Isolation and identification of a novel isomerized epoxide metabolite of FK-506 from erythromycin-induced rabbit liver microsomes

Drug Metab Dispos. 1993 Sep-Oct;21(5):850-4.


A novel metabolite of FK-506-a C13, C15, C31 O-demethyl C19 hydroxymethyl C36 isomerized epoxide of FK-506 obtained from erythromycin-induced rabbit liver microsomes--was isolated by HPLC and identified by FAB/MS and NMR. The existence of ring-chain tautomers for this metabolite is demonstrated by NMR spectroscopy. FAB/MS, and HPLC.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Chromatography, High Pressure Liquid
  • Enzyme Induction
  • Epoxy Compounds / analysis
  • Epoxy Compounds / isolation & purification*
  • Erythromycin / pharmacology*
  • Isomerism
  • Magnetic Resonance Spectroscopy
  • Male
  • Microsomes, Liver / drug effects*
  • Microsomes, Liver / enzymology
  • Microsomes, Liver / metabolism*
  • Oxidation-Reduction
  • Rabbits
  • Spectrometry, Mass, Fast Atom Bombardment
  • Tacrolimus / metabolism*


  • Epoxy Compounds
  • Erythromycin
  • Tacrolimus