Of zearalenone

Farmed animals tend to be subjected to compounds that can be classified more easily as drugs. In some cases, animals may encounter compounds in nature that have considerable limitations in inclusion in the diets of farmed animals. An example is the inclusion of zearalenone (Figure 1) and its derivatives in animal diets these have anabolic and oestrogenic properties " and are permitted to be used in some areas of the world but are prohibited from use in others, such as European Union countries. Thus this compound and its reduced isomers (zearalenols, zeranols) improve growth rates in animals but can cause reproductive problems, especially in pigs. Ralgro, which is a commercially prepared derivative of zearalenone, is used as an ear implant in beef cattle as a growth promoter in... 

An intramolecular variant of the Stille coupling is suitable for the construction of macrocycles. An example is the ring-closing step to form a 14-membered lactone ring 8 in a synthesis of zearalenone as reported by Stille et al. ... 

In spite of the fact that contamination of cereals and grains and related products with mycotoxins causes food and feed-bome intoxications in man and livestock, zearalenone in low concentrations can be treated as a plant hormone which influences the development and yield of crop plants (Biesaga-Koscielniak 2001). This review focuses on the effect of low doses of zearalenone on the stimulation of selected physiological processes in plants important for agriculture production. 

UV absorption maxima occur at 236, 274 and 316 nm. The molecular formula of zearalenone is C18H22Os, its molecular weight is 318.4 g/mol and its melting point is 162-163°C (Blackwell et al. 1985 Josephs et al. 2003). The maximum fluorescence in ethanol occurs with irradiation at 314 nm and with emission at 450 nm. Its solubility in water is about 0.002 g/100 ml. In an aqueous solution of inositol, the presence of zearalenone can change the crystal structure of this alcohol, which indicates the possibility of interaction between both substances (our observations). Moreover, zearalenone is slightly soluble in hexane and progressively more so in benzene, acetonitrile, methylene chloride, methanol, ethanol and acetone. However, it is readily soluble in aqueous alkali. 

In fungal cultures a number of closely related metabolites are formed, but there is only limited evidence that these occur in foodstuffs, although there is experimental evidence for some transmission of zearalenone and a- and P-zearalenols into the milk of sheep, cows and pigs fed with these substances at high concentrations. Zearalenone does not degrade at high temperatures (Zinedine et al. 2007), but may... 

Because estrogenic mycotoxins usually occur at microgram per kilogram (pg/kg) levels there is special interest in analytical procedures for reliable detection of zearalenone and its metabolites between 10 and 100 pg/kg. In response to the risk of a great economic loss to the industry and the threat to human health as a result of exposure to zearalenone, several methods have been developed for the quantification of zearalenone and its metabolites in different foods, feeds, animal tissues, blood and urine. Detailed reviews have been given by Steyn et al. 1991 Betina 1993 Frisvad and Thrane 1993 Scott 1993 Steyn 1995 and Lawrence and Scott 2000. The determination of zearalenone in cereals can be divided into five steps grinding of the sample, extraction of the sample, clean-up, separation and detection. 

In this regard several sophisticated chromatographic methods, with a quantification limit down to about 0.2 ng/g, have been developed and published for the determination of zearalenone. The methods were mainly based on high-performance liquid chromatography (HPLC) with fluorescence detection (Krska 1998 Visconti and Pascale 1998 Schuhmacher et al. 1998 Tanaka et al. 2000), but HPLC with mass spectrometry detection was also used (Shirai et al. 2000 Josephs et al. 2001). 

Another method which uses capillary electrophoresis with laser-induced fluorescence detection can also be employed to detect zearalenone (Maragos and Appell 2007). In order to analyse trace amounts of zearalenone in plants, a sensitive, quick and accurate method, the enzyme-linked immunosorbent assay (ELISA) was developed by Chen et al. 1989. 

The endogenous existence of zearalenone in plants served as a spur to further studies and its identification in different species. Han and Meng (1986) found zearalenone in rape, Meng et al. (1986) in winter wheat, Li and Meng (1989) in Apium gaveoleus, Que et al. (1990) in cotton, Han and Meng (1991) in Lemna... 

Table 15.1 The influence of zearalenone on the generative development of winter wheat cv. Grana after various periods of vernalization (According to Biesaga-Koscielniak 1998, modified). Isolated wheat embryos were cultured in sterile conditions on Murashige and Skoog (1962) media supplemented with 0 (control), 0.25, 0.50, 0.75 and 2.00 mg/dm3 of zearalenone during 14, 28 and 42 days at 5°C (vernalization). After these periods, plants were transferred to soil and cultivated at 20/17°C. Number of headed plants, generative development of apexes and number of vegetative ones was obtained after 100 days of grown at 20/17°C...

Concentration of zearalenone (mg/dm3) Number of plants Generative Headed (non-headed) Vegetative Differentiation of frequency with respect to control... 

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). 

Table 15.4 The influence of the inhibitor of zearalenone (malathion) on the generative development of winter wheat plants. Seeds of wheat cv. Grana were cultured at sterile condition on Murashige and Skoog (1962) media supplemented with 0 (control), melathion (10 ml/dm3) and zearalenone (2 mg/dm3) during 5 weeks at 5°C (optimal time of vernalization). After vernalization plants were replaced to soil and grown at 20/17°C. Percentage of headed plants and the length of phase from vernalization to flowering was determined for 100 plants in each kind of medium...

The effect of zearalenone on crop development may be connected to its influence on the status and functioning of the photosynthetic apparatus (Koscielniak et al. 2008). The after-effects of zearalenone on the growth of soybean and wheat plants, net photosynthesis and transpiration rates, stomatal conductance, photochemical efficiency of photosystem 2 and on final seeds yield were determined. Modifications in leaf area were more pronounced in soybean than in wheat, and this tendency increases in successive developmental phases. The net photosynthesis was stimulated during the juvenile phase and during that of the final one by about 13.6% (average) in soybean plants. Stimulation of transpiration was also observed after... 

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... 

Fu YF, Li HY, Meng FJ (1995) The possible role of zearalenone in the floral gradient in Nicotiana tabacum L. J Plant Physiol 147 197-202... 

Javier LU, Marazuela MD, Moreno-Bondi MC (2007) Molecularly imprinted polymers applied to the clean-up of zearalenone and a-zearalenol from cereal and swine feed sample extracts. Anal Bioanal Chem 385 1155-1161... 

Li HX, Meng FJ (1989) Isolation and identification of zearalenone from Apium gaveoleus. Acta BotSin 12 211-215... 

Meng FJ, Que YM, Han YZ, Li HX, Wang ZC (1989) Isolation of zearalenone from shoot apices of overwintering winter wheat. Sci China 32 1009-1105 (Chinese, Engl, summ.)... 

Mirocha CJ, Schauerhamer B, Pathre SV (1974) Isolation, detection, and quantification of zearalenone in maize and barley. J Assoc Anal Chem 57 1104-1110 Muller R, Baier M, Kaiser WM (1991) Differential stimulation of PEP-carboxylation in guard cells and mesophyll cells by ammonium or fusicoccin. J Exp Bot 42 215-220 Murashige T, Skoog F (1962) A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol Plant 15 473-497... 

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