和平面化或“开放”激发态的双重发射被证明可以区分水中的胶束和固序(S o )、液体无序(L d )和本体膜中的单体。双发射光谱覆盖了足够的可见光范围,以产生发出带有比例编码信息的白光的囊泡。报告了通过扩展 π 系统和助色团来改善弯曲机械载体的策略,并证明了与双光子激发荧光 (TPEF) 显微镜对巨型单层囊泡中膜域成像的兼容性。
The invention relates to a method for producing peptoidic, peptidic and chimeric peptidic-peptoidic dendrimers by multiple iterative multi-component reactions (MCR), in particular Ugi or Passerini multi-component reactions, to compounds produced in this way and to the use thereof.
Indolizine–Squaraines: NIR Fluorescent Materials with Molecularly Engineered Stokes Shifts
作者:Louis E. McNamara、Tana A. Rill、Aron J. Huckaba、Vigneshraja Ganeshraj、Jacqueline Gayton、Rachael A. Nelson、Emily Anne Sharpe、Amala Dass、Nathan I. Hammer、Jared H. Delcamp
DOI:10.1002/chem.201702209
日期:2017.9.12
near infrared emissive materials with highquantumyields is an important challenge. Several classes of squaraine dyes have demonstrated highquantumyields, but require significantly red-shifted absorptions to access the NIR window. Additionally, squaraine dyes have typically shown narrow Stokes shifts, which limits their use in living biological imaging applications due to dye emission interference