Preparative Enzymatic Synthesis of Glucuronides of Zearalenone and Five of Its Metabolites

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• 作者：David E. Stevenson ; Richard P. Hansen ; Jared I. Loader ; Dwayne J. Jensen ; Janine M. Cooney ; Alistair L. Wilkins ; Christopher O. Miles
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2008
• 出版时间：June 11, 2008
• 年：2008
• 卷：56
• 期：11
• 页码：4032 - 4038
• 全文大小：737K
• 年卷期：v.56,no.11(June 11, 2008)
• ISSN：1520-5118

文摘

The resorcylic acid lactones zearalenone (1), α-zearalenol (2), β-zearalenol (3), α-zearalanol (zeranol) (4), β-zearalanol (taleranol) (5), and zearalanone (6) were converted to their glucuronides on a preparative scale in good yields. Reactions were conducted with bovine uridine 5′-diphosphoglucuronyl transferase (UDPGT) as catalyst and uridine 5′-diphosphoglucuronic acid (UDPGA) as cofactor. The glucuronides were isolated by column chromatography and characterized by NMR spectroscopy and mass spectrometry. Although the principal products were 4-O-glucuronides (i.e., linkage through a phenolic hydroxyl), significant quantities of the 6′-O-glucuronides (i.e., linkage through the aliphatic hydroxyl) of alcohols 2, 4, and 5 were also isolated. In the case of 3, the 2-O-glucuronide was isolated as the minor product. Overall isolated yields of glucuronides, performed on a 20−50 mg scale, were typically ca. 80% based on the resorcylic acid lactone starting material. LC-UV-MS² analysis of purified specimens revealed MS² fragmentations useful for defining the point of attachment of the glucuronide moiety to the zearalenone nucleus.