Zearalenone

• ZEA
• ZON
• F2 - toxin
• (3S, 11E ) -14.16 -dihydroxy-3 -methyl-7 -oxo- benzoxacyclotetradec - 11 -en- 1-one

White solid

Fixed

187-189 ° C

• Soluble in acetone and ethanol
• Practically insoluble in water

Risk

Template: Infobox chemical / molecular formula search available

Zearalenone ( ZEA or abbreviated ZON ) is a widespread mycotoxin. It belongs to the group of substances of Fusarium toxins. Chemically, it is ( resorcinol - α - carboxylic acid derivative) to be construed as macrolide and resorcylic derivative, so it is a macrocyclic lactone. The biosynthesis is via a polyketide pathway.

Occurrence

Zearalenone is produced by several species of the ubiquitous genus Fusarium. Relevant is the presence of the toxin in crops that were infested with F. graminearum or F. culmorum - especially corn, wheat, barley and Others cereal. Zearalenone is always accompanied in the affected plants of mycotoxins of the trichothecene group of like deoxynivalenol.

Properties

Zearalenone is a white, crystalline substance. It is thermally and chemically stable enough to be content in contaminated food either by storage or by preparation ( cooking, baking ) is substantially reduced.

Use

A variety of derivatives zearalenone were synthesized and tested for their pharmacological activity. Use is as the α - zearalanol called 6 - ( 6,10- dihydroxy -undecyl ) - β - resorcylsäurelacton, resulting from zearalenone by reduction of the double bond and the keto group, as growth promoters in cattle. This use is banned in the EU since 1989.

Biological Significance

Zearalenone acts as an estrogen. Its binding affinity to estrogen receptors is approximately ten to twenty fold lower than that of the 17- β - estradiol, but its half-life is considerably longer. A steady intake through diet leads to hyperestrogenism with all its symptoms and consequences: Size and weight gain of the uterus, disruption of the menstrual cycle, pathological changes in the ovaries, false pregnancies, abortions and sterility. These effects occur particularly in pigs and humans, while cattle in chickens hardly effects are less affected and observe.

There is also reason to believe that zearalenone is the reason for the occurrence of early pubertal changes in children. Due to its estrogenic action, it has an effect on tumor formation hormonally sensitive tissues ( see, e.g., breast cancer).

The estrogenic activity of zearalenone is enhanced by its metabolism further: In the body done a reductive remodeling, which leads via the reduction of the keto group and the double bond to four different derivatives ( including the above α - zearalanol ), which are predominantly significantly more effective.

Safety

Zearalenone is of only low acute toxicity (LD50 (mouse, oral) > 2000 mg / kg LD50 ( rat, oral) > 10000 mg / kg). These values ​​can not be achieved through the ingestion of contaminated food de facto. Due to the effect of estrogen and a TDI ( tolerable daily intake, tolerable daily intake ) of 0.2 g / kg by the Scientific Committee on Food of the European Commission, it was decided. Legal limits for zearalenone are dietetic foods for infants and young children at 20 micrograms / kg for cereals at 50 mcg / kg and especially for cereals for the production.