Antifungal activity ofEuphorbiaspecies against moulds responsible of cereal ear rots

Aims This work aimed to identify secondary metabolites from aerial parts ofEuphorbiaspecies functional for control of toxigenicFusariumspecies responsible of cereal grain rots. Methods and Results Aerial parts ofEuphorbia serpens,Euphorbia schickendantziiandEuphorbia collinawere sequentially extracted with hexane, ethyl acetate and methanol. The extracts were tested against strains ofFusarium verticillioidesandFusarium graminearumby microdilution tests. The hexane extract ofE. collinaprovided the lowest IC(50)s on both fungal species. Further fractionation showed that cycloartenol (CA) and 24-methylenecycloartanol are associated to the moderate inhibitory effect of the hexane extract on fungal growth.Sublethal concentrations of CA and 24MCA blocked deoxynivalenol (DON) and fumonisins production.CA and 24MCA co-applied with potassium sorbate, a food preservative used forFusariumcontrol, synergized the growth inhibition of fungi. The mixtures reduced mycotoxins accumulation when applied at sublethal concentrations. Conclusions CA and 24MCA inhibited both fungal growth and mycotoxins production. This fact is an advantage respect to potassium sorbate which increased the mycotoxins accumulation at sublethal concentrations. Significance and Impact of the Study CA and 24MCA synergized potassium sorbate and their mixtures offer a lower mycotoxigenic risk than potassium sorbate for control of theFusariumspecies.

Automated summary

The study found that cycloartenol and 24-methylenecycloartanol extracted from aerial parts of Euphorbia species can inhibit the growth and mycotoxin production of Fusarium species, and when combined with potassium sorbate, they are more effective in reducing mycotoxin accumulation. This suggests that the mixtures offer a lower mycotoxigenic risk compared to potassium sorbate alone for controlling Fusarium species.