METABOLISM OF 2-METHYLNAPHTHALENE IN THE RAT INVIVO .1. IDENTIFICATION OF 2-NAPHTHOYLGLYCINE

  • 1 January 1982
    • journal article
    • research article
    • Vol. 10  (2) , 128-133
Abstract
Urine was collected from 4 female rats for 3 days after 2 s.c. injections with 0.3 mg of 2-methyl[8-14C]naphthalene/kg. Of the 14C injected, 55% was found in the urine. The urine was solvent-fractionated into a toluene fraction (4.9% of urine 14C), a chloroform fraction (11.7%), 2 ethyl acetate fractions (41.7%) and a methanol fraction (37.8%). Only .apprx. 3-5% of urine 14C was unchanged 2-methylnaphthalene. A major radioactive peak which was isolated from the chloroform fraction was further subdivided into 3 peaks by HPLC [high performance liquid chromatography]. These metabolites, which may be 3 isomeric dihydrodiols of 2-methylnaphthalene, represented 6-8% of urine 14C. The more polar fractions contained several radioactive peaks when examined by TLC. One peak was hydrolyzed with base to Gly and a 14C-labeled material which was similar to 2-naphthoic acid by TLC and by HPLC. Mass spectrometry of this latter material and of the unhydrolyzed metabolite confirmed the presence of 2-naphthoic acid and 2-naphthoylglycine, respectively. 2-Naphthoylglycine accounted for 30-35% of urine 14C.