全 文 ： 84 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): 00840086
doi: 10.3724/SP.J.1009.2013.00084
Chinese
Journal of
Natural
Medicines







A new carotane sesquiterpene from Walsura robusta
HOU Li1, 2, TANG Gui-Hua2, ZHANG Yu2, HAO Xiao-Jiang2,
ZHAO Qing1*, HE Hong-Ping1, 2*
1 Faculty of Pharmacy, Yunnan University of TCM, Kunming 650200, China;
2 State Key Laboratory of Photochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences,
Kunming 650201, China
Available online 20 Jan. 2013
[ABSTRACT] AIM: To study the chemical constituents from the leaves of Walsura robusta. METHODS: The leaves of W. robusta
were extracted with MeOH and compounds isolated by silica gel, Rp-C18, Sephadex LH-20 and semipreparative HPLC. These com-
pounds were elucidated by extensive spectroscopic analysis (MS, NMR, IR, and UV). RESULTS: Two sesquiterpenoids were obtained
and their structures were identified as 10-nitro-isodauc-3-en-15-al (1) and 10-oxo-isodauc-3-en-15-al (2). CONCLUSIONS: Com-
pound 1 was new with a nitro group. 1 and 2 were isolated from genus Walsura for the first time.
[KEY WORDS] Meliaceae; Walsura robusta; Sesquiterpenoid; Nitro compound
[CLC Number] R284.1 [Document code] A [Article ID] 1672-3651(2013)01-0084-03

1 Introduction
The genus Walsura (Meliaceae), comprising 16 species,
is naturally distributed in subtropical regions such as South-
ern China, India, and Indonesia[1]. In the previous literature,
triterpenoids, phenols, and steroids were isolated from this
genus, which exhibited cell protective, antioxidant and anti-
malarial activities [2-10]. The extracts of the leaves and twigs
of W. robusta Roxb., with the Chinese name “gesheshu” was
used as an insecticide in Xishuangbanna[5]. In order to seek
new natural products with bioactivities, the chemical con-
stituents of the leaves of W. robusta were studied. In this
paper, one new sesquiterpenoid 10-nitro-isodauc-3-en-15-al
(1) with a rare nitro group, along with one known compound,
10-oxo- isodauc-3-en-15-al (2)[11] were isolated. The struc-
ture of the new carotane sesquiterpenoid was elucidated on
the basis of spectroscopic analysis and comparison with the
related compounds reported in the literature. Compounds 1
and 2 showed no antimicrobial activities against Staphylo-

[Received on] 12-Apr.-2012
[Research funding] This project was supported by the Young Aca-
demic and Technical Leader Raising Foundation of Yunnan Province
(No. 2010CI047).
[*Corresponding author] HE Hong-Ping: Associate Prof., Tel/Fax.:
86-871-65223263, E-mail: hehongping@mail.kib.ac.cn;
qingzhaokm2008@126. com
These authors have no conflict of interest to declare.
coccus aureus, MRSA 92# (MRSA, methicillin-resistant S.
aureus), MRSA 98#, and MRSA 111#.


Fig. 1 Structures of compounds 1 and 2

2 Results and Discussion
10-Nitro-isodauc-3-en-15-al (1) was obtained as a color-
less oil, displaying a molecular formula of C15H23NO3 with
five degrees of unsaturation as determined by HR-EI-MS at
m/z 265.167 8 [M]+ (Calcd. for 265.167 8). The IR spectrum
showed the presence of aldehyde (1685 cm1) and nitro (1547
cm1, 1 385 cm1) groups. The 1H NMR and 13C NMR of 1
(Table 1) showed signals of three methyls (δH 0.93, d, J = 6.7
Hz, 6H and 1.23, s, 3H), a trisubstituted double bond moiety
(δH 6.53, J = 4.5 Hz, δC 157.7 and 141.2), and an aldehyde
group (δH 9.41, δC 192.1). These data suggested that 1 had the
same skeletal structure as aphanamol II[12], except for the
substituent at C-10. As is well known, the carbon signal of
the methine at δC 92.6 is at rather lower field comparison of
that of ordinary hydroxymethine in the same skeletal ses-
quiterpene, and the methine attached a nitro group was
therefore suggested[13]. The molecular formula (C15H23NO3)
HOU Li, et al. /Chinese Journal of Natural Medicines 2013, 11(1): 8486
2013年 1月 第 11卷 第 1期 Chin J Nat Med Jan. 2013 Vol. 11 No. 1 85

also confirmed the presence of a nitro group (NO2) in 1. The
methine was assigned at C-10 by means of the HMBC corre-
lation between H-14 with C-5, C-8, C-9, and δC 92.6. De-
tailed analysis of the 2D NMR data, including the HSQC,
1H-1H COSY, and HMBC data (Table 1 and Fig. 2), con-
firmed the planar structure of compound 1.

Table 1 1H (400 MHz) and 13C (100 MHz) NMR data of compound 1 in CDCl3
Carbon No. δH (multi, J in Hz) δC HMBC
1 2.24 (m), 1.90 (m) 23.4 CH2 C-2, C-3, C-9, C-10
2 2.79 (m), 2.20 (m) 18.9 CH2 C-1, C-3, C-4, C-10, C-15
3 141.2 C
4 6.53 (d, 4.5) 157.7 CH C-2, C-3, C-5, C-9, C-15
5 2.37 (dd, 8.4, 4.5) 54.4 CH C-14, C-3, C-4, C-6, C-9, C-10, C-11, C-15
6 1.88 (m) 54.9 CH C-4, C-7, C-11, C-12
7 1.89 (m), 1.47 (m) 27.1 CH2 C-6, C-8
8 1.67 (m), 1.47 (m) 39.2 CH2 C-6, C-7, C-10, C-14
9 45.7 C
10 4.27 (dd, 11.7, 4.6) 92.6 CH C-5, C-8, C-9, C-14
11 1.62 (m) 32.6 CH C-6, C-7, C-12
12 0.93 (d, 6.7) 19.6 CH2 C-6, C-11, C-13
13 0.93 (d, 6.7) 22.0 CH3 C-6, C-11, C-12
14 1.23 (s) 21.0 CH3 C-5, C- 8, C-9, C-10
15 9.41 (s) 192.1 CH C-2, C-3, C-4


Fig. 2 Key COSY, HMBC, and ROESY correlations of
compound 1

The relative configuration of 1 was established by the
ROESY correlations, as well as the coupling constants. Key
ROESY cross-peaks of H-5/H-14 and H-5/H-11 were ob-
served, which indicated that H-5 and the isopropyl group
were co-facial, arbitrarily assigned as -orientated, while H-6
was -oriented. The coupling constants of H-10 (dd, J = 4.6
and 11.7 Hz) indicated that the proton was -orientated. Ac-
cordingly, compound 1 was deduced as
10-nitro-isodauc-3-en-15-al.
The isolated sesquiterpenoids were screened for their an-
timicrobial activity against Staphyloccocus aureus, MRSA
92# (MRSA, methicillin-resistant S. aureus), MRSA 98#, and
MRSA 111# using the agar plate punch assay. The minimum
inhibitory concentrations (MICs) were determined by the
two-fold dilution method[14]. The results revealed that com-
pounds 1 and 2 showed no antimicrobial activities against
Staphylococcus aureus, MRSA 92#, MRSA 98#, and MRSA
111#.
3 Experimental
3.1 General experimental procedures
Optical rotations were measured with a Horiba
SEPA-300 polarimeter. UV spectra were detected on a Shi-
madzu UV-2401 spectrophotometer. IR spectra were deter-
mined on a Tenor 27 spectrophotometer with KBr pellet.
ESI-MS and HR-EI-MS were measured on a Finnigan MAT
90 instrument and Waters AutoSpec Premier P776, respec-
tively. 1D and 2D NMR spectra were recorded on Bruker
AM-400 and Bruker DRX-500 spectrometers with TMS as
internal standard. Semipreparative HPLC was performed on
an Agilent 1100 liquid chromatograph with a Zorbax SB-C18
column. Column chromatography was performed with silica
gel (38−48 m, Qingdao Marine Chemical, Inc., Qingdao,
People’s Republic of China), and MCI gel (75−150 m, Mit-
subishi Chemical Corporation, Tokyo, Japan). Fractions were
monitored by TLC, and spots were visualized by heating
silica gel plates sprayed with 5% H2SO4 in EtOH.
3.2 Plant material
The leaves of W. robusta were collected in Hainan Prov-
ince, People′s Republic of China in December 2010. The
plant was authenticated by Dr. HU Guang-Wan, Kunming
Institute of Botany, Chinese Academy of Sciences. A voucher
specimen (No. H20101202) was deposited in the State Key
Laboratory of Photochemistry and Plant Resources in West
China, Kunming Institute of Botany, CAS.
3.3 Extraction and isolation
The dried and powdered leaves (12 kg) of W. robusta
were extracted with MeOH three times under reflux, and the
solvent was evaporated in vacuo. The residue was partitioned
in water and extracted successively with petroleum ether and
EtOAc. The EtOAc fraction (200 g) was separated by silica
gel column chromatography (CC) eluted with a gradient of
HOU Li, et al. /Chinese Journal of Natural Medicines 2013, 11(1): 8486

86 Chin J Nat Med Jan. 2013 Vol. 11 No. 1 2013年 1月 第 11卷 第 1期

petroleum ether/Me2CO (50 : 1 to 1 : 1) and CHCl3/MeOH in
a gradient (15 : 1 to 3 : 1), to obtain eight fractions (Fr. A−H)
according to TLC monitor. Fr. E (57 g) was subjected to
MCI-gel column (MeOH/H2O, 6 : 4 to 9 : 1) to give eighteen
sub-fractions (E1−E18). Fr. E14 (8 g) was subjected to CC
eluted with CHCl3-Me2CO (200 : 1→100 : 1→50 : 1→25 :
1→15 : 1→10 : 1→5 : 1→1 : 1) to yield eleven fractions
(E14A−E14K. Fraction E14F was applied to a Sephadex
LH-20 column and then purified by HPLC to obtain 1 (17 mg)
and 2 (11 mg).
3.4 Antimicrobial and insecticidal assays
Antimicrobial assays were performed according to the
previously described protocols[14].
4 Identification
10-Nitro-isodauc-3-en-15-al (1) Colorless oil; [α]D19
10.1 (c 0.14, CHCl3); UV (CHCl3) max (log ) 241 (3.28)
nm; 1H NMR and 13C NMR data (see Table 1); IR max: 2 959,
2 837, 1 685, 1 547 cm1; HR-EI-MS m/z 265.167 8 [M]+
(Calcd. for C15H23NO3, 265.1678).
10-Oxo-isodauc-3-en-15-al (2) Colorless oil; C15H24O2;
1H NMR (CDCl3, 400 MHz) δ 9.28 (1H, s, H-15), 6.57 (1H,
d, 5.3 Hz, H-4), 1.58 (1H, m, H-11), 1.26 (3H, s, H-14), 0.88
(3H, s, H-12), 0.86 (3H, s, H-13); 13C NMR (CDCl3, 100
MHz); δ 212.3 (C, C-10), 192.7 (CH, C-15), 158.7 (CH, C-4),
143.7 (C, C-3), 59.6 (C, C-9), 55.4 (CH, C-6), 53.1 (CH, C-5),
38.9 (CH2, C-8), 35.1 (CH2, C-7), 32.4 (CH, C-11), 26.8
(CH2, C-1), 25.0 (CH3, C-14), 22.0 (CH3, C-13), 19.4 (CH3,
C-12), 19.6 (CH2, C-2).

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割舌树中一个新的胡萝卜烷型倍半萜
侯 丽 1, 2, 唐贵华 2, 张 于 2, 郝小江 2, 赵 庆 1*, 何红平 1, 2*
1云南中医学院中药学院, 昆明 650200;
2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, 昆明 650201
【摘 要】 目的:研究割舌树叶子的化学成分。方法：利用正相硅胶、反相 Rp-C18、凝胶 Sephadex LH-20、HPLC等色谱方
法对割舌树的甲醇提取部分进行分离纯化, 运用 MS、NMR、IR 和 UV 来鉴定化合物的结构。结果：从割舌树中分离得到两个
倍半萜 10-nitro-isodauc-3-en-15-al (1) 和 10-oxo-isodauc-3-en-15-al (2)。结论：化合物 1为新的硝基胡萝卜烷型倍半萜，化合物 1
和 2均为首次从该属植物中分离得到。
【关键词】 楝科; 割舌树; 倍半萜; 硝基化合物

【基金项目】 云南省中青年学术技术带头人后备人才项目(No. 2010CI047)资助