Two glycosides from the stem bark of Tetracentron sinense

Article abstract of DOI:10.1016/S0031-9422(99)00457-4

Two glycosides, tetracentronsides A and B, were isolated from the stem bark of Tetracentron sinense Oliv., along with ten known compounds, β- sitosterol, lupeol, betulinic acid, oleanolic acid, vanillic aldehyde, vanillic acid, maslinic acid, huazhongilexin, daucosterol and catechin. On the basis of spectral and chemical evidence, tetracentronside A and B were identified as 3,4,5-trimethoxyphenyl-O-6'-O-vanilloyl-β-D-glucopyranoside and (8R, 8'R) 9-β-D-glucopyranosyl dihydrocubebin, respectively. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0031-9422(99)00457-4

Phytochemistry 53 (2000) 1001±1003
www.elsevier.com/locate/phytochem
Two glycosides from the stem bark of Tetracentron sinense
Jin-hai Yia, Guo-lin Zhangb, Bo-gang Lib, Yao-zu Chena,*
aThe Chemistry Department of Zhejiang University, Hangzhou 310027, People's Republic of China
bChengdu Institute of Biology, Academia Sinica, Chengdu 610041, People's Republic of China
Received in revised form 28 June 1999
Abstract
Two glycosides, tetracentronsides A and B, were isolated from the stem bark of Tetracentron sinense Oliv., along with ten
known compounds, b-sitosterol, lupeol, betulinic acid, oleanolic acid, vanillic aldehyde, vanillic acid, maslinic acid,
huazhongilexin, daucosterol and catechin. On the basis of spectral and chemical evidence, tetracentronside A and B were
identi®ed as 3,4,5-trimethoxyphenyl-O-6'-O-vanilloyl-b-D-glucopyranoside and (8R, 8'R) 9-b-D-glucopyranosyl dihydrocubebin,
respectively. 7 2000 Elsevier Science Ltd. All rights reserved.
Keywords: Tetracentron sinense; Magnoliaceae; Tetracentronside A; Tetracentronside B
1. Introduction
The IR spectrum suggested the presence of hydroxyl
1
groups (br, 3364 cm 1), carbonyl groups (1732 cm
)
Tetracentron sinense Oliv. is the only representative
of the genus Tetracentron (Magnoliaceae) (How, Wu,
Ko & Chen, 1982). The chemical constituents of this
plant have never been reported. In this investigation,
two new compounds, named tetracentronsides A (1)
and B (2), as well as ten known compounds, b-sitos-
terol (3), lupeol (4), betulinic acid (5), oleanolic acid
(6), vanillic aldehyde (7), vanillic acid (8), maslinic acid
(9), huazhongilexin (10), daucosterol (11) and catechin
(12) were isolated from the stem bark of T. sinense
and characterized by spectral and chemical methods.
and aromatic rings (1612, 1520 cm 1). After hydrolysis
of 1 in 10% methanolic HCl solution, D-glucose and
vanillic acid were detected by co-TLC with authentic
samples.
The b-D-glucopyranosyl moiety of 1 was recognized
1
from a H-NMR signal at d 4.86 (d, J = 7.5 Hz, H-1')
and the evidence mentioned above. The vanilloyl moi-
ety was identi®ed by the mass spectral fragments at m/
z 329 [M-vanilloyl]+ and 151 [vanilloyl]+, and by com-
paring its H- and 13C-NMR spectral data with those
1
of vanillic acid (8). The presence of a trimethoxyphenyl
moiety was inferred based on the above data and
further supported by the mass spectral fragments at m/
z 313 [M-C9H11O4]+ and 184 [C9H11O4 + H]+. In the
HMBC experiment of 1, cross peaks were observed
between H-1' and C-1, and H-6' and %$C1O. (Fig. 1).
Therefore, 1 was determined to be 3,4,5-trimethoxy-
phenyl-O-6'-O-vanilloyl-b-D-glucopyranoside.
Tetracentronside B (2) was obtained as white plates,
and had the molecular formula C26H32O11 as deter-
mined by HR-EIMS (m/z 520.1994). The UV spectrum
showed lmax at 287 and 234 nm. Hydrolysis of 2 in
7% methanolic HCl solution yielded D-glucose, as
detected by co-TLC, in addition to ( )dehydroxycube-
2. Results and discussion
Tetracentronside A (1), isolated as white needles,
had the molecular formula C23H28O12 as shown by
HR-EIMS (m/z 496.1578). It gave a positive colour-
ation with ferric chloride and Molish reagent, indicat-
ing that 1 is a glycoside with phenolic hydroxy groups.
The UV spectrum showed lmax at 271 and 239 nm.
* Corresponding author.
0031-9422/00/$ - see front matter 7 2000 Elsevier Science Ltd. All rights reserved.
PII: S0031-9422(99)00457-4

1002
J. Yi et al. / Phytochemistry 53 (2000) 1001±1003
bin (2a) and ( )dihydrocubebin (2b), obtained by CC
and whose mp, ‰a]D and spectral data were identical to
those reported (Carvalho, Yoshida, Gottlieb & Got-
tlieb, 1987; Anjaneyulu, Atcuta, Ramachandra & Ven-
kateshwarlu, 1981; Koul, Taneija, Pushpangadan &
Dhar, 1988). The b-D-glucopyranosyl moiety of 2 was
500 MHz for 1H and 125 MHz for 13C, TMS as in-
ternal standard; CC: silica gel, 200±300 mesh. Optical
rotations were measured on a PE-241 Polarimeter.
TLC was carried out on silica gel (10±40 m) plates.
Spots were detected by spraying with 5% ethanolic
phosphomolybdic acid solution followed by heating.
1
recognized from the H-NMR signal at d 4.17 (d, J =
7.8 Hz, H-10) and the mass spectral fragment at m/z
358 [M-Glc]+ in the EIMS. The aglycone, a dihydro-
cubebin moiety, was identi®ed by comparing its 1H-
and 13C-NMR spectral with those of 2b, and based on
the evidence mentioned above. Thus, 2 was determined
to be (8R, 8'R ) 9-b-D-glucopyranosyl dihydrocubebin.
3.2. Plant material
Stem bark of T. sinense Oliv. was collected at Nan-
chuan, Chongqing, China, in August 1995 and ident-
i®ed by Prof. G. M. Shu (Sichuan Institute of Chinese
Materia Medica), where a voucher specimen is kept.
3.3. Extraction and separation
3. Experimental
The dried and powdered bark (2 kg) was extracted
with 95% EtOH (8 l  3). After removing solvent
under reduced pressure, 98 g of residue was obtained.
This was divided into six frs. by CC with CHCl3±
MeOH (10 : 0±3). Fr. 1 was subjected to further CC
eluted with a gradient of petroleum ether (bp 60±
908C): EtOAc (10 : 1±3) to yield 3 (98 mg), 4 (16 mg),
5 (45 mg), 6 (20 mg) and 7 (8 mg). From fr. 2, 8 (10
3.1. General
Mps: uncorr. UV: in MeOH; IR: KBr discs; NMR:
mg) and 9 (22 mg) were obtained by CC (CHCl3
:
EtOAc : MeOH, 10 : 10 : 2). 10 was obtained by
recrystallization of fr. 3 from EtOAc. Fr. 4 was separ-
ated by CC (CHCl3 : MeOH, 10 : 1) to yield 11 (80
mg), 1 (25 mg) and 2 (580 mg). 12 (32 mg) was iso-
lated by puri®cation of fr. 6 by CC (CHCl3 : MeOH :
H2O, 13 : 5 : 2 lower layer).
3.4. Identi®cation of known compounds
Compounds 3, 4 (Sholichin, Yamasaki, Kasai &
Tanaka, 1980), 5 (Sholichin et al., 1980), 6, 7, 8
(Wang, Zhang & Chen, 1991), 9 (Kojima & Ogura,
1986), 10 (Lin, Qin & Xu, 1995), 11, and 12 (Porter,
Newman, Foo, Wong & Hemingway, 1982; Yu, Shen,
Shen, Chen & Xiao, 1989) were identi®ed by co-TLC
with authentic samples and by comparison of their
spectral data with those reported.
3.5. Tetracentronside A (1)
25
D
White needles. mp 125±1268C. ‰aŠ
ˆ
43:68 (c =
1
0.234, MeOH). UV lmax (nm): 271, 239; IR nmax cm
3364 (OH), 1732 (C1O), 1612, 1520 (aromatic rings),
1462, 1369, 1215, 1119, 1042, 833, 664. H-NMR spec-
:
1
tral data (CD3OD): d 6.39 (2H, s, 2/6-H), 3.65 (6H, s,
3/5-OMe), 3.67 (3H, s, 4-OMe), 4.87 (1H, d, J = 7.5
Hz, 1'-H), 4.72 (1H, dd, J = 12/2 Hz, 6'a-H), 4.38
(1H, dd, J = 12/7 Hz, 6'û-H), 7.52 (1H, d, J = 1 Hz,
20-H), 6.83 (1H, d, J = 8 Hz, 50-H), 7.53 (1H, dd, J
= 8/1 Hz, 60-H), 3.84 (3H, s, 30-OMe). 13C-NMR
spectral data (CD3OD): d 155.7 (1-C), 96.8 (2/6-C),
Fig. 1. Structures of 1, 2, 2a and 2b (HMBC correlations).

J. Yi et al. / Phytochemistry 53 (2000) 1001±1003
1003
154.8 (3/5-C), 135.0 (4-C), 58.6 (3/5-OMe), 61.2 (4-
OMe), 103.1 (1'-C), 74.9 (2'-C), 77.8 (3'-C), 72.0 (4'-
C), 75.8 (5'-C), 65.3 (6'-C), 122.5 (10-C), 113.9 (20-C),
148.8 (30-C), 153.1 (40-C), 116.0 (50-C), 125.2 (60-C),
167.9 (C1O), 58.5 (30-OMe). FABMS (m/z ): 497 [M
+ 1]+, 329 [M-vanilloyl]+, 313, 295, 184, 169, 151.
HR-EIMS (m/z): 496.1578 (M+, C23H28O12, calc.
496.1581).
(40-C), 78.8 (50-C), 63.3 (60-C). HR-EIMS (m/z):
520.1994 (M+, C26H32O11, calc. 520.1945), 358 [M-
Glc]+, 340, 217, 204, 192, 161, 135.
3.8. Hydrolysis of tetracentronside B (2)
A solution of tetracentronside B (80 mg) in 7%
HCl±MeOH (8 ml) and CH2Cl2 (2 ml) was re¯uxed at
608C for 10 h. The reaction mixture was subjected to
CC (CHCl3 : MeOH, 10 : 0.3) to yield ( )dehydroxy-
cubebin (2a) and ( )dihydrocubebin (2b), whose mp,
‰a]D and other spectral data were identical to those
reported (Anjaneyulu et al., 1981; Carvalho et al.,
1987; Koul et al., 1988).
3.6. Hydrolysis of tetracentronside A (1)
Tetracentronside A (10 mg) was dissolved in 10%
HCl±MeOH solution and heated at 808C for 2 h. In
the reaction mixture, vanillic acid was identi®ed by
TLC on silca gel 60F254 (CHCl3 : MeOH, 10 : 0.3);
glucose was detected on silica gel G [lower phase of
CHCl3 : MeOH : H2O, 15 : 6 : 2-HOAc (9 : 1)].
References
3.7. Tetrecentronside B (2)
Anjaneyulu, A. S. R., Atchuta, R. P., Ramachandra, R. L., &
Venkateswarlu, R. (1981). Tetrahedron, 37, 3641.
25
D
Carvalho, M. G., Yoshida, M., Gottlieb, O. R., & Gottlieb, H. E.
(1987). Phytochemistry, 26, 265.
White plates, mp 156±1578C, ‰aŠ
ˆ
12:18 (c =
1
0.280, MeOH). UV lmax (nm): 287, 234. IR nmax cm
:
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3460, 3348 (OH), 1501, 1447, 1393, 1254, 1038, 926,
810, 700. 1H-NMR spectral data (CD3OD): d 6.61
(2H, d, J < 1.0 Hz, 2/2'-H), 6.66 (2H, d, J = 7.8 Hz,
5/5'-H), 6.59 (2H, dd, J = 7.8/ < 1.0 Hz, 6/6'-H),
2.50±2.70 (4H, m, 7/7'-H), 2.05 (1H, m, 8-H), 1.89
(1H, m, 8'-H), 3.87 (2H, m, 9a/9'a-H), 3.50±3.70 (2H,
m, 9û/9'û-H), 5.87 (4H, s, O2CH2 Â 2), 4.17 (1H, d, J
= 7.8 Hz, 10-H). 13C-NMR spectral data (CD3OD): d
137.1 (1/1'-C), 109.6 (2/2'-C), 149.7 (3/3'-C), 147.9 (4/
4'-C), 111.2 (5/5'-C), 123.9 (6/6'-C), 36.4 (7/7'-C), 45.1
(8-C), 42.6 (8'-C), 71.1 (9-C), 63.6 (9'-C), 102.8
(O2CH2), 105.4 (10-C), 72.5 (20-C), 78.9 (30-C), 75.9
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