Zearalenone treatment

The influence of zearalenone on the generative development of winter rape was much weaker in comparison with that of wheat. None of the concentrations which stimulated wheat plants induced the flowering of rape plants. Zearalenone treatment stimulated only the first step of the process of the shoot apices generative differentiation (Biesaga-Koscielniak 2001). 

Biesaga-KoScielniak J, Marcinska I, W dzony M, KoScielniak J (2003) Effect of zearalenone treatment in the production of wheat haploids via maize pollination system. Plant Cell Rep 21 1035-1039... 

Zearalenone was also found to be more effective than cytokinin treatment in inducing shoots in in vitro winter wheat production. Moreover, both zearalenone and cytokinins increased the activity of antioxidant enzymes in wheat callus undergoing regeneration, and it is very likely that they also stimulated the plant regeneration process (Szechynska-Hebda et al. 2007). The effectiveness of regeneration on media containing zearalenone shows the possibility of using zearalenone as an alternative hormone also to cytokinins in winter wheat callus culture. 

Zearalenone is an estrogenic mycotoxin that usually causes toxicity in swine that consume contaminated corn. Prepubertal swine are mostly affected. Affected females show swelling of the vulva and excessive straining, which may cause vaginal prolapses. In male animals, zearalenone will cause decreased libido. There is no effective treatment apart from withdrawing the feed containing the mycotoxin. 

The final step in the synthesis of DL-zearalenone (2) involved removal of the protecting groups of the dimethyl ether (I). Treatment with boron trifluoride etherate or... 

Scheme 51), Weavers utilized direct formation of the a-iodomethylene-y-butyrolactone 148 from the propiolate 147 via atom transfer cyclization. Alke-noyloxymethyl iodides and selenides were converted into lactones upon treatment with tributylstannane or tributylgermane [101], In the (—)-zearalenone (152) synthesis reported by Pattenden [102] (Scheme 52), the ester tether is a bystander in the radical macrocyclization. 

Masamune has made use of this property for synthesis of medium ring lactones (macrolides), for example, zearalenone dimethyl ether ethylene ketal (5) from the hydroxy ester (4). On treatment with mercuric trifluoroacetate at 25°, (4) is converted within 5 min. into the lactone (5) in >90% yield (recrystalhzed). 

Mercuric trifluoroacetate [Hg(OCOCF3)2] is an effective reagent for the cyclization of hydroxy thio-esters. 5 This cyclization procedure was used by Masamune et al. for the conversion of 225 to 227 (in 90% yield) in a synthesis of zearalenone dimethyl ether. Masamune developed this procedure to complete the total synthesis of methymycin, where one step involved treatment of a thioester with mercuric salts. 2,96 Mercury(II) has an affinity for bivalent sulfur and it binds the thioester unit as well as the terminal hydroxyl... 

In addition, DalTErta et al. described the stability of D3G and two zearalenone conjugates upon digestion by application of an in vitro assay that simulated human digestion. In particular, the salivary step (5 min), the gastric step (120 min) and the duodenal step (120 min) were mimicked, performing various sequential enzymatic treatments. 

Heat treatment of contaminated materials decreases mycotoxin concentrations in many cases. Aflatoxins are especially thermostable and a significant decrease in their content occurs at temperatures of about 200 °C. Ergot alkaloids and zearalenone are also very stable at high temperatures. 

---