Metabolism of 2,2,4-trimethylpentane probably occurs by omega and omega-l oxidation to yield the corresponding alcohol and acid metabolites. While the exact structure of these remains to be elucidated, there is evidence that the cytochrome p450 system, lauric acid hydroxylases, and palmitoyl CoA oxidase in the liver and kidneys play a role in the biotransformation of 2,2,4-trimethylpentane. Studies indicate that 2,2,4-trimethylpentane (radiolabeled with (14)C) is metabolized by the cytochrome p450 system and that modulation of this enzyme system (with phenobarbital and metyrapone) will alter the disposition and renal retention of 2,2,4-trimethylpentane. Pretreatment of male rats with phenobarbital decreased the expired organics (from 40 to 10% of dose) and increased the urine radioactivity (from 46 to 80%), but did not alter the retention of radioactivity in the kidneys. Metyrapone (an inhibitor of cytochrome p450) increased the elimination half-life of expired 2,2,4-trimethylpentane (2.8 to 3.8 hr), did not alter urinary radioactivity, and decreased radioactivity retention in the kidney by 37%. From these studies, elimination of 2,2,4-trimethylpentane (isooctane) occurs mainly by metabolism to water-soluble products which are excreted in the urine and by exhalation of parent material.
Metabolic disposition of 2,2,4-trimethylpentane was studied in male and female rats. Rats were treated with a single oral dose of (14)C 2,2,4-trimethylpentane (4.4 mmol/kg; 2 uCi/mmol). Identification and quantitation of the urinary metabolites of 2,2,4-trimethylpentane showed that both male and female rats metabolize 2,2,4-tremethylpentane via the same pathway and at a similar rate. Female rats, however, excreted more conjugates of 2,4,4-trimethyl-2-pentanol in urine than males. 2,4,4-Trimethyl-2-pentanol was the major metabolite present in the male rat kidney, but was absent in the female rat kidney.
When (14)C 2,2,4-trimethylpentane was administered to an adult male Fischer-344 rat (300 mg/kg, ig) 22, 16, and 10 hr before sacrifice, 16% of the administered radioactivity was eliminated in the urine as 2,2,4-trimethylpentane metabolites.
来源:Hazardous Substances Data Bank (HSDB)
代谢
挥发性烃主要通过肺部吸收,也可能在吞咽后通过吸吮进入体内。
Volatile hydrocarbons are absorbed mainly through the lungs, and may also enter the body after ingestion via aspiration. (A600)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
毒性总结
石油馏分是中枢神经系统抑制剂,会导致肺部损伤。
Petroleum distillates are central nervous system depressants and cause pulmonary damage. (A600)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
2,2,4-三甲基戊烷存在于汽油中,可能对人类有致癌性(2B组)。
2,2,4-Trimethylpentane is found in gasoline, which is possibly carcinogenic to humans (Group 2B). (L135)
Petroleum distillates are aspiration hazards and may cause pulmonary damage, central nervous system depression, and cardiac effects such as cardiac arrhythmias. They may also affect the blood, immune system, liver, and kidney. (A600, L1297)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
暴露途径
该物质可以通过吸入和摄入被身体吸收。
The substance can be absorbed into the body by inhalation and by ingestion.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
Respiration is the most likely route by which 2,2,4-trimethylpentane is absorbed. Although it has not been determined, the respiratory uptake of 2,2,4-trimethylpentane is probably similar to that seen for n-octane. Oral absorption of (14)C-2,2,4-trimethylpentane has been reported ... to occur to the extent of 86% in male rats based on recovery of radioactivity in urine, expired organics, and expired (14)C-carbon dioxide. Dermal bioavailability has not been reported, but absorption of 2,2,4-trimethylpentane through the skin would be expected to be minor based on percutaneous results reported for n-heptane and n-octane. Oral gavage studies ... in male rats with (14)C-2,2,4-trimethylpentane (0.5 mg/kg, single dose) revealed that the radioactivity is selectively distributed in the kidneys 72 hr after administration. It has been suggested that the renal retention of 2,2,4-trimethylpentane is related to the hydrocarbon-induced nephropathy observed specifically in male rats.
Metabolic disposition of 2,2,4-trimethylpentane was studied in male and female Fischer 334 rats. Rats were treated with a single oral dose of (14)C 2,2,4-trimethylpentane (4.4 mmol/kg; 2 microCi/mmol). Radiolabeled material in kidney, liver, and plasma was determined at 4, 8, 12, 24, and 48 hr after dosing. Maximum concentration of 2,2,4-trimethylpentane derived radioactivity in kidney, liver, and and plasma of male rats was found after 12 hr (1252, 1000, and 403 nmol eg/g, respectively), whereas those measured in females were found after 8 hr (557, 1163, and 317 nmol eq/g, respectively). A selective retention of the 2,2,4-trimethylpentane derived radiolabel in the kidneys of male rats was noted when peak tissue concentration was expressed as a percentage of administered dose. Kidney concentrations of 2,2,4-trimethylpentane derived radiolabel increased in a nonlinear, but dose dependent radiolabel increased in a nonlinear, but dose-dependent, manner; the kidney to plasma ratio was greater at low doses than at higher doses. Increased retention of radiolabel material in the kidney was associated with a significant increase in renal concentration of the male rat specific protein, alpha 2u-globulin, 24 and 48 hr after 2,2,4-trimethylpentane administration. Total radioactivity collected in urine 48 hr after 2,2,4-trimethylpentane administration was similar in males and females (32 and 31% of dose). Identification and quantitation of the urinary metabolites of 2,2,4-trimethylpentane showed that both male and female rats metabolize 2,2,4-trimethylpentane via the same pathway and at a similar rate. Female rats, however, excreted more conjugates of 2,4,4-trimethyl-2-pentanol in urine than males. 2,2,4-Trimethyl-2-pentanol was the major metabolite present in the male rat kidney, but was absent in the female rat kidney. The renal retention of 2,4,4-trimethyl-2-pentanol appears to account for the delayed clearance observed in the disposition of (14)C 2,2,4-trimethylpentane derived radiolabel. Based on the concomitant accumulations in renal alpha 2u-globulin concentration and renal 2,4,4-trimethyl-2-pentanol concentration, an association is speculated between these two components. The male rat specific accumulation of 2,4,4-trimethyl-2-pentanol may therefore reflect the accumulation of a metabolite-alpha 2u-globulin complex. This may be relevant to the male-rat-specific nephrotoxicity produced by 2,2,4-trimethyl-pentane.
A study was conducted to determine if the rate of uptake and route of excretion of inhaled hydrocarbons and their metabolites might be different for branched alkanes relative to straight chain isomers. Male F344/N rats were exposed by nose only inhalation to nominal concentrations of 1 or 350 ppm (14)C labeled octane and isooctane for a period of 2 hours. Urine and feces were collected as were exhalants at 3, 6, 9, 18, 24, 30, 42, 54, and 66 hr post exposure. Exhalants were also collected at 1 and 2 hr post exposure. Elimination was most exclusively via the kidneys for isooctane while octane was eliminated about equally in urine and as exhaled carbon dioxide. Isooctane was excreted through the kidneys over the entire 70 hr, whereas octane excretion was essentially completed after 10 to 20 hr. At 70 hr after exposure about 5% of the octane equivalents inhaled at 1 ppm remained in the carcass. The author suggests that the different patterns of metabolites excretion of isooctane compared to octane may be a factor affecting the differences in nephrotoxicity between these two compounds.
Metal-free photoinduced C(sp3)–H borylation of alkanes
作者:Chao Shu、Adam Noble、Varinder K. Aggarwal
DOI:10.1038/s41586-020-2831-6
日期:2020.10.29
precious-metal catalysts for C-H bond cleavage and, as a result, display high selectivity for borylation of aromatic C(sp2)-H bonds over aliphatic C(sp3)-H bonds4. Here we report a mechanistically distinct, metal-free borylation using hydrogen atom transfer catalysis5, in which homolytic cleavage of C(sp3)-H bonds produces alkylradicals that are borylated by direct reaction with a diboron reagent. The reaction
Halogenated hydrocarbons and method for their preparation
申请人:DU PONT
公开号:US02440800A1
公开(公告)日:1948-05-04
Telomers are prepared by subjecting aliphatic mono-olefines and a substance YZ to elevated temperature and pressure in the presence of an ethylene polymerization catalyst. The substance YZ is defined as being free from aliphatic carbon-carbon unsaturation and capable of forming monovalent fragments Y and Z, one of which is an inorganic acid radicle and the other is either an inorganic acid radicle or a radicle containing carbon and which is (a) a halogen, e.g. chlorine, bromine and iodine; (b) a halogen containing carbon compound, e.g. chloriodoform, a -brompropionic acid, propyl trichloracetate, chloracetic anhydride, chlorpropionaldehyde, ethylene bromhydrin, glycerol a -monochlorhydrin, monochlormethyl ether, methyl chloride and chloracetyl chloride; (c) or compounds containing halogen in combination with an inorganic acid radicle, e.g. cyanogen chloride and bromide; (d) a sulphur halide, e.g. benzene sulphonyl chloride and sulphuryl chloride; (e) cyanogen; or (f) an ester of an inorganic acid, e.g. triethyl borate, tetraethyl silicate, tributyl phosphate and methyl sulphate. Suitable catalysts are oxygen, hydrogen, acetyl, benzoyl, diethyl and tetrahydronaphthalene peroxides, alkali ammonium persulphates, perborates and percarbonates, tetraethyl and tetraphenyl lead, ultra-violet light especially in the presence of photosensitizers such as mercury, alkyl iodides, benzoin and acetone, di-, tri-methylamine oxides dibenzoyl hydrazine, hydrazine hydrochloride and sebacate and hexachloroethane water solvents, e.g. isooctane, cyclohexane, benzene and dioxane, surface active agents, e.g. sodium acetoxyoctadecyl sulphate, buffers, and substances capable of forming interpolymers with olefines, e.g. vinyl compounds and unsaturated acids, esters and ketones may be present. Examples describe the telomerization of ethylene and carbon tetrachloride (1 to 5); chloroform (6 to 7); methylene chloroiodide (8); chloral hydrate (9); 1,1,1-trichloroethane (10); ethyl dichloroacetate (11); dichloroacetic acid (12); hexachloroethane (13); tetra- and pentra-chloroethylbenzenes (14); hexachlorobenzene (15); trichlorofluoromethane (16); dimethyl sulphate (17); ethyl orthosilicate (18); sulphuryl chloride (19); ethyl iodide (20); a ,a 1-dichloro-dimethyl ether (25); isobutylene and carbon tetrachloride (21); ethylene carbon tetrachloride and n-octene-1 (22), styrene (23); and vinyl chloride (24). The products may contain pure compounds, e.g. of the type Cl(CH2.CH2)nCCl3, where n is an integer. They may be used as solvents, heat transfer media, plasticisers, wax substitutes, coating materials and as additions to lubricating oils. Specifications 471,590, 497,643, 578,584 and 581,900 are referred to.
Elimination of nitrous acid is the exclusive reaction path for the thermal decomposition of the nitroalkanes 1, 2 and 5. Homolytic CC-cleavage cannot compete. A concerted β-elimination is the favoured mechanism.
SUBSTITUTED CARBAMOYLCYCLOALKYL ACETIC ACID DERIVATIVES AS NEP
申请人:KARKI Rajeshri Ganesh
公开号:US20120122764A1
公开(公告)日:2012-05-17
The present invention provides a compound of formula I;
or a pharmaceutically acceptable salt thereof, wherein R
1
, R
2
, R
3
, R
4
, R
5
, B, X, m and n are defined herein. The invention also relates to a method for manufacturing the compounds of the invention, and its therapeutic uses. The present invention further provides pharmaceutical composition of compounds of the invention, and a combination of pharmacologically active agents and a compound of the invention.
Oxidations by the reagent “O2–H2O2–vanadium derivative–pyrazine-2-carboxylic acid’. Part 12. Main features, kinetics and mechanism of alkane hydroperoxidation†
作者:Georgiy B. Shul’pin、Yuriy N. Kozlov、Galina V. Nizova、Georg Süss-Fink、Sandrine Stanislas、Alex Kitaygorodskiy、Vera S. Kulikova
DOI:10.1039/b101442k
日期:——
Various combinations of vanadium derivatives (n-Bu4NVO3 is the best catalyst) with pyrazine-2-carboxylic acid (PCA) catalyse the oxidation of saturated hydrocarbons, RH, with hydrogen peroxide and air in acetonitrile solution to produce, at temperatures <40 °C, alkyl hydroperoxides, ROOH, as the main primary products. These compounds are easily reduced with triphenylphosphine to the corresponding alcohols
钒衍生物的各种组合(n -Bu 4 NVO 3是最好的催化剂),用吡嗪-2-羧酸(PCA)催化饱和烃RH的氧化,用过氧化氢和空气在乙腈溶液中的氧化,在<40°C的温度下生成烷基氢过氧化物ROOH作为主要催化剂农产品。这些化合物容易被三苯基膦还原成相应的醇,然后可以通过GLC定量测定。某些类似于PCA的氨基酸可以起到助催化剂的作用;但是,吡啶甲酸和咪唑-4,5-二羧酸的氧化速率和最终产物收率较低,而咪唑-4-羧酸和吡唑-3,5-二羧酸几乎没有活性。羟基自由基对烷烃RH的攻击引起氧化,从而产生烷基R 4。后者进一步与分子大气中的氧迅速反应。这样形成的过氧自由基ROO 3可以转化为氢过氧化物烷基。根据对环己烷氧化的动力学研究,我们得出结论,反应的限速步骤是含有一个配位PCA分子的复合物的单分子分解:VV(PCA)(H 2 O 2)→V IV(PCA)+HOO˙+ H +。在V IV由此物种发生反应形成进一步与第二H