6-Ethyl-3- urinary metabolites

The major urinary metabolite of di(2-ethylhexyl) adipate, 2-ethylhexanoic acid, has been shown to be an appropriate marker for biological monitoring of dietary di(2-ethylhexyl) adipate intake (Loftus etal., 1993, 1994). A limited population study in the United Kingdom was undertaken to estimate the daily intake of di(2-ethylhexyl) adipate following intake of a mean dose of 5.4 mg di(2-ethylhexyl) adipate presented with food. The study involved the determination of the urinary metabolite, 2-ethyl-hexanoic acid (24-h mine sample) in 112 individuals from five geographical locations. A skewed distribution with a median value for the daily intake of 2.7 mg was determined (Loftus et al., 1994). This value is about one third of the indirectly estimated maximum intake of 8. 2 mg per day. The probability of a daily intake in excess of 8.2 mg in the limited population (112 individuals) was calculated to be 3% (Loftus etal, 1994). 

A half-life of 6 min for metabolism of di(2-ethylhexyl) adipate has been determined in rat small intestinal mucous membrane homogenates. The dominant urinary metabolite of di(2-ethylhexyl) adipate (500 mg/kg bw) in male Wistar rats is adipic acid, which accoimts for 20-30% of the administered oral dose. The other major metabolite which was found only in the stomach is mono(2-ethylhexyl) adipate (Takahashi et al., 1981). In cynomolgus monkeys, the glucuronide of mono(2-ethyl-hexyl) adipate and traces of unchanged di(2-ethylhexyl) adipate were foimd in the urine (BUA, 1996). 

EME and BEG, which is mainly obtained by enzymatic hydrolysis, represents respectively the 32-49 % and 29 45 % of total urinary metabolites cocaine can be converted, in small amounts, to norcocaine (NCOC) and psychoactive metabolite norbenzoylecgonine (NBE). The combined intake of alcohol and cocaine determines the formation of a pharmacologically active metabolite, the cocaethylene (ethyl ester of benzoylecgonine, CE), with a significant liver toxicity [13],... 

A. Fidder, D. Noort, L.P.A. de Jong, H.P. Ben-schop and A.G. Hulst, N7-(2-Hydroxyethylthio-ethyl)-guanine a novel urinary metabolite following exposure to sulfur mustard, Arch. Toxicol., 70, 854-855 (1996). 

MS data for certain steroids and their TMS ethers in order to study the neutral urinary metabolites of the anabolic steroid 17a-ethyl-17j3-hydroxy-4-en-3-one by GC—MS. 

Disposition in the Body. Rapidly absorbed after oral or parenteral administration and metabolised by V-dealkylation to V-ethyl-nicotinamide and nicotinamide rapidly excreted in the urine the major urinary metabolite is V-ethylnicotinamide. 

Taber, D. F., Teng, D. Total Synthesis of the Ethyl Ester of the Major Urinary Metabolite of Prostaglandin E2. J. Org. Chem. 2002, 67, 1607-1612. 

Urethane can be excreted in the urine unchanged (0.5-1.7% of dose). Urethane can also be metabolized by the liver cytochrome P450 system. The urinary metabolites of urethane include N-hydroxy urethane, acetyl-N-hydroxyurethane, ethyl mercapt-uric acid, and N-acetyl-S-ethoxycarbonyl cysteine. 

AM Treston, WD Hooper. Urinary metabolites of phenobarbitone, primidone, and their N-methyl and N-ethyl derivatives in humans. Xenobiotica 22 385, 1992. 

Paracetamol (acetaminophen) was synthesised first in 1888 as an intermediate in the synthesis of phenacetin. Unfortunately, the organic chemists at Bayer never tested this compoimd for its medicinal properties. The prevailing thought at the time was that phenols were too toxic for clinical use. It was the Swedish physiological chemist, Karl Morner in 1891 who discovered that paracetamol (acetaminophen) was a urinary metabolite of phenacetm. This is a result of the 0-de-ethylation of phenacetin... 

The oral toxicity in animals was found to be low to very low. An LD50 value of 3500 mg/kg for rats has been documented (NIOSH 1986). No adverse effects were noted in animals subjected to chronic inhalation exposure at below 400 ppm. At higher dosages only the liver was affected (ACGIH 1986). Ethyl benzene is eliminated from the body by metabolic excretion. The urinary metabolites in humans are mainly mandelic acid, C6HsCH(OH)COOH, and benzoyl-formic acid, CeHsCOCOOH. 

Urinary metabolites VMA and HVA The metabolites are present in urine at much higher concentrations than the catecholamines - 10-50 pmoll . They are readily extracted from acidified urine into ethyl acetate which can then be evaporated off and the residue dissolved in the mobile phase of choice. VMA is only weakly retained on C18 columns and... 

Urinary Metabolites of 2-Ethyl-2-methylsuccinimide (Ethosuximide) Studied by Combined Gas Chromatography-Mass Spectrometry Biomed. Mass Spectrom. 5(11) 601-603 (1978) CA 91 13384g... 

P. Husek, P. Matucha, P. Simek, Smooth Esterification of Di and Tricarboxylic Acids with Methyl and Ethyl Chloroformates in Gas Chromatographic Profiling of Urinary Acidic Metabolites, Chromatographia, 58, 623 630 (2003). 

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