全 文 ：朝鲜蓟叶中一个新的倍半萜内酯
刘 荣1 ,2 , Hsieh Kun-Lung3 , 刘吉开1
?
(1 中国科学院昆明植物研究所植物化学与西部植物资源持续利用国家重点实验室 , 云南 昆明 650204;
2 中国科学院研究生院 , 北京 100049 ; 3 谢氏生物技术有限公司 , 胡志明 越南 )
摘要 : 从朝鲜蓟 ( Cynara scolymus) 叶中分离得到 2 个倍半萜内酯 , 其中一个是新化合物 , 通过波谱学方
法确定其结构为 3β, 8α, 11α, 13-四羟基-10 (14 ) -愈创木烯-1α, 4β, 5α, 6β氢-6α, 12-内酯 ( 1)。
关键词 : 朝鲜蓟 ; 菊科 ; 倍半萜内酯
中图分类号 : Q 946 文献标识码 : A 文章编号 : 0253 - 2700 (2009) 04 - 383 - 03
A New Sesquiterpene Lactone from the Leaves of
Cynara scolymus (Compositae)
LIU Rong
1 , 2
, Hsieh Kun-Lung
3
, LIU J i-Kai
1 *
(1 State KeyLaboratory of Phytochemistry and Plant Resources in West China, Kunming Instituteof Botany, Chinese Academy
of Sciences, Kunming 650204 , China; 2 Graduate University of ChineseAcademy of Sciences, Beijing 100049 , China;
3 HsiehS Biotech . Co ., Ltd ., Ho Chi Minh City, Vietnam)
Abstract : A new guaiane-type sesquiterpene lactone, named 3β, 8α, 11α, 13-tetrahydroxy-10 (14 )-guaien-1α, 4β, 5α,
6βH-6α, 12-olide (1) , together with a known sesquiterpene lactone, cynarinin A (2) , were isolated from the leaves of
Cynara scolymus (Artichoke) . The structure of 1 was elucidated on the basis of MS, IR , 1D, and 2D NMR .
Key words: Cynara scolymus; Compositae; Sesquiterpene lactone
Cynara scolymus (Artichoke) is a traditional her-
baceous plant belonging to the family Compositae and
originating from Mediterranean area . Today, artichoke
is widely distributed all over the world and its sprout is
edible as vegetable . The leaves of artichoke have been
used as choleretic and diuretic in traditional medicine
(Kirchhoff et al. , 1994 ) . Various chemical constitu-
ents (Wang et al. , 2003; Shimoda et al. , 2003; Zhu
et al. , 2004; Schütz et al. , 2004) including polyphe-
nols such as cynarin, caffeoylquinic acids, chlorogenic
acids, sesquiterpenes, and sesquiterpene glycosides
whichwere found fromartichoke, showpharmacological
activities ( Dranik et al. , 1996; Kraft, 1997; Brown
and Rice-Evans, 1998 ) such as antibacterial , antioxi-
dative, antihyperlipidemic, choleretic, bileexpelling,
and hepatoprotective activities . Therefore, we carried
out a further chemical investigation on the leaves of ar-
tichoke cultivated in Vietnam . A newguaiane-type ses-
quiterpene lactone, 3β, 8α, 11β, 13-tetrahydroxy-10
(14 )-guaien-1α, 4β, 5α, 6βH-6α, 12-olide (1 ) and
a known sesquiterpene lactone, cynarinin A (2) (Li et
al. , 2005) were obtained . This paper reports the iso-
lation and structural elucidation of compound 1 .
Results and Discussion
Compound 1 was obtained as a colorless oil . The
negative-ion FABMS showed a quasi-molecular ion
peak [M-H] - at m?z 297 . The molecular formula,
云 南 植 物 研 究 2009 , 31 (4) : 383～385
Acta Botanica Yunnanica DOI : 10 .3724?SP. J . 1143 .2009.09062
? ?Author for correspondence; E-mail : jkliu@ mail .kib. ac. cn; Tel : + 86 - 871 - 5216327
Received date: 2009 - 03 - 30 , Accepted date: 2009 - 05 - 09
作者简介 : 刘荣 ( 1980 - ) 男 , 在读博士研究生 , 主要从事高等真菌化学研究。
C15 H22 O6 , was established by HRESIMS ( m?z
297 .1336 [M-H] - ; calcd 297 .1338 ) , indicating five
degrees of unsaturation . The IR spectrumof 1 exhibited
absorption at 3418 , 1769 and 1639 cm- 1 ascribable to
hydroxyl , γ-lactone and C = C functional groups . The
1 H NMR spectrum (Table 1 ) displayed one secondary
methyl atδH 1 .21 (3H, d, J = 6 .5 Hz, H - 15) . The
13
C NMR andDEPT spectra (Table 1) revealed 15 car-
bon resonances includingonemethyl , four methylenes,
seven methines and three quaternary carbons . The lac-
tone carbonyl resonances were located atδC 82 .0 (d, C
- 6) , 180 .4 (s, C - 12) , four oxygenated carbon res-
onances were observed atδC 78 .6 ( d, C - 3 ) , 71 .2
(d, C - 8 ) , 79 .4 (s, C - 11) and 64 .3 ( t, C - 13 ) ,
and exocyclic methylene resonances atδC 145 .4 (s, C
- 10) and 114 .7 ( t, C - 14) , respectively .
Table 1 1 H and 13C NMR data of 1 (500 and 125 MHz, resp .)
and 2 ( 400 and 125 MHz, resp .)
No .
1 ?(CD3 OD)
δC δH
2 ( C5 D5 N)
δC δH
1 ?43 .1 2 .85 ( m) 40 ?. 2 3 .50 (m)
2 ?39 .1 2.04 (m) ; 1 ?.69 (m) 43 .7 2.48 (m) ; 2 A.09 (m)
3 ?78 .6 3 .63 ( m) 218 0. 6
4 ?47 .8 1 .77 ( m) 47 ?. 5 2 .33 (m)
5 ?52 .6 1 .96 ( m) 52 ?. 2 2 .18 (m)
6 ?82 .0 4.16 (dd, 10 ?.4, 10.1) 82 .4 4.63 (dd, 10 E.2, 9.8)
7 ?61 .7 2.29 (dd, 10 ?.4, 10.0) 57 .4 3 ?.21 (dd, 10 E.2, 9.8)
8 ?71 .2 4 .04 ( m) 70 ?. 5 4 .84 (m)
9 ?47 .7 2 ?.77 (dd, 12 ?.0, 4.2);
2 ?. 09 ( brd, 12 t.0) 49 ?. 6
3 .13 (m) ;
2 ?.56 ( brd, 11 .4)
10 ?145 .4 145 0. 9
11 ?79 .4 79 .8
12 ?180 .4 179 0. 8
13 ?64 .3
4 ?. 00 ( d, 10 V. 4 ) ;
3 ?. 76 ( d, 10 [. 4 ) 65 .0
5 ?. 03 ( d, 10 . 1) ;
4 ?. 56 (d, 10 .0 )
14 ?114 .7 5.01 (s) ; 4.99 (s) 113 0. 7 4.98 (s) ; 4 5.69 (s)
15 ?18 .9 1 .21 ( d, 6 6. 5) 15 .0 1 .24 (d, 7 `. 1 )
Chemical shift valuesδin ppm, coupling constants J inHz ( in parentheses)
The comparison of the
13
C NMR data of 1 with
those of 2 implied that they shared the same planar
structure except for a hydroxyl at C - 3 in 1 instead of
the ketone carbonyl group at C - 3 in 2 ( Li et al. ,
2005) , causing the upfield shifts of C - 3 fromδC
218 .6 in 2 toδC 78 .6 in 1 . The partial structural unit
C - 1 to C - 9 was deduced from the analysis of the
HSQC and
1
H-
1
H COSY spectraof 1 . The HMBC cor-
relations between the AB system signals at δH 4 .00
(1H, d, J = 10 .4 Hz, Ha - 13) andδH 3 .76 ( 1H,
d, J = 10 .4 Hz, Hb- 13 ) and C - 12 and theoxygen-
ated quaternary carbon signal atδC 79 .4 ( s, C - 11)
confirmed two hydroxyl groups attached to C - 11 and C
- 13 , respectively . The HMBC showed the cross-peaks
of H - 15 [δH 1 .21 ( d, J = 6 .5 Hz) ] to C - 3 , C - 4
and C - 5 , H - 6 [δH 4 .16 ( dd, J = 10 .4 , 10 .1 Hz) ]
toC - 12 (δC 180 .4 ) , H - 14 [δH 5 .01 (s) , 4 . 99
(s) ] to C - 1 , C - 9 and C - 10 , and H - 9 [δH 2 .77
( dd, J = 12 .0 , 4 .2 Hz) , 2 . 09 ( brd, J = 12 .0 Hz) ]
to C - 1 , C - 10 and C - 14 , respectively . These infor-
mation confirmed theplanar structureof 1 . The relative
configuration of 1 was determined by comparison with 2
and confirmed by a ROESY experiment . The ROESY
correlations (Fig. 2) of Hα - 1 with H - 3 , and Hα - 5
with H - 3 , H - 7 and Me - 15 indicated that H - 3 , H
- 7 and Me- 15 possessedα-orientations, respectively .
The ROESY correlations of H - 6 with Hβ - 4 and H - 8
suggested that H - 6 and H - 8 possessedβ-orientations,
respectively . On the basis of the evidence mentioned
above, the structure of 1 was elucidated as 3β, 8α,
11α, 13-tetrahydroxy-10 ( 14 )-guaien-1α, 4β, 5α,
6βH-6α, 12-olide .
Fig . 1 The structures of compounds 1 and 2
Experimental
General experimental procedures Fractions were moni-
tored by TLC, and spots were visualized by heating silica gel
plates sprayed with10% H2 SO4 in ethanol . Silicagel (200 - 300
mesh, Qingdao Marine Chemical Inc . , China) and Sephadex
LH-20 (Amersham Biosciences, Sweden) were used for column
chromatography . Optical rotation was measured on a Horbia SE-
PA-300 polarimeter . IR spectrumwas obtained on aBruker Ten-
sor 27 instrument with KBr pellets . NMR spectra were recorded
on Bruker AM-400 and Bruker DRX-500 spectrometers in
CD3 OD withTMS as an internal standard . FAB-MS was takenon
483 云 南 植 物 研 究 31 卷
Fig . 2 Key HMBC and ROESY correlations of compounds 1
a VG Auto Spec-3000 spectrometer, and HRESI-MS was record-
ed with an API QSTAR Pulsar 1 spectrometer .
Plant material Theleaves of Cynarascolymuswerecollected
fromHo Chi Minh City, Vietnam, in February, 2007 . The voucher
specimen ( 20070208-Tony-01 ) was deposited in the Herbarium of
KunmingInstitute of Botany, Chinese Academy of Sciences (CAS) .
Extraction and isolation The dried leaves of Artichoke
( Cynara scolymus) (5 kg) weremashed and extractedwith 75%
ethanol at roomtemperaturefor 3×48 h . The extractswerecom-
bined and concentrated to dryness under reduced pressuretogive
the residue ( 380 g) , which was suspended in H2 O and parti-
tioned sequentially with petroleumether, EtOAc, and n-BuOH .
TheEtOAc extract ( 50 g) was separated into eleven fractions
(F1 -F11 ) by silica gel column chromatography using a CHCl3?
MeOH gradient . Thefraction F9 (100 mg) was further subjected
to Sephadex LH-20 column chromatography using CHCl3?MeOH
(1∶1 , v?v) as eluent, and repeated silicagel columnchromatog-
raphy eluted with chlroform?acetone form10∶1 ( v?v) to 4∶1 ( v?
v) to afforded the compounds 1 (20 mg) and 2 (7 mg) .
3β, 8α, 11α, 13-Tetrahydroxy-10 ( 14 )-guaien-1α,
4β, 5α, 6βH-6α, 12-olide ( 1 ) C15 H22 O6 , colorless oil .
[α]23D + 32 .1°( c= 0 .78 , MeOH ) . IRνKBrmax cm- 1 : 3418 , 2928 ,
1769 , 1639 , 1139 , 1071 , 980 . 1 H and13 C NMR: seeTable1 .
Negative FABMS m?z 297 [M-H] - ; HRESIMS m?z 297 .1336
[M-H] - ( calcd for C15 H21 O6 297 .1338) .
Cynarinin A ( 2 ) C15 H20 O6 , white power . [α]22D +
90 .5°( c= 1 .59 , MeOH) . IRνKBrmax cm- 1 : 3479 , 3423 , 1771 ,
1749 , 1134 , 977 . 1 H and 13 C NMR: seeTable 1 .
Acknowledgement: This project was supported by HsiehS Bio-
tech . Co ., Ltd . .
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5834 期 LIU Rong et al. : A New SesquiterpeneLactone fromthe Leaves ofCynara scolymus (Compositae)