Abstract
Protective and curative antifungal activities of 16 1-[1-(2-substituted hydroxy-5-substituted phenyl)vinyl]imidazoles and 9 1-[2-(2-substituted hydroxy-5-substituted phenyl)-allyl]imidazoles were measured against Botrytis cinerea, a phytopathogenic fungus, under greenhouse conditions. A relationship between their antifungal activity in greenhouse conditions and that in vitro was examined quantitatively based on the regression analysis with the aid of physicochemical and structural parameters. The higher the in vitro activity, the higher the protective activity in greenhouse conditions. The protective activity was more persistent in the vinylimidazoles than in the corresponding allylimidazoles. The curative activity in greenhouse conditions increased as the activity in vitro increased. Substitution of the 2, 6-dichlorobenzyloxy group at the 2-position on the benzene ring was favorable to the curative activity. The curative activity does not seem to depend on the hydrophobicity of the molecule, because the positive effect of the log P term on the in vitro activity and the negative effect on the mobility within the leaf cancel each other.
