New monoterpenoids from fruits of Gardenia jasminoides var. radicans

Article abstract of DOI:10.1002/hlca.201500063

One new lactone, cyclopentanepyrone A (1), and two new monoterpenoids, gardeterpenone A (2) and jasminoside V (3), were isolated from the fruits of Gardenia jasminoides var. radicans, along with four known monoterpenoids, 4-7, which were isolated from this plant for the first time. The structures of the isolates were elucidated by extensive spectroscopic studies, including UV, IR, 1D- and 2D-NMR, ESI-MS, HR-ESI-MS, and CD experiments.

Full text of DOI:10.1002/hlca.201500063

Helvetica Chimica Acta – Vol. 98 (2015)
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New Monoterpenoids from Fruits of Gardenia jasminoides var. radicans
by Shao-Fu Yu, Xiao-Jun Huang, Shu-Na Fu, Chun Wu, Wen-Cai Ye, and Guang-Xiong Zhou*
Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University,
601 West Huangpu Avenue, Guangzhou 510632, P. R. China
(phone: þ 86-20-85221469; fax: þ 86-20-85221559; e-mail: guangxzh@sina.com)
One new lactone, cyclopentanepyrone A (1), and two new monoterpenoids, gardeterpenone A (2)
and jasminoside V (3), were isolated from the fruits of Gardenia jasminoides var. radicans, along with
four known monoterpenoids, 4 – 7, which were isolated from this plant for the first time. The structures of
the isolates were elucidated by extensive spectroscopic studies, including UV, IR, 1D- and 2D-NMR,
ESI-MS, HR-ESI-MS, and CD experiments.
Introduction. – Gardenia jasminoides var. radicans, as a variant of G. jasminoides
J.Ellis [1], is mainly distributed in some southern provinces of China. At present, there
are only a few reports on its chemical constituents [2 – 6]. Our previous investigations
of this plant revealed the presence of 13 iridoids, five flavonoids, four crocins, one
monoterpene, five triterpenes, flavonoid glycosides, and five other compounds [4 – 7].
Our present investigation led to the discovery of three new monoterpenoid compounds,
namely one new lactone, cyclopentanepyrone A (1), one new monoterpene,
gardeterpenone A (2), and one monoterpenoid glycoside, jasminoside V (3), from
the fruits of this plant, as well as four known monoterpenoids, rehmapicrogenin (4), 6’-
O-sinapoyljasminoside A (5), jasminoside B (6), and jasminoside M (7), which are also
reported from this plant for the first time (Fig. 1).
Results and Discussion. – Compound 1 was obtained as brownish oil. Its HR-ESI-
MS exhibited a protonated molecular ion at m/z 183.1018 ([M þ H]þ), in agreement
with the molecular formula C10H14O3. The UVabsorption maximum at 217 nm, and IR
absorption bands at 3420, 1760, 1683, and 1025 cmÀ1 suggested that 1 contains a OH and
an a,b-unsaturated lactone group. The NMR data (Table 1) of 1 showed a C¼C bond
between C(4) (d(H) 6.64 (t, J ¼ 3.0), d(C) 136.8) and C(5) (d(C) 131.3); one COO
signal at d(C) 172.3 (C(3)); two Me signals at d(H) 0.88 (s, Me(10))/d(C) 20.0 (C(10))
and d(H) 1.07 (s, Me(11))/d(C) 29.8 (C(11)); two CH2 signals at d(H) 4.07 – 3.96 (m,
HaÀC(1)), 4.52 (t, J ¼ 9.0, HbÀC(1))/d(C) 69.8 (C(1)) and d(H) 1.46 (dd, J ¼ 12.9, 10.2,
HaÀC(7)), 1.88 (dd, J ¼ 13.0, 6.2, HbÀC(7))/d(C) 47.5 (C(7)); one CH signal at d(H)
3.02 (tt, J ¼ 9.5, 3.8, HÀC(9))/d(C) 47.6 (C(9)), one CHÀO signal at d(H) 4.46 – 4.35 (m,
HÀC(6))/d(C) 67.3 (C(6)), and one saturated Cq-atom signal at d(C) 36.2 (C(8)).
In addition, the presence of a d-lactone unit was supported by the COO signal at
d(C) 172.3 (C(3)). The HMB correlations of HÀC(4) with C(3), C(5), C(6), and C(9),
as well as the COSY correlations HÀC(6)/CH2(7) and HÀC(9)/CH2(1) suggested the
presence of a ÀOÀCH2ÀCHÀC(¼CHÀC(O)À)ÀCH(OH)ÀCH2À moiety (Fig. 2). The
ꢀ 2015 Verlag Helvetica Chimica Acta AG, Zürich

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Fig. 1. Structures of 1 – 7
Table 1. 1H- and 13C-NMR Data (300 and 75 MHz, resp.; in CD3OD) of 1 and 2. d in ppm, J in Hz.
Position
1
2
d(H)
d(C)
d(H)
d(C)
1
4.07 – 3.96 (m, Ha)a),
4.52 (t, J ¼ 9.0, Hb)
69.8
202.1
2
3
4
5
6
7
159.0
150.3
40.0
53.1
123.8
62.0
172.3
136.8
131.3
67.3
6.64 (t, J ¼ 3.0)
2.35 (s)
6.18 (s)
4.41 (d, J ¼ 1.5)
4.46 – 4.35 (m)a)
1.46 (dd, J ¼ 12.9, 10.2, Ha),
47.5
1.88 (dd, J ¼ 12.9, 6.2, Hb)
8
9
10
11
36.2
47.6
20.0
29.8
5.42 (s, Ha), 5.39 (d, J ¼ 1.5, Hb)
114.1
28.6
28.6
3.02 (tt, J ¼ 9.5, 3.8)
0.88 (s)
1.07 (s)
1.17 (s)
1.17 (s)
a) Signal multiplicity pattern is unclear due to overlapping.
Me(10) and Me(11) groups correlated with C(8), C(7), and C(9) in the HMBC
spectrum, indicating that the two Me groups were connected to the saturated Cq-atom
C(8). Furthermore, a HMB correlation of HbÀC(1) with C(3) was observed. Taking
into account the four degrees of unsaturation, the planar structure of 1 was deduced.

Helvetica Chimica Acta – Vol. 98 (2015)
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Fig. 2. Key HMBC (H ! C) and COSY (—) correlations of 1 – 3
The 1H- and 13C-NMR signals (Table 1) of 1 were completely assigned with the aid of
the 1H,1H-COSY, HSQC, HMBC, and NOESY spectra.
Additionally, the NOE correlation between HÀC(6) and HÀC(9) suggested that
these H-atoms are on the same side of the molecule plane, leading to either (6R,9S)- or
(6S,9R)-configuration. The absolute configuration of 1 was elucidated by a quantum-
chemical circular dichroism (CD) calculation. The CD computation for 1 was
performed at the B3LYP/6 – 31G(d) level. The overall predicted CD curve was
compared with the experimental one, which implied a good agreement between the
calculated CD curve and the measured one (Fig. 3). Therefore, 1 was identified as
(5R,7aS)-5,6,7,7a-tetrahydro-5-hydroxy-7,7-dimethylcyclopenta[c]pyran-3(1H)-one
and named cyclopentanepyrone A.
Compound 2 was obtained as brownish jelly. The molecular formula, C10H14O2,
was determined from its HR-ESI-MS, which showed a quasi-molecular-ion peak at
m/z 167.1064 ([M þ H]þ). The UV maximum absorptions at 204 and 271 nm, and IR
absorptions bands at 3414, 1660, 1032, and 913 cmÀ1 indicated that 2 contains OH
1
and C¼O groups, and a conjugated diene unit. This was further supported by H-
and 13C-NMR spectra (Table 1). The 1D- and 2D-NMR data of 2 showed two C¼C
Fig. 3. CD Spectrum of 1 and its computed CD curve

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bonds between C(8) (d(H) 5.42 (s, Ha), 5.39 (d, J ¼ 1.5, Hb)/d(C) 114.1) and C(3) (d(C)
150.3) as well as C(6) (d(H) 6.18 (s)/d(C) 123.8) and C(2) (d(C) 159.0), one C¼O
signal at d(C) 202.1 (C(1)), two Me signals at d(H) 1.17 (s, Me(9,10))/d(C) 28.6
(C(9,10)), one CH2 signal at d(H) 2.35 (s, HÀC(5))/d(C) 53.1 (C(5)); one CH2O signal
at d(H) 4.41 (d, J ¼ 1.5, HÀC(7))/d(C) 62.0 (C(7)), and one saturated Cq-atom signal at
d(C) 40.0 (C(4)).
In the HMBC spectrum (Fig. 2), the correlations of Me(9) and Me(10) with C(4),
C(5), and C(3), suggested that the two Me groups were connected to C(4). The long-
range correlations of HaÀC(8), HbÀC(8), and HÀC(6) with C(3) and C(2) indicated
a conjugated diene unit. Meanwhile, the correlations of CH2(7) with C(2) and C(6)
determined the linkage of the CH2O group to C(6). Besides, the HMB correlations of
HÀC(6) with C(1) and of CH2(5) with C(1) indicated that the C¼O group (C(1)) was
located between C(5) and C(2). Therefore, 2 was identified as (2E)-2-(2-hydroxy-
ethylidene)-4,4-dimethyl-3-methylidenecyclopentanone, and named gardeterpenone
A.
Compound 3 was obtained as white jelly. The molecular formula, C21H32O11, was
deduced from the pseudo-molecular-ion peak at m/z 483.1036 ([M þ Na]þ) in the
positive-ion-mode HR-ESI-MS. The UV maximum peaks at 204 and 277 nm, and the
IR absorption bands at 3404, 1713, and 1061 cmÀ1 revealed that 3 contains OH groups,
an ester C¼O group, and a conjugated diene unit. According to the anomeric H-atom
signal at d(H) 5.60 (d, J ¼ 7.9, HÀC(1’)) and the C-atom signals at d(C) 95.8 (C(1’)),
74.0 (C(2’)), 78.2 (C(3’)), 71.1 (C(4’)), 78.1 (C(5’)), and 69.6 (C(6’)) (Table 2), the
presence of a b-d-glucopyranosyl moiety was indicated. Meanwhile, a b-d-xylopyr-
anosyl unit was deduced based on the anomeric H-atom signal at d(H) 4.35 (d, J ¼ 7.4,
HÀC(1’’)) and the C-atom signals at d(C) 105.3 (C(1’’)), 75.0 (C(2’’)), 77.7 (C(3’’)), 71.2
(C(4’’)), and 66.9 (C(5’’)) [8]. Acid hydrolysis and derivatization of 3 followed by
HPLC analysis of the derivatives, determined b-d-glucose and b-d-xylose as
monosaccharide residues in the molecule [9]. Except for the signals of two sugar
residues, the 13C-NMR and DEPT spectra of 3 exhibited ten C-atom signals, including
Table 2. 1H- and 13C-NMR Data (300 and 75 MHz, resp.; in CD3OD) of 3. d in ppm, J in Hz.
Position
d(H)
d(C)
Position
d(H)
d(C)
1
2
3
4
5
6
7
8
9
34.6
40.7
3’
4’
5’
6’
3.47 (d, J ¼ 2.7)
78.2
71.1
78.1
69.6
2.08 – 2.22 (m)a)
3.50 (s)
5.97 (dt, J ¼ 9.6, 4.0)
130.4
129.2
134.9
133.8
20.2
26.6
26.3
170.1
95.8
74.0
3.60 (dd, J ¼ 8.2, 4.9)
4.11 (dd, J ¼ 11.6, 1.7),
3.80 – 3.75 (m)a)
4.35 (d, J ¼ 7.4)
5.90 (dt, J ¼ 9.6, 1.5)
1’’
2’’
3’’
4’’
5’’
105.3
75.0
77.7
71.2
66.9
1.86 (s)
1.16 (s)
1.15 (s)
3.23 (dd, J ¼ 5.3, 3.5)
3.33 (dd, J ¼ 3.1, 1.7)
3.40 – 3.35 (m)a)
3.87 (dd, J ¼ 11.4, 5.2),
3.17 (d, J ¼ 11.4)
10
1’
2’
5.60 (d, J ¼ 7.9)
3.44 (s)
a) Signal multiplicity pattern is unclear due to overlapping.

Helvetica Chimica Acta – Vol. 98 (2015)
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an ester C¼O group (d(C) 170.1 C(10)), two olefinic Cq-atoms (134.9 (C(5)) and 133.8
(C(6))), two olefinic CH groups (d(H) 5.97 (dt, J ¼ 9.6, 4.0, HÀC(3))/d(C) 130.4 (C(3))
and d(H) 5.90 (dt, J ¼ 9.6, 1.5, HÀC(4))/d(C) 129.2 (C(4))), a CH2 group (d(H) 2.08 –
2.22 (m, CH2(2))/d(C) 40.7 (C(2))), a saturated Cq-atom (d(C) 34.6 (C(1))), together
with three Me groups (d(H) 1.86 (s, Me(7))/d(C) 20.2 (C(7)), d(H) 1.66 (s, Me(8))/
d(C) 26.6 (C(8)), and d(H) 1.65 (s, Me(9))/d(C) 26.3 (C(9))). Complete and
combinational analysis of 13C-NMR, HSQC, and HMBC spectra allowed deducing
the constitution of the aglycone moiety as a monoterpene (Fig. 1).
The HMB correlation of the H-atom at d(H) 5.60 (HÀC(1’)) with the C¼O C-atom
at d(C) 170.1 (C(10)) suggested that the glucopyranosyl moiety is attached to the C¼O
C-atom of the aglycone residue. Besides, the two sugar moieties formed a b-d-Xyl-
(1’’ ! 6’)-b-d-Glc connection on the basis of the correlation of the H-atom at d(H) 4.35
(HÀC(1’’)) with the C-atom at d(C) 69.6 (C(6’)) in the HMBC spectrum. Therefore, 3
was identified as 1-O-[(2,6,6-trimethylcyclohexa-1,3-dien-1-yl)carbonyl]-6-O-b-d-xy-
lopyranosyl-b-d-glucopyranose. It is the disaccharide of a monoterpene, named
jasminoside V.
In addition, the known compounds were identified as rehmapicrogenin (4) [10], 6’-
O-sinapoyljasminoside A (5) [11], jasminoside B (6) [11], and jasminoside M (7) [8]
(Fig. 1) by comparing their spectroscopic data with reference values.
This work was financially supported by the Chinese National S & T Special Project on Major New
Drug Innovation (2011ZX09307-002-01).
Experimental Part
General. Standard sugars, b-d-glucose and a-l-rhamnose, and reagent l-cysteine methyl ester were
purchased from Adamas-beta Company (Basel, Switzerland). o-Tolyl isothiocyanate was purchased from
Sigma Company (Santa Clara, CA, USA). All reagents were purchased from Tianjin Damao Chemical
Company (Tianjin, P. R. China). Thin-layer chromatography (TLC): precoated aluminum silica gel
HSAF 254 plates (SiO2; 1 mm; Yantan, P. R. China); spraying reagent, 10% H2SO4/EtOH. Column
chromatography (CC): SiO2 (300 – 400 mesh; Qingdao Haiyang Chemical Group Corporation; Qingdao,
P. R. China), ODS (50 mm; YMC, Tokyo, Japan), and Sephadex LH-20 (GE Healthcare, Sweden). Anal.
and semi-prep. reversed-phase HPLC: Agilent 1200 (Agilent Technologies, Santa Clara, CA, USA) with
an XB-C18 column (4.6 Â 250 mm, 5 mm; Welch Materials Inc.) for analysis and an Ultimateꢀ XB-C18
column (21.2 Â 250 mm, 5 mm; Welch Materials Inc.) for purification. Optical rotations: JASCO P-1020
automatic digital polarimeter (JASCO International Co., Ltd., Tokyo, Japan). UV Spectra: JASCO V-550
UV/VIS spectrometer (JASCO International Co., Ltd., Tokyo, Japan); lmax (log e) in nm. CD Spectra:
Chirascan spectropolarimeter (Applied Photophysics Ltd., U.K.); at r.t. IR Spectra: JASCO FT/IR-480
1
plus FT-IR spectrometer (JASCO International Co., Ltd., Tokyo, Japan); n˜ in cmÀ1. H- and 13C-NMR
spectra: Bruker Avance III 300 MHz spectrometer (300 and 75 MHz, resp.; Bruker Biospin, Fällanden,
Switzerland); in CD3OD; d in ppm rel. to Me4Si as internal standard, J in Hz. ESI-MS: LCQ Advantage
Max mass spectrometer (Thermo Finnigan, San Diego, CA, USA); in m/z. HR-ESI-MS: Agilent 6210
LC/MSD TOF mass spectrometer (Agilent Technologies, Santa Clara, CA, USA); in m/z.
Plant Material. Dried ripe fruits of G. jasminoides var. radicans were collected from Bozhou Market
for Chinese Materia Medica, Anhui Province, P. R. China, in October 2011 and authenticated by G.-X.
Zhou at the College of Pharmacy, Jinan University. A voucher specimen was deposited with the herbal
museum of the college, Guangzhou, P. R. China.
Extraction and Isolation. The dried ripe fruits (7.0 kg) of G. jasminoides var. radicans were ground
into powder, and the powder was heated under reflux with 70% EtOH (3 Â 15 l, 3 h each). The extract
was concentrated in vacuo to yield a dark-brown residue (800 g), which was suspended in 3.0 l of H2O,

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and then partitioned with petroleum ether (PE), AcOEt, and BuOH (3 Â 3.0 l, 3 h each), successively.
The AcOEt extract (80 g) was subjected to CC (SiO2; CHCl3/MeOH 100 :0 to 0 :100) to give nine
fractions, Frs. 1 – 9, which were merged according to their TLC pattern. Fr. 3 (7.2 g) was subjected to CC
(SiO2; PE/acetone 50 :1, 25 :1, 20 :1, 10 :1, 5 :1, 3 :1, 1:1, and 0 :1) to furnish 4 (23.1 mg) and ten fractions,
Frs. 3.1 – 3.10. Furthermore, Fr. 3.5 (0.4 g) was separated by prep. HPLC (MeCN/H2O 15 :85) to afford 1
(7.2 mg) and 2 (6.8 mg). Compound 5 (11.2 mg) was purified from Fr. 3.3 (0.4 g) by CC (Sephadex LH-
20; CHCl3/MeOH 1:1, isocratic solvent system). Additionally, Fr. 6 (5.8 g) was subjected to CC (SiO2;
CHCl3/MeOH 1000 :1, 100 :1, 50 :1, 30 :1, 20 :1, 10 :1, 8 :2, 1:1, and 0 :1) to give eight subfractions,
Frs. 6.1 – 6.8. Fr. 6.2 (0.5 g) was separated by prep. HPLC (MeOH/H2O 50 :50) to yield 3 (7.9 mg). Fr. 6.4
(0.9 g) was further subjected to CC (Sephadex LH-20; CHCl3/MeOH 1:1, isocratic solvent system) to
yield 6 (4.2 mg) and 7 (18.7 mg).
Cyclopentanepyrone A (¼(5R,7aS)-5,6,7,7a-Tetrahydro-5-hydroxy-7,7-dimethylcyclopenta[c]pyran-
3(1H)-one; 1). Brown oil. [a]2D5 ¼ À15.8 (c ¼ 0.50, MeOH). UV (MeOH): 217 (4.03). IR (KBr): 3420,
1
2959, 1760, 1683, 1216, 1156, 1025, 751. H- and 13C-NMR: see Table 1. ESI-MS: 183 ([M þ H]þ). HR-
ESI-MS: 183.1018 ([M þ H]þ, C10H15O3þ ; calc. 183.1016).
Gardeterpenone A (¼(2E)-2-(2-Hydroxyethylidene)-4,4-dimethyl-3-methylidenecyclopentanone; 2).
Brown jelly. UV (MeOH): 204 (4.05), 271 (4.04). IR (KBr): 3414, 2966, 2937, 1660, 1286, 1105, 1032, 913,
762. 1H- and 13C-NMR: see Table 1. ESI-MS: 167 ([M þ H]þ). HR-ESI-MS: 167.1064 ([M þ H]þ,
C10H15Oþ2 ; calc. 167.1067).
Jasminoside V (¼1-O-[(2,6,6-Trimethylcyclohexa-1,3-dien-1-yl)carbonyl]-6-O-b-d-xylopyranosyl-b-
d-glucopyranose; 3). White jelly. [a]2D5 ¼ À16.2 (c ¼ 0.50, MeOH). UV (MeOH): 204 (4.02), 277 (4.05).
1
IR (KBr): 3404, 2959, 2921, 1713, 1648, 1458, 1377, 1061. H- and 13C-NMR: see Table 2. ESI-MS: 483
([M þ Na]þ). HR-ESI-MS: 483.1836 ([M þ Na]þ, C21H32NaO1þ1 ; calc. 483.1837).
Acid Hydrolysis of 3 and Determination of the Absolute Configuration of Sugars. The absolute
configurations of the two monosaccharide residues of 3 were identified by the method of Tanaka [9].
Compound 3 (1 mg) was hydrolyzed by heating in 2m HCl for 4 h at 708. After drying in vacuo, the
residue was dissolved in H2O and extracted with AcOEt. Then, the aq. layer was collected. After drying
under reduced pressure, the residue was dissolved in pyridine (1 ml) containing l-cysteine methyl ester
hydrochloride (1 mg) and heated at 608 for 1 h. A soln. (0.1 ml) of o-tolylisothiocyanate (0.5 mg) in
pyridine was added to the mixture, which was heated at 608 for 1 h. Then, the mixture was directly
analyzed by reversed-phase HPLC (XB-C18) with isocratic elution of 25% MeCN containing 0.1%
AcOH for 60 min; flow rate, 1 ml minÀ1; UV detector (254 nm). The peaks at tR 17.34 and 19.52 min
coincided with the corresponding derivatives of b-d-glucose and b-d-xylose.
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Received January 22, 2015