全 文 ： 74 Chin J Nat Med Jan. 2013 Vol. 11 No. 1 2013年 1月 第 11卷 第 1期

Chinese Journal of Natural Medicines 2013, 11(1): 00740076
doi: 10.3724/SP.J.1009.2013.00074
Chinese
Journal of
Natural
Medicines







A new guaiane-type sesquiterpene lactone from the
Chinese liverwort Porella acutifolia subsp. tosana
LI Rui-Juan, GUO Dong-Xiao, LOU Hong-Xiang*
Department of Natural Products Chemistry, School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China
Available online 20 Jan. 2013
[ABSTRACT] AIM: To study the chemical constituents of the Chinese liverwort Porella acutifolia subsp. tosana. METHODS: The
compounds were isolated and purified with column chromatography and their structures were determined on the basis of 1D- and
2D-NMR analysis. RESULTS: Three compounds were obtained and identified as guaian-3-en-2α, 14-6α, 12-diolide (1), (20R)-6-
hydroxystigmasta-4, 22-dien-3-one (2), and (20R)-3-hydroxystigmasta-5, 22-dien-7-one (3). CONCLUSION: Compound 1 is a new
guaiane-type sesquiterpene lactone. Compounds 2 and 3 are known steroids.
[KEY WORDS] Liverwort; Porella acutifolia subsp. tosana; Guaiane-type sesquiterpene lactone
[CLC Number] R284.1 [Document code] A [Article ID] 1672-3651(2013)01-0074-03

1 Introduction
Porella species are rich sources of sesqui- and diterpe-
noids, some of which show interesting biological activities,
such as antimicrobial activity against Gram positive bacteria,
ornithine decarboxylase inhibitory activity, and inhibition of
germination of higher plants[13]. The genus Porella com-
prises two groups: pungent and non-pungent species[12]. P.
acutifolia subsp. tosana belongs to the latter, and is distrib-
uted in China and Japan, The chemical investigation of P.
acutifolia subsp. tosana[4] led to the isolation of a new
guaiane sesquiterpene lactone, named as guaian-3-en-2α,
14-6α, 12-diolide (1) and two known steroids,
(20R)-6-hydroxystigmasta-4, 22-dien-3-one (2)[56], and
(20R)-3-hydroxystig-masta-5, 22-dien-7-one (3)[78].
2 Results and Discussion
Compound 1 was obtained as a white powder. The mo-
lecular formula of C15H18O4 was established by HRESI-MS
at m/z 263.128 1 [M + H]+ (Calcd. 263.127 8). IR spectrum
showed a broad band at 1 755 cm1 indicating the existence
of a γ-lactone group. Its 1H NMR data (Table 1) exhibited

[Received on] 17-Jan-2012
[Research funding] This project was supported by the National
Natural Science Foundation of China (No. 30925038).
[*Corresponding author] LOU Hong-Xiang: Prof., Tel: 86-531-
88382012, Fax: 86-531-88382019, E-mail: louhongxiang@sdu.edu.cn
These authors have no conflict of interest to declare.
signals of one vinylic proton at δH 5.63 (1H, d, J = 1.2 Hz),
two oxygenated methine protons at δH 5.34 (1H, dd, J = 7.2,
2.4 Hz) and δH 4.12 (1H, t, J = 9.0 Hz), a typical α-methyl
group of a γ-lactone at δH 1.27 (3H, d, J = 6.6 Hz), and a
vinylic methyl group δH 1.90 (3H, s). The 13C NMR data
(Table 1) and the HSQC spectrum displayed 15 carbon sig-
nals, which were classified as two methyls (a tertiary methyl

Tabel 1 1H NMR (600 MHz) and 13C NMR (150 MHz) data
of compound 1 in CDCl3
Position δC δH
1 47.5 2.99 (dt, J = 10.8, 7.0 Hz)
2 84.4 5.34 (dd, J = 7.2, 2.4 Hz)
3 125.1 5.63 (d, J = 1.2 Hz)
4 146.7
5 52.4 2.96 (t, J = 7.8 Hz)
6 84.2 4.12 (t, J = 9.0 Hz)
7 48.5 1.97 (m)
8α 31.6 1.44 (m)
8β 2.24 (m)
9α 27.8 2.42 (m)
9β 1.44 (m)
10 42.0 2.31 (t, J = 11.0 Hz)
11 41.6 2.26 (m)
12 177.9
13 13.3 1.27 (d, J = 6.6 Hz)
14 176.9
15 15.2 1.90 (s)
LI Rui-Juan, et al. /Chinese Journal of Natural Medicines 2013, 11(1): 7476
2013年 1月 第 11卷 第 1期 Chin J Nat Med Jan. 2013 Vol. 11 No. 1 75

at δC 15.2 and a secondary methyl at δC 13.3), two methyl-
enes (δC 31.6 and 27.8), eight methines (including an olefinic
carbon at δC 125.1 and two oxygenated carbons at δC 84.4
and 84.2), and three quaternary carbons (including an olefinic
carbon at δC 146.7 and two lactone carbonyl carbons at δC
177.9 and 176.9). The 1H-1H COSY correlations of H-2/H-1,
H-1/H-10, H-10/H2-9, H2-8/H-7, H-7/H-6, H-6/H-5 afforded
the partial structure (shown as bold lines in Fig. 2). In the
HMBC spectrum (Fig. 2), the correlations between H-1 with
C-2, C-3, C-4 and C-5 indicated a five-membered ring and
allowed the connectivity of C-1 and C-5. The methyl signal
at δH 1.90 (H3-15) exhibited correlations with C-3 (δC 125.1),
C-4 (δC 146.7), and C-5, indicating that it was attached to C-4.
The methyl at δH 1.27 (d, J = 6.6 Hz, H3-13) correlated with
C-7, C-11, and C-12, and the chemical shift of C-12 (δC
177.9) indicated an α-methyl-γ-lactone. Similarly, the HMBC
correlations of H-9/C-10, H-9/C-14, and H-10/C-14, and the
chemical shift of C-14 (δC 176.9) indicated another γ-lactone.
On the basis of the above spectral evidence and discussion,
the planar structure of 1 was determined as depicted. Previ-
ously, a similar guaiane-type sesquiterpene lactone, porel-
ladiolide, was isolated from the same species[23].
The relative configuration of compound 1 was confirmed
from analysis of the coupling constants and NOESY experi-
ment. The coupling constant between H-6 and H-7 (J =
9.0 Hz) suggested they were on the opposite side[3]. In the
NOESY spectrum, the correlations of H-1/H-7, H-5/H-7, and
H-7/H-13 indicated that they were on the same side of the
structure. Similarly, H-2, H-6, and H-10 were located on the
same side of the molecule based on the NOE correlations of
H-6/H-10 and H-2/H-10.
The other two compounds were identified as 6β-hydroxy-
(20R)-24-ethylcholest-4,22-dien-3-one (2) and 3β-hydroxy-
(20R)-24-ethylcholest-5,22-dien-7-one (3) by comparison of
their 1H and 13C NMR spectroscopic data with those re-
ported[5, 7].


Fig. 1 Structures of compounds 13


Fig. 2 Key 1H-1H COSY (▬) and HMBC (HC) correla-
tions of 1

3 Experimental
3.1 General experimental procedures
Optical rotations were measured on a GYROMAT-HP
polarimeter. IR spectra were recorded on a Thermo-Nicolet
670 spectrophotometer using KBr disks. NMR spectra were
measured on a Bruker Avance DRX-600 spectrometer oper-
ating at 600 (1H) or 150 (13C) MHz with TMS as internal
standard. HRESI-MS was carried out on a LTQ-Orbitrat XL
mass spectrometer. All solvents used were of analytical grade.
Column chromatography was performed on either silica gel
(48−75 μm; Qingdao Marine Chemical, Inc., Qingdao, China)
or Sephadex LH-20 (25−100 μm; Pharmacia). Semiprepara-
tive HPLC was performed on an Agilent 1100 liquid chroma-
tography with a Zorbax Eclipse XDB-C18, 4.6 mm × 150 mm
column. Fractions were monitored by TLC, and spots were
visualized under UV (254 nm) light and by heating silica gel
plates which were sprayed with 10% H2SO4 in EtOH.
3.2 Plant material
Porella acutifolia subsp. tosana was collected from
Mount Leigong, Guizhou Province, China and identified by
Prof. XIONG Yuan-Xin (College of Life Sciences, Guizhou
University, Guizhou). A voucher specimen (No. 2009071106)
has been deposited at the Department of Natural Products
Chemistry, School of Pharmaceutical Sciences, Shandong
University.
3.3 Extraction and isolation
Dried and powdered liverwort P. acutifolia subsp. tosana
(300 g) was extracted with 95% EtOH (3 L × 3) and the solu-
tion was concentrated under reduced pressure. The concen-
trated extract (9 g) was partitioned successively with Et2O
(100 mL × 3) and n-BuOH (100 mL × 3). The Et2O extraction
(4 g) was subjected to silica gel column chromatography
(petroleum ether/acetone gradient) to give seven fractions
AG. Fraction B was eluted with petroleum ether/acetone
(30 : 1) to give four subfractions B1B4. Fraction B3 was
further purified by HPLC (MeOH/H2O, 93 : 7, 1.8 mL·min-1)
to obtain 2 (1.2 mg) and 3 (1.0 mg). Fraction D was chroma-
tographed over a Sephadex LH-20 column (CH2Cl2/MeOH,
1 : 1), then separated with silica gel column (petroleum eth-
er/acetone, 15 : 1) to afford compound 1 (2.0 mg).
LI Rui-Juan, et al. /Chinese Journal of Natural Medicines 2013, 11(1): 7476
76 Chin J Nat Med Jan. 2013 Vol. 11 No. 1 2013年 1月 第 11卷 第 1期

4 Identification
Guaian-3-en-2α, 14-6α, 12-diolide (1) White amor-
phous powder; [α]20D 60.0° (c 0.24, CHCl3); IR (KBr) νmax: 3
495, 2 969, 2 952, 2 871, 1 755, 1 644 cm−1; C15H18O4;
HRESI- MS m/z 263.128 1 [M + H]+ (Calcd. for m/z
C15H19O4 263.127 8); 1H and 13C NMR, see Table 1.
(20R)-6-Hydroxystigmasta-4, 22-dien-3-one (2) Col-
orless needle crystals (CHCl3); C29H46O2; mp 187−189 ºC;
1H NMR (600 MHz, CDCl3) δH: 0.74 (s, H3-18), 0.77 (d, J =
7.2 Hz, H3-27), 0.79 (t, J = 7.2 Hz, H3-29), 0.82 (d, J = 6.0
Hz, H3-26), 1.00 (d, J = 6.6 Hz, H3-21), 1.36 (s, H3-19), 4.33
(s, H-6), 5.00 (dd, J = 15.0, 9.0 Hz, H-23), 5.12 (dd, J = 15.0,
9.0 Hz, H-22), 5.80 (s, H-4); 13C-NMR (150 MHz, CDCl3) δC:
37.0 (C-1), 34.3 (C-2), 200.5 (C-3), 126.4 (C-4), 168.4 (C-5),
73.3 (C-6), 38.5 (C-7), 29.7 (C-8), 53.6 (C-9), 38.0 (C-10),
20.9 (C-11), 39.5 (C-12), 42.4 (C-13), 56.0 (C-14), 24.2
(C-15), 28.9 (C-16), 55.9 (C-17), 12.3 (C-18), 19.5 (C-19),
40.5 (C-20), 21.2 (C-21), 138.1 (C-22), 129.4 (C-23), 51.2
(C-24), 31.9 (C-25), 19.0 (C-26), 21.2 (C-27), 25.4 (C-28),
12.2 (C-29); EI-MS (int. rel) m/z 427.8 [M + H]+.
(20R)-3-Hydroxystigmasta-5, 22-dien-7-one (3) Col-
orless needle crystals (CHCl3); C29H46O2; mp 150−152 ºC;
1H NMR (600 MHz, CDCl3) δH: 0.69 (s, H3-18), 0.79 (d, J =
6.6 Hz, H3-27), 0.81 (t, J = 7.2 Hz, H3-29), 0.85 (d, J = 6.5
Hz, H3-26), 1.03 (d, J = 6.5 Hz, H3-21), 1.21 (s, H3-19), 3.69
(m, H-3), 5.02 (dd, J = 8.4, 15.0 Hz, H-23), 5.16 (dd, J = 8.4,
15.2 Hz, H-22), 5.70 (d, J = 1.7 Hz, H-6); 13C NMR (150
MHz, CDCl3) δC: 36.4 (C-1), 31.9 (C-2), 70.6 (C-3), 41.8
(C-4), 165.1 (C-5), 126.1 (C-6), 202.3 (C-7), 45.4 (C-8), 50.0
(C-9), 38.3 (C-10), 21.2 (C-11), 38.6 (C-12), 43.0 (C-13),
50.0 (C-14), 26.4 (C-15), 29.1 (C-16), 54.7 (C-17), 12.2
(C-18), 17.3 (C-19), 40.3 (C-20), 21.4 (C-21), 138.1 (C-22),
129.5 (C-23), 51.2 (C-24), 31.2 (C-25), 21.1 (C-26), 19.0
(C-27), 25.4 (C-28), 12.3 (C-29); EI-MS (int. rel) m/z 427.8
[M + H]+.
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尖瓣光萼苔(东亚亚种)中的一个新愈创木烷型倍半萜内酯化合物
李瑞娟, 郭东晓, 娄红祥*
山东大学药学院天然药物化学教研室, 济南 250012
【摘 要】 目的：研究中国尖瓣光萼苔(东亚亚种)的化学成分。方法：采用多种柱色谱技术分离，运用 NMR、MS、IR等
多种波谱技术鉴定化合物的结构。结果：从尖瓣光萼苔(东亚亚种)中分离得到 3个化合物，分别为 guaian-3-en-2α, 14-6α, 12-diolide
(1)、(20R)-6-hydroxystigmasta-4, 22-dien-3-one (2)和(20R)-3-hydroxystigmasta-5, 22-dien-7-one (3)。结论：化合物 1为新化合物，
化合物 2和 3为已知甾体。
【关键词】 苔纲植物; 尖瓣光萼苔(东亚亚种); 愈创木烷型倍半萜内酯

【基金项目】 国家自然科学基金(No. 30925038)资助项目