Structures of six new compounds from Ligularia brassicoides

Four new eremophilane type sesquiterpenoids, a new bakkane type sesquiterpenoid, and a new secoeremophilane type sesquiterpenoid were isolated from Ligularia brassicoides Hand.-Mass. (Asteraceae) collected in China, and were an epoxy lactone derived from 6-acyloxyeuryopsin 1, 6-acyloxy-9-oxoeuryopsin 2, 6-acyloxy-9-oxofuranoeremophilane 3, 6-acyloxyeuryopsin 4, 6-acyloxy bakkane type epoxy lactone 5, and secovirgaurenol 6-O-(2′-hydroxymethyl)acrylate (6), respectively. All but one had a 2′-hydroxymethylacryloyloxy group at C-6. This is the first study to describe the chemical constituents of this species.     

Eremophilane,bakkane, secoeremophilane,and secobakkane sesquiterpenoids from Ligularia virgaurea collected in China

Secobakkane B (C-6/C-7 cleaved secobakkane type aldehyde), secovirgaurenols B and C (C-8/C-9 cleaved secoeremophilane type), a 1β,10β-epoxyfuranoeremophilane, two 1β,10β-epoxyeremophilanolides, and fukinospirolide C (bakkane-type lactone), as well as 33 known compounds were isolated from three samples of Ligularia virgaurea collected in China. Two of the three analyzed samples were grouped in the neoadenostylone (N) type, and the rest, a mixture of the 6-hydroxyeuryopsyn (H) and cacalol (C) types, out of five chemotypes found in this species.