New cyanoglycosides, hydracyanosides D, E, and F, from the leaves of Hydrangea macrophylla

Article abstract of DOI:10.3987/COM-09-11886

Three new cyanoglycosides named hydracyanosides D (1), E (2), and F (3) were isolated from the leaves of Hydrangea macrophylla cultivated in China together with 17 known constituents including hydracyanoside A (4). Their structures were elucidated on the basis of chemical and physicochemical evidence.

Full text of DOI:10.3987/COM-09-11886

HETEROCYCLES, Vol. 81, No. 4, 2010
909
HETEROCYCLES, Vol. 81, No. 4, 2010, pp. 909 - 916. © The Japan Institute of Heterocyclic Chemistry
Received, 14th December, 2009, Accepted, 8th February, 2010, Published online, 9th February 2010
DOI: 10.3987/COM-09-11886
NEW CYANOGLYCOSIDES, HYDRACYANOSIDES D, E, AND F, FROM
THE LEAVES OF HYDRANGEA MACROPHYLLA
Zhibin Wang,a,b Seikou Nakamura,a Hisashi Matsuda,a Lijun Wu,b and Masayuki
Yoshikawaa,*
aKyoto Pharmaceutical University, Misasagi, Yamashina-ku, Kyoto 607-8412,
Japan
bSchool of Traditional Chinese Materia Medica, Shenyang Pharmaceutical
University, Shenyang 110016, China
Abstract —Three new cyanoglycosides named hydracyanosides D (1), E (2), and
F (3) were isolated from the leaves of Hydrangea macrophylla cultivated in China
together with 17 known constituents including hydracyanoside A (4). Their
structures were elucidated on the basis of chemical and physicochemical evidence.
In the course of our characterization studies on bioactive constituents from Hydrangea species,1-6 we have
reported the isolation and absolute stereostructure elucidation of three cyanogenic glycosides,
hydracyanosides A (4), B, and C from H. macrophylla (Thunb.) Ser. (Saxifragaceae).1 As a continuing
study on the leaves of H. macrophylla, we have isolated three new cyanoglycosides named
hydracyanosides D (1), E (2), and F (3) together with 17 known constituents. In this paper, we describe
the isolation and structure elucidation of these three new constituents.
The leaves of H. macrophylla were
finely cut and treated with MeOH to
furnish a MeOH extract (26.0%).
The MeOH extract was partitioned
into an EtOAc–H2O (1:1, v/v)
mixture to furnish an EtOAc-soluble
fraction (8.4%) and an aqueous
phase. The aqueous phase was
further extracted with n-BuOH to give an n-BuOH- and a H2O-soluble fraction (6.5% and 11.1%,
respectively).1 The n-BuOH-soluble fraction was separated by normal- and reversed-phase column
chromatography, and finally HPLC to give hydracyanosides D (1, 0.00071%), E (2, 0.00020%), F (3,
0.00023%), together with hydracyanoside A (4, 0.09%),1 (2R)-taxiphyllin (5, 0.00028%),7,8 tachioside (6,
0.00061%),9 isotachioside (7, 0.00072%),9 3-(ꢀ-D-glucopyranosyloxy)-4-methoxybenzaldehyde (8,
0.00093%),10 2-phenylethyl-ꢀ-D-glucopyranoside (9, 0.00032%),11 salidroside (10, 0.00014%),12 icariside

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HETEROCYCLES, Vol. 81, No. 4, 2010
F2 (11, 0.00022%),13 loganin (12, 0.0015%),14 8-epi-loganin (13, 0.0011%),15 secoxyloganin (14,
0.00070%),16 vogeloside (15, 0.0023%),17 epi-vogeloside (16, 0.00038%),17 thymidine (17,
0.00037%),18,19 adenosine (18, 0.00055%),20 (–)-methyl shikimate (19, 0.00023%),21 Z-hex-3-en-1-ol ꢀ-
D-xylopyranosyl(1-6)-ꢀ-D-glucopyranoside (20, 0.00051%)22 (Chart 1, 2).
Hydracyanoside D (1) was isolated as a white powder with
23
negative optical rotation ([a]D
–111.6° in MeOH). The
molecular formula C32H41NO17 of 1 was clarified from the
positive-ion FABMS [m/z 734 (M+ Na)+] and by HRFABMS
measurement. The IR spectrum showed the presence of cyano
group (2365 cm-1), ester (1701 cm-1), olefin (1655 cm-1), and an
oligoglycoside structure (3420 and 1078 cm-1). Acid hydrolysis of
1 with 1 M HCl liberated D-glucose, which was identified by
1
HPLC analysis using an optical rotation detector.23,24 The H-
(CD3OD) and 13C-NMR (Table 1) spectra of 1, which were
assigned by various NMR experiments,25 showed signals
assignable to a methoxy group [ꢀ 3.87 (3H, s)], a carbomethoxy
group [ꢀ 3.70 (3H, s)], a methine bearing a cyano functional group
[ꢀ 5.60 (1H, s, 2-H)], four olefinic protons [ꢀ 5.24 (1H, br d, J = 11.0 Hz, 10'''a-H), 5.30 (1H, br d, J =

HETEROCYCLES, Vol. 81, No. 4, 2010
911
Table 1. 13C-NMR data for 1
17.8 Hz, 10'''b-H), 5.73 (1H, ddd, J = 8.2, 11.0, 17.8 Hz,
8'''a-H), 7.45 (1H, s, 3'''-H)], an aromatic ring [ꢀ 6.95 (1H,
dd, J = 2.1, 8.3 Hz, 6'-H), 6.96 (1H, d, J = 8.3 Hz, 5'-H),
7.00 (1H, d, J = 2.1 Hz, 2'-H)], two ꢁ-D-glucopyranosyl
moieties [ꢀ 4.40 (1H, d, J = 8.0 Hz, 1''-H), 4.67 (1H, d, J =
7.6 Hz, 1''-H)], and a cyano group (ꢀc 119.4, 1-C). The
double quantum filter correlation spectroscopy (DQF
COSY) experiment on 1 indicated the presence of partial
structures written in bold lines, and in the heteronuclear
multiple bond connectivity spectroscopy (HMBC)
experiment, long-range correlations were observed
between the following protons and carbons: 2-H and 1, 1'-
C; 2'-H and 1', 4'-C; 5'-H and 3'-C; 6'-H and 4'-C; 1''-H and
2-C; 4''-H and 7'''-C; 6''-H and 7'''-C; 1'''-H and 3'''-C; 3'''-H
and 11'''-C; 5'''-H and 7'''-C; 6'''-H and 7'''-C; 7'''-H and 4'',
Position
Position
1
2
1'
2'
3'
4'
5'
6'
119.4
69.1
127.3
115.7
148.3
150.5
112.6
120.7
56.5
103.1
75.6
74.5
81.6
67.9
69.2
ꢀ
1'''
3'''
4'''
5'''
6'''
7'''
8'''
9'''
10'''
11'''
COOCH3
1''
2''
3''
4''
5''
6''
97.7
153.7
111.5
29.6
35.1
102.7
135.8
45.4
119.9
169.3
51.9
100.0
74.7
78.0
4'-OCH3
1''
2''
3''
4''
5''
6''
71.6
78.4
62.8
ꢀ
Measured in CD3OD at 150 MHz
6''-C; -OCH3 and 4'-C; -COOCH3 and 11'''-C (Figure 1). Furthermore, the NOESY spectrum showed
NOE correlations between the following proton pairs (4''-H and 6''ꢀ, 7'''-H; 6''ꢀ -H and 7'''-H), so that the
stereostructure of 1 was characterized. Finally, methanolysis of 1 with mild conditions was carried out to
give hydracyanoside A (4)1 and secoxyloganin dimethylacetal.17 Consequently, the structure of
hydracyanoside D (1) was determined as shown.
Table 2. 13C-NMR data for 2
24
Hydracyanoside E (2), [ꢂ]D –29.4°
Position
Position
(MeOH), was isolated as a white
powder. The IR spectrum of 2 showed
absorption bands at 3570, 2257, and
1074 cm–1 ascribable to hydroxyl,
cyano, and ether functional groups.
The molecular formula C15H19NO8
was determined from the positive-ion
FABMS at m/z 364 (M+Na)+ and by
1
2
1'
2'
3'
4'
5'
6'
119.8
18.1
1''
2''
3''
4''
5''
6''
104.3
75.1
77.9
71.4
78.2
62.5
109.9
152.5
101.7
152.0
140.9
121.1
56.7
4'-O-CH3
Measured in CD3OD at 150 MHz
HRFABMS measurement. Acid hydrolysis of 2 liberated D-glucose, which was identified by HPLC
1
13
analysis using an optical rotation detector.23,24 The H- (CD3OD) and C-NMR (Table 2) spectra25 of 2
indicated the presence of a methoxy group [ꢀ 3.81 (3H, s)], a methylene [ꢀ 3.65 (1H, s, 2-H2)], an
aromatic ring [ꢀ 6.54 (1H, s, 3'-H), 7.13 (1H, s, 6'-H)], a ꢁ-D-glucopyranosyl moiety [ꢀ 4.72 (1H, d, J =
7.6 Hz, 1''-H)], and a cyano group (ꢀc 119.8, 1-C). Next, long-range correlations in the HMBC
experiment were observed between the following proton and carbon: 2-H2 and 1, 1', 2', 6'-C; 3'-H and 1',
2', 5'-C; 6'-H and 2, 2', 4'-C; 1''-H and 5'-C; -OCH3 and 4'-C (Figure 2). Furthermore, the NOESY
spectrum showed NOE correlations between the following proton pairs (1''-H and 6'-H; -OCH3 and 3'-H).
On the basis of this evidence, the structure of 2 was elucidated as shown.

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HETEROCYCLES, Vol. 81, No. 4, 2010
25
Hydracyanoside F (3), [ꢀ]D –106.2° (MeOH), was isolated
as a white powder. The IR spectrum showed the presence of
cyano group (2361 cm-1), ester (1719 cm-1), olefin (1655
cm-1), and a glycoside structure (3420 and 1074 cm-1). The
molecular formula C17H21NO9 was determined from the
positive-ion FABMS at m/z 406 (M+Na)+ and by
HRFABMS measurement. Acid hydrolysis of 3 liberated D-
glucose.23,24 The H- (CD3OD) and C-NMR (Table 3)
spectra25 of 3 indicated the presence of a methine bearing
a cyano functional group [ꢁ 5.59 (1H, dd, J = 2.0, 5.5 Hz,
7-H)], four olefinic protons [ꢁ 5.31 (1H, dd, J = 2.1, 10.3
Hz, 10a-H), 5.36 (1H, dd, J = 2.1, 17.3 Hz, 10b-H), 5.54
(1H, ddd, J = 9.7, 10.3, 17.3 Hz, 8-H), 7.70 (1H, br s, 3-
H)], a ꢂ-D-glucopyranosyl moiety [ꢁ 4.75 (1H, d, J = 7.6
Hz, 1'-H)], and a cyano group (ꢁc 118.0). The proton and
carbon signals in the 1H- and 13C-NMR of 3 were similar
to those of epi-vogeloside (16)17 except for the signals
around the 7-position. The connectivity of a sugar part in
3 was characterized by HMBC experiment, which
1
13
Table 3. 13C-NMR data for 3
Position
Position
1
3
4
98.7
156.0
103.7
25.6
1'
2'
3'
4'
5'
6'
100.6
74.6
78.1
71.5
78.5
62.7
5
6
28.4
7
66.8
8
9
132.8
43.1
10
11
CN
121.8
165.0
118.0
Measured in CD3OD at 150 MHz
showed long-range correlations between the 1'-proton and the 1-carbon (Figure 3). Furthermore, the
NOESY spectrum showed NOE correlations between the following proton pairs (1ꢀ-H and 8-H; 5-H and
6ꢁ, 9-H; 6ꢁ-H and 7-H; 6ꢀ-H and 7-H). On the basis of this evidence, the structure of 3 was elucidated as
shown.
EXPERIMENTAL
The following instruments were used to obtain physical data: specific rotations, Horiba SEPA-300 digital
polarimeter (l = 5 cm); UV spectra, Shimadzu UV-1600; IR spectra, Shimadzu FTIR-8100
1
spectrophotometer; FABMS and high-resolution FABMS, JEOL JMS-SX 102A mass spectrometer; H-
NMR spectra, JEOL EX-270 (270 MHz), JNM-LA500 (500 MHz), and JEOL ECA-600K (600 MHz)
13
spectrometers; C-NMR spectra, JEOL EX-270 (68 MHz), JNM-LA500 (125 MHz), and JEOL ECA-
600K (150 MHz) spectrometers with tetramethylsilane as an internal standard; HPLC detector, Shimadzu
RID-6A refractive index and SPD-10Avp UV-VIS detectors; and HPLC column, Cosmosil 5C18-MS-II
(250 x 4.6 mm i.d.) and (250 x 20 mm i.d.) columns were used for analytical and preparative purposes,
respectively. The following experimental materials were used for chromatography: normal-phase silica
gel column chromatography, Silica gel BW-200 (Fuji Silysia Chemical, Ltd., 150–350 mesh); reversed-
phase silica gel column chromatography, Chromatorex ODS DM1020T (Fuji Silysia Chemical, Ltd.,
100–200 mesh); TLC, precoated TLC plates with Silica gel 60F254 (Merck, 0.25 mm) (ordinary phase)
and Silica gel RP-18 F254S (Merck, 0.25 mm) (reversed phase); reversed-phase HPTLC, precoated TLC

HETEROCYCLES, Vol. 81, No. 4, 2010
913
plates with Silica gel RP-18 WF254S (Merck, 0.25 mm); and detection was achieved by spraying with 1%
Ce(SO4)2–10% aqueous H2SO4 followed by heating.
Plant Material
The fresh leaves of H. macrophylla, which were cultivated in Sichuan province of China, were collected
in 2008. A voucher of the plant is on file in our laboratory (Phamacognosy-2008-HM).
Isolation of Constituents from the Leaves of H. macrophylla
The fresh leaves (2.2 kg) of H. macrophylla cultivated in Sichuan province of China were finely cut and
extracted with MeOH under reflux to provide a MeOH extract (573 g, 26.0%). The MeOH extract (563 g)
was partitioned into an EtOAc–H2O (1:1, v/v) mixture to furnish an EtOAc-soluble fraction (182 g, 8.4%)
and an aqueous phase. The aqueous phase was further extracted with n-BuOH to give an n-BuOH-soluble
fraction (140 g, 6.5%) and a H2O-soluble fraction (240 g, 11.1%). The n-BuOH-soluble fraction (140 g)
was subjected to ordinary-phase silica gel column chromatography {3.0 kg, CHCl3 ꢀ CHCl3–MeOH–
H2O [(30:3:1, v/v/v, lower layer) ꢀ (10:3:1, v/v/v, lower layer) ꢀ (7:3:1, v/v/v, lower layer) ꢀ (6:4:1,
v/v/v)] ꢀ MeOH} to give five fractions [Fr. 1 (20.0 g), Fr. 2 (10.9 g), Fr. 3 (60.3 g), Fr. 4 (30.7 g), Fr. 5
(12.7 g)]. Fraction 1 (20.0 g) was subjected to reversed-phase silica gel column chromatography [500 g,
MeOH–H2O (15:85 ꢀ 25:75 ꢀ 45:55 ꢀ 65:35 ꢀ 85:15, v/v) ꢀ MeOH ꢀ CHCl3] to afford six
fractions [Fr. 1-1, Fr. 1-2 (1.0 g), Fr. 1-3 (4.2 g), Fr. 1-4 (1.2 g), Fr. 1-5, Fr. 1-6]. Fraction 1-2 (1.0 g) was
subjected to HPLC [MeOH–H2O (15:85, v/v)] to afford thymidine (17, 8.1 mg, 0.00037%). Fraction 1-3
(4.2 g) was subjected to HPLC [MeCN–H2O (7:93, v/v)] to afford nine fractions [Fr. 1-3-1, Fr. 1-3-2, Fr.
1-3-3 [= 3-(ꢀ-D-glucopyranosyloxy)-4-methoxybenzaldehyde (8, 20 mg, 0.00093%)], Fr. 1-3-4, Fr. 1-3-5,
Fr. 1-3-6, Fr. 1-3-7 (23 mg), Fr. 1-3-8, Fr. 1-3-9 [= 2-phenylethyl-ꢀ-D-glucopyranoside (9, 7.0 mg,
0.00032%)]. Fraction 1-3-7 (23 mg) was further purified by HPLC [MeOH–H2O (28:72, v/v)] to give
hydracyanoside F (3, 5.0 mg, 0.00023%). Fraction 1-4 (1.2 g) was subjected to HPLC [MeOH–H2O
(32:68, v/v)] to afford four fractions [Fr. 1-4-1, Fr. 1-4-2 (100 mg), Fr. 1-4-3, Fr. 1-4-4]. Fraction 1-4-2
(100 mg) was further purified by HPLC [MeCN–H2O (10:90, v/v)] to give vogeloside (15, 50 mg,
0.0023%), epi-vogeloside (16, 8.3 mg, 0.00038%). Fraction 3 (60 g) was subjected to reversed-phase
silica gel column chromatography [1.2 kg, MeOH–H2O (15:85 ꢀ 25:75 ꢀ 45:55 ꢀ 65:35 ꢀ 85:15, v/v)
ꢀ MeOH ꢀ CHCl3] to afford ten fractions [Fr. 3-1, Fr. 3-2, Fr. 3-3, Fr. 3-4 (4.9 g), Fr. 3-5 (1.5 g), Fr. 3-
6, Fr. 3-7 (1.3 g), Fr. 3-8 (1.8 g), Fr. 3-9, Fr. 3-10 (580 mg)]. Fraction 3-4 (4.9 g) was subjected to HPLC
[MeOH–H2O (15:85, v/v)] to afford hydracyanoside A (4, 1.92 g, 0.09%), hydracyanoside E (2, 4.3 mg,
0.00020%), (2R)-taxiphyllin (5, 6.0 mg, 0.00028%), tachioside (6, 13 mg, 0.00061%), isotachioside (7,
16 mg, 0.00072%), salidroside (10, 3.1 mg, 0.00014%), adenosine (18, 12 mg, 0.00055%), (–)-methyl
shikimate (19, 5.0 mg, 0.00023%). Fraction 3-5 (1.5 g) was subjected to HPLC [MeCN–H2O (10:90,
v/v)] to afford icariside F2 (11, 4.8 mg, 0.00022%). Fraction 3-7 (1.3 g) was subjected to HPLC [MeOH–
H2O (37:63, v/v)] to afford 8-epi-loganin (13, 23 mg, 0.0011%), Z-hex-3-en-1-ol ꢀ-D-xylopyranosyl(1-
6)-ꢀ-D-glucopyranoside (20, 11 mg, 0.00051%). Fraction 3-8 (1.8 g) was subjected to HPLC [MeOH–
H2O (55:45, v/v)] to afford loganin (12, 33 mg, 0.0015%), secoxyloganin (14, 15 mg, 0.00070%).

914
HETEROCYCLES, Vol. 81, No. 4, 2010
Fraction 3-10 (580 mg) was subjected to HPLC [MeOH–H2O (75:25, v/v)] to afford hydracyanoside D (1,
15 mg, 0.00071%).
23
Hydracyanoside D (1): a white powder, [a]D –111.6° (c 0.07, MeOH). High-resolution positive-ion
FABMS: Calcd for C32H41NO17Na (M+Na)+: 734.2272. Found: 734.2269. UV [MeOH, nm, (logꢀ)]: 282
(3.55), 236 (4.24). IR (KBr): 3420, 2923, 2365, 1701, 1655, 1078 cm-1. 1H-NMR (600 MHz, CD3OD) ꢁ:
3.54 (1H, dd, J = 9.6, 10.3 Hz, 6''ꢀ-H), 4.16 (1H, dd, J = 4.4, 10.3 Hz, 6''ꢁ-H), 3.70 (3H, s, COOCH3),
3.87 (3H, s, OCH3), 4.40 (1H, d, J = 8.0 Hz, 1''-H), 4.67 (1H, d, J = 7.6 Hz, 1''''-H), 4.69 (1H, dd, J = 5.5,
7.0 Hz, 7'''-H), 5.24 (1H, br d, J = 11.0 Hz, 10'''a-H), 5.30 (1H, br d, J = 17.8 Hz, 10'''b-H), 5.54 (1H, d, J
= 6.2 Hz, 1'''-H), 5.60 (1H, s, 2-H), 5.73 (1H, ddd, J = 8.2, 11.0, 17.8 Hz, 8'''a-H), 6.95 (1H, dd, J = 2.1,
8.3 Hz, 6'-H), 6.96 (1H, d, J = 8.3 Hz, 5'-H), 7.00 (1H, d, J = 2.1 Hz, 2'-H), 7.45 (1H, s, 3'''-H). 13C-NMR
(150 MHz, CD3OD) ꢁC: given in Table 1. Positive-ion FABMS: m/z 734 (M+Na)+.
24
Hydracyanoside E (2): a white powder, [a]D –29.4° (c 0.02, MeOH). High-resolution positive-ion
FABMS: Calcd for C15H19NO8Na (M+Na)+: 364.1009. Found: 364.1012. UV [MeOH, nm, (logꢀ)]: 289
(3.55), 224 (3.84). IR (KBr): 3570, 2926, 2257, 1074 cm-1. 1H-NMR (600 MHz, CD3OD) ꢁ: 3.81 (3H, s),
3.70 (1H, dd, J = 5.2, 11.7 Hz, 6''a-H), 3.88 (1H, dd, J = 2.0, 11.7 Hz, 6''b-H), 3.65 (1H, s, 2-H2), 4.72
(1H, d, J = 7.6 Hz, 1''-H), 6.54 (1H, s, 3'-H), 7.13 (1H, s, 6'-H). 13C-NMR (150 MHz, CD3OD) ꢁC: given
in Table 2. Positive-ion FABMS: m/z 364 (M+Na)+.
25
Hydracyanoside F (3): a white powder, [a]D –106.2° (c 0.02, MeOH). High-resolution positive-ion
FABMS: Calcd for C17H21NO9Na (M+Na)+: 406.1114. Found: 406.1119. UV [MeOH, nm, (logꢀ)]: 242
1
(3.73). IR (KBr): 3420, 2924, 2361, 1719, 1655, 1074 cm-1. H-NMR (600 MHz, CD3OD) ꢁ: 2.01 (1H,
ddd, J = 5.5, 13.7, 14.5 Hz,, 6ꢀ-H), 2.11 (1H, ddd, J = 2.0, 4.8, 14.5 Hz,, 6ꢁ-H), 4.75 (1H, d, J = 7.6 Hz,
1'-H), 5.31 (1H, dd, J = 2.1, 10.3 Hz, 10a-H), 5.36 (1H, dd, J = 2.1, 17.3 Hz, 10b-H), 5.54 (1H, ddd, J =
9.7, 10.3, 17.3 Hz, 8-H), 5.59 (1H, dd, J = 2.0, 5.5 Hz, 7-H), 5.60 (1H, d, J = 5.5 Hz, 1-H), 7.70 (1H, br s,
3-H). 13C-NMR (150 MHz, CD3OD) ꢁC: given in Table 3. Positive-ion FABMS: m/z 406 (M+Na)+.
Acid Hydrolysis of 1–3. A solution of 1, 2, and 3 (each 1.0 mg) in 1.0 M aqueous HCl (2.0 mL) was
heated under reflux for 3 h. After cooling, the reaction mixture was poured into ice-water and neutralized
with Amberlite IRA-400 (OH– form), and the resin was removed by filtration. Then, the filtrate was
partitioned with EtOAc. The aqueous layer was subjected to HPLC analysis to identify the D-glucose
under the following conditions: HPLC column, Kaseisorb LC NH2-60-5, 4.6 mm i.d. ꢂ 250 mm (Tokyo
Kasei Co., Ltd., Tokyo, Japan); detection, optical rotation [Shodex OR-2 (Showa Denko Co., Ltd., Tokyo,
Japan)]; mobile phase, MeCN–H2O (85:15, v/v); flow rate 0.8 mL/min; column temperature, room
temperature. Identification of D-glucose present in the aqueous layer was carried out by comparison of its
retention time and optical rotation with that of authentic sample. tR: D-glucose, 13.5 min (positive optical
rotation).
Methanolysis of 1
A solution of hydracyanoside D (1, 5 mg, 0.007 mmol) in MeOH containing 0.1M HCl (2mL) was stirred

HETEROCYCLES, Vol. 81, No. 4, 2010
915
at 70 °C for 2 h. The solution was neutralized with Amberlite IRA-400 (OH– form) and the resin was
removed by filtration. Evaporation of the solvent from the filtrate under reduced pressure gave a residue
which was purified by HPLC [Cosmosil 5C18-MS-II, MeOH–H2O (30:70, v/v)] to afford hydracyanoside
A (4, 0.4 mg) and secoxyloganin dimethylacetal (0.3 mg).
ACKNOWLEDGMENTS
This research was supported by the 21st COE program, Academic Frontier Project, and Grand-in Aid for
Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan.
REFERENCES AND NOTES
1. S. Nakamura, Z. Wang, F. Xu, H. Matsuda, L. Wu, and M. Yoshikawa, Tetrahedron Lett., 2009, 50,
4639.
2. H. Zhang, H. Matsuda, C. Yamashita, S. Nakamura, and M. Yoshikawa, Eur. J. Pharmacol., 2009,
606, 255.
3. A. Kurume, Y. Kamata, M. Yamashita, Q. Wang, H. Matsuda, M. Yoshikawa, I. Kawasaki, and S.
Ohta, Chem. Pharm. Bull., 2008, 56, 1264.
4. H. Matsuda, Q. Wang, K. Matsuhira, S. Nakamura, D. Yuan, and M. Yoshikawa, Phytomedicine,
2008, 15, 177.
5. H. Zhang, H. Matsuda, A. Kumahara, Y. Ito, S. Nakamura, and M. Yoshikawa, Bioorg. Med. Chem.,
Lett., 2007, 17, 4972.
6. Q. Wang, H. Matsuda, K. Matsuhira, S. Nakamura, D. Yuan, and M. Yoshikawa, Biol. Pharm. Bull.,
2007, 30, 388.
7. G. H. N. Towers, A. G. McInnes, and A. C. Neish, Tetrahedron, 1964, 20, 71.
8. D. S. Seigler, G. F. Pauli, R. Fröhlich, E. Wegelius, A. Nahrstedt, K. E. Glander, and J. E. Ebinger,
Phytochemistry, 2005, 66, 1567.
9. X.-N. Zhong, H. Otsuka, T. Ide, E. Hirata, and Y. Takeda, Phytochemistry, 1999, 52, 923.
10. A. E. Pavlov, V. M. Sokolov, and V. I. Zakharov, Russ. J. Gen. Chem., 2001, 71, 1811.
11. K. Kurashima, M. Fujii, Y. Ida, and H. Akita, Chem. Pharm. Bull., 2004, 52, 270.
12. H. Nishimura, G. Nonaka, and I. Nishioka, Chem. Pharm. Bull., 1984, 32, 1735.
13. T. Miyase, A. Ueno, N. Takizawa, H. Kobayashi, and H. Oguchi, Chem. Pharm. Bull., 1988, 36,
2475.
14. K. Mitsunaga, K. Koike, H. Fukuda, K. Ishii, and T. Ohmoto, Chem. Pharm. Bull., 1991, 39, 2737.
15. A. Bianco and P. Passacantilli, Phytochemistry, 1981, 20, 1873.
16. I. Calis and O. Sticher, Phytochemistry, 1984, 23, 2539.
17. H. Kawai, M. Kuroyanagi, and A. Ueno, Chem. Pharm. Bull., 1988, 36, 3664.
18. This compound was identified by comparison of the physical data with commercially obtained
sample.
19. A. J. Jones, D. M. Grant, M. W. Winkley, and R. K. Robins, J. Am. Chem. Soc., 1970, 92, 4079.
20. P. Ciuffreda, S. Casati, and A. Manzocchi, Magn. Reson. Chem., 2007, 45, 781.

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21. J. Huang and F.-E. Chen, Helv. Chim. Acta, 2007, 90, 1366.
22. M. Kishida, M. Fujii, Y. Ida, and H. Akita, Heterocycles, 2005, 65, 2127.
23. S. Sugimoto, S. Nakamura, S. Yamamoto, C. Yamashita, Y. Oda, H. Matsuda, and M. Yoshikawa,
Chem. Pharm. Bull., 2009, 57, 257.
24. S. Nakamura, M. Hongo, S. Sugimoto, H. Matsuda, and M. Yoshikawa, Phytochemistry, 2008, 69,
1565.
1
13
25. The H- and C-NMR spectra of 1–3 were assigned with the aid of distortionless enhancement by
polarization transfer (DEPT), double quantum filter correlation spectroscopy (DQF COSY),
heteronuclear multiple quantum coherence spectroscopy (HMQC), and heteronuclear multiple bond
connectivity spectroscopy (HMBC) experiments.