全 文 ： 284 Chin J Nat Med July 2012 Vol. 10 No. 4 2012 年 7 月 第 10 卷 第 4 期

Chinese Journal of Natural Medicines 2012, 10(4): 02840286
doi: 10.3724/SP.J.1009.2012.00284
Chinese
Journal of
Natural
Medicines







A new triterpene from Glinus oppositifolius
Consolacion Y. Ragasa1*, Dinah L. Espineli1, Emelina H. Mandia2, Ming-Jaw Don3,
Chien-Chang Shen3
1Chemistry Department and Center for Natural Sciences and Ecological Research, De La Salle University, Manila 1004, Philippines;
2Biology Department and Center for Natural Sciences and Ecological Research, De La Salle University, Manila 1004, Philippines;
3National Research Institute of Chinese Medicine, Taipei 112, Taiwan, China
Available online 20 July 2012
[ABSTRACT] AIM: To investigate the chemical constituents of Glinus oppositifolius. METHODS: The compounds were isolated by
silica gel chromatography. The structure of the new triterpene was elucidated by extensive 1D and 2D NMR spectroscopy. RESULTS:
The dichloromethane extract of the air-dried leaves of Glinus oppositifolius afforded a new triterpene, oppositifolone (1), spinasterol
(2), squalene (3) and lutein (4). The structure of 1 was elucidated by NMR spectroscopy, while 2−4 were identified by comparison of
their 13C NMR data with those reported in the literature. CONCLUSION: A new triterpene was isolated from G. oppositifolius.
[KEY WORDS] Glinus oppositifolius; Molluginaceae; Oppositifolone; Spinasterol; Squalene; Lutein
[CLC Number] R284.1 [Document code] A [Article ID] 1672-3651(2012)04-0284-03

1 Introduction
Glinus oppositifolius (L.) Aug. DC. (Molluginaceae) is a
much branched, ascending or almost prostrate annual plant
growing to about 40 cm height. It is commonly found in des-
iccated localities within the tropics at low elevations. The
plant is reported to be rich in iron and calcium and is used as
a vegetable in Africa, India, and the Philippines[1]. It is also
used as stomachic, uterine stimulant, and aperient[2]. It is
employed in the treatment of various illnesses such as joint
pains, inflammations, fever, malaria and wounds[3]. The lea-
ves are used as vegetable, as well as expectorant and antipy-
retic agent[4]. The 70% ethanolic extract of G. oppositifolius
scavenges free radicals and reduces lipid peroxidation[2]. The me-
thanolic extract of G. oppositifolius root enhanced the reco-
very from hepatic damage induced by CCl4 in albino rats[5].
Several studies have been conducted on the chemical
constituents of G. oppositifolius. L-()-(N-trans-cinnamoyl)-
arginine, kaempferol-3-O-galactopyranoside, isorhamnetin
3-O--D-xylopyranosyl-(12)--D-galactopyranoside, vite-
xin, vicenin-2, adenosine and L-phenylalanine[4] were iso-
lated from the whole plant of G. oppositifolius. Two pectin

[Received on] 21-July-2011
[Research funding] This project was supported by Science Founda-
tion of De La Salle University.
[*Corresponding author] Consolacion Y. Ragasa: Prof., Tel/Fax:
632-5360230, E-mail: consolacion.ragasa@dlsu.edu.ph
These authors have no any conflict of interest to declare.
type polysaccharides, GOA1 and GOA2 from the aerial parts
of G. oppositifolius exhibited potent dose-dependent com-
plement fixating activities, and induced chemotaxis of ma-
crophages, T cells and NK cells[3]. GOA1 was also reported
to induce proliferation of B cells and the secretion of IL-1
by macrophages, in addition to a marked increase of mRNA
for IFN- in NK cells[6]. Two new triterpenoid saponins, gli-
nosides A and B were isolated from the aerial parts of G. op-
positifolius. Fractions of the extract exhibited better an-
tiplasmodial activity than pure glinoside A[7].
We report herein the isolation and structure elucidation
of a new triterpene (1), along with spinasterol (2), squalene (3)
and lutein (4) (Fig. 1) from the dichloromethane extract of
the air-dried leaves of G. oppositifolius.
2 Experimental
2.1 General
Optical rotations were taken with a Jasco DIP-370 digital
polarimeter. IR spectra were recorded on a Perkin-Elmer
1600 Fourier Transform IR spectrometer. UV spectra were
recorded on a U-2000 Hitachi UV-vis spectrometer. HREIMS
was obtained on a Finnigan/Thermo Quest MAT 95 XL spec-
trometer. NMR spectra were recorded on a Varian VNMRS
spectrometer in CDCl3 at 600 MHz for 1H NMR and 150
MHz for 13C NMR spectra. Column chromatography was
performed with silica gel 60 (70-230 μm), while the TLC was
performed with plastic backed plates coated with silica gel
F254. The plates were visualized by spraying with vanillin-
H2SO4, followed by warming.
Consolacion Y. Ragasa, et al. /Chinese Journal of Natural Medicines 2012, 10(4): 284286
2012 年 7 月 第 10 卷 第 4 期 Chin J Nat Med July 2012 Vol. 10 No. 4 285


Fig. 1 Chemical structures of compounds 1-4

2.2 Plant material
The leaves of Glinus oppositifolius Linn. were collected
from southwestern Mindoro, Philippines in January 2010.
The plant, locally known as papait, grows in rice fields at
fallow periods and is sold in local market as vegetable. Speci-
mens of the plant were collected and authenticated by one of the
authors (E.H.M.). A voucher specimen No. 894 was deposited
at the Biology Department, De La Salle University – Manila.
2.3 Extraction and isolation
The air-dried leaves of Glinus oppositifolius (506.4 g)
were ground in an osterizer, soaked in dichloromethane for
three days, and then filtered. The filtrate was concentrated
under vacuum to afford the crude extract (15.1 g), which was
fractionated by silica gel chromatography using increasing
proportions of acetone in dichloromethane (10% increment)
as eluents. Fractions were collected and monitored by thin-
layer chromatography (TLC). Fractions with spots of the
same Rf values were combined and rechromatographed in
appropriate solvent systems until TLC pure isolates were
obtained.
The DCM fraction from the chromatography of the crude
extract was rechromatographed (5 ×) in petroleum ether to
afford 3 (12 mg). The 10% to 20% acetone in dichloro-
methane fractions were rechromatographed (6 ×) in 15%
ethyl acetate in petroleum ether to afford 2 (18 mg). The 30%
acetone in dichloromethane fraction was rechromatographed
(4 ×) in 0.5 : 0.5 : 9 by volume diethyl ether : acetonitrile :
DCM to afford 4 (8 mg) after washing with diethyl ether. The
40% to 50% acetone in dichloromethane fractions were re-
chromatographed (6 ×) in 0.5 : 0.5 : 9 by volume diethyl
ether : acetonitrile : DCM to afford 1 (10 mg).
3 Structural Identification
Oppositifolone (1) Colorless solid, mp 285−287 C;
25
D]α[ +4.0 (c = 0.40, CHCl3); IR neat: max = 3 500, 3 415
(OH), 1 687 (C=O), 1 256, 1 091, 1 030, 1 914 (C-O), 2 924,
2 853, 1 380 cm1; 1H NMR (600 MHz, CDCl3):  1.42, 1.94
(H2-1), 2.40, 2.50 (H2-2), 1.30 (H-5), 1.52, 1.54 (H2-6), 1.48
(H2-7), 1.38 (H-9), 1.38, 1.85 (H2-11), 3.91 (H-12, td, J = 4.8,
10.2 Hz), 1.40 (H-13), 1.34, 1.72 (H2-15), 3.68 (H-16, dt, J =
4.8, 11.4 Hz), 1.76 (H-17, d, J = 11.4 Hz ), 1.28, 2.02 (H2-19),
1.85, 2.06 (H2-20), 1.06 (H3-23, s), 1.01 (H3-24, s), 0.94
(H3-25, s), 1.05 (H3-26, s) 0.99 (H3-27, s), 1.02 (H3-28, s),
1.41 (H3-29, s), 2.22 (H3-30, s); 13C NMR (150 MHz,
CDCl3):  39.4 (C-1), 34.0 (C-2), 217.5 (C-3), 47.3 (C-4),
54.8 (C-5), 19.7 (C-6), 32.4 (C-7), 45.5 (C-8), 48.0 (C-9),
36.6 (C-10), 32.8 (C-11), 69.5 (C-12), 55.1 (C-13), 41.4
(C-14), 45.1 (C-15), 65.7 (C-16), 59.1 (C-17), 46.3 (C-18),
44.1 (C-19), 35.8 (C-20), 54.4 (C-21), 217.0 (C-22), 26.5
(C-23), 21.1 (C-24), 15.6 (C-25), 16.6 (C-26), 18.6 (C-27),
17.2 (C-28), 21.06 (C-29), 25.9 (C-30); HRMS m/z 472.3553
[M+] (C30H48O4).
Spinasterol (2) 13C NMR (150 MHz, CDCl3):  37.1
(C-1), 31.5 (C-2), 71.1 (C-3), 38.0 (C-4), 40.2 (C-5), 29.6
(C-6), 117.4 (C-7), 139.6 (C-8), 49.4 (C-9), 34.2 (C-10), 21.5
(C-11), 39.4 (C-12), 43.3 (C-13), 55.1 (C-14), 23.0 (C-15),
28.5 (C-16), 55.9 (C-17), 12.0 (C-18), 13.0 (C-19), 40.8
(C-20), 21.4 (C-21), 138.2 (C-22), 129.4 (C-23), 51.2 (C-24),
31.9 (C-25), 21.1 (C-26), 19.0 (C-27), 25.4 (C-28), 12.2
(C-29).
Squalene (3) 13C NMR (150 MHz, CDCl3):  25.7
(C-1), 131.3 (C-2), 124.3 (C-3), 26.7 (C-4), 39.7 (C-5), 134.9
(C-6), 124.3 (C-7), 26.7 (C-8), 39.7 (C-9), 134.9 (C-10),
124.3 (C-11), 28.3 (C-12), 17.7(C-2), 16.0 (C-6), 16.0
(C-10).
Lutein (4) 13C NMR (150 MHz, CDCl3): 37.1 (C-1),
48.4 (C-2), 65.1 (C-3), 42.5 (C-4), 126.2 (C-5), 138.0 (C-6),
125.6 (C-7), 138.5 (C-8), 135.7 (C-9), 131.3 (C-10), 124.9
(C-11), 137.6 (C-12), 136.4 (C-13), 132.6 (C-14), 130.1
(C-15), 28.7 (C-16), 30.3 (C-17), 21.6 (C-18), 12.7 (C-19 and
C-20), 34.0 (C-1), 44.6 (C-2), 65.9 (C-3), 124.5 (C-4),
137.7 (C-5), 55.0 (C-6), 128.7 (C-7), 130.8 (C-8),
135.1(C-9), 137.6 (C-10), 124.8 (C-11), 137.7 (C-12),
136.5 (C-13), 132.6 (C-14), 130.1 (C-15), 24.3 (C-16),
29.5 (C-17), 22.9 (C-18), 13.1 (C-19), 12.8 (C-20).
4 Results and Discussion
The dichloromethane extract of the air-dried leaves of
Glinus oppositifolius afforded 1 by silica gel chromatography.
The structure of 1 was elucidated by extensive 1D and 2D
NMR spectroscopy as follows.
1H NMR spectrum of 1 gave resonances for eight methyl
groups at  0.94 (s), 0.99 (s), 1.01 (s), 1.02 (s), 1.05 (s), 1.06
(s), 1.41 (s) and 2.22 (s) and two oxymethines at  3.68 (H-16,
dt, J = 4.8, 11.4 Hz) and 3.91 (H-12, td, J = 4.8, 10.2 Hz).
Broad hydroxyl proton resonances were detected at  1.56
and 2.70. 13C NMR spectrum of 1 gave resonances for thirty
carbons with the following functionalities: two ketone car-
bonyls at  217.0 and 217.5, two oxymethine carbons at 
65.7 and 69.5, eight methyls, eight methylenes, four methines
Consolacion Y. Ragasa, et al. /Chinese Journal of Natural Medicines 2012, 10(4): 284286
286 Chin J Nat Med July 2012 Vol. 10 No. 4 2012 年 7 月 第 10 卷 第 4 期

and six quaternary carbons. These data suggested a triterpene
with two hydroxyl and two ketone functionalities. This was
supported by the HREI-MS of 1 which gave a molecular ion
of m/z 472.355 3 [M+], corresponding to a molecular formula
of C30H48O4. The molecular formula indicated an index of
hydrogen deficiency of seven. With the two carbonyls de-
duced from the 13C NMR spectrum, the compound is a pen-
tacyclic triterpene.
Five isolated spin systems (Fig. 2) were deduced from
the COSY spectrum of 1 as follows: methylene protons  to a
carbonyl coupled to another set of methylene protons
(H2-2/H2-1); a methine proton coupled to methylene protons
which were in turn coupled to another set methylene protons
(H-5/H2-6/H2-7); a methine proton coupled to methylene
protons which were in turn coupled to an oxymethine proton
which was further coupled to a methine proton (H-9/H2-11/
H-12/H-13); methylene protons coupled to an oxymethine
proton which was in turn coupled to a methine proton (H2-
15/H-16/H-17); and coupled methylene protons (H2-19/ H2-20).

Fig. 2 1H-1H COSY and 1H-13C long-range correlations of 1
Protons attached to carbons were assigned (see
experimental) from HSQC 2D NMR data and the structure of
1 was elucidated by analysis of the HMBC 2D NMR data:
key HMBC correlations are shown in Fig. 2. Thus, a
hydroxyl was attached to C-12 on the basis of long-range
correlations between the proton at  3.91 (H-12) and C-11,
C-13, C-14 and C-18. The second hydroxyl was attached to
C-16 since long-range correlations were obtained between
the proton at  3.68 (C-16) and C-14, C-15, C-17, C-18 and
C-21. The first carbonyl was assigned to C-3 based on
long-range correlations with the protons at H2-1, H2-2, H-5,
H3-23 and H3-24. The second carbonyl was assigned to C-22
due to long-range correlations with H-17, H2-20, H3-29 and
H3-30. Long-range correlations were also observed between
the methine proton at H-5 and the methyl carbons at C-23,
C-24 and C-25; the methine proton at H-9 and the methyl
carbons at C-25 and C-26; the methine proton at H-13 and
the methyl carbons at C-27 and C-28; and the methine proton
at H-17 and the methyl carbons at C-28 and C-29. All
long-range correlations are consistent with the structure of 1.
The relative configuration of 1 (Fig. 3) was deduced
from NOESY as follows. The methyl singlet (H3-23) was
close in space to the methine proton (H-5), which was in turn
close to another methine proton (H-9). This proton was close
to the oxymethine proton (H-12) and the methyl singlet
(H3-27). The oxymethine proton (H-12) correlated with the
methyl singlets (H3-27 and H3-28). The methyl singlet (H3-27)
showed correlation with the methine proton (H-16) which
also correlated with H3-29 and H3-28. These correlations
indicate that they are on the same face of the molecule. On
the opposite face of 1, the following correlations were ob-
served. The methyl singlet (H3-24) was close in space to the
methyl singlet (H3-25), which was close to another methyl
singlet (H3-26), which was in turn close to methine proton
(H-13), which was finally close to another methine proton
(H-17). All NOESY correlations were consistent with the
relative configuration of 1 shown in Fig. 3. The trivial name
oppositifolone is suggested for 1.

Fig. 3 NOESY correlations of 1
Literature search revealed that triterpenoid saponins,
spergulin A and B with the same triterpene skeleton and
relative configuration as 1 have been isolated from the aerial
part of Mollugo spergula[8].
Compounds 2−4 were identified by comparison of their
13C NMR data with those found in the literature for
spinasterol[9], squalene[10], and lutein[11], respectively.
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