363
Views
24
CrossRef citations to date
0
Altmetric
Original Articles

Preparation and characterization of the conjugated Fusarium mycotoxins zearalenone-4O-β-D-glucopyranoside, α-zearalenol-4O-β-D-glucopyranoside and β-zearalenol-4O-β-D-glucopyranoside by MS/MS and two-dimensional NMR

, , , , , , & show all
Pages 207-213 | Received 21 May 2008, Accepted 08 Aug 2008, Published online: 05 Feb 2009
 

Abstract

Glucosides of several Fusarium mycotoxins occur in naturally infected cereals and may contribute to an increased content to the total mycotoxin load of food and feed. The paper presents the results of a fermentation procedure to produce zearalenone-4O-β-D-glucopyranoside from zearalenone using an engineered Saccharomyces cerevisiae strain, expressing the Arabidopsis thaliana UDP-glucosyltransferase UGT73C6. About 24 mg of zearalenone-4O-β-D-glucopyranoside was obtained from 50 mg of zearalenone and further purified. A total of 10 mg of the glucoside were reduced with sodium borohydride, yielding 4.1 mg α-zearalenol-4O-β-D-glucopyranoside and 4.5 mg β-zearalenol-4O-β-D-glucopyranoside at purities higher than 99%. To confirm the identities of the three produced glucosides, MS and MS/MS spectra were acquired using negative electrospray ionization. Besides the deprotonated ions at m/z 479 or 481, respectively, in full-scan mode, fragments, adducts, and dimers were recorded and assigned. MS/MS spectra of the glucosylated substances yielded the deprotonated ions of the mycotoxins zearalenone, α-zearalenol, β-zearalenol and their fragments, respectively. Unambiguous structural assignment of the three substances was achieved using two-dimensional NMR methods. This way, the glucose attachment to position C-4, the β-configuration of the sugar unit and the stereo-chemical assignment of the zearalenol hydroxyl group at C-6′ were proven.

Acknowledgements

The authors thank the Christian Doppler Society, the Austrian Science Fund (FWF Project No. L225-B11), and the UK Food Standards Agency for financial support.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.