Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Record number 409492
Title Bioassay based screening of steroid derivatives in animal feed and supplements
Author(s) Rijk, J.C.W.; Ashwin, H.M.; Kuijk, S.J.A. van; Groot, M.J.; Heskamp, H.H.; Bovee, T.F.H.; Nielen, M.W.F.
Source Analytica Chimica Acta 700 (2011)1-2. - ISSN 0003-2670 - p. 183 - 188.
Department(s) Rikilt B&T Toxicologie en Effectanalyse
RIKILT B&T Authenticiteit en Nutrienten
Laboratory for Organic Chemistry
RIKILT - R&C Groeibevorderaars
Publication type Refereed Article in a scientific journal
Publication year 2011
Keyword(s) testosterone-undecanoate - liquid-chromatography - androgen bioassay - yeast bioassay - validation - urine
Abstract Receptor binding transcription activation bioassays are valuable tools for the screening of steroid hormones in animal feed and supplements. However, steroid derivatives often lack affinity for their cognate receptor and do not show any direct hormonal activity by themselves. These compounds are thus not detected by these kinds of bioassays and need a bioactivation step in order to become active, both in vivo and in vitro. In this study a comparison was made between different in vitro activation methods for hormone esters and hormone glycosides. Testosterone acetate and testosterone decanoate were chosen as model compounds for the hormone esters, representing the broad range of steroid esters of varying polarities, while genistin was used as a substitute model for the steroid-glycosides. Concerning bioactivation of the steroids esters, the efficiency for alkaline hydrolysis was 90–100% and much better as compared to enzymatic deconjugation by esterase. As a result 1 µg testosterone ester per gram of animal feed could easily be detected by a yeast androgen bioassay. When comparing different enzyme fractions for deglycosilation, genistin was shown to be deconjugated most efficiently by ß-glucuronidase/aryl sulfatase from Helix pomatia, resulting in a significant increase of estrogenic activity as determined by a yeast estrogen bioassay. In conclusion, chemical and enzymatic deconjugation procedures for ester and glycoside conjugates respectively, resulted in a significant increase in hormonal activity as shown by the bioassay readouts and allowed effective screening of these derivatives in animal feed and feed supplements.
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