In vitro inhibitory effect of tetrahydrocurcuminoids on Fusarium proliferatum growth and Fumonisin B1 biosynthesis

Véronique Coma (1) , Elise Portes (1) , Christian Gardrat (1) , Florence Richard-Forget (2) , Alain Castellan (1)

1 UB - Université Sciences et Technologies - Bordeaux 1
2 MycSA - Unité de recherche Mycologie et Sécurité des Aliments

Many plant-pathogenic often produce toxic metabolites when grow on foods and feeds. Some antioxidative components seemed to prevent fungi growth and mycotoxin formation. Recently, we had synthezised a new class of powerful antioxidative compounds, i.e. tetrahydrocurcuminoids, and structure/antioxydant activity relationships had been established. The South West of France is known to produce large amounts of corn, which can be infested by Fusarium species, and particularly F. proliferatum. In this context, the efficiency of tetrahydrocurcuminoids, which can be obtained from natural curcuminoids, was investigated to control in vitro the growth of F. proliferatum and the production of its associated mycotoxin fumonisin B1. The relation between structure and antifungal activity was particularly studied. Tetrahydrocurcumin THC1, with two guaiacyl phenolic subunits, showed the highest inhibitory activity (measured as the radial growth on agar medium) against the F. proliferatum development (67% inhibition at a concentration of 13.6 μmol.mL-1). The efficiencies of THC2 (36% at a concentration of 11.5 μmol.mL-1), which contains syringyl phenolic units and THC3 (30% at a concentration of 13.6 μmol.mL-1), which does not have any substituent on the aromatic rings were relatively close. These results indicate that the simultaneous presence of guaiacyl phenols and the enolic function of the β-diketone moiety play an important role in the inhibition mecanisms. The importance of this combination was confirmed by using n-propylguaiacol and acetylacetone as molecular models. In the same conditions, ferulic acid and eugenol, other natural phenolic antioxidants, were less efficient in inhibiting fungal growth. THC1 also reduced fumonisin B1 production in liquid medium by approximately 35%, 50%, and 75% at concentrations of 0.8, 1.3, and 1.9 μmol.mL-1, respectively. These very low inhibitory concentrations show that tetrahydrocurcuminoids could be one of the most promising biobased molecules for the control of mycotoxinogen fungal strains.

Mots clés: Life Sciences

Domaines: Sciences du Vivant [q-bio]; Ingénierie des aliments; Génie des procédés

Véronique Coma, Elise Portes, Christian Gardrat, Florence Richard-Forget, Alain Castellan. In vitro inhibitory effect of tetrahydrocurcuminoids on Fusarium proliferatum growth and Fumonisin B1 biosynthesis. Food Additives and Contaminants, 2011, 28 (2), pp.218. ⟨10.1080/19440049.2010.540721⟩. ⟨hal-00660032⟩