Search

Concern about the risk of exposure to emerging plant-derived mycotoxins such as beauvericin and enniatins has been addressed by the European Commission who requested the European Food Safety Authority for a scientific opinion on their risk to human and animal health. The studied mycotoxins were found in feeds with enniatin B and beauvericin at average concentrations of 19.9 μg/kg and 30 μg/kg, respectively. In all cases, concentrations of all the mycotoxins analyzed were below quantification limits (, AQUAEXCEL 2020 (652831) under TNA project AE050057: “Implications for aquaculture of non-regulated emerging mycotoxins” granted to J. Nácher-Mestre

Publisher Summary This chapter discusses the structure of and microbiological activity in the Enniatin-series. The cyclic depsipeptide is built up by regularly alternating D-α-hydroxyisovaleric acid and a N-methyl-amino-acid, which in Enniatin A is N-methyl- L-isoleucine and in Enniatin B N-methyl- L-valine. The tertiary butyl ester of D-α-hydroxy-isovaleric acid is coupled by means of benzene sulfochloride to the corresponding benzyloxycarbonyl-amino-acid in the presence of pyridine. By enlarging the decarbobenzoxylated tetradepsipeptide ester used in the Enniatin B synthesis with the didepsipeptide acid containing L-valine, the hexadepsipeptide for the monodesmethyl-product can be obtained. The synthetic route to the tridesmethyl-enniatin B resembles the one used for the synthesis of the Enniatin B, differing only by the use of L-valine instead of N-methyl- L-valine.

The present state of the chemistry of the valinomycin type and enniatin B type depsipeptide ionophores is reviewed. An analysis is carried out on the relation between the primary structure, the conformation, the complexing properties, and the membrane activity of valinomycin and its numerous analogs. The correlations resulting from such a study have made it possible to carry out the predetermined synthesis of valinomycin analogs excelling the parent compound in complexing properties.