A New Diterpenoid from Aralia fargesii

Four diterpenoids, including a new ent-kaurane diterpene (1), were isolated from the rhizome of Aralia fargesii Franch. On the basis of chemical and spectral evidence (IR, EI-MS, HREI-MS, 1H-NMR, 13C-NMR and HMQC), the structure of compound 1 was established to be 17-acetoxy-16α-ent-kauran-19-oic acid. The other three known compounds were identified as ent-pimara-8(14),15-dien-19-oic acid (2), 16α-hydroxy-(-)-kauran-19-oic acid (3) and 16α-17-dihydroxy-ent-kauran-19-oic acid (4). The three known diterpenoids were obtained from this plant for the first time.