5-ETHYL-5-PHENYLHYDANTOIN N-GLUCURONIDE, THE MAJOR URINARY METABOLITE OF 5-ETHYL-5-PHENYLHYDANTOIN (NIRVANOL) IN THE DOG

  • 1 January 1982
    • journal article
    • research article
    • Vol. 10  (6) , 595-598
Abstract
A water-soluble metabolite, isolated from the urine of dogs given (S)-5-ethyl-5-phenylhydantoin [(S)-EPH], was identified as 1-deoxy-1-[(5S)-5-ethyl-5-phenylhydantoin-3-yl] .beta.-D-glucopyranuronate [S)-EPH N-glucuronide]. EPH N-glucuronide did not release the aglycone upon acid or .beta.-glucuronidase treatment, but incubation in alkaline solution (pH 12-13) readily formed 2-ethyl-2-phenylhydantoic acid (EPHA). The EPHA could be quantitatively cyclized to EPH. Knowing the conversion efficiency of EPH N-glucuronide to EPHA, a quantitative GLC assay for the metabolite was developed. EPH N-glucuronide was the major urinary metabolite after administration to dogs of either (R)-, (S)-, or (RS)-EPH.