Three new monomeric indole alkaloids from the roots of Catharanthus roseus

Article abstract of DOI:10.1080/10286020.2011.649728

Two new alkaloid glycosides (1 and 2) and a new monomeric indole alkaloid (3), together with 13 known ones (4-16), were isolated from the roots of Catharanthus roseus. The structures of new compounds were elucidated on the basis of the spectroscopic methods. The absolute configuration of compound 3 was established by the modified Mosher's method.

Full text of DOI:10.1080/10286020.2011.649728

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Three new monomeric indole alkaloids
from the roots of Catharanthus roseus
Chun-Hua Wang a b , Guo-Cai Wang b c , Ying Wang b c , Xiao-Qi
Zhang b c , Xiao-Jun Huang b c & Wen-Cai Ye a b c
a Department of Natural Medicinal Chemistry , China
Pharmaceutical University , Nanjing , 210009 , China
b Institute of Traditional Chinese Medicine and Natural Products,
College of Pharmacy, Jinan University , Guangzhou , 510632 ,
China
c Guangdong Province Key Laboratory of Pharmacodynamic
Constituents of TCM and New Drugs Research, Jinan University ,
Guangzhou , 510632 , China
Published online: 14 Feb 2012.
To cite this article: Chun-Hua Wang , Guo-Cai Wang , Ying Wang , Xiao-Qi Zhang , Xiao-Jun Huang
& Wen-Cai Ye (2012) Three new monomeric indole alkaloids from the roots of Catharanthus roseus ,
Journal of Asian Natural Products Research, 14:3, 249-255, DOI: 10.1080/10286020.2011.649728
To link to this article: http://dx.doi.org/10.1080/10286020.2011.649728
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Journal of Asian Natural Products Research
Vol. 14, No. 3, March 2012, 249–255
Three new monomeric indole alkaloids from the
roots of Catharanthus roseus
Chun-Hua Wangab†, Guo-Cai Wangbc†, Ying Wangbc, Xiao-Qi Zhangbc, Xiao-Jun Huangbc
and Wen-Cai Yeabc
*
aDepartment of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009,
China; Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy,
b
c
Jinan University, Guangzhou 510632, China; Guangdong Province Key Laboratory of
Pharmacodynamic Constituents of TCM and New Drugs Research, Jinan University,
Guangzhou 510632, China
(Received 6 October 2011; final version received 12 December 2011)
Two new alkaloid glycosides (1 and 2) and a new monomeric indole alkaloid (3),
together with 13 known ones (4–16), were isolated from the roots of Catharanthus
roseus. The structures of new compounds were elucidated on the basis of the
spectroscopic methods. The absolute configuration of compound 3 was established by
the modified Mosher’s method.
Keywords: Catharanthus roseus; Apocynaceae; indole alkaloid glycoside; Mosher’s
method
1. Introduction
2. Results and discussion
The plant Catharanthus roseus (Apocyna-
ceae) is widely distributed in tropical and
semitropical regions. Up to now, over 130
indole alkaloids have been isolated from
this plant [1]. Vinblastine and vincristine
are the two typical indole alkaloids isolated
from this plant in the 1950–1960s [2,3],
which were used in clinic for the treatment
of various leukemias, Hodgkin’s disease,
and solid tumors [4]. With the aim of
searching for indole alkaloids with high
biological activities, we had isolated some
new indole alkaloids from the aerial parts
of this plant [5,6]. Recently, we have
carried out the phytochemical investi-
gations on the roots of this plant. This
paper reports the isolation and structural
elucidation of three new alkaloids (1–3)
(Figure 1) from the roots of C. roseus,
together with 13 known ones (4–16).
Compound 1 was obtained as an amor-
phous powder. The molecular formula of 1
was determined as C26H34N2O7 on the
basis of its HR-ESI-MS at m/z 487.2429
[M þ H]þ. The IR spectrum of 1 implied
the presence of hydroxyl group
(3357 cm21), ester group (1730 cm21),
and double bond (1594 cm21). The 1H
NMR spectrum showed three aromatic
protonsat dH 6.82 (1H, dd, J ¼ 8.5, 2.5 Hz),
6.73 (1H, d, J ¼ 2.5 Hz), and 6.56 (1H, d,
J ¼ 8.5 Hz); an olefinic proton at dH 5.48
(1H, q, J ¼ 7.0 Hz); three methyl groups at
dH 3.80 (3H, s), 2.65 (3H, s), and 1.52 (3H,
d, J ¼ 7.0 Hz); and an anomeric proton at
dH 4.61 (1H, d, J ¼ 7.5 Hz). Accordingly,
the 13C NMR spectrum of 1 displayed the
signals for an aromatic ring (dC 153.2,
150.1, 142.6, 116.9, 112.4, and 111.4), a
pair of olefinic carbons (dC 138.5 and
*Corresponding author. Email: chywc@yahoo.com.cn
†The authors contributed equally to this work.
ISSN 1028-6020 print/ISSN 1477-2213 online
q 2012 Taylor & Francis
http://dx.doi.org/10.1080/10286020.2011.649728
http://www.tandfonline.com

250
C.-H. Wang et al.
COOCH3
3
COOCH3
4
H 16
16
H
14
19
5
6
N
9
9
6
6
H 15
20
10
10
8
O
8
7
2
7
9
O
5
5
OH
1'
1'
7
2
8
O
21
10
11
18
O
2
1
N
H
N 4
N 4
1
N
OH
3
5'
11
2'
13
OH 11
13
21
20
21
20
5'
1
HO
2'
3'
3
17
HO
12
12
13
N
H
4'
3'
H
12
16
4'
14
15
14
HO
19
18
HO
19
18
COOCH3
15
1
2
3
Figure 1. Chemical structures of compounds 1–3.
121.9), an ester carbonyl carbon (dC 174.5),
three methyls (dC 52.4, 35.5, and 13.7), and
an arabinopyranose unit (dC 104.4, 74.4,
72.5, 69.8, and 67.3).
of the absorption bands ascribable to
hydroxyl group (3367 cm21), ester
group (1733 cm21), and double bond
(1596 cm21). The 1H NMR spectrum
gave three protons due to aromatic ring
[dH 7.04 (1H, d, J ¼ 2.5 Hz), 6.81 (1H, dd,
J ¼ 8.0, 2.5 Hz), and 6.22 (1H, d,
J ¼ 8.0 Hz)]; one olefinic proton [dH 5.50
(1H, q, J ¼ 7.0 Hz)]; three methyl signals
[dH 3.78 (3H, s), 2.57 (3H, s), and 1.60
(3H, d, J ¼ 7.0 Hz)]; and an anomeric
proton [dH 4.59 (1H, d, J ¼ 7.0 Hz)]. The
13C NMR spectrum showed the presence
of an aromatic ring (dC 151.8, 146.6,
139.3, 118.0, 115.6, and 107.0), a pair of
olefinic carbons (dC 139.9 and 124.5), an
ester carbonyl carbon (dC 175.3), three
methyl groups (dC 51.9, 28.8, and 14.0),
and an arabinopyranose unit (dC 104.9,
74.4, 72.6, 69.8, and 67.2).
The aglycone and sugar unit were
obtained by acid hydrolysis of 1. The
spectral and the optical rotation data of
the aglycone were the same as those of
10-hydroxycathafoline [7], confirming
the aglycone was 10-hydroxycathafoline.
The sugar unit was derived and analyzed
by GC using authentic samples as refe-
rences, which suggested the sugar was
L-arabinopyranose. The coupling constant
(J ¼ 7.5 Hz) of the anomeric proton signal
indicated the presence of a-L-arabinopyr-
anosyl. The HMBC correlation between H-
10 (dH 4.61) and C-10 (dC 153.2) (Figure 2)
suggested that the arabinopyranose was
attached to C-10 position of 10-hydroxy-
cathafoline. Based on the above data, 1 was
determined to be 10-hydroxycathafoline
10-O-a-L-arabinopyranoside.
Acid hydrolysis of 2 afforded L-
arabinopyranose and aglycone, the agly-
cone was elucidated as 10-hydroxydefor-
modihydropseudoakuammigine [8,9] by
the comparison of its NMR spectral data.
The HMBC correlation between H-10 (dH
4.59) and C-10 (dC 151.8) (Figure 2)
indicated that the L-arabinopyranose unit
Compound 2 was obtained as an
amorphous powder. The molecular for-
mula C26H34N2O7 was established by its
HR-ESI-MS at m/z 487.2440 [M þ H]þ.
The IR spectrum showed the presence
COOCH3
H
COOCH3
H
N
H
N
O
O
H
OH
H
O
O
OH
N
H
N
H
OH
HO
N
HO
H
H
N
H
H
H
H
HO
H
HO
H
H3COOC
CH3
CH3
1
2
3
HMBC
ROESY
Figure 2. Key HMBC and ROESY correlations of 1–3.

Journal of Asian Natural Products Research
was attached to C-10 position of 10-
251
0.00
–0.05
hydroxydeformodihydropseudoakuammi-
gine. Hence, 2 was characterized as 10-
hydroxydeformodihydropseudoakuammi-
gine 10-O-a-L-arabinopyranoside.
–0.11
–0.05
N
+0.05
OAPTM
+0.06
0.00
+0.03
+0.02
+0.17
+0.15
Compound 3 was isolated as colorless
needles. The molecular formula was
determined as C21H26N2O3 on the basis
of its HR-ESI-MS at m/z 355.2019
[M þ H]þ. The IR spectrum of 3 showed
the characteristic absorptions due to
hydroxyl group (3374 cm21) and ester
+0.06
+0.04
N
H
+0.02
+0.03
COOCH3
+0.01
Figure 3. ed values (dS–dR) of the MTPA
esters 3a and 3b.
1
group (1707 cm21). The H NMR spec-
Consequently, 3 was elucidated as 15(S)-
hydroxy-14,15-dihydrovindolinine.
trum showed four protons for aromatic
ring [dH 7.27 (1H, dd, J ¼ 7.0, 1.0 Hz),
6.99 (1H, ddd, J ¼ 7.5, 7.0, 1.5 Hz), 6.74
(1H, ddd, J ¼ 8.0, 7.5, 1.0 Hz), and 6.67
(1H, dd, J ¼ 8.0, 1.5 Hz)], and two methyl
groups [dH 3.69 (3H, s) and 0.96 (3H, d,
J ¼ 7.0 Hz)]. The 13C NMR spectrum
displayed the signals of an aromatic ring
(dC 151.1, 139.4, 128.6, 124.6, 122.3, and
121.2), one ester carbonyl (dC 176.5), two
methyls (dC 52.5 and 7.4), and five
methylenes (dC 56.3, 44.9, 37.5, 32.2,
and 30.4). The above data indicated that 3
was an analog of vindolinine [10].
In addition, 13 known compounds
were identified by comparing their spectral
data with those of the literatures as
tetrahydroalstonine (4) [11], ajmalicine
(5) [12], vindorosine (6) [13], vindoline (7)
[14], 19(S)-vindolinine (8) [10], 19(R)-
vindolinine (9) [10], (2)-vincapusine (10)
[15], yohimbine (11) [12], serpentine (12)
[16], 18b-hydroxy-3-epi-a-yohimbine
(13) [17], sitsirikine (14) [18], perivine
(15) [19], and dihydroantirhine (16) [20],
respectively.
Detailed comparison of NMR spectral
data of 3 with those of 19(R)-vindolinine
[10] revealed that the NMR data of two
compounds were similar, except the
absence of a double bond at C-14 and C-
15 in 3, suggesting that C-14 or C-15 in 3
may be substituted by a hydroxyl
group. The HMBC correlations between
H-15 (dH 3.91) and C-14 (dC 32.2)/C-3 (dC
56.3)/C-19 (dC 49.7) (Figure 2) indicated
that the hydroxyl group was attached at C-
15 position. The relative configuration of 3
was assigned by the ROESY correlations
(Figure 2). The absolute configuration of
C-15 could be confirmed by the modified
Mosher’s method. Differences of proton
chemical shift (ed values, dS 2 dR)
3. Experimental
3.1 General experimental procedures
Melting points were recorded on an X-5
micro melting point apparatus without
correction. Optical rotations were deter-
minedonaJASCOP-1020 polarimeter. UV
spectra were obtained on a JASCO V-550
UV–vis spectrophotometer. IR spectra
were recorded on a JASCO FT/IR-480
plus spectrometer. H, 13C, and 2D NMR
1
spectra were determined on a Bruker AV-
500 spectrometer in CD3OD. ESI-MS were
run on a HP-1100 HPLC/EST spec-
trometer. HR-ESI-MS data were detected
on an Agilent 6210 ESI/TOF mass spec-
trometer. For column chromatography
(CC), silica gel (200–300 mesh, Qingdao
Marine Chemical Factory, Qingdao,
China), Sephadex LH-20 (Pharmacia Bio-
tec AB, Uppsala, Sweden), and Octadecyl-
silyl (ODS) (YMC, Kyoto, Japan) were
between
(S)-a-methoxy-a-(trifluoro-
methyl)phenylacetyl ester (3a) and (R)-a-
methoxy-a-(trifluoromethyl)phenylacetyl
ester (3b) (Figure 3) indicated the
presence of S configuration at C-15 in 3.

252
C.-H. Wang et al.
used. TLC analyses were carried out using
precoated silica gel GF254 plates (Qingdao
Marine Chemical Factory). HPLC separ-
ations were carried out on a COSMOSIL
(16 mg), 11 (12 mg), 12 (16 mg), and 13
(10 mg). The same methods were used to
isolate 15 (11 mg) and 16 (8 mg) from
fraction 4 (11.0 g), as well as 14 (12 mg)
from fraction 5 (8.5 g), respectively.
C18
preparative
column
(5 mm,
20 £ 250 mm, Nacalai Tesque, Kyoto,
Japan). L-Arabinopyranose was purchased
from Sigma (St Louis, MO, USA).
3.3.1 10-Hydroxycathafoline 10-O-a-L-
arabinopyranoside (1)
An amorphous powder, mp 204–2068C.
22
3.2 Plant material
½aꢀD þ 29.3 (c ¼ 0.14, MeOH). UV
(MeOH) lmax (log 1): 210 (1.47), 243
(1.97), 302 (1.55) nm. IR (KBr) nmax
The roots of C. roseus were collected in
Haikou City, Hainan Province of China, in
April 2009. The plant was authenticated by
Prof. Guang-Xiong Zhou of Jinan Univer-
sity. A voucher specimen (No. 0904011)
has been deposited in the Institute of
Traditional Chinese Medicine and Natural
Products, Jinan University, Guangzhou,
China.
:
3357, 1730, 1594, 1475, 1072, 762 cm21
.
For H and 13C NMR spectral data, see
Table 1. HR-ESI-MS m/z: 487.2429
[M þ H]þ (calcd for C26H35N2O7,
487.2439).
1
3.3.2 10-Hydroxydeformodihydro-
pseudoakuammigine 10-O-a-L-arabino-
pyranoside (2)
3.3 Extraction and isolation
An amorphous powder, mp 196–1988C.
22
The dried roots (12.5 kg) of C. roseus were
extracted with 95% EtOH. The solution
was evaporated in vacuo to get residue
(890 g). The residue was dissolved in H2O
to form a suspension, and then adjusted to
pH 3 with 6% HCl. The acidic suspension
was partitioned with CHCl3 to remove the
neutral components. The aqueous phase
was basified with 2% NH3·H2O to pH 10
and then extracted with CHCl3 to obtain a
total alkaloid part (130 g), 120 g of which
was subjected to silica gel CC (CHCl3–
CH3OH, 100:0 ! 0:100) to give nine
fractions. Fraction 1 (19.0 g) was subjected
to silica gel [petroleum ether (PE)–EtOAc,
9:1 ! 1:1] and Sephadex LH-20 (MeOH)
columns to afford 4 (22 mg), 5 (25 mg), 6
(20 mg), and 7 (36 mg). Fraction 2 (14.0 g)
was subjected to silica gel column (PE–
EtOAc, 9:1 ! 7:3) and purified by pre-
parative HPLC (MeOH–H2O, 88:12) to
yield 8 (25 mg) and 9 (18 mg). Fraction 3
(10.5 g) was subjected to ODS column
(MeOH–H2O, 20:80 ! 100:0) and pre-
parative HPLC (MeOH–H2O, 45:55) to
obtain 1 (14 mg), 2 (21 mg), 3 (18 mg), 10
½aꢀD 220.9 (c ¼ 0.11, MeOH). UV
(MeOH) lmax (log 1): 214 (2.13), 230
(2.25), 292 (1.96) nm. IR (KBr) nmax
:
3367, 1733, 1596, 1085, 794 cm21. For 1H
and 13C NMR spectral data, see Table 1.
HR-ESI-MS m/z: 487.2440 [M þ H]þ
(calcd for C26H35N2O7, 487.2439).
3.3.3 15(S)-Hydroxy-14,15-
dihydrovindolinine (3)
22
Colorless needles, mp 182–1848C. ½aꢀD
242.0 (c ¼ 0.15, MeOH). UV (MeOH)
lmax (log 1): 211 (0.68), 239 (1.15), 295
(0.69) nm. IR (KBr) nmax: 3374, 1707,
1607, 1466, 1214, 753 cm21. For H and
1
13C NMR spectral data see Table 1. HR-
ESI-MS m/z: 355.2019 [M þ H]þ (calcd
for C21H27N2O3, 355.2016).
3.4 Acid hydrolysis and GC analysis of
1 and 2
Compounds 1 and 2 (each 3.0 mg) were
dissolved in 2 mol/l HCl (1.0 ml) and
heated at 808C for 2 h, respectively. The

Journal of Asian Natural Products Research
253
d
d
d
d
d
d
d

254
C.-H. Wang et al.
aglycone was extracted with CH2Cl2, and
d
the aqueous layer was dried by N2. Dry
pyridine (1.0 ml) and L-cysteine methyl
ester hydrochloride (3.0 mg) were added to
the residue. The mixture was heated at
808C for 2 h and then dried by N2. N-
(Trimethylsilyl)imidazole (0.2 ml) was
added, and the mixture was heated at
808C for 1 h. Finally, H2O (1.0 ml) was
added to stop the reaction and the aqueous
layer was extracted with cyclohexane
(1.0 ml). The organic layer was analyzed
by GC analysis [column, AT-SE-30
(0.32 mm £ 30 m, 0.5 mm); detector, FID;
column temperature, 2208C; detector
temperature, 2708C; injector temperature,
2708C; and carrier gas, N2]. The standard
monosaccharides were subjected to the
same reaction and GC analysis under the
above conditions [tR (min): 22.142 (L-Ara)
and 23.278 (D-Ara)]. As a result, L-Ara [tR
(min): 22.139 and 22.141] was detected
from the hydrolyzates of 1 and 2,
respectively.
d
d
d
3.5 Preparation of a-methoxy-a-
(trifluoromethyl)phenylacetyl esters of 3
Compound 3 (4.0 mg) was dissolved in
0.5 ml pyridine, and treated with (R)-a-
methoxy-a-(trifluoromethyl)phenylacetyl
Cl (10 ml) for 24 h in an anhydrous
circumstance at room temperature. The
reaction mixture was poured into water
(5.0 ml) and extracted with EtOAc
(5.0 ml). The EtOAc extract was purified
by silica gel CC [n-hexane–EtOAc
(70:30)] to yield (S)-a-methoxy-a-(tri-
fluoromethyl)phenylacetyl ester (3a,
d
d
1.8 mg).
(R)-a-methoxy-a-(trifluoro-
methyl)phenylacetyl ester (3b, 1.6 mg)
was obtained using the same method by
the treatment of (S)-a-methoxy-a-(tri-
fluoromethyl)phenylacetyl Cl (10 ml).
(S)-a-methoxy-a-(trifluoromethyl)-
phenylacetyl ester (3a): 1H NMR
(CD3OD, 500 MHz) dH: 7.48 and 7.23
(phenyl protons of a-methoxy-a-(trifluor-
omethyl)phenylacetyl), 7.31 (1H, dd,

Journal of Asian Natural Products Research
255
[2] M. Gorman, N. Neuss, and G.H. Svoboda,
J. Am. Chem. Soc. 81, 4745 (1959).
[3] G.H. Svoboda, Lloydia 24, 173 (1961).
[4] M. Misawa, T. Endo, A. Goodbody,
J. Vukovic, C. Chapple, L. Choi, and
J.P. Kutney, Phytochemistry 27, 1355
(1988).
[5] G.C. Wang, X.Z. Zhong, D.M. Zhang,
Y. Wang, X.Q. Zhang, R.W. Jiang,
Y.L. Li, J. Wang, X.S. Yao, and W.C.
Ye, Planta Med. 77, 1739 (2011).
[6] X.Z. Zhong, G.C. Wang, Y. Wang,
X.Q. Zhang, and W.C. Ye, Acta Pharm
Sin. 45, 471 (2010).
[7] J. Balsevich, F. Constabel, and W.G.W.
Kurz, Planta Med. 44, 91 (1982).
[8] H. Meisel and W. Doepke, Tetrahedron
Lett. 17, 1285 (1971).
[9] M. Zhang, X.P. Huang, L.Q. Shen, and
Y. Qin, J. Am. Chem. Soc. 131, 6013
(2009).
[10] A.U. Rahman, M. Bashir, S. Kaleem, and
T. Fatima, Phytochemistry 22, 1021
(1983).
[11] S.F. Martin, J.E. Hunter, B. Benage,
L.S. Geraci, and M. Mortimoe, J. Am.
Chem. Soc. 113, 6161 (1991).
[12] E. Wenkert, C.J. Chang, H.P.S. Chawla,
D.W. Cochran, E.W. Hagaman, J.C. King,
and K. Orito, J. Am. Chem. Soc. 98, 3645
(1976).
[13] H. Ishikawa, G.I. Elliott, J. Velcicky,
Y. Choi, and D.L. Boger, J. Am. Chem.
Soc. 128, 10596 (2006).
J ¼ 7.0, 1.0 Hz, H-9), 7.09 (1H, ddd,
J ¼ 7.5, 7.0, 1.5 Hz, H-10), 6.86 (1H,
ddd, J ¼ 8.0, 7.5, 1.0 Hz, H-11), 6.78 (1H,
dd, J ¼ 8.0, 1.5 Hz, H-12), 5.48 (1H, t,
J ¼ 4.5 Hz, H-15), 3.67 (1H, overlapped,
H-21), 3.65 (3H, s, H-23), 3.60 (3H, s,
OMe of a-methoxy-a-(trifluoromethyl)-
phenylacetyl), 3.47 (1H, m, H-3a), 3.35
(1H, m, H-3b), 2.98 (1H, t, J ¼ 9.0 Hz,
H-16), 2.59 (1H, m, H-14a), 2.32 (1H,
overlapped, H-17a), 2.24 (1H, overlapped,
H-19), 2.18 (1H, m, H-14b), 1.72 (1H, m,
H-17b), 1.12 (3H, d, J ¼ 7.0 Hz, H-18);
ESI-MS m/z: 571 [M þ H]þ.
(R)-a-methoxy-a-(trifluoromethyl)-
phenylacetyl ester (3b): 1H NMR
(CD3OD, 500 MHz) dH: 7.47 and 7.23
(phenyl protons of a-methoxy-a-(trifluor-
omethyl)phenylacetyl), 7.26 (1H, dd,
J ¼ 7.0, 1.5 Hz, H-9), 7.06 (1H, ddd,
J ¼ 7.5, 7.0, 1.5 Hz, H-10), 6.84 (1H,
ddd, J ¼ 8.0, 7.5, 1.5 Hz, H-11), 6.75 (1H,
dd, J ¼ 8.0, 1.5 Hz, H-12), 5.42 (1H, t,
J ¼ 4.5 Hz, H-15), 3.67 (1H, overlapped,
H-21), 3.64 (3H, s, H-23), 3.60 (3H, s,
OMe of a-methoxy-a-(trifluoromethyl)-
phenylacetyl), 3.52 (1H, m, H-3a), 3.35
(1H, m, H-3b), 2.96 (1H, t, J ¼ 9.0 Hz, H-
16), 2.64 (1H, m, H-14a), 2.29 (1H,
overlapped, H-14b), 2.26 (1H, overlapped,
H-17a), 2.09 (1H, q, J ¼ 7.0 Hz, H-19),
1.68 (1H, m, H-17b), 0.95 (3H, d,
J ¼ 7.0 Hz, H-18); ESI-MS m/z: 571
[M þ H]þ.
[14] A. El-Sayed, G.A. Handy, and G.A.
Cordell, J. Nat. Prod. 46, 517 (1983).
´
´
[15] I. Moldvai, T. Gati, J.C. Szantay, and
S. Szantay, J. Org. Chem. 71, 3768
´
(2006).
[16] O. Wachsmuth and R. Matusch,
Phytochemistry 61, 705 (2002).
Acknowledgements
¨
[17] H. Falkenhagen and J. Stockigt,
This work was supported by grants from
Changjiang Scholars and Innovative Research
Team in the University (IRT0965) and
National Natural Science Foundation of
China (U 0932004; Nos 81001374, 30901848,
90913020).
Can. J. Chem. 71, 2201 (1993).
[18] G.M.T. Robort, A. Ahond, C. Poupat,
P. Potier, H. Jacquemin, and S.K. Kan,
J. Nat. Prod. 46, 708 (1983).
[19] P. Clivio, B. Richard, H.A. Hadi,
B. David, T. Sevenet, M. Zeches, and
L.L. Men-Oliver, Phytochemistry 29,
3007 (1990).
References
[20] G. Massiot, P. Thepenier, M.J. Jacquier,
L.L. Men-Olivier, and C. Dalande,
Phytochemistry 31, 2873 (1992).
[1] R.D. Heijden, D.I. Jacobs, W. Snoeijer,
D. Hallard, and R. Verpoorte, Curr. Med.
Chem. 11, 607 (2004).