全 文 ：坚龙胆中的一个新裂环烯醚萜甙?
许 敏 , 王 东 , 张颖君 ** , 杨崇仁??
(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 )
摘要 : 从坚龙胆 ( Gentiana rigescens) 的根中分离得到 1 个新的裂环烯醚萜甙 , 命名为坚龙胆甙 A ( 1) , 以
及 8 个已知化合物 : 龙胆苦甙 (2) , 6′- O-β-D-吡喃葡萄糖基-龙胆苦甙 (3 ) , 马钱子酸 (4 ) , 6′- O-β-D-吡喃
葡萄糖基-马钱子酸 (5) , 獐牙菜甙 (6) , 2′- (邻 , 间-二羟基苯甲酰基) -獐牙菜甙 (7) , 獐牙菜苦甙 (8 ) , 四
乙酰开联番木鳖甙 (9)。它们的化学结构通过现代波谱解析得以鉴定。化合物 3 , 5 和 9 为首次从坚龙胆中
分离得到。
关键词 : 坚龙胆 ; 裂环烯醚萜甙 ; 坚龙胆甙 A
中图分类号 : Q 946 文献标识码 : A 文章编号 : 0253 - 2700(2006)06 - 669 - 04
A New Secoiridoidal Glucoside from Gentiana
rigescens (Gentianaceae)
XU Min, WANG Dong, ZHANG Ying-Jun* * , YANG Chong-Ren* *
( State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany,
ChineseAcademy of Sciences, Kunming 650204 , China)
Abstract : A new acylated secoiridoidal glucoside, named gentiorigenoside A (1 ) , was isolatedfromthe root of Gentiana
rigescens (Gentianaceae) , together with eight known compounds, gentiopicroside ( 2) , 6′- O-β- D-glucopyranosyl genti-
opicroside (3) , loganic acid (4 ) , 6′- O-β- D-glucopyranosyl loganic acid ( 5) , sweroside ( 6 ) , 2′-( o, m-dihydoxy-
benzyl ) -sweroside (7) , swertiamarin (8) and secologanoside (9) . heir structureswereelucidated on the basis of detailed
spectroscopic analysis . Iridoidal glucosides 3 , 5 and 9 were isolated for the first time from the title plant .
Key words: Gentiana rigescens; Iridoidal glucosides; Gentiorigenoside A
“Long-Dan”is a well-known traditional Chinese
medicinal (TCM) herb commonly used for treatment of
inflammation, hepatitis, rheumatism, cholecystitis
and tuberculosis . In the Chinese Pharmacopoeia, the
roots of four plants from the genus Gentiana ( Genti-
anaceae) , G. scabra, G. manshurica, G. triflora,
and G. rigescens, are used as the raw materials of
“Long-Dan”( Editorial Boardof Chinese Pharmacopoe-
ia, 2005 ) . Among them, the former three species
aremainly distributed in thenortheast of China, while
the later one is mainly growing in the southwest of Chi-
na, particularly in the mountainous areas of Yunnan
province and called as“ Jian-Long-Dan”.
Likemany of the Gentiana plants, previous study
showed that G. rigescens contains rich iridoidal glu-
cosides with gentiopicroside ( 2 ) as major constituents
(Sun and Xia, 1984; Zhang and Tian, 1991 ) . Our
further detailed chemical investigation on this plant led
云 南 植 物 研 究 2006 , 28 (6) : 669～672
Acta Botanica Yunnanica

?
?? ?Author for correspondence . E - mail : zhangyj@ mail .kib. ac. cn, cryang@mail .kib. ac. cn Tel : + 86 - 871 - 5223235
Received date: 2006 - 07 - 20 , Accepted date: 2006 - 09 - 20
作者简介 : 许敏 ( 1976 - ) 女 , 云南人 , 在读博士研究生 , 主要从事中药资源与化学研究。E - mail : xumin@ mail . kib. ac. cn ?
Foundation item: This work was supported by the Opening Foundation of the State Key Laboratory of Phytochemistry and Plant Resources in West
China, Kunming Institute of Botany, the Chinese Academy of Sciences
to the isolation of a new acetylated secoiridoidal glyco-
side, named gentiorigenoside A ( 1 ) , together with
eight known iridoidal glucosides (2 - 9 ) fromthe root .
Their structures were identified by detailed extensive
NMR spectroscopic experiments, including 1 H-1 H CO-
SY , HMBC and HMQC . This paper describes theiso-
lation and structure determination of these compounds .
Furthermore, a possible biogenetic pathway of these
compounds was also proposed .
Results and Discussion
The methanolic extract of the roots of G. rig-
enscens was suspended into water and partitioned suc-
cessively with EtOAc and n-butanol . Repeatedly chro-
matography of the EtOAc, n-butanol and H2 O frac-
tionsonDiaion HP20SS, MCI-gel CHP20P, Chromat-
orex ODS and silicagel column let to the isolation of a
new compound 1 , together with 8 known constituents
(2 - 9) . Theknown compounds wereidentified as gen-
tiopicroside (2) (Liu and Li , 1994) , 6′- O-β- D-glu-
copyranosyl gentiopicroside (3 ) (Mpondo and Chulia,
1988) , loganic acid ( 4) (Calis et al , 1984) , 6′- O-
β-D-glucopyranosyl loganic acid ( 5 ) ( Tomita and
Mouri , 1996) , sweroside (6) (Luo and Nie, 1992 ) ,
2′-( o, m-dihydoxybenzoyl )-sweroside ( 7 ) ( Tan et
al , 1996 ) , swertiamarin ( 8 ) ( Luo and Nie, 1992 )
and secologanoside (9) ( Calis and Sticher, 1984) , re-
spectively, by direct comparison of their spectral data
( including IR , MS, and 1 H and 13 C NMR ) with
those of the literature values . Of them, compound 2
was themajor constituent in the root, and 3 , 5 and 9
were isolated for the first time fromthe title plant .
Compound 1 was obtained as a white amorphous
powder . Its molecular formula was assigned as C22 H30
O12 on the basis of the HR-ESI-MS ( m?z 485 .1354
[M-H ] - , Calcd . 485 .1346 ) and 13 C NMR data .
The
1
H and
13
C NMR dataof 1 were closely related to
thoseof 2 (Liu and Li , 1994 ) , except for theobvious
downfield shift of C - 4 (δ121 .2) , C - 5 (δ136 .3 ) ,
and C - 11 (δ172 .8) , together with the appearanceof
two acetyl groups [δH 2 .05 , 2.07 (each 3H, s) ; δC
20 .8 , 20 .7 and 172 .8 ( ×2) ] and one ethoxyl [δH
4 .10 (2H, q, J = 7 .0 Hz) and 0 .88 (3H, t, J =
7 .0 Hz) ; δC 61 .2 and 14 .4 ] group . These observa-
tions suggested that the six-membered lactone ring in 2
was opened, acetylated and esterified in 1 , which was
further confirmed by the HMBC experiment .
Fig . 1 Important HMBC correlations of 1
In the HMBC spectraof 1 (Fig . 1) , themethyl-
ene (δ4 .10) was correlated with the carbonyl carbon
atδ172 .8 ( C - 11) , indicating that C - 11 was esteri-
fied with an ethyl group . The downfield chemical shift
of C?H - 7 (δC 70 .9 , δH 5 .04 and 5 .00 ) andC?H - 6′
(δC 64 .5 , δH 4 .09 and 4 .40) , together with the HM-
BC correlations of H - 7 and H - 6′with two acetyl car-
bonyl carbon atδ 172 .8 could assign the two acetyl
groups located on C - 7 position of the aglycone and C
- 6′position of the glucopyranosyl unit, respectively .
In addition, other key HMBC correlations ( Fig . 1 )
confirmed the structural of 1 . Thus, the structure of
gentiorigenoside A was determined as shown in 1 ,
which should be a natural product since ethanol was
avoided during all the extraction and isolation proce-
dure .
The isolated compounds could be divided into
three groups, iridoidal glucosides (4 , 5) , secoiridoi-
dal glucosides ( 1 , 9) and secoiridoidal glucosideswith
lactone rings ( 2 - 3 , 6 - 8 ) . A possible biogenetic
pathway of these compounds was proposed as shown in
Fig . 2 . It suggested that compound 4 could be a pre-
cursor of all the other iridoidal glucosides biosynthe-
sized in G. rigescens and compound 2 , themajor con-
stituents in the root, is an important intermediate for
the formation of 3 , 6 , 7 and 8 .
076 云 南 植 物 研 究 28 卷
Experimental
General Experimental Procedures Optical rotations were
measured onaSEPA-3000 automatic digital polarimeter . IR spec-
tra wereconducted on a Bio-Rad FTS-135 spectrometer with KBr
pellets . NMR spectra were measured in CD3 OD and recorded on
aBruker AV-400 (for 1 H NMR and13 C NMR) andDRX-500 (for
2D NMR) instrument with TMS as internal standard . ESI-MS
(negative ionmode) and HR-ESI-MS ( negative ionmode) spectra
were recorded on VGAutoSpe3000 and API Qstar Pulsar LC?TOF
Spectrometers, respectively . Column chromatography ( CC) was
performed on Diaion HP20SS (Mitsubishi Chemical Co .) , MCI-
gel CHP20P (75 - 150μm, Mitsubishi Chemical Co .) , Chromat-
orex ODS (100 - 200 mesh, Fuji Silysia Chemical Co . Ltd .) ,
and silicagel (100 - 200 mesh, Qingdao HaiyangChemical Co .) .
Thin layer chromatography ( TLC) was carried on silica gel G
precoated plates (Qingdao Haiyang Chemical Co .) with CHCl3 -
MeOH-H2 O (7∶3∶0 .5 ) . Spots were detected by spraying with
10% sulfuric acid reagents followed by heating .
Fig . 2 A possible biogenetic pathway of the isolated iridoidal glucosides 1 - 9 in G. rigescens
Plant material The roots of Gentiana rigescens Fr . ex
Hemsl . were collected from Chuxiong, Yunnan, China, and
identified by Prof . Chong-Ren Yang . The voucher specimen
(yang0204100) was deposit in Herbariumof Kunming Institute of
Botany (KIB) , Chinese Academyof Sciences ( CAS) .
Extraction and Isolation The powdered air-dried roots of
G. rigescens (9 .2 kg) wereextractedwithMeOH at roomtempera-
ture . After concentrated to almost dryness under reduced pres-
sure, theMeOH extract ( 1290 g) was suspended into H2 O and
partitioned withEtOAc and n-BuOH, successively . TLC analysis
showed that gentiopicroside ( 2) was the major component which
was existed in all of thethreefractions [ CHCl3∶MeOH∶H2 O (7∶3
1766 期 XU Min et al : A New Secoiridoidal Glucoside from Gentiana rigescens (Gentianaceae)
∶0 .5) , Rf 0 .6] . Thefurther isolation was thenfocusedfirstlyon
this major component and its related compounds .
The H2 O layer was concentrated to a small volume ( 400
ml) and applied to a Diaion HP20SS column eluting with H2 O-
MeOH (1∶0 - 0∶1 ) to give five fractions (A1 -A5 ) . Fractions A1
(11 .5 g) and A2 ( 51 g) was separately subjected to Chromator-
ex ODS and silicagel CC to give 3 (49 mg) , 4 (8 .367 g) and5
(21 mg) from A1 , and 2 (38 .927 g) , 4 ( 10 .768 g) , 8 ( 10
mg) and9 (56 mg) fromA2 , respectively . Fraction A4 (36 g)
was chromatographed over MCI-gel CHP20P and silica gel col-
umns to afford 2 (28.303 g) .
The n-BuOH fraction ( 430 g) was chromatographed on a
Diaion HP20SS column eluting with H2 O-MeOH (1∶0 - 0∶1 ) to
give sevenfractions (B1 -B7 ) . FractionB2 (160 g) was subject-
edto MCI-gel CHP20P, Chromatorex ODS and silica gel CC to
give 2 (85 .146 g) and 4 (43 .254 g) . Fraction B6 (4 . 6 g) was
chromatographed over Chromatorex ODS, silica gel and MCI gel
CHP-20P to give1 (5 mg) , 6 ( 57 mg) , 7 (2 .355 g) .
Repeated CC of EtOAc fraction ( 10 g) on silica gel and
Chromatorex ODS to afford 2 (5 .983 g) , β-sitosterol (186 mg)
and daucosterol ( 78 mg) .
Gentiorigenoside A (1) : White amorphous powder, [α]26D
= - 89 .4°( c= 0 .17 MeOH) ; UVλMeOHmax ( logε) : 203 .8 nm;
IR ( KBr ) : 3441 , 2924 , 2854 , 1712 , 1612 , 1270 , 1077
cm- 1 . HR-ESI-MS: m?z 485 .1354 [M ( C22 H30 O12 ) -H ] - ,
Calcd . 485 .1346 . ESI-MS: m?z 485 ( M - ) , 457 , 419 ,
256; 1 H-NMR ( CD3 OD) : δ 7 .43 ( 1H, s, H - 3 ) , 5 . 73
(1H, ddd, J = 9 .5 , 17 .0 , 4 .3 Hz, H - 8 ) , 5 . 60 ( 1H,
m, H - 6) , 5 .48 (1H , d, J = 3 .2 Hz, H - 1 ) , 5 . 21 (1H,
dd, J = 9 .5 , 1 .2 Hz, H - 10a) , 5. 18 (1H, dd, J = 17 .0 ,
1 .2 Hz, H - 10b) , 5. 04 (1H, br d, J = 16 .7 Hz, H - 7b) ,
5 . 00 (1H , br d, J = 16 .7 Hz, H - 7a) , 4 . 64 (1H, d, J =
7 .9 Hz, H - 1′) , 4 . 40 ( 1H, dd, J = 1.9 , 11 .9 Hz, H -
6b′) , 4 . 10 ( 2H , q, J = 7.0 Hz, CH3 - - 蓡CH 蓡2 -O-) , 4 . 09
(1H , dd, J = 7 .1 , 14 .2 Hz, H - 6a′) , 3 . 55 ( 1H , m, H
- 5′) , 3 .35 ( 1H, dd, J = 4 .3 , 3 .2 Hz, H - 9 ) , 3 . 30 -
3 .35 (2H, m, H - 3′, 4′) , 3 . 15 ( 1H , m, H - 2′) , 2. 05 ,
2 .07 (each 3H , s, - 僳CH 僳3 -C = O) , 0 . 88 (3H, t, J = 7 .0 Hz, ?
CH - ?3 -CH2 -O-) . 13 C-NMR (CD3 OD) : δ172 .8 (×3 , C - 11 ,
2×CH3 - - ?C= O) , 150.5 (C - 3 ) , 136 .3 ( C - 5 ) , 134 .9 (C -
8) , 121 .2 (C - 4) , 118 .6 ( C - 10 ) , 117 .3 ( C - 6 ) , 100 .4
(C - 1′) , 98 .8 (C - 1) , 77 .8 ( C - 3′) , 75 .7 ( C - 5′) , 74 .5
(C - 2′) , 71 .3 (C - 4′) , 70 .9 ( C - 7) , 64 .5 ( C - 6′) , 61 .2
(CH3 - - 竕CH 竕2 -O) , 46 .7 ( C - 9 ) , 20 .8 , 20 .7 ( 竕CH 竕3 -C = O) ,
14 .4 ( - ?CH ?3 -CH2 -O) .
Acknowledgements : We aregrateful to themembers of the An-
alytical Group in State Key Laboratory of Phytochemistry and
Plant Resources in West China, Kunming Institute of Botany,
for the spectral measurements .
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276 云 南 植 物 研 究 28 卷