Structure elucidation and NMR spectral assignments of four neolignan glycosides with enantiometric aglycones from Osmanthus ilicifolius

Article abstract of DOI:10.1002/mrc.2292

Four new 8-O-4′ type neolignan glycosides with enantiometric aglycones, (7S,8R)-erythro-guaiacylglycerol-β-O-4′-sinapyl ether 9-O-β-D-glucopyranoside (1), (7R,8S)-erythro-guaiacylglycerol-β-O- 4′-sinapyl ether 9-O-β-D-glucopyranoside (2), (7S,8R)-erythro-

Full text of DOI:10.1002/mrc.2292

Spectral Assignments and Reference Data
Received: 11 April 2008
Revised: 27 June 2008
Accepted: 28 June 2008
Published online in Wiley Interscience: 21 August 2008
(www.interscience.com) DOI 10.1002/mrc.2292
Structure elucidation and NMR spectral
assignments of four neolignan glycosides
with enantiometric aglycones from Osmanthus
ilicifolius
Koichi Machida, Shigeaki Sakamoto and Masao Kikuchi∗
Four new 8-O-4ꢀ type neolignan glycosides with enantiometric aglycones, (7S,8R)-erythro-guaiacylglycerol-β-O-4ꢀ-sinapyl
ether 9-O-β-D-glucopyranoside (1), (7R,8S)-erythro-guaiacylglycerol-β-O-4ꢀ-sinapyl ether 9-O-β-D-glucopyranoside (2), (7S,8R)-
erythro- syringylglycerol-β-O-4ꢀ-sinapyl ether 9-O-β-D-glucopyranoside (3) and (7R,8S)-erythro- syringylglycerol-β-O-4ꢀ-sinapyl
ether 9-O-β-D-glucopyranoside (4), were isolated from the leaves of Osmanthus ilicifolius. Their structures were established on
the basis of NMR, circular dichroism (CD), MS and chemical data. The NMR assignments for the compounds were carried out
using 1H, 13C, COSY, HMQC, HMBC and NOESY NMR experiments. Copyright ꢀ 2008 John Wiley & Sons, Ltd.
c
Keywords: NMR; 1H; 13C; Osmanthus ilicifolius; Oleaceae; 8-O-4ꢁ-neolignan glycoside
Introduction
features including the molecular formula indicated that 1 was an
8-O-4ꢁ-type neolignan glycoside formed by two phenylpropanoid
units. Detailed analyses of the 1H (Table 1) and 13C (Table 2) NMR
signals of 1 were undertaken with the aid of HMQC and DEPT
experiments and the constitutional structure of 1 was established
by the HMBC experiment (Fig. 2). The nuclear Overhauser effect
(NOE) correlations (H-7/H-8, H-2, 6/H-9A, H-2,6/H-8) of 1 indicated
that 1 possessed an erythro relative configuration. Additionally,
enzymatic hydrolysis of 1 afforded an aglycone (1a). An erythro
configuration of 1 was also confirmed by the J7,8 (3.4 Hz) in the
1H NMR spectrum (CDCl3) of 1a.[7–9] The absolute configuration
at C-7 and C-8 of 1 was assigned to be 7S,8R on the basis of the
negative circular dichroism (CD) Cotton effect (236 nm, ꢀε −4.1)
of 1a.[8–11] Consequently, the structure of 1 was determined to
be (7S,8R)-erythro-guaiacylglycerol-β-O-4ꢁ-sinapyl ether 9-O-β-D-
glucopyranoside.
Oleaceae is a family of medium size with 25 genera and
about 600 species, and this family is a rich source of iridoid,
secoiridoid, phenylpropanoid and lignan glycosides.[1] As part of
our continued studies on the constituents of oleaceous plants,
we previously reported the isolation and identification of two
bis-iridoid glycosides,[2] four secoiridoid di-glycosides[3] along
with three known secoiridoid glycosides[4] and ten known lignan
glycosides[4,5] from the leaves of Osmanthus ilicifolius. The leaves
of this plant has been used in Japan as a herbal drug for vitiligo
vulgaris.[6] In the course of further studies on the constituents
of this plant, four new 8-O-4ꢁ type neolignan glycosides with
enantiometric aglycones (1–4) (Fig. 1) have been isolated. It is the
first report to isolate 8-O-4ꢁ type neolignans from Osmanthus
genus. This article deals with the structural elucidation and
identification of these compounds.
Compound 2 was obtained as an amorphous powder,
[α]D −36.1◦ (MeOH). The molecular formula of 2, C27H36O13
,
was confirmed by HR-FAB-MS and was coincident with that of 1.
Its 1H (Table 1) and 13C NMR (Table 2) spectra were very similar to
those of 1, suggesting that the overall structure of 2 was the same
Results and Discussion
Compound 1 was obtained as an amorphous powder, [α]D −3.5◦
(MeOH). The molecular formula of 1, C27H36O13, was confirmed by
high resolution-fast atom bombardment-mass spectrometry (HR-
FAB-MS). In the 1H NMR spectrum of 1, three methoxyl groups [δH
3.81(9H,s)],ananomericprotonsignal[δH 4.21(1H,d,J = 7.8 Hz,H-
1ꢁꢁ)], a 1,3,4-trisubstituted benzene ring [δH 6.73 (1H, d, J = 8.1 Hz,
H-5), 6.84 (1H, dd, J = 8.1, 2.0 Hz, H-6), 7.03 (1H, d, J = 2.0 Hz,
H-2)] and a symmetrically 1,3,4,5-tetrasubstituted benzene ring
[δH 6.70 (2H, s, H-2ꢁ,6ꢁ)], and two olefinic proton signals [δH 6.30
(1H, dt, J = 15.9, 5.6 Hz, H-8ꢁ), 6.53 (1H, br d, J = 15.9 Hz, H-7ꢁ)]
1
as that of 1. The HMBC and H–1H COSY correlations of 2 also
corroborated the above deduction (Fig. 2). Enzymatic hydrolysis of
2 afforded an aglycone (2a), and the 1H NMR spectrum of2a was in
agreementwiththatof1a.Theseindicatedthat2possessedanery-
thro relative configuration, and the aglycone parts of 1 and 2 were
deduced to be enantiometric structures. Furthermore, the positive
CD Cotton effect (236 nm, ꢀε +4.6) of 2a indicated the absolute
∗
Correspondence to: Masao Kikuchi, Tohoku Pharmaceutical University, 4-4-1
of a trans double-bond were observed. Furthermore, the H–1H
1
Komatsushima, Aoba-ku, Sendai, Miyagi 981-8558, Japan.
E-mail: mkikuchi@tohoku-pharm.ac.jp
COSY spectrum of 1 revealed the presence of a 1,2,3-propanetriol
moiety (C–7–8–9) and a 3-hydroxy-1-trans-propenyl moiety (C-
7ꢁ –8ꢁ –9ꢁ). Acid hydrolysis of 1 yielded D-glucose. These spectral
Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai,
Miyagi 981-8558, Japan
c
Magn. Reson. Chem. 2008, 46, 990–994
Copyright ꢀ 2008 John Wiley & Sons, Ltd.

Spectral Assignments and Reference Data
Figure 1. Structures of compounds 1–4.
Table 1. 1H NMR data for compounds 1–4 (400 MHz, CD3OD)
Position
1
2
3
4
2
5
6
7
8
9
7.03 d (2.0)
6.73 d (8.1)
6.84 dd (8.1,2.0)
4.92 d (5.4)
4.45 m
6.98 d (1.7)
6.72 d (8.1)
6.77 dd (8.1,1.7)
4.88 d (4.4)
4.47 m
6.73 s
–
6.68 s
–
6.73 s
6.68 s
4.92 d (4.9)
4.45 dt (4.9,4.8)
3.63 dd (10.6,4.8)
4.27 dd (10.6,4.8)
3.81 s
4.89 d (4.4)
4.48 m
3.65 dd (10.7,4.4)
4.24 dd (10.7,4.6)
3.81 s
3.94 dd (11.5,5.9)
4.00 dd (11.5,3.9)
3.81 s
3.94 dd (11.5,5.6)
4.02 dd (11.5,3.7)
3.81 s
3-OCH3
5-OCH3
–
–
3.81 s
3.81 s
2ꢁ, 6ꢁ
6.70 s
6.74 s
6.70 s
6.73 s
7ꢁ
6.53 br d (15.9)
6.30 dt (15.9,5.6)
4.21 dd (5.6,1.5)
3.81 s
6.55 br d (15.9)
6.32 dt (15.9,5.6)
4.22 dd (5.6,1.5)
3.85 s
6.53 br d (15.8)
6.31 dt (15.8,5.9)
4.21 dd (5.9,1.5)
3.81 s
6.55 br d (15.9)
6.32 dt (15.9,5.6)
4.22 dd (5.6,1.2)
3.84 s
8ꢁ
9ꢁ
3ꢁꢁꢁ,5ꢁ-OCH3
1
4.21 d (7.8)
3.22 dd (8.8, 7.8)
3.38 m
4.30 d (7.8)
3.17 dd (9.0,7.8)
3.32 m
4.21 d (7.7)
3.22 (8.8, 7.7)
3.32 m
4.31 d (7.8)
3.18 dd (8.9, 7.8)
3.32 m
2ꢁꢁ
3ꢁꢁ
4ꢁꢁ
5ꢁꢁ
6ꢁꢁ
3.38 m
3.32 m
3.32 m
3.32 m
3.18 m
3.22 m
3.19 m
3.22 m
3.66 dd (12.0,5.4)
3.81 dd (12.0,2.2)
3.64 dd (12.0,5.4)
3.81 dd (12.0,2.4)
3.66 dd (11.7,5.9)
3.81 dd (11.7,2.2)
3.64 dd (12.0,5.4)
3.84 dd (12.0,2.4)
configuration of 2 to be 7R,8S.[8–11] Consequently, the structure
of 2 was determined to be (7R,8S)-erythro-guaiacylglycerol-β-O-
4ꢁ-sinapyl ether 9-O-β-D-glucopyranoside.
(239 nm, ꢀε −6.4)of3a.[8–11] Consequently, thestructureof 3was
determined to be (7S,8R)-erythro-syringylglycerol- β-O-4ꢁ-sinapyl
ether 9-O-β-D-glucopyranoside.
Compound 3 was obtained as an amorphous powder,
Compound 4 was obtained as an amorphous powder,
[α]D −12.3◦ (MeOH). The molecular formula of 3, C28H38O14
,
[α]D −20.6◦ (MeOH). The molecular formula of 4, C28H38O14
,
was confirmed by HR-FAB-MS. The 1H NMR spectrum of 3 was
similar to that of 1, except for the presence of an additional
methoxyl group [δH 3.81 (12H, s)] and two symmetrically 1,3,4,5-
tetrasubstituted benzene rings [δH 6.70 (2H, s, H-2ꢁ,6ꢁ), 6.73 (2H,
H-2,6)]. These indicated that the additional methoxyl group of
3 is attached to C-5. This finding was supported by the HMBC
and 1H–1H COSY experiments (Fig. 2). Enzymatic hydrolysis of
3 afforded an aglycone (3a). An erythro configuration of 3 was
confirmed by the J7,8 (3.9 Hz) in the 1H NMR spectrum (CDCl3)
of 3a.[7–9] The absolute configuration at C-7 and C-8 of 3 was
assigned to be 7S,8R on the basis of the negative CD Cotton effect
was confirmed by HR-FAB-MS and was coincident with that of 3.
1
Its H (Table 1) and 13C NMR (Table 2) spectra were very similar
to those of 3, suggesting that the overall structure of 4 was the
same as that of 3. The HMBC and 1H–1H COSY correlations of 4
also corroborated the above deduction (Fig. 2). Enzymatic hydrol-
ysis of 4 afforded an aglycone (4a), and the 1H-NMR spectrum
of 4a was in agreement with that of 3a, except for the signs
of the CD Cotton effect (239 nm, ꢀε +7.0).[8–11] Therefore, the
aglycone parts of 3 and 4 were deduced to be enantiometric
structures. Consequently, the structure of 4 was determined to
c
Magn. Reson. Chem. 2008, 46, 990–994
Copyright ꢀ 2008 John Wiley & Sons, Ltd.
www.interscience.wiley.com/journal/mrc

Spectral Assignments and Reference Data
Figure 2. Main HMBC correlations. Heavy lines indicated partial structures inferred from 1H–1H COSY.
To our knowledge, this is the first report of the isolation and
structural elucidation of 8-O-4ꢁ type neolignan glycoside from the
Osmanthus genus, and it is rare to isolate 8-O-4ꢁ type neolignan
glycosides (1 and 2, 3 and 4) with enantiometric aglycone from
the same plant.
Table 2. 13C NMR data for compounds 1–4 (100 MHz, CD3OD)
Position
1
2
3
4
1
133.5
112.1
148.6
147.0
115.6
121.4
74.2
133.3
111.5
148.7
146.9
115.7
120.7
73.9
132.7
106.0
148.9
135.9
148.9
106.0
74.4
132.5
105.3
149.0
135.8
149.0
105.3
74.2
2
3
4
Experimental
5
General experimental procedures
6
Optical rotations were measured with a JASCO DIP-360 digital
polarimeter.ultraviolet(UV)spectrawererecordedwithaBeckman
DU-64 spectrometer. FAB-MS were recorded on a JEOL JMS-DX
303 mass spectrometer. The CD spectra were obtained with a
JASCO J-720 spectropolarimeter. Column chromatography was
carried out on Kieselgel 60 (Merck; 230–400 mesh) and Sephadex
LH-20 (Pharmacia Fine Chemicals). HPLC was carried out on a
Tosoh HPLC system [pump, CCPS; detector, UV-8020; column,
TSK gel ODS 120T (7.8 mm i.d. × 30 cm, Tosoh), TSK gel 80TM
(6.0 mm i.d.×15 cm, Tosoh) and Cosmosil 5SL (10 mm i.d.×25 cm,
Nacalai).
7
8
85.7
86.2
85.8
86.1
9
69.3
69.6
69.5
69.7
1ꢁ
134.7
104.8
154.4
136.7
154.4
104.8
131.5
129.8
63.7
134.8
105.0
154.5
136.4
154.5
105.0
131.4
129.9
63.6
134.7
104.8
154.4
136.9
154.4
104.8
131.4
129.8
63.7
134.8
105.0
154.5
136.5
154.5
105.0
131.4
129.9
63.6
2ꢁ
3ꢁ
4ꢁ
5ꢁ
6ꢁ
7ꢁ
8ꢁ
9ꢁ
NMR spectroscopy
3-OCH3
56.4
56.4
56.7
56.8
5-OCH3
–
–
56.7
56.8
The 1H and 13C NMR spectra were recorded with JEOL JNM-LA
400 spectrometer. Compounds were dissolved in CD3OD (1–4) or
CDCl3 (1a–4a) containing TMS as an internal standard. Chemical
shifts are given in a δ (ppm) scale and referenced to TMS at
0.00 ppm for proton and carbon. Coupling constants (J) are
in Hz. The pulse conditions were as follows. For 1H NMR,
observation frequency 399.65 MHz, acquisition time (AQ) 4.099 s,
relaxation delay (RD) 2.9 s, 90◦ pulse width 7.0 µs, spectral width
(SW) 7993.6 Hz, Fourier transform (FT) size 32 768; for 13C NMR,
observation frequency 100.40 MHz, AQ 2.418 s, RD 2.000 s, 90◦
pulse width 5.6 µs, SW 27 100.3 Hz, FT size 65 536; for 1H–1H COSY
and NOESY spectra, AQ 0.112 s, RD 1.2 s, SW 4574.6 Hz, 90◦ pulse
width 14.0 µs, number of points (NP) 512, number of increments
(NI) 256, the mixing time of NOESY 0.5 s; for HMQC and HMBC
spectra, AQ 0.120 s, RD 1.5 s, SW 4249.9 Hz (1H) and 24 154.6 Hz
3ꢁ-OCH3
56.7
56.7
56.8
56.8
5ꢁꢁꢁ-OCH3
56.7
56.7
56.8
56.8
1ꢁꢁ
2
104.6
75.2
105.0
75.3
104.7
75.2
105.0
75.3
3ꢁꢁ
4ꢁꢁ
5ꢁꢁ
6ꢁꢁ
77.9
77.8
78.0
78.0
71.5
71.6
71.5
71.6
78.0
78.0
78.0
77.8
62.6
62.7
62.6
62.7
be (7R,8S)-erythro-syringylglycerol-β-O-4ꢁ-sinapyl ether 9-O-β-D-
glucopyranoside.
A compound with the same constitution as syringylglycerol-
β-O-4ꢁ-sinapyl ether 9-O-β-D-glucopyranoside was isolated from
Saccharum officinarum L. by Takara et al., but its relative and
absolute configurations were not discussed.[12] The 1H and
13C NMR spectral data of our glycoside having (7R,8S)-erythro
configuration (4) and the glycoside isolated by Takara et al. are
almost identical. Thus, the glycoside isolated by Takara et al. seems
to be the same as 4.
(
13C), NP 512, FT size 512 × 512.
Plant material
The leaves of O. ilicifolius were collected in August, 2005 in Sendai,
Miyagi prefecture, Japan, and identified by one of the authors
(M. Kikuchi). A voucher specimen (2005-8-KM1) is held in the
laboratory of M. Kikuchi.
c
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Copyright ꢀ 2008 John Wiley & Sons, Ltd.
Magn. Reson. Chem. 2008, 46, 990–994

Spectral Assignments and Reference Data
Extraction and isolation
(4.5), 270 (4.2). CD (c = 2.9 × 10−5 M, MeOH) ꢀε: +5.9 (234),
−2.5 (270). FAB-MS m/z: 591 [M + Na]+. HR-FAB-MS m/z: 591.2070
Fresh leaves of O. ilicifolius (2.6 kg) were extracted with MeOH
at rt for 8 months. The MeOH extract was concentrated under
reduced pressure and the residue (466 g) was suspended in water.
This suspension was successively extracted with CHCl3, AcOEt, n-
BuOH and H2O. The n-BuOH-soluble fraction was concentrated
under reduced pressure to produce a residue (167 g). The
extract (74 g) was chromatographed on a silica gel column using
CHCl3 –MeOH–H2O (50 : 10 : 1, 30 : 10 : 1, 10 : 10 : 1) and the eluate
was separated into four fractions (frs. 1–4).
Fraction 2 was chromatographed on a Sephadex LH-20 column
using 50% MeOH and the eluate was separated into 12 fractions
(frs. 2-1-2-12). Part of the fraction 2–6 (1.5 g) was subjected to
preparative HPLC [column, TSK gel ODS 120T; mobile phase,
MeOH–H2O (2 : 3); UV detector, 205 nm; flow rate, 1.5 ml/min;
column temperature, 40 ◦C] to give 11 peaks (peaks 1–11). Peak
1 was subjected to preparative HPLC [column, TSK gel ODS-
120T; mobile phase, MeOH–H2O (4 : 11); UV detector, 205 nm;
flow rate, 1.5 ml/min; column temperature, 40 ◦C] to give seven
peaks (peaks 1-1-1-7). Peak 1–4 was subjected to preparative
HPLC [column, Cosmosil 5SL; mobile phase, CHCl3 –MeOH–H2O
(70 : 10 : 1); UV detector, 230 nm; flow rate, 1.5 ml/min; column
temperature, 40 ◦C] to give seven peaks (peaks 1-4-1-1-4-7). Peak
1-4-3 was subjected to preparative HPLC [column, TSK gel ODS-
80TM; mobile phase, MeOH–H2O (1 : 3); UV detector, 205 nm; flow
rate, 1.0 ml/min;columntemperature, 40 ◦C]togive2(4.0 mg)and
4 (4.2 mg). Peak 1-4-4 was subjected to preparative HPLC [column,
TSK gel ODS-120T; mobile phase, MeOH–H2O (1 : 3); UV detector,
205 nm; flow rate, 1.5 ml/min; column temperature, 40 ◦C] to give
1 (9.5 mg) and 3 (6.0 mg).
1
([M + Na]+, Calcd for C27H36O13Na: 591.2053). H and 13C-NMR
(CD3OD): Tables 1 and 2.
Enzymatic hydrolysis of 2
An aqueous solution (3.0 ml) containing 2 (2.5 mg), cellulose
(20 mg) was incubated at 40 ◦C for 3 d. The reaction mixture
was extracted with CHCl3, and the CHCl3 layer was evaporated
underreducedpressure.TheresiduewaspurifiedbyHPLC[column,
ODS-80TM; mobile phase, MeOH–H2O (1 : 2); UV detector, 205 nm;
flow rate, 1.0 ml/min; column temperature, 40 ◦C] to give (7R,8S)-
erythro-guaiacylglycerol-β-O-4ꢁ-sinapyl ether (2a, 1.7 mg).
(7R,8S)-erythro-Guaiacylglycerol-β-O-4ꢁ-sinapyl ether (2a) An
amorphous powder, [α]D −8.4◦ (c = 0.10, MeOH). UV λmax
25
(MeOH) nm (log ε) : 204 (4.4), 218 sh (4.3), 271 (4.0). CD
(c = 4.2 × 10−5 M, MeOH) ꢀε: +4.6 (236). FAB-MS m/z: 429
[M + Na]+. HR-FAB-MS m/z: 429.1523 ([M + Na]+, Calcd for
C21H26O8Na: 429.1525). 1H-NMR (CDCl3) δ: 3.50 (1H, dd, J = 11.5,
2.9 Hz, H-9A), 3.90 (9H, s, 3, 3ꢁ, 5ꢁ-OCH3), 3.91 (1H, m, H-9B), 4.14 (1H,
m, H-8), 4.35 (2H, dd, J = 5.9, 1.5 Hz, H2-9ꢁ), 5.01 (1H, d, J = 3.4 Hz,
H-7), 6.33 (1H, dt, J = 15.6, 5.9 Hz, H-8ꢁ), 6.58 (1H, br d, J = 15.6 Hz,
H-7ꢁ), 6.68 (2H, s, H-2ꢁ, 6ꢁ), 6.75 (1H, dd, J = 8.1, 1.5 Hz, H-6), 6.86
(1H, d, J = 8.1 Hz, H-5), 6.96 (1H, d, J = 1.5 Hz, H-2).
(7S,8R)-erythro-Syringylglycerol-β-O-4ꢁ-sinapyl ether 9-O-β-D-
25
glucopyranoside (3) An amorphous powder, [α]D
−12.3◦
(c = 0.19, MeOH). UV λmax (MeOH) nm (log ε) : 203 (4.8), 220
sh (4.5), 269 (4.1). CD (c = 2.9 × 10−5 M, MeOH) ꢀε: −2.3 (233),
−2.2 (242), +1.4 (270). FAB-MS m/z: 621 [M + Na]+. HR-FAB-MS
m/z: 621.2144 ([M + Na]+, Calcd for C28H38O14Na: 621.2160). 1H
and 13C-NMR (CD3OD): Tables 1 and 2.
(7S,8R)-erythro-Guaiacylglycerol-β-O-4ꢁ-sinapyl ether 9-O-β-D-
glucopyranoside (1) An amorphous powder, [α]D −3.5◦ (c =
25
Enzymatic hydrolysis of 3
0.29, MeOH). UV λmax (MeOH) nm (log ε) : 203 (4.6), 220 (4.5), 271
(4.2). CD (c = 3.0×10−5 M, MeOH)ꢀε: −4.0 (234), +1.5 (270). FAB-
MSm/z:591[M+Na]+. HR-FAB-MSm/z:591.2032([M+Na]+, Calcd
An aqueous solution (5.0 ml) containing 3 (2.8 mg), cellulose
(20 mg) was incubated at 40 ◦C for 4 d. The reaction mixture
was extracted with CHCl3, and the CHCl3 layer was evaporated
underreducedpressure.TheresiduewaspurifiedbyHPLC[column,
ODS-80TM; mobile phase, MeOH–H2O (1 : 2); UV detector, 205 nm;
flow rate, 1.0 ml/min; column temperature, 40 ◦C] to give (7S,8R)-
erythro-syringylglycerol-β-O-4ꢁ-sinapyl ether (3a, 1.5 mg).
for C27H36O13Na: 591.2053). H and 13C-NMR (CD3OD): Tables 1
1
and 2.
Enzymatic hydrolysis of 1
(7S,8R)-erythro-Syringylglycerol-β-O-4ꢁ-sinapyl ether (3a) An
An aqueous solution (5.0 ml) containing 1 (4.0 mg), cellulose
(20 mg) was incubated at 40 ◦C for 4 d. The reaction mixture
was extracted with CHCl3, and the CHCl3 layer was evaporated
underreducedpressure.TheresiduewaspurifiedbyHPLC[column,
ODS-80TM; mobile phase, MeOH–H2O (1 : 2); UV detector, 205 nm;
flow rate, 1.0 ml/min; column temperature, 40 ◦C] to give (7S,8R)-
erythro-guaiacylglycerol-β-O-4ꢁ-sinapyl ether (1a, 2.0 mg).
amorphous powder, [α]D +12.2◦ (c = 0.12, MeOH). UV λmax
25
(MeOH) nm (log ε) : 209 (5.0), 268 (4.2). CD (c = 2.4 × 10−5 M,
MeOH) ꢀε: −6.4 (239). FAB-MS m/z: 459 [M + Na]+. HR-FAB-MS
1
m/z: 459.1638 ([M + Na]+, Calcd for C22H28O9Na: 459.1631). H-
NMR (CDCl3) δ: 3.48 (1H, m, H-9A), 3.88 (1H, m, H-9B), 3.89, 3.90
(each 6H, s, 3, 5, 3ꢁ, 5ꢁ-OCH3), 4.13 (1H, m, H-8), 4.36 (2H, dd, J = 5.9,
1.5 Hz, H2-9ꢁ), 4.99 (1H, d, J = 3.9 Hz, H-7), 6.34 (1H, dt, J = 15.6,
5.9 Hz, H-8ꢁ), 6.59 (1H, br d, J = 15.6 Hz, H-7ꢁ), 6.58 (2H, s, H-2, 6),
6.69 (2H, s, H-2ꢁ, 6ꢁ).
(7S,8R)-erythro-Guaiacylglycerol-β-O-4ꢁ-sinapyl ether (1a) An
amorphous powder, [α]D +10.2◦ (c = 0.10, MeOH). UV λmax
25
(MeOH) nm (log ε) : 204 (4.6), 218 sh (4.4), 271 (4.1). CD
(c = 3.6 × 10−5 M, MeOH) ꢀε: −4.1 (236). FAB-MS m/z: 429
[M + Na]+. HR-FAB-MS m/z: 429.1527 ([M + Na]+, Calcd for
C21H26O8Na: 429.1525). 1H-NMR (CDCl3) δ: 3.50 (1H, dd, J = 11.5,
2.9 Hz, H-9A), 3.90 (9H, s, 3, 3ꢁ, 5ꢁ-OCH3), 3.91 (1H, m, H-9B), 4.14 (1H,
m, H-8), 4.35 (2H, dd, J = 5.9, 1.5 Hz, H2-9ꢁ), 5.01 (1H, d, J = 3.4 Hz,
H-7), 6.33 (1H, dt, J = 15.6, 5.9 Hz, H-8ꢁ), 6.58 (1H, br d, J = 15.6 Hz,
H-7ꢁ), 6.68 (2H, s, H-2ꢁ, 6ꢁ), 6.75 (1H, dd, J = 8.1, 1.5 Hz, H-6), 6.86
(1H, d, J = 8.1 Hz, H-5), 6.96 (1H, d, J = 1.5 Hz, H-2).
(7R,8S)-erythro-Syringylglycerol-β-O-4ꢁ-sinapyl ether 9-O-β-D-
25
glucopyranoside (4) An amorphous powder, [α]D
−20.6◦
(c = 0.15, MeOH). UV λmax (MeOH) nm (log ε) : 203 (4.7), 220
sh (4.5), 269 (4.1). CD (c = 3.0 × 10−5 M, MeOH) ꢀε: +2.6 (233),
+2.9 (242), −2.0 (270). FAB-MS m/z: 621 [M + Na]+. HR-FAB-MS
m/z: 621.2170 ([M + Na]+, Calcd for C28H38O14Na: 621.2160). 1H
and 13C-NMR (CD3OD): Tables 1 and 2.
Enzymatic hydrolysis of 4
(7R,8S)-erythro-Guaiacylglycerol-β-O-4ꢁ-sinapyl ether 9-O-β-D-
glucopyranoside (2) An amorphous powder, [α]D
(c = 0.17, MeOH). UV λmax (MeOH) nm (log ε) : 202 (4.6), 220
−36.1◦
An aqueous solution (3.0 ml) containing 4 (2.0 mg), cellulose
25
(20 mg) was incubated at 40 ◦C for 3 d. The reaction mixture
c
Magn. Reson. Chem. 2008, 46, 990–994
Copyright ꢀ 2008 John Wiley & Sons, Ltd.
www.interscience.wiley.com/journal/mrc

Spectral Assignments and Reference Data
was extracted with CHCl3, and the CHCl3 layer was evapo-
rated under reduced pressure. The residue was purified by HPLC
[column, ODS-80TM; mobile phase, MeOH–H2O (1 : 2); UV detec-
tor, 205 nm; flow rate, 1.0 ml/min; column temperature, 40 ◦C]
to give (7R,8S)-erythro-syringylglycerol-β-O-4ꢁ-sinapyl ether (3a,
0.8 mg).
rotation with that of authentic sample; tR (min) 39.0 (D-glucose,
positive optical rotation).
Acknowledgements
The authors are grateful to Mrs S. Sato and T. Matsuki of
Tohoku Pharmaceutical University for conducting the NMR and
MS measurements.
(7R,8S)-erythro-Syringylglycerol-β-O-4ꢁ-sinapyl ether (4a) An
amorphous powder, [α]D −12.2◦ (c = 0.07, MeOH). UV λmax
25
(MeOH) nm (log ε) : 206 (4.8), 218 sh (4.6), 268 (4.2). CD
(c = 2.6 × 10−5 M, MeOH) ꢀε: +7.0 (239). FAB-MS m/z: 459
[M + Na]+. HR-FAB-MS m/z: 459.1624 ([M + Na]+, Calcd for
C22H28O9Na: 459.1631). 1H-NMR (CDCl3) δ: 3.48 (1H, m, H-9A),
3.88 (1H, m, H-9B), 3.89, 3.90 (each 6H, s, 3, 5, 3ꢁ, 5ꢁ-OCH3), 4.13 (1H,
m, H-8), 4.36 (2H, dd, J = 5.9, 1.5 Hz, H2-9ꢁ), 4.99 (1H, d, J = 3.9 Hz,
H-7), 6.34 (1H, dt, J = 15.6, 5.9 Hz, H-8ꢁ), 6.59 (1H, br d, J = 15.6 Hz,
H-7ꢁ), 6.58 (2H, s, H-2, 6), 6.69 (2H, s, H-2ꢁ, 6ꢁ).
References
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Acid hydrolysis of 1–4
Each of compounds (ca 1.0 mg) was refluxed with 1 M HCl (1 ml)
for 5 h. The reaction mixture was neutralized with Ag2CO3 and
filtered. The solution was concentrated in vacuo and dried to give
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i.d. × 30 cm, Tosoh); column temperature, 45 ◦C; mobile phase,
CH3CN–H2O (4 : 1); flow rate, 1.0 ml/min; chiral detection (JASCO
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c
www.interscience.wiley.com/journal/mrc
Copyright ꢀ 2008 John Wiley & Sons, Ltd.
Magn. Reson. Chem. 2008, 46, 990–994