Zebrafish embryo assays are increasingly used in the toxicological assessment of endocrine disruptors. Among other advantages, these models are 3R-compliant and are fit for screening purposes. Biotransformation processes are well-recognized as a critical factor influencing toxic response, but major gaps of knowledge exist regarding the characterization of functional metabolic capacities expressed in zebrafish. Comparative metabolic studies between embryos and adults are even scarcer. Using (3)H-labeled chemicals, we examined the fate of two estrogenic emerging contaminants, benzophenone-2 (BP2) and bisphenol S (BPS), in 4-day embryos and adult zebrafish. BPS and BP2 were exclusively metabolized through phase II pathways, with no major qualitative difference between larvae and adults except the occurrence of a BP2-di-glucuronide in adults. Quantitatively, the biotransformation of both molecules was more extensive in adults. For BPS, glucuronidation was the predominant pathway in adults and larvae. For BP2, glucuronidation was the major pathway in larvae, but sulfation predominated in adults, with ca. 40% conversion of parent BP2 and an extensive release of several conjugates into water. Further larvae/adults quantitative differences were demonstrated for both molecules, with higher residue concentrations measured in larvae. The study contributes novel data regarding the metabolism of BPS and BP2 in a fish model and shows that phase II conjugation pathways are already functional in 4 days post-fertilization old zebrafish. Comparative analysis of BP2 and BPS metabolic profiles in zebrafish larvae and adults further supports the use of zebrafish embryo as a relevant model in which toxicity and estrogenic activity can be assessed, while taking into account the absorption and fate of tested substances.
Twelve derivatives of benzophenone (BP1-BP12) are widely used as UV-screens to protect industrial products from light induced damage. There is growing public concern about industrially produced chemicals that might interfere with hormonal signaling pathways, thus having potential adverse effects on human health. The derivative 2,2',4,4'-tetrahydroxybenzophenone (BP2) which is used in cosmetic products and in packaging materials, was previously shown to be an estrogenic endocrine active chemical (EAC). While the metabolization of BP3 has been analyzed in vivo, according to our knowledge little is known about the pharmacokinetics of BP2. Therefore we performed a dose-response experiment with 5 dosages of BP2 /10, 33, 100, 333 or 1000 mg/kg body weight/ which was applied per gavage to adult ovariectomized (ovx) rats for 5 days. Serum samples were analyzed via HPLC. Metabolites were further identified by Helix pomatia glucuronidase treatment and subsequent ion-trap-mass spectrometry. Additionally we analyzed the time dependent metabolization and excretion of BP2 in a kinetic study. The parent compound BP2 is metabolized to glucuronide - and sulfate-conjugates. In the serum maximum levels of BP2, BP2-glucuronide and BP2-sulfate were observed already 30 min after BP2 application while highest concentrations of BP2 and its metabolites in urine were measured 120 min after treatment. It is suggested that this biotransformation occurs via a first-pass effect in the gut wall or the liver. Despite this rapid metabolization and excretion, the amount of unconjugated BP2 was sufficient to induce a dose dependent estrogenic effect in the uterotrophic assay.
Benzophenone-2 (BP2) is widely used as a UV screen in both industrial products and cosmetic formulations, where it is frequently found associated with fragrance compounds, such as isoeugenol and coumarin. BP2 is now recognized as an endocrine disruptor, but to date, no information has been reported on its fate in humans. The intrinsic clearance (Clint) and metabolic interactions of BP2 were explored using cryopreserved human hepatocytes in primary cultures. In vitro kinetic experiments were performed to estimate the Michaelis-Menten parameters. The substrate depletion method demonstrated that isoeugenol was cleared more rapidly than BP2 or coumarin (Clint = 259, 94.7 and 0.40 uL/min/10(6) cells respectively). This vitro model was also used to study the metabolic interactions between BP2 and isoeugenol and coumarin. Coumarin exerted no effects on either isoeugenol or BP2 metabolism, because of its independent metabolic pathway (CYP2A6). Isoeugenol appeared to be a potent competitive substrate inhibitor of BP2 metabolism, equivalent to the specific UGT1A1 substrate: estradiol. Despite the fact that inhibition of UGT by xenobiotics is not usually considered to be a major concern, the involvement of UGT1A1 in BP2 metabolism may have pharmacokinetic and pharmacological consequences, due to the its polymorphisms in humans and its pure estrogenic effect.
Several human and fish bioassays have been designed to characterize the toxicity and the estrogenic activity of chemicals. However, their biotransformation capability (bioactivation/detoxification processes) is rarely reported, although this can influence the estrogenic potency of test compounds. The fate of two estrogenic chemicals, the UV filter benzophenone-2 (BP2) and the bisphenol A substitute bisphenol S (BPS) was deciphered in eight human and zebrafish in vitro cell models, encompassing hepatic and mammary cellular contexts. BP2 and BPS were metabolized into a variety of gluco- and sulfo-conjugated metabolites. Similar patterns of BP2 and BPS biotransformation were observed among zebrafish models (primary hepatocytes, ZFL and ZELH-zfER cell lines). Interestingly, metabolic patterns in zebrafish models and in the human hepatic cell line HepaRG shared many similarities, while biotransformation rates in cell lines widely used for estrogenicity testing (MELN and T47D-KBLuc) were quantitatively low and qualitatively different. This study provides new data on the comparative metabolism of BP2 and BPS in human and fish cellular models that will help characterize their metabolic capabilities, and underlines the relevance of using in vitro zebrafish-based bioassays when screening for endocrine disrupting chemicals.
IDENTIFICATION AND USE: Benzophenone-2 (BP2) is used as UV filter in a personal care products. Benzophenone-2 is commonly used in cosmetic products and food container plastics to filter out ultraviolet light. HUMAN STUDIES: Sensitization against benzophenone-2 has been reported. BP2, may disturb thyroid hormone homeostasis by inhibiting or inactivating thyroid peroxidase, effects that are even more pronounced in the absence of iodide. ANIMAL STUDIES: Benzophenone-2 was estrogenic in vitro and in the rat uterotropic assay. BP2 was shown to bind to the estrogen receptors. Benzophenone-2 was reported to be positive for mutagenicity using Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 with metabolic activation. An in vitro cytogenic assay was used to evaluate the ability of Benzophenone-2 to induce sister chromatid exchange (SCE) and chromosome aberrations (CA) in L5178Y mouse lymphoma cells. Benzophenone-2 does not directly induce significant SCE or CA increases but does, under metabolic activation, induce these changes. Benzophenone-2 induced an increase in mutations at the TK locus in L5178Y mouse lymphoma cells only for highly toxic doses with or without metabolic activation. UV-screens at high doses also may possess immunomodulatory effects some of which resemble those of 17beta-estradiol. ECOTOXICITY STUDIES: BP2 is estrogenic in fish and act as pure- or partial estrogen receptor alpha agonists. Reproductively mature fathead minnows (Pimephales promelas) were exposed to 0.002, 0.1, 1.2, 5.0 and 9.7 mg/L BP-2 for 15 days. Testes of exposed males had much fewer spermatocytes and ovaries of exposed females had much fewer mature and more atretic follicles. Reproduction was negatively affected in a dose-dependent manner with a decrease in egg production at 5.0 mg/L and a complete cessation of spawning activity at 9.7 mg/L BP-2. In other experiment, Xenopus laevis embryos were exposed in flow-through conditions to 0, 1.5, 3.0 or 6.0 mg/L BP-2 until 2 months post-metamorphosis. Concentration-dependent increases in severity of thyroid follicular cell hypertrophy and hyperplasia occurred in larval tadpoles indicating BP-2-induced impacts on the thyroid axis. Additionally, gonads were impacted in all treatments with some genetic males showing both testis and ovary tissues (1.5 mg/L) and 100% of the genetic males in the 3.0 and 6.0 mg/L treatments experiencing complete male-to-female sex reversal. Concentration-dependent vitellogenin induction occurred in both genders with associated accumulations of protein in the livers, kidneys and gonads, which was likely vitellogenin and other estrogen-responsive yolk proteins. BP-2 is a genotoxicant to corals, exhibiting a strong positive relationship between DNA-AP lesions and increasing BP-2 concentrations. BP-2 exposure in the light induced extensive necrosis in both the epidermis and gastro dermis. In contrast, BP-2 exposure in darkness induced autophagy and autophagic cell death.
Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro - in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data ... for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds.
/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Ketones and related compounds/
/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . For contamination, flush eyes immediately with water. Irrigate each eye continuously with with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . /Ketones and related compounds/
/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W TKO /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Ketones and related compounds/
在装配有搅拌器和氯化氢吸收系统的150 mL 三口烧瓶中,投入间苯二酚 1510 g (0.114 mol)、2, 4-二羟基苯甲酸 1514 g (0.11 mol)、无水 ZnCl₂ 2015 g (0.115 mol)、POCl₃ 3010 g (0.120 mol),以及溶剂环丁酮 15 mL。启动搅拌,将物料混合均匀,加热升温至70-75 ℃,保温反应2小时,直到吸收系统中很少有氯化氢气体放出为止。然后向反应瓶内缓慢加入水,搅拌直至完全溶解,再将其倒入800 mL 冷水中并充分搅拌。
A fluorescent probe which is represented by the following formula (I):
(wherein, R1 and R2 represent hydrogen atom, or a substituent for trapping proton, a metal ion, or an active oxygen species, or the like; R3 represents a monovalent substituent; R4 and R5 represent hydrogen atom or a halogen atom; R6 represents hydrogen atom, an alkylcarbonyl group, or an alkylcarbonyloxymethyl group, provided that a combination of R1, R2, and R3 provides (1) substantially high electron density of the benzene ring to which said groups bind, so that the compound represented by the formula (I) is substantially no fluorescent before the trapping of proton, or the like, and (2) substantially reduced electron density of the benzene ring to which said groups bind, so that a compound after the trapping, which is derived from the compound represented by the formula (I) is substantially highly fluorescent after the trapping of proton or the like). A fluorescent probe having an excellent fluorescence property is provided.
The present application relates to encapsulates, compositions, products comprising such encapsulates, and processes for making and using such encapsulates. Such encapsulates comprise a core comprising a perfume and a shell that encapsulates said core, such encapsulates may optionally comprise a parametric balancing agent, such shell comprising one or more azobenzene moieties.
The present invention relates to novel compounds of formula (I) wherein X, Q, R1, R2, R3, R4, R5, R6, R7, R8, R21, R22 and R23 are as defined herein. The compounds of formula (I) are inhibitors of telomerase enzyme function and are accordingly useful for the treatment cellular proliferation disorders, such as cancer.
Single‐Molecule Imaging of Active Mitochondrial Nitroreductases Using a Photo‐Crosslinking Fluorescent Sensor
作者:Zacharias Thiel、Pablo Rivera‐Fuentes
DOI:10.1002/anie.201904700
日期:2019.8.12
is activated sequentially by nitroreductases and light to give a photo‐crosslinked adduct of active enzymes. In combination with a general photoactivatable marker of mitochondria, we performed two‐color, three‐dimensional, single‐molecule localization microscopy. These experiments allowed us to image the sub‐mitochondrial organization of microdomains of nitroreductase activity.
A compound represented by the following Formula (1):
wherein, Het
1
represents a bivalent five- or six-membered aromatic heterocyclic residue and may further be substituted; X
a
to X
d
each independently represent a heteroatom and may further be substituted; Y
a
to Y
f
each independently represent a heteroatom or a carbon atom and may further be substituted; the ring bound to Het
1
may have a double bond at any position