Identification of the main metabolites of 2-ethylhexanoic acid in rat urine using gas chromatography-mass spectrometry.
The metabolites of 2-ethylhexanoic acid, an industrial chemical and the active ingredient in wood preservatives, were investigated in rat urine. Male Wistar rats were given 2-ethylhexanoic acid (2-EHA) in drinking water (600 mg/kg daily) for nine weeks, and then urine specimens were collected and analysed. The compounds were identified by gas chromatography-mass spectrometry in both electron-impact mode and chemical ionization mode. In addition to 2-EHA, ten different 2-EHA-related metabolites were found in the urine of 2-EHA-treated rats. The main metabolite was 2-ethyl-1,6-hexanedioic acid. Urine also contained 2-ethyl-6-hydroxyhexanoic acid and five other hydroxylated metabolites and two lactones, the detailed structures of which have not yet been elucidated. The unsaturated 5,6-dehydro-EHA was also identified; this is the metabolite corresponding to 2-n-propyl-4-pentenoic acid, the hepatotoxic metabolite of valproic acid. At least part of the 2-EHA is present in urine as a glucuronide conjugate.
Pennanen
S
S
National Public Health Institute, Department of Environmental Hygiene and Toxicology, Kuopio, Finland.
Auriola
S
S
Manninen
A
A
Komulainen
H
H
D000818:Animals; D002208:Caproates / Q000378:metabolism / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D002208:Caproates; C040668:2-ethylhexanoic acid