全 文 ：A New C_Glycosylflavone from the Leaves of Cycas panzhihuaensis
ZHOU Yan , PENG Shu_Lin , LI Chao_Luan , WANG Ming_Kui , DING Li_Sheng＊
(Chengdu Institute of Biology , The Chinese Academy of Sciences , Chengdu 610041 , China)
Abstract:　A new C_glycosylflavone , named panzhihuacycaside (1), was isolated from the leaves of Cycas
panzhihuaensis L.Zhou et S.Y.Yang (Cycadaceae)along with 2 ,3_dihydrohinokiflavone (2), 5 ,5″, 7 ,7″,
4′,4 _hexahydroxy_(2′,8″)_biflavone (3), vanillic acid (4), β_sitosterol(5)and daucosterol (6).Their
structures were elucidated by spectral and chemical evidence.
Key words:　Cycas panzhihuaensis;C_glycosylflavone;panzhihuacycaside
　　There are 14 species of Cycas genus(Cycadaceae)
in China
[ 1] .C.panzhihuaensis L.Zhou et S.Y.Yang ,
an endemic species of Cycas , grows abundantly in the
southwest of China.The chemical constituents of the
stems , flowers and seeds of this plant were recently inves-
tigated in our laboratory
[ 2] .During our continuous investi-
gation , a new C_glycosylflavone named panzhihuacycaside(1), together with five known compounds , was obtained
from the leaves of C.panzhihuaensis.
1　Results and Discussion
Panzhihuacycaside (1)was obtained as yellow nee-
dles , showing positive color reaction with the Mg_HCl
test.The UV spectrum had maximum absorptions at 269
and 337 nm and IR had absorptions at 3 410 , 1 660 ,
1 610 , 1 580 , 1 520 , 1 440 cm-1 , suggesting that 1
was a flavonoid glycoside
[ 3] .On the basis of HR_
FABMS , the molecular formula of 1 was assigned as
C39H50O24.
Upon acid hydrolysis , 1 yielded 1a , which was des-
ignated as apigenin_8_C_β_D_glucopyranoside based on
the
13
C_NMR spectrum[ 4] , and a glucose , a galactose and
a rhamnose were detected by PC and TLC in the aqueous
fraction after removal of 1a.
Partial acid hydrolysis of 1 afforded 1b.By compar-
ison of its
13
C_NMR with that of 1a , 1b showed a set of
additional signals of sugar moiety concluded by a galacto-
syl and a rhamnosyl unit , which was deduced to be at-
tached to the hydroxyl group at C_6″(δC 69.9)of 1a.
The negative ion FABMS spectrum of 1b gave an [ M-
H] - ion peak at m z 739 and fragment ion peaks at m z
577 [M-gal] - and 430 [M-(gal-rha)-H] - , indi-
cating that the terminal sugar is galactose , and the central
one is rhamnose.The EIMS spectrum of its acetate exhib-
ited the fragment ion at m z 331 , which further confirmed
the terminal sugar of 1b to be galactose.Thus , the at-
tachment sequence of sugar moiety of 1b was determined
as _glucose_rhamnose_galactose. Comparison of the
13
C_NMR spectrum of 1with that of 1b , it was shown that
there is an additional terminal glucosyl unit.
The HMQC experiment of 1 revealed correlations of
the four sugar residues , δC 73.3 δH 2.97(d , J =7.5
Hz), δC 104.5 δH 4.39 (d , J =7 Hz), δC 104.2 δH
4.21 (d , J =7 Hz), δC 100.9 δH 4.92 (s),
respectively.Evaluation of coupling constants of anomeric
protons allowed the identification of two β_glucopyranose ,
one β_galactose and oneα_rhamnose units.
The linkage of the sugar moieties was deduced from
the HMBC experiment(Fig.1).The HMBC spectrum of
1 exhibited correlation peaks between H_1″(δ2.97)of
the inner glucose and C_8(δ104.3)of the aglycone , be-
tween H_1 (δ4.92)of the central rhamnose and C_6″(δ69.8)of the inner glucose.Moreover , there were also
correlations between H_1″″(δ4.21)of the terminal ga-
lactose and C_2 (δ76.8)of the central rhamnose , as
well as between H_1″″′(δ4.39)of the terminal glucose
and C_4 (δ82.4)of the central rhamnose.
Therefore , the structure of 1 was determined as api-
genin_8_C_β_D_galacopyranosyl(1 ※2)_[ β_D_glucopyr-
anosyl(1※4)]_α_L_rhamnopyranosyl (1 ※6)_β_D_glu-
coside.
Based on comparison with the authentic samples or
with
13
C_NMR data and with physicochemical data , com-
pounds 2-6 were identified as 2 ,3_dihydrohinokiflavone
Received:2000-08-25　Accepted:2000-09-08
Supported by the Special Project of Biological Science and Technology of the Chinese Academy of Sciences(STZ_97_3_08).
＊Author for correspondence.
植　物　学　报　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　
Acta Botanica Sinica　2002 , 44(1):101-103
Fig.1.　Key HMBC correlations(from H to C)for compound 1.
Table 1　1H and 13C_NMR spectral data of compounds 1 , 1a and 1b
C , H atom 1 1a 1b 1 HMBC(H to C)
Aglycone moiety
2 163.9(s) 163.9(s) 163.7
3 102.6(d) 101.8(d) 102.4 6.78(s) C:2 , 4 ,1′
4 182.0(s) 181.9(s) 181.9
5 160.8(s) 160.2(s) 160.6
6 98.2(d) 97.9(d) 98.2 6.28(s) C:5 , 7
7 162.2(s) 162.6(s) 162.2
8 104.3(s) 104.1(s) 104.1
9 155.8(s) 155.8(s) 155.6
10 103.2(s) 102.9(s) 103.0
1′ 121.6(s) 121.3(s) 121.4
2′, 6′ 128.8(d) 128.5(d) 128.6 7.97(d , J =8 Hz) C:1′
3′, 5′ 116.0(d) 115.7(d) 115.8 6.95(d , J =8 Hz) C:4′
4′ 161.2(s) 161.2(s) 161.2
Sugar moiety
glc 1″ 73.3(d) 73.1(d) 73.1 2.97(d , J=7.5Hz) C:8 , 2″
2″ 70.8(d) 70.6(d) 70.6 3.40 C:1″, 4″
3″ 79.4(d) 78.3(d) 79.5 3.041)
4″ 70.4(d) 70.3(d) 70.4 3.69 C:2″, 6″
5″ 80.1(d) 81.6(d) 80.1 3.48
6″ 69.8(t) 60.9(t) 69.9 3.041) C:5″, 1
rha 1 100.9(d) 100.1 4.92(s) C:6″, 2
2 76.8(d) 76.7 4.02 C:1″″, 1 , 3
3 69.9(d) 70.1 3.581)
4 82.4(d) 71.3 3.15 C:1″′, 5
5 66.7(d) 68.1 2.35 C:4 , 6
6 17.6(q) 17.6 0.57(d , J =6 Hz)
gal 1″″ 104.2(d) 104.1 4.21(d , J =7 Hz) C:2 , 2″″
2″″ 71.6(d) 71.5 3.78 C:1″
3″″ 74.2(d) 74.8 2.99 C:1″″, 5″″
4″″ 69.2(d) 69.1 4.19
5″″ 76.8(d) 76.6 3.041) C:4″
6″″ 60.9(t) 60.7 3.581)
glc 1″′ 104.5(d) 4.39(d , J =7 Hz) C:4 , 2″″′, 3″′
2″′ 74.2(d) 2.97 C:1″′, 3″″′
3″′ 76.8(d) 3.06 C:4″″′
4″′ 70.1(d) 3.581) C:5″″′
5″′ 76.4(d) 3.041)
6″′ 61.1(t) 3.48
For compound 1 13C 100MHz , 1H 400MHz.For compounds 1a and 1b , 13C 75MHz , 1H 300 MHz.All assignment of compound 1 i s based on 2D-NMR(1H_
1H COSY , HMQC, HMBC).1)Signal patterns are unclear due to overlapping.
(2)[ 5] , 5 ,5″,7 ,7″,4′,4 _hexahydroxy_(2′,8″)_biflavone
(3)[ 2] , vanillic acid(4)[ 6] , β_sitosterol(5)[ 7] and dau-
costerol(6)[ 7] respectively.
2　Experimental
2.1　General experimental procedures
Optical rotation was recorded with a Perkin_Elmer
241 polarimeter using DMSO as solvent.UV spectrum was
recorded using Cintra 20 UV_Visible spectrometer.IR
spectrum was measured on a Nicolet MX_1 as a pressed
KBr disk.NMR spectra were recorded using UNITY
INOVA_400 and Bruker AP_300 instruments in DMSO_d6
with TMS as the internal standard.Mass spectra were
measured on a VG AutoSpec_3000 mass spectrometer.
102　 植物学报　Acta Botanica Sinica　Vol.44　No.1　2002
2.2　Plant material
The leaves of Cycas panzhihuaensis L.Zhou et S.
Y.Yang were collected in Panzhihua Municipality , Si-
chuan Province of China in May 1997 , and identified by
Prof.LI Chao_Luan.The voucher specimen was deposited
in the herbarium of Chengdu Institute of Biology , the Chi-
nese Academy of Sciences , China.
2.3　Extraction and isolation
The dried and finely powdered leaves (7.5 kg)of
Cycas panzhihuaensis were extracted three times with
MeOH at room temperature.After removal of the solvent ,
the residue was dissolved in water and successively frac-
tionated with petroleum ether (bp 60-90 ℃), EtOAc
and n_BuOH.The water phase was then treated on resin
D101 to give brown substance(2 g), which was applied
to column chromatography on silica gel eluting with
CHCl3_MeOH_H2O (40∶10∶1 , 50 mL fraction)to yield
compound 1 (48 mg).The EtOAc extract (23 g)was
subjected to repeated silica gel CC eluting with petroleum
ether acetone and CHCl3 MeOH H2O to give compound 2
(258 mg), 3 (38 mg), 4(15 mg), 5 (45 mg)and 6(33 mg).
2.4　Identification
Panzhihuacycaside(1)　Yellow needles , mp 215
-216 ℃, [α] 20D -64.04°(c 1.14 , DMSO).UV λDMSOmax
nm:269 , 337;IR νKBrmax cm-1:3 410 (OH), 1 660
(C O), 1 610 , 1 580 , 1 520 , 1 440 (Ar_H).HR_
FABMS m z:903.269 3 (C39H51O24 , cal:903.277 0
[M+H] +).1H and 13C_NMR data were shown in Table
1.
Acid hydrolysis of compound 1　Compound 1(20
mg)was heated in 15%HCl at 90 ℃for 8 h.After neu-
tralization with 5% KOH , the reaction mixture was ex-
tracted with n_BuOH.The extract was chromatographed
on silica gel column eluting with CHCl3_MeOH_H2O(50∶
10∶1)to afford 1a (7 mg).13 C_NMR data of 1a are
shown in Table 1.In the aqueous phase glucose , galac-
tose and rhamnose were detected by PC and TLC.
Partial acid hydrolysis of compound 1 　Com-
pound 1(15 mg)was heated in 5%HCl at 90 ℃ for 2
h.After neutralization with 5%KOH , the reaction mix-
ture was extracted with n_BuOH.The extract was chrom-
atographed on silica gel column eluting with CHCl3_
MeOH_H2O(30∶10∶1)to afford 1b (8 mg).FAB_MS
(negative ion)m z:739 [M-H] - , 577 [M-gal] - ,
430 [M-gal-rha-H] -.1H_NMR and 13C_NMR data
are shown in Table 1.In the aqueous phase glucose was
detected by PC and TLC.　　Acetylation of 1b 　1b (5 mg)was treated with
acetic anhydride (1 mL)and pyridine (1 mL)at room
temperature for 24 h and the acetylate was purified on a
silica gel column eluting with CHCl3_MeOH_H2O (30∶10
∶1)to yield acetylate of 1b.EI_MS m z:331 [ gal
(Ac)4 ] +.
References:[ 1] 　Guan Z_T(管中天), Zhou L(周林).Cycads of China.
Chengdu:Sichuan Science and Technology Press , 1996.(in Chinese)[ 2] 　Zhuo Y(周燕), Zhang X_R(张晓王容), Jiang S_Y(蒋舜
媛), Li C_L(李朝銮), Peng S_L(彭树林).Chemical
constituents of Cycas panzhihuaensis.Chin J Appl Environ
Biol(应用与环境生物学报), 1999 , 5:367-370.(in
Chinese with English abstract)[ 3] 　Laboratory of Phytochemistry , Shanghai Institute of Materia
Medica , The Chinese Academy of Sciences (中国科学院
上海药物研究所植物化学研究室).Handbook for Iden-
tification of Flavonoids.Beijing:Science Press , 1982.(in
Chinese)[ 4] 　Agrawal P K.Carbon_13 NMR of Flavonoids.New York:
Elsevier , 1989.283-364.
[ 5 ] 　Markham K R , Sheppard C , Geiger H.13C-NMR studies of
some naturally occurring amentoflavone and hinokiflavone
biflavonoids.Phytochemistry , 1987 , 26:3335-3337.
[ 6] 　Sadtler Research Laboratories.Sadtler Standard Carbon_13
NMR Spectra.1976.1211c.[ 7] 　Wang J_R(王俊儒), Peng S_L(彭树林), Wang M_K(王
明奎), Feng J_T(冯俊涛), Ding L_S(丁立生).Chemi-
cal constituents of the Anemone tomentosa root.Acta Bot Sin(植物学报), 1999 , 41:107-110.(in Chinese with En-
glish abstract)
攀枝花苏铁叶中的一个新黄酮碳甙
周　燕　彭树林　李朝銮 　王明奎　丁立生＊
(中国科学院成都生物研究所 , 成都 610041)
摘要:　从攀枝花苏铁(Cycas panzhihuaensis L.Zhou et S.Y.Yang)叶中分离出 6 个化合物 , 其中 1个为新黄酮碳甙 ,
命名为攀枝花苏铁甙(1),其结构通过波谱解析和化学降解得以确定。 其余化合物分别鉴定为 2 , 3_二氢偏柏黄酮
(2)、 5 , 5″, 7 , 7″, 4′, 4 _六羟基_(2′, 8″)_双黄酮(3)、香草酸(4)、β_谷甾醇(5)和胡萝卜甙(6)。
关键词:　攀枝花苏铁;黄酮碳甙;攀枝花苏铁甙
中图分类号:R914　　　文献标识码:A　　　文章编号:0577-7496(2002)01-0101-03
收稿日期:2000-08-25　接收日期:2000-09-08
基金项目:中国科学院生物科学与技术特别支持项目(STZ_97_3_08)。
＊通讯作者。
(责任编辑:王　葳)
ZHOU Yan et al:A New C_Glycosylflavone from the Leaves of Cycas panzhihuaensis 103