Ovine Metabolism of Zearalenone to α-Zearalanol (Zeranol)

This is the first report of a metabolic conversion in animals of zearalenone to zearalanols. Zearalenone was labeled with deuterium by base-catalyzed isotope exchange. The labeled zearalenone, in the form of its β-cyclodextrin inclusion complex, was administered orally and intravenously to sheep. In addition to deuteriozearalenone glucuronide, analysis of the urine revealed the presence of deuteriated α- and β-zearalenol and α- and β-zearalanol glucuronides. No zearalanone was detected in the urine. The problem of cis−trans isomerization of zearalenone in the presence of sunlight is also discussed. Keywords: Zeranol; zearalanol; zearalenone; zearalenol; metabolism; residue; Fusarium; mycotoxin