Hosta

Isocoumarin (1H-2-benzopyran-1-one; 3,4-benzo-2-pyrone) is a lactone, a type of natural organic compound.

Known natural compounds

Hydrangenol
Phyllodulcin
Thunberginol C, D, E and G
The derivative 3-acetyl-3,4-dihydro-5,6-dimethoxy-1H-2-benzopyran-1-one can be found in Huáng bǎi (Phellodendron chinense), one of the fifty fundamental herbs of traditional Chinese medicine.^[1]

^ Cui, WS; Tian, J; Ma, ZJ; Guo, YQ; Wang, JH; Li, X (2003). "A new isocoumarin from bark of Pellodendron chinense". Natural Product Research. 17 (6): 427–9. doi:10.1080/14786410310001617695. PMID 14577693.

Types of isocoumarins
Aglycones	Bergenon Thunberginol A and B
Dihydroisocoumarins	Hydrangenol Mellein 6-Hydroxymellein 6-Methoxymellein Monocerin Phyllodulcin Thunberginol C, D, E and G