Ethylene dibromide (1,2-dibromoethane, EDB) is metabolized by two routes: a conjugative route catalyzed by glutathione S-transferases (GST) and an oxidative route catalyzed by cytochrome P450 (P450). The GST route is associated with carcinogenicity. An approach is presented to use human purified GST and P450 enzymes to explore the importance of these metabolic pathways for man in vivo. This strategy basically consists of four steps: (i) identification of the most important isoenzymes in vitro, (ii) scaling to rate per milligram cytosolic and microsomal protein, (iii) scaling to rate per gram liver, and (iv) incorporation of data in a physiologically based pharmacokinetic (PBPK) model. In the first step, several GST isoenzymes were shown to be active toward EDB and displayed pseudo-first-order kinetics, while the EDB oxidation was catalyzed by CYP2E1, 2A6, and 2B6, which all displayed saturable kinetics. In the second step, the predictions were in agreement with the measured activity in a batch of 21 human liver samples. In the third step, rat liver P450 and GST metabolism of EDB was predicted to be in the same range as human metabolism (expressed per gram). Interindividual differences in GST activity were modeled to determine "extreme cases." For the most active person, an approximately 1.5-fold increase of the amount of conjugative metabolites was predicted. Lastly, it was shown that the GST route, even at low concentrations, will always contribute significantly to total metabolism. In the fourth step, a PBPK model describing liver metabolism after inhalatory exposure to EDB was used. The saturation of the P450 route was predicted to occur faster in the rat than in man. The rat was predicted to have a higher turnover of EDB from both routes. Nevertheless, when all data are combined, it is crucial to recognize that the GST remains significantly active even at low EDB concentrations. The limitations and advantages of the presented strategy are discussed.
Urinary metabolites in rats and mice after oral administration of ethylene dibromide were identified as S-(2-hydroxyethyl)cysteine and N-acetyl-s-(2-hydroxyethyl)cysteine; N-acetyl-s-(2-hydroxyethyl)cysteine-s-oxide was also identified after ip admin of the chemical.
In vivo studies indicated that reaction /between EDB and glutathione/ occurs primarily in liver with formation of S-(beta-hydroxyethyl)glutathione, S-(beta-hydroxyethyl)glutathione sulfoxide and S,S1-bis(glutathione)ethylene. Later degradation occurs primarily in kidneys to yield S-(beta-hydroxyethyl) mercapturic acid and its sulfoxide.
The metabolism of halogen-containing fumigants in mammals (and birds) ... reviewed. An explanation for efficient prodn of S-(2-hydroxyethyl)glutathione from ethylene dibromide prodn in liver prepn probably depends on ... reactivity of the product ... of the first displacement reaction, which is a 'sulfur mustard' derivative. The derived episulfonium ion is very reactive towards nucleophilic attack, hydrolysis yielding S-(2-hydroxyethyl)glutathione & reaction with another molecule of glutathione giving ... ethylene SS'-bisglutathione.
来源:Hazardous Substances Data Bank (HSDB)
代谢
1_2-二溴乙烷的人类代谢物包括2-溴乙醛。
1_2-dibromoethane has known human metabolites that include 2-bromoacetaldehyde.
IDENTIFICATION AND USE: Ethylene dibromide (1,2-Dibromoethane) is a colorless liquid. Historically, the primary use of 1,2-dibromoethane has been as a lead scavenger in antiknock mixtures added to gasolines. Another major past use of 1,2-dibromoethane was as a pesticide and an ingredient of soil and grain fumigants and for post-harvest application. 1,2-Dibromoethane has been used as a chemical intermediate in the manufacture of resins, gums, waxes, dyes, and pharmaceuticals and as a high-density, nonflammable solvent. HUMAN STUDIES: 1,2-Dibromoethane has produced oral ulcerations, followed by liver and renal toxicity. Cases of fatal poisoning have been reported. It was a DNA damaging agent when tested in human lymphocytes, but positive results were noted only after metabolic activation. ANIMAL STUDIES: Dogs exposed for 1 to 1.5 hr to vapor of 1,2-dibromoethane developed clouding of corneas several hours after removal from the exposure chamber. Rats tolerated exposure to 25 ppm 1,2-dibromoethane in air over 7 hr/day for 151 days, but 63 similar exposures to levels of 50 ppm were lethal to 20-50% of animals. Deaths from acute exposure were usually due to lung congestion and hemorrhage although liver and kidney damage, as well as corneal injury, were also observed. 1,2-Dibromoethane caused tumors in rats and mice at several different tissue sites and by several different routes of exposure. Inhalation exposure to 1,2-dibromoethane caused cancer of the nasal cavity and the blood vessels in rats of both sexes and in female mice; benign or malignant lung tumors in mice of both sexes and in female rats; and benign or malignant mammary gland tumors in females of both species. It also caused testicular tumors in male rats and cancer of the subcutaneous tissue in female mice. Dermal exposure to 1,2-dibromoethane caused lung and skin tumors in female mice. In mice, administration of 1,2-dibromoethane in the drinking water caused forestomach tumors in both sexes and benign tumors of the esophagus in females. Some of the male reproductive effects of ethylene dibromide in the human have been modelled in the rabbit, although the rabbit appears not to be as sensitive, since semen parameters were affected only at doses close to the LD50 (55 mg/kg). When given ip at dose of 10 mg/kg on 5 successive days to rats it damaged spermatogenic cells. Two to three weeks after start of oral treatment of bulls with 4 mg/kg bw 1,2-dibromoethane on alternate days, abnormal spermatozoa were observed, indicating interference with spermatogenesis and with maturation of spermatozoa in epididymis. Fetal abnormalities were observed when pregnant rats and mice were exposed at 31.6 ppm 1,2-dibromoethane for 23 hr a day during the 6th-15th days of gestation. 1,2-Dibromoethane bound covalently to liver DNA of rats treated in vivo. It was selectively lethal to DNA-repair-deficient bacteria, and provoked DNA repair in cultured mammalian cells. It was mutagenic to bacteria, fungi, vascular plants, insects and cultured mammalian cells in the absence of an exogenous metabolic activation system. It induced chromosomal aberrations and sister chromatid exchanges in cultured mammalian cells. ECOTOXICITY STUDIES: 1,2-Dibromoethene showed low toxicity to most aquatic species tested. It was phytotoxic for green plants and germinating seed.
The metabolite 2-bromoacetaldehyde produces liver damage by binding to cellular proteins. S-(2-bromoethyl)glutathione, another metabolite, exerts genotoxic and carcinogenic effects by binding to DNA. Antispermatogenic effects of 1,2-dibromoethanes metabolites may be caused by their covalent binding to thiol groups of nucleoproteins in nuclei of spermatozoa. Such adduct formation interferes with DNA, causing improper packing of the chromatin. (L120)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌性证据
癌症分类:B2组可能的人类致癌物
Cancer Classification: Group B2 Probable Human Carcinogen
CLASSIFICATION: "likely to be carcinogenic to humans". BASIS FOR CLASSIFICATION: This is based on the consistent findings of several studies reporting increased incidences of a variety of tumors in rats and mice of both sexes by different routes of administration at both the site of application and at distant sites, it can be concluded that there is strong evidence of the carcinogenicity of 1,2-dibromoethane in animals. The available evidence further supports a conclusion that 1,2-dibromoethane is a genotoxic carcinogen based on evidence from a variety of in vitro and in vivo test systems. HUMAN CARCINOGENICITY DATA: Inadequate. ANIMAL CARCINOGENICITY DATA: Sufficient.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌性证据
A3:已确认的动物致癌物,对人类的相关性未知。
A3: Confirmed animal carcinogen with unknown relevance to humans.
/Ethylene dibromide is/ ... readily & rapidly absorbed from lung when breathed as vapor, GI tract when taken by mouth, or through skin when applied topically. ... Distribution of bromide in the tissues /reported/. ...
After ip admin of (14)C-ethylene dibromide to guinea pigs (30 mg/kg), greatest concn of (14)C was found in those tissues in which pathological changes ... reported (kidneys, liver & adrenals). 65% Of dose was excreted as metabolites in urine & 12% unchanged in expired air.
Twenty-four hr after ip admin of 40 mg/kg body wt (14)C-ethylene dibromide to mice, 40% was excreted as metabolites in the urine, and 15% ... accounted for in the body tissues, incl 6% in the blood. The highest activity per gram of tissue, excepting the blood, was found in the kidney and stomach (incl stomach contents).
After admin ip injections of (14)C-ethylene dibromide to rats and mice ... cmpd was widely distributed, with concn in liver, kidney, & small intestine. At 24 hr the liver and kidney contain irreversibly bound (14)C in RNA, DNA, and protein.
Compositions for Treatment of Cystic Fibrosis and Other Chronic Diseases
申请人:Vertex Pharmaceuticals Incorporated
公开号:US20150231142A1
公开(公告)日:2015-08-20
The present invention relates to pharmaceutical compositions comprising an inhibitor of epithelial sodium channel activity in combination with at least one ABC Transporter modulator compound of Formula A, Formula B, Formula C, or Formula D. The invention also relates to pharmaceutical formulations thereof, and to methods of using such compositions in the treatment of CFTR mediated diseases, particularly cystic fibrosis using the pharmaceutical combination compositions.
Synthesis and biochemical activities of antiproliferative amino acid and phosphate derivatives of microtubule-disrupting β-lactam combretastatins
作者:Niamh M. O'Boyle、Lisa M. Greene、Niall O. Keely、Shu Wang、Tadhg S. Cotter、Daniela M. Zisterer、Mary J. Meegan
DOI:10.1016/j.ejmech.2013.01.016
日期:2013.4
The synthesis and biochemical activities of novel water-soluble β-lactam analogues of combretastatin A-4 are described. The first series of compounds investigated, β-lactam phosphate esters 7a, 8a and 9a, exhibited potent antiproliferativeactivity and caused microtubule disruption in human breast carcinoma-derived MCF-7 cells. They did not inhibit tubulin polymerisation in vitro, indicating that biotransformation
[EN] SUBSTITUTED N-HETEROCYCLIC CARBOXAMIDES AS ACID CERAMIDASE INHIBITORS AND THEIR USE AS MEDICAMENTS<br/>[FR] CARBOXAMIDES N-HÉTÉROCYCLIQUES SUBSTITUÉS UTILISÉS EN TANT QU'INHIBITEURS DE LA CÉRAMIDASE ACIDE ET LEUR UTILISATION EN TANT QUE MÉDICAMENTS
申请人:BIAL BIOTECH INVEST INC
公开号:WO2021055627A1
公开(公告)日:2021-03-25
The invention provides substituted N-heterocyclic carboxamides and related compounds, compositions containing such compounds, medical kits, and methods for using such compounds and compositions to treat a medical disorder, e.g., cancer, lysosomal storage disorder, neurodegenerative disorder, inflammatory disorder, in a patient.
Synthesis, characterization, catalytic and biological application of half-sandwich ruthenium complexes bearing hemilabile (κ2-<i>C</i>,<i>S</i>)-thioether-functionalised NHC ligands
作者:Weiguang Chen、Julien Egly、Amalia I. Poblador-Bahamonde、Aline Maisse-Francois、Stéphane Bellemin-Laponnaz、Thierry Achard
DOI:10.1039/c9dt04825a
日期:——
suggesting that the only species observed by the 1H-NMR correspond to an average resonance position of a fluxional mixtures of isomers. All these complexes were found to catalyse the oxydant-free double dehydrogenation of primary amine into nitrile. Ru complexbearing NHC-functionalised S-tBu group was further investigated in a wide range of amines and was found more selective for alkyl amine substrates than
Compounds of the formula:
are useful in treating disease conditions mediated by TNF-&agr;, such as rheumatoid arthritis, osteoarthritis, sepsis, AIDS, ulcerative colitis, multiple sclerosis, Crohn's disease and degenerative cartilage loss.