Triterpenoid saponins from the stem bark of Acanthopanax brachypus HARMS

Article abstract of DOI:10.1248/cpb.57.1000

Two new triterpenoid saponins, brachyposide A (1) {3-O- β-D-galactopyranosyl-(1→2)-[ β-D-xylopyranosyl-(1→3)]- β-D-glucuronopyranosyl-2 β,3 β,16 α,23-tetrahydroxyolean- 12-en-28-oic acid 28-O- β-D-apiofuranosyl-(1→ 3)- β-D- xylopyranosyl-(1→4)- α-L-rhamno

Full text of DOI:10.1248/cpb.57.1000

1
000
Notes
Chem. Pharm. Bull. 57(9) 1000—1003 (2009)
Vol. 57, No. 9
Triterpenoid Saponins from the Stem Bark of Acanthopanax brachypus
HARMS
Hao-Bin HU,* Xu-Dong ZHENG, Hong CAO, Xiao-Qiang GUO, and Huai-Sheng HU
College of Chemistry and Chemical Engineering, Longdong University; South Street 137, Xifeng District, Qingyang City,
7
45000, Gansu Province, China. Received March 19, 2009; accepted May 7, 2009; published online June 18, 2009
Two new triterpenoid saponins, brachyposide A (1) {3-O-b-D-galactopyranosyl-(1→2)-[b-D-xylopyranosyl-
1→3)]-b-D-glucuronopyranosyl-2b,3b,16a,23-tetrahydroxyolean-12-en-28-oic acid 28-O-b-D-apiofuranosyl-(1→
(
3
)-b-D-xylopyranosyl-(1→4)-a-L-rhamnopyranosyl-(1→2)-a-L-arabinopyranosyl ester} and brachyposide B (2)
{
1
3-O-b-D-glucopyranosyl-(1→3)-b-D-galactopyranosyl-(1→3)-b-D-glucuronopyranosyl-2b,3b,23-trihydroxyolean-
2-en-28-oic acid 28-O-b-D-xylopyranosyl-(1→4)-[b-D-apiofuranosyl-(1→3)]-a-L-rhamnopyranosyl-(1→2)-b-D-
glucopyranosyl ester}, together with four known triterpenoid saponins, including tabguticoside A, nipponoside
D, palmatoside E and ciwujianoside A , were isolated from the stem bark of Acanthopanax brachypus. Their
1
structures were elucidated on the basis of spectroscopic and chemical evidence.
Key words Acanthopanax brachypus; Araliaceae; triterpenoid saponin; brachyposide A; brachyposide B
1
0)
The Acanthopanax genus belonging to the Araliaceae fam- posides A and B (1 and 2), along with tabguticoside A (3),
11)
12)
ily includes 37 species around the world, which are widely nipponoside D (4), palmatoside E (5) and ciwujianoside
distributed in the northeast of Asia. Of these, 26 species and A (6) from the stem bark of A. brachypus. Among these
13)
1
1
8 varieties grow in mainland China, especially in the known compounds, compounds 3 and 5 were isolated for the
1,2)
north. The root and stem bark of these plants have been first time from this species.
clinically used for a long time as a tonic and sedative, as well
Compound 1 was obtained as a white amorphous powder,
as for the treatment of rheumatism, diabetes, chronic bron- and gave positive Liebermann-Burchard and Molish reac-
chitis, hypertension, anti-stress and ischemic heart disease, tions. The positive FAB-MS displayed a pseudo-molecular
3)
ꢀ
13
and gastric ulcer. Previous phytochemical studies on Acan- ion peak at m/z 1539 [MꢀNa] . Combined with C-NMR
thopanax species established the presence of triterpenoid data, its molecular formula was determined as C H108O37
saponins.
6
8
4—6)
ꢀ
by (HR)-FAB-MS, m/z 1517.6621 [MꢀH] (Calcd for
An endangered shrub in the wild due to overharvesting C H O , 1517.6647). The IR spectrum exhibited absorp-
6
8
109 37
ꢁ1
ꢁ1
and loss of habitat through deforestation, Acanthopanax tions at 3418 cm (OH), 1730 cm (ester carbonyl), and
brachypus HARMS is distributed in a narrow geographical 1648 cm (double bond). The spectral features and physico-
chemical properties revealed 1 to be a triterpenoid saponin.
Nowadays, the parts of this plant such as the roots, leaves The compound displayed 68 carbon signals in C-NMR
and flowers are employed for various therapeutic purposes in spectrum and various distortionless enhancement by polar-
ꢁ1
7)
area, most in the loess plateau of the northwest of China.
1
3
8)
China and Korea. However, to date, the research has mainly ization transfer (DEPT) data, of which 30 were assigned to
concentrated on the reproductive biology and ecology, and the aglycon and the remaining 45 to the sugar moieties
3
there have been few studies on the chemical composition and (Table 1). The six sp carbons at d 15.3, 16.8, 17.9, 23.8,
C
2
biological activity. Only syringaresinol diglucoside, syringin, 27.4 and 33.3, and the two sp carbons at d 123.0 (CH) and
C
1
sucrose, b-sitosterol and fatty acids have been previously iso- 144.4 (C), coupled with information from the H-NMR (six
9)
lated from this plant. Further phytochemical investigation angular methyl proton singlets at dH 0.93, 1.06, 1.18, 1.39,
led to the isolation of two new triterpenoid saponins: brachy- 1.58 and 1.76, and a broad triplet-like vinyl proton signal at
Fig. 1. Structures of Isolated Triterpenoid Glycosides 1—6
∗
To whom correspondence should be addressed. e-mail: hhb-88@126.com
© 2009 Pharmaceutical Society of Japan

September 2009
1001
d 5.58 (br s), indicated that the aglycon possessed an olean- apiose in the ratio of 1 : 1 : 2 : 1 : 1 : 1 as component sugars,
H
1
2-ene skeleton.
Furthermore, the hydroxymethyl (dH 3.72, 4.39 and d
which were identified by TLC and GC analysis after derivati-
zation. The H- and C-NMR spectra also showed seven
15)
1
13
C
6
5.8) and ester carbonyl (d 176.4) signals were assigned to anomeric proton signals at d 6.36 (d, Jꢂ2.8 Hz), 6.15 (br s),
C
H
C-23 and C-28 after an extensive 2D NMR study. Also, in 6.05 (d, Jꢂ4.8 Hz), 5.57 (d, Jꢂ7.6 Hz), 5.33 (d, Jꢂ7.5 Hz),
1
13
the H- and C-NMR spectra, three oxygenated methine car- 5.18 (d, Jꢂ7.8 Hz) and 4.81 (d, Jꢂ7.5 Hz), as well as one
bon signals (d 70.5, 83.7, 74.2) were observed, the corre- methyl doublet at d 1.75 (d, Jꢂ6.1 Hz), and the correspond-
sponding methine proton signals at d 4.81 (br s), 4.38 (d, ing carbon signals at d 93.8, 101.4, 111.6, 105.8, 106.2,
C
H
H
C
Jꢂ3.2 Hz) and 5.16 (br s), suggesting the methine protons 106.7, 105.5 and 18.5, respectively. The assignments of all
could be placed at 2a, 3a and 16b, respectively. Thus, the protons and carbon signals of the respective sugar compo-
aglycon was identified as 2b,3b,16a,23-tetrahydroxyolean- nents and the sequence of the oligosaccharide chain were de-
1
4)
1
1
1
2-en-28-oic acid (polygalacic acid). The chemical shifts termined by DEPT, H– H chemical shift correlation
1
1
1
of d 83.7 (C-3) and 176.4 (C-28) revealed that 1 was a 3,28- specroscopy ( H– H COSY), H-detected heteronuclear mul-
C
bisdesmoside. On acid hydrolysis, 1 afforded D-glucuronic tiple-bond correlation (HMBC) and nuclear Overhauser ef-
acid, D-galactose, D-xylose, L-arabinose, L-rhamnose and D- fect spectroscopy (NOESY) spectra of 1. The linkage of the
sugar units at C-3 of the aglycone was established from the
following HMBC correlations: H-1 (dH 5.57) of galactose
with C-2 (d 78.1) of glucuronic acid, H-1 (d 5.33) of xy-
C
H
lose with C-3 (d 85.7) of glucuronic acid, H-1 (d 4.81) of
C
H
glucuronic acid with C-3 (d 83.7) of the aglycone. Simi-
C
larly, the sugar chain at C-28 was established from the fol-
lowing HMBC correlations: H-1 (d 6.05) of apiose with C-
H
3
8
7
1
(d 84.5) of xylose, H-1 (d 5.18) of xylose with C-4 (d
C
H
C
C
C
3.1) of rhamnose, H-1 (d 6.15) of rhamnose with C-2 (d
H
5.9) of arabinose, H-1 (d 6.36) of arabinose with C-28 (d
H
76.4) of the aglycone. The same conclusion with regard to
the sugar sequence was also drawn from the NOESY experi-
ment. The D-galactose, D-xylose and D-glucuronic acid were
3
determined as b-configurations based on their J
values
H1–H2
(Jꢂ7.5—7.8 Hz), whereas the L-rhamnose was deduced as
a-configuration from the broad singlet of its anomeric proton
1
3
16)
and the C-NMR chemical shift values of C-3 and C-5.
1
Fig. 2. Selected HMBC and NOESY Correlations of 1
The a-anomeric configuration of the L-arabinose ( C config-
4
13
Table 1.
C-NMR (DEPT) Data of 1 and 2 in C D N (125 MHz)
5 5
No.
1
2
No.
1
2
No.
1
2
Aglycone
27
28
29
30
27.4, CH3
176.4, C
33.3, CH3
23.8, CH3
27.1, CH3
176.1, C
33.1, CH3
23.6, CH3
C-28-O-Sugar
Ara (Glc)
1
2
3
4
5
6
7
8
9
44.3, CH2
70.5, CH
83.7, CH
42.9, C
47.9, CH
18.2, CH2
33.4, CH2
40.2, C
47.8, CH
37.2, C
24.1, CH2
123.0, CH
144.4, C
42.6, C
36.3, CH2
74.2, CH
49.9, C
41.3, CH
47.1, CH2
30.8, C
36.2, CH2
32.4, CH2
65.8, CH2
15.3, CH3
17.9, CH3
16.8, CH3
44.5, CH2
70.7, CH
84.1, CH
42.6, C
47.8, CH
17.9, CH2
32.9, CH2
40.1, C
48.5, CH
37.0, C
23.9, CH2
123.1, CH
144.2, C
42.1, C
28.1, CH2
23.3, CH2
47.3, C
41.5, CH
46.9, CH2
30.9, C
35.7, CH2
32.6, CH2
65.4, CH2
15.1, CH3
17.6, CH3
16.7, CH3
Ara
Glc
1
2
3
4
5
6
Rha
1
2
3
4
5
6
Xyl
1
2
3
4
5
93.8, CH
75.9, CH
69.8, CH
65.8, CH
62.5, CH2
94.8, CH
78.3, CH
78.5, CH
71.2, CH
78.6, CH
62.4, CH2
C-3-O-Sugar
GlcA
1
2
3
4
5
6
Gal
1
2
3
4
5
6
105.5, CH
78.1, CH
85.7, CH
71.6, CH
77.1, CH
171.8, C
105.4, CH
74.5, CH
86.5, CH
71.4, CH
76.9, CH
172.1, C
101.4, CH
71.8, CH
72.3, CH
83.1, CH
68.5, CH
18.5, CH3
101.7, CH
71.7, CH
82.4, CH
78.7, CH
69.1, CH
18.7, CH3
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
105.8, CH
74.5, CH
75.4, CH
70.6, CH
76.5, CH
61.6, CH2
Xyl
106.2, CH
75.1, CH
78.6, CH
70.8, CH
67.2, CH2
105.6, CH
72.2, CH
81.3, CH
69.7, CH
76.8, CH
61.8, CH2
Glc
104.7, CH
75.4, CH
77.4, CH
70.1, CH
77.6, CH
61.4, CH2
106.7, CH
74.3, CH
84.5, CH
70.1, CH
67.8, CH2
105.8, CH
75.2, CH
78.4, CH
70.9, CH
67.4, CH2
Xyl (Glc)
1
2
3
4
5
6
Api
1
2
3
4
111.6, CH
77.5, CH
79.8, C
111.8, CH
77.6, CH
79.6, C
74.6, CH2
64.6, CH2
74.7, CH2
64.7, CH2
5

1
002
Vol. 57, No. 9
1
Table 2. Selected H-NMR Data of 1 and 2 in C D N (500 MHz, J in Hz)
Secondly, the presence of seven sugars in 2 was apparent
from the seven anomeric proton signals at dH 4.78 (d,
Jꢂ7.6 Hz), 5.51 (d, Jꢂ7.8 Hz), 5.41 (d, Jꢂ7.7 Hz), 6.22 (d,
Jꢂ7.5 Hz), 6.18 (br s), 5.28 (d, Jꢂ7.8 Hz) and 6.07 (d,
Jꢂ5.0 Hz), which correlated with the corresponding carbon
5
5
No.
1
2
No.
1
2
Aglycone
4
5
4.12
4.24
3.89
2
3
2
6
4.81, br s
4.79, br s
3.67, t, 10.1
4.27
4.38, d, 3.2
5.58, br s
5.16, br s
4.35, d, 3.2
5.52, br s
3.20
signals at d 105.4, 105.6, 104.7, 94.8, 101.7, 105.8 and
C
1
1
6
4.38
111.8, respectively. Acid hydrolysis of 2 gave D-glucuronic
4.49, dd, 12, 2
acid, D-glucose, D-galactose, D-xylose, L-rhamnose and D-
apiose in the ratio of 1 : 2 : 1 : 1 : 1 : 1 as component sugars,
which were identified by TLC and GC analysis after derivati-
2.86
C-28-O-Sugar
1
8
9
3.48,dd, 14.0, 3.5 3.34, dd, 14.0, 4.0
1.38, dd, 13.5, 3.8 1.82
Ara
Glc
1
1
2
3
4
5
6.36, d, 2.8
6.22, d, 7.5
4.26
15)
2
.76, t, 13.5
3.72, d, 11.0
.39, d, 11.0
1.12
4.65
3.92
4.28
4.22
4.41
zation. The assignments of all protons and carbon signals
of the respective sugar components and the sequence of the
2
3
3.71, d, 11.0
4.36, d, 11.0
1.39, s
4.29
4
4.27
1
1
oligosaccharide chain were also determined by DEPT, H– H
COSY, HMBC and NOESY spectra of 2. The b-anomeric
configurations of both D-glucoses were evident from the large
2
2
2
2
2
3
4
5
6
7
9
0
1.39, s
1.58, s
1.18, s
1.76, s
0.93, s
1.06, s
3.96
1.57, s
1.17, s
6
4.32
3
1.28, s
4.38, dd, 12, 2
JH1–H2 (Jꢂ7.5, 7.7 Hz). The anomeric configurations of the
0.93, s
Rha
1
other sugar units were identical to the corresponding ones
in compound 1. Thus, the structure of 2 was determined to
be 3-O-b-D-glucopyranosyl-(1→3)-b-D-galactopyranosyl-
(1→3)-b-D-glucuronopyranosyl-2b,3b,23-trihydroxyolean-
1.05, s
6.15, br s
4.85
6.18, br s
4.92
C-3-O-Sugar
2
GlcA
3
4.12
4.45
1
2
4.81, d, 7.5
4.78, d, 7.6
3.88
4
4.23
4.29
4.35
4.28
4.45
4.52
5
4.38
4.35
1
2-en-28-oic acid 28-O-b-D-xylopyranosyl-(1→4)-[b-D-api-
3
4.25
6
1.75, d, 6.1
1.78, d, 6.0
ofuranosyl-(1→3)]-a-L-rhamnopyranosyl-(1→2)-b-D-glu-
copyranosyl ester, and termed brachyposide B (Fig. 1).
4
4.42
Xyl
1
5
4.50
5.18, d, 7.8
3.98
5.28, d, 7.8
4.03
Gal
1
2
Experimental
5.57, d, 7.6
4.46
5.51, d, 7.8
4.48
3
4.09
3.91
General Procedures Melting points were determined on X-4 digital
micro-melting point apparatus and were uncorrected. Optical rotations were
measured with a Perkin-Elmer 341 digital polarimeter. IR spectra were
recorded with KBr pellets on a Perkin-Elmer 577 spectrometer. GC analysis
was performed with a Hewlett Packard 6890 Series gas chromatograph
2
4
4.18
4.16
3
4.12
4.21
5
3.52
3.50
4
4.56, d, 3.1
4.01
4.50, d, 3.0
4.02
4.21, d, 7.8
4.22, t, 7.8
5
Api
1
6
4.30
4.28
6.05, d, 4.8
4.76, d, 4.5
6.07, d, 5.0
4.77, d, 4.5
equipped with an H flame ionization detector. The FAB-MS were recorded
2
4
.52
4.51
2
on a VG Autospec 3000 mass spectrometer, and the NMR spectra were
Xyl
Glc
4
4.03, d, 11.0 4.02, d, 11.0
4.05, d, 11.0 4.05, d, 11.0
1
recorded with a Bruker AMX-500 (500 MHz for H-NMR and 125 MHz for
1
2
3
5.33, d, 7.5
3.94
5.41, d, 7.7
4.02
1
3
C-NMR). Chemical shifts were given in d (ppm) with tetramethyl silane
TMS) as an internal standard and coupling constants (J) were reported in
5
4.26, d, 9.5
4.65, d, 9.5
4.19, d, 9.5
4.57, d, 9.5
(
4.11
4.17
Hertz (Hz). Column chromatography was performed with Silica-gel H
Qingdao Haiyang Chemical Plant, P. R. China), Diaion HP-20 (Mitsubishi
(
GlcAꢂb-D-glucuronopyranosyl, Glcꢂb-D-glucopyranosyl, Araꢂa-L-arabinopyra-
nosyl, Galꢂb-D-galactopyranosyl, Apiꢂb-D-apifuranosyl, Rhaꢂa-L-rhamnopyranosyl,
Xylꢂb-D-xylopyranosyl.
Chemical, Japan), Sephadex LH-20 (Pharmacia), and macroporous resin
D101 (26—60 mesh, Tianjin Haiguang Chemical Company, P. R. China).
Thin-layer chromatography (TLC) employed precoated Silica-gel GF254
plates (Qingdao Haiyang Chemical Plant, China) and detection was
3
achieved by 10% H
for sugars.
Plant Material The stem bark of A. brachypus was collected in August
2 4
SO –EtOH for saponins, and aniline-phthalate reagents
uration) was determined by its J
(
(2.8 Hz) and JC1–H1
H1–H2
17)
172 Hz) value. The b-anomeric configuration of the D-
13
apiose was determined by the comparison of the C-NMR of 2007 from Qingyang of Gansu Province, P. R. China, and identified by
data for 1 with those for a and b-D-apiofuranosides, and the Prof. Xiao-qiang Guo, Department of Life-Sciences, Longdong University,
3
P. R. China. A voucher specimen (10732) was deposited in the Herbarium of
the Department of Life-Sciences, Longdong University.
J
value of the apiose was similar to the reported data of
Based on the above evidence, the
structure of 1 was determined to be 3-O-b-D-galactopyra-
H1–H2
18)
b-D-apiofuranoside.
Extraction and Isolation The air-dried and pulverized stem bark of A.
brachypus (30.0 kg) was extracted three times with 75% aqueous EtOH
nosyl-(1→2)-[b-D-xylopyranosyl-(1→3)]-b-D-glucuronopy- (15 lꢃ7 d, each time) at room temperature, and then the extracts were com-
bined and concentrated under reduced pressure at 60 °C to give 1460 g of
ranosyl-2b,3b,16a,23-tetrahydroxyolean-12-en-28-oic acid
brown viscous residue. The residue was disolved in MeOH (1.5 l) and pre-
cipitated in acetone (3 l). The dry precipitate was suspended in H O, and fur-
2
8-O-b-D-apiofuranosyl-(1→3)-b-D-xylopyranosyl-(1→4)-
2
a-L-rhamnopyranosyl-(1→2)-a-L-arabinopyranosyl
ester,
ther extracted with n-BuOH to retain the saponins which have less than nine
20)
and called brachyposide A (Fig. 1).
sugar units. The n-BuOH-soluble fraction (156 g) was subjected to column
Compound 2 was obtained as a white amorphous powder chromatography by a combination of D101 macroporous resin, eluted gradi-
ently with H O, EtOH (10→95%) to give five fractions (Fr. A—E). Fraction
with the molecular formula C H O , as determined from
2
7
0
112 38
A (22.3 g) was subjected to a silica gel column with a CHCl –MeOH gradi-
3
the data of the positive (HR)-FAB-MS (m/z 1561.6873
ent system (1 : 0→0 : 1), affording 8 subfractions. Subfractions 3 (1.1 g) and
7 (1.1 g) were respectively purified by repeated octadecyl silane (ODS) col-
ꢀ
13
[
MꢀH] , Calcd for C H O , 1561.6910), C-NMR (70
70 113 38
carbon signals), and various DEPT spectra. The NMR and umn chromatography (MeOH–H O) to afford compounds 4 (39.4 mg) and 3
2
DEPT spectra of the aglycone 2 were almost similar to those (16.4 mg). Fraction C (17.5 g) was separated on Sephadex LH-20 column
with MeOH, and further recrystallized with MeOH to provide compounds 5
of 1, apart from the change of the oxymethine (d 5.16 and
H
(18.1 mg) and 6 (22.4 mg). Fraction E (14.7 g) was separated on Sephadex
d 74.2) in 1 to methene (d 2.86, 3.20 and d 23.3) in 2,
C
H
C
LH-20 column with MeOH, and further purified on ODS column with
suggesting the hydroxyl group at C-16 in 1 was absent in
the aglycone 2. Thus, the aglycone of 2 was identified as
MeOH–H O to provide compounds 1 (10.8 mg) and 2 (13.2 mg).
2
2
0
Brachyposide A (1): White amorphous powder. [a] ꢁ36.5° (cꢂ0.22,
MeOH). IR (KBr) nmax cm : 3418, 2937, 1730, 1648, 1422, 1074. H-NMR
D
19)
ꢁ1
1
2b,3b,23-trihydroxyolean-12-en-28-oic acid (bayogenin).

September 2009
pyridine-d , 500 MHz) and C-NMR (pyridine-d , 125 MHz): see Tables 1 References
1003
1
3
(
5
5
ꢀ
and 2. (HR)-FAB-MS (positive) m/z: 1517.6621 [MꢀH] (Calcd for
1) Delectis Florae Reipublicae Popularis Sinicae, Agendae Academiae
Sinicae Edita, “Florae Reipublicae Popularis Sinicae,” Vol. 54, Science
Press, Beijing, 1980, pp. 104—106.
2) Ni N., Liu X. Q., Chin. Tradit. Herb. Drugs, 37, 1895—1900 (2006).
3) Nishibe S., Kinoshita H., Takeda H., Okano G., Chem. Pharm. Bull.,
38, 1763—1765 (1990).
C H O , 1517.6647).
Brachyposide B (2): White amorphous powder. [a] ꢁ18.6° (cꢂ0.18,
MeOH). IR (KBr) n cm : 3422, 2938, 1727, 1652, 1423, 1072. H-NMR
68
109 37
2
0
D
ꢁ1
1
max
1
3
(
pyridine-d , 500 MHz) and C-NMR (pyridine-d , 125 MHz): see Tables 1
5 5
ꢀ
and 2. (HR)-FAB-MS (positive) m/z: 1561.6873 [MꢀH] (Calcd for
C H O , 1561.6910).
Acid Hydrolysis of Compounds 1 and 2 and Determination of the Ab-
4) Chang S. Y., Yook C. S., Nohara T., Chem. Pharm. Bull., 46, 163—
165 (1998).
70
113 38
solute Configuration of the Monosaccharide A solution of compounds 1
or 2 (5.0 mg) in 2 mol/l HCl–dioxane (1 : 1, 1 ml) was refluxed in a water
bath at 90 °C for 2 h. After dioxane was removed, the solution was extracted
with EtOAc (1 mlꢃ3). The aqueous layer was neutralized by passing
5) Yook C. S., Kim I. H., Hahn D. R., Nohara T., Chang S. Y., Phyto-
chemistry, 49, 839—843 (1998).
6) Chang S. Y., Yook C. S., Nohara T., Phytochemistry, 50, 1369—1374
(1999).
through an Amberlite MB-3 resin column eluted with H O, then concen-
7) Wang Z. L., Liu L. D., Tian G. W., Shen J. H., Biodiv. Sci., 5, 251—
256 (1997).
8) Yi J. M., Kim M. S., Seo S. W., Lee K. N., Yook C. S., Kim H. M.,
Clin. Chim. Acta, 32, 163—168 (2001).
9) Wei P., Yu G. M., Chin. Tradit. Herb. Drugs, 20, 152—154 (1989).
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Chem. Lett., 10, 391—394 (1999).
2
trated and dried to furnish a monosaccharide residue. Then, the sugars were
detected by TLC analysis [CHCl –CH OH–H O–HOAc (15 : 6 : 2 : 3), detec-
3
3
2
tion solution: aniline-phthalic acid] against the standard samples. The
residue was dissolved in pyridine (0.2 ml), and then a pyridine solution
(0.3 ml) of L-cysteine methyl ester hydrochloride (5 mg) was added to the
solution. The mixture was kept at 60 °C for 1.5 h, dried in vacuo, and
trimethylsilylated with hexamethyl-disilazane-trimethylchlorosilane (HMDS- 11) Miyakoshi M., Shirasuna K., Hirai Y., Shingu K., Isoda S., Shoji J.,
TMCS) (0.1 ml) at 60 °C for 1 h. After being partitioned between n-hexane
Ida Y., Shimizu T., J. Nat. Prod., 62, 445—448 (1999).
0.5 ml) and H O (0.5 ml), the n-hexane extract was concentrated and ana- 12) Tommasi N. D., Autore G., Bellino A., Pinto A., Pizza C., Sorrentino
(
2
lyzed by GC under the following conditions: HP-5 MS fused silica capillary
column (30 mꢃ0.25 mm, film thickness 0.25 mm), column temperature at
2
confirmed by comparison of the retention times of their derivatives with 14) Asada Y., Ueoka T., Furuyua T., Chem. Pharm. Bull., 37, 2139—2146
standard samples [retention time, D-glucuronic acid (20.1 min), D-glucose
R., Venturella P., J. Nat. Prod., 63, 308—314 (2000).
13) Shao C. J., Kasai R., Xu J. D., Tanaka O., Chem. Pharm. Bull., 37,
42—45 (1989).
30 °C, injection temperature at 250 °C, N as carrier gas. The sugars were
2
(1989).
(
(
24.7 min), D-galactose (26.6 min), D-xylose (17.5 min), L-rhamnose
19.3 min), L-arabinose (18.8 min) and D-apiose (12.8 min)]. The presence of
15) Zhao J., Nakamura N., Hattori M., Yang X. W., Komatsu K., Qiu M.
H., Chem. Pharm. Bull., 52, 230—237 (2004).
D-glucuronic acid, D-galactose, D-xylose, L-arabinose, L-rhamnose and D-
apiose in 1, D-glucuronic acid, D-galactose, D-xylose, D-glucose, L-rhamnose
and D-apiose in 2 were detected.
16) Sang S., Lao A., Wang H., Chen, Z., J. Nat. Prod., 62, 1028—1029
(1999).
17) Ishii H., Kitagawa I., Matsushita K., Shirakawa K., Tori K., Tozyo T.,
Yoshikawa M., Yoshimura Y., Tetrahedron Lett., 22, 1529—1532
(1981).
Acknowledgements This work was financially supported by the Sup-
port Program for Longyuan Scientific and Technical Innovation Talented 18) Su Y. F., Koike K., Guo D., Satou T., Liu J. S., Zheng J. H., Nikaido T.,
Person of Gansu Province and the Scientific Research Project of Longdong
University (XYZK0802) of China.
Tetrahedron, 57, 6721—6726 (2001).
19) Abdulmagid A. M., Laurence V. N., Isabelle R., Dominique H., Christ-
ian M., Catherine L., Phytochemistry, 67, 2096—2102 (2006).
2
0) Wang M. K., Wu F. E., Chen Y. Z., Phytochemistry, 44, 333—335
1997).
(