Four New ent-Kaurane Diterpenoids from the Fruits of Annona cherimola

摘要

Four new ent -kaurane diterpenoids (16 R )- ent -kauran-17,19-diol (1), (16 R )-17-hydroxy- ent -kauran-19-oic acid (2), (16 S )-17-hydroxy- ent -kauran-19-oic acid (3), and (16 R )-17-dimethoxy- ent -kauran-19-oic acid (4) have been isolated from the fresh fruits of Annona cherimola together with eight known compounds. Their structures are determined on the basis of spectroscopic data and optical rotation.