Two new lignans and anti-HBV constituents from Illicium henryi

Article abstract of DOI:10.1002/cbdv.201000110

Two new lignans, dihydrodehydrodiconiferyl alcohol 9-O-β-D-(3′- O-acetyl)-xylopyranoside (1) and threo-4,9,9′-trihydroxy-3,3′- dimethoxy-8-O-4′-neolignan 7-O-α-rhamnopyranoside (2) were isolated from Illicium henryi, together with ten known compounds, 3-1

Full text of DOI:10.1002/cbdv.201000110

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CHEMISTRY & BIODIVERSITY – Vol. 8 (2011)
Two New Lignans and Anti-HBV Constituents from Illicium henryi
by Ji-Feng Liua)b), Zhi-Yong Jiang*a), Chang-An Genga)b), Quan Zhanga)b), Yao Shic),
Yun-Bao Maa), Xue-Mei Zhanga), and Ji-Jun Chen*a)
a) State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of
Botany, Chinese Academy of Sciences, Kunming 650204, P. R. China
(phone: þ86-871-5223265; fax: þ86-871-5223265; e-mail: chenjj@mail.kib.ac.cn,
jiangzy@mail.kib.ac.cn)
b) Graduate School of Chinese Academy of Sciences, Beijing 100039, P. R. China
c) Hawley & Hazel Chemical (ZS) Co., Ltd, Zhongshan 528411, P. R. China
Two new lignans, dihydrodehydrodiconiferyl alcohol 9-O-b-d-(3’’-O-acetyl)-xylopyranoside (1) and
threo-4,9,9’-trihydroxy-3,3’-dimethoxy-8-O-4’-neolignan 7-O-a-rhamnopyranoside (2) were isolated
from Illicium henryi, together with ten known compounds, 3–12. Their structures were elucidated by
extensive spectroscopic analyses. The anti-hepatitis B virus (anti-HBV) activity of compounds 1–12
inhibiting HBV surface antigen (HBsAg) and HBV e antigen (HBeAg) secretion on Hep G2.2.15 cell
line was evaluated. (ꢀ)-Dihydrodehydrodiconiferyl alcohol (4) showed moderate inhibitory activity on
both HBsAg and HBeAg secretion with IC50 values of 0.06 and 0.53 mm, respectively.
Introduction. – The genus Illicium belongs to the single-genus family Illiciaceae.
Previous chemical investigations on this genus yielded prenylated C6-C3 compounds,
neolignans, and a large number of unique sesquiterpene lactones exhibiting neurotoxic
and neurotrophic activities [1–3]. From a chemotaxonomic point of view, the Illicium
species are interesting sources, rich in biosynthetically unique sesquiterpenes which are
considered to be characteristic chemical markers [4]. In addition, the prenylated C6-C3
compounds, referred to as phytoquinoids, are also considered to be characteristic
constituents, some of which are found to increase choline acetyltransferase activity [5].
I. henryi is a shrub distributed in the southwestern part of China, and its bark and roots
have been used as a folk-medicinal herb for dispelling wind-evil and assuaging pain [6].
In the previous studies, sesquiterpene lactones [7] and flavonoids [8] had been isolated
from the title plant. Here, we describe the isolation and structure elucidation of two
new lignans, 1 and 2, along with ten known compounds, 3–12, which were isolated from
the EtOH extract of the stems and roots of I. henryi for the first time, and the
assessment of their anti-HBV activity.
Results and Discussion. – 1. Structure Elucidation. Compound 1 was obtained as
white amorphous powder. HR-ESI-MS showed the [MþCl]ꢀ ion peak at m/z 569.1775
(calc. 569.1789) in accordance with the molecular formula C27H34O11, indicating eleven
degrees of unsaturation. The IR spectrum showed the presence of OH (3430 cmꢀ1) and
CO (1733 cmꢀ1) groups, as well as aromatic rings (1610, 1500, 1464 cmꢀ1). The
1H-NMR spectrum displayed ABX spin-system signals at d(H) 6.97 (s, 1 H), 6.83 (dd,
ꢀ 2011 Verlag Helvetica Chimica Acta AG, Zꢁrich

CHEMISTRY & BIODIVERSITY – Vol. 8 (2011)
693
J¼8.0, 1.6, 1 H), and 6.74 (overlapped, 1 H), aromatic H-atom signals at d(H) 6.76 (s,
1 H), 6.72 (s, 1 H), two MeO signals at d(H) 3.81 (s), 3.84 (s), and an anomeric H-atom
signal at d(H) 4.38 (d, J¼7.5 ) . The 13C-NMR (DEPT; Table 1) spectrum revealed the
presence of three Me, five CH2, and twelve CH groups, and eight quaternary C-atoms.
The CO C-atom signal at d(C) 172.6 and a Me signal at d(C) 21.1 suggested the
presence of an AcO moiety in compound 1. Analysis of NMR spectra revealed that
compound 1 was almost identical with dihydrodehydrodiconiferyl alcohol 9-O-b-d-
xylopyranoside (6) [9], except for the presence of the signals due to an AcO moiety.
The cross-peak between HꢀC(3’’) and C(1’’’) (d(C) 172.6) observed in the HMBC
spectrum indicated that the AcO group was linked to C(3’’) (Fig.). Hydrolysis of
compound 1 with 1m NaOH gave 1a. The NMR data of 1a were identical to those of 6.
The value of coupling constant of HꢀC(7)1) (J¼6.4 Hz) along with the ROESY
correlation HꢀC(7)/HꢀC(9) (Fig.) indicated that HꢀC(7) and HꢀC(8) were in a trans-
configuration [10][11]. The b-configuration of the anomeric C-atom was established by
1
)
Numbering as indicated in the Formulae; for systematic names, cf. the Exper. Part.

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CHEMISTRY & BIODIVERSITY – Vol. 8 (2011)
Table 1. 1H- and 13C-NMR Data of Compounds 1 and 2. Recorded at 400 and 100 MHz, respectively, in
CD3OD; d in ppm, J in Hz.
Position1)
1
2
d(H)
d(C)
d(H)
d(C)
1
2
3
4
5
6
7
8
9
1’
2’
3’
4’
5’
6’
7’
–
129.5 (s)
110.6 (d)
149.0 (s)
147.4 (s)
116.0 (d)
119.7 (d)
89.0 (d)
52.9 (d)
72.2 (t)
137.0 (s)
114.0 (d)
145.2 (s)
147.4 (s)
134.5 (s)
118.0 (t)
32.9 (t)
35.8 (t)
62.2 (t)
104.6 (d)
73.0 (d)
78.7 (d)
69.4 (d)
66.7 (t)
–
–
129.7 (s)
112.5 (d)
148.6 (s)
148.1 (s)
116.2 (d)
122.1 (s)
76.2 (d)
84.4 (d)
61.0 (t)
136.4 (s)
113.4 (d)
150.9 (s)
146.9 (s)
117.3 (d)
121.0 (d)
32.4 (t)
35.7 (t)
61.4 (t)
98.4 (d)
73.0 (d)
72.5 (d)
74.2 (d)
70.5 (d)
18.9 (q)
–
6.97 (s)
–
–
7.33 (d, J¼1.5)
–
–
6.74 (overlapped)
7.21 (d, J¼8.1)
7.14 (d, J¼8.0)
5.69 (d, J¼5.4)
4.96–4.99 (m)
4.29–4.30 (m), 3.38–3.40 (m)
–
6.83 (dd, J¼8.0, 1.6)
5.53 (d, J¼6.4)
3.57–3.61 (m)
3.88–3.92 (m), 3.27–3.30 (m)
–
6.72 (s)
–
–
–
6.85 (d, J¼1.7)
–
–
7.25 (d, J ¼ 8.2)
6.77 (dd, J¼8.2, 1.6)
2.76 (t, J¼7.3)
1.97–2.04 (m)
3.86 (t, J¼6.4)
5.36 (br. s)
4.61–4.65 (m)
4.59–4.61 (m)
4.30–4.33 (m)
4.67–4.71 (m)
1.68 (d, J¼6.1)
–
6.76 (s)
2.61 (t, J¼7.6)
1.78–1.82 (m)
3.56 (t, J¼6.4)
4.38 (d, J¼7.5)
3.34–3.36 (m)
4.85–4.87 (m)
3.58–3.63 (m)
3.98–4.02 (m), 3.81–3.84 (m)
–
8’
9’
1’’
2’’
3’’
4’’
5’’
6’’
1’’’
2’’’
MeO
MeO
–
172.6 (s)
21.1 (q)
56.4 (q)
56.7 (q)
2.10 (s)
3.81 (s)
3.84 (s)
–
–
3.60 (s)
3.65 (s)
55.7 (q)
55.8 (q)
1
the coupling constant of HꢀC(1’’) (J¼7.5 Hz) as observed in the H-NMR spectrum
[9]. Thus, compound 1 was deduced as dihydrodehydrodiconiferyl alcohol 9-O-b-d-(3’’-
O-acetyl)xylopyranoside.
Compound 2 was isolated as white amorphous powder. HR-ESI-MS exhibited the
[MþCl]ꢀ ion peak at m/z 559.1961 (calc. 559.1946), indicating the molecular formula
C26H36O11. The IR spectrum suggested the presence of a OH group (3416 cmꢀ1) and an
aromatic ring (1607, 1513, 1454 cmꢀ1). The 1H-NMR spectrum displayed the signals of
one C3 unit at d(H) 2.01 (m, CH2(8’)), 2.76 (t, J¼7.3, CH2(7’)), and 3.86 (t, J¼6.4,
CH2(9’)), two MeO groups (d(H) 3.60 (s), 3.65 (s)), two CH groups (d(H) 4.98 (m,
HꢀC(8)), 5.69 (d, J¼5.4, HꢀC(7)), a rhamnosyl moiety, and six aromatic H-atoms
(two ABX-type spin systems). The 13C-NMR (DEPT; Table 1) spectra revealed the
presence of three Me, four CH2, and 13 CH groups, and six quaternary C-atoms,
suggesting the presence of two C6-C3 units and a sugar moiety. Comparing the NMR
data of compound 2 with those of threo-4,9,9’-trihydroxy-3,3’-dimethoxy-8-O-4’-
neolignan 7-O-b-d-glucopyranoside (3) [12], indicated that they were similar except

CHEMISTRY & BIODIVERSITY – Vol. 8 (2011)
695
Figure. Key HMBC (!) and ROESY ($) correlations of 1 and 2
for the signals of the sugar moiety. The acid hydrolysis of compound 2 with 2m HCl
afforded rhamnose and the aglycone 2a. The rhamnose was identified by HP-Si-TLC
with authentic sample. The a-configuration of the rhamnosyl residue was confirmed by
1H,13C-NMR data [13][14]. The configuration of C(7) and C(8) was determined as
threo based on the large coupling constant (J(7,8)¼7.2) in the 1H-NMR spectrum of 2a
[12], which was also supported by the ROESY correlation of HꢀC(7) and HꢀC(8), as
shown in the Figure. Consequently, the structure of compound 2 was determined to be
threo-4,9,9’-trihydroxy-3,3’-dimethoxy-8-O-4’-neolignan 7-O-a-rhamnopyranoside.
The known compounds, threo-4,9,9’-trihydroxy-3,3’-dimethoxy-8-O-4’-neolignan 7-
O-b-d-glucopyranoside (3) [12], (ꢀ)-dihydrodehydrodiconiferyl alcohol (4) [15],
ficusal (5) [16], dihydrodehydrodiconiferyl alcohol 9-O-b-d-xylopyranoside (6) [9],
dihydrodehydrodiconiferyl alcohol 9-O-a-l-rhamnopyranoside (7) [17], sakuraresinol
(8) [18], 2,3-dihydro-2-[3’-methoxy-4’-(1’’,3’’-dihydroxy-2’’-propyloxy)phenyl]-3-(hy-
droxymethyl)-7-methoxybenzofuran-5-propanol (9) [10], 4-O-[2’-hydroxy-1’-(hydroxy-
methyl)ethyl]dihydroconiferyl alcohol 6’’-(p-hydroxybenzoyl)-b-d-glucopyranoside
(10) [19], 4-O-[2’-hydroxy-1’-(hydroxymethyl)ethyl]dihydroconiferyl alcohol vanillo-
yl-glucoside (11) [13], and breynioside A (12) [20] were identified by comparison of
their spectroscopic data with those reported.
2. Anti-HBV Assay. The isolated compounds 1–12 were evaluated for their anti-
HBV activity on the HBV-transfected Hep G 2.2.15 cell line in vitro according to our
previous report [21]. The results including their activities and cytotoxicities were
compiled in Table 2. The results show that the benzofuran lignans exhibited anti-HBV
activities with reduced cytotoxicities for the glycoside derivatives 1, 6, and 7. (ꢀ)-
Dihydrodehydrodiconiferyl alcohol (4) was the most active showing moderate
inhibitory activity (IC50 ¼0.06 mm, SI¼8.8) on HBV surface antigen (HBsAg)

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CHEMISTRY & BIODIVERSITY – Vol. 8 (2011)
secretion in Hep G2.2.15 cells. The new compound dihydrodehydrodiconiferyl alcohol
9-O-b-d-(3’’-O-acetyl)xylopyranoside (1) possessed weak activity against HBsAg
secretion with an IC50 value of 0.58 mm and CC50 value of 0.92 mm.
Table 2. Anti-HBV Activities of Compounds 1–12a)
Compounds
CC50 [mm]
HBsAgb)
HBeAgc)
IC50 [mm]
SId)
1.6
IC50 [mm]
SId)
1
2
3
0.92
>1.85
1.15
0.58
>1.85
0.59
0.06
0.15
1.67
0.93
0.95
3.62
>2.40
>1.85
0.80
0.50
0.52
>2.15
2.45
>2.59
4.56
>1.93
>2.87
1.43
<0.4
–
1.4
1.1
0.5
–
0.7
<0.4
1.0
–
–
1.9
8.8
1.8
>1.3
1.9
1.0
1.2
–
4
0.53
5
0.27
6
7
>2.15
1.76
8
0.95
9
4.52
10
11
>1.93
>2.87
1.17
>1.93
1.65
1.28
>1.7
0.9
2.8
–
0.8
1.4
12
3TCe)
28.0
10.0
20.0
a) All values are the means of two independent experiments. b) HBsAg: HBV surface antigen.
c) HBeAg: HBV e antigen. d) CC50: 50% Cytotoxic concentration, IC50: 50% inhibition concentration
against HBV synthesis, SI¼CC50/IC50. e) 3TC: Lamivudine, an antiviral agent used as a positive control.
This work was supported by National Science Foundation of China for Distinguished Young Scholars
(No. 81025023), Xibu Zhiguang Joint-Scholarship of Chinese Academy of Sciences, and the External
Cooperation Program of Chinese Academy of Sciences (No. GJHZ200818) and CAS–Croucher
Foundation (CAS-CF07/08.SC03). We thank the staff of the analytical group of the State Key Laboratory
of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy
of Sciences.
Experimental Part
General: Column chromatography (CC): Silica gel (SiO2; 200–300 mesh; Qingdao Meigao Chemical
Company, Qingdao, P. R. China), D101 macroporous resin (Tianjin Pesticide Chemical Company, Tianjin,
P. R. China), Lichrospher Rp-18 gel (40–63 mm; Merck Chemicals Ltd., Germany), and Sephadex LH-20
(20–150 mm; Pharmacia Fine Chemical Co. Ltd., Sweden). Prep. HPLC: Waters 600 (Waters, Milford,
USA), with a Waters Xterra Prep RP-18 (7.8ꢁ300 mm, 10 mm) column (Waters, Ireland). Optical
rotations: Horiba SEPA-300 polarimeter (Horiba, Tokyo, Japan). UV Spectra: Shimadzu UV-210A
spectrophotometer (Shimadzu, Kyoto, Japan). IR Spectra: Bio-Rad FTS-135 spectrometer (Bio-Rad,
California, USA); as KBr pellets. 1D- and 2D-NMR spectra: Bruker AM-400 NMR and DRX-500
spectrometers with TMS as internal standard (Bruker, D-Bremerhaven). MS: VG Auto Spec-3000
spectrometer (VG, GB-Manchester) and API Qstar Pulsar (Applied Biosystems, Foster City, USA); in
m/z.
Plant Material. The stems and roots of Illicium henryi Diels. were collected in Wenshan, Yunnan
Province, P. R. China, in July 2006, and identified by Prof. Ligong Lei from Kunming Institute of Botany,
Chinese Academy of Sciences. A voucher specimen (2006-07-01) was deposited with the Laboratory of
Antivirus and Natural Medicinal Chemistry, Kunming Institute of Botany.

CHEMISTRY & BIODIVERSITY – Vol. 8 (2011)
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Extraction and Isolation. Dried and powdered plant material (9 kg) was extracted with 95% EtOH
(40 l) under reflux for three times, 2 h for each time. The extract was concentrated in vacuo, and then
partitioned between CHCl3, BuOH, and H2O successively. The BuOH fraction (200 g) was dissolved in
H2O. The H2O-soluble fraction was passed through a D101 macroporous adsorptive resin column and was
eluted with H2O/EtOH (100 :0, 80 :20, 60 :40, 40 :60, 20 :80, 0 :100 (v/v)) to yield ten fractions, Frs. 1–10.
The Fr. 3 (10 g) was repeatedly subjected to CC (SiO2 (5ꢁ41 cm, 350 g); CHCl3/Me2CO 90 :10, 80 :20,
70 :30, 50 :50, 30 :70 (v/v; each 4 l) to give five fractions, Frs. 3a–3e. By further purification on Rp-18 gel
(2.5ꢁ33 cm, 120 g) with MeOH/H2O (30 :70, 40 :60, 50 :50, 60 :40 (v/v; each 500 ml), compounds 1
(15 mg), 2 (13 mg), and 6 (40 mg) were obtained from Fr. 3b. Fr. 4 (8 g) was subjected to CC (Rp-18 gel
(2.5ꢁ33 cm, 120 g); MeOH/H2O 10 :90, 80 :20, 40 :60, 60 :40, 80 :20, 0 :100 (v/v)) to afford seven
fractions, Frs. 4a–4g. Fr. 4b was subjected to CC (SiO2 (2ꢁ35 cm, 50 g); CHCl3/MeOH 90 :10) to yield
compound 7 (9 mg). Fr. 4f was separated by repeated SiO2 CC to yield compound 3 (12 mg) eluted with
CHCl3/MeOH 90 :10, followed by AcOEt/MeOH 95 :5. Fr. 5 (12 g) was subjected to CC (SiO2 (5ꢁ
35 cm, 260 g); CHCl3/Me2CO 100 :0, 90 :10, 80 :20 (v/v); each 3 l) to afford five fractions, Frs. 5a–5e.
Fr. 5a (1.2 g), Fr. 5b (1 g), and Fr. 5d (1.8 g) were further separated by CC (SiO2 (3ꢁ25 cm, 70 g);
petroleum ether (PE)/Me2CO 75 :25, PE/AcOEt 60 :40, and CHCl3/Me2CO 85 :15, resp.) to furnish
compounds 4 (6 mg), 5 (8 mg), and 8 (8 mg). Fr. 7 (5 g) was further separated by CC (SiO2 (3ꢁ30 cm,
85 g); PE/Me2CO 85 :15, 70 :30, 50 :50, 30 :70 (v/v); each 700 ml) to give six fractions, Frs. 7a–7f. Fr. 7c
was further purified by CC (Rp-18 (2.5ꢁ33 cm, 120 g); MeOH/H2O 65 :35) to provide compound 10
(11 mg). Fr. 7d (50 mg) and Fr. 7f (50 mg) were further purified by CC (Sephadex LH-20 (1.4ꢁ150 cm,
48 g), MeOH), then purified by semi-prep. HPLC, using a Waters XTerra Prep RP-18 column, eluted
with MeOH/H2O 40 :60 (flow rate 4.5 ml/min; detection at 254 nm) to obtain compounds 11 (4 mg, tR
20 min) and 12 (19 mg, tR 35 min), resp.
Dihydrodehydrodiconiferyl Alcohol 9-O-b-d-(3’’-O-Acetyl)xylopyranoside (¼ [(2S,3R)-2,3-Dihy-
dro-2-(4-hydroxy-3-methoxyphenyl)-5-(3-hydroxypropyl)-7-methoxy-1-benzofuran-3-yl]methyl 3-O-
Acetyl-b-d-xylopyranoside; 1). White amorphous powder. [a]2D7:9 ¼ ꢀ4.6 (c¼0.215, MeOH). UV
(CHCl3): 282 (3.73). IR (KBr): 3430, 2934, 1733, 1610, 1518, 1500, 1464, 1244, 1213, 1039, 974, 755.
1H- and 13C-NMR: see Table 1. HR-ESI-MS: 569.1775 ([MþCl]ꢀ , C27H34ClO1ꢀ1 ; calc. 569.1789).
threo-4,9,9’-Trihydroxy-3,3’-dimethoxy-8-O-4’-neolignan 7-O-a-Rhamnopyranoside (¼(1R,2R)-3-
Hydroxy-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]propyl 6-Deoxy-
a-l-mannopyranoside; 2). White amorphous powder. [a]2D6:1 ¼ ꢀ36.4 (c¼0.055, MeOH). UV (CHCl3):
224 (4.16), 280 (3.71). IR (KBr): 3416, 2930, 1607, 1513, 1454, 1273, 1129, 1035, 983, 812. 1H- and
13C-NMR: see Table 1. FAB-MS (neg.): 523 ([MꢀH]ꢀ ), 359, 329, 283. HR-ESI-MS: 559.1961 ([Mþ
Cl]ꢀ , C26H36ClO1ꢀ1 ; calc. 559.1946).
Hydrolysis of Compound 1. 2m NaOH (1 ml) was added to a soln. of 1 (7 mg) in MeOH (1 ml), which
was stirred for 12 h at r.t. The mixture was diluted with 1m HCl (5 ml) and extracted with AcOEt (3ꢁ
5 ml). The AcOEt layer was washed with brine (10 ml), dried (Na2SO4), and concentrated under
reduced pressure to give a crude residue, which was purified by CC (SiO2; CHCl3/MeOH 90 :10) to yield
1a (3 mg).
Hydrolysis of Compound 2. The mixture of 2 (6 mg), 2m HCl (1 ml), and MeOH (1 ml) was heated
in a water bath at 508 for 12 h. After reaction, the mixture was diluted with H2O (10 ml) and extracted
with AcOEt (3ꢁ5 ml). The AcOEt layer was washed with brine (10 ml) and dried (MgSO4), and
concentrated under reduced pressure to give a crude residue which was purified by CC (SiO2; CHCl3/
MeOH 95 :5) to provide 2a (2 mg). The aq. layers were evaporated to dryness under reduced pressure.
The sugar was identified to be rhamnose by comparison with an authentic sample on HP-Si-TLC.
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Received April 26, 2010