36455-70-6Relevant articles and documents
Determination of the conformation of E and Z zearalenone and their 7α- and 7β-hydroxy congeners
Gelo,Raza,Sunjic,Guo,Snatzke
, p. 1005 - 1010 (1991)
The CD spectra of some resorcylic acid macrocyclic lactones (RAL) are reported. The spectra of the E,Z-isomeric ketones 1,6 are very similar in shape and magnitude. The Cotton effects of the 7α-alcohols 2 and 7 are also of the same shape, but the Δε values of 7 are only ca. 50% of those of the others. The E-7β-ol 3 gives a completely different CD, whereas in the Z-series 8 shows a similar CD curve as 6 and 7, but with again reduced magnitude. The CDs of the acetates 4 and 5 are very similar to those of the corresponding alcohols 2 and 3, resp. The effect of the 7α- and 7β-hydroxy or acetoxy group on the absolute conformation of the 'chain' from C(5) to C(10) is thus transmitted to the absolute value of the torsional angle of the inherently chiral chromophore C(11)-C(12)-C(12a)-C(1a)-C(=O)O in 2,3 and 4,5, resp. The CD spectra of the E,Z-isomers do not exhibit straightforward correlation with the configuration around the C=C double bond.
In vitro phase i metabolism of cis -zearalenone
Drzymala, Sarah S.,Herrmann, Antje J.,Maul, Ronald,Pfeifer, Dietmar,Garbe, Leif-Alexander,Koch, Matthias
, p. 1972 - 1978 (2015/02/19)
The present study investigates the in vitro phase I metabolism of cis-zearalenone (cis-ZEN) in rat liver microsomes and human liver microsomes. cis-ZEN is an often ignored isomer of the trans-configured Fusarium mycotoxin zearalenone (trans-ZEN). Upon the influence of (UV-) light, trans-ZEN isomerizes to cis-ZEN. Therefore, cis-ZEN is also present in food and feed. The aim of our study was to evaluate the in vitro phase I metabolism of cis-ZEN in comparison to that of trans-ZEN. As a result, an extensive metabolization of cis-ZEN is observed for rat and human liver microsomes as analyzed by HPLC-MS/MS and high-resolution MS. Kinetic investigations based on the substrate depletion approach showed no significant difference in rate constants and half-lives for cis- and trans-ZEN in rat microsomes. In contrast, cis-ZEN was depleted about 1.4-fold faster than trans-ZEN in human microsomes. The metabolite pattern of cis-ZEN revealed a total of 10 phase I metabolites. Its reduction products, α- and β-cis-zearalenol (α- and β-cis-ZEL), were found as metabolites in both species, with α-cis-ZEL being a major metabolite in rat liver microsomes. Both compounds were identified by co-chromatography with synthesized authentic standards. A further major metabolite in rat microsomes was monohydroxylated cis-ZEN. In human microsomes, monohydroxylated cis-ZEN is the single dominant peak of the metabolite profile. Our study discloses three metabolic pathways for cis-ZEN: reduction of the keto-group, monohydroxylation, and a combination of both. Because these routes have been reported for trans-ZEN, we conclude that the phase I metabolism of cis-ZEN is essentially similar to that of its trans isomer. As trans-ZEN is prone to metabolic activation, leading to the formation of more estrogenic metabolites, the novel metabolites of cis-ZEN reported in this study, in particular α-cis-ZEL, might also show higher estrogenicity.
