全 文 ：A New Triterpenoid Saponin from Rhaponticum uniflorum (Compositae)
ZHANG Yong_Hong1 , LU Zhi_Gang2 , LI Xin_Pu2 , WANG Han_Qing1＊
(1.Lanzhou Institute of Chemical Physics , The Chinese Academy of Sciences , Lanzhou 730000 , China;
2.Lanzhou Insti tute of Animal Sciences and Animal Medicine , The Chinese Academy of Agricultural Sciences , Lanzhou 730050 , China)
Abstract:　A new triterpenoid saponin , namely unifloroside , together with five known compounds , was iso-
lated from Rhaponticum uniflorum (L.)DC.The structure of the new triterpenoid saponin was elucidated as
3_O_α_L_arabinopyranosyl_urs_9(11),12_dien_28_oic acid β_D_glucopyranosyl ester mainly by using 1D , 2D_
NMR techniques and chemical methods.
Key words:　Rhaponticum uniflorum ;Compositae;triterpenoid saponin;unifloroside
　　Rhaponticum uniflorum (L.)DC.(Compositae)is
distributed in northern China.Its root has been used as a
Chinese traditional medicine for treatment of fever and in-
toxications[ 1] .Phytochemical studies of this plant were
reported previously[ 2] .A continuation of our research on
the bioactive compounds of R.uniflorum has led to the
isolation of six triterpenoid saponins.One of them , 3_O_α_L_arabinopyranosyl_urs_9(11), 12_dien_28_oic acid β_
D_glucopyranosyl ester(3), was characterized as a new
compound.Their structures were determined by spectro-
scopic analysis(including 1D and 2D NMR techniques)
and chemical methods.
1　Results and Discussion
Compound 3 was obtained as platelet crystals , with
mp ranged 247-249 ℃.It gave a positive coloration in
the Liebermann_Burchard andMolish tests for triterpenoid
saponins.The IR spectrum showed the absorption for hy-
droxyl groups (3 437 cm-1), ester carbonyl (1 729
cm
-1)and double bond (1 645 cm-1).Acidic hydroly-
sis of compound 3 in refluxing 15%HCl containing some
benzene afforded D_glucose and L_arabinose.The
FABMS gave a peak at m/ z 771 [M+Na] + , HRFABMS
ion at m/z.748.439 4([M] + , calcd.748.439 2)de-
termined the molecular formula as C41H64O12.The 1H-
NMR spectrum of compound 3 showed the presence of two
trisubstituted double bonds.The two trisubstituted double
bonds forming a homoannular diene system was evident
from its UV absorption maximum at 280 nm characteristic
of such a system.The following 1H-NMR spectral data of
compound 3 suggested the structural feature of urs_9(11),
12_dien_28_oic acid bioside triterpenoid:a broad singlet
atδ1.97(H_18), two olefinic protons atδ5.70(d , J=10.6 Hz , H_11)and δ6.49 (d , J =10.6 Hz , H_
12), which were confirmed by the cross peaks between
H_11 and H_12 in the 1H_1H COSY spectrum , and H_29(δ0.75 , d , J =6.5 Hz , 3H), H_30(δ0.97 , d , J =
6.5 Hz , 3H)and two anomeric protons atδ6.20(d , J=8.1 Hz , glc_1)andδ4.75(d , J =7.0 Hz , ara_1).
The 13C-NMR spectrum showed four olefinic carbons atδ
135.49(s , C_9), 127.34(d , C_11)and 125.99(d ,
C_12), 138.25 (s , C_13), and a carboxyl carbon atδ
176.58(s , C_28).The assignments of the 13C-NMR sig-
nals of compound 3 were made by comparison with those
of model triterpenes
[ 3]
and were confirmed by the HMQC
and HMBC spectral analysis (Table 1).On the basis of
these data , the structure of compound 3was elucidated as
3_O_α_L_arabinopyranosyl_urs_9(11),12_dien_28_oic acidβ_D_glucopyranosyl ester(Fig.1), named unifloroside.
2　Experimental
2.1　General experimental procedures
Mp was obtained on a Kofler_microscope apparatus(uncorrected).IR spectra were recorded on a Nicolet_
5DX infrared spectrometer with KBr disc.UV spectra
were obtained with a Shimadzu UV 240 spectrometer.
1D_, 2D_1H and 13C-NMR spectra and NOESY experi-
ments in C5D5N were performed with a Bruker AM_400 ,
using TMS as internal standard.HRFABMS were carried
out with a Bruker APEXⅡ , and EIMS and FABMS were
recorded on a ZAB_HS mass spectrometer.
2.2　Plant materials
The roots of Rhaponticum uniflorum (L.)DC.were
purchased from the company of Chinese Medicinal Materi-
als in Gansu Province and were identified by Prof.ZHOU
Yin_Shou , Lanzhou Medical College.A voucher specimen(98001)was deposited in the Herbarium of the Pharmacy
Department , Lanzhou Medical College.
2.3　Extraction and isolation
Dried and powdered roots of R.uniflorum (3 kg)
were exhaustively extracted with MeOH at room tempera-
ture , and the mixed extract concentrated under reduced
pressure.The residue was suspended in water and sub-
jected to sequential extraction with petrol , EtOAc and
n_BuOH , successively.The n_BuOH extract(40 g)was
chromatographed over a silica gel column (200-300
mesh , 500 g) and eluted with CHCl3 in increasing
amounts of MeOH.The fractions were combined by TLC
Received:2001-07-16　Accepted:2001-09-17
Supported by the National Natural Science Foundation of China(29772010).
＊Author for correspondence.E_mail:.
植　物　学　报　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　
Acta Botanica Sinica　2002 , 44(3):359-361
Table 1 　 1H and 13C-NMR spectral data of compound 3 (400
MHz , C5D5N)
No. H C Observed connectivities
in HMBC spect rum
1 0.97 m , 1.81 m 38.29 t H_2, H_25
2 1.91 m , 2.20 m 26.54 t H_1
3 3.35 dd(11.8 , 4.1) 88.56 d H_1, H_2 , Ara_1′, H_23 ,H_24
4 39.64 s H_23 , H_24
5 55.32 d H_24 , H_23 , H_1
6 26.61 t H_26
7 32.82 t H_26
8 40.86 s H_11 ,H_18 , H_6 ,H_26 ,H_27
9 135.49 s H_11 , H_12 , H_18, H_27
10 36.65 s H_1, H_2 , H_25
11 5.70 d(10.6) 127.34 d H_18
12 6.49 d(10.6) 125.99 d H_18
13 138.25 s H_12 , H_26 , H_27
14 42.48 s H_12 , H_15 , H_26, H_27
15 1.67 m , 2.15 m 32.00 t H_26 , H_27 , H_16
16 1.65 m , 2.01 m 25.68 t H_15 , H_27
17 47.16 s H_22
18 1.97 54.67 d H_12
19 27.80 d H_29 , H_21 , H_22
20 2.81 m 34.67 d H_19 , H_29 , H_30
21 32.60 t H_30
22 24.99 t H_20 , H_29
23 1.26 s 27.90 q H_3, H_24
24 0.92 s 16.66 q H_3, H_23
25 0.86 s 18.37 q H_1
26 1.14 s 17.00 q
27 1.00 s 21.23 q H_26
28 176.58 s Glc_1″, H_22 , H_21
29 0.75 d(6.5) 19.46 q H_28
30 0.97 d(6.5) 16.42 q
Ara_3
1′ 4.75 d(7.0) 107.47 d
2′ 4.45 m 72.88 d
3′ 4.16 m 74.58 d
4′ 4.32 m 69.47 d
5′ 4.02 m , 3.98 m 66.70 t
Glc_28
1″ 6.20 d(8.1) 96.37 d
2″ 4.17 m 74.09 d
3″ 4.42 m 79.25 d
4″ 4.37 m 71.25 d
5″ 3.83 m 78.81 d
6″ 4.28 m , 4.24 m 62.36 t
monitors.The fractions were submitted to silica gel
column to afford compound 1 (50 mg), 2 (42 mg), 3(56 mg), 4(45 mg), 5(80 mg)and 6(46 mg).
2.4　Identification
Ziyu glycoside Ⅱ(1)　White powder , mp 243-
245 ℃.FABMS m/ z:627 [ M +Na] + , 605 [ M +
H ] + , 455 , 437 , 410 , 391. EIMS m/ z:454
[M-Ara-H2O] + , 409 , 264 , 190 , 146.The spectral
data were similar to those of Cheng et al[ 4] .
Fig.1.　Key HMBC correlations of compound 3.
28_O_β_D_glucopyranosyl_pomolic acid ester (2)　White powder , mp 279-280 ℃.FABMS m/ z:657
[M+Na] + , 635 [M +H] + , 472 , 455 , 427.EIMS
m/z:454 [M-Glc-H2O] + , 409 , 264 , 246.Spectral
data were similar to those of Cheng et al[ 4] .
3_O_α_L_arabinopyranosyl_urs_9(11), 12_dien_
28_oic acid β_D_glucopyranosyl ester (3)　Platelet
crystals(MeOH), mp 247-249 ℃.[ α] 20D +21°(pyri-
dine , c 0.12).IR νKBrmax cm-1:3 437 (OH), 1 729(C O), 1 645 (C C), 1 468 , 1 370 , 1 068.UV
λMeOHmax (log ε):280(3.91)nm.FABMS m/ z:771 [M
+Na] + , 749 [M+H] + , 586 [M-Glc] + , 454 [M-
Glc - Ara ] + , 264 , 246 , 201.HRFABMS m/z:
748.439 4 , calcd.748.439 2 for C41H64O12.1H_NMR
and 13C_NMR data , see Table 1.
Rosmutin(4)　White powder , mp 212-213 ℃.
FABMS m/ z:673 [ M+Na] + , 651 [ M+1] +.EIMS
m/z:488 [M -Glc] + , 442 , 370 , 264 , 246 , 218 ,
201 , 187 , 146.The spectral data were similar to those of
Du et al[ 5] .
Ziyu glycoside Ⅰ(5)　White powder , mp 256-
260 ℃.FABMS m/ z:789 [M +Na] + , 455 [M +H-
162-132-H2O] + , 431.Identified by co_IR spectra
with an authentic sample[ 4] .
Sauvissimoside R1 (6)　White needles , mp 275
-279 ℃.FABMS m/z:703 [M +Na] + , 681 [ M+
1] +.The spectral data were similar to those of Qing et
al[ 6] .
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祁州漏芦中一个新的三萜皂甙
张永红1　芦志刚2　李新圃2　汪汉卿1＊
(1.中国科学院兰州化学物理研究所 , 兰州 730000;2.中国农业科学院兰州畜牧与兽药研究所 , 兰州 730050)
摘要:　从祁州漏芦(Rhaponticum uniflorum (L.)DC.)的根中分离得到 6个三萜皂甙(1～ 6),其中化合物 3 为一新的
三萜皂甙 , 命名为 unifloroside , 其结构经 1D , 2D_NMR及化学方法鉴定为 3_O_α_L_arabinopyranosy l_urs_9(11), 12_dien_
28_oic acid β_D_glucopyranosy l ester。
关键词:　祁州漏芦;菊科;三萜皂甙;unifloroside
中图分类号:R914　　　文献标识码:A　　　文章编号:0577-7496(2002)03-0359-03
收稿日期:2001-07-16　接收日期:2001-09-17
基金项目:国家自然科学基金(29772010)。
＊通讯作者。E_mai l:.
(责任编辑:王　葳)
ZHANG Yong_Hong et al:A New Triterpenoid Saponin from Rhaponticum uniflorum (Compositae) 361