199
192]. Compounds 787 and 788 are aromadendrane-type sesquiterpenoids, which
have been isolated from Ligularia plants only rarely.
Ligularia franchetiana (H. Léveillé) Handel-Mazzetti (sample 3 from Yunnan
Province) produced franchetianones A and B (633 and 193) as well as
eremophila- 1(10),11-diene (1) [19]. Franchetianone A (633) is a bakkane-type sesquiterpenoid bearing a carbonyl group at the C-9 position. A carbonyl group at C-9
was also found in franchetianone B (193), a furanoeremophilane.
Ligularia persica Boissier was collected in Tehran (Iran) (sample 4), and its
chemical constituents included fukinone (4), 211, 212, 344, bakkenolide A (629),
789, 791, and eight germacrane-type sesquiterpenoids (760–767) [39]. Tenmembered carbocyclic rings are flexible, and it is especially important to pay attention to the epoxide configurations in these as well as to draw the representative
stereochemistry without any ambiguity. Germacranes have not been isolated frequently from Ligularia species, but they occur quite often in members of the genus
Eupatorium.
The Finnish L. speciosa Fischer et Meyer (sample 5) (also termed L. speciosa
(Schrader ex Link) Fischer & C. A. Meyer and L. fischeri (Ledebour) Turczaninow
[2]) was investigated by Bohlmann et al. to obtain isofukinone (7), petasol (48),
neopetasol (49), 2-hydroxyplatyphillide (121), liguhodgsonal (125), methyl ferulate (931), 940, 943, 947, euparin (952), 954, 652, (−)-germacrene D (758), and
(E,E)-α-farnesene (878) [43]. Fukinone and petasol-type compounds have a double bond at C-9/C-10, but isofukinone (7) has a double bond at C-1/C-10. The
cytotoxic peroxide 652 has been found only infrequently as a constituent of
Ligularia species.
Two reports on the constituents of L. thyrsoidea (Ledebour) de Candolle (samples
6 and 7) were reported, one from Bohlmann and Ziesche (1980) [131] and the other
by Jia’s group (1999) [233] (Sect. 3.13). Interestingly, they proved to be quite different from each other. The German sample 6 afforded furanoeremophilan-15-oic acid
195 as the major constituent, in addition to two 15-oxygenated furanoeremophilanes
(211 and 213), two germacratrienes (758 and 759), and two hydrocarbons (878 and
883). In turn, the Chinese sample 7 accumulated five bisabolane derivatives (709,
710, 711, 712, and 713) [233]. These results suggest that there is some chemical
diversity for this species, although additional samples are required to be examined.
3.39 Further Ligularia Species II: L. achyrotricha (Diels)
Y. Ling, L. nanchuanica S. W. Liu, L. purdomii (Turrill)
Chittenden, L. odontomanes Handel-Mazzetti, L. sibirica
(Linnaeus) Cassini, and L. thomsonii
(C. B. Clarke) Pojarkova
Ligularia achyrotricha (Diels) Y. Ling (sample 8 from Gansu Province, China) produced 11 aromatic compounds, which were, in turn, 925, 982, 983, 984, 989, 990,
991, 992, 1039, 1040, and 1042 (Table 47) [261].
Chemical Constituents of Ligularia Species (Asteraceae) and Their Diversity…
192]. Compounds 787 and 788 are aromadendrane-type sesquiterpenoids, which
have been isolated from Ligularia plants only rarely.
Ligularia franchetiana (H. Léveillé) Handel-Mazzetti (sample 3 from Yunnan
Province) produced franchetianones A and B (633 and 193) as well as
eremophila- 1(10),11-diene (1) [19]. Franchetianone A (633) is a bakkane-type sesquiterpenoid bearing a carbonyl group at the C-9 position. A carbonyl group at C-9
was also found in franchetianone B (193), a furanoeremophilane.
Ligularia persica Boissier was collected in Tehran (Iran) (sample 4), and its
chemical constituents included fukinone (4), 211, 212, 344, bakkenolide A (629),
789, 791, and eight germacrane-type sesquiterpenoids (760–767) [39]. Tenmembered carbocyclic rings are flexible, and it is especially important to pay attention to the epoxide configurations in these as well as to draw the representative
stereochemistry without any ambiguity. Germacranes have not been isolated frequently from Ligularia species, but they occur quite often in members of the genus
Eupatorium.
The Finnish L. speciosa Fischer et Meyer (sample 5) (also termed L. speciosa
(Schrader ex Link) Fischer & C. A. Meyer and L. fischeri (Ledebour) Turczaninow
[2]) was investigated by Bohlmann et al. to obtain isofukinone (7), petasol (48),
neopetasol (49), 2-hydroxyplatyphillide (121), liguhodgsonal (125), methyl ferulate (931), 940, 943, 947, euparin (952), 954, 652, (−)-germacrene D (758), and
(E,E)-α-farnesene (878) [43]. Fukinone and petasol-type compounds have a double bond at C-9/C-10, but isofukinone (7) has a double bond at C-1/C-10. The
cytotoxic peroxide 652 has been found only infrequently as a constituent of
Ligularia species.
Two reports on the constituents of L. thyrsoidea (Ledebour) de Candolle (samples
6 and 7) were reported, one from Bohlmann and Ziesche (1980) [131] and the other
by Jia’s group (1999) [233] (Sect. 3.13). Interestingly, they proved to be quite different from each other. The German sample 6 afforded furanoeremophilan-15-oic acid
195 as the major constituent, in addition to two 15-oxygenated furanoeremophilanes
(211 and 213), two germacratrienes (758 and 759), and two hydrocarbons (878 and
883). In turn, the Chinese sample 7 accumulated five bisabolane derivatives (709,
710, 711, 712, and 713) [233]. These results suggest that there is some chemical
diversity for this species, although additional samples are required to be examined.
3.39 Further Ligularia Species II: L. achyrotricha (Diels)
Y. Ling, L. nanchuanica S. W. Liu, L. purdomii (Turrill)
Chittenden, L. odontomanes Handel-Mazzetti, L. sibirica
(Linnaeus) Cassini, and L. thomsonii
(C. B. Clarke) Pojarkova
Ligularia achyrotricha (Diels) Y. Ling (sample 8 from Gansu Province, China) produced 11 aromatic compounds, which were, in turn, 925, 982, 983, 984, 989, 990,
991, 992, 1039, 1040, and 1042 (Table 47) [261].
Chemical Constituents of Ligularia Species (Asteraceae) and Their Diversity…