126
four p-menthane derivatives (866, 867, 868, and 871), a guaiane-type sesquiterpenoid (782), and a neolignan (1048) were isolated from sample 4 [240, 274]. The
configurations of C-7 and C-8 were determined as threo by
1
H NMR spectroscopic
coupling constant analysis.
3.14 Ligularia rumicifolia S. W. Liu
Several bicyclic eremophilane, oplopane, and bisabolane compounds were isolated
from L. rumicifolia (Table 17). Many of these types of compounds were obtained
from sample 1 (Lhasa, Tibet Autonomous Region, China) [75]. Thus, ten bicyclic
eremophilanes with a 9-en-8-one moiety, namely, petasol (48), rumicifoline K (53),
petasin (54), rumicifoline J (57), 1-epi-rumicifoline J (58), 60, 63, rumicifoline L
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
OH
O
O
OH
O
OH
OH
O
O
O
O
O
O
O
O
O
759
760
761
762
7 63
764
765
7 66
767
7 68
769
7 70
771
758 ((–)-germacrene D)
OH
O
O
O
OAc
O
O
O
OH
O
O
O
OAc
O
O
O
OH
O
OH
Fig. 51 Germacrane-type sesquiterpenoids
M. Tori and C. Kuroda