The constituents and their bioactivities of Houttuynia cordata

Article abstract of DOI:10.1248/cpb.57.1227

Chemical investigation on the whole plant of Houttuynia cordata has resulted in the isolation of two new compounds, named as houttuynoside A (1) and houttuynamide A (2), together with thirty-eight known compounds. The structures of 1 and 2 were elucidated

Full text of DOI:10.1248/cpb.57.1227

November 2009
Chem. Pharm. Bull. 57(11) 1227—1230 (2009)
1227
The Constituents and Their Bioactivities of Houttuynia cordata
a
a
b
,a,c
*
Shu-Chen CHOU, Chung-Ren SU, Yuh-Chi KU, and Tian-Shung WU
a Department of Chemistry, National Cheng Kung University; Tainan 701, Taiwan: b Department of Life Science, Fu-Jen
University; Taipei Hsien 242, Taiwan: and c Department of Pharmacy, China Medical University; Taichung 401, Taiwan.
Received May 5, 2009; accepted July 8, 2009; published online August 17, 2009
Chemical investigation on the whole plant of Houttuynia cordata has resulted in the isolation of two new
compounds, named as houttuynoside A (1) and houttuynamide A (2), together with thirty-eight known com-
pounds. The structures of 1 and 2 were elucidated on the basis of spectroscopic analysis. In the inhibitory effects
on herpes simplex virus type 1 (HSV-1) assay, norcepharadione B (10) showed good inhibitory activity against the
replication of HSV-1. In addition, the antioxidant and antityrosinase activities of some isolated compounds were
also evaluated. Among these compounds, quercitrin (25) and quercetin-3-O-b-D-galactopyranoside (26) showed
excellent 2,2-diphenyl-1-picrylhydrazyl radical-scavenging property with IC50 values of 31 and 63 mM, respec-
tively. Cepharadione B (9) exhibited strong tyrosinase inhibitory activity with an IC50 value of 170 mM.
Key words Euphorbiaceae; herpes simplex virus type 1; antioxidant; antityrosinase
Houttuynia cordata THUNB. (Saururaceae) is a native moiety. The 4-hydroxybenzoate moiety and 3,4-dihydroxy-
perennial herbaceous plant in the eastern and southern re- benzoate moiety were linked through glucosyl moiety at C-6ꢃ
gions of Asia. Recently, H. cordata has been used for the and C-1ꢃ, which were based on the heteronuclear multiple
treatment of herpes simplex virus type 1 (HSV-1), influenza bond coherence (HMBC) correlations with H-6ꢃ (dHꢁ4.70,
virus, human immunodeficiency virus type 1 (HIV-1),1) and 4.33, each 1H) to C-7ꢂ (dC 165.8) and H-1ꢃ (d 4.90) to d
chronic sinusitis and nasal polyps.2) Besides, the whole plant 150.3 (C-3), respectively. From the above spectroscopic data,
has also been reported to have the antileukemic activity,3) an- the structure of houttuynoside A was identified as 1.
ticancer activity,4) adjuvanticity,5) antioxidant action,6) and in-
Houttuynamide A (2) was isolated as colorless syrup. The
hibitory effects on anaphylactic reaction and mast cell activa- molecular formula of 2 was determined as C15H15NO2 from
tion.2) In our continuing research for bioactive compounds molecular ion peak at m/z 273.1004 in the HR-EI-MS. The
from medicinal plants, this paper deals with isolation, struc- IR spectrum displayed absorptions at 3353 and 1700 cmꢀ1,
ture elucidation of the new compounds, and evaluation of the due to hydroxyl and carbonyl groups. A 1,3,4-trisubstituted
1
anti-herpes simplex virus activity 1 (HSV-1), the antioxidant, phenyl group was observed in the H- and 13C-NMR spectra
and antityrosinase activities of the isolated compounds.
[ABX system at dH 7.24 (1H, d, Jꢁ2.0 Hz, H-2), 7.15 (1H,
dd, Jꢁ8.4, 2.0 Hz, H-6), and 6.78 (1H, d, Jꢁ8.4 Hz, H-5); dC
115.7 (C-2), 115.8 (C-5), 120.5 (C-6), 127.2 (C-1), 146.3 (C-
Results and Discussion
The MeOH extract of H. cordata was partitioned with 3) and 150.0 (C-4)] and the attachment of a –CONCH2CH2–
CHCl3 and H2O. The condensed chloroform extract was por- group [dH 3.49 (2H, t, Jꢁ7.5 Hz, H-8ꢃ) and 2.78 (2H, t,
tioned with n-hexane and 80% CH3OHaq. The H2O-soluble Jꢁ7.5 Hz, H-7ꢃ; dC 170.2 (C-7)] to the aromatic nucleus.
3
portion was further portioned with n-BuOH to give a dark This was confirmed by J-HMBC correlations from H-2 and
brown syrup. Through the further isolation of the subfrac- H-6 to C-7 and from H-8ꢃ to C-7 (d 170.2). The 1H- and 13C-
tions, it led to two new compounds and thirty-eight known NMR spectra of 2 also revealed the presence of a para sub-
compounds.
stituted phenyl group [A2B2 system at dH 7.06 (2H, d,
Houttuynoside A (1) was isolated as optically active color- Jꢁ8.6 Hz, H-2ꢃ, -6ꢃ) and 6.71 (2H, d, Jꢁ8.6 Hz, H-3ꢃ, -5ꢃ);
less syrup. The HR-FAB-MS of 1 exhibited a pesudomolecu- dC 116.5 (C-3ꢃ, -5ꢃ), 130.1 (C-2ꢃ, -6ꢃ), 131.5 (C-1ꢃ) and
lar ion peak at m/z 451.1244, consistent with the molecular 156.9 (C-4ꢃ)] to which is attached a –CH2CH2N– group as
formula C21H22O11. The IR spectrum showed absorption evidenced by HMBC correlations from H-7ꢃ to C-2ꢃ, C-6ꢃ
bands at 3392 and 1688 cmꢀ1 were assignable to hydroxyl and C-8ꢃ. These data indicated these two phenyl ring moi-
1
and carbonyl moieties. H-NMR spectrum showed the pres- eties were connected through –CH2CH2NHCO– linkage.
ence of a set of ABX protons at dH 7.50 (1H, d, Jꢁ2.9 Hz,
H-2), 7.33 (1H, dd, Jꢁ9.0, 2.9 Hz, H-6), and 6.79 (1H, d,
Jꢁ9.0 Hz, H-5), a set of A2B2-type aromatic protons at d
7.88 (2H, d, Jꢁ8.6 Hz, H-2ꢂ, -6ꢂ) and 6.90 (2H, d, Jꢁ8.6 Hz,
H-3ꢂ, -5ꢂ), and one glucopyranose unit. A three protons sin-
glet signal at d 3.84 was assigned for a methoxy group. Ac-
1
cording to the H- and 13C-NMR spectral data, it indicated
that the presence of a 4-hydroxybenzoate, 3,4-dihydroxyben-
zoate, and glucopyranosyl moiety. Acid hydrolysis of 1 and
chromatographic purification afforded D-glucose which was
compared with authentic sample of D-glucose. In addition,
the anomeric signal at d 4.33 (1H, dd, Jꢁ11.7, 7.2 Hz) sug-
gested the presence of a sugar residue with a b-D-glucosyl
Fig. 1. Structures and Significant HMBC Correlations of Houttuynoside
A (1) and Houttuynamide A (2)
© 2009 Pharmaceutical Society of Japan
∗ To whom correspondence should be addressed. e-mail: tswu@mail.ncku.edu.tw

1228
Vol. 57, No. 11
Table 1. Effects of Tested Compounds on HSV-1 Replication
From the above spectroscopic data, the structure of 2 was de-
termined and named as houttuynamide A.
Compounds (100 mM)
Inhibitory activity (%)
In addition, thirty-eight known compounds were identified
by comparison of their physical and spectroscopic data with
those of corresponding authentic samples or literature values.
These compounds are aristolactams 3—6 [aristolactam A II
(3),7) aristolactam B II (4),7) piperolactam A (5),8) and 3,4-
dimethoxy-N-methyl aristolactam (6)],9) oxoaporphines 7
and 8 [splendidine (7)1) and lysicamine (8)],10) 4,5-dioxoa-
porphines 9—11 [cepharadione B (9),8) norcepharadione B
(10),8) and noraritolodione (11)],1) amides 12—18 [N-(1-
hydroxymethyl-2-phenylethyl)benzamide (12),11) N-(4-hy-
droxyphenylethyl)benzamide (13),12) benzamide (14),13) 4-
hydroxybenzamide (15),14) 4-hydroxy-3-methoxybenzamide
(16),15) 6,7-dimethyl-1-ribitol-1-yl-1,4-dihydroquinoxaline-
2,3-dione (17),16) and (1H)-quinolinone (18)],17) indole 19
[indole-3-carboxylic acid (19)],18) ionones 20—24 [vomifo-
liol (20),19) dehydrovomifoliol (21),20) reseoside (22),21) 7-
(3,5,6-trihydroxy-2,6,6-trimethylcyclohexyl)-byt-3-en-2-one
(23),22) and 6-(9-hydroxy-but-7-ethyl)-1,1,5-trimethylcyclo-
hexane-3,5,6-triol (24)],23) flavonoids 25—27 [quercitrin
(25),24) quercetin-3-O-b-D-galactopyranoside (26),24) and
afzelin (27)],24) benzenoids 28—37 [vanillic acid (28),25)
methyl vanillate (29),26) vanillin (30),26) protocatechuic acid
(31),27) 4-hydroxybenzoic acid (32),28) methylparaben (33),29)
p-hydroxybenzaldehyde (34),30) cis and trans-methyl ferulate
(35, 36),31) and benzyl-b-D-glucopyranoside (37)],32) steroids
38 and 39 [b-sitosteryl glucoside (38)33) and b-sitosterol
(39)],25) as well as a triterpenoid 40 [cycloart-25-ene-3b,24-
diol (40)].34)
3
4
5
8.48ꢄ0.71
ꢀ3.08ꢄ0.29
20.48ꢄ0.00
3.24ꢄ2.12
46.38ꢄ1.06
17.71ꢄ3.53
ꢀ7.98ꢄ1.76
20.45ꢄ1.76
ꢀ2.74ꢄ4.23
2.74ꢄ5.64
25.44ꢄ1.76
6.73ꢄ4.49
5.49ꢄ3.17
13.47ꢄ3.17
14.21ꢄ2.82
3.24ꢄ4.94
9
10
11
14
22
23
25
27
28
31
32
37
40
Table 2. The DPPH Radical Scavenging Activities of Tested Compounds
Compounds
Activity (%) (250 mM)
IC50 (mM)
15
16
25
26
27
28
30
31
33
N.A.
N.A.
84
—
—
31
63
—
—
—
250
—
80
82
N.A.
N.A.
N.A.
50
N.A.
74
Vitamine E
Inhibitory effects of isolated compounds 3—5, 9—11, 14,
22, 23, 25, 27, 28, 31, 32, 37, and 40 on herpes simplex virus
type 1 (HSV-1) replication were investigated as compared
with acyclovia. As shown in Table 1, norcepharadione B (10)
significantly suppressed HSV-1 replication by 46.38ꢄ1.06%
at the concentration of 100 mM. Compounds 5, 22, and 27
showed moderate activities with inhibition percentages
20.48ꢄ0.00%, 20.45ꢄ1.76%, and 25.44ꢄ1.76%, respec-
tively. Hence, suppression of viral replication of norcephara-
dione B (10) might have an important implication for H. cor-
data therapeutic activity in virus infection. In addition, the
isolated compounds 15, 16, 25—28, 30, 31, and 33 were also
examined for their antioxidant properties using the 2,2-
diphenyl-1-picrylhydrazyl free radical (DPPH) assay in Table
2. Compounds 25, 26, and 31 were found to be active at
250 mM with inhibition percentages 84%, 82%, and 50%, re-
spectively. Quercitrin (25) and quercetin-3-O-b-D-galactopy-
ranoside (26) exhibited strong scavenging activity with IC50
values of 31 and 63 mM, respectively, which was compared to
the reference compound of vitamin E (IC50, 80 mM). The anti-
N.A.: no activity.
NMR, COSY, HMQC, HMBC, and NOESY spectra were recorded on
Bruker AVANCE-300, 500 and AMX-400 spectrometers, using tetramethyl-
silane (TMS) as internal standard. Standard pulse sequences and parameters
were used for the NMR experiments and all chemical shifts are reported in
parts per million (ppm, d). FAB-MS were obtained on a JEOL JMS-700
spectrometer, and EI-MS were obtained on a VG-70-250S spectrometer.
Column chromatography was performed on silica gel (70—230 mesh, 230—
400 mesh). Fractions were monitored by TLC (Merck precoated Si gel 60
F254 plates), using UV light. TLC was conducted on precoated Kieselgel 60
F 254 plates (Merck) and the spots were detected either by examining the
plates under a UV lamp or by treating the plates with a 10% methanolic so-
lution of p-anisaldehyde acid followed by heating at 110 °C.
Plant Materials The whole plant of H. cordata was collected in Taiwan
on July in 2004. The plant material was identified and authenticated by Prof.
C. S. Kuoh. A voucher specimen (HC04023) has been deposited in the
herbarium of National Cheng Kung University, Tainan, Taiwan.
Extraction and Isolation The air-dried and powdered whole plant of H.
cordata (9.4 kg) was extracted with hot MeOH (6ꢅ20 l) and concentrated
under reduced pressure to obtain a dark crude extract (810 g). Then it was
suspended in H2O and partitioned with CHCl3 to afford CHCl3- (440 g) and
H2O-soluble portions (360 g), respectively. The condensed chloroform ex-
tyrosinase activities of 3, 4, 9, 10, 15, 29, and 34 were also tract was portioned with n-hexane and 80% CH3OHaq. The H2O-soluble por-
tions was further portioned with n-BuOH to give a dark brown syrup
evaluated. Among these compounds, cepharadione B (9) ex-
hibited strong inhibitory activity with an IC50 value of
170 mM, compared to the reference compound of kojic acid
(IC50 value 160 mM).
(100 g).
The n-hexane layer was concentrated under reduced pressure to afford a
brown syrup (320 g), which was chromatographed on silica gel using gradi-
ents of n-hexane and ethyl acetate to give six fractions. Fraction 2 was
rechromatographed on silica gel using n-hexane–ethyl acetate (29 : 1 to 0 : 1)
as step gradients as eluents to obtain 40 (6.7 mg). Fraction 3 on column
chromatography over silica gel using stepwise gradients of n-hexane–ethyl
acetate (18 : 1 to 0 : 1) afforded the colorless crystal 39 (1.1 g). Fraction 4
was rechromatographed on a silica gel column with n-hexane–CHCl3 (2 : 1)
as step gradient mixtures to yield 6 (7.8 mg).
Experimental
General Melting points were determined using Yanagimoto MP-S3
micro melting point apparatus and were uncorrected. Optical rotations were
measured using a JASCO DIP-370 digital polarimeter. UV spectra were
recorded on a Hitachi U-3210 spectrophotometer, and IR spectra were
recorded on a Shimadzu FT-IR Prestige-21 spectrophotometer. H- and 13C-
1
The 80% CH3OH layer was concentrated and treated with 2% HCl and

November 2009
1229
CHCl3. The non-alkaloid layer (HCC) was condensed to obtain a brown
H-2ꢃ, -6ꢃ), 6.78 (1H, d, Jꢁ8.4 Hz, H-5), 6.71 (2H, d, Jꢁ8.6 Hz, H-3ꢃ, -5ꢃ),
5.00 (1H, br s, OH), 3.49 (2H, t, Jꢁ7.5 Hz, CH2-8ꢃ), 2.78 (2H, t, Jꢁ7.5 Hz,
CH2-7ꢃ); 13C-NMR (CD3OD, 125 MHz) d: 170.3 (C-7), 156.9 (C-4ꢃ), 150.0
(C-4), 146.3 (C-3), 131.5 (C-1ꢃ), 130.8 (C-2ꢃ, -6ꢃ), 127.2 (C-1), 120.5 (C-6),
116.3 (C-3ꢃ, -5ꢃ), 115.8 (C-5), 115.7 (C-2), 42.9 (C-8ꢃ), 35.9 (C-7ꢃ); EI-MS
m/z 273 [M]ꢆ (38); HR-EI-MS m/z: 273.1004 [M]ꢆ (Calcd for C15H15NO2,
273.1001).
Acid Hydrolysis of 1 A solution of all houttuynoside A (1) (1 mg) in
0.2 M HCl (dioxane–H2O, 1 : 1, 2.0 ml) was heated at 95 °C for 1 h under an
Ar atmosphere. The reaction mixture was chromatographed on a Sephadex
LH-20 column eluted with H2O to afford the sugar fraction. The sugar frac-
tion was analyzed by HPLC under the following conditions: column,
Aminex HPX-87H (7.8 mm i.d.ꢅ300 mm, 5 mm, Bio-Rad Laboratories,
Hercules, CA, U.S.A.); solvent, 5 mM H2SO4; flow rate, 0.6 ml/min; detec-
tion, RI and OR. Identification of D-glucose present in the sugar fraction was
carried out by comparison of its retention time and polarity with those of an
authentic sample: tR (min), 8.99 (D-glucose, positive polarity).
Cell Culture and Viruses Vero cells were cultured in minimal essential
medium (MEM; GIBCO, Grand Island, NY, U.S.A.) supplement with 10%
fetal calf serum (FCS; Hyclone, Logan, UT, U.S.A.), 100 U/ml penicillin,
and 100 mg/ml streptomycin and incubated at 37 °C in a 5% CO2 incubator.
To prepare HSV-1 (KOS strain, VR-1493, ATCC) stocks, Vero cells were in-
fected by HSV-1 at a multiplicity of infection (m.o.i.) of 3 plaque forming
units (PFU)/cell and harvested at 24 h postinfection and centrifuged at
1500ꢅg (Centrifuge 5810 R, Eppendorf) at 4 °C for 20 min. The supernatant
was collected and stored at ꢀ70 °C for use.
Plaque Reduction Assay The assay followed procedures described pre-
viously.35) Vero cells (3.5ꢅ105/dish) were overlaid with test compounds
(100 mM) and 100 plaque forming units (PFU) of HSV-1 were added to each
dish. The viruses were adsorbed for 1 h at 37 °C and 1% methylcellulose was
added to each well. After 5 d, the virus plaques formed in Vero cells were
counted by crystal violet staining. The activities of test compounds and
acyclovir for inhibition of plaque formation were calculated.
syrup (90 g). The acidic water-soluble part was neutralized with NH4OH(aq)
,
partitioned with CHCl3, and afforded alkaloidal layer (18 g, HCA). The
HCC layer was eluted with step gradient mixtures of CHCl3 and CH3OH
(29 : 1 to 0 : 1) to afford nine fractions. Fraction 2 was chromatographed over
silica gel column chromatography using CHCl3–CH3OH (99 : 1 to 0 : 1) as
step gradient mixtures as eluents and further purified by repeated column
chromatography to give successively 4 (3.3 mg), 9 (2.5 mg), 33 (4.7 mg), and
a mixture of 35 and 36 (2.1 mg). Fraction 3 was chromatographed on silica
gel and eluted with CHCl3–MeOH (19 : 1) to give 10 (3.8 mg). Fraction 4
was further subjected to column chromatography over silica gel using step-
wise gradients of diisopropyl ether–acetone (34 : 1 to 0 : 1) and then was fur-
ther isolated on the chromatography to afford 3 (4.1 mg), 5 (4.8 mg), 13
(1.4 mg), and 16 (3.7 mg). Fraction 5 was chromatographed on silica gel
eluting with step gradient mixtures of diisopropyl ether–CH3OH (5 : 1 to
0 : 1) and then purified by preparative thin-layer chromatography to afford 11
(2.1 mg). Fraction 6 was purified on silica gel column using stepwise gradi-
ents of CHCl3–MeOH (6 : 1 to 0 : 1) as eluents to produce 8 (1.2 mg) and 38
(29.0 mg). Fraction 8 was separated on a silica gel column chromatography
using CHCl3–MeOH–H2O (39 : 1 : 0.1 to 0 : 1 : 0.1) as step gradient mixtures
as eluents to occur the white precipitate, which was recrystallized by
CH3OH to yield 25 (2.1 g). The HCA layer (18 g) was chromatographed on a
silica gel column eluting with step gradients of CHCl3–CH3OH (99 : 1 to
0 : 1) as eluents to give nine fractions. Fraction 2 was separated on a silica
gel column chromatography and further purified by preparative TLC with n-
hexane–ethyl acetate (9 : 1) to obtain 29 (2.3 mg) and 30 (1.2 mg). Purifica-
tion of fraction 6 on a silica gel column chromatography eluting with a step
gradient of diisopropyl ether–ethyl acetate (14 : 1 to 1 : 1) as eluents and fur-
ther separated by preparative TLC to obtain 34 (0.9 mg). Fraction 7 was sub-
jected to column chromatography over a silica gel using a stepwise gradient
of n-hexane–ethyl acetate (1 : 1 to 0 : 1) as eluents and then was further puri-
fied on the chromatography to afford 7 (1.8 mg) and 21 (1.2 mg). Purifica-
tion of the fraction 8 by silica gel with n-hexane–ethyl acetate (1 : 1 to 0 : 1)
as step gradient mixtures as eluents and then purified by preparative thin-
layer chromatography with CHCl3–MeOH (9 : 1) to afford 15 (2.1 mg), 31
(2.5 mg), and 28 (2.4 mg).
Antioxidant Assay The antioxidant assay was based on methods re-
ported by Mellors and Tappel.36) The percentage values of inhibition were
recorded after incubating for 30 min.
The n-BuOH layer (100 g) was chromatographed over reversed-phase Di-
aion HP-20 gel using H2O–CH3OH as step gradients, and afforded seven
fractions. Fraction 2 was subjected to silica gel column chromatography
using diisopropyl ether–CH3OH (5 : 1 to 0 : 1) as step gradient mixtures as
eluents to afford 19 (7.5 mg). Fraction 3 was purified on a silica gel column
using CHCl3–CH3OH (7 : 1) as step gradients as eluent to yield 32 (1.7 mg).
Fraction 4 was separated on a silica gel column chromatography with
CHCl3–CH3OH–H2O (5 : 1 : 0.1) and further purified by preparative TLC to
obtain successively 17 (2.0 mg), 22 (4.2 mg), 23 (5.2 mg), 24 (3.0 mg) and
37 (6.0 mg). Fraction 5 was separated using a silica gel column with step
gradients of diisopropyl ether–CH3OH–H2O (5 : 1 : 0.1 to 0 : 1 : 0.1) as eluent
to give four fractions. Fraction 5-2 occurring the white precipitate was re-
crystallized by CH3OH to yield 26 (0.9 g). The subfraction 5-3 was sepa-
rated on a silica gel column chromatography and further purified by prepara-
tive TLC with CHCl3–CH3OH–H2O (7 : 1 : 0.1) to give 14 (1.8 mg), 20
(1.9 mg), and 2 (2.3 mg). Fraction 6 was subjected to column chromatogra-
phy over a silica gel using stepwise gradients of diisopropyl ether–CH3OH–
H2O (12 : 1 : 0.1 to 0 : 1 : 0.1) as eluents and then was further purified by
preparative TLC with CHCl3–CH3OH–H2O (4 : 1 : 0.1) to afford 27 (6.0 mg),
18 (2.1 mg), and 1 (2.8 mg).
Antityrosinase Assay The antityrosinase assay was based on the
method of Bernard and Berthon.37)
Acknowledgements The authors are grateful for financial support from
the National Science Council, Taiwan, Republic of China (NSC 96-2628-M-
006-002) awarded to T. S. Wu.
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Houttuynoside A (1): Colorless syrup; [a]D25 ꢀ21.0° (cꢁ0.06, MeOH);
UV (MeOH) lmax (log e) 320 (2.54), 257 (2.54), 211 (3.51) nm; IR (KBr)
n
max 3392 (OH), 1688 (CO) cmꢀ1; 1H-NMR (acetone-d6, 300 MHz) d: 10.37
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2), 7.33 (1H, dd, Jꢁ9.0, 2.9 Hz, H-6), 6.90 (2H, d, Jꢁ8.6 Hz, H-3ꢃ, -5ꢂ),
6.79 (1H, d, Jꢁ9.0 Hz, H-5), 4.90 (1H, d, Jꢁ7.2 Hz, H-1ꢃ), 4.70 (1H, dd,
Jꢁ11.7, 1.5 Hz, H-6ꢃ), 4.33 (1H, dd, Jꢁ11.7, 7.2 Hz, H-6ꢃ), 3.84 (3H, s,
OCH3-7), 3.82 (1H, m, H-5ꢃ), 3.58—3.46 (3H, m, H-2ꢃ, -3ꢃ, -4ꢃ); 13C-NMR
(acetone-d6, 100 MHz) d: 170.2 (C-7), 165.8 (C-7ꢂ), 162.1 (C-4ꢂ), 157.1 (C-
2), 150.3 (C-1), 131.8 (C-2ꢂ, -6ꢂ), 126.3 (C-4), 121.7 (C-1ꢂ), 118.1 (C-3),
117.6 (C-6), 115.3 (C-3ꢂ, -5ꢂ), 112.3 (C-5), 102.4 (C-1ꢃ), 77.1 (C-3ꢃ), 74.5
(C-5ꢃ), 73.9 (C-2ꢃ), 70.9 (C-4ꢃ), 64.0 (C-6ꢃ), 52.2 (OCH3-7); FAB-MS m/z:
451 [MꢆH]ꢆ; HR-FAB-MS m/z: 451.1244 [MꢆH]ꢆ (Calcd for C21H23O11,
451.1240).
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