Megastigmanes and their glucosides from the whole plant of Sedum sarmentosum

Article abstract of DOI:10.1021/np068059s

Two new megastigmanes, sarmentoic acid (1) and sarmentol A (2), and six new megastigmane glucosides, sedumosides A₁ (3), A₂ (4), A₃ (5), B (6), C (7), and D (8), were isolated from me whole plant of Sedum sarmentosum toget

Full text of DOI:10.1021/np068059s

J. Nat. Prod. 2007, 70, 575-583
575
Megastigmanes and Their Glucosides from the Whole Plant of Sedum sarmentosum1
Masayuki Yoshikawa,*,† Toshio Morikawa,†,‡ Yi Zhang,† Seikou Nakamura,† Osamu Muraoka,‡,§ and Hisashi Matsuda†
Kyoto Pharmaceutical UniVersity, Misasagi, Yamashina-ku, Kyoto 607-8412, Japan, and Pharmaceutical Research and Technology Institute
and School of Pharmacy, Kinki UniVersity, 3-4-1 Kowakae, Higashi-osaka, Osaka 577-8502, Japan
ReceiVed October 24, 2006
Two new megastigmanes, sarmentoic acid (1) and sarmentol A (2), and six new megastigmane glucosides, sedumosides
A1 (3), A2 (4), A3 (5), B (6), C (7), and D (8), were isolated from the whole plant of Sedum sarmentosum together with
eight known megastigmanes (9-16). The absolute stereostructures of 1-8 were elucidated on the basis of chemical
and physicochemical evidence, including the application of the modified Mosher’s method.
The plant Sedum sarmentosum (Crassulaceae) is a perennial herb
widely distributed on the mountain slopes in China (e.g., Anhui,
Hebei, Jiangxi, and Jiangsu Provinces). The whole plant of S.
sarmentosum has been used for the treatment of chronic viral
hepatitis in Chinese and Korean traditional medicines.2,3 In previous
studies, several flavonoid,4-7 sterol,5,8 triterpene,5,9 and cyanogenic
constituents10,11 were isolated from this herbal medicine. During
the course of our studies on bioactive constituents from Chinese
natural medicines,1,12-24 two new megastigmanes, sarmentoic acid
(1) and sarmentol A (2), and six new megastigmane glucosides,
sedumosides A1 (3), A2 (4), A3 (5), B (6), C (7), and D (8), were
isolated from the whole plant of S. sarmentosum together with eight
known megastigmanes (9-16). This paper deals with the isolation
and structure elucidation, including the absolute configuration, of
1-8.
and in the HMBC experiment, long-range correlations were
observed between the following: H2-2 and C-1; H-6 and C-1; H-9
and C-7, 8, 10; H3-11 and C-1, 2, 6, 12; H3-12 and C-1, 2, 6, 11;
H3-13 and C-4-6. The relative stereostructure of 1 except for the
9-position was characterized by the NOESY experiment, which
showed NOE correlations between HR-2 and H-3, H-6, H3-12; H-3
and HR-4; HR-4 and H-6, H3-13; H-6 and H3-12; and H2-7 and
H3-11, as shown in Figure S1. Finally, the absolute configuration
of 1 was characterized by the application of the modified Mosher’s
method.31 Namely, methyl ester 1a, which was derived from 1 upon
reaction with trimethylsilyldiazomethane (TMSCHN2), gave the
3-(R)-MTPA ester (1b), 9-(R)-MTPA ester (1d), and 3,9-di-(R)-
MTPA ester by treatment with (R)-2-methoxy-2-trifluoro-
methylphenylacetic acid [(R)-MTPA] in the presence of
1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC‚
HCl) and 4-dimethylaminopyridine (4-DMAP). On the other hand,
the 3-(S)- and 9-(S)-MTPA esters (1c, 1e) and 3,9-di-(S)-MTPA
ester were obtained from 1a using (S)-MTPA in the presence of
EDC‚HCl and 4-DMAP. As shown in Figure 1, the signals due to
protons attached to the 4-, 5-, and 13-positions in the 3-(S)-MTPA
ester (1c) were observed at lower fields compared with those of
the 3-(R)-MTPA ester (1b) [∆δ: positive], while the signals due
to protons on the 2-, 11-, and 12-positions in 1c were observed at
higher fields compared with those of 1b [∆δ: negative]. Thus, the
absolute configuration at the 3-position of 1a was determined to
be R. The signals due to protons attached to the 5-8- and 11-
13-positions in the 9-(S)-MTPA ester (1e) were observed at lower
fields compared with those of the 9-(R)-MTPA ester (1d) [∆δ:
positive], while the signal of the 10-carboxy methyl proton in 1e
was observed at higher field compared with that of 1d [∆δ:
negative]. Consequently, the absolute configuration at the 9-position
of 1a was determined to be R and the absolute configurations of 1
and 1a were elucidated as shown.
Results and Discussion
The fresh whole plant of S. sarmentosum was extracted with
hot H2O, and the H2O extract was further treated with MeOH to
give a MeOH-soluble extract (0.57% from the fresh plant). The
MeOH-soluble extract was subjected to Diaion HP-20 column
chromatography (H2O f MeOH) to give H2O- and MeOH-eluted
fractions (0.44 and 0.13%, respectively). The MeOH-eluted fraction
was subjected to normal- and reversed-phase column chromatog-
raphies and finally HPLC to give 1-8 together with (3S,5R,6S,9R)-
megastigmane-3,9-diol25 (9), staphylionoside D26 (10), myrsinion-
osides A25 (11) and D25 (12), alangiosides A27 (13) and J25 (14),
3-hydroxy-5,6-epoxy-â-ionol 9-O-â-D-glucopyranoside28 (15), and
platanionoside D29 (16).
Sarmentoic acid (1) was obtained as an amorphous powder
([R]27D -3.3 in MeOH). The IR spectrum of 1 showed absorption
bands at 3364 and 1713 cm-1 ascribable to hydroxyl and carboxyl
functions. In the positive-ion FABMS of 1, a quasimolecular ion
peak was observed at m/z 267 [M + Na]+, and HRFABMS analysis
revealed the molecular formula of 1 to be C13H24O4. The 1H
(pyridine-d5, Table 1) and 13C NMR (Table 2) spectra of 1, which
were assigned by various NMR experiments,30 showed signals
assignable to three methyls [δ 1.03, 1.34 (both s, H3-12, 11), 1.07
(d, J ) 6.7 Hz, H3-13)], two methines bearing an oxygen function
[δ 4.29 (m, H-3), 4.73 (dd, J ) 4.0, 7.6 Hz, H-9)], and a carboxyl
carbon [δC 178.2 (C-10)] together with four methylenes, two
methines, and a quaternary carbon. As shown in Figure S1
(Supporting Information), the 1H-1H COSY experiment on 1
indicated the presence of a partial structure, written in bold lines,
Sarmentol A (2) was obtained as colorless oil ([R]27 -7.4 in
D
MeOH). The molecular formula, C13H26O3, of 2 was determined
from the positive-ion FABMS (m/z 253 [M + Na]+) and by
1
HRFABMS. The H (CD3OD, Table 1) and 13C NMR (Table 2)
spectra30 of 2 showed signals assignable to three methyls [δ 0.83,
0.96 (both s, H3-11, 12), 0.98 (d, J ) 6.5 Hz, H3-13)] and a
methylene and two methines bearing an oxygen function {δ [3.41
(dd, J ) 6.7, 11.0 Hz), 3.46 (dd, J ) 4.6, 11.0 Hz), H2-10], 3.53
(m, H-9), 3.69 (m, H-3)} together with four methylenes, two
methines, and a quaternary carbon. The proton and carbon signals
in the 1H and 13C NMR spectra of 2 resembled those of 1f, which
was derived from 1a by reduction with sodium borohydride
1
(NaBH4). As shown in Figure S1, the H-1H COSY experiment
* To whom correspondence should be addressed. Tel: +81-75-595-4633.
Fax: +81-75-595-4768. E-mail: myoshika@mb.kyoto-phu.ac.jp.
† Kyoto Pharmaceutical University.
on 2 indicated the partial structure written in bold lines, and the
carbon skeleton and the positions of functional groups were
characterized by the HMBC experiment, which showed long-range
correlations between the following: H2-2 and C-1; H-3 and C-2,
‡ Pharmaceutical Research and Technology Institute, Kinki University.
§ School of Pharmacy, Kinki University.
10.1021/np068059s CCC: $37.00
© 2007 American Chemical Society and American Society of Pharmacognosy
Published on Web 02/10/2007

576 Journal of Natural Products, 2007, Vol. 70, No. 4
Yoshikawa et al.
Chart 1
Table 1. 1H NMR (500 MHz) Data of 1 and 2 and Related Compounds (1a and 1f)
1a
1aa
1ab
1fb
2b
2c
position
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δH (J Hz)
2R
1.42 (br dd, ca. 3,
14)
1.42 (br dd, ca. 3,
14)
1.38 (br dd, ca.
3, 15)
1.39 (br dd, ca.
3, 14)
1.10 (dd, 11.9,
11.9)
1.08 (dd, 11.6,
11.6)
2â
1.81 (m)
1.82 (ddd, 2.0,
2.0, 14.3)
4.29 (m)
1.28 (ddd, 2.8,
13.2, 14.7)
1.97 (ddd, 3.1,
5.5, 14.7)
1.58 (m)
1.59 (ddd, 2.0,
2.0, 13.7)
4.09 (m)
1.69 (ddd, 2.8, 4.3,
11.9)
3.76 (m)
0.93 (ddd, 12.2,
12.2, 12.2)
1.92 (m)
1.63 (m)
3
4R
4.29 (m)
4.08 (m)
1.24 (m)
3.69 (m)
1.28 (ddd, 2.8,
13.2, 14.7)
1.97 (ddd, 3.1, 5.5,
14.7)
1.24 (m)
0.90 (ddd, 12.1,
12.1, 12.1)
1.89 (m)
4â
1.75 (ddd, 2.8, 5.5,
13.7)
1.73 (ddd, 2.8,
5.5, 13.7)
5
6
2.12 (m)
0.78 (ddd, 2.2, 5.8,
10.8)
2.13 (m)
0.72 (ddd, 2.1, 5.8,
10.8)
1.80 (m)
0.62 (ddd, 2.2, 5.8,
10.8)
1.80 (m)
0.62 (ddd, 2.1,
4.6, 9.2)
1.46 (m)
0.55 (ddd, 1.9, 4.9,
10.7)
1.45 (m)
0.54 (ddd, 2.1,
5.2, 12.6)
7
8
1.72 (m)
2.05 (m)
2.19 (m)
1.57 (m)
1.94 (m)
2.03 (m)
1.20 (m)
1.60 (m)
1.72 (m)
1.31 (m)
1.46 (m)
1.37 (m)
1.05 (m)
1.57 (m)
1.40 (m)
1.03 (m)
1.65 (m)
1.32 (m)
2.22 (m)
2.15 (m)
1.79 (m)
1.68 (m)
1.55 (m)
1.61 (m)
9
4.73 (dd, 4.0, 7.6)
4.59 (dd, 4.0, 7.7)
4.17 (dd, 4.0, 7.7)
3.69 (m)
3.67 (m)
3.53 (m)
10
3.45 (dd, 5.7, 10.3)
3.66 (dd, 2.3, 10.3)
1.03 (s)
3.44 (dd, 8.2, 11.6)
3.67 (dd, 3.1, 11.6)
0.81 (s)
3.41 (dd, 6.7, 11.0)
3.46 (dd, 4.6, 11.0)
0.83 (s)
11
1.34 (s)
1.32 (s)
1.02 (s)
12
1.03 (s)
0.99 (s)
0.90 (s)
0.89 (s)
0.95 (s)
0.96 (s)
13
COOMe
1.07 (d, 6.7)
1.01 (d, 6.7)
3.75 (s)
0.92 (d, 6.7)
3.80 (s)
0.95 (d, 6.9)
0.98 (d, 6.5)
0.98 (d, 6.5)
b
c
a Measured in pyridine-d5. Measured in CDCl3. Measured in CD3OD.
4; H-6 and C-1; H2-8 and C-9, 10; H-9 and C-8, 10; H2-10 and
C-8, 9; H3-11 and C-1, 2, 6, 12; H3-12 and C-1, 2, 6, 11; H3-13
and C-4-6. On the basis of this evidence, the planar structure of
2 was the same as that of 1f. Next, the relative stereostructure of
2 was determined by a NOESY experiment, in which correlations
were observed between HR-2 and H-6, H3-12; Hâ-2 and H-3; H-3
and Hâ-4; HR-4 and H-6, H3-13; H-6 and H3-12; and H2-7 and
H3-11. Finally, the absolute configuration of 2 was clarified by a
modified Mosher’s method.31 As shown in Figure 2, treatment of
2 with pivaloyl chloride in pyridine yielded the 10-pivaloyl and
3,10-dipivaloyl esters (2a, 2b). The 10-pivaloyl ester (2a) selectively
gave the 3-MTPA esters (2c, 2d) by steric hindrance due to the
10-pivaloyl group. In contrast, the 9-MTPA esters (2e, 2f) were
obtained from 2b in low yields. The protons on the 2-, 11-, and
12-positions of the 3-(S)-MTPA ester (2d) resonated at lower fields
than those of the 3-(R)-MTPA ester (2c) [∆δ: positive], while the
protons on the 4-, 5-, and 13-positions of 2d were observed at higher
fields compared to those of 2c [∆δ: negative]. On the other hand,
the 10-proton and pivaloyl methyl protons of the 9-(S)-MTPA ester
(2f) resonated at lower fields than those of the 9-(R)-MTPA ester
(2e) [∆δ: positive], while the protons on the 5-8- and 11-13-
positions of 2f were observed at higher fields compared to those
of 2e [∆δ: negative]. Consequently, the absolute configurations
at the 3- and 9-positions in 2 were elucidated to be 3S and 9S.
Sedumoside A1 (3) was obtained as an amorphous powder ([R]22
D
-28.3 in MeOH). HRFABMS revealed the molecular formula of
3 to be C19H36O8, and the IR spectrum showed absorption bands at
3389 and 1078 cm-1, ascribable to hydroxyl and ether functions.
The 1H NMR (pyridine-d5, Table 3) and 13C NMR (Table 4)
spectra30 of 3 showed the presence of the following functions: three
methyls [δ 0.75, 0.92 (both s, H3-11, 12), 0.92 (d, J ) 6.1 Hz,
H3-13)], a methylene and two methines bearing an oxygen function
{δ [3.52 (dd, J ) 5.8, 11.9 Hz), 3.65 (dd, J ) 3.4, 11.9 Hz), H2-
10], 4.05 (m, H-9), 4.12 (m, H-3)}, and a â-glucopyranosyl part
[δ 5.02 (d, J ) 7.6 Hz, H-1′)]. The acid hydrolysis of 3 with 1 M
HCl liberated D-glucose, which was identified by HPLC analysis

Megastigmanes from Sedum sarmentosum
Journal of Natural Products, 2007, Vol. 70, No. 4 577
Table 2. 13C NMR (125 MHz) Data of 1 and 2 and Related
Compounds (1a and 1f)
Sedumoside B (6), [R]23D -15.7 (MeOH), was also obtained as
an amorphous powder. The molecular formula, C19H36O8, of 6 was
determined from the positive-ion FABMS and by HRFABMS. The
1a
1aa
1ab
1fb
2b
2c
1
proton and carbon signals in the H (CD3OD, Table 5) and 13C
position
δC
δC
δC
δC
δC
δC
NMR (Table 6) spectra30 of 6 were very similar to those of 4, except
for the signals around the 9-position: three methyls [δ 0.83, 0.96
(both s, H3-11, 12), 0.99 (d, J ) 6.4 Hz, H3-13)], a methylene and
two methines bearing an oxygen function [δ 3.59 (2H, d-like, H2-
10), 3.65 (m, H-9), 3.69 (m, H-3)], and a â-glucopyranosyl part [δ
4.33 (d, J ) 8.0 Hz, H-1′)]. Acid hydrolysis of 6 liberated D-glucose.
The enzymatic hydrolysis of 6 with â-glucosidase gave a new
megastigmane, sarmentol B (6a), the 9R isomer of 2, as determined
by the chemical correlation with 8 (Vide infra). The linkage of the
â-D-glucopyranosyl moiety in 6 was clarified by the HMBC
experiment, which showed long-range correlation between the 1′-
proton and 9-carbon (Figure S1). Consequently, 6 was elucidated to
be sarmentol B 9-O-â-D-glucopyranoside.
1
2
3
4
5
6
7
8
34.8
48.0
66.7
44.4
29.7
53.7
25.5
37.6
71.7
178.2
23.5
31.9
21.2
34.8
48.0
66.7
44.3
29.7
53.6
25.3
37.3
71.5
176.0
23.5
31.8
21.1
51.6
34.2
47.4
67.8
43.1
28.8
53.1
24.1
36.3
70.7
175.8
23.1
31.4
20.6
52.5
34.2
47.4
67.8
43.1
28.8
53.3
24.9
35.3
72.6
66.9
23.1
31.4
20.8
35.9
51.0
66.9
45.6
33.6
52.7
24.9
35.5
72.8
66.7
21.0
30.7
21.5
36.8
51.8
67.3
46.5
34.9
54.2
26.3
36.9
73.9
67.3
21.4
31.3
21.5
9
10
11
12
13
COOMe
a Measured in pyridine-d5. Measured in CDCl3. Measured in
CD3OD.
b
c
Sedumoside C (7) was obtained as an amorphous powder ([R]27
D
-0.8 in MeOH). The IR spectrum of 7 showed absorption bands
at 3432, 1702, and 1061 cm-1, ascribable to hydroxyl, carbonyl,
and ether functions. The molecular formula, C19H34O8, of 7 was
from FABMS (m/z 413 [M + Na]+) and HRFABMS. Sedumoside
D (8), [R]27 -1.4 (MeOH), was also obtained as an amorphous
D
powder (C19H34O8). Treatment of 7 and 8 with 1 M HCl liberated
D-glucose. The 1H (CD3OD, Table 5) and 13C NMR (Table 6)
spectra30 of 7 showed signals assignable to three methyls [δ 0.77,
1.08 (both s, H3-11, 12), 1.09 (d, J ) 6.1 Hz, H3-13)], a methylene
and a methine bearing an oxygen function {δ [3.40 (dd, J ) 8.0,
10.5 Hz), 3.93 (dd, J ) 3.4, 10.5 Hz), H2-10], 3.75 (m, H-9)}, and
a â-glucopyranosyl moiety [δ 4.28 (d, J ) 7.7 Hz, H-1′)] together
with four methylenes, two methines, and two quaternary carbons
including an carbonyl carbon (δC 214.2, C-3). The 1H and 13C NMR
spectra of 7 were superimposable on those of 5, except for signals
due to the 3-position. The 1H-1H COSY experiment on 7 indicated
the presence of partial structures, written in bold lines, and in the
HMBC experiment, long-range correlations were observed between
H2-2 and C-1, 3; H2-4 and C-3; H-6 and C-1; H-9 and C-7, 8, 10;
H3-11 and C-1, 2, 6, 12; H3-12 and C-1, 2, 6, 11; H3-13 and C-4-
6; and H-1′ and C-10. In the NOESY experiment on 7, NOE
correlations were observed between the following: HR-2 and H3-
12; Hâ-2 and H3-11; HR-4 and H-6, H3-13; H-5 and H3-11; H-6
and H3-12; H2-7 and H3-11. Enzymatic hydrolysis of 7 with
â-glucosidase gave a new megastigmane, sarmentol C (7a), as the
aglycon. By the application of the octant rule for 7 and 7a, the
absolute configurations of the 5-positions were confirmed to be R.
That is, the circular dichroic (CD) spectra of 7 and 7a showed a
positive Cotton effect [7: 284 nm (∆ꢀ +0.08); 7a: 286 nm (∆ꢀ
+0.19), both in MeOH].25,32 Finally, reduction of 7 with NaBH4
yielded 5 and 7b in an approximate 7:2 ratio, so that the
configuration of the 9-position in 7 was clarified to be S.
Figure 1.
using an optical rotation detector.12,14-16,19-22,24 Enzymatic hydroly-
sis of 3 with â-glucosidase gave 2 as an aglycon. The position of
the â-D-glucopyranosyl moiety in 3 was determined by the HMBC
experiment, in which a long-range correlation was observed between
the 1′-proton and the 3-carbon. Consequently, the structure of 3
was elucidated as sarmentol A 3-O-â-D-glucopyranoside.
Sedumosides A2 (4) and A3 (5) were obtained as amorphous
powders (4: [R]27 -6.2; 5: [R]27 -16.9, both in MeOH). The
D
D
same molecular formula, C19H36O8, for both 4 and 5 was determined
individually from the positive-ion FABMS (m/z 415 [M + Na]+)
and by HRFABMS. Acid hydrolysis of 4 and 5 with 1 M HCl
liberated D-glucose. Enzymatic hydrolysis of 4 and 5 with â-glu-
cosidase both gave 2 as the aglycon. The 1H (pyridine-d5, Table 3)
and 13C NMR (Table 4) spectra30 of 4 and 5 indicated the presence
of the following functions: an aglycon part {4: δ 0.83, 0.93 (both
s, H3-11, 12), 0.97 (d, J ) 6.2 Hz, H3-13), 3.79 (2H, m, H2-10),
3.97 (m, H-3), 4.10 (m, H-9); 5: δ 0.80, 0.94 (both s, H3-11, 12),
0.96 (d, J ) 6.4 Hz, H3-13), [3.89 (dd, J ) 8.6, 10.1 Hz), 4.27 (dd,
J ) 3.7, 10.1 Hz), H2-10], 4.02 (m, H-3), 4.14 (m, H-9)} and a
â-glucopyranosyl part [4: δ 5.12 (d, J ) 7.6 Hz, H-1′); 5: δ 5.00
(d, J ) 7.6 Hz, H-1′)]. In the HMBC experiment of 4, a long-
range correlation was observed between the 1′-proton and the
9-carbon, while a long-range correlation in the HMBC experiment
of 5 was observed between the 1′-proton and the 10-carbon. Thus,
4 and 5 were elucidated as sarmentol A 9-O-â-D-glucopyranoside
and sarmentol A 10-O-â-D-glucopyranoside, respectively.
1
The H (CD3OD, Table 5) and 13C NMR (Table 6) spectra30 of
8 indicated the same functional groups as those of 7. Enzymatic
hydrolysis of 8 with â-glucosidase gave a new megastigmane,
1
sarmentol D (8a), as the aglycon. The H-1H COSY experiment
on 8 indicated the partial structures written in bold lines, and the
carbon skeleton and the positions of functional groups were
determined by the HMBC experiment, which showed long-range
correlations between H2-2 and C-1; H-3 and C-2, 4; H-6 and C-1;
H2-7 and C-9; H2-8 and C-9; H2-10 and C-9; H3-11 and C-1, 2, 6,
12; H3-12 and C-1, 2, 6, 11; H3-13 and C-4-6; and H-1′ and C-10.
Consequently, the â-glucopyranosyl group in 8 was at the 10-
position of 8a. The relative structure of 8 was characterized by the
NOESY experiment, which showed NOE correlations between
HR-2 and H-6, H3-12; Hâ-2 and H-3; H-3 and Hâ-4; HR-4 and
H-6, H3-13; H-6 and H3-12, H3-13; and H2-7 and H3-11. The (R)-
and (S)-MTPA esters (8b, 8c) were obtained from 8a using (R)-
and (S)-MTPA in the presence of EDC‚HCl and 4-DMAP,

578 Journal of Natural Products, 2007, Vol. 70, No. 4
Yoshikawa et al.
Figure 2.
Table 3. 1H NMR (500 MHz) Data of 3-5
3a
3b
4a
4b
5a
5b
position
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
1.09 (dd, 12.0,
12.0)
2R
1.29 (dd, 12.2,
12.2)
1.14 (dd, 11.9,
11.9)
1.36 (dd, 12.0,
12.0)
1.08 (dd, 11.9,
11.9)
1.39 (dd, 12.0,
12.0)
2â
2.03 (ddd, 1.9, 3.5,
12.2)
1.79 (ddd, 2.2, 4.1,
11.9)
1.90 (m)
1.63 (m)
1.92 (ddd, 2.8,
4.5, 12.0)
1.64 (ddd, 2.5,
4.5, 12.0)
3
4R
4.12 (m)
3.84 (m)
3.97 (m)
1.17 (m)
3.69 (m)
4.02 (m)
3.69 (m)
1.20 (ddd, 11.3,
11.3, 11.3)
2.21 (m)
1.03 (ddd, 12.2,
12.2, 12.2)
2.01 (m)
0.91 (ddd, 12.2,
12.2, 12.2)
1.89 (m)
1.21 (ddd, 11.3,
11.3, 11.3)
2.12 (m)
0.90 (ddd, 12.2,
12.2, 12.2)
1.89 (m)
4â
5
2.10 (m)
1.35 (m)
1.28 (m)
1.45 (m)
1.44 (m)
1.35 (m)
1.43 (m)
6
0.57 (ddd, 2.2,
4.6, 10.7)
1.18 (m)
1.83 (m)
1.65 (m)
0.56 (ddd, 2.1,
5.2, 11.0)
1.03 (m)
1.65 (m)
1.33 (m)
0.53 (ddd, 2.2,
5.3, 11.7)
1.18 (m)
1.89 (m)
1.77 (m)
0.53 (ddd, 2.1,
5.2, 12.6)
1.08 (m)
1.65 (m)
1.57 (m)
0.53 (ddd, 2.5,
5.0, 11.0)
1.16 (m)
1.82 (m)
1.60 (m)
0.53 (ddd, 2.8,
4.0, 10.7)
1.06 (m)
1.63 (m)
1.41 (m)
7
8
1.89 (m)
1.61 (m)
1.85 (m)
1.64 (m)
1.75 (m)
1.57 (m)
9
4.05 (m)
3.52 (m)
4.10 (m)
3.69 (m)
4.14 (m)
3.71 (m)
10
3.52 (dd, 5.8, 11.9)
3.65 (dd, 3.4, 11.9)
0.75 (s)
3.41 (dd, 6.7, 11.0)
3.46 (dd, 4.3, 11.0)
0.84 (s)
3.79 (2H, m)
3.52 (dd, 5.8, 11.9)
3.65 (dd, 3.4, 11.9)
0.83 (s)
3.89 (dd, 8.6, 10.1)
4.27 (dd, 3.7, 10.1)
0.80 (s)
3.37 (dd, 7.8, 10.1)
3.92 (dd, 2.7, 10.1)
0.83 (s)
11
12
13
Glc-1′
2′
0.83 (s)
0.93 (s)
0.97 (d, 6.2)
5.12 (d, 7.6)
4.03 (m)
0.92 (s)
0.97 (s)
0.97 (s)
0.94 (s)
0.96 (s)
0.92 (d, 6.1)
5.02 (d, 7.6)
4.05 (m)
4.30 (m)
4.28 (m)
0.98 (d, 6.1)
4.34 (d, 7.6)
3.12 (dd, 7.6, 9.2)
3.35 (dd, 9.2, 9.2)
3.25 (m)
0.98 (d, 6.5)
4.42 (d, 7.7)
3.20 (dd, 7.7, 9.2)
3.33 (dd, 9.2, 9.2)
3.27 (m)
0.96 (d, 6.1)
5.00 (d, 7.6)
4.09 (dd, 7.6, 9.0)
4.24 (m)
0.97 (d, 6.4)
4.27 (d, 7.6)
3.21 (dd, 7.6, 9.2)
3.33 (m)
3′
4′
4.20 (m)
4.19 (m)
4.24 (m)
3.27 (m)
5′
4.00 (m)
3.27 (m)
3.90 (m)
3.27 (m)
3.99 (m)
3.25 (m)
6′
4.33 (dd, 4.9, 11.9)
4.58 (dd, 3.1, 11.9)
3.65 (dd, 4.9, 11.6)
3.86 (dd, 2.1, 11.6)
4.34 (dd, 4.8, 11.6)
4.48 (dd, 2.1, 11.6)
3.64 (m)
3.85 (dd, 2.2, 12.0)
4.37 (dd, 5.5, 11.9)
4.56 (br d, ca. 12)
3.64 (m)
3.86 (dd, 1.6, 10.1)
b
a Measured in pyridine-d5. Measured in CD3OD.
LA500 (500 MHz) spectrometer; 13C NMR spectra, JEOL JNM-LA500
(125 MHz) spectrometer with tetramethylsilane as an internal standard;
EIMS, CIMS, HREIMS, and HRCIMS, JEOL JMS-GCMATE mass
spectrometer; FABMS and HRFABMS, JEOL JMS-SX 102A mass
spectrometer; HPLC detector, Shimadzu RID-6A refractive index and
SPD-10A UV-vis detectors; HPLC, Cosmosil 5C18-MS-II columns
(Nacalai Tesque Inc., 250 × 4.6 mm i.d. and 250 × 20 mm i.d. for
analytical and preparative purposes, respectively).
The following experimental conditions were used for chromatogra-
phy: normal-phase silica gel column chromatography (CC), silica gel
BW-200 (Fuji Silysia Chemical, Ltd., 150-350 mesh); reversed-phase
silica gel CC, Chromatorex ODS DM1020T (Fuji Silysia Chemical,
Ltd., 100-200 mesh); Diaion HP-20 CC (Nippon Rensui); Sephadex
LH-20 CC (Amersham Biosciences K. K.); preparative TLC, precoated
TLC plates with silica gel 60F254 (Merck, 0.25 mm) (normal-phase);
TLC, precoated TLC plates with silica gel 60F254 (Merck, 0.25 mm)
(normal-phase) and silica gel RP-18 F254S (Merck, 0.25 mm) (reversed-
phase); reversed-phase HPTLC, precoated TLC plates with silica gel
respectively. The protons on the 2-, 11-, and 12-positions of the
(S)-MTPA ester (8c) resonated at lower fields than those of the
(R)-MTPA ester (8b) [∆δ: positive], while the protons on the 4-,
5-, and 13-positions of 8c were observed at higher fields compared
to those of 8b [∆δ: negative]. Finally, reduction of the 9-carbonyl
group in 8 with NaBH4 gave 5 and its 9-diastereoisomer (8d) in an
approximate 1:1 ratio. Enzymatic hydrolysis of 8d with â-glucosi-
dase gave 6a, and thus the absolute configuration of 6a was also
clarified. On the basis of this evidence, the absolute configurations
of 6 and 8 were elucidated to be as shown.
Experimental Section
General Experimental Procedures. The following instruments were
used to obtain physical data: specific rotations, Horiba SEPA-300
digital polarimeter (l ) 5 cm); CD spectra, JASCO J-720WI spec-
trometer; UV spectra, Shimadzu UV-1600 spectrometer; IR spectra,
Shimadzu FTIR-8100 spectrometer; 1H NMR spectra, JEOL JNM-

Megastigmanes from Sedum sarmentosum
Journal of Natural Products, 2007, Vol. 70, No. 4 579
Table 4. 13C NMR (125 MHz) Data of 3-5
further separated by HPLC [CH3CN-H2O (15:85, v/v)] to furnish 3
(34.0 mg, 0.00006%), 4 (838.6 mg, 0.0016%), 5 (200.9 mg, 0.00024%),
sedumoside C (7, 24.1 mg, 0.00005%), and 8 (220.5 mg, 0.00041%).
Fraction 2-8 (1800 mg) was purified by Sephadex LH-20 CC [150 g,
CHCl3-MeOH (1:1, v/v)] and finally HPLC [CH3CN-MeOH-H2O
(20:8:72, v/v/v) and MeOH-H2O (40:60, v/v)] to furnish sarmentoic
acid (1, 429.8 mg, 0.00080%), 1a (24.5 mg, 0.00005%), and alangioside
J (14, 80.9 mg, 0.00015%). Fraction 2-10 (1360 mg) was further
separated by HPLC [CH3CN-MeOH-H2O (20:8:72, v/v/v) and
CHCl3-MeOH (40:60, v/v)] to furnish myrsinionoside D (12, 182.1
mg, 0.00034%) and 14 (21.2 mg, 0.00004%). Fraction 3 (10.4 g) was
subjected to reversed-phase silica gel CC [240 g, MeOH-H2O (10:90
f 20:80 f 30:70 f 40:60, v/v) f MeOH] to afford 14 fractions [3-1
(123.0 mg), 3-2 (675.1 mg), 3-3 (574.8 mg), 3-4 (1337 mg), 3-5 (797.8
mg), 3-6 (798.6 mg), 3-7 (230.3 mg), 3-8 (901.2 mg), 3-9 (645.6 mg),
3-10 (256.4 mg), 3-11 (511.7 mg), 3-12 (1238 mg), 3-13 (473.1 mg),
and 3-14 (1320 mg)]. Fraction 3-9 (645.6 mg) was purified by Sephadex
LH-20 CC [150 g, CHCl3-MeOH (1:1, v/v)] and finally HPLC
[MeOH-H2O (32:68, v/v)] to give plantaninoside D (16, 17.7 mg,
0.00003%). The known compounds were identified by comparison of
3a
3b
4a
4b
5a
5b
position
δC
δC
δC
δC
δC
δC
1
2
3
4
5
6
7
8
35.8
48.1
74.2
44.3
33.9
53.1
25.7
36.9
73.3
67.5
21.0
30.9
21.1
103.0
75.4
78.7
71.8
78.5
62.9
36.7
48.4
75.7
44.7
34.9
54.3
26.3
36.9
73.9
67.2
21.3
31.3
21.5
102.6
75.0
78.0
71.7
77.8
62.8
36.0
51.9
66.0
46.6
33.9
53.3
25.3
35.0
82.8
65.0
21.2
31.0
21.3
104.5
75.7
78.4
71.7
78.2
62.8
36.8
51.8
67.4
46.5
34.9
54.4
26.1
35.2
82.5
64.8
21.4
31.4
21.5
103.9
75.6
78.1
71.7
77.9
62.9
35.9
52.1
66.0
46.8
34.0
53.1
25.5
36.5
71.4
75.8
21.3
31.0
21.3
105.5
75.4
78.6
71.7
78.6
62.8
36.8
51.8
67.4
46.5
34.9
54.2
26.1
36.8
72.4
75.5
21.3
31.4
21.5
104.8
75.2
77.9
71.6
78.0
62.7
9
10
11
12
13
Glc-1′
2′
3′
4′
5′
6′
1
their physical data ([R]D, IR, H NMR, 13C NMR, MS] with reported
values.25-29
Sarmentoic acid (1): amorphous powder; [R]27 -3.3 (c 1.02,
D
b
a Measured in pyridine-d5. Measured in CD3OD.
MeOH); IR (KBr) νmax 3364, 2971, 2922, 2512, 1713, 1470, 1294,
1267, 1192, 1113, 1080, 1042, 948, 793, 650 cm-1; 1H NMR data, see
Table 1; 13C NMR data, see Table 2; positive-ion FABMS m/z 267 [M
+ Na]+; HRFABMS m/z 267.1579 (calcd for C13H24O4Na [M + Na]+,
267.1572).
RP-18 WF254S (Merck, 0.25 mm); detection was achieved by spraying
with 1% Ce(SO4)2-10% aqueous H2SO4, followed by heating.
Plant Material. S. sarmentosum was cultivated at Huangshan, Anhui
Province, China, and plant material was identified by one of the authors
(M.Y.). A voucher specimen (2005.01. Eishin-02) of this plant is on
file in our laboratory.
Sarmentol A (2): colorless oil; [R]27 -7.4 (c 0.10, MeOH); IR
D
(film) νmax 3389, 2926, 2874, 1472, 1387, 1026, 756 cm-1; H NMR
1
data, see Table 1; 13C NMR data, see Table 2; positive-ion FABMS
m/z 253 [M + Na]+; HRFABMS m/z 253.1774 (calcd for C13H26O3Na
[M + Na]+, 253.1780).
Extraction and Isolation. The hot H2O extract (1950 g) from the
fresh whole plant of S. sarmentosum (Huangshan, Anhui Province,
China, 1.25% from this herbal medicine) was extracted three times
with MeOH under reflux for 3 h. Evaporation of the solvent under
reduced pressure provided a MeOH extract (887.5 g, 0.57%), and an
aliquot (398.6 g) was subjected to Diaion HP-20 CC (4.0 kg, H2O f
MeOH, twice) to give H2O- and MeOH-eluted fractions (305.0 and
93.6 g, respectively). The MeOH-eluted fraction (72.0 g) was subjected
to normal-phase silica gel CC [2.0 kg, CHCl3-MeOH-H2O (10:3:0.5
f 7:3:1, v/v/v, lower layer) f MeOH] to give five fractions [1 (12.1
g), 2 (19.2 g), 3 (10.4 g), 4 (8.7 g), and 5 (16.3 g)]. Fraction 1 (12.1
g) was subjected to reversed-phase silica gel CC [300 g, MeOH-H2O
(5:95 f 10:90 f 20:80 f 30:70 f 50:50 f 70:30, v/v) f MeOH]
to afford 13 fractions [1-1 (550 mg), 1-2 (980 mg), 1-3 (1460 mg), 1-4
(1230 mg), 1-5 (1510 mg), 1-6 (1800 mg), 1-7 (540 mg), 1-8 (600
mg), 1-9 (710 mg), 1-10 (220 mg), 1-11 (1170 mg), 1-12 (1030 mg),
and 1-13 (150 mg)]. Fraction 1-5 (1510 mg) was purified by Sephadex
LH-20 CC [150 g, CHCl3-MeOH (1:1, v/v)] and finally HPLC
[MeOH-H2O (35:65, v/v)] to furnish sarmentol A (2, 125.8 mg,
0.00023%). Fraction 1-7 (540 mg) was purified by Sephadex LH-20
CC [150 g, CHCl3-MeOH (1:1, v/v)] and finally HPLC [MeOH-
H2O (40:60, v/v)] to furnish myrsinionoside A (11, 48.5 mg, 0.00009%).
Fraction 1-9 (710 mg) was purified by Sephadex LH-20 CC [150 g,
CHCl3-MeOH (1:1, v/v)] and finally HPLC [MeOH-H2O (50:50, v/v)]
to furnish (3S,5R,6S,9R)-megastigmane-3,9-diol (9, 14.8 mg, 0.00003%).
Fraction 2 (19.2 g) was subjected to reversed-phase silica gel CC [600
g, MeOH-H2O (20:80 f 30:70 f 40:60 f 70:30, v/v) f MeOH] to
afford 12 fractions [2-1 (200 mg), 2-2 (4630 mg), 2-3 (1160 mg), 2-4
(1950 mg), 2-5 (3300 mg), 2-6 (650 mg), 2-7 (700 mg), 2-8 (1800
mg), 2-9 (810 mg), 2-10 (1360 mg), 2-11 (2270 mg), and 2-12 (770
mg)]. Fraction 2-4 (1950 mg) was subjected to normal-phase silica gel
CC [100 g, CHCl3 f CHCl3-MeOH (50:1 f 20:1 f 10:1, v/v) f
CHCl3-MeOH-H2O (20:3:1, v/v/v, lower layer) f MeOH] to give
seven fractions [2-4-1 (90.5 mg), 2-4-2 (50.1 mg), 2-4-3 (284.0 mg),
2-4-4 (153.8 mg), 2-4-5 (348.2 mg), 2-4-6 (721.1 mg), and 2-4-7 (300.0
mg)]. Fraction 2-4-5 (348.2 mg) was further purified by HPLC [CH3-
CN-MeOH-H2O (10:8:82, v/v/v) and MeOH-H2O (30:70 or 32:68,
v/v)] to furnish sedumoside D (8, 43.0 mg, 0.00008%), staphylionoside
D (10, 3.2 mg, 0.00001%), and 3-hydroxy-5,6-epoxy-â-ionol 9-O-â-
D-glucopyranoside (15, 22.0 mg, 0.00004%). Fraction 2-4-6 (721.1 mg)
was further purified by HPLC [MeOH-H2O (32:68, v/v)] to give
sedumosides A1 (3, 162.5 mg, 0.00030%), A2 (4, 60.6 mg, 0.00011%),
A3 (5, 29.2 mg, 0.00005%), and B (6, 3.2 mg, 0.00001%) and
alangioside A (13, 52.8 mg, 0.00010%). Fraction 2-5 (3300 mg) was
Sedumoside A1 (3): amorphous powder; [R]22 -28.3 (c 1.64,
D
MeOH); IR (KBr) νmax 3389, 2930, 2876, 1474, 1368, 1163, 1078,
1022 cm-1; H NMR data, see Table 3; 13C NMR data, see Table 4;
1
positive-ion FABMS m/z 415 [M + Na]+; HRFABMS m/z 415.2313
(calcd for C19H36O8Na [M + Na]+, 415.2308).
Sedumoside A2 (4): amorphous powder; [R]27 -6.2 (c 1.69,
D
MeOH); IR (KBr) νmax 3410, 2918, 1508, 1474, 1377, 1165, 1076,
1022 cm-1; H NMR data, see Table 3; 13C NMR data, see Table 4;
1
positive-ion FABMS m/z 415 [M + Na]+; HRFABMS m/z 415.2313
(calcd for C19H36O8Na [M + Na]+, 415.2308).
Sedumoside A3 (5): amorphous powder; [R]27 -16.9 (c 0.95,
D
MeOH); IR (KBr) νmax 3389, 2940, 1561, 1522, 1474, 1175, 1085,
1032 cm-1; H NMR data, see Table 3; 13C NMR data, see Table 4;
1
positive-ion FABMS m/z 415 [M + Na]+; HRFABMS m/z 415.2303
(calcd for C19H36O8Na [M + Na]+, 415.2308).
Sedumoside B (6): amorphous powder; [R]23 -15.7 (c 0.16,
D
MeOH); IR (KBr) νmax 3390, 2928, 2876, 1474, 1078, 1022 cm-1; 1H
NMR data, see Table 5; 13C NMR data, see Table 6; positive-ion
FABMS m/z 415 [M + Na]+; HRFABMS m/z 415.2313 (calcd for
C19H36O8Na [M + Na]+, 415.2308).
Sedumoside C (7): amorphous powder; [R]27D -0.8 (c 0.82, MeOH);
CD (MeOH) λmax (∆ꢀ) 284 (+0.08); IR (KBr) νmax 3432, 2958, 1702,
1653, 1474, 1100, 1061 cm-1; H NMR data, see Table 5; 13C NMR
1
data, see Table 6; positive-ion FABMS m/z 413 [M + Na]+;
HRFABMS m/z 413.2153 (calcd for C19H34O8Na [M + Na]+, 413.2151).
Sedumoside D (8): amorphous powder; [R]27D -1.4 (c 2.01, MeOH);
IR (KBr) νmax 3432, 2961, 1719, 1655, 1647, 1561, 1541, 1474, 1079,
1051 cm-1; H NMR data, see Table 5; 13C NMR data, see Table 6;
1
positive-ion FABMS m/z 413 [M + Na]+; HRFABMS m/z 413.2147
(calcd for C19H34O8Na [M + Na]+, 413.2151).
Methylation of 1.18 A solution of 1 (20.0 mg) in Et2O-MeOH (1:
1, v/v, 1.0 mL) was treated with trimethylsilyldiazomethane (TM-
SCHN2, 10% in hexane, ca. 0.3 mL), and the whole was stirred at room
temperature for 16 h. Removal of the solvent under reduced pressure
furnished a residue, which was purified by normal-phase silica gel CC
[2.0 g, hexane f hexane-CHCl3 (1:1, v/v) f CHCl3] to give 1a (18.0
mg, 85%).
Compound 1a: colorless oil; [R]27D -6.4 (c 2.01, MeOH); IR (film)
νmax 3432, 2953, 2940, 1717, 1541, 1472, 1259, 1165, 1076, 1038,
899, 752 cm-1; H NMR data, see Table 1; 13C NMR data, see Table
1
2; EIMS m/z 258 [M]+ (1), 240 (8), 225 (20), 123 (100); HREIMS m/z
258.1825 (calcd for C14H26O4, 258.1831).

580 Journal of Natural Products, 2007, Vol. 70, No. 4
Yoshikawa et al.
Table 5. 1H NMR (500 MHz) Data of 6-8 and Related Compounds (6a-8a and 8d)
6a
6aa
6ab
7a
7ab
position
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
2R
2â
1.08 (dd, 11.6, 11.6)
1.64 (m)
1.09 (dd, 11.9, 11.9)
1.64 (ddd, 2.5,
4.3, 11.9)
1.10 (dd, 11.9, 11.9)
1.64 (ddd, 2.5,
4.3, 11.9)
2.38 (d, 13.2)
1.97 (dd, 2.4, 13.2)
2.28 (d, 13.1)
2.07 (dd, 2.5, 13.1)
3
3.69 (m)
3.69 (m)
3.77 (m)
4R
0.92 (ddd, 12.2,
12.2, 12.2)
1.88 (m)
0.90 (ddd, 12.2,
12.2, 12.2)
1.88 (m)
0.93 (ddd, 12.1,
12.1, 12.1)
1.92 (m)
2.15 (ddd, 0.9,
14.1, 14.1)
2.21 (ddd, 2.4,
4.6, 14.1)
1.78 (m)
1.16 (ddd, 2.5,
4.9, 11.3)
1.20 (m)
1.67 (m)
1.47 (m)
2.04 (m)
4â
2.31 (ddd, 2.5,
4.6, 14.1)
1.81 (m)
5
6
1.44 (m)
1.45 (m)
1.45 (m)
0.54 (ddd, 2.5,
5.2, 11.0)
1.24 (m)
1.46 (m)
0.53 (ddd, 3.1,
4.9, 11.3)
1.32 (m)
1.47 (m)
1.50 (m)
0.54 (ddd, 2.7,
5.8, 11.3)
1.28 (m)
1.47 (m)
1.49 (2H, m)
1.09 (m)
7
8
1.17 (m)
1.65 (m)
1.51 (m)
1.37 (m)
1.69 (m)
1.58 (m)
1.65 (m)
1.63 (m)
9
3.65 (m)
3.53 (m)
3.69 (m)
3.75 (m)
3.73 (m)
10
3.59 (2H, d-like)
3.42 (dd, 6.4, 11.0)
3.45 (dd, 4.6, 11.0)
0.83 (s)
0.96 (s)
0.99 (d, 6.4)
3.47 (dd, 6.4, 11.0)
3.66 (dd, 4.6, 11.0)
0.81 (s)
0.95 (s)
0.97 (d, 6.4)
3.40 (dd, 8.0, 10.5)
3.93 (dd, 3.4, 10.5)
0.77 (s)
3.47 (dd, 8.0, 11.0)
3.69 (dd, 3.3, 11.0)
0.78 (s)
1.06 (s)
1.07 (d, 6.1)
11
12
13
Glc-1′
2′
0.83 (s)
0.96 (s)
1.08 (s)
0.99 (d, 6.4)
4.33 (d, 8.0)
3.19 (dd, 8.0, 9.2)
3.33 (dd, 9.2, 9.2)
3.28 (m)
1.09 (d, 6.1)
4.28 (d, 7.7)
3.22 (dd, 7.7, 9.5)
3.36 (dd, 8.9, 9.5)
3.26 (m)
3′
4′
5′
3.28 (m)
3.28 (m)
6′
3.64 (m)
3.86 (dd, 2.2, 12.0)
3.66 (dd, 4.9, 11.9)
3.84 (dd, 1.6, 11.9)
8a
8c
8aa
8ab
8db
position
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
δ
H (J Hz)
2R
2â
1.09 (dd, 11.9, 11.9)
1.64 (ddd, 2.4,
4.0, 11.9)
1.36 (dd, 12.2, 12.2)
1.91 (ddd, 2.5,
4.3, 12.2)
1.09 (dd, 12.0, 12.0)
1.64 (ddd, 2.5,
4.0, 12.0)
1.11 (dd, 11.9, 11.9)
1.70 (ddd, 2.8, 4.3, 11.9)
1.09
1.64
3
4R
3.69 (m)
3.97 (m)
3.69 (m)
3.76 (m)
3.69
0.90
0.92 (ddd, 12.2,
12.2, 12.2)
1.88 (m)
1.35 (m)
060 (ddd, 2.8,
5.5, 11.0)
1.16 (ddd, 12.1,
12.1, 12.1)
2.08 (m)
1.35 (m)
0.53 (ddd, 2.7,
5.2, 11.0)
0.91 (ddd, 11.9,
11.9, 11.9)
1.88 (m)
1.35 (m)
0.59 (ddd, 2.5,
5.2, 10.7)
0.94 (ddd, 11.9,
11.9, 11.9)
1.94 (m)
1.48 (m)
0.57 (ddd, 2.8,
5.2, 11.0)
4â
5
6
1.89
1.43
0.54
7
8
1.47 (m)
1.74 (m)
2.54 (ddd, 6.1,
10.4, 16.8)
2.62 (ddd, 5.5,
11.6, 16.8)
1.41 (m)
1.80 (m)
2.64 (ddd, 5.8,
11.3, 17.7)
2.70 (ddd, 5.8,
11.5, 17.7)
1.48 (m)
1.74 (m)
2.43 (ddd, 6.1, 10.4,
16.8)
2.54 (ddd, 5.2, 11.0,
16.8)
1.41 (m)
1.76 (m)
2.40 (ddd, 6.1,
11.0, 16.5)
2.51 (ddd, 5.2,
11.3, 16.5)
1.26
1.46
1.48
1.57
9
10
4.28 (d, 17.4)
4.51 (d, 17.4)
0.83 (s)
4.57 (d, 16.8)
4.74 (d, 16.8)
0.78 (s)
0.89 (s)
0.87 (d, 6.4)
4.17 (2H, s)
4.23 (2H, s)
3.58
3.77
0.83
0.96
0.99
4.27
3.21
3.36
3.27
3.27
3.64
3.86
11
12
13
Glc-1′
2′
3′
4′
5′
6′
0.83 (s)
0.95 (s)
0.97 (d, 6.4)
0.83 (s)
0.94 (s)
0.96 (d, 6.4)
0.95 (s)
0.97 (d, 6.4)
4.29 (d, 7.1)
3.27 (m)
3.35 (m)
3.27 (m)
3.27
3.64 (m)
3.86 (dd, 2.2, 11.9)
4.95 (d, 7.1)
4.13 (dd, 7.1, 8.8)
4.25 (dd, 8.8, 8.8)
4.23 (dd, 8.8, 9.0)
3.94 (m)
4.38 (dd, 5.5, 11.9)
4.53 (br, d, ca. 12)
c
a Measured in CD3OD. b Measured in CDCl3. Measured in pyridine-d5.
Preparation of the (R)-MTPA Esters (1b, 1d) and (S)-MTPA
Esters (1c, 1e) from 1a. A solution of 1a (9.3 mg) in CH2Cl2 (2.0
mL) was treated with (R)-2-methoxy-2-trifluoromethylphenylacetic acid
[(R)-MTPA, 45.6 mg] in the presence of 1-ethyl-3-(3-dimethylamino-
propyl)carbodiimide hydrochloride (EDC‚HCl, 37.1 mg) and 4-dim-
ethylaminopyridine (4-DMAP, 15.7 mg), and the mixture was stirred
at room temperature for 16 h. The reaction mixture was poured into
ice-water and extracted with EtOAc. The EtOAc extract was succes-
sively washed with 5% aqueous HCl, saturated aqueous NaHCO3, and
brine, then dried over MgSO4 powder and filtered. Removal of the
solvent from the filtrate under reduced pressure furnished a residue,
which was purified by preparative TLC [CHCl3-acetone (20:1, v/v)]
to give 1b (1.2 mg, 7%), 1d (2.0 mg, 11%), and 3,9-di-(R)-MTPA
ester derivative of 1a (trace). Using a similar procedure, 1c (0.6 mg,
4%), 1e (1.8 mg, 12%), and 3,9-di-(S)-MTPA ester derivative of 1a
(trace) were obtained from 1a (7.7 mg) using (S)-MTPA (35.1 mg),
EDC‚HCl (32.9 mg), and 4-DMAP (13.4 mg).
1
Compound 1b: colorless oil; H NMR (pyridine-d5, 500 MHz) δ
0.61 (ddd, J ) 1.6, 5.2, 10.4 Hz, H-6), 0.85, 0.91 (3H each, both s,
H3-12, 11), 0.85 (3H, d, J ) 5.8 Hz, H3-13), 1.18 (1H, ddd, J ) 3.1,

Megastigmanes from Sedum sarmentosum
Journal of Natural Products, 2007, Vol. 70, No. 4 581
Table 6. 13C NMR (125 MHz) Data of 6-8 and Related Compounds (6a-8a and 8d)
6a
6aa
6ab
7a
7ab
8a
8c
8aa
8ab
8db
position
δC
δC
δC
δC
δC
δC
δC
δC
δC
δC
1
2
3
4
5
6
7
8
36.8
51.9
67.4
46.5
34.8
54.4
25.9
35.0
83.2
65.9
21.4
31.4
21.6
104.0
75.2
78.2
71.7
77.9
62.7
36.8
51.9
67.4
46.5
35.2
54.1
26.2
36.7
73.7
67.4
21.4
31.3
21.5
35.3
51.0
66.9
45.6
33.8
52.5
24.8
35.3
72.5
66.9
20.9
30.7
21.0
40.4
57.1
214.2
50.9
37.7
52.2
26.1
36.5
72.2
75.4
21.1
30.3
21.5
104.9
75.1
77.9
71.6
78.0
62.7
39.3
56.3
211.1
50.1
36.1
52.6
25.0
35.2
72.6
66.6
20.7
29.9
21.0
36.8
51.8
67.3
46.4
34.9
53.4
23.4
41.6
210.9
74.7
21.3
31.4
21.4
104.3
75.0
77.8
71.6
78.2
62.8
35.9
52.0
65.8
46.6
33.8
52.2
22.6
41.2
208.6
74.5
21.1
30.9
21.7
104.6
75.0
78.4
71.6
78.7
62.8
36.8
51.8
67.3
46.4
34.9
53.5
23.7
41.0
212.4
68.8
21.3
31.3
21.4
35.9
50.9
66.7
45.5
33.5
52.2
22.7
40.3
209.4
68.1
20.9
30.7
20.9
36.8
51.9
67.4
46.5
35.1
54.1
26.2
36.6
71.8
75.0
21.4
31.4
21.5
104.5
75.2
78.0
71.8
78.0
62.9
9
10
11
12
13
Glc-1′
2′
3′
4′
5′
6′
a Measured in CD3OD. b Measured in CDCl3. c Measured in pyridine-d5.
Figure 3.
12.5, 13.7 Hz, HR-4), 1.35 (1H, m, H-5), 1.37, 1.77 (1H each, both m,
H2-7), 1.42 (1H, br d, J ≈ 4, 15 Hz, HR-2), 1.77 (1H, ddd, J ) 2.1,
2.1, 14.7 Hz, Hâ-2), 1.86 (1H, ddd, J ) 3.1, 6.1, 13.7 Hz, Hâ-4), 1.93,
2.02 (1H each, both m, H2-8), 3.62, 3.74 (3H each, both s, -COOCH3),
4.53 (1H, m, H-9), 5.43 (1H, m, H-3), [7.41-7.45 (3H, m), 7.76 (2H,
dd-like), Ph-H].
H2-7), 1.25 (1H, ddd, J ) 3.2, 12.7, 14.4 Hz, HR-4), 1.36 (1H, br d, J
≈ 4, 15 Hz, HR-2), 1.56 (1H, ddd, J ) 2.7, 2.7, 14.7 Hz, Hâ-2), 1.64,
1.87 (1H each, both m, H2-8), 1.73 (1H, ddd, J ) 2.5, 4.9, 14.4 Hz,
Hâ-4), 2.08 (1H, m, H-5), 3.65, 3.76 (3H each, both s, -COOCH3),
4.08 (1H, m, H-3), 5.16 (1H, dd, J ) 3.4, 8.3 Hz, H-9), 7.39-7.61
(5H, m, Ph-H).
1
Compound 1c: colorless oil; H NMR (pyridine-d5, 500 MHz) δ
NaBH4 Reduction of 1a. A solution of 1a (18.9 mg) in MeOH-
pyridine (2:1, v/v, 1.5 mL) was treated with NaBH4 (4.0 mg), and the
mixture was stirred at room temperature for 3 h. The reaction mixture
was quenched in acetone, and then removal of the solvent under reduced
pressure gave a residue, which was purified by normal-phase silica gel
CC [hexane-EtOAc (5:1 f 1:1, v/v)] to give 1f (10.7 mg, 64%).
0.62 (ddd, J ) 1.8, 5.8, 10.7 Hz, H-6), 0.62, 0.85 (3H each, both s,
H3-12, 11), 0.93 (3H, d, J ) 5.8 Hz, H3-13), 1.26 (1H, ddd, J ) 3.2,
12.7, 14.4 Hz, HR-4), 1.37 (1H, br d, J ) 4, 15 Hz, HR-2), 1.40, 1.78
(1H each, both m, H2-7), 1.64 (1H, ddd, J ) 2.5, 2.5, 14.7 Hz, Hâ-2),
1.67 (1H, m, H-5), 1.91 (1H, ddd, J ) 2.5, 4.9, 14.4 Hz, Hâ-4), 1.95,
2.04 (1H each, both m, H2-8), 3.65, 3.74 (3H each, both s, -COOCH3),
4.55 (1H, m, H-9), 5.43 (1H, m, H-3), [7.42-7.46 (3H, m), 7.78 (2H,
dd-like), Ph-H].
Compound 1f: colorless oil; [R]27D +37.2 (c 1.30, MeOH); IR (film)
1
νmax 3375, 2922, 2874, 1473, 1387, 1026, 756 cm-1; H NMR data,
1
see Table 1; 13C NMR data, see Table 2; positive-ion FABMS m/z 253
[M + Na]+; HRFABMS m/z 253.1789 (calcd for C13H26O3Na [M +
Na]+, 253.1780).
Compound 1d: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.54
(ddd, J ) 1.8, 5.7, 10.6 Hz, H-6), 0.78, 0.93 (3H each, both s, H3-12,
11), 0.78 (3H, d, J ) 6.4 Hz, H3-13), 1.04, 1.42 (1H each, both m,
H2-7), 1.19 (1H, ddd, J ) 3.2, 12.4, 14.5 Hz, HR-4), 1.33 (1H, br d, J
≈ 4, 15 Hz, HR-2), 1.54 (1H, m, Hâ-2), 1.58, 1.81 (1H each, both m,
H2-8), 1.68 (1H, ddd, J ) 2.5, 4.8, 14.5 Hz, Hâ-4), 2.00 (1H, m, H-5),
3.66, 3.79 (3H each, both s, -COOCH3), 4.05 (1H, m, H-3), 5.16 (1H,
dd, J ) 3.4, 8.3 Hz, H-9), 7.39-7.69 (5H, m, Ph-H).
Pivaloylation of 2. A solution of 2 (36.8 mg) in pyridine (1.0 mL)
was treated with pivaloyl chloride (50 µL), and the mixture was stirred
at 60 °C for 6 h. The reaction mixture was poured into ice-water, and
the whole was extracted with EtOAc. The EtOAc extract was
successively washed with 5% aqueous HCl, saturated aqueous NaHCO3,
and brine, then dried over MgSO4 powder and filtered. Removal of
the solvent under reduced pressure furnished a resudue, which was
1
Compound 1e: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.61
(ddd, J ) 1.8, 5.8, 10.7 Hz, H-6), 0.84, 0.98 (3H each, both s, H3-12,
11), 0.88 (3H, d, J ) 6.7 Hz, H3-13), 1.22, 1.53 (1H each, both m,

582 Journal of Natural Products, 2007, Vol. 70, No. 4
Yoshikawa et al.
purified by normal-phase silica gel CC [1.5 g, hexane-EtOAc (20:1
f 10:1 f 5:1 f 3:1, v/v)] to give 2a (16.4 mg, 32%) and 2b (8.3 mg,
13%).
each, both s, -OCOC(CH3)3], 1.19 (1H, dd, J ) 12.0, 12.0 Hz, HR-
2), 1.51 (1H, m, H-5), 1.60, 1.78 (1H each, both m, H2-8), 1.66 (1H,
ddd, J ) 2.8, 4.0, 12.0 Hz, Hâ-2), 1.91 (1H, m, Hâ-4), 3.55 (3H, s,
-COOCH3), [4.06 (1H, dd, J ) 6.1, 12.5 Hz), 4.31 (1H, dd, J ) 3.1,
12.5 Hz), H2-10], 4.80 (1H, m, H-3), 5.23 (1H, m, H-9), 7.39-7.55
(5H, m, Ph-H).
1
Compound 2a: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.56
(ddd, J ) 2.5, 4.6, 11.1 Hz, H-6), 0.81, 0.95 (3H each, both s, H3-11,
12), 0.94 (1H, ddd, J ) 12.2, 12.2, 12.2 Hz, HR-4), 0.96 (3H, d, J )
6.7 Hz, H3-13), 1.07, 1.60 (1H each, both m, H2-7), 1.11 (1H, dd, J )
12.0, 12.0 Hz, HR-2), 1.22 [9H, s, -OCOC(CH3)3], 1.45 (1H, m, H-5),
1.45, 1.59 (1H each, both m, H2-8), 1.69 (1H, ddd, J ) 2.5, 4.3, 12.0
Hz, Hâ-2), 1.93 (1H, m, Hâ-4), 3.76 (1H, m, H-3), 3.79 (1H, m, H-9),
[3.98 (1H, dd, J ) 6.7, 11.3 Hz), 4.15 (1H, dd, J ) 3.4, 11.3 Hz),
H2-10]; 13C NMR (CDCl3, 125 MHz) δ 35.9 (C-1), 50.9 (C-2), 66.8
(C-3), 45.6 (C-4), 33.5 (C-5), 52.6 (C-6), 24.7 (C-7), 35.6 (C-8), 70.7
(C-9), 68.2 (C-10), 20.8 (C-11), 30.6 (C-12), 20.9 (C-13), 178.7
[-OCOC(CH3)3], 38.9 [-OCOC(CH3)3], 27.2 [-OCOC(CH3)3]; EIMS
m/z 314 [M+, (1)], 296 (5), 257 (1), 212 (2), 200 (1), 57 (100); HREIMS
m/z 314.2458 (calcd for C18H34O4 [M+], 314.2457).
1
Compound 2f: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.49
(ddd, J ) 1.8, 4.2, 10.7 Hz, H-6), 0.73, 0.78 (3H each, both s, H3-12,
11), 0.87 (3H, d, J ) 6.4 Hz, H3-13), 0.96 (1H, ddd, J ) 11.9, 11.9,
11.9 Hz, HR-4), 1.01, 1.33 (1H each, both m, H2-7), 1.15, 1.17 [9H
each, both s, -OCOC(CH3)3], 1.15 (1H, dd, J ) 12.1, 12.1 Hz, HR-
2), 1.45 (1H, m, H-5), 1.57, 1.69 (1H each, both m, H2-8), 1.65 (1H,
ddd, J ) 2.5, 4.3, 12.1 Hz, Hâ-2), 1.90 (1H, m, Hâ-4), 3.55 (3H, s,
-COOCH3), [4.08 (1H, dd, J ) 6.7, 12.2 Hz), 4.37 (1H, dd, J ) 3.1,
12.2 Hz), H2-10], 4.81 (1H, m, H-3), 5.23 (1H, m, H-9), 7.34-7.56
(5H, m, Ph-H).
Acid Hydrolysis of 3-8. A solution of 3-8 (each 1.0 mg) in 1 M
HCl (1.0 mL) was heated under reflux for 3 h. After cooling, the
reaction mixture was extracted with EtOAc. The aqueous layer was
subjected to HPLC: column, Kaseisorb LC NH2-60-5, 4.6 mm i.d. ×
250 mm (Tokyo Kasei Co., Ltd., Tokyo, Japan); detection, optical
rotation [Shodex OR-2 (Showa Denko Co., Ltd., Tokyo, Japan); mobile
phase, CH3CN-H2O (85:15, v/v); flow rate 0.8 mL/min]. Identification
of D-glucose present in the aqueous layer was carried out by comparison
of its retention time and optical rotation with those of an authentic
sample.
1
Compound 2b: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.59
(ddd, J ) 2.1, 4.9, 11.0 Hz, H-6), 0.87, 0.95 (3H each, both s, H3-11,
12), 0.95 (3H, d, J ) 6.4 Hz, H3-13), 1.00 (1H, ddd, J ) 12.3, 12.3,
12.3 Hz, HR-4), 1.08, 1.61 (1H each, both m, H2-7), 1.16, 1.22 [9H
each, both s, -OCOC(CH3)3], 1.26 (1H, dd, J ) 12.0, 12.0 Hz, HR-
2), 1.46, 1.59 (1H each, both m, H2-8), 1.52 (1H, m, H-5), 1.67 (1H,
ddd, J ) 2.5, 4.3, 12.0 Hz, Hâ-2), 1.93 (1H, m, Hâ-4), 3.79 (1H, m,
H-9), [3.98 (1H, dd, J ) 6.7, 11.3 Hz), 4.15 (1H, dd, J ) 3.4, 11.3
Hz), H2-10], 4.83 (1H, m, H-3); 13C NMR (CDCl3, 125 MHz) δ 35.9
(C-1), 46.5 (C-2), 69.6 (C-3), 41.1 (C-4), 33.3 (C-5), 52.7 (C-6), 24.6
(C-7), 35.5 (C-8), 70.7 (C-9), 68.2 (C-10), 20.6 (C-11), 30.5 (C-12),
20.7 (C-13), 178.2, 178.8 [-OCOC(CH3)3], 38.6, 38.9 [-OCOC-
(CH3)3], 27.1, 27.2 [-OCOC(CH3)3]; positive-ion CIMS m/z 399 [M
+ 1]+, (9), 381 (3), 297 (100), 279 (14); HRCIMS m/z 399.3106 (calcd
for C23H42O5 [M + 1]+, 399.3110).
Enzymatic Hydrolysis of 3-8 with â-Glucosidase. A solution of
3-6 (3.0, 7.6, 5.0, and 2.0 mg, respectively) in H2O (1.0 mL) was
treated with â-glucosidase (2.0, 2.0, 2.6, 2.0 mg, respectively). The
solution was stirred at 37 °C for 16 h, EtOH was added to the reaction
mixture, the solvent was removed under reduced pressure, and the
residue was purified by HPLC [MeOH-H2O (40:60, v/v)] to furnish
sarmentol A (2, 1.5 mg, 91% from 3; 3.8 mg, 85% from 4; 2.9 mg,
95% from 5) and sarmentol B (6a, 1.0 mg, 85% from 6). A solution of
7 (12.1 mg) or 8 (25.1 mg) in H2O (2.0 mL) was treated with
â-glucosidase (8.0, 18.2 mg, respectively), and the solution was stirred
at 37 °C for 16 h. The residue was purified by HPLC [MeOH-H2O
(40:60, v/v)] to give sarmentols C (7a, 6.3 mg, 89% from 7) and D
(8a, 12.1 mg, 82% from 8), respectively.
Preparation of the (R)-MTPA Esters (2c, 2e) and (S)-MTPA
Esters (2d, 2f) from 2a and 2b. A solution of 2a (7.6 mg) in CH2Cl2
(1.0 mL) was treated with (R)-MTPA (68.3 mg) in the presence of
EDC‚HCl (48.5 mg) and 4-DMAP (21.6 mg), and the mixture was
stirred under reflux for 6 h. Workup of the reaction mixture as described
above gave a residue, which was purified by normal-phase silica gel
CC [800 mg, hexane-EtOAc (40:1 f 10:1 f 5:1 f 2:1, v/v)] to give
2c (1.3 mg, 10%). Using a similar procedure, (S)-MTPA ester derivative
of 2a (2d, 1.2 mg, 10%) was obtained from 2a (7.2 mg) using (S)-
MTPA (62.5 mg), EDC‚HCl (53.4 mg), and 4-DMAP (21.6 mg).
Through the similar procedure, a solution of 2b (4.2 mg) in CH2Cl2
(1.0 mL) was treated with (R)-MTPA (50.7 mg) in the presence of
EDC‚HCl (32.5 mg) and 4-DMAP (17.2 mg), and the mixture was
stirred under reflux for 6 h. Workup of the reaction mixture as described
above gave a residue, which was purified by normal-phase silica gel
CC [580 mg, hexane-EtOAc (20:1 f 10:1, v/v)] to give 2e (0.3 mg,
5%). Using a similar procedure, (S)-MTPA ester derivative of 2b (2f,
0.2 mg, 4%) was obtained from 2b (3.4 mg) using (S)-MTPA (45.8
mg), EDC‚HCl (31.2 mg), and 4-DMAP (15.5 mg).
Sarmentol B (6a): colorless oil; [R]25 +5.6 (c 0.05, MeOH); IR
D
(film) νmax 3372, 2924, 2874, 1474, 1387, 1026, 754 cm-1; H NMR
1
data, see Table 5; 13C NMR data, see Table 6; positive-ion FABMS
m/z 253 [M + Na]+; HRFABMS m/z 253.1771 (calcd for C13H26O3Na
[M + Na]+, 253.1780).
Sarmentol C (7a): colorless oil; [R]23D +11.9 (c 0.22, MeOH); CD
(MeOH) λmax (∆ꢀ) 286 (+0.19); IR (film) νmax 3432, 2955, 2876, 1700,
1653, 1472, 1391, 1285, 1100, 1063 cm-1; 1H NMR data, see Table 5;
13C NMR data, see Table 6; positive-ion CIMS m/z 229 [M + 1]+
(57), 211 (41), 197 (64), 138 (64), 95 (100); HRCIMS m/z 229.1801
(calcd for C13H25O3 [M + 1]+, 229.1804).
Sarmentol D (8a): colorless oil; [R]21 +1.2 (c 0.42, MeOH); IR
D
Compound 2c: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.61
(film) νmax 3346, 2955, 2876, 1717, 1473, 1073, 1026 cm-1; 1H NMR
data, see Table 1; 13C NMR data, see Table 2; EIMS m/z 228 [M]+
(1), 210 (15), 200 (2), 197 (61), 179 (67), 161 (100); HREIMS: m/z
228.1723 (calcd for C13H24O3, 228.1725).
1
(ddd, J ) 2.5, 4.6, 11.1 Hz, H-6), 0.89, 0.95 (3H each, both s, H3-12,
11), 0.98 (3H, d, J ) 6.7 Hz, H3-13), 1.09, 1.60 (1H each, both m,
H2-7), 1.17 (1H, ddd, J ) 12.2, 12.2, 12.2 Hz, HR-4), 1.22 [9H, s,
-OCOC(CH3)3], 1.25 (1H, dd, J ) 12.2, 12.2 Hz, HR-2), 1.45, 1.59
(1H each, both m, H2-8), 1.55 (1H, m, H-5), 1.73 (1H, ddd, J ) 2.5,
4.3, 12.2 Hz, Hâ-2), 2.05 (1H, m, Hâ-4), 3.56 (3H, s, -COOCH3),
3.78 (1H, m, H-9), [3.98 (1H, dd, J ) 6.7, 11.3 Hz), 4.14 (1H, dd, J
) 3.4, 11.3 Hz), H2-10], 5.14 (1H, m, H-3), 7.39-7.53 (5H, m, Ph-
H).
NaBH4 Reduction of 7 and 8. A solution of 7 (5.1 mg) in MeOH
(1.5 mL) was treated with NaBH4 (1.2 mg), and the mixture was stirred
at room temperature for 30 min. The reaction mixture was quenched
in acetone, and then removal of the solvent under reduced pressure
gave a residue, which was purified by HPLC [MeOH-H2O (34:66,
v/v)] to give 5 (0.7 mg, 14%) and 7b (0.2 mg, 4%). Through the similar
procedure, a solution of 8 (20.0 mg) in MeOH (2.0 mL) was treated
with NaBH4 (3.0 mg) and the mixture was stirred at room temperature
for 30 min. Workup of the reaction mixture as described above gave
a residue, which was purified by HPLC [MeOH-H2O (25:75, v/v)] to
give 5 (6.3 mg, 31%) and 8d (6.3 mg, 31%).
1
Compound 2d: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.60
(ddd, J ) 2.5, 4.6, 11.1 Hz, H-6), 0.90, 0.98 (3H each, both s, H3-12,
11), 0.96 (3H, d, J ) 6.5 Hz, H3-13), 1.07 (1H, ddd, J ) 12.3, 12.3,
12.3 Hz, HR-4), 1.09, 1.60 (1H each, both m, H2-7), 1.22 [9H, s,
-OCOC(CH3)3], 1.35 (1H, dd, J ) 11.9, 11.9 Hz, HR-2), 1.45, 1.58
(1H each, both m, H2-8), 1.53 (1H, m, H-5), 1.79 (1H, ddd, J ) 2.5,
4.3, 11.9 Hz, Hâ-2), 1.98 (1H, m, Hâ-4), 3.55 (3H, s, -COOCH3),
3.78 (1H, m, H-9), [3.97 (1H, dd, J ) 6.7, 11.3 Hz), 4.14 (1H, dd, J
) 3.4, 11.3 Hz), H2-10], 5.14 (1H, m, H-3), 7.40-7.53 (5H, m, Ph-
H).
1
Compound 7b: H NMR (CD3OD, 500 MHz) δ 0.53 (1H, ddd, J
) 2.1, 5.0, 11.0 Hz, H-6), 0.83, 0.95 (3H each, both s, H3-12, 11),
0.98 (3H, d, J ) 6.2 Hz, H3-13), 1.60 (1H, m, H-5), [3.52 (1H, dd, J
) 5.5, 11.2 Hz), 3.68 (1H, dd, J ) 3.1, 11.2 Hz), H2-10], [3.64 (1H,
m), 3.86 (1H, dd, J ) 1.6, 10.1 Hz), H2-6′], 3.96 (1H, m, H-3), 4.41
(1H, d, J ) 7.6 Hz, H-1′); positive-ion FABMS m/z 415 [M + Na]+;
HRFABMS m/z 415.2316 (calcd for C19H36O8Na [M + Na]+, 415.2308).
Compound 8d: amorphous powder; [R]25D -20.2 (c 2.50, MeOH);
IR (KBr) νmax 3422, 2940, 1565, 1475, 1078 cm-1; 1H NMR data, see
1
Compound 2e: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.56
(ddd, J ) 2.1, 4.9, 11.0 Hz, H-6), 0.81, 0.88 (3H each, both s, H3-12,
11), 0.92 (3H, d, J ) 6.4 Hz, H3-13), 0.99 (1H, ddd, J ) 12.0, 12.0,
12.0 Hz, HR-4), 1.10, 1.49 (1H each, both m, H2-7), 1.14, 1.16 [9H

Megastigmanes from Sedum sarmentosum
Journal of Natural Products, 2007, Vol. 70, No. 4 583
Table 5; 13C NMR data, see Table 6; positive-ion FABMS m/z 415 [M
+ Na]+; HRFABMS m/z 415.2301 (calcd for C19H36O8Na [M + Na]+,
415.2308).
Enzymatic Hydrolysis of 8d with â-Glucosidase. A solution of
8d (5.0 mg) in H2O (1.0 mL) was treated with â-glucosidase (3.0 mg),
and the solution was stirred at 37 °C for 16 h. After EtOH was added
to the reaction mixture, the solvent was removed under reduced pressure
and the residue was purified by HPLC [MeOH-H2O (40:60, v/v)] to
give 6a (2.7 mg, 92%).
(4) He, A.; Wang, M. Zhongcaoyao 1997, 28, 517-522.
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Daxue Xuebao 2003, 26, 59-61.
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Preparation of the (R)-MTPA Ester (8b) and (S)-MTPA Ester
(8c) from 8a. A solution of 8a (6.4 mg) in CH2Cl2 (1.0 mL) was treated
with (R)-MTPA (78.6 mg) in the presence of EDC‚HCl (62.1 mg) and
4-DMAP (30.5 mg), and the mixture was stirred at room temperature
for 6 h. Workup of the reaction mixture as described above gave a
residue, which was purified by normal-phase silica gel CC [1.0 g,
hexane-EtOAc (30:1 f 10:1, v/v)] to give 8b (10.4 mg, 61%). Using
a similar procedure, the (S)-MTPA ester 8c (8.3 mg, 62%) was obtained
from 8a (4.7 mg) using (S)-MTPA (78.5 mg), EDC‚HCl (60.1 mg),
and 4-DMAP (23.9 mg).
(10) Fang, S.; Yan, X.; Li, J.; Fan, Z.; Xu, X.; Xu, R. Huaxue Xuebao
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M. J. Nat. Prod. 2002, 65, 1468-1474.
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2003, 66, 638-645.
1
Compound 8b: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.60
(ddd, J ) 2.8, 5.5, 11.0 Hz, H-6), 0.89, 0.93 (3H each, both s, H3-11,
12), 0.96 (3H, d, J ) 6.4 Hz, H3-13), 1.17 (1H, ddd, J ) 11.9, 11.9,
11.9 Hz, HR-4), 1.25 (1H, dd, J ) 12.5, 12.5 Hz, HR-2), 1.42, 1.77
(1H each, both m, H2-7), 1.57 (1H, m, H-5), 1.73 (1H, ddd, J ) 2.8,
4.6, 12.5 Hz, Hâ-2), 2.05 (1H, m, Hâ-4), [2.40 (1H, ddd, J ) 5.8,
11.0, 17.4 Hz), 2.52 (1H, ddd, J ) 4.9, 11.6, 17.4 Hz), H2-8], 3.54,
3.64 (3H each, both s, -COOCH3), 4.78, 4.89 (1H each, both d, J )
16.5 Hz, H2-10), 5.13 (1H, m, H-3), 7.39-7.64 (10H, m, Ph-H).
(16) Tao, J.; Morikawa, T.; Ando, S.; Matsuda, H.; Yoshikawa, M. Chem.
Pharm. Bull. 2003, 51, 654-662.
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2004, 70, 847-855.
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S.; Yoshikawa, M. J. Nat. Prod. 2004, 67, 1464-1469.
(19) Morikawa, T.; Sun, B.; Matsuda, H.; Wu, L. J.; Harima, S.;
Yoshikawa, M. Chem. Pharm. Bull. 2004, 52, 1194-1199.
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1
Compound 8c: colorless oil; H NMR (CDCl3, 500 MHz) δ 0.60
(ddd, J ) 2.5, 5.2, 10.7 Hz, H-6), 0.90, 0.96 (3H each, both s, H3-11,
12), 0.93 (3H, d, J ) 6.4 Hz, H3-13), 1.07 (1H, ddd, J ) 11.9, 11.9,
11.9 Hz, HR-4), 1.34 (1H, dd, J ) 12.2, 12.2 Hz, HR-2), 1.40, 1.76
(1H each, both m, H2-7), 1.55 (1H, m, H-5), 1.80 (1H, ddd, J ) 2.2,
4.3, 12.2 Hz, Hâ-2), 1.97 (1H, m, Hâ-4), [2.40 (1H, ddd, J ) 6.1,
10.4, 16.8 Hz), 2.51 (1H, ddd, J ) 5.2, 11.0, 16.8 Hz), H2-8], 3.54,
3.64 (3H each, both s, -COOCH3), 4.78, 4.89 (1H each, both d, J )
16.5 Hz, H2-10), 5.13 (1H, m, H-3), 7.39-7.64 (10H, m, Ph-H).
(23) Xie, H.; Morikawa, T.; Matsuda, H.; Nakamura, S.; Muraoka, O.;
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Acknowledgment. Part of this work was supported by the 21st COE
program and Academic Frontier Project from the Ministry of Education,
Culture, Sports, Science and Technology of Japan.
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52, 445-450.
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Supporting Information Available: 1H-1H COSY, HMBC, and
NOE correlations of 1-8 (Figure S1). This information is available
free of charge via the Internet at http://pubs.acs.org.
(29) Otsuka, H.; Tamaki, A. Chem. Pharm. Bull. 2002, 50, 390-394.
1
(30) The H and 13C NMR spectra of 1-8, 1a, 1f, 6a-8a, and 8d were
assigned with the aid of distortionless enhancement by polarization
transfer (DEPT), homocorrelation spectroscopy (1H-1H COSY),
heteronuclear multiple quantum coherence (HMQC), and HMBC
experiments.
References and Notes
(1) This paper is number 21 in our series Bioactive Constituents from
Chinese Natural Medicines. For paper number 20, see: Matsuda,
H.; Sugimoto, S.; Morikawa, T.; Kubo, M.; Nakamura, S.; Yoshika-
wa, M. Chem. Pharm. Bull. 2007, 55, 106-110.
(2) Shanghai Scientific and Technologic Press Ed. Dictionary of Chinese
Traditional Medicines; Shogakkan: Tokyo, 1985; pp 1427-1428.
(3) Kang, T. H.; Pae, H. O.; Yoo, J. C.; Kim, N. Y.; Kim, Y. C.; Ko, G.
I.; Chung, H. T. J. Ethnopharmacol. 2000, 70, 177-182.
(31) Ohtani, I.; Kusumi, T.; Kashman, Y.; Kakisawa, H. J. Am. Chem.
Soc. 1991, 113, 4092-4096.
(32) Inada, A.; Nakamura, Y.; Konishi, M.; Murata, H.; Kitamura, F.;
Toya, H.; Nakanishi, T. Chem. Pharm. Bull. 1991, 39, 2437-2439.
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