Antifungal acylcyclopentenediones from fruiting bodies of hygrophorus chrysodon

Chrysotriones A (1) and B (2), two new 2-acylcyclopentene-1,3-dione derivatives, were isolated from the fruiting bodies of the Basidiomycete Hygrophorus chrysodon, and their structures were established by spectroscopic data and synthesis of compound 2. They represent the first examples of 2-acylcyclopentene-1,3-diones found in mushrooms and suggest an unprecedented biosynthetic pathway, starting from fatty acid derivatives. Initial tests indicated interesting antifungal activity of chrysotriones against Fusarium Verticillioides, one of the common worldwide pathogens of cultivated plants. In our search for new prototype bioactive agents from higher mushrooms (Basidiomycetes),1 we examined the chemical contents of Hygrophorus chrysodon (Batsch.: Fr.) Fr. (Hygrophoraceae).2 This is an ectomycorrhizal fungal species, growing solitary, scattered to gregarious in mixed conifer-hardwood woods, in particular in the presence of Fagus trees, and fruiting from late fall to mid-winter. It is easily recognized by a white, viscid cap and stipe, both decorated with golden yellow granules, hence the ancient Greek name “chrysodon”, and by widely spaced, waxy, white decurrent gills. Our field observations indicated that fruitin