Effect of amphiphilic antioxidant alkyl ammonium ascorbate on inhibition of fungal growth: Application to wood preservatives formulation
C Gérardin , T Koumbi Mounanga, P Gérardin
Amphiphilic surfactants were synthesized from ascorbic acid and different fatty amines and evaluated for formulation of wood preservation products. Characterization of physicochemical properties of the new compounds indicated classical behavior of cationic surfactants. Antioxidant properties, estimated using methyl linoleate oxidation inhibition method, were similar to that of ascorbic acid tested in the same conditions. Growth inhibition assays indicated that amphiphilic dodecylammonium ascorbate is able to inhibit Coriolus versicolor mycelium development, while butylammonium ascorbate deprived of surfactant properties has no effect. This compound was then investigated in the formulation of wood preservation mixtures containing propiconazole and compared to formulation obtained with an industrial surfactant. Biological tests based on the ability of these formulations to protect beech wood blocks exposed to a white rot fungus Coriolus versicolor were carried out under laboratory conditions. Results indicated that use of propiconazole formulation in aqueous solution allows to reduce the quantity of biocide compared to solutions of the same concentrations in ethanol. Protection achieved with antioxidant surfactant
was slightly superior to that conferred by conventional surfactant.