Bioactive norlignan glucosides from Curculigo capitulata

Article abstract of DOI:10.1021/np9604902

Chemical investigation of Curculigo capitulata yielded two new norlignans, (+)-(1R,2S)- and (-)-(1S,2S)-1-O-butylnyasicosides (1, 2), and the known nyasicoside (3) from the BuOH-soluble fraction of the rhizomes. An alternative study devoid of n-BuOH yielded two additional novel norlignans, 3''-dehydroxynyasiceside (4) and 1-O-methylnyasicoside (5), in addition to 3. The pharmacological studies indicated that 1 and 3 possessed potent activity against ouabain-induced arrhythmia in the heart preparations of guinea pig.

Full text of DOI:10.1021/np9604902

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76
J . Nat. Prod. 1997, 60, 76-80
Bioa ctive Nor lign a n Glu cosid es fr om Cu r cu ligo ca pitu la ta
Wen-Liang Chang,† Ming-J ai Su,‡ and Shoei-Sheng Lee*,†
School of Pharmacy and Institute of Pharmacology, College of Medicine, National Taiwan University, 1 J en-Ai Road,
Section 1, Taipei 100, Taiwan, Republic of China
Received May 28, 1996X
Chemical investigation of Curculigo capitulata yielded two new norlignans, (+)-(1R,2S)- and
(-)-(1S,2S)-1-O-butylnyasicosides (1, 2), and the known nyasicoside (3) from the BuOH-soluble
fraction of the rhizomes. An alternative study devoid of n-BuOH yielded two additional novel
norlignans, 3′′-dehydroxynyasicoside (4) and 1-O-methylnyasicoside (5), in addition to 3. The
pharmacological studies indicated that 1 and 3 possessed potent activity against ouabain-
induced arrhythmia in the heart preparations of guinea pig.
Curculigo capitulata (Lour.) O. Kuntze (Amarylli-
daceae), alias Curculigo recurvata, is widely distributed
in southern and southwestern China, Malaysia, India,
Australia, and Taiwan. This folk medicine has been
used as a tonic and in the treatment of dysmenorrhea
and rheumatism.1 Recent studies have revealed that
this plant is rich in a novel acetylenic norlignan,
nyasicoside (3).2 This compound contains a (1R)-1-
hydroxycatechol moiety and might possess biological
activity related to (-)-epinephrine, which has a similar
skeleton. To evaluate this proposal, we reinvestigated
this plant and report here the outcome of this study.
F igu r e 1. Major HMBC correlations of 1.
and 3.35 (m, 2H, H-1), clarified by a COSY-45 spectrum.
Except for this difference, both spectra are closely
similar to that of 3 (Table 1). For instance, 1 displayed
signals for two ABX systems belonging to the aromatic
protons, protons of a â-glucosyl moiety (δH-1 4.57, d, J
) 7.8 Hz; δH-2 3.30, δH-3 3.40, δH-4 3.35, δH-5 3.40, δH-6
3.64 and 3.82), and four aliphatic protons at δ 4.49 (d,
H-1), 4.10 (m, H-2), 2.30 (dd, H-3), and 2.67 (dd, H-3).
These assignments were made by analyzing the COSY-
45 spectrum, incorporating HMQC data. The placement
of 1-O-butyl and 2-O-â-Glc was made from the observa-
tion of the three-bond coupling of H-1 to C-1 of the butyl
group, anomeric proton to C-2, and H-2 to the anomeric
carbon in the HMBC spectrum (Figure 1). These data
and the optical rotation, [R]23D +29.0° for 1 and -41.0°
for 2, suggested that 1 and 2 are diastereoisomers.
Resu lts a n d Discu ssion
The EtOH extract of the rhizome was partitioned into
fractions soluble in n-hexane, CHCl3, n-BuOH, and H2O.
From the n-BuOH-soluble fraction, three norlignans,
1-3, were isolated by the combination of Amberlite
XAD-2 and low-pressure RP-8 column chromatography.
Among them, 3 was identified as nyasicoside by com-
paring its physical data with those previously reported.2
The stereochemistry for 1 and 2 was elucidated by
examination of their CD spectra. It has been estab-
lished that the CD spectrum of (1R,2S)-nyasicoside (3)
displays two positive Cotton effects near 250 nm and
280 nm.3 The CD curve of 1 being almost superimpos-
able to 3 suggested 1 to be (1R,2S)-1-O-butylnyasicoside.
Nevertheless, the CD curve of 2 showing two negative
Cotten effects might indicate (1S,2S)-stereochemistry.
Enzymatic hydrolysis of 1-3 with â-glucosidase in
acetate buffer solution (pH ) 5.5)2 gave the correspond-
ing aglycons 6-8, respectively. The superimposable CD
curves and similar 1H-NMR data between 6 and 8
(Table 1) supported 6 to be (1R,2S)-1-O-butylnyasicol
and confirmed 1 to be 1-O-butylnyasicoside. Because
Compounds 1 and 2 have the same molecular formula
C27H34O11 (negative FAB [M - H]- m/z 533), being 56
amu more than that of 3. This additional molecular
weight corresponds to a butyl group, evidenced in the
1H-NMR spectra of the butoxyl signals at δ 0.88 (t, 3H,
J ) 7.3 Hz, H-4), 1.37 (m, 2H, H-3), 1.54 (m, 2H, H-2),
1
the optical rotation ([R]25D +3.8°, 6; +35.0°, 7) and H-
NMR data of 6 and 7 are different, both compounds are
diastereoisomers. However, the CD curve of 7 being a
mirror image of 6 would indicate that the chromophore
substitution at C-1 chirality plays the dominant role in
determining the Cotton effect in the CD spectrum like
that observed in flavanones and 3-hydroxyflavanones.4
* To whom correspondence should be addressed. Phone/Fax: (886)-
2-391-6127. E-mail: shoeilee@ntumc1.mc.ntu.edu.tw.
† School of Pharmacy.
‡ Institute of Pharmacology.
X Abstract published in Advance ACS Abstracts, J anuary 15, 1997.
S0163-3864(96)00490-9 CCC: $14.00
© 1997 American Chemical Society and American Society of Pharmacognogy

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Glucosides from Curculigo
Ta ble 1. 1H-NMR Data for Compounds 1-5 (δ/ppm, J in Hz) in CD3OD
J ournal of Natural Products, 1997, Vol. 60, No. 2 77
proton
1
2
3
4
5
1
2
3
4.49 d (5.6)
4.49 d (7.3)
4.05 m
2.54 dd (4.9, 17.1)
2.74 dd (6.9, 17.1)
6.87 d (1.2)
4.65 d (7.3)
4.01 m
2.30 dd (5.8, 17.2)
2.57 dd (4.5, 17.2)
6.90 d (1.7)
4.65 d (7.3)
4.01 m
2.32 dd (4.5, 17.3)
2.58 dd (5.5, 17.3)
6.90 d (1.6)
4.35 (d, 6.3)
4.10 m
2.27 dd (5.6, 17.2)
2.66 dd (4.9, 17.2)
6.85 d (1.8)
4.10 ma
2.30 dd (6.1, 17.0)
2.67 dd (5.1, 17.0)
6.86 d (1.6)
2′
5′
6.74 d (8.0)
6.73 d (8.0)
6.73 d (8.0)
6.74 d (8.1)
6.76 d (8.0)
6′
2′′
6.71 dd (1.6, 8.0)
6.83 d (1.9)
6.72 dd (1.2, 8.0)
6.81 d (1.8)
6.74 dd (1.7, 8.0)
6.81 d (1.9)
6.77 dd (1.6, 8.1)
7.22 d (8.6)
6.75 dd (1.8, 8.0)
6.82 d (1.9)
3′′
6.69 d (8.6)
5′′
6.67 d (8.2)
6.65 d (8.2)
6.65 d (8.2)
6.69 d (8.6)
6.66 d (8.1)
6′′
6.76 dd (8.2, 1.9)
6.75 dd (8.2, 1.9)
6.77 dd (1.9, 8.2)
7.22 d (8.6)
6.72 dd (8.1, 1.9)
1-O-butyl
1
3.35 m
3.35 m
2
1.54 m
1.50 m
3
1.37 m
1.37 m
4
0.88 t (7.3)
0.85 t (7.2)
1-OMe
3.24 s
2-O-Glc
1
2
3
4
5
6
4.57 d (7.7)
3.30 m
3.40 m
3.35 m
3.40 m
4.53 d (7.8)
3.30 m
3.40 m
3.35 m
3.40 m
4.61 d (7.6)
3.30 m
3.40 m
3.35 m
3.40 m
4.61 d (7.6)
3.30 m
3.40 m
3.35 m
3.40 m
4.59 d (7.6)
3.30 m
3.40 m
3.35 m
3.40 m
3.64 dd (5.4, 11.8)
3.82 dd (2.0, 11.8)
3.60 dd (5.3, 11.8)
3.79 dd (1.8, 11.8)
3.68 dd (5.1, 11.8)
3.86 dd (2.0, 11.8)
3.69 dd (5.0, 11.8)
3.87 dd (1.4, 11.8)
3.65 dd (5.4, 12.0)
3.86 dd (2.2, 12.0)
a
Data with multiplicity “m” were overlapped or poorly resolved signals whose chemical shifts were assigned from COSY-45 or HMQC
spectra.
Ta ble 2. 13C-NMR Assignments for Compounds 1-5 (δ/ppm)a
Hence, 7 is (1S,2S)-1-O-butylnyasicol, and 2 is (1S,2S)-
1-O-butylnyasicoside.
in CD3OD
carbon
1
2
3
4
5
Another extraction and separation procedure avoiding
n-BuOH was undertaken. The EtOH extract was
divided into fractions soluble in CHCl3 and H2O. Sepa-
ration of H2O-soluble fraction via similar methods as
indicated above yielded 3 as the major component
together with two novel norlignans 4 and 5. Compounds
1 and 2 were not isolated, nor detected, by RP-8 TLC.
Thus, these two compounds may have been artifacts
produced by isolation utilizing BuOH, although the
exposure of 3 to BuOH at pH 3.5 for 3 days at 50 °C
and for one month at 25 °C failed to produce either 1 or
2.
1
2
3
4
5
83.9 d
80.0 d
22.5 t
84.8 s
83.6 s
131.4 s
83.9 d
81.4 d
21.8 t
85.2 s
83.4 s
131.6 s
76.4 d
82.5 d
22.7 t
84.4 s
83.7 s
133.3 s
76.5 d
82.6 d
22.8 t
84.9 s
83.5 s
133.3 s
85.9 d
79.7 d
22.4 t
84.5 s
83.8 s
130.6 s
1′
2′
116.2 d 116.1 d 115.6 d
116.1 d 116.06 d
3′
4′
146.0 s
146.2 s
145.9 s
146.0 s
146.1 s
146.2 s
146.1 s
146.2 s
146.0 s
146.4 s
5′
6′
1′′
2′′
3′′
4′′
115.9 d 115.8 d 116.08 d 115.6 d 116.04 d
120.7 d 120.7 d 120.1 d 120.1 d 120.9 d
116.1 s 116.2 s 116.05 s 115.8 s 116.1 s
119.5 d 119.5 d 119.5 d
134.0 d 119.5 d
116.2 d 146.3 s
146.1 s
146.9 s
146.0 s
146.9 s
145.9 s
146.8 s
Compound 4 showed [M - H]- at m/z 461.1410 (calcd
461.1448) in the negative HRFABMS for a molecular
formula C23H26O10, being 16 amu fewer than that of 3.
Its 1H-NMR spectrum showed close resemblance to 3
in the aliphatic region but shows one AA′XX′ (δ 6.69
and 7.22, J AX ) 8.6 Hz) and one ABX systems in the
aromatic region instead of two ABX systems as in 3
(Table 1). These two spectral data indicated 4 to be an
analogue of 3 lacking a hydroxy substitution at either
C-3′ or C-3′′. Further comparison of their NMR data
(Tables 1 and 2.) suggested the absence of 3′′-OH in 4.
This suggestion and the similarity of its CD curve to 3
established 4 to be 3′′-dehydroxynyasicoside.
158.4 s
146.9 s
5′′
6′′
116.2 d 116.2 d 116.2 d
124.9 d 124.9 d 124.9 d
116.2 d 116.2 d
134.0 d 124.9 d
1-O-butyl
1
2
3
4
70.2 t
32.9 t
20.4 t
14.2 q
70.1 t
33.0 t
20.5 t
14.3 q
1-OMe
57.2 q
2-O-Glc
1
2
3
4
5
6
103.2 d 103.8 d 103.2 d
103.2 d 102.8 d
74.9 d
77.7 d
71.6 d
78.1 d
62.8 t
74.9 d
77.8 d
71.6 d
78.9 d
62.8 t
74.9 d
77.7 d
71.4 d
78.0 d
62.5 t
74.9 d
77.8 d
71.4 d
78.1 d
62.5 t
74.9 d
77.7 d
71.6 d
78.1 d
62.7 t
Compound 5 showed [M - H]- at m/z 491.1538 (calcd
491.1553) in the negative HRFABMS, suggesting a
molecular formula C24H28O11, being 14 amu more than
a
Multiplicities were obtained from DEPT experiments.
1
that of 3. Its H-NMR spectrum showed close resem-
and HMBC (Figure 1). Among them, C-1′ and C-1′′ of
3 were assigned unambiguously at δ 133.3 and 116.05
from their respective coupling to H-5′ (δ 6.73, d) and
H-5′′ (δ 6.65, d), revising the previous reported data.2
Pharmacological study of 1-5 on rat cardiac tissues
indicated that they had no apparent effect on both
contractile tension and heart rate at the dose range of
0.3 to 30 µM (Table 3). Nevertheless, further study
indicated these compounds were effective to a certain
extent against the arrhythmic effect induced by ouabain
blance to 3 except for an additional MeO singlet at δ
3.24 (Table 1), which reflected in the 13C-NMR a signal
at δ 57.2 (q) (Table 2). These data and a similar CD
curve to that of 3 established 5 to be 1-O-methyl
nyasicoside.
The 1H-NMR data (Table 1) and 13C-NMR data (Table
2) of compounds 1-5 were assigned by using 1-3 as
model compounds whose assignments were made by
analysis of 2D NMR spectra including COSY, HMQC,

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78 J ournal of Natural Products, 1997, Vol. 60, No. 2
Chang et al.
Ta ble 3. Effects of Compounds 1-5 on Contractile Tension and Heart Rate of Rat Cardiac Tissuesa
com p ou n d
concn
assay item
(µM)
1
2
3
4
5
heart rate (RA)
0.3
1
3
10
30
100
100
100
100
100
99.0 ( 1.0b
98.4 ( 1.0c
98.4 ( 1.0c
97.4 ( 1.1d
98.8 ( 1.3b
97.4 ( 2.7
98.5 ( 3.0
98.5 ( 3.0
97.5 ( 2.5
97.5 ( 2.5
98.5 ( 3.0
98.5 ( 3.0
100
99.0 ( 1.0b
99.8 ( 1.4
97.6 ( 3.3
103.0 ( 1.5
103.0 ( 1.5
103.0 ( 1.5
tension (RA)
tension (LA)
tension (RV)
0.3
1
3
10
30
94.0 ( 4.2
91.0 ( 3.2d
89.6 ( 3.2d
86.2 ( 3.2d
83.6 ( 3.4d
95.5 ( 2.7c
94.3 ( 6.6
91.6 ( 5.9b
87.8 ( 7.5c
86.4 ( 8.4c
96.8 ( 2.0c
94.5 ( 4.0b
92.0 ( 2.8d
83.3 ( 8.6c
78.0 ( 9.0d
97.5 ( 2.5
98.3 ( 1.8
94.5 ( 3.4
94.8 ( 5.3
99.0 ( 3.8
99.0 ( 3.8
100.3 ( 4.2
101.7 ( 4.9
0.3
1
3
10
30
98.8 ( 1.3
96.0 ( 2.4c
91.2 ( 4.0d
89.4 ( 6.4c
92.5 ( 7.5
98.8 ( 2.8
95.3 ( 6.8
101.0 ( 10.6
105.0 ( 13.8
103.8 ( 13.1
108.3 ( 8.3
105.8 ( 5.9
104.5 ( 8.7
100.3 ( 10.2
98.0 ( 14.3
106.8 ( 6.8
111.5 ( 11.5
119.3 ( 19.3
116.3 ( 22.9
103.0 ( 1.7
101.3 ( 4.7
102.3 ( 14.8
89.7 ( 30.8
0.3
1
3
10
30
99.0 ( 1.0
95.8 ( 3.1b
96.8 ( 3.1
95.4 ( 6.4
88.2 ( 8.5b
102.0 ( 1.2c
100.0 ( 2.9
100.4 ( 3.3
96.8 ( 3.7
92.3 ( 4.8c
84.8 ( 6.7d
83.6 ( 8.0d
78.2 ( 8.8d
74.6 ( 9.4d
98.4 ( 1.0
99.2 ( 2.7
95.2 ( 3.4
94.2 ( 6.0
106.7 ( 4.1
106.3 ( 9.0
104.3 ( 9.8
99.3 ( 4.8
92.2 ( 4.5c
* Contractions of left atrial (LA) and right ventricular (RV) strips were elicited by electrical stimulations driven at 2 Hz. Spontaneous
contraction of right atria (RA) and heart rate were measured. Mean values (% of control: heart rate 242 ( 7 beats/min; twitch tension
RA 121 ( 10 mg, LA 140 ( 1 mg, RV 225 ( 17 mg) were obtained from four to five experiments, bp < 0.05, cp < 0.01, dp < 0.001,
compared with the respective control by Student’s t-test.
Ta ble 4. Effects of Compounds 1-5 Against Ouabain-Induced
polarimeter; J EOL J MX-HX110 mass spectrometer
(FAB); Bruker AMX-400 spectrometer using solvent
peak (MeOH-d4) as reference standard, 2D NMR spectra
were recorded by using Bruker’s standard pulse pro-
gram in the HMQC and HMBC experiments, ∆ ) 1 s
and J ) 140 Hz and 8 Hz, respectively, the correlation
maps consisted of 512 × 1K data points per spectrum,
each composed of 16 to 64 transients.
Arrhythmia in Guinea Pig’s Heart Preparationsa
com p ou n d
cardiac
tissues
concn.
(µM)
1
2
3
4
5
RA
LA
1
3
10
30
(
-
-
-
-
+
+
(
(
-
+
(
P la n t Ma ter ia l. The rhizomes of C. capitulata
(Lour.) O. Kuntze were collected in November 1993, in
the suburban mountain of Taipei, Taiwan. A specimen
was authenticated by Prof. C.-F. Hsien, Department of
Botany, National Taiwan University. A voucher her-
barium specimen is deposited at the School of Phar-
macy, National Taiwan University.
1
3
10
30
(
++
(
+
-
++
(
(
(
-
RV
1
3
10
30
-
(
-
-
-
-
-
(
-
-
-
-
-
(
Extr a ction a n d Isola tion . The dried powder of the
rhizome (5.10 kg) was extracted with 95% EtOH (7 L ×
5). Concentration of the EtOH extract gave a residue
(678 g) that was soluble in aqueous 80% MeOH solution
(770 mL), and then partitioned with n-hexane (1 L × 3)
to give the n-hexane-soluble fraction (33 g). The aque-
ous 80% MeOH layer was evaporated to remove residual
MeOH, and then distilled H2O (300 mL) was added. This
aqueous solution was partitioned with CHCl3 (1 L × 3)
and n-BuOH (800 mL × 5) to get a CHCl3-soluble (13
g) and an n-BuOH-soluble fraction (620 g). Part of the
n-BuOH-soluble fraction (10.39 g) was passed through
an Amberlite XAD-2 column (200 g) eluted in order with
30%, 50% MeOH in H2O, and MeOH to give a 30%
MeOH fraction (2.72 g), a 50% MeOH fraction (1.96 g),
and a MeOH fraction (0.81 g). The MeOH fraction was
then separated by repeated lobar RP-8 column (E.
Merck, B type) with MeOH-H2O (56:44) and MeOH-
H2O (54:46) as eluent to afford 1 (28 mg) and 2 (20 mg).
Similarly, the 30% MeOH fraction (2.10 g) yielded 3 (280
mg) eluted with MeOH-H2O (3:7).
a
Contractions of left atrial (LA) and right ventricular (RV)
strips were elicited by electrical stimulations dirven at 2 Hz.
Spontaneous contraction of right atria (RA) and heart rate were
measured. Mean values of control are as follows: heart rate 186
( 6 beats/ min; twitch tension RA 336 ( 42 mg, LA 381 ( 48 mg,
and RV 317 ( 49 mg. “-” denotes ineffective in reversion of
cardiac arrhythmia. “(” and “+” denote partially effective in some
or most of the preparations (n g 3), respectively. “++” denotes
that the reversion of cardiac arrhythmia to normal rhythm can
sustain for more than 10 min.
(0.6 µM) in guinea pig’s heart preparations (Table 4).
Of these, compounds 1 and 3 are most potent. In left
atria, these two compounds can normalize completely
the ouabain-induced arrhythmia at dose of 3 µM.
Quinidine, the commonly used antiarrhythmic drug,
exhibits similar activity at dose of 30-60 µM.5 The
mechanism of the antiarrhythmic effect of these com-
pounds remains to be clarified.
Exp er im en ta l Section
Gen er a l Exp er im en ta l P r oced u r es. The physical
data of the isolated compounds were obtained from the
following instruments: Perkin-Elmer 1760-X IR-FT
spectrometer; Hitachi 150-20 UV; J ASCO J -710 spectro-
The dried powder of the rhizome (1.02 kg) of the
second crop of plant materials, collected in the same
place in J anuary 1995, was percolated with 95% EtOH

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Glucosides from Curculigo
J ournal of Natural Products, 1997, Vol. 60, No. 2 79
(7 L × 5). The EtOH extract (110 g) was partitioned
between CHCl3 (1 L × 3) and H2O (1 L) to give a CHCl3-
soluble fraction (8 g). The aqueous layer after removal
of residual CHCl3 via condensation was passed through
an Amberlite XAD-2 column (800 g, × 5) to get a 30%
MeOH fraction (35 g), a 50% MeOH fraction (3.6 g), and
a MeOH fraction (0.98 g). Further separation by a lobar
RP-8 column (B type) eluted with MeOH-H2O (3:7)
yielded 3 (2.04 g, 1.41% w/w), 4 (111 mg), and 5 (47 mg)
from a 4.96-g portion of the 30% MeOH fraction.
(+)-1-O-Bu tyln ya sicosid e (1): amorphous powder;
[R]23D +19.0° (c, 1.0, MeOH); IR (KBr) ν max: 3400,
2960, 2940, 2870, 1600, 1520, 1440, 1360, 1280, 1080,
870, 815, 780 cm-1; UV (MeOH) λ max (log ꢀ) 257 (4.39),
288 (4.07) nm; CD (MeOH) [θ]308 0°, [θ]289 +8380°, [θ]270
+6130°, [θ]249 +20 340°, [θ]233 +3820°, [θ]211 +53 120°;
1H-NMR and 13C-NMR spectral data, see Table 1 and
Table 2; FABMS (neg) m/z [M - H + TG]- 641 (50), [M
- H]- 533 (100), 459 (13), 409 (19), 279 (56).
(-)-1-O-Bu tyln ya sicosid e (2): amorphous powder;
[R]23D -41.0° (c 1.0, MeOH); IR (KBr) ν max 3400, 2960,
2940, 2870, 1600, 1520, 1445, 1360, 1285, 1070, 870,
820, 780 cm-1; UV (MeOH) λ max (log ꢀ) 257 (4.20), 285
(3.98) nm; CD (MeOH) [θ]310 -400°, [θ]287 -5390°, [θ]270
-4250°, [θ]258 -10 720°, [θ]250 -12 480°, [θ]233 -3980°;
1H-NMR and 13C-NMR spectral data, see Table 1 and
Table 2; FABMS (neg) m/z [M - H + TG]- 641 (34), [M
- H]- 533 (79), 389 (100), 279 (50).
Nya sicosid e (3): CD (MeOH); [θ]337 0°, [θ]327 +210°,
[θ]304 +2020°, [θ]300 +2180°, [θ]285 +5100°, [θ]270 +4040°,
[θ]252 +11 420°, [θ]231 +1960°, [θ]210 + 31 570°; 1H-NMR
and 13C-NMR spectral data, see Table 1 and Table 2;
HMBC data, H-2 to C-1, C-4, and Glc C-1, H-3 to C-4,
H-2′ to C-1, C-4′, C-6′, H-5′ to C-1′, C-3′, H-6′ to C-1 and
C-2′, H-2′′ to C-5, C-4′′, and C-6′′, H-5′′ to C-1′′ and C-3′′,
H-6′′ to C-5, Glc H-1 to C-2, Glc H-3 to Glc C-2 and Glc
C-4, Glc H-5 to Glc C-1 and Glc C-3.
and the residue was separated by low pressure column
(RP-8) [MeOH-H2O (30:70)] to give amorphous 6 (2
mg): [R]25D +3.8° (c 0.2, MeOH); UV (MeOH) λ max (log
ꢀ) 257 (4.17), 286 (3.92) nm; CD (MeOH) [θ]328 0°, [θ]319
+318°, [θ]312 0°, [θ]302 +2310°, [θ]284 +6160°, [θ]271
+4750°, [θ]250 +15 360°, [θ]231 +3650°, [θ]211 +37 280°;
1H-NMR (MeOH-d4) δ 6.80 (2H, d, J ) 1.9 Hz, H-2′ and
2′′), 6.74 (1H, d, J ) 8.1 Hz, H-5′), 6.74 (1H, dd, J )
1.9, 8.1 Hz, H-6′′), 6.69 (1H, dd, J ) 1.9, 8.1 Hz, H-6′),
6.66 (1H, d, J ) 8.1 Hz, H-5′′), 4.20 (1H, d, J ) 6.5 Hz,
H-1), 3.75 (1H, m, H-2), 3.35 (2H, m, H-1 of O-Bu), 2.50
(1H, dd, J ) 5.1, 16.8 Hz, H-3), 2.24 (1H, dd, J ) 5.9,
16.8 Hz, H-3), 1.55 (2H, m, H-2 of O-Bu), 1.37 (2H, m,
H-3 of O-Bu), 0.87 (3H, t, J ) 7.4 Hz, H-4 of O-Bu);
FABMS (neg) m/z [M - H]- 371.
(-)-1-O-Bu tyln ya sicol (7). Using the same condi-
tions as in the preparation of 6, 7 (1 mg) was obtained
from hydrolysis of 2 (38 mg). The physical data of 7
are as follows: [R]25D +35.0° (c 0.1, MeOH); UV (MeOH)
λ max (log ꢀ) 257.0 (4.16), 284.6 (3.92) nm; CD (MeOH)
[θ]329 0°, [θ]323 +310°, [θ]313 0°, [θ]288 -3850°, [θ]270 0°,
1
[θ]249 -9340°, [θ]232 -780°; H-NMR (MeOH-d4) δ 6.82
(1H, d, J ) 1.9 Hz, H-2′), 6.81 (1H, d, J ) 1.9 Hz, H-2′′),
6.745 (1H, dd, J ) 1.9, 8.1 Hz, H-6′′), 6.74 (1H, d, J )
8.1 Hz, H-5′), 6.68 (1H, dd, J ) 1.9, 8.1 Hz, H-6′), 6.65
(1H, d, J ) 8.1 Hz, H-5′′), 4.12 (1H, d, J ) 6.3 Hz, H-1),
3.80 (1H, m, H-2), 3.35 (2H, m, H-1 of O-Bu), 2.60 (2H,
d, J ) 6.0 Hz, H-3), 1.52 (2H, m, H-2 of O-Bu), 1.38 (2H,
m, H-3 of O-Bu), 0.88 (3H, t, J ) 7.4 Hz, H-4 of O-Bu);
FABMS (neg) m/z [M - H]- 371.
Nya sicol (8). Using the same conditions as in the
preparation of 6, 8 (9 mg) was obtained from hydrolysis
of 3 (40 mg). The physical data of 8 are as follows:
[R]25D +36.0° (c 1.0, MeOH); UV (MeOH) λ max (log ꢀ)
257.8 (4.33), 283.8 (4.16) nm; CD (MeOH) [θ]320 +270°,
[θ]313 0°, [θ]302 +2190°, [θ]284 +6100°, [θ]270 +4860°, [θ]253
+14 510°, [θ]233 +3160°, [θ]211 +36 820°; 1H-NMR (MeOH-
d4) δ 2.26 (1H, dd, J ) 6.3, 17.0 Hz, H-3), 2.48 (1H, dd,
J ) 4.9, 17.0 Hz, H-3), 3.75 (1H, dt, J ) 5.1, 6.6 Hz,
H-2), 4.52 (1H, d, J ) 6.6 Hz, H-1), 6.65 (1H, d, J ) 8.1
Hz, H-5′′), 6.75 (1H, dd, J ) 1.9, 8.1 Hz, H-6′′ or 6′),
6.80 (1H, d, J ) 1.9 Hz, H-2′′), 6.74 (1H, dd, J ) 1.9,
8.1 Hz, H-6′ or 6′′), 6.72 (1H, d, J ) 8.1 Hz, H-5′), 6.86
(1H, d, J ) 1.9 Hz, H-2′); FABMS (neg) m/z [M - H]-
315.
Assa y on Con tr a ction s a n d Sp on ta n eou sly Bea t-
in g Hea r t Ra te of Ra t Ca r d ia c Tissu es. Right atrial,
left atrial, and right ventricular strips (4 × 6 mm) were
dissected from the hearts of male WKY rats (weighing
250-300 g) and placed in an organ bath containing 10
mL of Tyrode solution gassed with 95% O2 and 5% CO2.
Contractions of electrically driven left atrial and right
ventricular strips and heart rate in spontaneously
beating right atria were measured by the method
described previously.6
3′′-Deh yd r oxyn ya sicosid e (4): amorphous powder;
[R]23D -2.0° (c 1.0, MeOH); UV (MeOH) λ max (log ꢀ)
255 (4.18), 282 (3.80) nm; [R]23D -2.0° (c 1.0, MeOH);
IR (KBr) ν max 3400 (br m, OH), 2950, 1605, 1515, 1450,
1360, 1290, 1085, 1035, 840, 820 cm-1; CD (MeOH) [θ]340
-200°, [θ]322 +150°, [θ]311 -310°, [θ]302 +230°, [θ]300
+220°, [θ]283 +3970°, [θ]268 +2540°, [θ]243 +10 430°,
[θ]226 -850°; [θ]215 +3220°, [θ]207 +15 280°; 1H-NMR and
13C-NMR spectral data, see Table 1 and Table 2;
FABMS (neg) m/z [M - H]- 461 (24), 443 (8), 371 (21),
331 (13), 297 (17), 281 (42), 263 (45), 249 (16), 205 (17),
183 (100), 181 (18), 150 (16), 137 (21).
1-O-Met h yln ya sicosid e (5): amorphous powder;
[R]23D +22.0° (c 1.0, MeOH); IR (KBr) ν max 3400 (br
m, OH), 2940, 1603, 1520, 1445, 1360, 1285, 1070, 820,
780 cm-1; UV (MeOH) λ max (log ꢀ) 257 (4.25), 286 (3.92)
nm; CD (MeOH) [θ]329 0°, [θ]322 +250°, [θ]314 0°, [θ]301
+2110°, [θ]285 +5300°, [θ]272 +4030, [θ]251 +12 030°,
Evau lation of An tiar r h yth m ic Activity on Gu in ea
P ig Hea r t. Cardiac arrhythmia of electrically driven
left atrial or right ventricular strips of guinea pigs were
induced by ouabain (0.6 µM). The antiarrhythmic
activity of compounds 1-5 was tested after arrhythmia
was induced.7
1
[θ]231 +2550°, [θ]210 +32 510°; H-NMR and 13C-NMR
spectra data, see Table 1 and Table 2; FABMS (neg) m/z
[M - H]- 491 (100), 470 (15), 459 (25), 390 (22), 327
(48), 297 (21), 279 (79), 255 (24), 243 (22).
Hyd r olysis of Nor lign a n s. (+)-1-O-Bu tyln ya sicol
(6). â-Glucosidase (15 mg) was added to the solution
(7.5 mL) of 1 (40 mg) in acetate buffer (pH 5.5).2 The
solution was maintained at 37 °C for 4 days and
extracted with EtOAc (40 mL × 3). The combined
organic layer was dried over Na2SO4 and evaporated,
Ack n ow led gm en t. The authors are grateful to the
National Science Council, Taiwan, Republic of China,
for financial support of this work under the grant
NSC86-2314-B-002-081.

+
+
80 J ournal of Natural Products, 1997, Vol. 60, No. 2
Chang et al.
(4) Gaffield, W. Tetrahedron 1970, 26, 4093-4108.
Refer en ces a n d Notes
(5) Su, M. J . unpublished data.
(1) Chiu, N. Y.; Chang, K. H. The Illustrated Medicinal Plants of
Taiwan; Southern Materials Center: Taipei, 1986; Vol. 2, p 276.
(2) Galeffi, C.; Multari, G.; Msonthi, J . D.; Nicoletti, M.; Marini-
Bettolo, G. B. Tetrahedron 1987, 43, 3519-3522.
(3) Chifurdera, K.; Messana, I.; Galeffi, C.; De Vicente, Y. Tetra-
hedron 1991, 47, 4369-4374.
(6) Su, M. J .; Chang, G. J .; Kuo, S. C. Br. J . Pharmcol. 1993, 110,
310-316.
(7) Sekiya, A.; Vaughan Williams, E. M. Br. J . Pharmcol. 1963, 21,
462-472.
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