Chemical constituents from the leaves and stems of Schisandra lancifolia

Article abstract of DOI:10.1248/cpb.58.852

A new nortriterpenoid, 20-hydroxymicrandilactone D (1) and a novel lignan glycoside, lancilignanside A (2) were isolated from leaves and stems of Schisandra lancifolia, together with three known nortriterpenoids (3-5) and nine known phenolics (6-14). The structures of new compounds 1 and 2 were determined by detailed analysis of their 1D and 2D NMR spectra, and chemical evidences. In addition, compounds 1-2, 6-7, and 9-11 showed anti-human immunodeficiency virus (HIV)-1 activities with 50% effective concentration (EC₅₀) in the range of 3.0-99.0 μg/ml. Compound 12 was not bioactive in this assay with EC₅₀ more than 200 μg/ml.

Full text of DOI:10.1248/cpb.58.852

852
Note
Chem. Pharm. Bull. 58(6) 852—855 (2010)
Vol. 58, No. 6
Chemical Constituents from the Leaves and Stems of Schisandra lancifolia
Wei-Lie XIAO,a Liu-Meng YANG,b Hai-Bo ZHANG,a,c Yong-Bo XUE,a,c Guang-Yu YANG,a,d
a
b
b
,a
*
Jian-Xin PU, Rui-Rui WANG, Yong-Tang ZHENG, and Han-Dong SUN
a State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese
Academy of Sciences; Kunming 650204, Yunnan, P. R. China: b Key Laboratory of Animal Models and Human Disease
Mechanisms and Laboratory of Molecular Immunopharmacology, Kunming Institute of Zoology, Chinese Academy of
Sciences; Kunming 650223, Yunnan, P. R. China: c Graduate School of the Chinese Academy of Sciences; Beijing 100039,
P. R. China: and d Key Laboratory of Tobacco Chemistry of Yunnan Province, Yunnan Academy of Tobacco Science;
Kunming 6501064, Yunnan, P. R. China.
Received January 13, 2010; accepted February 9, 2010; published online March 12, 2010
A new nortriterpenoid, 20-hydroxymicrandilactone D (1) and a novel lignan glycoside, lancilignanside A (2)
were isolated from leaves and stems of Schisandra lancifolia, together with three known nortriterpenoids (3—5)
and nine known phenolics (6—14). The structures of new compounds 1 and 2 were determined by detailed analy-
sis of their 1D and 2D NMR spectra, and chemical evidences. In addition, compounds 1—2, 6—7, and 9—11
showed anti-human immunodeficiency virus (HIV)-1 activities with 50% effective concentration (EC50) in the
range of 3.0—99.0 mg/ml. Compound 12 was not bioactive in this assay with EC50 more than 200 mg/ml.
Key words nortriterpenoid; lignan; Schisandra lancifolia; anti-human immunodeficiency virus-1 activity
Plants of the genus Schisandra (Schisandraceae) is eco- Results and Discussion
nomically and medicinally valuable and is used widely in tra-
Compound 1 gave a quasi-molecular ion at m/z 599
ditional Chinese medicines. They were proved to be rich [MꢀNa]ꢀ in its positive electrospray ionization (ESI)-MS
sources of bioactive lignans, which possessed various benefi- spectrum and possessed a molecular formula of C29H36O12,
cial pharmacological effects such as antihepatitis, antitumor which was confirmed by HR-ESI-MS (Found [MꢀNa]ꢀ
and anti-human immunodeficiency virus (HIV-1) activity.1—5) 599.2213, Calcd 599.2207). Its H-NMR spectrum showed
1
During the past 10 years, great efforts of our group have five tertiary methyl signals. Its 13C- and distortionless en-
been devoted to the phytochemical investigations on more
than 10 medicinal plants of the genus Schisandra. A series of
structurally attractive nortriterpenoids have been isolated
so far, which can be mainly divided into schiartane, 18-
norschiartane, 18(13→14)-abeo-schiartane, schisanartane,
pre-schisanartane and wuweiziartane types.6) Some of them
7—9)
exhibited modest or strong anti-HIV activities
and cyto-
toxicity.10,11)
Schisandra lancifolia (REHD. et WILS) A. C. SMITH, is a
climbing plant mainly distributed in Mainland of China. Our
previous research on this plant collected from Yunnan region
of China led to the discovery of some new highly oxygenated
nortriterpenoids.8,9,12—16) Reinvestigation of the leaves and
stems of this plant led to the isolation of a new nortriter-
penoid, 20-hydroxymicrandilactone D (1), and a novel lignan
glycoside, lancilignanside A (2), together with three known
triterpenoids, micrandilactone A (3),17) micrandilactone D
(4),18,19) and lancifodilactone L (5),12) and nine known pheno-
lics including 4,4-di(4-hydroxy-3-methoxyphenyl)-2,3-di-
methylbutanol (6),20) (ꢀ)-1-hydroxypinoresinol (7),21) prinse-
piol (8),22) evofolin (9),23) balaphonin (10),24) phyllocoumarin
(11),25) (ꢁ)-epicatechin (12),26) quercetin (13),27) and
3,4ꢂ,5,7-tetrahydroxyflavone (14) (Fig. 1).28) The structures
of 1 and 2 were determined by extensive NMR spectroscopic
experiments, including 1H–1H correlation spectroscopy
(COSY), heteronuclear single quantum coherence (HSQC),
heteronuclear multiple bond correlation (HMBC), and rotat-
ing frame Overhauser enhancement spectroscopy (ROESY)
techniques, together with chemical evidences. In addition,
some isolates were evaluated for anti-HIV activity. The pres-
ent paper reports the isolation, structural elucidation, and bi-
ological evaluation of the new compounds.
Fig. 1. Structures of Compounds 1—14
© 2010 Pharmaceutical Society of Japan
∗ To whom correspondence should be addressed. e-mail: hdsun@mail.kib.ac.cn

June 2010
853
Table 1. 1H- and 13C-NMR Data for Compounds 1 and 2a)
1
2
Position
Position
dC
dH
dC
dH
1
81.5 d
35.0 t
4.20 (d, 6.1)
2.69 (d, 15.4)
2.85 (dd, 6.1, 15.4)
1
2
3
4
5
6
7
8
9
138.4 s
107.4 d
148.4 s
148.2 s
115.4 d
120.4 d
83.3 d
2a
2b
3
4
5
6a
6b
7
8
9
6.99 (d, 1.3)
174.9 s
84.0 s
58.2 d
36.6 t
6.76 (d, 8.0)
6.92 (d, 1.3, 8.0)
5.01 (d, 8.2)
2.40 (m)
3.57 (overlapped)
3.98 (dd, 4.4, 9.6)
2.51 (dd, 3.5, 10.5)
2.19 (m)
2.05 (m)
4.60 (m)
3.02 (d, 7.7)
52.6 d
69.4 t
67.9 d
60.3 d
82.4 s
95.7 s
41.4 t
1ꢂ
2ꢂ
3ꢂ
4ꢂ
5ꢂ
6ꢂ
7ꢂ
8ꢂ
9ꢂ
135.3 s
110.8 d
147.6 s
146.8 s
108.5 d
120.0 d
83.5 d
10
7.05 (d, 1.7)
11a
11b
12a
12b
13
14
15
16
17
2.10 (m)
1.75 (m)
1.62 (m)
1.90 (m)
30.8 t
6.80 (d, 8.1)
6.88 (dd, 1.7, 8.1)
4.94 (d, 8.6)
2.28 (m)
3.58 (overlapped)
3.70 (m)
4.27 (d, 7.1)
3.16 (overlapped)
3.35 (t, 7.6)
3.46 (overlapped)
3.45 (overlapped)
3.18 (overlapped)
3.79 (dd, 5.7, 10.8)
3.83 (s)
49.3 s
44.8 d
98.5 s
208.2 s
220.2 s
26.7 q
42.6 t
2.93 (d, 8.3)
55.2 d
61.4 t
G-1
G-2
G-3
G-4
G-5
G-6
104.6 d
74.2 d
77.3 d
70.7 d
77.3 d
66.2 t
18
1.03 (s)
2.19 (AB d, 12.9)
2.51 (AB d, 12.9)
19a
19b
20
21
22
23
24
25
26
74.9 s
24.5 q
41.9 d
73.5 d
76.5 d
76.5 s
177.2 s
17.5 q
21.0 q
29.8 q
1.55 (s)
3.27 (d, 8.3)
5.61 (br s)
5.20 (br s)
OMe
OCH2O
56.2 q
101.8 t
5.97 (s)
27
29
30
1.70 (s)
1.10 (s)
1.25 (s)
a) Data were recorded in C5D5N for 1 and in acetone-d6 for 2 at 125 MHz (13C-NMR) and 500 MHz (1H-NMR); chemical shifts (d) are expressed in ppm.
hancement by polarization transfer (DEPT) NMR data
showed the signals for 29 carbons, including two ester
groups, two ketone groups, seven quaternary carbons (six
oxygenated ones), eight methines (four oxygenated ones),
four methylenes, and five methyls (Table 1). This hint that 1
was a highly oxygenated nortriterpene and contained eight
1
rings. Analysis of the H- and 13C-NMR data of 1 revealed
Fig. 2. Selected HMBC (→) and 1H–1H COSY (—) Correlations of 1 and
2
that they are similar to those reported for micrandilactone D
(4),18,19) which was also isolated in this plant. Comparison of
1
1D NMR data, together with detailed HMBC and H–1H therefore, OH-25 was a-oriented. Thus, compound 1 was de-
COSY analyses indicated that the difference was due to a termined to be a 20-hydroxy derivative of micrandilactone D,
methine (C-25) in 4 was replaced by an oxygenated quater- and gave the name as 20-hydroxymicrandilactone D.
nary carbon (C-25, dC 76.5) in 1 (Fig. 2). This was confirmed
Compound 2, [a]D25.5 ꢀ12.5° (cꢃ0.115, CH3OH), was iso-
by HMBC correlations from Me-27 (dH 1.70, s) to C-25 (dC lated as an amorphous powder. The molecular formula was
76.5), C-24 (dC 76.5), and C-26 (dC 177.2).
determined to be C26H31O11 by HR-ESI-MS (Found [MꢀH]ꢀ
1
The relative stereochemistry of 1 was established by analy- 519.1782, Calcd 519.1788). The H-NMR spectrum showed
sis of its ROESY NMR data and chemical shift comparison obvious signals due to two methines [dH 2.40 (1H, m, H-8 ),
with those of micrandilactone D.18,19) Biogenetically, H-C(5) 2.28 (1H, m, H-8ꢂ)], one methoxyl group (dH 3.83, 3H, s),
was a- and Me(18) was b-oriented.18,19) The ROESY correla- one methylenedioxy group (dH 5.97, 2H, s), an anomeric
tion of H-5 with H-7 indicated a-orientation of H-7 (Fig. 3). proton (dH 4.27, 1H, d, Jꢃ7.1 Hz), and two sets of 1,3,4-
Accordingly, OH-7 was assigned as b-oriented. ROESY cor- trisubstituted benzene protons [dH 6.99 (1H, d, Jꢃ1.3 Hz, H-
relations of Me-18 with H-14, H-22, and Me-21 indicated 2), 6.76 (1H, d, Jꢃ8.0 Hz, H-5) , 6.92 (1H, dd, Jꢃ1.3,
that H-14, H-22, and Me-21 were on the same face and all 8.0 Hz, H-6), 7.05 (1H, d, Jꢃ1.7 Hz, H-2ꢂ), 6.80 (1H, d,
were b-oriented. In addition, ROESY correlations of Me-27 Jꢃ8.1 Hz, H-5ꢂ), 6.88 (1H, dd, Jꢃ1.7, 8.1 Hz, H-6ꢂ)] (Table
with H-14 and H-22 indicated Me-27 was b-oriented and 1). The 13C- and DEPT NMR spectra showed signals due to

854
Vol. 58, No. 6
Table 2. Summary of Cytotoxicities and Anti-HIV-1 Activities
Cytotoxicity
Anti-HIV-1IIIB activitiy Selectivity index
Compounds
CC50 (mg/ml)a)
EC50 (mg/ml)
CC50/EC50
1
2
6
7
9
10
11
12
ꢄ200
ꢄ200
ꢄ200
ꢄ200
109.7
12.6
99.0
76.8
10.5
79.4
37.2
3.0
ꢄ2.0
ꢄ2.6
9.5
ꢄ2.5
3.0
4.3
4.6
ꢄ200
ꢄ200
43.7
ꢄ200
a) Minimal cytotoxicity against C8166 cells when CC50 ꢄ200 (mg/ml).
tion between C-8 and C-8ꢂ was established as trans-configu-
ration by ROESY correlations of H-8 with H-9ꢂ, H-8ꢂ with
H-9, and no ROESY correlation observed between H-8 and
H-8ꢂ. Thus, the structure of 2 was established, and given the
trivial name, lancilignanside A.
The anti-HIV-1 activities of compounds 1—2, 6—7, and
9—12 were evaluated in preventing the cytopathic effects of
HIV-1 in C8166, and cytotoxicity was measured in parallel
with the determination of antiviral activity using azidothymi-
Fig. 3. Key ROESY Correlations of 1 and 2
twelve aromatic carbons, two methines (C-8 and C-8ꢂ), two dine (AZT) as a positive control (50% effective concentra-
oxymethines (C-7 and C-7ꢂ), two oxymethylenes (C-9 and C- tion (EC50)ꢃ0.0033 mg/ml and CC50ꢄ200 mg/ml).31) Com-
9ꢂ), one methoxyl group, one methylenedioxy group, and six pounds 1—2, 6—7, and 9—12 exerted minimal cytotoxicity
carbon signals due to a hexose (Table 1). From these func- against C8166 cells (CC50ꢄ200 mg/ml) and compounds 1—
tionalities, the aglycone suggested a 2,5-diaryltetrahydrofura- 2, 6—7, and 9—11 showed anti-HIV-1 activities with EC50
noid-type lignan.29,30) In addition, HMBC correlations from values in the range of 3.0—99.0 mg/ml. Compound 12 was
the protons of one methoxyl group (dH 3.83, 3H, s) to C-3 not bioactive in this assay with EC50 value more than
(dC 148.4) showed that the methoxyl group was located at C- 200 mg/ml (Table 2).
3, which was further confirmed by the ROESY correlation of
the methoxyl group protons with H-2. HMBC correlations of
Experimental
General Experimental Procedures Optical rotations were measured
with a Horiba SEPA-300 polarimeter. UV spectra were obtained using a Shi-
madzu UV-2401A spectrophotometer. A Tenor 27 spectrophotometer was
protons of one methylenedioxy group with C-3ꢂ and C-4ꢂ de-
termined the methylenedioxy group was located between C-
3ꢂ and C-4ꢂ. The hexose was deduced to be glucose by the
comparison of chemical shifts of sugar unit with those of
7S,7ꢂS,8R,8ꢂR-icariol A2-9-O-b-D-glucopyranoside,29) and
was further confirmed by acid hydrolysis of 2, which af-
forded D-glucose. The glucose was unambiguously assigned
to C-9 (dC 69.4) due to the obvious 1H–13C long-range corre-
used for scanning IR spectroscopy with KBr pellets. 1D and 2D NMR spec-
tra were recorded on DRX-500 spectrometers with TMS as internal stan-
dard. Unless otherwise specified, chemical shifts (d) were expressed in ppm
with reference to the solvent signals. HR-ESI-MS was performed on an API
QSTAR time-of-flight spectrometer and a VG Autospec-3000 spectrometer,
respectively. Preparative HPLC was performed on a Shimadzu LC-8A
preparative liquid chromatograph with a ZORBAX PrepHT GF (21.2 mmꢅ
lations between the anomeric proton of glucose and C-9 and 25 cm, 7 mm) column. Column chromatography was performed with Si gel
(200—300 mesh, Qing-dao Marine Chemical, Inc., Qingdao, China),
between H-9 and the anomeric carbon of glucose (Fig. 2).
The anomeric proton was determined to be b-configuration
on the basis of the large coupling constants of the anomeric
Lichroprep RP-18 gel (40—63 mm, Merck, Darmstadt, Germany). The frac-
tions were monitored by TLC, and spots were visualized by heating Si gel
plates sprayed with 5% H2SO4 in EtOH.
Plant Material The leaves and stems of S. lancifolia were collected in
protons (dH 4.27, d, Jꢃ7.1 Hz). Furthermore, HMBC corre-
Dali Prefecture, Yunnan Province, People’s Republic of China, in August
2006. The specimen was identified by Prof. Xi-Wen Li and a voucher speci-
men (No. KIB 2006-08-14) has been deposited at the State Key Laboratory
of Phytochemistry and Plant Resources in West China, Kunming Institute of
Botany, Chinese Academy of Sciences.
lation of G-6 protons of the glucose with C-4 showed the
glucose was further connected with C-4 through G-6, which
was also supported by the downfield shift of G-6 to dC 66.2.
Therefore, the planar structure was established as shown.
The relative stereochemistry of 2 was established by analy-
sis of its ROESY NMR data and comparisons of coupling
constants of H-7 and H-7ꢂ and chemical shifts with those of
7S,7ꢂS,8R,8ꢂR-icariol A2-9-O-b-D-glucopyranoside.29) The
relative configurations between C-7 and C-8, and between C-
7ꢂ and C-8ꢂ were both established as trans-configurations by
ROESY correlations of H-7 with H-9, and H-7ꢂ with H-9ꢂ,
respectively, which also supported by the similarity of cou-
pling constants of H-7 (Jꢃ8.2 Hz) and H-7ꢂ (Jꢃ8.6 Hz) with
those of 7S,7ꢂS,8R,8ꢂR-icariol A2-9-O-b-D-glucopyranoside
Extraction and Isolation The leaves and stems of S. lancifolia (2.5 kg)
was ground and exhaustively extracted with 70% aqueous Me2CO at room
temperature. The solvent was evaporated in vacuo, and the crude extract
(170 g) was dissolved in H2O and partitioned with EtOAc. The EtOAc por-
tion (78 g) was chromatographed on a silica gel column eluting with
CHCl3–Me2CO (1 : 0, 9 : 1, 8 : 2, 2 : 1, 1 : 1, 0 : 1) to afford fractions A—F.
Fraction B (13.4 g) was repeatedly chromatographed on silica gel (200—300
mesh) and Sephadex LH-20, and finally by semi-preparative HPLC
(MeOH : H2O, 45 : 55) to yield compounds 2 (7 mg), 6 (8 mg), and 11
(9 mg). Fraction C (15.6 g) was chromatographed on a silica gel column
eluting with CHCl3–MeOH (10 : 1, 5 : 1, 2 : 1, 1 : 1) to afford five fractions.
Fraction C-1 (3.1 g) was purified by recrystallization and repeated chro-
(H-7, Jꢃ8.3 Hz; H-7ꢂ, Jꢃ8.5 Hz).29) The relative configura- matography over silica gel, RP-18 and Sephadex LH-20 (MeOH), and fol-

June 2010
855
lowed by semi-preparative and preparative HPLC (MeOH : H2O, 35 : 65 and
MeOH : CH3CN : H2O, 15 : 33 : 52) to yield compounds 1 (5 mg), 3 (6 mg), 5
(9 mg), 10 (18 mg), and 14 (44 mg). Similarly, Fraction C-2 (2.6 g) and C-3
(1.4 g) were respectively purified using the chromatography methods above-
mentioned, to yield compounds 4 (10 mg), 7 (26 mg), 8 (2 mg), 9 (9 mg), 12
(20 mg), and 13 (16 mg).
25, 871—891 (2008).
7) Li R. T., Han Q. B., Zheng Y. T., Wang R. R., Yang L. M., Lu Y., Sang
S. Q., Zheng Q. T., Zha Q. S., Sun H. D., Chem. Commun., 2005,
2936—2938 (2005).
8) Xiao W. L., Li R. T., Li S. H., Li X. L., Sun H. D., Zheng Y. T., Wang
R. R., Zheng Q. T., Org. Lett., 7, 1263—1266 (2005).
Compound 1: White powder. [a]D25.4 ꢀ51.1° (cꢃ0.101, CH3OH). UV
(CH3OH): lmax (log e) 202 (3.35) nm. IR (KBr): nmax 3455, 2925, 2846,
9) Xiao W. L., Zhu H. J., Shen Y. H., Li R. T., Li S. H., Sun H. D., Zheng
Y. T., Zheng Q. T., Org. Lett., 7, 2145—2148 (2005).
1768, 1632, 1378, 1125, 1019, 578 cmꢁ1. Positive ESI-MS m/z: 599 10) Xiao W. L., Lei C., Ren J., Liao T. G., Pu J. X., Pittman C. U. Jr., Lu
[MꢀNa]ꢀ. HR-ESI-MS m/z: 599.2213 [MꢀNa]ꢀ (Calcd 599.2207 for
Y., Zheng Y. T., Zhu H. J., Sun H. D., Chem. Eur. J., 14, 11584—
C29H36O12Na). NMR data: see Table 1.
11592 (2008).
Compound 2: Amorphous powder. [a]D25.5 ꢀ12.5° (cꢃ0.115, CH3OH). 11) Xiao W. L., Gong Y. Q., Wang R. R., Weng Z. Y., Luo X., Li X. N.,
UV (CH3OH): lmax (log e) 210 (3.87), 240 (3.65), 272 (3.1) nm. IR (KBr):
nmax 3455, 2925, 2877, 1771, 1726, 1622, 1460, 1167, 1075, 1021,
Yang G. Y., He F., Pu J. X., Yang L. M., Zheng Y. T., Lu Y., Sun H. D.,
J. Nat. Prod., 72, 1678—1681 (2009).
879 cmꢁ1. Positive ESI-MS m/z: 519 [MꢀH]ꢀ. HR-ESI-MS m/z: 519.1782 12) Xiao W. L., Huang S. X., Zhang L., Tian R. R., Wu L., Li X. L., Pu J.
[MꢀH]ꢀ (Calcd 519.1788 for C26H31O11). NMR data: see Table 1.
Acid Hydrolysis of Compound 2 A solution of 2 (3.5 mg) in 2 M HCl
(4 ml) was heated in a water bath at 80 °C for 6 h. After cooling, the reaction
X., Sun H. D., J. Nat. Prod., 69, 650—653 (2006).
13) Xiao W. L., Tian R. R., Pu J. X., Li X., Wu L., Lu Y., Li S. H., Sun H.
D., J. Nat. Prod., 69, 277—279 (2006).
mixture was neutralized with NaHCO3 and extracted with CHCl3. We were 14) Li R. T., Xiang W., Li S. H., Lin Z. W., Sun H. D., J. Nat. Prod., 67,
not able to get the aglycone of 2 unfortunately, because the TLC inspec- 94—97 (2004).
tion of the CHCl3 part indicated that at least four products were yielded, 15) Li R. T., Li S. H., Zhao Q. S., Lin Z. W., Sun H. D., Lu Y., Wang C.,
which were not subjected to further isolation and identification due to Zheng Q.-T., Tetrahedron Lett., 44, 3531—3534 (2003).
limited amount. However, through co-TLC with authentic sample using 16) Xiao W. L., Huang S. X., Wang R. R., Zhong J. L., Gao X M., He F.,
CHCl3–MeOH–H2O–HOAC (7 : 3 : 0.8 : 1) as developing system, glucose Pu J. X., Zheng Q. T., Phytochemistry, 69, 2862—2866 (2008).
was detected in the water layer (Rfꢃ0.49), which was further concentrated to 17) Li R. T., Zhao Q. S., Li S. H., Han Q. B., Sun H. D., Lu Y., Zhang L.
dryness and subjected to silica gel chromatography eluting with L., Zheng Q. T., Org. Lett., 5, 1023—1026 (2003).
CHCl3–MeOH (1 : 1) to give purified D-glucose (0.9 mg): [a]D18.8 ꢀ24.7 18) Li R. T., Xiao W. L., Shen Y. H., Zhao Q. S., Sun H. D., Chem. Eur. J.,
(cꢃ0.12, H2O). 11, 2989—2996 (2005).
Anti-HIV-1 Assay The anti-HIV activities and cytotoxicities were as- 19) Li R. T., Xiao W. L., Shen Y. H., Zhao Q. S., Sun H. D., Chem. Eur. J.,
sessed by microtiter syncytium formation infectivity assay, using the method
11, 6763 (2005).
previously described, with AZT as a positive control.31)
20) Xu L. J., Huang F., Chen S. B., Li L. N., Chen S. L., Xiao P. G., J. In-
tegr. Plant Biol., 48, 1493—1497 (2006).
Acknowledgments This project was supported financially by the NSFC 21) Tsukamoto H., Hisada S., Nishibe S., Chem. Pharm. Bull., 32, 2730—
(No. 20802082 and 30830115), the projects from the Chinese Academy of 2735 (1984).
Sciences (“Xibuzhiguang” to W.-L.X and No. KSCX1-YW-R-24), the Yong 22) Kilidhar S. B., Parthasarathy M. R., Sharma P., Phtocheminstry, 21,
Academic and Technical Leader Rising Foundation of Yunnan Province 796—797 (1982).
(2006PY01-47), and the Major State Basic Research Development Program 23) Wu T. H., Yer J. H., Wu P. L., Phytochemistry, 40, 121—124 (1995).
of China (No. 2009CB522300 and 2009CB940900).
24) Alicia B., Susana M., Cesar A. N., Jesus G. D., Werner H., Phytochem-
istry, 34, 253—259 (1993).
References
25) Foo L. Y., Phytochemistry, 28, 2477—2481 (1989).
1) Chen Y. G., Ping W., Lin Z. W., Sun H. D., Qin G. W., Xie Y. Y., Phy- 26) Markham K. R., Tetrahedron, 32, 2607—2612 (1976).
tochemistry, 48, 1059—1062 (1998).
2) Chen Y. G., Xie Y. Y., Cheng K. F., Cheung K. K., Qin G. W., Phyto-
chemistry, 58, 1277—1280 (2001).
3) Kuo Y. H., Kuo L. M., Chen C. F., J. Org. Chem., 62, 3242—3245
(1997).
4) Chen D. F., Zhang S. X., Wang H. K., Zhang S. Y., Sun Q. Z.,
Cosentino L. M., Lee K. H., J. Nat. Prod., 62, 94—97 (1999).
5) Sun H. D., Qiu S. X., Lin L. Z., Wang Z. Y., Lin Z. W., Pengsuparp T.,
27) Shen C. C., Chang Y. S., Hott L. K., Phytochemistry, 34, 843—845
(1993).
28) Markham K. R. Ternai B., Stanley R., Markham K. R., Geiger H.,
Mabry T. J., Tetrahedron, 34, 1389—1397 (1978).
29) Yamauchi H., Kakuda R., Yaoita Y., Machida K., Kikuchi M., Chem.
Pharm. Bull., 55, 346—347 (2007).
30) Kanchanapoom T., Kamel M. S., Kasai R., Yamasaki K., Picheansoon-
thon C., Hiraga Y., Phytochemistry, 56, 369—372 (2001).
Pezzuto J. M., Fong H. H., Cordell G. A., Farnsworth N. R., J. Nat. 31) Wang J. H., Tam S. C., Huang H., Ouyang D. Y., Wang Y. Y., Zheng Y.
Prod., 59, 525—527 (1996).
T., Biochem. Biophys. Res. Commun., 317, 965—971 (2004).
6) Xiao W. L., Li R. T., Huang S. X., Pu J. X., Sun H. D., Nat. Prod. Rep.,