A new 3,4-seco-cycloartane from the leaves of Hopea odorata Roxb.

Article abstract of DOI:10.1080/14786419.2015.1007975

A new 3,4-seco-cycloartane, identified as (24R,25S)-dihydroxy-26-O-nonadecylcarbonyloxy-3,4-secocycloarta-4(28)-en-3-oic acid (1), has been isolated from the leaves of Hopea odorata Roxb. (Dipterocarpaceae), together with the rare 3,4-seco-cycloart-4(28),24-diene-3,26-dioic acid (2 or abiesatrine J) and six other known compounds (3-8). Their structures were elucidated on the basis of both chemical and spectroscopic methods.

Full text of DOI:10.1080/14786419.2015.1007975

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A new 3,4-seco-cycloartane from the
leaves of Hopea odorata Roxb.
Malai Satiraphana, Quoc Dang Thaib, Uthai Sotanaphunc, Chavalit
Sittisombutc, Sylvie Michelb & Xavier Cachetb
a Department of Pharmaceutical Chemistry, Faculty of Pharmacy,
Silpakorn University, Sanamchandra Campus, Nakorn-Pathom
73000, Thailand
b Laboratoire de Pharmacognosie, UMR 8638 COMETE CNRS,
Faculté des Sciences Pharmaceutiques et Biologiques, Université
Paris Descartes, Sorbonne Paris Cité, 4 avenue de l'Observatoire,
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75006 Paris, France
c Department of Pharmacognosy, Faculty of Pharmacy, Silpakorn
University, Sanamchandra Campus, Nakorn-Pathom 73000,
Thailand
Published online: 10 Feb 2015.
To cite this article: Malai Satiraphan, Quoc Dang Thai, Uthai Sotanaphun, Chavalit Sittisombut,
Sylvie Michel & Xavier Cachet (2015): A new 3,4-seco-cycloartane from the leaves of
Hopea odorata Roxb., Natural Product Research: Formerly Natural Product Letters, DOI:
10.1080/14786419.2015.1007975
To link to this article: http://dx.doi.org/10.1080/14786419.2015.1007975
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Natural Product Research, 2015
http://dx.doi.org/10.1080/14786419.2015.1007975
A new 3,4-seco-cycloartane from the leaves of Hopea odorata Roxb.
Malai Satiraphana, Quoc Dang Thaib, Uthai Sotanaphunc, Chavalit Sittisombutc, Sylvie Michelb
and Xavier Cachetb*
aDepartment of Pharmaceutical Chemistry, Faculty of Pharmacy, Silpakorn University, Sanamchandra
Campus, Nakorn-Pathom 73000, Thailand; bLaboratoire de Pharmacognosie, UMR 8638 COMETE
´
CNRS, Faculte des Sciences Pharmaceutiques et Biologiques, Universite Paris Descartes, Sorbonne Paris
Cite, 4 avenue de l’Observatoire, 75006 Paris, France; Department of Pharmacognosy, Faculty of
´
c
´
Pharmacy, Silpakorn University, Sanamchandra Campus, Nakorn-Pathom 73000, Thailand
(Received 7 November 2014; final version received 10 January 2015)
A new 3,4-seco-cycloartane, identified as (24R,25S)-dihydroxy-26-O-nonadecylcar-
bonyloxy-3,4-secocycloarta-4(28)-en-3-oic acid (1), has been isolated from the leaves
of Hopea odorata Roxb. (Dipterocarpaceae), together with the rare 3,4-seco-cycloart-4
(28),24-diene-3,26-dioic acid (2 or abiesatrine J) and six other known compounds (3–
8). Their structures were elucidated on the basis of both chemical and spectroscopic
methods.
Keywords: 3; 4-secocycloartane; triterpenoid; Hopea odorata; Dipterocarpaceae
1. Introduction
In traditional Thai medicine, the bark and, to a lower extent, the leaves of Hopea odorata Roxb.
(Family: Dipterocarpaceae), commonly called ‘Ta-khian-thawng’ in Thai, are used as anti-
inflammatory remedies for the treatment of various diseases such as paralysis, haemorrhoids,
toothache and gum inflammation (Shiva & Jantan 1998). Due to high tannin content, these plant
parts are also used in several Southeast Asian countries for leather tanning (Seok Yang et al.
2013). Phytochemical analyses of this plant also revealed the presence of bioactive resveratrol
oligomers in the stem bark (Nguyen et al. 2007; Atun et al. 2008), and flavon-3-ols in the leaves
(Joshi 2003). In a previous paper, we have reported the isolation of eight lupane triterpenes,
along with common b-sitosterol and b-caryophyllene oxide, from a n-hexane extract of the
leaves of H. odorata (Satiraphan et al. 2012). As a continuation of our investigation, we describe
*Corresponding author. Email: xavier.cachet@parisdescartes.fr
q 2015 Taylor & Francis

2
M. Satiraphan et al.
herein the isolation and structural elucidation of a new 3,4-secocycloartane triterpene (1),
together with seven known compounds (2–8).
2. Results and discussion
Further purification of the n-hexane extract of the leaves of H. odorata by repeated silica gel and/
or Sephadex LH-20 columns allowed the isolation of the new 3,4-secocycloartane 1, together
with five triterpenes and sterols (i.e. abiesatrine J or 3,4-seco-cycloart-4(28),24-diene-3,26-dioic
acid (2) (Yang et al. 2010), mangiferonic acid (3) (Zhang et al. 2003), friedelin (4) (Akihisa et al.
1992), epifriedelanol (5) (Salazar et al. 2000) and b-amyrine (6) (Mahato & Kundu 1994)), as
well as two tocopherol trimers IVa (7) and IVb (8) (Row et al. 2007) (Figure 1). Structures of
known compounds were determined by comparison of their spectral data with those previously
reported in the literature.
Compound 1 was obtained as a colourless amorphous solid. Its molecular formula was
established as C50H88O6, corresponding to seven degrees of unsaturation, on the basis of the high
resolution (HR)-electrospray ionisation (ESI)-MS analysis which showed an adduct ion
[M þ Na]þ at m/z 807.6495 (Calcd 807.6479). The shift of 3 uma from [MH þ Na]þ at m/z 808
using CH2Cl2/CH3OH as solvent for dissolution of the sample to [MD þ Na]þ at m/z 811 using
CH2Cl2/CD3OD, suggested the presence of three exchangeable protons in the molecule. The IR
spectrum of 1 displayed absorption bands at 3444 and 1712 cm21 that implied the existence of
hydroxyl and carbonyl groups. Finally, the presence of a carboxylic group was supported by the
methylation of 1 in gentle conditions, which quantitatively affords the corresponding
monomethyl ester 1a, characterised by both the appearance of a single methoxyl signal at dH
3.65 in its 1H NMR spectrum, and the existence of a pseudo-molecular ion peak at m/z 822 in the
ESI mass spectrum. A preliminary analysis of the 1H and 13C NMR spectra of 1 revealed that the
compound was a saturated fatty acid ester derivative. Typical signals indicative of such moiety
included an intense signal at dH 1.25 ((CH2) n), and a broad triplet at 2.37 (2H, J ¼ 7.4 Hz, H-20)
1
in the H NMR spectrum, as well as signals at dC 174.3 (C-10), 34.3 (C-20) and overlapping
signals from dC 29.2 to 29.6 ((CH2) n) in the 13C NMR spectrum. Mild alkaline saponification of
the methyl ester 1a yielded a fatty acid which was identified as arachidic acid (C20H40O2) by
Figure 1. Structures of compounds 1–8.

Natural Product Research
3
ESI-MS analysis (m/z 311 [M 2 H]2), as well as an alcohol (1b), which was found to have, as
expected, a molecular formula of C30H50O5 as determined by HR-ESI-MS analysis (m/z
513.3572 [M þ Na]þ).The position of the ester linkage will be discussed elsewhere in the text.
1
Apart from the signals due to the fatty acid moiety, the H NMR spectrum of 1 also displayed
two doublets at dH 0.42 (1H, J ¼ 4.0 Hz) and 0.73 (1H, J ¼ 4.0 Hz) and two broad singlets,
integrating each for one proton at dH 4.74 and 4.84, typical of a cyclopropane ring and a terminal
alkene, respectively. These data suggested that 1 was a 3,4-seco-cycloartane type triterpene.
Furthermore, comparison of the 13C NMR spectrum of 1 with those of abiesatrine J (Yang et al.
2010) 3 (isolated in the present study) and other structurally related 3,4-seco-cycloartanes (e.g.
gardenoin H, coccinetane A, sootepin E (Sy & Brown 1999; Nuanyai et al. 2009, 2011)) showed
that carbon resonances from C-1 to C-21 were almost superimposable and that these compounds
differ from one another only in the nature of their eight carbon side chain, corresponding to the
formula C28H55O4 in the case of 1. The side chain therefore bears the ester linkage with arachidic
acid. The 13C signals of the side chain part (C20–C27) were sorted by HSQC edited and
consisted of one tertiary methyl at dC 20.7, one secondary methyl at dC 18.2 (assigned to C-21),
three methylenes at dC 27.6, 33.3 and 68.4 (one oxy-methylene carbon), two methines at dC 35.9
(assigned to C-20) and 76.4 (one oxy-methine carbon) and one oxygen bearing quaternary
carbon at dC 73.9 (Supplementary Table S1 – online only). These data, in combination with
hydrogen-deuterium exchange ESI-MS experiment, suggested the presence at the side chain of
two hydroxyls besides the ester group, inasmuch as one of the three exchangeable signals
corresponded to the carboxyl group at C-2. In the HSQC edited spectrum, the oxy-methine
carbon resonance at dC 76.4 was correlated with the proton signal at dH 3.43 (1H, br d,
J ¼ 8.9 Hz), and the oxy-methylene carbon signal at dC 68.4 was correlated to the more
deshielded proton signals at dH 4.03 (1H, br d, J ¼ 11.5 Hz) and 4.27 (1H, br d, J ¼ 11.5 Hz)
suggesting that the position was esterified. This was confirmed by the existence of long-range
correlations (HMBC) between the latter methylene proton signals and the ester carbonyl carbon
at dC 174.3 (Supplementary Figure S1 – online only). Additional long-range correlations were
also observed between these two protons and the quaternary carbon at dC 73.9, and the tertiary
methyl at dC 20.7, while only the signal at dH 4.03 was correlated with the methine carbon at dC
76.4. Furthermore, long-range correlations were observed between the singlet at dH 1.19 (3H),
attributed to the tertiary methyl according to the HSQC edited spectrum, and oxygen-bearing
carbons at dC 68.4, 73.9 and 76.4. All together, these data suggested that the oxygen-bearing
carbons of the side chain were contiguous and also allowed the location of the tertiary hydroxyl
at C-25, that of the secondary alcohol at C-24 and finally that of the ester moiety at C-26. The
remaining side chain methylene carbon signals at dC 27.6 and 33.3 were assigned to C-23 and C-
22, respectively. The proposed structure for the side chain of 1 and the corresponding NMR data
assignments were also supported from HSQC and HMBC experiments on the methyl ester 1a
(Supplementary Figure S2 – online only).
The relative stereochemistry of 1 was investigated by a ROESY experiment performed on 1a
(Supplementary Figure S3 – online only).
The existence of NOE correlations from H-5 to H-1b and H-6a on one hand, and from CH3-
30 to H-17 and H-11a on the other hand, indicated an a-position of these protons, whereas
NOESY cross-peaks of H-8 with H-19b/H-6b/CH3-18, CH3-18 with H-20 and CH3-21 with H-
12 suggested that H-8, CH3-18 and H-20 are in a b-orientation. Furthermore, the b-orientation of
the cyclopropane ring at C-9 and C-10 was supported by NOE correlations of H-19b with H-6b/
H-8/CH3-29, and H-19a with H-11b. The observed NOE correlations were thus in good
agreement with the relative stereochemistry at C-5, C-8, C-9, C-10, C-17 and C-20, long
established for the 3,4-seco-cycloartane core.
Finally, the absolute configurations at both C-24 and C-25 were determined to be 24R and
25S by comparison of the readily recognisable signals of C-24, C-25 and C-26 measured for triol

4
M. Satiraphan et al.
1c (i.e. dC 78.6, 74.1 and 67.6, respectively) with those of the corresponding carbons reported in
literature for the four synthetic ganodermontriol stereoisomeric triols at C-24 and C-25
(Kennedy et al. 2011). Thus, these chemical shift values were found remarkably similar to those
reported for the (24R,25S) isomer (i.e. 78.5, 73.9 and 67.6, respectively vs 79.3/74.0/67.6 for
isomer (24S,25R); 77.2/74.1/69.3 for isomer (24S,25S) and 76.2/74.1/69.4 for isomer
(24R,25R)). Moreover, the chemical shifts of H-24, H-26a and H-26b of 1c closely matched
those of the (24R,25S) ganodermontriol isomer. Thus, the structure of 1 was established as
depicted in Figure 1.
3. Experimental
3.1. General experimental procedures
Melting points were determined using a LEICA VM microscope equipped with a heating stage
and are uncorrected. Optical rotations were measured using a Perkin-Elmer Model 341
polarimeter and IR spectra were obtained with a Spectrum 65 ATR-FT-IR (Perkin Elmer,
Courtaboeuf, France). 1D NMR spectra were recorded at 300 MHz (1H) and at 75 (13C) with a
AC 300 spectrometer (Bruker, Wissembourg, France). ROESY experiments were recorded at
500 MHz on a Avance 500 BRUKER spectrometer (mixing time: 300 ms); other 2D experiments
were recorded at 400 MHz on a Avance 400 BRUKER apparatus. Chemical shifts (d) are given
in ppm relative to solvent peaks as internal standards (d: CDCl3: 7.27 ppm (1H), 77.0 ppm (13C);
coupling constants are given in Hertz (Hz, J). Mass spectra were measured with a ZQ 2000 ESI
mass spectrometer (Waters MS Technologies, Manchester, UK) and HR-ESI-MS experiments
were recorded on a time-of-flight LCT Premier spectrometer (Waters MS Technologies,
Manchester, UK). GC/MS-EI analyses were carried out with a GC chromatograph 6890 GC
(Hewlett–Packard, Wilmington, DE) coupled to a 5975 quadrupole MS. Preparative MPLC was
performed on silica gel (SDS 60 A C.C. 20–45 mM), on a Bu¨chi apparatus equipped with Bu¨chi
fraction collector C-660, Bu¨chi pump manager C-615 and Bu¨chi pump module C-601. Column
chromatography was carried out with silica gel (SDS 60 A C.C. 35–70 mM). Sephadex LH-20
was purchased from Sigma-Aldrich. Fractions were monitored by TLC using precoated Merck
Kieselgel 60 F254 silica gel plates, and spots were visualised by spraying the plates with
sulphuric vanillin reagent followed by heating. Cyclohexane, dichloromethane and ethyl acetate
were distilled prior to use.
3.2. Plant material
The leaves of H. odorata Roxb. were collected in September 2004 from the province of Chiang
Mai (Maerim District) in the North of Thailand, and the plant was identified by Dr Chavalit
Sittisombut. A voucher specimen (PC0704) was deposited at the herbarium of the Department of
Pharmacognosy, Silpakorn University, Nakhon Pathom, Thailand.
3.3. Extraction and isolation
The dried and powdered leaves of H. odorata (1,08 kg) were extracted by maceration in n-
hexane (3 L £ 3, 48 h), and the combined extracts were concentrated in vacuo to dryness to
afford a residue of 19.5 g. A first portion of this residue (2.03 g) was flash chromatographed on
silica gel using a gradient of CH2Cl2 in cyclohexane (0:100 to 95:5), and then MeOH as
successive eluents, to give 19 fractions (A01–A19). Fraction A06 was subjected to column
chromatography, using cyclohexane–EtOAc (10:1) as eluent to afford 8 (9.4 mg). Prior to
evaporation of the solvent, compound 4 (8.0 mg) directly crystallised on standing from fraction
A07. Fraction A10 was purified over silica gel CC, using cyclohexane–EtOAc (6:1) as eluent, to

Natural Product Research
5
afford 6 (20 mg) as colourless crystals. Fraction A17 was fractionated on a silica gel column,
eluted with cyclohexane–EtOAc (10:1) to give an additional amount of 4 (3 mg) and 5 (3 mg).
A larger portion of the n-hexane residue (10.35 g) was purified by MPLC on silica gel, using the
same gradient solvent system mentioned earlier for the fractionation of the first extract portion,
to afford 24 fractions designated as B01–B24. Fraction B15 (404.9 mg) was chromatographed on
a silica gel column using cyclohexane–EtOAc (80:1) as eluent, to give a subfraction B015 which
was further purified on a column of Sephadex LH-20 eluted with CHCl3–MeOH (3:1) to afford
7 as a pale yellow oil (9.7 mg). Fraction B23 (7.28 g) was subjected to MPLC on silica gel using a
gradient of00EtOAc in CH2Cl2 (0:100 to 75:25) as eluent, to afford 42 subfractions (B0001 –B4002).
Fraction B07 (176.9 mg) was purified on a00silica gel column, eluted with CH2Cl2 to give an
additional amount of 6 (45 mg). Fraction B35 (129.2 mg) was chromatographed on a silica gel
00
column, eluted with cyclohexane–EtOAc (5:0.7), to give 3 (3.0 mg). Fraction B (220.0 mg)
40
was purified on silica gel CC, using a gradient of EtOAc in cyclohexane (1:4 to 1:3) as eluent, to
yield compound 1 (54.5 m0g0 ) as a colourless oi0l0. Under the same chromatographic conditions,
purification of fractions B41 (228.7 mg) and B42 (280.0 mg) led to the isolation of additional
00
amounts of 1 (10.0 and 30.0 mg, respectively). Purification of fraction B also afforded
compound 2 as a colourless solid (5.0 mg).
(24R,25S)-Dihydroxy-26-O-nonadecylcarbonyloxy-3,4-secocycloarta-4(28)-en-3-oic acid
42
(1): colourless amorphous solid; ½aꢀD þ 26.3 (c 0.19, CHCl3); IR (film) nmax cm21: 3445,
20
1
3500–2500 (br), 2924, 2853, 1721, 1713, 1456, 1376, 1176; H-NMR (CDCl3): d 0.42 (1H,
d, J ¼ 4.0 Hz, H-19a), 0.73 (1H, d, J ¼ 4.0 Hz, H-19b), 0.88 (6H, m, 21-CH3, v1-CH3), 0.94
(3H, s, 30-CH3), 0.97 (3H, s, 18-CH3), 1.08 (1H, m, H-6b), 1.10 (1H, m, H-7a), 1.19 (3H, s,
27-CH3), 1.25 (33H, m, (CH02)16, H-11b), 1.29 (1H, m, H-16b), 1.30 (3H, m, H-15, H-22a),
1.31 (1H, m, H-7b), 1.39 (1H, m, H-1a), 1.41 (1H, m, H-23a), 1.43 (1H, m, H-20), 1.47 (1H,
m, H-23b), 1.49 (1H, m, H-22b), 1.53 (1H, m, H-6a), 1.57 (1H, m, H-8), 1.60 (1H, m, H-17),
1.63 (2H, m, H-30), 1.66 (2H, m, H-12), 1.69 (3H, s, 29-CH3), 1.93 (1H, m, H-16a), 2.07
(1H, m, H-1b), 2.11 (1H, m, H-11a), 2.31 (1H, m, H-2a), 2.37 (2H, br t, J ¼ 7.4 Hz, H-20),
2.43 (1H, m, H-5), 2.55 (1H, ddd, J ¼ 15.6, 11.7 and 5.7 Hz, H-2b), 3.43 (1H, br d,
J ¼ 8.9 Hz, H-24), 4.03 (1H, br d, J ¼ 11.5 Hz, H-26a), 4.27 (1H, br d, J ¼ 11.5 Hz, H-26b),
4.74 (1H, br s, H-28a), 4.82 (1H, br s, H-28b). 13C-NMR (CDCl3): 14.1 (C-v1), 18.1 (C-18),
18.2 (C-21), 19.3 (C-30), 19.7 (C-29), 20.7 (C-27), 21.3 (C-9), 22.7 (C-v2), 25.0 (C-30, C-7),
26.9 (C-10, C-11), 27.6 (C-23), 27.7 (C-6), 28.2 (C-16), 28.8 (C-1), 29.2-29.6 (overlap,
(CH2)0 14), 30.0 (C-19), 31.1 (C-2), 31.9 (C-v3), 33.0 (C-12), 33.3 (C-22), 34.3 (C-20), 35.6
(C-15), 35.9 (C-20), 45.1 (C-13), 45.9 (C-5), 47.7 (C-8), 49.0 (C-14), 52.3 (C-17), 68.4 (C-
26), 73.9 (C-25), 76.4 (C-24), 111.6 (C-28), 149.4 (C-4), 174.3 (C-10), 178.2 (C-3); ESI-MS:
m/z 808 [M þ Na]þ; ESI-MS (H/D exchange MS by dissolution of the sample in a mixture of
CH2Cl2 and CD3OD) m/z: 811 [M þ 3 þ Na]þ; HR-ESI-MS: m/z 807.6495 [M þ Na]þ
(Calcd for C50H88O6Na: 807.6479).
3.4. Methylation of 1
To a solution of acid 1 (47 mg, 0.06 mmol), anh. DMF (3.5 mL), NaHCO3 (17 mg, 0.2 mmol) and
CH3I (12.5 mL, 0.2 mmol) were successively added and the reaction was magnetically stirred
overnight at room temperature. After completion of the reaction, monitored by TLC (solvent:
cyclohexane–EtOAc (2:1)), 10 mL of EtOAc and 5 mL of distilled water were added. After
separation of the organic phase, the remaining aqueous phase was twice extracted with EtOAc
(10 mL). The combined organic phases were twice washed with distilled water (5 mL), and then
dried over anh. MgSO4, filtered and concentrated under reduced pressure. The residue (30 mg)
was purified by CC on silica gel, using cyclohexane–EtOAc (5:1) as eluent, to afford 1a (46 mg,
quantitative yield).

6
M. Satiraphan et al.
Methyl (24R,25S)-dihydroxy-26-O-nonadecylcarbonyloxy-3,4-secocycloarta-4(28)-en-3-
oate (1a): colourless amorphous solid; ½aꢀD þ 74.0 (c ¼ 0.10, CHCl3); IR (film) nmax cm21
:
20
3500, 2924, 1740, 1456, 1376; 1H-NMR (CDCl3):d 0.41 (1H, d, J ¼ 4.1 Hz, H-19a), 0.73 (1H,
d, J ¼ 4.1 Hz, H-19b), 0.88 (6H, m, 21-CH3, v1-CH3), 0.94 (3H, s, 30-CH3), 0.97 (3H, s, 18-
CH3), 1.09 (1H, m, H-6b), 1.10 (1H, m, H-7a), 1.20 (3H, s, 27-CH3), 1.25 (33H, m, (CH02)16,
H-11b), 1.29 (1H, m, H-16b), 1.30 (2H, m, H-15), 1.31 (2H, m, H-7b, H-22a), 1.38 (1H, m, H-
1a), 1.41 (2H, m, H-20, H-23a), 1.46 (1H, m, H-23b), 1.48 (1H, m, H-22b), 1.53 (1H, m, H-
6a), 1.57 (1H, m, H-8), 1.59 (1H, m, H-17), 1.63 (2H, m, H-30), 1.66 (2H, m, H-12), 1.69 (3H,
s, 29-CH3), 1.90 (1H, m, H-16a), 2.05 (1H, m, H-1b), 2.10 (1H, m, H-11a), 2.27 (1H, ddd,
J ¼ 15.5, 12.0 and 4.0 Hz, H-2a), 2.38 (2H, br t, J ¼ 7.5 Hz, H-20), 2.43 (1H, m, H-5), 2.51
(1H, ddd, J ¼ 15.5, 12.1 and 5.7 Hz, H-2b), 3.42 (1H, br d, J ¼ 8.9 Hz, H-24), 3.65 (3H, s,
CH3-O), 4.04 (1H, br d, J ¼ 11.4 Hz, H-26a), 4.28 (1H, br d, J ¼ 11.4 Hz, H-26b), 4.74 (1H, br
s, H-28a), 4.81 (1H, br s, H-28b). 13C-NMR (CDCl3): 14.2 (C-v1), 18.1 (C-18), 18.2 (C-21),
19.3 (C-30), 19.8 (C-29), 20.7 (C-27), 21.3 (C-9), 22.7 (C-v2), 25.0 (C-30, C-7), 26.9 (C-11),
27.0 (C-10), 27.6 (C-23), 27.8 (C-6), 28.2 (C-16), 29.0 (C-1), 29.2-29.6 (overlap, (CH2)0 14),
30.0 (C-19), 31.4 (C-2), 31.9 (C-v3), 33.0 (C-12), 33.2 (C-22), 34.3 (C-20), 35.6 (C-15), 35.8
(C-20), 45.1 (C-13), 45.8 (C-5), 47.7 (C-8), 49.0 (C-14), 51.4 (C H3-O), 52.3 (C-17), 68.4 (C-
26), 73.9 (C-25), 76.4 (C-24), 111.5 (C-28), 149.5 (C-4), 174.3 (C-10), 174.5 (C-3); ESI-MS:
m/z 822 [M þ Na]þ; HR-ESI-MS: m/z 821.6651 [M þ Na]þ (Calcd for C51H90O6Na
821.6635).
3.5. Saponification of 1a
To a stirred solution of 1a (10.4 mg, 0.013 mmol) in a 1:2 mixture of THF–H2O (3 mL),
LiOH.H2O (1.2 mg, 0.029 mmol) was added at room temperature. Then, the reaction mixture
was heated at 508C for 3 h (TLC monitoring, with cyclohexane–EtOAc (2:1) as eluent), and
then concentrated in vacuo to dryness. The residue was taken up in 3 mL of AcOH–H2O
(3:1) and the resulting solution was extracted twice with 5 mL of CH2Cl2. The solvent was
evaporated under reduced pressure and the oily residue was partitioned between cyclohexane
(3 mL) and a 3:1 mixture of MeOH–H2O (3 mL). Both fractions were concentrated under
reduced pressure to dryness in order to obtain as colourless oils, eicosanoic acid (arachidic
acid, 3 mg) and 1b (6 mg), respectively. The identification of the fatty acid was confirmed by
mass spectrometry analysis (ESI-MS: m/z 311 [M 2 H]2, 623 [2M 2 H]2 (Calcd for
C20H40O2, 312)).
24R,25S,26-Trihydroxy-3,4-secocycloarta-4(28)-en-3-oic (1b):
25
A colourless oil;
½aꢀD þ 52.9 (c ¼ 0.35, CHCl3); IR (film) nmax cm21: 2927, 2867, 1715, 1454, 1443, 1260,
1020, 1010, 820; 1H-NMR (CDCl3): d 0.43 (1H, d, J ¼ 4.3 Hz, H-19a), 0.75 (1H, d, J ¼ 4.3 Hz,
H-19b), 0.90 (3H, d, J ¼ 5.9 Hz, 21-CH3), 0.95 (3H, s, 30-CH3), 0.99 (3H, s, 18-CH3), 1.10 (2H,
m, H-6b, H-7a), 1.12 (3H, s, 27-CH3), 1.25 (1H, H-11b), 1.29 (1H, m, H-16b), 1.31 (2H, m, H-
15), 1.33 (2H, m, H-7b, H-22a), 1.38 (1H, m, H-1a), 1.40 (1H, m, H-23a), 1.44 (1H, m, H-20),
1.47 (1H, m, H-23b), 1.53 (1H, m, H-22b), 1.55 (1H, m, H-6a), 1.58 (1H, m, H-8), 1.61 (1H, m,
H-17), 1.68 (2H, m, H-12), 1.70 (3H, s, 29-CH3), 1.94 (1H, m, H-16a), 2.06 (1H, m, H-1b), 2.11
(1H, m, H-11a), 2.30 (1H, m, H-2a), 2.45 (1H, m, H-5), 2.55 (1H, ddd, J ¼ 15.6, 11.5 and
5.5 Hz, H-2b), 3.50 (2H, m, H-24, H-26a), 3.86 (1H, br d, J ¼ 11.2 Hz, H-26b), 4.75 (1H, br s, H-
28a), 4.83 (1H, br s, H-28b). 13C-NMR (CDCl3): 18.2 (C-18, C-21), 19.3 (C-30), 19.7 (C-29),
21.1 (C-27), 21.3 (C-9), 25.0 (C-7), 26.9 (C-10, C-11), 27.7 (C-6), 28.2 (C-16), 28.7 (C-23), 28.8
(C-1), 30.0 (C-19), 31.3 (C-2), 33.0 (C-12), 33.3 (C-22), 35.7 (C-15), 36.0 (C-20), 45.1 (C-13),
45.9 (C-5), 47.8 (C-8), 49.0 (C-14), 52.5 (C-17), 67.6 (C-26), 74.1 (C-25), 78.6 (C-24), 111.6 (C-
28), 149.4 (C-4), 179.0 (C-3); HR-ESI-MS: m/z 513.3572 [M þ Na]þ (calcd for C30H50O5Na,
513.3556).

Natural Product Research
7
4. Conclusion
In conclusion, this paper reports the isolation and structural elucidation of the new 3,4-
secocycloartane 1, together with seven known compounds 2–8, from the leaves of H. odorata.
To the best of our knowledge, compounds 2–8 were isolated for the first time from H. odorata
Roxb., and to date, abiesatrine J (2) has been reported only from Abies georgei Orr. (Yang et al.
2010). In addition, the co-occurrence of 2 with its putative biogenetic precursor, namely the
cycloartane-type mangiferonic acid (3), should also be highlighted. This work also constitutes
the first report of a 3,4-seco-cycloartane triterpene possessing a trihydroxylated side chain at the
C-24, C-25 and C-26 positions. Furthermore, tarecilioside B, a cycloartane glycoside present in
leaves of Tarenna gracilipes, was until now the only representative of triterpenes isolated from
higher plants with such a side chain (Zhao et al. 2008).
Supplementary material
Table S1, Figures S1–S3 relating to this article, as well as original spectroscopic data of
compounds 1, 1a, 1b and 2–8 are available online.
Acknowledgements
The authors wish to thank Mrs P. Leproux of Paris Descartes University for the MS H/D exchange
experiments, as well as Dr Robert E. Minto of Indiana University-Purdue University for helpful discussions
concerning NMR data of ganodermanontriol stereoisomeric triols.
Funding
This work was supported the French Ministry of Foreign Affairs (Program in Higher Education and
Research, 2009–2010) [grant number 20589RK]; and the Faculty of Pharmacy, Silpakorn University.
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