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Preparative enzymatic synthesis of glucuronides of zearalenone and five of its metabolites

Abstract
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.
Type
Journal Article
Type of thesis
Series
Citation
Stevenson, D. E., Hensen, R. P., Loader, J. I., et al. (2008). Preparative enzymatic synthesis of glucuronides of zearalenone and five of its metabolites. Journal of Agricultural and Food Chemistry. 56(11), 4032-4038.
Date
2008
Publisher
American Chemical Society
Degree
Supervisors
Rights