Eudesmane-type sesquiterpene derivatives from Saussurea conica

Article abstract of DOI:10.1002/hlca.200490131

Four new eudesmane-type sesquiterpene derivatives, 3β-[(β-D- glucopyranosyl)oxy]-11αH-eudesm-4(14)-en-12,8β-olide (1), (3β)-eudesma-4(14),11(13)-diene-3,12-diol (2), 3β-[(β-D- glucopyranosyl)oxy]eudesma-4(14),11(13)-dien-12-ol (3), and 3β-[(β-D- glucopyra

Full text of DOI:10.1002/hlca.200490131

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Helvetica Chimica Acta Vol. 87 (2004)
Eudesmane-Type Sesquiterpene Derivatives from Saussurea conica
by Cheng-Qi Fana), Zha-Jun Zhana), Hui Lib), and Jian-Min Yue*a)
a) State Key Laboratory of Drug Research, Institute of Materia Medica, Shanghai Institutes for Biological
Sciences, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park, Shanghai, 201203,
P. R. China
(Phone: ‡86-21-50806718; fax: ‡86-21-50806718; e-mail: jmyue@mail.shcnc.ac.cn)
b) Tibet Plateau Institute of Biology, 93 Beijing Zhonglu Road, Lasa 850001, P. R. China
Four new eudesmane-type sesquiterpene derivatives, 3b-[(b-d-glucopyranosyl)oxy]-11aH-eudesm-4(14)-
en-12,8b-olide (1), (3b)-eudesma-4(14),11(13)-diene-3,12-diol (2), 3b-[(b-d-glucopyranosyl)oxy]eudesma-
4(14),11(13)-dien-12-ol (3), and 3b-[(b-d-glucopyranosyl)oxy]eudesm-4(14)-en-11-ol (4), together with the
known (3b)-eudesm-4(14)-ene-3,11-diol (5) were isolated from Saussurea conica, and their structures were
elucidated both spectroscopically and by chemical methods.
Introduction. The whole plants of the Saussurea genus (Asteraceae), precious
herb medicines in both traditional Chinese and Tibet folklore medicine, are being used
to cure rheumatic arthritis, dysmenorrhea and gynopathy [1]. A variety of sesquiter-
pene derivatives from this genus have been reported to possess interesting biological
activities [2]. The plant Saussurea conica C. B. Clarke has not been investigated
chemically so far. In preliminary investigations, we found that S. conica contains several
sesquiterpene derivatives. Herein, we present the isolation and structural identification
of four new and one known eudesmane-type sesquiterpene derivatives, i.e., 1 4 and 5,
respectively.
Results and Discussion. Compound 1 was obtained as a white amorphous powder.
Its molecular formula (C21H32O8) was deduced by positive- and negative-mode ESI-MS
‡
(m/z 435.2 ([M ‡ Na] ) and 411.4 ([M À H]À), respectively) in combination with

Helvetica Chimica Acta Vol. 87 (2004)
1447
13C-NMR (DEPT) spectral data. The signals of a b-d-glucopyranosyl (Glc) moiety
1
were observed in the H- and 13C-NMR spectra of 1 (see Tables 1 and 2, resp.). The
remaining 15 C-atoms of the aglycone were identified as a singlet Me, a doublet Me, five
CH2 (one olefinic), and five CH (two oxygenated) groups, as well as three quaternary
C-atoms (including one olefinic and one CˆO group). The quaternary C-atom at d(C)
149.06 and the signal for an olefinic secondary C-atom at d(C) 105.70 indicated the
presence of an exocyclic CˆC bond. The aforementioned spectral data suggested that
compound 1 was a glucoside of a tricyclic sesquiterpene. The aglycone moiety was
further identified as a sesquiterpene lactone of the eudesmane type (see chemical
1
formulae) by extensive analysis of 13C-NMR (DEPT) and H-NMR spectral data.
Thus, compound 1 was identified as 3b-[(b-d-glucopyranosyl)oxy]-11aH-eudesm-
4(14)-en-12,8b-olide.
In the HMBC spectrum of 1, the signal at d(H) 2.83 (HÀC(11)) correlated with both d(C) 9.59 (d, Me(13))
and d(C) 179.28 (s, C(12)ˆO). The signal at d(H) 4.50 (dd, J ˆ 4.7, 11.4 Hz, HÀC(3)) correlated with the
anomeric C-atom of the Glc moiety at d(C) 103.26 (C(1')), as well as with the olefinic signals at d(C) 105.70
(CH2(14)) and 149.06 (C(4)) in the HMBC spectrum, indicating the presence of a 3-O-Glc moiety and D4(14)
unsaturation. The signal at d(H) 0.79 (s, Me(15)) correlated with d(C) 34.87 (s, C(10)). The resonance at d(H)
4.38 (br. s, HÀC(8)) showed a cross-peak with the CˆO signal, indicating that the lactone group was between
C(8) and C(12), as in many sesquiterpenes of the eudesmane type. The final assignment of all atoms was based
1
on a combination of H- and 13C-NMR (Tables 1 and 2, resp.), HMQC, HMBC, and NOESY spectra. From the
NOESY experiment (Figure), the relative configuration of 1 could also be determined.
Fig. 1. Key NOESY correlations for the eudesmenolide 1
The molecular formula of 2 was found to be C15H24O2, as deduced by HR-EI-MS
‡
(m/z 236.1774 (M ; calc. 236.1776)). The 1H- and 13C-NMR spectral data (Tables 1 and
2) inferred that compound 2 was a sesquiterpene. Fifteen C-atom signals were
observed: one Me, eight CH2 (two olefinic and one oxygenated), three CH (one
oxygenated) groups, and three quaternary C-atoms (two olefinic), thus, indicating the
presence of two terminal (exocyclic) CˆC bonds. The mass-spectrum fragments and
NMR data of 2 were very similar to 3a-hydroxycostol [3] (see Table 1), except for the
coupling constants for HÀC(3) at d(H) 4.02 (dd, J ˆ 5.6, 11.4 Hz) in 2 (the coupling
constant of HÀC(3) of 3a-hydroxycostol was only 2.8 Hz), indicating the presence of a
3b-OH group in 2. The slightly altered chemical shifts for HÀC(3), HÀC(5), and
CH2(14) in 2 relative to those of 3a-hydroxycostol (Table 1) could be rationalized by a
different configuration at C(3). Thus, compound 2 was identified as (3b)-eudesma-
4(14),11(13)-diene-3,12-diol.
Compound 3 showed a molecular formula of C21H34O7, as deduced by positive- and
‡
negative-mode ESI-MS (m/z 421.2 ([M ‡ Na] ) and 397.3 ([M À H]À)) in combination
with 13C-NMR (DEPT) experiments. The presence of a b-d-glucopyranosyl moiety was

1
Table 1. 400-MHz H-NMR Data ofthe New Compounds 1 4 and ofthe Reference Substance 3 a-Hydroxycostol [3]. Solvents: (D5)pyridine (1), CDCl3 (2 and 3a-
hydroxycostol), CD3OD (3 and 4). d in ppm, J in Hz. Asterisks mark overlapping signals.
H-Atom
1
2
3
4
3a-Hydroxycostola)
CH2(1)
1.05 (dt, J ˆ 2.8, 10.8)
1.70, 2.05 (m)
4.50 (dd, J ˆ 4.7, 11.4)
1.53 (br. d, J ˆ 12.2)
1.45 (dd, J ˆ 5.4, 13.4), 1.21*
2.25 (m)
1.37, 1.50 (m)
1.51, 1.99 (m)
4.02 (dd, J ˆ 5.6, 11.4)
1.77 (br. d, J ˆ 12.7)
1.39, 1.62 (m)
1.38, 1.48 (m)
1.61, 1.97 (m)
4.20 (dd, J ˆ 5.4, 11.6)
1.77 (br. d, J ˆ 10.8)
1.42, 1.58 (m)
2.03 (m)
1.37, 1.47 (m)
1.60, 1.97 (m)
4.19 (dd, J ˆ 5.4, 11.5)
1.69 (br. d, J ˆ 11.1)
1.25, 1.63 (m)
1.35 (m)
CH2(2)
HÀC(3)
HaÀC(5)
CH2(6)
4.23 (t, J ˆ 2.8)
2.30 (br. d, J ˆ 12.5)
HaÀC(7)
2.04 (m)
1.46, 1.63 (m)
b
CH2(8)
CH2(9)
)
4.38 (br. s)
2.02 (br. d, J ˆ 15.5), 1.21*
1.45, 1.63 (m)
1.25, 1.60 (m)
1.32, 1.63 (m)
1.21, 1.55 (m)
1.24 (dt, J ˆ 4.2, 13.8),
1.58 (m)
HaÀC(11)
2.83 (m)
c
CH2(12)
CH2(13)
CH2(14)
Me(15)
)
4.12 (s)
4.06 (s)
1.16 (s)
1.16 (s)
4.63, 5.39 (br. s)
0.71 (s)
4.08 (s)
c
)
1.18 (d, J ˆ 7.1)
4.78, 6.13 (br. s)
0.79 (s)
4.94, 5.06 (br. s)
4.62, 5.05 (br. s)
0.73 (s)
4.91, 5.03 (br. s)
4.60, 5.39 (br. s)
0.74 (s)
4.87, 4.99 (s)
4.51, 4.87 (s)
0.66 (s)
HÀC(1')
HÀC(2')
HÀC(3')
HÀC(4')
HÀC(5')
CH2(6')
5.08 (d, J ˆ 7.9)
4.12 (t-like, J ˆ 7.3)
4.25 (m)
4.37 (d, J ˆ 7.8)
4.38 (d, J ˆ 7.7)
3.23 (m)
3.25 (m)
3.33 (m)
3.28 (m)
3.23 (m)
3.25 (m)
3.27 (m)
3.23 (m)
4.23 (m)
4.00 (t-like, J ˆ 7.0)
4.62 (br. d, J ˆ 11.5),
4.40 (dd, J ˆ 5.7, 11.5)
3.88 (dd, J ˆ 2.2, 11.9),
3.86 (dd, J ˆ 2.1, 11.9),
3.68 (dd, J ˆ 5.8, 11.9)
3.64 (dd, J ˆ 5.7, 11.9)
a) Diagnostic signals from [3]. b) HaÀC(8) in the case of 1. c) Me groups in the case of 4.

Helvetica Chimica Acta Vol. 87 (2004)
1449
inferred from the 1H- and 13C-NMR spectral data (Tables 1 and 2, resp.). Except for the
sugar moiety, the NMR spectral data of the aglycone of 3 were very similar to those of
2. Acid hydrolysis of 3 afforded d-glucose (Glc) and an aglycone, the latter being
identical with that of 2 according to TLC, optical rotation, 1H-NMR, and EI-MS. In the
HMBC spectrum of 3, an oxygenated CH group at d(C) 80.39 (C(3)) showed
correlations with the CH2(14) resonances at d(H) 4.60 (br. s) and 5.39 (br. s), and with
the anomeric H-atom of the Glc moiety at d(H) 4.37 (d, J ˆ 7.8 Hz, HÀC(1')),
indicating that the glucopyranosyloxy moiety was at C(3). From these results and 2D-
NMR experiments (HMQC and HMBC), the structure of 3 was elucidated as 3b-[(b-
d-glucopyranosyl)oxy]eudesma-4(14),11(13)-dien-12-ol.
Table 2. 100-MHz 13C-NMR Data ofCompounds 1 5. Solvents: (D5)pyridine (1), CDCl3 (2 and 5), CD3OD (3
and 4). d in ppm, J in Hz.
Position
1
2
3
4
5
1
2
3
40.38
31.32
78.54
39.64
32.52
73.11
41.34
32.73
80.39
41.32
32.77
80.43
39.67
32.82
73.32
4
5
6
7
8
9
10
11
12
13
14
15
1'
2'
3'
4'
5'
6'
149.06
45.16
21.86
40.31
77.83
41.47
34.87
41.92
179.28
9.59
105.70
18.07
103.26
75.74
78.82
72.02
78.82
63.10
152.53
48.01
29.78
41.01
27.07
40.61
35.58
153.62
64.86
107.79
102.36
16.28
150.90
49.93
31.59
42.86
28.83
42.31
37.09
155.63
65.60
108.51
105.01
17.12
103.35
75.82
78.50
72.11
78.23
63.15
151.17
49.82
26.62
50.84
23.86
42.33
37.01
73.62
27.18
27.60
104.92
17.11
103.33
75.83
78.50
72.12
78.23
63.15
153.04
47.99
25.01
49.18
22.31
40.67
35.58
72.85
27.02
27.29
102.23
16.31
Compound 4 was also found to be a sesquiterpene glycoside, as judged from its
spectral data. A molecular formula of C21H36O7 was deduced by positive- and negative-
‡
mode ESI-MS (m/z 423.1 ([M ‡ Na] ) and 399.4 ([M À H]À)) in combination with
13C-NMR (DEPT) experiments. Acid hydrolysis of 4 yielded d-glucose (Glc) and an
aglycone identical to (3b)-eudesm-4(14)-ene-3,11-diol (5), isolated previously from
this plant [4]. Comparison of 13C-NMR spectral data (Table 2) revealed that C(3) at
d(C) 80.43 of 4 was shifted downfield by ca. 7.1 ppm relative to 5 due to glucosylation,
indicating that the sugar moiety was at C(3). This was corroborated by HMBC
correlations between C(3) and CH2(14) (d(H) 4.63, 5.39 (2d, J ˆ 1.1 Hz)), as well as
between C(3) and C(1') of the Glc moiety at d(H) 4.38 (d, J ˆ 7.7 Hz). The Glc moiety
was assigned the b-configuration according to the large coupling constant (J ˆ 7.7 Hz )
of the anomeric H-atom. Compound 4 was, thus, identified as 3b-[(b-d-glucopyrano-
syl)oxy]eudesm-4(14)-en-11-ol.

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Helvetica Chimica Acta Vol. 87 (2004)
Experimental Part
General. Solvents were of anal. grade (Shanghai Chemical Plant). Thin-layer chromatography (TLC):
precoated silica-gel-GF254 plates (Qingdao Haiyang Chemical Plant). Column chromatography (CC): Silica gel
(200 300 mesh) or MCI GEL CHP20P (75 150 mm; Mitsubishi Chemical Industries); reverse-phase (RP) CC:
C18 silica gel (150 200 mesh; Merck). Optical rotation: Perkin-Elmer 341 polarimeter. IR Spectra: Perkin-
Elmer 577 spectrometer; in cmÀ1. NMR Spectra: Bruker AM-400 and Varian Mercury-400 spectrometers; at 400
(1H) and 100 (13C) MHz; d in ppm rel to SiMe4 (ˆ0 ppm), J in Hz. EI-MS (70 eV): Finnigan MAT-95 mass
spectrometer, in m/z (rel. %).
Plant Material. The whole plant of Saussurea conica was collected in September 2000 in the Tibet
Autonomous Region of China, and was identified by H. L. A voucher specimen (Access No. Sc-2000-2Y) was
deposited at the Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese
Academy of Sciences, P. R. China.
Extraction and Isolation. Dried and powdered Saussurea conica (whole plant; 1.5 kg) was extracted with
95% aq. EtOH at r.t. to give, after evaporation, a crude extract (128 g). The residue was suspended in H2O
(1500 ml) and extracted with CHCl3 and BuOH to afford water-soluble (W; 46 g), CHCl3-soluble (CL; 47 g),
and BuOH-soluble (BU; 32 g) fractions, respectively. The BuOH extract (30 g) was subjected to CC (MCI
CHP20P; H2O (1500 ml)1), then MeOH/H2O 20 :80, 40 :60, 60 :40, and 100 :0 (1000 ml each)) to give fraction
BU-4 (1.57 g), which contained mainly sesquiterpene glycosides (TLC). BU-4 was subjected to CC (SiO2;
CHCl3/MeOH 8 :1, 6 :1, and 4 :1 (800 ml each)): fractions BU-4a e. Compound 1 (9 mg) was obtained from
BU-4b by CC (Sephadex LH-20; EtOH/H2O 70 :30). BU-4c was further purified by CC (Sephadex LH-20;
EtOH/H2O 70 :30) and RP-CC (C18 SiO2; column: 1.5 Â 30 cm; MeOH/H2O 55 :45 ! 60 :40 (180 ml each)) to
give compounds 3 (14 mg) and 4 (17 mg). The CL fraction (45 g) was subjected to CC (SiO2; CHCl3/MeOH 1:0,
20 :1, 15 :1, 9 :1, 6 :1, and 4 :1 (4500 ml each)): fractions CL-1 7. CL-5 (3.03 g) was subjected to CC (SiO2;
petroleum ether/acetone 4 :1, 3 :1, and 2 :1 (1200 ml each)) to afford fractions CL-5c and CL-5d, among other
mixtures. From CL-5c, 5 (120 mg) was isolated by RP-CC (C18 SiO2; MeOH/H2O 70 :30 (250 ml each)). CL-5d
was purified by CC (Sephadex LH-20, EtOH) to yield 2 (85 mg).
3b-[(b-d-Glucopyranosyl)oxy]-11aH-eudesm-4(14)-en-12,8b-olide (1). White amorphous powder. [a]D20
ˆ
À61.2 (c ˆ 1.10, pyridine). IR (KBr): 3507, 3423, 3302, 2946, 2861, 1747, 1647, 1454, 1355, 1180, 1125, 1077, 1022,
‡
964, 939. 1H- and 13C-NMR: see Tables 1 and 2, resp. ESI-MS (pos.): 847.3 (82, [2M ‡ Na] ), 435.2 (100, [M ‡
‡
Na] ); ESI-MS (neg.): 823.7 (100, [2M À H]À), 411.4 (53, [M À H]À).
(3b)-Eudesma-4(14),11(13)-diene-3,12-diol (2). White amorphous powder. [a]2D0 ˆ ‡34.5 (c ˆ 0.290,
MeOH). IR (KBr): 3280, 2919, 2848, 1650, 1637, 1446, 1433, 1047, 1022, 899, 891. 1H- and 13C-NMR: see
‡
Tables 1 and 2, resp. EI-MS: 236 (24, M ), 218 (25), 203 (22), 133 (81), 107 (81), 105 (93), 101 (100), 91 (98), 79
‡
‡
(85). HR-EI-MS: 236.1774 (M , C15H24O2 ; calc. 236.1776).
3b-[(b-d-Glucopyranosyl)oxy]eudesma-4(14),11(13)-dien-12-ol (3). Colorless gum. [a]2D0 ˆ À31.9 (c ˆ
0.500, MeOH). IR (KBr): 3405, 2927, 1650, 1450, 1379, 1161, 1079, 1028, 899. H- and 13C-NMR: see Tables 1
1
‡
‡
and 2, resp. ESI-MS (pos.): 819.3 (97, [2M ‡ Na] ), 421.2 (100, [M ‡ Na] ). ESI-MS (neg.): 795.5 ([90, [2M À
H]À), 397.3 (100, [M À H]À).
3b-[(b-d-Glucopyranosyl)oxy]eudesm-4(14)-en-11-ol (4). Colorless gum. [a]2D0 ˆ À17.6 (c ˆ 0.560,
MeOH). IR (KBr): 3394, 2937, 1631, 1452, 1379, 1159, 1079, 1024, 910. H- and 13C-NMR: see Tables 1 and 2,
1
resp. ESI-MS (pos.): 823.5 (100, [2M ‡ Na] ), 423.1 (61, [M ‡ Na] ). ESI-MS (neg.): 799.3 (53, [2M À H]À),
‡
‡
399.4 (100, [M À H]À).
Acid Hydrolyses ofCompounds 3 and 4. Compound 4 (5 mg) was dissolved in 4 ml of a 3% aq. H2SO4/
MeOH 1:1 soln., which was refluxed for 3 h. Then, the mixture was neutralized with 5% aq. NaHCO3 soln.
After workup, the crude product was purified by CC (Sephadex LH-20; EtOH) to give d-glucose (Glc), as
identified by TLC and optical rotation, together with 5 (1.8 mg) as the aglycone. Compound 3 (4 mg) was
subjected to the same procedure, affording Glc and 2 (1.1 mg).
Financial support of the Natural Science Foundation ofthe People×s Republic ofChina (No. 30371678) is
gratefully acknowledged.
1
)
To remove small polar molecules such as sugars and amino acids.

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Pharm. Bull. 1993, 41, 214.
[3] A. G. Gonzalez, J. B. Barrera, J. T. Mendez, M. J. Sanchez, J. L. E. Martinez, Phytochemistry 1992, 31, 1816.
[4] J. de Pascual-Teresa, I. S. Bellido, M. S. Gonzalez, Tetrahedron 1980, 36, 371.
Received January 20, 2004