83
C-10 position. Bohlmann et al. reported the chemical constituents of sample 2 collected in Munich (Germany) [13]. Thus, two norsesquiterpenoids, ligujapone (123),
liguhodgsonal (125), and four hydrocarbons (758, 812 (major constituent), 875, and
883) were documented. Three norsesquiterpenoids (111, 113 (major constituent),
115), and the 3,6,10-trioxygenated eremophilanolide 429 were reported from sample 3, obtained from Dali (Yunnan Province, China) [90]. The configuration of the
6,7-epoxide of 113 was assigned as α, but without discussing any supportive
evidence.
3.4 Ligularia hookeri (C. B. Clarke) Handel-Mazzetti
Ligularia hookeri grows on glassy slopes, forest understories, stream banks, scrubland, and alpine meadows, at altitudes of about 3000–4500 m (Plate 7) [2]. Four
specimens, collected in 2002 and 2003 from Sichuan Province, China (Table 7,
sample 1), were combined and analyzed to characterize the four purified eremophilanes, 215, 220, 221, and 223, with the last-mentioned compound as the
major constituent [138]. The chemical constituents of sample 2 were found to be
slightly different, as constituted by the 15-oic acid 209, the epimers 213 and 214,
the 15,6-lactone 223, a bisabolane (650), and a eudesmane (790). It is interesting to
note that the C-15 carbon atoms of all these compounds isolated from L. hookeri are
oxidized to a carboxylic acid or a lactone. The previously proposed 6α-H configuration for the related compounds 222 and 224 by Bohlmann and Knoll [287] was
revised to 6β-H [138]. For this species, no distinct variations were found among the
two samples examined (Table 7).
Table 6 Samples 1–3 of L. japonica and their chemical constituents
No.
Collection
year
Collection
place
Bicyclic
eremophilanes
10-OH Tricyclic
eremophilanes
Others
Ref.
1
a
(Japan)
−
226, 227, 231
−
[12,
286]
2
1977
München
(Germany)
123, 125
−
758, 812,
875, 883
[13]
3
a
Dali (Y)
111, 113, 115
429
−
[90]
a Not described
Chemical Constituents of Ligularia Species (Asteraceae) and Their Diversity…
C-10 position. Bohlmann et al. reported the chemical constituents of sample 2 collected in Munich (Germany) [13]. Thus, two norsesquiterpenoids, ligujapone (123),
liguhodgsonal (125), and four hydrocarbons (758, 812 (major constituent), 875, and
883) were documented. Three norsesquiterpenoids (111, 113 (major constituent),
115), and the 3,6,10-trioxygenated eremophilanolide 429 were reported from sample 3, obtained from Dali (Yunnan Province, China) [90]. The configuration of the
6,7-epoxide of 113 was assigned as α, but without discussing any supportive
evidence.
3.4 Ligularia hookeri (C. B. Clarke) Handel-Mazzetti
Ligularia hookeri grows on glassy slopes, forest understories, stream banks, scrubland, and alpine meadows, at altitudes of about 3000–4500 m (Plate 7) [2]. Four
specimens, collected in 2002 and 2003 from Sichuan Province, China (Table 7,
sample 1), were combined and analyzed to characterize the four purified eremophilanes, 215, 220, 221, and 223, with the last-mentioned compound as the
major constituent [138]. The chemical constituents of sample 2 were found to be
slightly different, as constituted by the 15-oic acid 209, the epimers 213 and 214,
the 15,6-lactone 223, a bisabolane (650), and a eudesmane (790). It is interesting to
note that the C-15 carbon atoms of all these compounds isolated from L. hookeri are
oxidized to a carboxylic acid or a lactone. The previously proposed 6α-H configuration for the related compounds 222 and 224 by Bohlmann and Knoll [287] was
revised to 6β-H [138]. For this species, no distinct variations were found among the
two samples examined (Table 7).
Table 6 Samples 1–3 of L. japonica and their chemical constituents
No.
Collection
year
Collection
place
Bicyclic
eremophilanes
10-OH Tricyclic
eremophilanes
Others
Ref.
1
a
(Japan)
−
226, 227, 231
−
[12,
286]
2
1977
München
(Germany)
123, 125
−
758, 812,
875, 883
[13]
3
a
Dali (Y)
111, 113, 115
429
−
[90]
a Not described
Chemical Constituents of Ligularia Species (Asteraceae) and Their Diversity…