Ambuic acid, a highly functionalized cyclohexenone with antifungal activity from Pestalotiopsis spp. and Monochaetia sp.

Ambuic acid, a highly functionalized cyclohexenone, was isolated and characterized from Pestalotiopsis spp. and Monochaetia sp. these being biologically related endophytic fungi associated with many tropical plant species. This compound was found in representative isolates of these fungal species obtained from rainforest plants located on several continents. The relevance of ambuic acid to the biology of the association of these fungi to their host plants is also discussed.