Phenolic compounds from the cultured mycobionts of Graphis proserpens

► Spore-derived mycobionts of the lichen Graphis proserpens were cultivated. ► Six compounds were isolated from the cultures and their structures were determined. ► Three isocoumarins were closely related to fungal metabolites. ► Proserins possessed a unique 7-oxo-5,7-dihydrooxepino[4,3,2-de]isochromene skeleton.