Bitter taste perception cautions humans against the ingestion of potentially toxic compounds. However, current knowledge about natural bitter substances and their activation of human bitter taste receptors (TAS2Rs) is biased toward substances from flowering plants, whereas other sources are underrepresented. Although numerous mushrooms taste bitter, the corresponding substances and receptors are unexplored. Three previously undescribed triterpene glucosides, named oligoporins D-F, together with the known oligoporins A and B, were isolated from