Acylated-oxypregnane glycosides from the roots of asclepias syriaca

Article abstract of DOI:10.1248/cpb.57.177

Twenty new pregnane glycosides were obtained from the roots of Asclepias syriaca L. (Asclepiadaceae). These glycosides were confirmed to contain ikemagenin, 12-0-nicotinoyllineolon, 5α,6-dihydroikemagenin, and 12-O-tigloylisolineolon, as their aglycones,

Full text of DOI:10.1248/cpb.57.177

February 2009
Chem. Pharm. Bull. 57(2) 177—184 (2009)
177
Acylated-Oxypregnane Glycosides from the Roots of Asclepias syriaca
Tsutomu WARASHINA* and Tadataka NORO
Institute for Environmental Sciences, University of Shizuoka; 52–1 Yada, Suruga-ku, Shizuoka 422–8526, Japan.
Received October 29, 2008; accepted November 25, 2008; published online November 26, 2008
Twenty new pregnane glycosides were obtained from the roots of Asclepias syriaca L. (Asclepiadaceae).
These glycosides were confirmed to contain ikemagenin, 12-O-nicotinoyllineolon, 5a,6-dihydroikemagenin, and
12-O-tigloylisolineolon, as their aglycones, using both spectroscopic and chemical methods.
Key words Asclepias syriaca L.; Asclepiadaceae; syriacoside; acylated-oxypregnane glycoside; 2,6-dideoxyhexopyranose
Asclepias syriaca L. is a plant indigenous to North Amer- Thus, 1 was glycosylated at the C-3 position, and was con-
ica and distributed widely. The monarch butterfly (Danaus sidered to be ikemagenin 3-O-diglycoside. Moreover, acid
plexippus L.) feeds on the Asclepias genus for protection hydrolysis of 1 showed that the sugar moiety consisted of
from vertebrate predators.1) Asclepias species are known to digitoxose and oleandrose, and these sugars were identified
contain many kinds of cardenolides and their glycosides.2—9) as b-D-digitoxopyranose and b-D-oleandropyranose, as
A. syriaca has also been reported to contain these com- judged from the J values of each anomeric proton signal
pounds.10—12) We have previously studied cardenolides and (Jꢂ9.5, 2.5 Hz). The sequence of the sugar moiety was deter-
their glycosides.13) But, until now, there have been no reports mined from measurements of the rotating frame nuclear
about pregnane glycosides from A. syriaca. Pregnane glyco- Overhauser effect (ROE) difference spectra irradiating at the
sides are considered characteristic of Asclepias species.14—18) anomeric proton of each sugar in 1. ROEs were found be-
Accordingly, we started an investigation of pregnane glyco- tween d 5.50 (H-1ꢃ of b-D-digitoxopyranose) and 3.89 (H-3
sides and found twenty new 12-O-acylated-oxypregnane gly- of the aglycone), and d 4.81 (H-1ꢄ of b-D-oleandropyranose)
cosides in the roots of A. syriaca. The present paper de- and 3.56 (H-4ꢃ of b-D-digitoxopyranose). Thus, 1 was estab-
scribes the isolation and structural determination of these lished to be ikemagenin 3-O-b-D-oleandropyranosyl-(1→4)-
new pregnane glycosides.
A MeOH extract from the dried roots of A. syriaca was
b-D-digitoxopyranoside, and named syriacoside A.
The compounds 2—6, 8, 9, 11, 14—17, 19—22, 24, 25,
suspended in water. The suspension was extracted with di- and 26 were also glycosylated at the C-3 position of each
ethyl ether and partitioned into an ether-soluble fraction, a aglycone, based on observations of glycosylation shifts in the
water-soluble fraction and an ether–water emulsified fraction. 13C-NMR spectra.
The residues of these fractions were chromatographed on a
HR-FAB-MS showed the molecular formula of 2 to be
silica gel column to give fractions of acylated-oxypregnane C50H72O15, suggesting that it was larger by one hexose unit
1
glycosides from which twenty new compounds were ob- than 1. Because the H- and 13C-NMR spectra of 2 showed
tained along with seven known compounds. The structural three anomeric proton and carbon signals at d 5.47, 5.18, and
determination of the known compounds 7, 10, 12, 13, 18, 23, 4.76 and d 96.4, 99.7, and 102.2, respectively, along with
and 27 was made based on comparisons of NMR spectral signals due to 1a, 2 was indicated to be ikemagenin 3-O-
data with data in the literature.16,17,19)
triglycoside. Acid hydrolysis of 2 afforded digitoxose, cy-
In order to acquire the component aglycones and sugars, marose, and oleandrose with 1a. Thus, the sugar moiety of 2
the fraction containing pregnane glycosides from the silica consisted of one b-D-digitoxopyranose, one b-D-cymaropyra-
1
gel column chromatography was subjected to acid hydroly- nose, and one b-D-oleandropyranose. In the H-NMR spec-
sis. The afforded aglycones were identified as ikemage- trum, the characteristic H-3 signals of b-D-digitoxopyranose
nin (1a),19,20) 5a,6-dihydroikemagenin (20a),17) and 12-O- and b-D-cymaropyranose were observed at d 4.64 (1H, br s)
1
tigloylisolineolon (21a),17) in view of the H- and 13C-NMR and 4.06 (1H, q, Jꢂ3.0 Hz), respectively. In consideration of
1
spectral data.
the result of H–1H shift correlation spectroscopy (COSY)
The acquired sugar mixtures were fractionated to cy- experiment, the signals at d 5.47 and 5.18 were assigned to
marose, oleandrose, digitoxose, and canarose using silica gel the anomeric protons of b-D-digitoxopyranose and b-D-cy-
column chromatography. The absolute configurations of maropyranose, and the remaining signal at d 4.76 was as-
these sugars were believed to be D-forms on the basis of the signed to the anomeric proton of b-D-oleandropyranose. The
optical rotation values.
ROE difference spectra irradiating at the anomeric protons
Compound 1 was suggested to have the molecular formula exhibited ROEs between d 5.47 (H-1ꢃ of b-D-digitoxopyra-
C47H70O16 based on high resolution (HR)-FAB-MS [m/z: nose) and 3.87 (H-3 of the aglycone), d 5.18 (H-1ꢄ of b-D-
1
791.3992 [MꢀNa]ꢀ]. In the H- and 13C-NMR spectra of 1, cymaropyranose) and 3.51 (H-4ꢃ of b-D-digitoxopyranose),
two anomeric proton and carbon signals were observed at d and d 4.76 (H-1ꢅ of b-D-oleandropyranose) and 3.45 (H-4ꢄ
5.50, 4.81 and d 96.4, 101.6, in addition to signals due to the of b-D-cymaropyranose). On comparison of the 13C-NMR
aglycone, which was identified as 1a by acid hydrolysis with spectral data of the sugar moiety of 2 with those of 1, the sig-
0.1 M H2SO4. The 13C-NMR spectral comparison of 1 with 1a nals due to the terminal b-D-oleandropyranosyl group were
showed glycosylation shifts at the C-2, C-3 and C-4 positions observed. Therefore, 2 was determined as ikemagenin 3-O-
[C-2 (ꢁ2.2 ppm), C-3 (ꢀ6.1 ppm), C-4 (ꢁ4.1 ppm)].21) b-D-oleandropyranosyl-(1→4)-b-D-cymaropyranosyl-(1→4)-
∗ To whom correspondence should be addressed. e-mail: warashin@u-shizuoka-ken.ac.jp
© 2009 Pharmaceutical Society of Japan

178
Vol. 57, No. 2
b-D-digitoxopyranoside, and named syriacoside B.
was considered to be ikemagenin 3-O-tetraglycoside. The
The molecular formula of both 3 and 4 was C50H72O15 NMR spectral data of the sugar moiety in 8 were consistent
from measurements of HR-FAB-MS, the same as 2. The H- with those of cynanchoside D2,22) so 8 was proposed to pos-
1
and 13C-NMR data suggested these compounds to be ikema- sess the same sugar sequence as cynanchoside D2. Hence, 8
genin 3-O-triglycosides. Acid hydrolysis yielded digitoxose, was elucidated to be ikemagenin 3-O-b-D-glucopyranosyl-
oleandrose, and cymarose from 3, and digitoxose and cy- (1→4)-b-D-oleandropyranosyl-(1→4)-b-D-cymaropyranosyl-
marose from 4 together with 1a. Comparison of the 13C- (1→4)-b-D-cymaropyranoside, and named syriacoside G.
18)
NMR spectral data for 3 with those for curassavioside I1
HR-FAB-MS showed the molecular formula of compound
and 1 revealed the presence of a terminal b-D-cymaropyra- 9 to be C56H82O18, which was smaller by CH2 than 10. The
nose and glycosylation shifts around the C-4ꢄ position of 1H- and 13C-NMR spectra revealed that 9 was also ikema-
the b-D-oleandropyranosyl group [C-3ꢄ (ꢁ2.4 ppm), C-4ꢄ genin 3-O-tetraglycoside. On acid hydrolysis, 9 afforded dig-
(ꢀ6.5 ppm), C-5ꢄ (ꢁ1.2 ppm)]. Thus, the sugar sequence of itoxose, cymarose and oleandrose together with 1a, and two
3 was indicated to be 3-O-b-D-cymaropyranosyl-(1→4)-b- methoxyl proton signals were observed at d 3.58 and 3.47 in
D-oleandropyranosyl-(1→4)-b-D-digitoxopyranoside, which the 1H-NMR spectrum. Thus, the sugar moiety of 9 consisted
was confirmed in the ROE difference experiment irradiating of two b-D-digitoxopyranoses, one b-D-cymaropyranose, and
1
each anomeric proton. Namely, ROEs were observed be- one b-D-oleandropyranose. Comparison of the H- and 13C-
tween d 4.93 (H-1ꢃ of b-D-digitoxopyranose) and 3.57 (H-3 NMR spectral data of 9 with those of 10 and 2 suggested the
of the aglycone), d 4.50 (H-1ꢄ of b-D-oleandropyranose) and sugar sequence to be 3-O-b-D-oleandropyranosyl-(1→4)-b-
3.20 (H-4ꢃ of b-D-digitoxopyranose), and d 4.87 (H-1ꢅ of D-cymaropyranosyl-(1→4)-b-D-digitoxopyranosyl-(1→4)-b-
b-D-cymaropyranose) and 3.16 (H-4ꢄ of b-D-oleandropyra- D-digitoxopyranoside, which was confirmed by the ROE dif-
nose). From the observation of two signals due to the ference experiment. ROEs were observed between d 5.46 (H-
methoxyl group (d 3.62, 3.46) in the 1H-NMR spectrum of 4 1ꢃ of b-D-digitoxopyranose) and 3.87 (H-3 of the aglycone),
and the result of acid hydrolysis, the sugar moiety of 4 was d 5.37 (H-1ꢄ of b-D-digitoxopyranose) and 3.57 (H-4ꢃ of b-
composed of one b-D-digitoxopyranose and two b-D-cy- D-digitoxopyranose), d 5.15 (H-1ꢅ of b-D-cymaropyranose)
maropyranoses. ROEs were observed between d 5.27 (H-1ꢃ and 3.44 (H-4ꢄ of b-D-digitoxopyranose) and d 4.76 (H-1ꢄꢄ
of b-D-cymaropyranose) and 3.85 (H-3 of the aglycone), d of b-D-oleandropyranose) and 3.46 (H-4ꢅ of b-D-cymaropy-
5.32 (H-1ꢄ of b-D-digitoxopyranose) and 3.53 (H-4ꢃ of b-D- ranose). Thus, 9 was identified as shown in Chart 1, and
cymaropyranose), and d 5.12 (H-1ꢅ of b-D-cymaropyranose) named syriacoside H.
and 3.46 (H-4ꢄ of b-D-digitoxopyranose). Thus, the sugar se-
The molecular formula of compound 11 was suggested to
1
quence of 4 was established to be 3-O-b-D-cymaropyranosyl- be C57H84O18 based on HR-FAB-MS. The H- and 13C-NMR
(1→4)-b-D-digitoxopyranosyl-(1→4)-b-D-cymaropyra- spectra of 11 were similar to those of 10, but with a terminal
noside. 3 and 4 are shown in Chart 1, and were named syria- b-D-cymaropyranosyl group instead of the b-D-oleandropyra-
coside C and D, respectively.
nosyl group. Thus, the sugar sequence of 11 was presumed to
HR-FAB-MS showed the molecular formula of com- be 3-O-b-D-cymaropyranosyl-(1→4)-b-D-cymaropyranosyl-
pounds 5 and 6 to be C50H72O15 and C51H74O15, respectively. (1→4)-b-D-digitoxopyranosyl-(1→4)-b-D-cymaropyra-
The 1H- and 13C-NMR data suggested these compounds were noside. ROEs were revealed between d 5.27 (H-1ꢃ of b-D-cy-
also ikemagenin 3-O-triglycosides. Acid hydrolysis yielded maropyranose) and 3.84 (H-3 of the aglycone), d 5.31 (H-1ꢄ
canarose and oleandrose from 5, and oleandrose from 6, to- of b-D-digitoxopyranose) and 3.52 (H-4ꢃ of b-D-cymaropyra-
gether with 1a. The sugar moieties consisted of one b-D-ca- nose), d 5.15 (H-1ꢅ of b-D-cymaropyranose) and 3.45 (H-4ꢄ
naropyranose and two b-D-oleandropyranoses in 5, and three of b-D-digitoxopyranose) and d 5.07 (H-1ꢄꢄ of b-D-cymaro-
b-D-oleandropyranoses in 6. The assignment of the signals pyranose) and 3.43 (H-4ꢅ of b-D-cymaropyranose). These
due to the sugar moieties was carried out based on the results results supported the above sugar sequence. This compound
of COSY and homonuclear Hartmann-Hahn (HOHAHA) ex- was named syriacoside I.
periments irradiating each anomeric proton, and sugar se-
HR-FAB-MS revealed the molecular formula of com-
quences were determined based on the observations of pound 14 to be C55H83NO18. Based on acid hydrolysis, and
ROEs. ROEs were observed between d 4.59 (H-1ꢃ of b-D-ca- the 1H- and 13C-NMR spectral data, this compound was iden-
naropyranose) and 3.57 (H-3 of the aglycone), d 4.45 (H-1ꢄ tified as 12-O-nicitinoyllineolon 3-O-b-D-cymaropyranosyl-
of b-D-oleandropyranose) and 2.96 (H-4ꢃ of b-D-canaropyra- (1→4)-b-D-oleandropyranosyl-(1→4)-b-D-cymaropyranosyl-
nose), and d 4.70 (H-1ꢅ of b-D-oleandropyranose) and 3.22 (1→4)-b-D-cymaropyranoside, a sugar sequence reported
(H-4ꢄ of b-D-oleandropyranose) in 5, and d 4.53 (H-1ꢃ of b- previously.16,19) This compound was named syriacoside J.
D-oleandropyranose) and 3.56 (H-3 of the aglycone), d 4.67
The molecular formula of both 15 and 16 was shown to be
(H-1ꢄ of b-D-oleandropyranose) and 3.17 (H-4ꢃ of b-D-olean- C58H86O18 based on HR-FAB-MS. Acid hydrolysis, and the
dropyranose), and d 4.72 (H-1ꢅ of b-D-oleandropyranose) 1H- and 13C-NMR spectra revealed these compounds to also
and 3.18 (H-4ꢄ of b-D-oleandropyranose) in 6. Thus, com- be ikemagenin 3-O-tetraglycosides, their sugar sequences
pounds 5 and 6 were identified as shown in Chart 1, and composed of two b-D-cymaropyranoses and two b-D-olean-
named syriacoside E and F, respectively.
dropyranoses. In the ROE difference experiment, ROEs were
The molecular formula of compound 8 was suggested to observed between d 4.85 (H-1ꢃ of b-D-cymaropyranose) and
be C57H84O20 based on HR-FAB-MS. On the basis of obser- 3.56 (H-3 of the aglycone), d 4.44 (H-1ꢄ of b-D-oleandropy-
vation of four anomeric proton and carbon signals at d 5.28, ranose) and 3.22 (H-4ꢃ of b-D-cymaropyranose), d 4.95 (H-
5.12ꢆ2, and 4.69 and at d 96.5, 100.5, 101.9, and 104.5 with 1ꢅ of b-D-cymaropyranose) and 3.18 (H-4ꢄ of b-D-olean-
the signals due to 1a, in the 1H- and 13C-NMR spectra of 8, 8 dropyranose), and d 4.50 (H-1ꢄꢄ of b-D-oleandropyranose)

February 2009
179
Chart 1. Structures of Compounds 1—27
and 3.24 (H-4ꢅ of b-D-cymaropyranose). Thus, 15 was iden- sis of 17 afforded 9, and a glycosylation shift was observed
tified as ikemagenin 3-O-b-D-oleandropyranosyl-(1→4)-b-D- around the C-4ꢄꢄ position of b-D-oleandropyranose on com-
cymaropyranosyl-(1→4)-b-D-oleandropyranosyl-(1→4)-b-D- parison of the 13C-NMR spectral data of 17 with those of 9
cymaropyranoside. The 1H- and 13C-NMR spectra of 16 [C-3ꢄꢄ (ꢁ2.1 ppm), C-4ꢄꢄ (ꢀ6.8 ppm), C-5ꢄꢄ (ꢁ0.9 ppm)].
showed the presence of a terminal b-D-cymaropyranosyl Therefore, this terminal b-D-glucopyranosyl group was at-
group in its sugar sequence, and glycosylation shifts tached at the C-4ꢄꢄ position of b-D-oleandropyranose, and the
around the C-4ꢅ position of b-D-oleandropyranose [C-3ꢅ ROE difference experiment irradiating the anomeric proton
(ꢁ1.7 ppm), C-4ꢅ (ꢀ6.9 ppm), C-5ꢅ (ꢁ0.7 ppm)] in compar- of this b-D-glucopyranosyl group supported this linkage.
ison with cynanchogenin 3-O-b-D-oleandropyranosyl-(1→4)- From the above results, 17 was determined as shown in Chart
b-D-oleandropyranosyl-(1→4)-b-D-cymaropyranoside.19) 1, and named syriacoside M.
Thus, the structure of 16 was elucidated to be ikemagenin 3-
HR-FAB-MS revealed the molecular formula of com-
O-b-D-cymaropyranosyl-(1→4)-b-D-oleandropyranosyl- pounds 19—21 to be C63H94O23, C63H96O23, and C59H94O23,
(1→4)-b-D-oleandropyranosyl-(1→4)-b-D-cymaropyra- respectively. Based on the 1H- and 13C-NMR spectral data for
noside, which was confirmed by the ROE difference experi- the sugar moieties of 19—21, these compounds were consid-
ment irradiating each anomeric proton signal. These com- ered to have the same sugar sequences, which included a ter-
pounds were named syriacoside K and L, respectively.
minal b-D-glucopyranosyl group. The aglycone moieties of
1
The H- and 13C-NMR spectra of 17 showed the presence 19—21 were suggested to be 1a, 20a, and 21a, according to
of a terminal b-D-glucopyranosyl group. Enzymatic hydroly- their 13C-NMR spectral data and acid hydrolysis. On the

180
Vol. 57, No. 2
basis of the production of 11 from 19 by enzymatic hydroly- osil-C8 20 mm i.d.ꢆ25 cm and YMC-ODS 20 mm i.d.ꢆ25 cm: 51—67.5%
MeCN in water and 75—82.5% MeOH in water), fractions B (2.15 g) and D
(2.21 g) afforded compounds 1 (6 mg), 2 (13 mg), 3 (4 mg), 4 (11 mg), 5
(6 mg), 6 (6 mg), 7 (11 mg), 9 (10 mg), 10 (8 mg), 11 (8 mg), 12 (36 mg), 13
(15 mg), 14 (6 mg), 15 (6 mg), 16 (6 mg), 17 (7 mg), 18 (8 mg), 19 (21 mg),
sis, observation of the glycosylation shifts around the C-4ꢄꢄ
position of b-D-cymaropyranose on comparison of the 13C-
NMR spectral data of 19 with those of 11 [C-3ꢄꢄ (ꢁ0.8 ppm),
C-4ꢄꢄ (ꢀ8.9 ppm), C-5ꢄꢄ (ꢁ1.6 ppm)], and observation of
an ROE between the anomeric proton of the terminal b-D-
glucopyranosyl group [d 4.93 (1H, d, Jꢂ8.0 Hz)] and H-4ꢄꢄ
of b-D-cymaropyranosyl group [d 3.65 (1H, dd, Jꢂ9.5,
3.0 Hz)], the structure of 19 was determined as shown in
Chart 1. Compounds 20 and 21 are also described in Chart 1.
Compounds 19—21 were named syriacoside N, O, and P, re-
spectively.
The molecular formula of compound 22 was considered to
be C63H94O23 based on HR-FAB-MS. Compound 22e ob-
tained from 22 by enzymatic hydrolysis was found to be
identical to ikemagenin 3-O-b-D-oleandropyranosyl-(1→4)-
b-D-cymaropyranosyl-(1→4)-b-D-digitoxopyranosyl-(1→4)-
b-D-cymaropyranoside17) by HPLC with an authentic sample.
The observation of an ROE between d 5.11 (H-1ꢄꢅ of the ter-
20 (6 mg), 21 (11 mg), 22 (6 mg), 23 (6 mg), 24 (3 mg), 25 (18 mg), 26
(6 mg), and 27 (6 mg). The water-soluble fraction of the MeOH extract was
passed through a porous polymer gel (Mitsubishi Diaion HP-20) column and
the absorbed material was eluted with MeOH–H2O (1 : 1), MeOH–H2O
(7 : 3) and MeOH, respectively. The MeOH fraction from the column was
then evaporated dry, and the residue (13.9 g) was subjected to silica gel CC
with a CHCl3–MeOH (98 : 2—8 : 2) system to obtain five fractions (Aꢃ
(2.45 g), Bꢃ (3.05 g), Cꢃ (2.32 g), Dꢃ (3.57 g) and Eꢃ (1.24 g)). Using semi-
preparative HPLC (Develosil-ODS-15/30 50 mm i.d.ꢆ100 cm, Develosil-
PhA 20 mm i.d.ꢆ25 cm, and YMC-ODS 20 mm i.d.ꢆ25 cm: 45—55%
MeCN in water and 80% MeOH in water), fraction Bꢃ (2.15 g) afforded
compounds 8 (4 mg), 17 (21 mg), 18 (9 mg), 19 (12 mg), 22 (7 mg), and 26
(8 mg).
Syriacoside A (1): Amorphous powder. [a]D22 ꢁ5.0° (cꢂ0.62, MeOH).
UV lMmaexOH nm (log e): 217 (4.18), 222 (4.12), 278 (4.35). FAB-MS m/z: 791
[MꢀNa]ꢀ. HR-FAB-MS m/z: 791.3992 (Calcd for C43H60O12Na: 791.3982).
13C-NMR: shown in Tables 1 and 2. 1H-NMR data of the aglycone and ester
moieties (pyridine-d5 at 35 °C) d: 7.98 (1H, d, 16.0, H-3e), 7.62 and 7.34
minal b-D-glucopyranose) and d 3.71 (H-4ꢄꢄ of b-D-olean- (5H, m, H-5e—9e), 6.78 (1H, d, 16.0, H-2e), 5.30 (1H, br s, H-6), 5.26 (1H,
dropyranose), and glycosylation shifts around the C-4ꢄꢄ posi-
dd, 11.5, 4.0, H-12), 3.89 (1H, m, H-3), 2.28 (3H, s, H-21), 2.01 (3H, s, H-
1
18), 1.35 (3H, s, H-19). H-NMR data of the sugar moiety (pyridine-d5 at
tion of b-D-oleandropyranosyl group [C-3ꢄꢄ (ꢁ2.0 ppm), C-
35 °C) d: 5.50 (1H, dd, 9.5, 2.5, H-1ꢃ), 4.81 (1H, dd, 9.5, 2.5, H-1ꢄ), 4.67
4ꢄꢄ (ꢀ6.8 ppm), C-5ꢄꢄ (ꢁ0.9 ppm)] revealed the terminal b-
(1H, br s, H-3ꢃ), 4.34 (1H, dq, 9.5, 6.0, H-5ꢃ), 3.59 (1H, dq, 9.0, 6.0, H-5ꢄ),
D-glucopyranosyl group to be linked at C-4ꢄꢄ of b-D-olean-
3.56 (1H, dd, 9.5, 3.0, H-4ꢃ), 3.46 (3H, s, C-3-OMe), 1.51 (6H, d, 6.0, H-6ꢃ,
H-6ꢄ).
dropyranose, the same as 17. Thus, 22 was identified as
Syriacoside B (2): Amorphous powder. [a]D22 ꢀ6.1° (cꢂ1.09, MeOH).
shown in Chart 1, and named syriacoside Q.
Compounds 24—26 were elucidated to have the molecular
UV lMmaexOH nm (log e): 217 (4.16), 222 (4.09), 278 (4.33). FAB-MS m/z: 935
formula C64H96O23, C64H96O23, and C60H96O23, respectively,
based on HR-FAB-MS. The 1H- and 13C-NMR spectra
showed the aglycone moieties to be 1a on 24 and 25, and 21a
on 26. The sugar moieties of 24—26 were identified as
shown in Chart 1, according to the consistency of the 1H- and
13C-NMR spectral data of these compounds with those of
previously reported ones.14,23) Thus, 24—26 were identified
as described in Chart 1, and named syriacoside R, S, and T,
respectively.
Table 1. 13C-NMR Data for the Aglycone and Ester Moieties of Com-
pounds 1, 14, 20, and 21
Carbon No.
1
14
20
21
Aglycone moieties
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
39.0
29.9
77.7
39.3
139.5
119.2a)
35.2
74.6
44.8
37.6
25.0
73.4
55.9
87.5
34.2
22.6
60.6
15.8
18.2
209.3
32.2
39.0
29.9
77.7
39.3
139.5
119.2
35.2
74.5
44.7
37.6
25.0
74.3
56.1
87.5
34.2
22.2
60.2
15.8
18.2
209.8
32.4
38.1
29.6
76.7
35.0
45.4
25.2
34.6
76.5
47.5
36.6
24.0
73.9
56.3
87.5
33.9
22.4
60.4
16.2
13.1
209.4
32.3
39.0
29.9
77.7a)
39.3
A. syriaca has been found to contain many kinds of acy-
lated-oxypregnane glycosides along with cardenolide glyco-
sides. Recently, it was reported that a 12-tigloyl pregnane
glycoside named P57AS3 from Hoodia gordonii in Asclepi-
adaceous plants acts as an appetite suppressant.24) Because
similar oxypregnane glycosides have been discovered in this
plant, we are interested in not only the toxicity of cardenolide
glycosides, but also the biological activities including the ap-
petite-suppressing effects of these 12-tigloyl oxypregnane
glycosides.
139.2
119.4
35.9
74.3
45.1
37.6
24.7b)
77.6a)
55.0
86.6
36.7
24.6b)
59.2
17
18
19
20
Experimental
12.6
18.4
214.3
31.6
General Procedures The instrumental analysis was carried out as de-
scribed previously.25)
Plant Material The roots of Asclepias syriaca L. (No. 2380M) were
collected from the botanical garden of the University of Shizuoka in Japan
in September, 1998 and identified by Prof. T. Noro. These dried materials
were stored in a herbarium.
21
Ester moieties
1e
2e
3e
4e
5e
6e
7e
8e
9e
165.9
119.4a)
144.8
135.1
128.6
129.3
130.6
129.3
128.6
164.5
—
153.8
127.0
165.9
119.4
144.8
135.1
128.5
129.3
130.5
129.3
128.5
167.8
129.4
137.7
12.3
14.3
—
—
—
—
Extraction and Isolation The dried roots of Asclepias syriaca L.
(1.15 kg) were extracted three times with MeOH under reflux. The extract
was concentrated under reduced pressure and the residue was suspended in
H2O. This suspension was extracted with diethyl ether, which was parti-
tioned into three fractions: an ether-soluble fraction, a water-soluble fraction,
and an ether–water emulsified fraction. The ether and ether–water emulsified
fractions were evaporated dry, and the total residue (33.3 g) was subjected to
silica gel CC with a CHCl3–MeOH (98 : 2—8 : 2) system to obtain five frac-
tions (A (7.71 g), B (2.70 g), C (3.23 g), D (2.81 g) and E (3.17 g)). Using
semi-preparative HPLC (Develosil-ODS-15/30 50 mm i.d.ꢆ100 cm, Devel-
137.1
c)
151.1
—
—
Measured in pyridine-d5 at 35 °C. a, b) Signal assignments may be interchanged in
each column. c) Overlapping with the pyridine-d5 signals.

February 2009
181
b
b
b
b
b

182
Vol. 57, No. 2
Syriacoside H (9): Amorphous powder. [a]D22 ꢀ11.4° (cꢂ0.87, MeOH).
[MꢀNa]ꢀ. HR-FAB-MS m/z: 935.4774 (Calcd for C50H72O15Na: 935.4769).
13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety (pyridine-d5
at 35 °C) d: 5.47 (1H, dd, 9.5, 2.0, H-1ꢃ), 5.18 (1H, dd, 9.5, 2.0, H-1ꢄ), 4.76
(1H, dd, 9.5, 2.0, H-1ꢅ), 4.64 (1H, br s, H-3ꢃ), 4.29 (1H, dq, 9.5, 6.5, H-5ꢃ),
4.20 (1H, dq, 9.5, 6.5, H-5ꢄ), 4.06 (1H, q, 3.0, H-3ꢄ), 3.58 (3H, s, C-3ꢄ-
OMe), 3.51 (1H, dd, 9.5, 3.0, H-4ꢃ), 3.47 (3H, s, C-3ꢅ-OMe), 3.45 (overlap-
ping, H-4ꢄ), 1.57 (3H, d, 6.0, H-6ꢅ), 1.44 (3H, d, 6.5, H-6ꢃ), 1.36 (3H, d, 6.5,
MeOH
UV l
nm (log e): 217 (4.12), 222 (4.05), 278 (4.28). FAB-MS m/z:
max
1065 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1065.5361 (Calcd for C56H82O18Na:
1065.5399). 13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety
(pyridine-d5 at 35 °C) d: 5.46 (1H, dd, 9.5, 2.0, H-1ꢃ), 5.37 (1H, dd, 9.5, 2.0,
H-1ꢄ), 5.15 (1H, dd, 9.5, 2.0, H-1ꢅ), 4.76 (1H, dd, 9.5, 2.0, H-1ꢄꢄ), 4.64 (1H,
br s, H-3ꢃ), 4.60 (1H, br s, H-3ꢄ), 4.29 (1H, dq, 9.5, 6.5, H-5ꢃ), 4.26 (1H, dq,
9.5, 6.5, H-5ꢄ), 4.19 (1H, dq, 9.5, 6.5, H-5ꢅ), 4.06 (1H, q, 3.0, H-3ꢅ), 3.58
(3H, s, C-3ꢅ-OMe), 3.57 (1H, dd, 9.5, 3.0, H-4ꢃ), 3.47 (3H, s, C-3ꢄꢄ-OMe),
3.46 (overlapping, H-4ꢅ), 3.44 (1H, dd, 9.5, 3.0, H-4ꢄ), 1.56 (3H, d, 6.0, H-
6ꢄꢄ), 1.43 (3H, d, 6.5, H-6ꢃ), 1.35 (3H, d, 6.5, H-6ꢅ), 1.34 (overlapping, H-
1
H-6ꢄ). The 13C- and H-NMR spectral data of the aglycone and ester moi-
eties were consistent with those of 1.
Syriacoside C (3): Amorphous powder. [a]D22 ꢀ13.5° (cꢂ0.34, MeOH).
UV lMmaexOH nm (log e): 217 (4.22), 222 (4.15), 277 (4.37). FAB-MS m/z: 935
[MꢀNa]ꢀ. HR-FAB-MS m/z: 935.4794 (Calcd for C50H72O15Na: 935.4769).
13C-NMR: shown in Table 2. 13C-NMR data of the sugar moiety (CDCl3 at
35 °C) d: 100.3 (C-1ꢄ), 98.2 (C-1ꢅ), 95.9 (C-1ꢃ), 82.8 (C-4ꢃ), 82.1 (C-4ꢄ),
78.8 (C-3ꢄ), 77.6 (C-3ꢅ), 72.5 (C-4ꢅ), 71.4 (C-5ꢄ), 71.1 (C-5ꢅ), 68.0 (C-5ꢃ),
66.6 (C-3ꢃ), 57.1 (C-3ꢅ-OMe), 56.8 (C-3ꢄ-OMe), 37.1 (C-2ꢃ), 36.3 (C-2ꢄ),
1
6ꢄ). The 13C- and H-NMR spectral data of the aglycone and ester moieties
were consistent with those of 1.
Syriacoside I (11): Amorphous powder. [a]D22 ꢀ33.1° (cꢂ0.80, MeOH).
MeOH
max
UV l
nm (log e): 217 (4.18), 222 (4.11), 278 (4.33). FAB-MS m/z:
1079 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1079.5565 (Calcd for C57H84O18Na:
1079.5555). 13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety
(pyridine-d5 at 35 °C) d: 5.31 (1H, dd, 9.5, 2.0, H-1ꢄ), 5.27 (1H, dd, 9.5, 2.0,
H-1ꢃ), 5.15 (1H, dd, 9.5, 2.0, H-1ꢅ), 5.07 (1H, dd, 9.5, 2.0, H-1ꢄꢄ), 4.59 (1H,
br s, H-3ꢄ), 4.24 (1H, dq, 9.5, 6.5, H-5ꢄ), 4.22 (1H, dq, 9.5, 6.5, H-5ꢃ), 4.19
(1H, dq, 9.5, 6.5, H-5ꢅ), 4.09 (1H, q, 3.0, H-3ꢃ), 4.09 (overlapping, H-5ꢄꢄ),
3.75 (1H, q, 3.0, H-3ꢄꢄ), 3.62 (3H, s, C-3ꢃ-OMe), 3.59 (3H, s, C-3ꢅ-OMe),
3.52 (1H, dd, 9.5, 3.0, H-4ꢃ), 3.47 (3H, s, C-3ꢄꢄ-OMe), 3.45 (1H, dd, 9.5,
3.0, H-4ꢄ), 3.43 (1H, dd, 9.5, 3.0, H-4ꢅ), 1.51 (3H, d, 6.5, H-6ꢄꢄ), 1.39 (3H,
d, 6.5, H-6ꢄ), 1.38 (3H, d, 6.5, H-6ꢃ), 1.32 (3H, d, 6.5, H-6ꢅ). The 13C- and
1H-NMR spectral data of the aglycone and ester moieties were consistent
with those of 1.
1
33.9 (C-2ꢅ), 18.4, 18.3, 18.2 (C-6ꢃ, C-6ꢄ, C-6ꢅ). H-NMR data of the sugar
moiety (CDCl3 at 35 °C) d: 4.93 (1H, dd, 9.5, 2.0, H-1ꢃ), 4.87 (1H, dd, 9.5,
2.0, H-1ꢅ), 4.50 (1H, dd, 9.5, 2.0, H-1ꢄ), 4.22 (1H, br s, H-3ꢃ), 3.80 (1H, dq,
9.5, 6.5, H-5ꢃ), 3.61 (1H, dq, 9.5, 6.5, H-5ꢅ), 3.43, 3.42 (each 3H, s, C-3ꢄ-
OMe, C-3ꢅ-OMe), 3.33 (1H, dq, 9.0, 6.0, H-5ꢄ), 3.20 (1H, dd, 9.5, 3.0, H-
4ꢃ), 3.16 (1H, t, 9.0, H-4ꢄ), 1.30 (3H, d, 6.5, H-6ꢅ), 1.28 (3H, d, 6.0, H-6ꢄ),
1.24 (3H, d, 6.5, H-6ꢃ). The 13C- and 1H-NMR spectral data of the aglycone
and ester moieties were consistent with those of 1.
Syriacoside D (4): Amorphous powder. [a]D22 ꢀ27.9° (cꢂ1.05, MeOH).
UV lMmaexOH nm (log e): 217 (4.15), 222 (4.08), 279 (4.32). FAB-MS m/z: 935
[MꢀNa]ꢀ. HR-FAB-MS m/z: 935.4795 (Calcd for C50H72O15Na: 935.4769).
13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety (pyridine-d5
at 35 °C) d: 5.32 (1H, dd, 9.5, 2.0, H-1ꢄ), 5.27 (1H, dd, 9.5, 2.0, H-1ꢃ), 5.12
(1H, dd, 9.5, 2.0, H-1ꢅ), 4.61 (1H, br s, H-3ꢄ), 4.26 (1H, dq, 9.5, 6.5, H-5ꢄ),
4.22 (1H, dq, 9.5, 6.5, H-5ꢃ), 4.10 (overlapping, H-3ꢃ, H-5ꢅ), 3.73 (1H, q,
3.0, H-3ꢅ), 3.62 (3H, s, C-3ꢃ-OMe), 3.53 (1H, dd, 9.5, 3.0, H-4ꢃ), 3.46 (1H,
dd, 9.5, 3.0, H-4ꢄ), 3.46 (3H, s, C-3ꢅ-OMe), 1.46 (3H, d, 6.0, H-6ꢅ) 1.40
Syriacoside J (14): Amorphous powder. [a]D22 ꢁ4.9° (cꢂ0.60, MeOH).
MeOH
max
UV l
nm (log e): 219 (3.94), 258 (sh), 263 (3.39), 269 (sh). FAB-MS
m/z: 1046 [MꢀH]ꢀ, 1068 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1046.5658,
1068.5508 (Calcd for C55H84NO18: 1046.5688, C55H83NO18Na: 1068.5508).
13C-NMR: shown in Tables 1 and 2. 1H-NMR data of the aglycone and ester
moieties (pyridine-d5 at 35 °C) d: 9.56 (1H, d, 2.0, H-3e), 8.86 (1H, dd, 4.5,
2.0, H-7e), 8.43 (1H, dt, 8.0, 2.0, H-5e), 7.35 (1H, dd, 8.0, 4.5, H-6e), 5.43
(1H, dd, 12.0, 4.5, H-12), 5.31 (1H, br s, H-6), 3.84 (1H, m, H-3), 2.10 (3H,
s, H-21), 2.00 (3H, s, H-18), 1.36 (3H, s, H-19). 13C-NMR data of the sugar
moiety (CDCl3 at 35 °C) d: 101.4 (C-1ꢅ), 99.7 (C-1ꢄ), 98.2 (C-1ꢄꢄ), 96.2 (C-
1ꢃ), 82.6, 82.5 (C-4ꢃ, C-4ꢄ), 82.2 (C-4ꢅ), 78.9 (C-3ꢅ), 77.6 (C-3ꢄꢄ), 77.1ꢆ2
(C-3ꢃ, C-3ꢄ), 72.5 (C-4ꢄꢄ), 71.1ꢆ2 (C-5ꢅ, C-5ꢄꢄ), 68.6, 68.3 (C-5ꢃ, C-5ꢄ),
58.3, 58.1 (C-3ꢃ-OMe, C-3ꢄ-OMe), 57.1 (C-3ꢄꢄ-OMe), 56.5 (C-3ꢅ-OMe),
36.4 (C-2ꢅ), 35.7ꢆ2 (C-2ꢃ, C-2ꢄ), 33.9 (C-2ꢄꢄ), 18.4, 18.3, 18.2ꢆ2 (C-6ꢃ, C-
6ꢄ, C-6ꢅ, C-6ꢄꢄ). 1H-NMR data of the sugar moiety (CDCl3at 35 °C) d: 4.88
(1H, dd, 9.5, 2.0, H-1ꢄꢄ), 4.85 (1H, dd, 9.5, 2.0, H-1ꢃ), 4.75 (1H, dd, 9.5, 2.0,
H-1ꢄ), 4.45 (1H, dd, 9.5, 2.0, H-1ꢅ), 3.86 (1H, dq, 9.5, 6.5, H-5ꢄ), 3.84 (1H,
dq, 9.5, 6.5, H-5ꢃ), 3.81 (1H, q, 3.0, H-3ꢃ), 3.78 (1H, q, 3.0, H-3ꢄ), 3.62 (1H,
q, 3.0, H-3ꢄꢄ), 3.60 (1H, dq, 9.5, 6.5, H-5ꢄꢄ), 3.45, 3.44 (each 3H, s, C-3ꢃ-
OMe, C-3ꢄ-OMe), 3.42 (3H, s, C-3ꢅ-OMe), 3.40 (3H, s, C-3ꢄꢄ-OMe), 3.29
(1H, dq, 9.0, 6.0, H-5ꢅ), 3.21 (2H, dd, 9.5, 3.0, H-4ꢃ, H-4ꢄ), 3.21 (overlap-
ping, H-4ꢄꢄ), 3.16 (1H, t, 9.0, H-4ꢅ), 1.30 (3H, d, 6.5, H-6ꢄꢄ), 1.29 (3H, d,
6.0, H-6ꢅ), 1.21 (6H, d, 6.5, H-6ꢃ, H-6ꢄ).
1
(3H, d, 6.5, H-6ꢄ), 1.38 (3H, d, 6.5, H-6ꢃ). The 13C- and H-NMR spectral
data of the aglycone and ester moieties were consistent with those of 1.
Syriacoside E (5): Amorphous powder. [a]D22 ꢁ18.3° (cꢂ0.47, MeOH).
UV lMmaexOH nm (log e): 217 (4.18), 222 (4.11), 278 (4.35). FAB-MS m/z: 935
[MꢀNa]ꢀ. HR-FAB-MS m/z: 935.4791 (Calcd for C50H72O15Na: 935.4769).
1
13C-NMR: shown in Table 2. H-NMR data of the sugar moiety (CDCl3 at
35 °C) d: 4.70 (1H, dd, 9.5, 2.0, H-1ꢅ), 4.59 (1H, dd, 9.5, 2.0, H-1ꢃ), 4.45
(1H, dd, 9.5, 2.0, H-1ꢄ), 3.60 (1H, m, H-3ꢃ), 3.43 (3H, s, C-3ꢄ-OMe), 3.43
(overlapping, H-5ꢄ), 3.40 (3H, s, C-3ꢅ-OMe), 3.40 (overlapping, H-3ꢄ), 3.32
(1H, dq, 9.0, 6.0, H-5ꢃ), 3.31 (1H, dq, 9.5, 6.0, H-5ꢅ), 3.22 (1H, t, 9.5, H-
4ꢄ), 2.96 (1H, t, 9.0, H-4ꢃ), 1.35 (3H, d, 6.0, H-6ꢅ), 1.34 (3H, d, 6.0, H-6ꢄ),
1.29 (3H, d, 6.0, H-6ꢃ). The 13C- and 1H-NMR spectral data of the aglycone
and ester moieties were consistent with those of 1.
Syriacoside F (6): Amorphous powder. [a]D22 ꢁ16.9° (cꢂ0.59, MeOH).
UV lMmaexOH nm (log e): 217 (4.18), 223 (4.11), 279 (4.35). FAB-MS m/z: 949
[MꢀNa]ꢀ. HR-FAB-MS m/z: 949.4967 (Calcd for C51H74O15Na: 949.4925).
13C-NMR: shown in Table 2. 13C-NMR data of the sugar moiety (CDCl3 at
35 °C) d: 100.2ꢆ2 (C-1ꢄ, C-1ꢅ), 97.9 (C-1ꢃ), 82.6, 82.5 (C-4ꢃ, C-4ꢄ), 80.8
(C-3ꢅ), 79.3, 79.4 (C-3ꢃ, C-3ꢄ), 75.5 (C-4ꢅ), 71.7 (C-5ꢅ), 71.1, 71.0 (C-5ꢃ,
C-5ꢄ), 56.8, 56.6 (C-3ꢃ-OMe, C-3ꢄ-OMe), 56.3 (C-3ꢅ-OMe), 36.6, 36.5 (C-
2ꢃ, C-2ꢄ), 35.5 (C-2ꢅ), 18.5, 18.4, 18.0 (C-6ꢃ, C-6ꢄ, C-6ꢅ). 1H-NMR data of
the sugar moiety (CDCl3 at 35 °C) d: 4.72 (1H, dd, 9.5, 2.0, H-1ꢅ), 4.67 (1H,
dd, 9.5, 2.0, H-1ꢄ), 4.53 (1H, dd, 9.5, 2.0, H-1ꢃ), 3.41, 3.40, 3.39 (each 3H, s,
C-3ꢃ-OMe, C-3ꢄ-OMe, C-3ꢅ-OMe), 3.33 (1H, dq, 9.0, 6.0, H-5ꢄ), 3.31 (2H,
dq, 9.0, 6.0, H-5ꢃ, H-5ꢅ), 3.18 (1H, t, 9.0, H-4ꢄ), 3.17 (1H, t, 9.0, H-4ꢃ), 3.15
(overlapping, H-4ꢅ), 1.35, 1.30 (each 3H, d, 6.0, H-6ꢃ, H-6ꢅ), 1.32 (3H, d,
6.0, H-6ꢄ). The 13C- and 1H-NMR spectral data of the aglycone and ester
moieties were in good agreement with those of 1.
Syriacoside K (15): Amorphous powder. [a]D22 ꢀ3.5° (cꢂ0.59, MeOH).
MeOH
max
UV l
nm (log e): 217 (4.18), 223 (4.11), 279 (4.37). FAB-MS m/z:
1093 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1093.5735 (Calcd for C58H86O18Na:
1093.5712). 13C-NMR: shown in Table 2. 13C-NMR data of the sugar moiety
(CDCl3 at 35 °C) d: 101.5, 101.4 (C-1ꢄ, C-1ꢄꢄ), 98.5 (C-1ꢅ), 96.1 (C-1ꢃ),
82.7ꢆ2 (C-4ꢃ, C-4ꢅ), 82.2 (C-4ꢄ), 80.7 (C-3ꢄꢄ), 78.9 (C-3ꢄ), 77.1ꢆ2 (C-3ꢃ,
C-3ꢅ), 75.5 (C-4ꢄꢄ), 71.6 (C-5ꢄꢄ), 71.2 (C-5ꢄ), 68.7, 68.5 (C-5ꢃ, C-5ꢅ), 58.3,
58.0 (C-3ꢃ-OMe, C-3ꢅ-OMe), 56.6 (C-3-OMe), 56.3 (C-3ꢄꢄ-OMe), 36.4 (C-
2ꢄ), 36.0 (C-2ꢃ), 35.6, 35.4 (C-2ꢅ, C-2ꢄꢄ), 18.4, 18.2ꢆ2, 18.0 (C-6ꢃ, C-6ꢄ, C-
6ꢅ, C-6ꢄꢄ). 1H-NMR data of the sugar moiety (CDCl3 at 35 °C) d: 4.95 (1H,
dd, 9.5, 2.0, H-1ꢅ), 4.85 (1H, dd, 9.5, 2.0, H-1ꢃ), 4.50 (1H, dd, 9.5, 2.0, H-
1ꢄꢄ), 4.44 (1H, dd, 9.5, 2.0, H-1ꢄ), 3.90 (1H, dq, 9.5, 6.5, H-5ꢅ), 3.86 (1H,
dq, 9.5, 6.5, H-5ꢃ), 3.80 (1H, q, 3.0, H-3ꢅ), 3.79 (1H, q, 3.0, H-3ꢃ), 3.45,
3.44 (each 3H, s, C-3ꢃ-OMe, C-3ꢅ-OMe), 3.40, 3.39 (each 3H, s, C-3ꢄ-OMe,
C-3ꢄꢄ-OMe), 3.35 (1H, m, H-3ꢄ), 3.28 (2H, dq, 9.5, 6.0, H-5ꢄ, H-5ꢄꢄ), 3.24
(1H, dd, 9.5, 3.0, H-4ꢅ), 3.22 (1H, dd, 9.5, 3.0, H-4ꢃ), 3.18 (1H, t, 9.0, H-4ꢄ),
1.32 (3H, d, 6.0, H-6ꢄꢄ), 1.28 (3H, d, 6.0, H-6ꢄ), 1.24 (3H, d, 6.5, H-6ꢅ), 1.22
Syriacoside G (8): Amorphous powder. [a]D22 ꢀ12.0° (cꢂ0.71, MeOH).
MeOH
max
UV l
nm (log e): 217 (4.20), 222 (4.13), 277 (4.36). FAB-MS m/z:
1111 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1111.5477 (Calcd for C57H84O20Na:
1111.5454). 13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety
(pyridine-d5 at 35 °C) d: 5.28 (1H, dd, 9.5, 2.0, H-1ꢃ), 5.12 (1H, dd, 9.5, 2.0,
H-1ꢄ), 5.12 (1H, d, 8.0, H-1ꢄꢄ), 4.69 (1H, dd, 9.5, 2.0, H-1ꢅ), 4.52 (1H, dd,
11.5, 2.5, H-6ꢄꢄ), 4.34 (1H, dd, 11.5, 5.5, H-6ꢄꢄ), 4.22 (overlapping, H-5ꢃ),
4.16 (1H, dq, 9.5, 6.5, H-5ꢄ), 4.09 (1H, q, 3.0, H-3ꢃ), 4.02 (1H, q, 3.0, H-3ꢄ),
3.95 (1H, m, H-5ꢄꢄ), 3.72 (1H, t, 9.0, H-4ꢅ), 3.66 (overlapping, H-5ꢅ), 3.62,
3.58 (each 3H, s, C-3ꢃ-OMe, C-3ꢄ-OMe), 3.53 (3H, s, C-3ꢅ-OMe), 3.51
(overlapping, H-4ꢃ), 3.43 (1H, dd, 9.5, 3.0, H-4ꢄ), 1.71 (3H, d, 6.0, H-6ꢅ),
1.40 (3H, d, 6.5, H-6ꢃ), 1.38 (3H, d, 6.5, H-6ꢄ). The 13C- and 1H-NMR spec-
tral data of the aglycone and ester moieties were consistent with those of 1.
1
(3H, d, 6.5, H-6ꢃ). The 13C- and H-NMR spectral data of the aglycone and
ester moieties were in good agreement with those of 1.
Syriacoside L (16): Amorphous powder. [a]D22 ꢀ6.5° (cꢂ0.59, MeOH).
MeOH
UV l
nm (log e): 217 (4.19), 222 (4.12), 278 (4.37). FAB-MS m/z:
max
1093 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1093.5730 (Calcd for C58H86O18Na:
1093.5712). 13C-NMR: shown in Table 2. 13C-NMR data of the sugar moiety
(CDCl3 at 35 °C) d: 101.4 (C-1ꢄ), 100.1 (C-1ꢅ), 98.2 (C-1ꢄꢄ), 96.1 (C-1ꢃ),

February 2009
183
(6H, d, 6.5, H-6ꢃ, H-6ꢄ), 1.31 (3H, d, 6.5, H-6ꢅ). The 13C- and 1H-NMR
spectral data of the aglycone and ester moieties were in good agreement
with those of 1.
82.7 (C-4ꢃ), 82.5, 82.4 (C-4ꢄ, C-4ꢅ), 79.2, 79.1 (C-3ꢄ, C-3ꢅ), 77.6 (C-3ꢄꢄ),
77.1 (C-3ꢃ), 72.5 (C-4ꢄꢄ), 71.3 (C-5ꢄꢄ), 71.1, 71.0 (C-5ꢄ, C-5ꢅ), 68.5 (C-5ꢃ),
58.3 (C-3ꢃ-OMe), 57.7 (C-3ꢄꢄ-OMe), 56.7ꢆ2 (C-3ꢄ-OMe, C-3ꢅ-OMe), 36.5,
36.4 (C-2ꢄ, C-2ꢅ), 35.9 (C-2ꢃ), 33.9 (C-2ꢄꢄ), 18.4ꢆ2, 18.3, 18.2 (C-6ꢃ, C-6ꢄ,
C-6ꢅ, C-6ꢄꢄ). 1H-NMR data of the sugar moiety (CDCl3 at 35 °C) d: 4.87
(1H, dd, 9.5, 2.0, H-1ꢄꢄ), 4.85 (1H, dd, 9.5, 2.0, H-1ꢃ), 4.66 (1H, dd, 9.5, 2.0,
H-1ꢅ), 4.44 (1H, dd, 9.5, 2.0, H-1ꢄ), 3.86 (1H, dq, 9.5, 6.5, H-5ꢃ), 3.79 (1H,
q, 3.0, H-3ꢃ), 3.62 (1H, q, 3.0, H-3ꢄꢄ), 3.60 (1H, dq, 9.5, 6.5, H-5ꢄꢄ), 3.45
(3H, s, C-3ꢃ-OMe), 3.42 (3H, s, C-3ꢄꢄ-OMe), 3.42, 3.39 (each 3H, s, C-3ꢄ-
OMe, C-3ꢅ-OMe), 3.31 (1H, dq, 9.0, 6.0, H-5ꢅ), 3.30 (1H, dq, 9.0, 6.0, H-
5ꢄ), 3.22 (1H, dd, 9.5, 3.0, H-4ꢃ), 3.17 (1H, t, 9.0, H-4ꢅ), 3.15 (1H, t, 9.0, H-
4ꢄ), 1.31 (3H, d, 6.5, H-6ꢄꢄ), 1.30 (3H, d, 6.0, H-6ꢅ), 1.29 (3H, d, 6.0, H-6ꢄ),
1.22 (3H, d, 6.5, H-6ꢃ). The 13C- and 1H-NMR spectral data of the aglycone
and ester moieties were in good agreement with those of 1.
Syriacoside R (24): Amorphous powder. [a]D22 ꢀ7.8° (cꢂ0.71, MeOH).
UV lMmaexOH nm (log e): 217 (4.16), 277 (4.31). FAB-MS m/z: 1255 [MꢀNa]ꢀ.
HR-FAB-MS m/z: 1255.6240 (Calcd for C64H96O23Na: 1255.6240). 13C-
1
NMR: shown in Table 2. H-NMR data of the sugar moiety (pyridine-d5 at
35 °C) d: 5.28 (1H, dd, 9.5, 2.0, H-1ꢃ), 5.13 (overlapping, H-1ꢄ), 5.12 (1H, d,
8.0, H-1ꢄꢅ), 4.89 (1H, dd, 9.5, 2.0, H-1ꢄꢄ), 4.69 (1H, dd, 9.5, 2.0, H-1ꢅ), 4.51
(1H, br d, 11.5, H-6ꢄꢅ), 4.34 (1H, m, H-6ꢄꢅ), 4.22 (1H, dq, 9.5, 6.5, H-5ꢃ),
4.17 (overlapping, H-5ꢄ), 4.09 (1H, q, 3.0, H-3ꢃ), 4.03 (1H, q, 3.0, H-3ꢄ),
3.93 (1H, m, H-5ꢄꢅ), 3.73 (1H, t, 9.0, H-4ꢄꢄ), 3.66 (1H, dd, 9.5, 3.0, H-4ꢄ),
3.63, 3.58, 3.55, 3.49 (each 3H, s, C-3ꢃ-OMe, C-3ꢄ-OMe, C-3ꢅ-OMe, C-3ꢄꢄ-
OMe), 3.52 (overlapping, H-4ꢃ), 1.74 (3H, d, 6.0, H-6ꢄꢄ), 1.43 (3H, d, 6.0,
H-6ꢅ), 1.41 (3H, d, 6.5, H-6ꢃ), 1.39 (3H, d, 6.5, H-6ꢄ). The 13C- and 1H-
NMR spectral data of the aglycone and ester moieties were in good agree-
ment with those of 1.
Syriacoside M (17): Amorphous powder. [a]D22 ꢀ12.0° (cꢂ0.74, MeOH).
MeOH
max
UV l
nm (log e): 217 (4.16), 222 (4.10), 279 (4.32). FAB-MS m/z:
1227 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1227.5897 (Calcd for C62H92O23Na:
1227.5927). 13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety
(pyridine-d5 at 35 °C) d: 5.46 (1H, dd, 9.5, 2.0, H-1ꢃ), 5.36 (1H, dd, 9.5, 2.0,
H-1ꢄ), 5.14 (1H, dd, 9.5, 2.0, H-1ꢅ), 5.11 (1H, d, 8.0, H-1ꢄꢅ), 4.67 (1H, dd,
9.5, 2.0, H-1ꢄꢄ), 4.63 (1H, br s, H-3ꢃ), 4.59 (1H, br s, H-3ꢄ), 4.51 (1H, br d,
11.5, H-6ꢄꢅ), 4.33 (1H, dd, 11.5, 5.5, H-6ꢄꢅ), 4.29 (1H, dq, 9.5, 6.5, H-5ꢃ),
4.24 (1H, dq, 9.5, 6.5, H-5ꢄ), 4.16 (1H, dq, 9.5, 6.5, H-5ꢅ), 3.94 (1H, m, H-
5ꢄꢅ), 3.71 (1H, t, 9.0, H-4ꢄꢄ), 3.57 (3H, s, C-3ꢅ-OMe), 3.53 (3H, s, C-3ꢄꢄ-
OMe), 3.51 (overlapping, H-4ꢃ), 3.42 (1H, dd, 9.5, 3.0, H-4ꢄ), 3.38 (1H, dd,
9.5, 3.0, H-4ꢅ), 1.71 (3H, d, 6.0, H-6ꢄꢄ), 1.42 (3H, d, 6.5, H-6ꢃ), 1.34 (3H, d,
Syriacoside S (25): Amorphous powder. [a]D22 ꢀ17.0° (cꢂ0.42, MeOH).
MeOH
max
UV l
nm (log e): 217 (4.16), 222 (4.09), 279 (4.33). FAB-MS m/z:
1255 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1255.6245 (Calcd for C64H96O23Na:
1255.6240). 13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety
(pyridine-d5 at 35 °C) d: 5.27 (2H, dd, 9.5, 2.0, H-1ꢃ, H-1ꢄꢄ), 5.11 (1H, dd,
9.5, 2.0, H-1ꢄ), 4.93 (1H, d, 8.0, H-1ꢄꢅ), 4.68 (1H, dd, 9.5, 2.0, H-1ꢅ), 4.57
(1H, br d, 11.5, H-6ꢄꢅ), 4.39 (1H, dd, 11.5, 5.5, H-6ꢄꢅ), 4.28 (1H, dq, 9.5,
6.5, H-5ꢄꢄ), 4.22 (overlapping, H-5ꢃ), 4.22 (1H, t, 8.0, H-3ꢄꢅ), 4.20 (1H, t,
8.0, H-4ꢄꢅ), 4.17 (overlapping, H-5ꢄ), 4.14 (overlapping, H-3ꢄꢄ), 4.09 (1H, q,
3.0, H-3ꢃ), 4.01 (1H, q, 3.0, H-3ꢄ), 3.99 (1H, t, 8.0, H-2ꢄꢅ), 3.97 (1H, m, H-
5ꢄꢅ), 3.67 (1H, dd, 9.5, 3.0, H-4ꢄꢄ), 3.62, 3.57, 3.54, 3.51 (each 3H, s, C-3ꢃ-
OMe, C-3ꢄ-OMe, C-3ꢅ-OMe, C-3ꢄꢄ-OMe), 3.52 (overlapping, H-4ꢅ), 3.50
(overlapping, H-4ꢃ), 3.44 (1H, dd, 9.5, 3.0, H-4ꢄ), 1.63 (3H, d, 6.5, H-6ꢄꢄ),
1.42 (3H, d, 6.0, H-6ꢅ), 1.39 (3H, d, 6.5, H-6ꢃ), 1.38 (3H, d, 6.5, H-6ꢄ). The
1
6.5, H-6ꢄ), 1.30 (3H, d, 6.5, H-6ꢅ). The 13C- and H-NMR spectral data of
the aglycone and ester moieties were in good agreement with those of 1.
Syriacoside N (19): Amorphous powder. [a]D22 ꢀ30.1° (cꢂ0.90, MeOH).
MeOH
max
UV l
nm (log e): 217 (4.18), 222 (4.11), 278 (4.35). FAB-MS m/z:
1241 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1241.6078 (Calcd for C63H94O23Na:
1241.6084). 13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety
(pyridine-d5 at 35 °C) d: 5.30 (overlapping, H-1ꢄ), 5.27 (1H, dd, 9.5, 2.0, H-
1ꢃ), 5.13 (1H, dd, 9.5, 2.0, H-1ꢅ), 5.07 (1H, dd, 9.5, 2.0, H-1ꢄꢄ), 4.93 (1H, d,
8.0, H-1ꢄꢅ), 4.57 (1H, br s, H-3ꢄ), 4.56 (1H, br d, 11.5, H-6ꢄꢅ), 4.38 (1H,
br d, 11.5, H-6ꢄꢅ), 4.23 (overlapping, H-5ꢄ, H-5ꢄꢄ), 4.22 (overlapping, H-5ꢃ),
4.15 (1H, dq, 9.5, 6.5, H-5ꢅ), 4.11 (1H, q, 3.0, H-3ꢄꢄ), 4.08 (1H, q, 3.0, H-
3ꢃ), 4.02 (1H, q, 3.0, H-3ꢅ), 3.97 (1H, m, H-5ꢄꢅ), 3.65 (1H, dd, 9.5, 3.0, H-
4ꢄꢄ), 3.61, 3.60, 3.53 (each 3H, s, C-3ꢃ-OMe, C-3ꢅ-OMe, C-3ꢄꢄ-OMe), 3.52
(overlapping, H-4ꢃ), 3.43 (1H, dd, 9.5, 3.0, H-4ꢄ), 3.37 (1H, dd, 9.5, 3.0, H-
4ꢅ), 1.60 (3H, d, 6.5, H-6ꢄꢄ), 1.37 (6H, d, 6.5, H-6ꢃ, H-6ꢄ), 1.27 (3H, d, 6.5,
1
13C- and H-NMR spectral data of the aglycone and ester moieties were in
good agreement with those of 1.
Syriacoside T (26): Amorphous powder. [a]D23 ꢀ31.4° (cꢂ0.54, MeOH).
FAB-MS m/z: 1207 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1207.6277 (Calcd for
1
C60H96O23Na: 1207.6240). The 13C- and H-NMR spectral data of the agly-
cone and ester moieties were in good agreement with those of 21. The 13C-
and 1H-NMR data of the sugar moiety were consistent with those of 25.
Acid Hydrolysis of a Mixture of Pregnane Glycosides The fraction of
pregnane glycosides eluted with the CHCl3–MeOH (98 : 2) system on a sil-
ica gel column (fraction B, 550 mg) was heated at 60 °C for 2.5 h with diox-
ane (8 ml) and 0.1 M H2SO4 (2 ml) to obtain the aglycones and sugars. After
hydrolysis, this reaction mixture was diluted with H2O and extracted with
EtOAc. The EtOAc layer was concentrated dry. Purification of the residue by
HPLC (YMC-ODS 10 mm i.d.ꢆ25 cm and 20 mm i.d.ꢆ25 cm, 67.5%
MeOH in water and 42.5, 45% MeCN in water) afforded ikemagenin (1a
(25 mg)), 5a,6-dihydroikemagenin (20a (4 mg)) and 12-O-tigloylisolineolon
(21a (11 mg)).
1
H-6ꢅ). The 13C- and H-NMR spectral data of the aglycone and ester moi-
eties were in good agreement with those of 1.
Syriacoside O (20): Amorphous powder. [a]D22 ꢀ28.9° (cꢂ0.52, MeOH).
MeOH
UV l
nm (log e): 217 (4.23), 222 (4.16), 279 (4.38). FAB-MS m/z:
max
1243 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1243.6233 (Calcd for C63H96O23Na:
1243.6240). 13C-NMR: shown in Table 1. 1H-NMR data of the aglycone and
ester moieties (pyridine-d5 at 35 °C) d: 7.96 (1H, d, 16.0, H-3e), 7.61 and
7.34 (5H, m, H-5e—9e), 6.76 (1H, d, 16.0, H-2e), 5.19 (1H, dd, 11.5, 4.0, H-
12), 3.89 (1H, m, H-3), 2.27 (3H, s, H-21), 1.98 (3H, s, H-18), 1.19 (3H, s,
H-19) The 13C- and 1H-NMR spectral data of the sugar moiety were consis-
tent with those of 19, but the C-1ꢃ and H-1ꢃ signals were observed at d 96.0
and d 5.30 (1H, dd, 9.5, 2.0), respectively.
The H2O layer was passed through an Amberlite IRA-60E column and the
eluate was concentrated dry. The residue was chromatographed on silica gel
with a CHCl3–MeOH–H2O (7 : 1 : 1.2 bottom layer and 7 : 1.5 : 1.2 bottom
layer) system to obtain cymarose, oleandrose, digitoxose, and canarose. As
to the absolute configuration, these monosaccharides were believed to have
D-forms based on their optical rotation values.
Syriacoside P (21): Amorphous powder. [a]D23 ꢀ40.3° (cꢂ1.04, MeOH).
FAB-MS m/z: 1193 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1193.6095 (Calcd for
C59H94O23Na: 1193.6084). 13C-NMR: shown in Table 1. 1H-NMR data of the
aglycone and ester moieties (pyridine-d5 at 35 °C) d: 7.14 (1H, qq, 7.0, 2.0,
H-3e), 5.33 (1H, br s, H-6), 5.06 (1H, dd, 12.0, 4.0, H-12), 3.84 (1H, m, H-
3), 3.21 (1H, dd, 9.5, 5.5, H-17), 2.24 (3H, s, H-21), 1.98 (3H, br s, H-5e),
1.72 (3H, br d, 7.0, H-4e), 1.54 (3H, s, H-18), 1.35 (3H, s, H-19). The 13C-
and 1H-NMR spectral data of the sugar moiety were consistent with those of
19.
D-Cymarose: [a]D22 ꢀ50.1° (cꢂ1.76, 24 h after dissolution in H2O).
(lit: [a]D21 ꢀ51.6° (cꢂ1.02, H2O)26)).
D-Oleandrose: [a]D22 ꢁ10.3° (cꢂ1.52, 24 h after dissolution in H2O).
(lit: [a]D ꢁ11° (cꢂ1.1, H2O)27)).
D-Digitoxose: [a]D22 ꢀ44.0° (cꢂ0.96, 24 h after dissolution in H2O).
(lit: [a]D26 ꢀ48.4° (cꢂ0.90, H2O)14)).
D-Canarose: [a]D22 ꢀ17.8° (cꢂ0.30, 24 h after dissolution in H2O).
Syriacoside Q (22): Amorphous powder. [a]D22 ꢀ14.8° (cꢂ0.63, MeOH).
(lit: [a]D21 ꢀ25° (cꢂ1.4, H2O)28)).
MeOH
UV l
nm (log e): 217 (4.18), 222 (4.11), 279 (4.34). FAB-MS m/z:
max
1241 [MꢀNa]ꢀ. HR-FAB-MS m/z: 1241.6090 (Calcd for C63H94O23Na:
1241.6084). 13C-NMR: shown in Table 2. 1H-NMR data of the sugar moiety
(pyridine-d5 at 35 °C) d: 5.31 (1H, dd, 9.5, 2.0, H-1ꢄ), 5.28 (1H, dd, 9.5, 2.0,
Acid Hydrolysis of Compounds 1—3, 5, 9, 11, 14, 15, and 16 Com-
pounds 1—3, 5, 9, 11, 14, 15, and 16 (ca. 0.5 mg) were each dissolved in
dioxane (80 ml) and 0.1 M H2SO4 (20 ml). The solutions were heated at 60 °C
H-1ꢃ), 5.15 (1H, dd, 9.5, 2.0, H-1ꢅ), 5.11 (1H, d, 8.0, H-1ꢄꢅ), 4.68 (1H, dd, for 45 min. After hydrolysis, each solution was neutralized on an Amberlite
9.5, 2.0, H-1ꢄꢄ), 4.60 (1H, br s, H-3ꢄ), 4.51 (1H, br d, 11.5, H-6ꢄꢅ), 4.34 (1H, IRA-60E column, and the eluate was concentrated dry. Each residue was
dd, 11.5, 5.5, H-6ꢄꢅ), 4.23 (1H, dq, 9.5, 6.5, H-5ꢄ), 4.22 (overlapping, H-5ꢃ), partitioned between H2O and EtOAc, and the EtOAc extract was analyzed
4.17 (overlapping, H-5ꢅ), 4.10 (1H, q, 3.0, H-3ꢃ), 4.01 (1H, q, 3.0, H-3ꢅ), using HPLC to identify the aglycone through a comparison with authentic
3.94 (1H, m, H-5ꢄꢅ), 3.71 (1H, t, 9.0, H-4ꢄꢄ), 3.62, 3.58, 3.54 (each 3H, s, C- samples. HPLC conditions: column, YMC-ODS 4.6 mm i.d.ꢆ25 cm; flow
3ꢃ-OMe, C-3ꢅ-OMe, C-3ꢄꢄ-OMe), 3.52 (overlapping, H-4ꢃ), 3.45 (1H, dd, rate, 1.0 ml/min; 70% MeOH in water; tR, 12.0 min (ikemagenin (1a)), 50%
9.5, 3.0, H-4ꢄ), 3.39 (1H, dd, 9.5, 3.0, H-4ꢅ), 1.71 (3H, d, 6.0, H-6ꢄꢄ), 1.38 MeOH in water; tR, 13.4 min (12-O-nicotinoyllineolon (14a)). Ikemagenin

184
Vol. 57, No. 2
was detected in 1—3, 5, 9, 11, 15, and 16. Similarly, 12-O-nicotinoylline- References
olon was identified in 14.
1) Brower L. P., (Ecological Chemistry), Scientific American, 220, 22—
29 (1969).
2) Cheung H. T. A., Watson T. R., J. Chem. Soc., Perkin Trans. 1, 1980,
2162—2168 (1980).
3) Cheung H. T. A., Watson T. R., Seiber J. N., Nelson C., J. Chem. Soc.,
Perkin Trans. 1, 1980, 2169—2173 (1980).
4) Cheung H. T. A., Chiu F. C. K., Watson T. R., Wells R. J., J. Chem.
Soc., Perkin Trans. 1, 1983, 2827—2835 (1983).
5) Cheung H. T. A., Nelson C. J., Watson T. R., J. Chem. Soc., Perkin
Trans. 1, 1988, 1851—1857 (1988).
6) Cheung H. T. A., Nelson C. J., J. Chem. Soc., Perkin Trans. 1, 1989,
1563—1570 (1989).
7) Abe F., Mohri Y., Yamauchi T., Chem. Pharm. Bull., 39, 2709—2711
(1991).
8) Abe F., Mohri Y., Yamauchi T., Chem. Pharm. Bull., 40, 2917—2920
(1992).
9) Roy M. C., Chang F.-R., Huang H.-S., Chiang M. Y.-N., Wu Y.-C., J.
Nat. Prod., 68, 1494—1499 (2005).
Subsequently, the H2O layer was reduced with NaBH4 (ca. 1 mg) for 1 h at
room temperature. The following procedures were described in a previous
report.18) Cymaritol acetate, oleandritol acetate, digitoxitol acetate, and ca-
naritol acetate were detected by GC. GC conditions: column, Supelco SP-
2380TM capillary column 0.25 mmꢆ30 m; carrier gas, N2; column tempera-
ture 200 °C; tR, 7.2 min (cymaritol acetate), 8.1 min (oleandritol acetate),
10.4 min (digitoxitol acetate), 11.6 min (canaritol acetate). Cymaritol acetate
was detected in 2, 3, 9, 11, 14, 15, and 16. Oleandritol acetate was identified
in 1—3, 5, 9, 14, 15, and 16. Digitoxitol acetate was found in 1—3, 9, and
11. Canaritol acetate was observed in 5.
Acid Hydrolysis of a Mixture of Pregnane Glycosides to Determine
the Configuration of Glucose The fraction of pregnane glycosides eluted
with the CHCl3–MeOH (98 : 2) system on a silica gel column (fraction D,
10 mg) was heated at 98 °C for 1 h with 0.05 M HCl and dioxane (0.2 ml
each). After hydrolysis, this reaction mixture was diluted with H2O and ex-
tracted with EtOAc. The H2O layer was neutralized on Amberlite IRA-60E
column, and the eluate was concentrated dry. The residue was stirred with D-
cysteine methyl ester hydrochloride hexamethyldisilazane and trimethylsi- 10) Brown P., von Euw J., Reichstein T., Stockel K., Watson T. R., Helv.
lylchloride in pyridine, as described.29,30) After reactions, the supernatant
was subjected to GC. GC conditions: column, GL capillary column TC-1
0.32 mmꢆ30 m (GL Science Co.), carrier gas, N2; column temperature
210 °C; tR 16.5 min (D-glucose), 15.6 min (L-glucose). D-Glucose was de-
tected in the mixture of pregnane glycosides.
Chim. Acta, 62, 412—440 (1979).
11) Mitsuhashi H., Hayashi K., Tomimoto K., Chem. Pharm. Bull., 18,
823—831 (1970).
12) Cheung H. T. A., Watson T. R., Lee S. M., McChesney M. M., Seiber
J. N., J. Chem. Soc., Perkin Trans. 1, 1986, 61—65 (1986).
Acid Hydrolysis of Compounds 4, 6, 8, 17, 19—22, 24, 25, and 26 13) Warashina T., Noro T., Natural Medicines, 57, 185—188 (2003).
Solutions of compounds 4, 6, 8, 17, 19—22, 24, 25, and 26 (ca. 0.5 mg) in
dioxane and 0.05 M HCl (50 ml each) were heated at 98 °C for 1 h. The sub-
sequent procedures, and HPLC and GC conditions for the detection of the
14) Abe F., Mohri Y., Okabe H., Yamauchi T., Chem. Pharm. Bull., 42,
1777—1783 (1994).
15) Warashina T., Noro T., Chem. Pharm. Bull., 42, 322—326 (1994).
component aglycones and sugars were described above and as follows: 16) Abe F., Yamauchi T., Chem. Pharm. Bull., 48, 1017—1022 (2000).
HPLC conditions: column, YMC-ODS-AM 4.6 mmꢆ25 cm; flow rate, 17) Warashina T., Noro T., Chem. Pharm. Bull., 48, 516—524 (2000).
1.0 ml/min; 70% MeOH in water; tR, 10.4 min (ikemagenin (1a)), 11.2 min
(12-O-tigloylisolineolon (21a)), 12.0 min (5a,6-dihydroikemagenin (20a)).
18) Warashina T., Noro T., Chem. Pharm. Bull., 56, 315—322 (2008).
19) Warashina T., Noro T., Chem. Pharm. Bull., 43, 977—982 (1995).
Ikemagenin was detected in 4, 6, 8, 17, 19, 22, 24, and 25. 5a,6-Dihy- 20) Yamagishi T., Mitsuhashi H., Chem. Pharm. Bull., 20, 2070—2071
droikemagenin and 12-O-tigloylisolineolon were found in 20 and in 21 and
26, respectively. GC conditions: column, Supelco SP-2380TM capillary col-
umn 0.25 mmꢆ30 m, carrier gas, N2; column temperature 250 °C; tR
11.8 min (glucitol acetate). Cymaritol acetate was detected in 4, 8, 17, 19—
(1972).
21) Kasai R., Okihara M., Asakawa J., Mizutan K., Tanaka O.,
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22, 24, 25, and 26. Oleandritol acetate was found in 6, 8, 17, 22, 24, 25, and 23) Warashina T., Noro T., Phytochemistry, 44, 917—923 (1997).
26. Digitoxitol acetate and glucitol acetate were observed in 4, 17, and 19—
22, and in 8, 17, 19—22, and 24—26, respectively.
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27—35 (2007).
Enzymatic Hydrolysis of Compounds 8, 17, 19, 22, 24, and 25 Com- 25) Iizuka M., Warashina T., Noro T., Chem. Pharm. Bull., 49, 282—286
pounds 8, 17, 19, 22, 24, and 25 (ca. 1 mg) were dissolved in EtOH (30 ml)
and H2O (0.3 ml), respectively, then cellulase (Sigma Chem. Co.) (ca.
10 mg) was added to each solution. The mixtures were stirred at 40 °C for
(2001).
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7 d. After hydrolysis, the reaction mixtures were diluted with H2O and ex- 27) Nakagawa T., Hayashi K., Wada K., Mitsuhashi H., Tetrahedron, 39,
tracted with EtOAc, and each EtOAc extract was analyzed by HPLC for
identification via comparison with authentic samples. HPLC conditions: col-
umn, YMC-ODS-AM 4.6 mmꢆ25 cm; flow rate, 1.0 ml/min; 80% MeOH in
water; tR, 14.2 min (7), 12.0 min (9), 19.0 min (11), 17.6 min (22e), 19.4 min
(12), 20.6 min (13). Compounds 7, 9, 11, 22e, 12, and 13 were detected in
the EtOAc extracts of 8, 17, 19, 22, 24, and 25, respectively.
607—612 (1983).
28) Miyamoto M., Kawamatsu Y., Shinohara M., Nakadaira Y., Nakanishi
K., Tetrahedron, 22, 2785—2799 (1966).
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(1987).
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