Two new phenolic compounds from Artemisia iwayomogi

Article abstract of DOI:10.1002/hlca.201300170

Two new phenolic compounds, (Z)-5′-hydroxyjasmone 5′-O-{6″-O-[(E)-caffeoyl]-β-D-glucopyranoside} (1) and quercetin-7-O-β-D-glucuronide methyl ester (2), along with ten known phenolic compounds, 3-12, were isolated from the aerial parts of Artemisia iwayom

Full text of DOI:10.1002/hlca.201300170

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Two New Phenolic Compounds from Artemisia iwayomogi
by Xi-Tao Yana), Yan Dinga)b), Wei Li a), Ya-Nan Suna), Seo-Young Yanga), Young-Sang Kohc),
and Young-Ho Kim*a)
a) College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea
(phone: þ 82-42-821-5933; fax: +82-42-823-6566; e-mail: yhk@cnu.ac.kr)
b) School of Food Science and Technology, Dalian Polytechnic University, Dalian 116-034, P. R. China
c) School of Medicine, Jeju National University, Jeju 690-756, Korea
Two new phenolic compounds, (Z)-5’-hydroxyjasmone 5’-O-{6’’-O-[(E)-caffeoyl]-b-d-glucopyrano-
side} (1) and quercetin-7-O-b-d-glucuronide methyl ester (2), along with ten known phenolic
compounds, 3 – 12, were isolated from the aerial parts of Artemisia iwayomogi. Their structures were
elucidated by spectroscopic methods, including 1D- and 2D-NMR, and HR-ESI-TOF-MS techniques.
The inhibitory effects of compounds 1 – 12 on the LPS-stimulated production of IL-12 p40, IL-6, and
TNF-a in bone marrow-derived dendritic cells were evaluated.
Introduction. – Since the discovery of artemisinin in the leaves of Artemisia annua
in the early 1970s, plants belonging to the Artemisia genus have attracted considerable
attention for their chemical constituents. Artemisia iwayomogi (Compositae), a
member of the Artemisia genus, is a perennial herb widely distributed in Northeast
Asian, especially Korea. The aerial parts of A. iwayomogi have long been used in
traditional Korean medicine (called ꢀHan In Jinꢁ) to cure various infectious diseases
such as carbuncle, sores, cholecystitis, and hepatitis, and to treat fever, inflammation,
and jaundice [1][2]. Previous phytochemical investigations on this plant led to the
isolation of phenolic compounds, terpenes, and coumarins as major constituents [3 – 6].
In the course of our ongoing search for novel anti-inflammatory compounds from
medicinal plants, twelve compounds were isolated from a MeOH extract of the aerial
parts of A. iwayomogi, including two new phenolic compounds, (Z)-5’-hydroxyjasmone
5’-O-{6’’-O-[(E)-caffeoyl]-b-d-glucopyranoside} (1) and quercetin-7-O-b-d-glucuro-
nide methyl ester (2), and ten known phenolic compounds: patuletin 3-O-b-d-
glucopyranoside (3) [7], quercetin (4) [8], citrusin C (5) [9], myrciaphenone A (6)
[10], annphenone (7) [11], erythro-1,2-bis(4-hydroxy-3-methoxyphenyl)propane-1,3-
diol (8) [12][13], threo-1,2-bis(4-hydroxy-3-methoxyphenyl)propane-1,3-diol (9) [13],
protocatechuic aldehyde (10) [14], chlorogenic acid methyl ester (11) [15], and 3,4-
di(O-caffeoyl)isoquinic acid (12) [16] (Fig. 1). Among them, compounds 3 and 8 – 12
were isolated from this plant for the first time. Herein, we describe the isolation and
structure elucidation of the two new phenolic compounds, as well as the anti-
inflammatory activities of the isolates in LPS-stimulated bone marrow-derived
dendritic cells.
ꢂ 2014 Verlag Helvetica Chimica Acta AG, Zꢃrich

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Fig. 1. The structures of compounds 1 – 12
Results and Discussion. – Compound 1 was obtained as a white amorphous powder.
The molecular formula was determined as C26H32O10 by high-resolution electrospray-
ionization time-of-flight mass spectrometry (HR-ESI-TOF-MS) (m/z 503.1923 ([M ꢀ
H]ꢀ)). The IR spectrum showed strong absorption bands for OH (3365 cmꢀ1) and
conjugated CO groups (1684 cmꢀ1), and conjugated olefinic bonds (1634 cmꢀ1). The
1H-NMR spectrum of 1 (Table) exhibited downfield signals of three aromatic H-atoms
at d(H) 6.99 (d, J ¼ 2.1, HꢀC(2’’’)), 6.89 (dd, J ¼ 8.3, 2.1, HꢀC(6’’’)), and 6.74 (d, J ¼ 8.3,
HꢀC(5’’’)), revealing one typical ABX coupling system, and of four olefinic H-atoms at
d(H) 7.52 (d, J ¼ 15.8, HꢀC(7’’’)), 6.24 (d, J ¼ 15.8, HꢀC(8’’’)), 5.38 (dtt, J ¼ 10.9, 7.6, 1.4,
HꢀC(3’)), and 5.27 (dtt, J ¼ 10.9, 6.9, 1.4, HꢀC(2’)), suggesting the presence of both
(E)- and (Z)-form C¼C bonds. Moreover, the 1H-NMR spectrum of 1 showed signals
corresponding to five O-bearing CH groups at d(H) 4.31 (d, J ¼ 8.3, HꢀC(1’’)) and
3.19 – 3.54 (m, HꢀC(2’’,3’’,4’’,5’’)), two pairs of O-bearing CH2 groups at d(H) 4.48 (dd,
J ¼ 11.6, 2.1, HaꢀC(6’’)) and 4.30 (dd, J ¼ 11.6, 6.2, HbꢀC(6’’)), and 3.78 (dt, J ¼ 9.6, 7.6,
HaꢀC(5’)) and 3.61 (dt, J ¼ 9.6, 6.9, HbꢀC(5’)), which were supported by DEPT-135 and
HMQC data, four CH2 groups in the range of d(H) 2.91 – 2.24 (m), and one Me group
at d(H) 2.01 (s, Me(6)). Analyses of 13C-NMR, DEPT, and HMQC data revealed that 1
contains 26 C-atoms comprising one Me, six CH2, and twelve CH groups, and seven
quaternary C-atoms (Table). These spectral data implied the presence of one caffeoyl,

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Table. 1H- and 13C-NMR Data (600 and 150 MHz, resp.) of 1 (CD3OD) and 2 ((D6)DMSO). d in ppm, J
in Hz. Atom numbering as indicated in Fig. 1.
Position
1
Position
2
d(H)
d(C)
d(H)
d(C)
1
2
3
4
5
6
1’
2’
174.8
139.9
212.2
35.3
32.7
17.6
2
3
4
5
6
7
8
9
147.7
136.1
176.0
160.5
98.6
2.24 – 2.26 (m)
2.42 – 2.44 (m)
2.01 (s)
2.88 – 2.91 (m)
5.27 (dtt, J ¼ 10.9, 6.9, 1.4)
5.38 (dtt, J ¼ 10.9, 7.6, 1.4)
2.46 – 2.49 (m)
6.44 (d, J ¼ 1.8)
6.81 (d, J ¼ 1.8)
162.2
94.0
22.3
129.0
155.8
104.8
121.8
115.4
145.1
148.0
115.6
3’
4’
5’
127.5 10
29.4 1’
70.8 2’
104.8 3’
75.2 4’
78.1 5’
72.0 6’
75.5 1’’
3.61 (dt, J ¼ 9.6, 6.9), 3.78 (dt, J ¼ 9.6, 7.6)
7.72 (d, J ¼ 1.8)
6.90 (d, J ¼ 8.2)
1’’
2’’
3’’
4’’
5’’
6’’
1’’’
2’’’
3’’’
4’’’
5’’’
6’’’
7’’’
8’’’
9’’’
4.31 (d, J ¼ 8.3)
3.19 (dd, J ¼ 8.3, 7.6)
3.34 – 3.39 (m)
3.31 – 3.36 (m)
3.51 – 3.54 (m)
7.56 (dd, J ¼ 8.2, 1.8) 120.1
5.33 (d, J ¼ 7.3)
3.28 – 3.35 (m)
3.29 – 3.37 (m)
3.35 – 3.42 (m)
4.21 (d, J ¼ 10.1)
99.0
72.8
75.4
71.3
75.2
169.3
52.0
4.30 (dd, J ¼ 11.6, 6.2), 4.48 (dd, J ¼ 11.6, 2.1) 64.9 2’’
127.8 3’’
6.99 (d, J ¼ 2.1)
115.2 4’’
147.0 5’’
149.8 6’’
116.6 MeO
123.2
147.2
115.0
169.2
6.74 (d, J ¼ 8.3)
3.67 (s)
6.89 (dd, J ¼ 8.3, 2.1)
7.52 (d, J ¼ 15.8)
6.24 (d, J ¼ 15.8)
Fig. 2. Key HMBCs (H ! C) of 1
one 5’-hydroxyjasmone, and one glucosyl moiety in the molecule of 1, which was
confirmed by HMBCs and comparison of the NMR data with those reported in
[17][18]. The C¼C bond in the caffeoyl moiety was determined to be (E)-configured
based on its coupling constant (J ¼ 15.8 Hz) between the HꢀC(7’’’) and HꢀC(8’’’),
while the C¼C bond in the 5’-hydroxyjasmone moiety was determined to be (Z)-
configured due to the smaller coupling constant (J ¼ 10.9 Hz) between the HꢀC(2’) and

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HꢀC(3’). Correlations in the HMBC spectrum (Fig. 2) observed from the signal at
d(H) 4.31(HꢀC(1’’)) to that at d(C) 70.8 (CH2(5’)), and from the signals at d(H) 3.61
and 3.78 (CH2(5’)) to that at d(C) 104.8 (CH(1’’)), indicated that the OꢀCH2(5’) group
of the (Z)-5’-hydroxyjasmone moiety was connected to the anomeric C-atom
(HꢀC(1’’)) of the glucosyl moiety. Correlations from the signals at d(H) 4.30 and
4.48 (CH2(6’’)) to that at d(C) 169.2 (C(9’’’)) suggested that the caffeoyl moiety was
linked to CH2(6’’) of the glucosyl moiety. The b-configuration at the anomeric center of
the glucosyl moiety was supported by the relatively large J value (J ¼ 8.3 Hz). The
absolute d-configuration of the glucosyl moiety was determined by GC analysis.
Consequently, the structure of 1 was elucidated as (Z)-5’-hydroxyjasmone 5’-O-{6’’-O-
[(E)-caffeoyl]-b-d-glucopyranoside}.
Compound 2 was obtained as a yellow amorphous powder. Its molecular formula
was determined as C22H20O13 on the basis of HR-ESI-TOF-MS data (m/z 491.0828
([M ꢀ H]ꢀ)). The IR spectrum showed absorption bands for OH groups (3308 cmꢀ1),
an ester CO group (1740 cmꢀ1), an a,b-unsaturated CO group (1654 cmꢀ1), and a
1
conjugated olefinic bond (1612 cmꢀ1). The H-NMR spectrum of 2 (Table) exhibited
signals for three ABX coupling aromatic H-atoms at d(H) 7.72 (d, J ¼ 1.8, HꢀC(2’)),
7.56 (dd, J ¼ 8.2, 1.8, HꢀC(6’)), and 6.90 (d, J ¼ 8.2, HꢀC(5’)), two meta-coupling
aromatic H-atoms at d(H) 6.81 (d, J ¼ 1.8, HꢀC(8)) and 6.44 (d, J ¼ 1.8, HꢀC(6)), for
five H-atoms in the range of d(H) 3.28 – 5.33, and one MeO group at d(H) 3.67 (s). The
13C-NMR spectrum of 2, combined with the HMQC spectrum, showed 22 C-atom
signals, including those of one Me group and ten CH groups, and eleven quaternary C-
atoms. The quaternary C-atom signals at d(C) 176.0, 147.7, 136.1, and 104.8 were typical
of C(4), C(2), C(3), and C(10) of a 3-O-substituted flavonoid moiety. Additional
signals of five O-bearing aromatic C-atoms at d(C) 162.2 (C(7)), 160.5 (C(5)), 155.8
(C(9)), 148.0 (C(4’)), and 145.1 (C(3’)) suggested that this 3-O-substituted flavonoid
moiety corresponded to a quercetin (2-(3’,4’-dihydroxyphenyl)-3,5,7-trihydroxy-4H-
chromen-4-one) group [8]. Based on comparison of the NMR spectral data with those
reported in literature [19][20], the signals of seven O-bearing C-atoms at d(C) 99.0
(C(1’’)), 72.8 (C(2’’)), 75.4 (C(3’’)), 71.3 (C(4’’)), 75.2 (C(5’’)), 169.3 (C(6’’)), and 52.0
(Me(7’’)) were consistent with the b-d-glucuronide methyl ester group. The larger
coupling constant of the anomeric H-atom signal at d(H) 5.33 (d, J ¼ 7.3) indicated the
b-configuration of the glucuronide methyl ester group. This group was also evidenced
by the HMBCs (Fig. 3), especially the key HMBCs HꢀC(5’’)/C(6’’) and Me(7’’)/C(6’’).
The HMBC from the signal at d(H) 5.33 (d, J ¼ 7.3, HꢀC(1’’)) to that at d(C) 162.2
(C(7)) indicated that the b-d-glucuronide methyl ester group was linked to the
quercetin group through C(1’’)ꢀOꢀC(7). Thus, the structure of 2 was determined as
quercetin-7-O-b-d-glucuronide methyl ester.
Inhibitory effects of the isolated compounds, 1 – 12, on proinflammatory cytokines
were evaluated by evaluating the production of IL-12 p40, IL-6, and TNF-a in LPS-
stimulated bone marrow-derived dendritic cells. SB203580, an inhibitor of cytokine
suppressive binding protein/p38 kinase, was used as a positive control, which inhibited
IL-12 p40, IL-6, and TNF-a production with IC50 values of 5.0 ꢁ 0.2, 3.5 ꢁ 0.1, and 7.2 ꢁ
0.3 mm, respectively. Among the compounds, a mixture of compounds 8 and 9 (a pair of
diastereoisomers) and compound 4 exhibited potent inhibitory activities against IL-12
p40 production with IC50 values of 0.03 ꢁ 0.001 and 5.1 ꢁ 0.2 mm, respectively.

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Fig. 3. Key HMBCs (H ! C) of 2
Moreover, compound 7 showed moderate inhibitory activity against IL-12 p40 with an
IC50 value of 21.6 ꢁ 1.5 mm. However, only compound 4 inhibited IL-6 and TNF-a
production with IC50 values of 52.93 ꢁ 2.2 mm and 50.11 ꢁ 2.1 mm, respectively. The
remaining compounds did not show any significant activity against the production of
IL-12 p40, IL-6, and TNF-a in LPS-stimulated bone marrow-derived dendritic cells
(IC50 > 60 mm).
This work was financially supported by the Technology Development Program for Agriculture and
Forestry (No. 108079-3), the Ministry for Agriculture, Forestry and Fisheries, Korea, and the Priority
Research Centers Program through the National Research Foundation of Korea (NRF) funded by the
Ministry of Education, Science and Technology (2009-0093815), Korea.
Experimental Part
General. Column chromatography (CC): silica gel (SiO2; 40 – 75 and 75 – 200 mm particle size; Fuji
Silysia Chemical Ltd., Japan) and YMC RP-18 resins (30 – 50 mm particle size; Fuji Silysia Chemical Ltd.,
Japan). TLC: Silica gel 60 F254 and RP-18 F254S plates (Merck, DE-Darmstadt). GC: Shimadzu GC-2010
spectrometer. Optical rotations: Jasco P-2000 digital polarimeter. UV Spectra: Shimadzu UV-1800
spectrophotometer; lmax (log e) in nm. IR Spectra: Nicolet 380 FT-IR spectrometer; KBr pellets; ˜n in
cmꢀ1. NMR Spectra: Jeol ECA 600 spectrometer (1H- and 13C-NMR at 600 and 125 MHz, resp.); d in ppm
rel. to Me4Si as an internal standard, J in Hz. ESI-MS: Agilent 1100 LC-MSD trap spectrometer. HR-ESI-
TOF-MS: Agilent 6530 Accurate-Mass Q-TOF LC/MS system; in m/z.
Plant Material. The aerial parts of Artemisia iwayomogi were collected on Jeju Island in June 2007,
and taxonomically identified by Y.-H. K. at the College of Pharmacy, Chungnam National University,
Daejeon, Korea. A voucher specimen (CNU07105) has been deposited with the herbarium of the above
college.
Extraction and Isolation. The dried aerial parts of Artemisia iwayomogi (3 kg) were extracted with
MeOH under reflux (3 ꢂ 18 l, 12 h each). The combined extract was concentrated under reduced
pressure to yield a residue (465 g), which was suspended in H2O (3 l), and partitioned successively with
CHCl3 (4 ꢂ 3 l) and AcOEt (4 ꢂ 3 l) to yield a CHCl3-soluble fraction (94 g), an AcOEt-soluble fraction
(42 g), and a H2O fraction, resp. The AcOEt-soluble fraction was subjected to column chromatography
(CC; SiO2; CHCl3/MeOH 50 :1 to 10 :1) to afford six subfractions, Frs. 1 – 6. Fr. 2 (31 g) was further
subjected to repeated CC (SiO2; hexane/acetone 5 :1 to 0 :1), and then to CC (YMC C-18; H2O/MeOH
2 :1 to 1:1) to yield compounds 1 (26 mg), 4 (45 mg), 5 (13 mg), 6 (10 mg), 7 (30 mg), a mixture 8/9
(8 mg), 10 (24 mg), and 12 (420 mg). The H2O fraction was submitted to CC (Diaion HP-20; H2O/
MeOH 100 :0, 75 :25, 50 :50, 25 :75, 0 :100) to yield five fractions, Frs. A – E. Fr. C (eluted with H2O/
MeOH 1:1, 56 g) was subjected to CC (SiO2; CH2Cl2/MeOH/H2O 12 :1:0.05 to 1:1:0.1) to afford four
subfractions, Frs. C1 – C4. Fr. C2 was purified by repeated CC (YMC C-18; H2O/MeOH 2.5 :1 to 1:1) to

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Helvetica Chimica Acta – Vol. 97 (2014)
yield compounds 2 (22 mg) and 11 (26 mg). Fr. C3 was further purified by CC (YMC C-18; H2O/MeOH
1.5 :1 to 1:1) to yield compound 3 (10 mg).
(Z)-5’-Hydroxyjasmone 5’-O-{6’’-O-[(E)-caffeoyl]-b-d-glucopyranoside} (¼2-[(2Z)-5-[[6-O-[(2E)-
3-(3,4-Dihydroxyphenyl)-1-oxoprop-2-en-1-yl]-b-d-glucopyranosyl]oxy]pent-2-en-1-yl]-3-methyl-2-cy-
clopenten-1-one; 1). White powder. [a]1D8 ¼ ꢀ69.9 (c ¼ 1.0, MeOH). UV (MeOH): 234 (2.76), 330 (1.72).
IR (KBr): 3365, 1684, 1634, 1605, 1525, 1440, 1386, 1283, 1164, 1039, 851, 803. 1H- and 13C-NMR: see the
Table. HR-ESI-MS (neg.): 503.1923 ([M ꢀ H]ꢀ, C26H31O1ꢀ0 ; calc. 503.1917).
Quercetin-7-O-b-d-glucuronide methyl ester (¼2-(3,4-Dihydroxyphenyl)-3,5-dihydroxy-7-[(6-meth-
yl-b-d-glucopyranuronosyl)oxy]-4H-1-benzopyran-4-one; 2): Yellow powder. [a]1D8 ¼ ꢀ189.1 (c ¼ 1.0,
MeOH). UV (MeOH): 256 (1.86), 372 (1.60). IR (KBr): 3308, 1740, 1654, 1612, 1597, 1497, 1317, 1247,
1212, 1173, 1088, 1044, 1024, 1000. 1H- and 13C-NMR: see the Table. HR-ESI-MS (neg.): 491.0828 ([M ꢀ
H]ꢀ, C22H19Oꢀ13 ; calc. 491.0826).
Acid Hydrolysis. Compound 1 (2.0 mg) was dissolved in 1n HCl (dioxane/H2O 1:1, v/v, 1 ml) and
then heated to 808 in a water bath for 3 h. The cooled mixture was diluted with H2O (4 ml) and extracted
with AcOEt (3 ꢂ 5 ml). The aq. layer was thoroughly dried under N2 after neutralization with Ag2CO3.
The residues were dissolved in 0.1 ml of dry pyridine, and then l-cysteine methyl ester hydrochloride in
pyridine (0.06m, 0.1 ml) was added to the solns. The mixture was heated at 608 for 2 h, and 0.1 ml of
TMSCl (Me3SiCl) soln. was added, followed by heating at 608 for 1.5 h. The dried product were
partitioned with hexane and H2O (0.1 ml each), and the org. layer was analyzed by GC (column: SPB-1,
0.25 mm ꢂ 30 m; detector, FID; detector temp., 3008; column temp., 2108; injector temp., 2708; carrier
gas, He, 2 ml/min). The monosaccharide was confirmed as d-glucose by comparison of the retention time
of the monosaccharide derivative (tR 14.09 min) with that of authentic sugar derivatives (d-glucose
derivative: tR 14.11 min and l-glucose derivative: tR 14.26 min), which were prepared by the same
reaction from the standard glucoses.
Biological Assay. Bone marrow-derived dendritic cells (BMDCs) were grown from wild-type
C57BL/6 mice (Taconic Farm, NY, USA). Briefly, the mouse tibia and femur were obtained by flushing
with Dulbeccoꢁs modified Eagleꢁs medium to yield bone marrow cells. The cells were cultured in RPMI
1640 medium containing 10% heat-inactivated fetal bovine serum (FBS) (Gibco, NY, USA), 50 mm 2-
sulfanylethanol, and 2 mm glutamine supplemented with a 3% J558L hybridoma cell culture supernatant
containing granulocyte-macrophage colony-stimulating factor. The culture medium was replaced with
fresh medium every second day. At day 6 of culture, nonadherent cells and loosely adherent DC
aggregates were harvested, washed, and resuspended in RPMI 1640 supplemented with 5% FBS. The
BMDCs were incubated in 48-well plates at a density of 2 ꢂ 105 cells/ml, and then treated with the test
compounds in DMSO (2, 10, 25, and 50 mm) for 1 h before stimulation with 10 ng/ml LPS from
Salmonella minnesota (Alexis, NY, USA). Supernatants were harvested 16 h after stimulation.
Concentrations of murine IL-12 p40, IL-6, and TNF-a in the culture supernatant fraction were
determined by enzyme-linked immune-sorbent assay (BD Pharmingen, CA, USA) according to the
manufacturerꢁs instructions. The data are presented as mean ꢁ SD of at least three independent
experiments performed in triplicate.
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Received April 23, 2013