Three new pentasaccharide resin glycosides from the roots of sweet potato (Ipomoea batatas)

Article abstract of DOI:10.1248/cpb.56.1670

Three new pentasaccharide resin glycosides, batatosides III-V (1-3), were isolated from the roots of Sweet potato (Ipomoea batatas). Saponification of the crude resin glycoside mixture yielded substituents and simonic acid B. The structures of the isolate

Full text of DOI:10.1248/cpb.56.1670

1670
Chem. Pharm. Bull. 56(12) 1670—1674 (2008)
Vol. 56, No. 12
Three New Pentasaccharide Resin Glycosides from the Roots of
Sweet Potato (Ipomoea batatas)
c
Yong-Qin YIN,a,b Xue-Feng HUANG,a Ling-Yi KONG,*,a and Masatake NIWA
a Department of Natural Medicinal Chemistry, China Pharmaceutical University; 24 Tong Jia Xiang, Nanjing, Jiangsu
210009, P. R . China: b Department of Chinese Medicine, Guangdong Pharmaceutical University; 280 Wai Huan Dong Lu,
Guangdong 510006, P. R. China: and c Faculty of Pharmacy, Meijo University; Tempaku, Nagoya 468–8503, Japan.
Received June 24, 2008; accepted September 11, 2008
Three new pentasaccharide resin glycosides, batatosides III—V (1—3), were isolated from the roots of Sweet
potato (Ipomoea batatas). Saponification of the crude resin glycoside mixture yielded substituents and simonic
acid B. The structures of the isolated compounds (1—3) were established through spectroscopic analyses, includ-
ing high field NMR spectroscopy and HR-ESI-MS, and chemical correlation. The major characteristics of 3 are
the presence of three different substituents, especially the substituent of cinnamic acid was seldom. The mono-
saccharides of 1—3 were proved by GC-MS and the absolute configuration of aglycone was further established
as S by Mosher’s method with R-methyloxyphenylacetic acid (MPA) and S-MPA.
Key words Ipomoea batatas; resin glycoside; pentasaccharide
The genus Ipomoea (Convolvulaceae) was shown to be a hydrolysates were proved by GC-MS method, respectively.
rich source of “resin glycosides” which exhibited antibacter- The configuration of 11S was assigned to 1 based on
ial,1) cytotoxic,2,3) antifugal,4) and anti-tuberculosis activity.5) Mosher’s method with S-methyloxyphenylacetic acid (MPA)
Sweet potato, I. batatas (L.) LAM. was an important food and R-MPA. Alkaline hydrolysis of compound 1 afforded si-
crop whose production ranks the seventh in global market.6) monic acid B (4)12) and a mixture which were identified as
The aerial part of the sweet potato is used as vegetable and (S)-2-methylbutyric acid (Mba) and trans-cinnamic acid
the underground part is used as food or raw material in in- (Cna), respectively, by GC-MS, compared of their optical ro-
1
dustry.7) It is known in China as “Shanyu”, “Hongshu”, tations with those of authentic samples. The H-NMR spec-
“Digua” and “Hongshao” and cultured nationwide. Chinese trum (Table 1) of 1 exhibited a pair of trans-coupled olefinic
people used it also as herb to promote the production of protons at d 6.53 (d, Jꢁ15.9 Hz, H-2 of Cna) and 7.81 (d,
body fluid, haemostasis and apocenosis for centuries.8) Jꢁ15.9 Hz, H-3 of Cna), and dH 7.27—7.45 (m, C6H5) as-
Recently, some of resin glycosides were described from I. cribed to five phenyl protons. The 13C-NMR spectrum dis-
batatas.9—11) In the present paper, we report the isolation played signals for an a, b-unsaturated lactone unit at dC
and structure elucidation of three new resin glycosides ba- 118.4, 145.5, 166.3. Based on the analysis above, 1 contained
tatosides III—V (1—3) from this plant continuously. The a 3-phenylprop-2-enoyl (Cna) moiety. The upfield protons at
major structural characteristics of 3 are the presence of dH 0.82 (t, Jꢁ7.0 Hz, H-4 of Mba), 1.07 (d, Jꢁ7.0 Hz, CH3ꢃ-
three different substituents, especially the substituent of 2 of Mba), 2.38 (tq, Jꢁ7.0, 7.0 Hz, H-2 of Mba) displayed in
cinnamic acid (Cna) was seldom. Comparing compounds 1 one spin system in the TOCSY spectra, suggesting the pres-
and 2 with the similar resin glycosides,9—11) 1 and 2 were hy- ence of a (S)-2-methylbutyryl moiety. Similarly, the protons
drophilic.
at dH 0.80, 1.14, 2.40 composed the second (S)-2-methylbu-
tyryl moiety. The protons in the region of dH 4.00—6.4 were
assigned by 1H-NMR, 13C-NMR, TOCSY, HSQC, and
Results and Discussion
A 95% EtOH extract of the dried roots of I. batatas was HMBC spectra. The HMQC spectrum of 1 indicated that
partitioned between CHCl3 and H2O to afford a resinous anomeric carbons at 104.3, 98.8, 99.4, 103.7, and 104.7 ppm
fraction which was chromatographed over Si gel, Rp-18, were correlated with the anomeric protons at 4.75 (d,
Sephadex LH-20 and purified by preparative HPLC to afford Jꢁ7.4 Hz), 5.49 (br s), 6.06 (br s), 5.96 (br s), and 5.68 (br s)
compounds 1—3.
ppm, respectively. A combination of one- and two-dimen-
Batatoside III (1) {[a]D20 ꢀ18.7° (cꢁ0.4, MeOH)} was ob- sional NMR techniques allowed all protons to be assigned
tained as white amorphous powder. The molecular formula, sequentially within each saccharide system, leading to the
C65H102O25, was inferred from negative HR-ESI-MS ([Mꢂ identification of one fucopyranosyl and four rhamnopyra-
Na]ꢂ at m/z 1305.6627), and it was supported by 13C-NMR nosyl units as the monosaccharides present in 1. The
and DEPT spectroscopy. The IR spectrum showed absorp- anomeric configuration for the sugar moieties were defined
tions for hydroxyl (3445 cmꢀ1), methyl (2933, 2859 cmꢀ1), as b for fucopyranosyl, a for rhamnopyranosyl from their
carbonyl (1723 cmꢀ1), and phenyl (1636 cmꢀ1) groups. A coupling constants of 7.4 Hz and C-5 chemical shift,13) re-
pair of trans-coupled olefinic protons, five protons of aroma, spectively. The connectivities between sugar moieties were
and many protons of saccharides and pal-chains existed in determined from the following HMBC correlations: C-1 of
1H-NMR spectrum, so compound 1 was possible to be a kind fucose (dC 104.3) and H-11 of the aglycon (dH 3.87), C-2 of
of resin glycoside. Compound 1 was hydrolyzed with alka- fucose (dC 80.3) and H-1 of rhamnose (dH 5.49), C-1 of
line to detect the substituents and acid hydrolysis to deter- rhamnoseꢃ (dC 99.4) and H-4 of rhamnose (dH 4.25), C-1 of
mine the absolute configurations of sugars successively, then rhamnoseꢄ (dC 103.7) and H-4 of (dH 4.30) and C-1 of rham-
∗ To whom correspondence should be addressed. e-mail: lykong@jlonline.com
© 2008 Pharmaceutical Society of Japan

December 2008
1671
Table 1. 1H- (600 MHz) and 13C-NMR (150 MHz) Spectral Data of
Batatoside III (1), Batatoside IV (2) in C5D5N (d in ppm, J in Hz)
1
2
Position
1H-NMR
13C-NMR
1H-NMR
13C-NMR
Fuc-1
2
3
4
5
6
4.75 d (7.4)
104.3
80.3
73.3
73.0
70.6
17.4
98.8
73.1
69.8
80.6
70.8
19.5
99.4
73.4
79.5
80.2
68.3
18.9
103.7
70.1
4.78 d (7.8)
101.6
73.5
76.6
73.5
71.2
17.2
100.2
69.9
78.1
4.16 dd (7.4, 9.6)
4.10 d (3.2, 9.6)
3.99 d (3.2)
3.77 br q (6.2)
1.50 d (6.2)
5.49 br s
6.02 br s
5.03 dd (3.0, 9.3)
4.25 dd (9.3, 9.3)
4.50 dd (9.3, 6.2)
1.61 d (6.2)
4.49 dd (7.8, 9.5)
4.17 dd (9.5, 3.4)
3.90 d (3.4)
3.79 br q (6.4)
1.49 d (6.4)
6.31 br s (1.5)
5.27 br s
Rha-1
Fig. 1. Structure of Batatoside III (1)
2
3
4
5
6
5.61*
4.65 dd (10.0, 10.0) 76.3
4.97 dd (10.0, 6.3)
1.57 d (6.3)
5.59 br s
5.76 br s
4.49 dd (3.0, 9.5)
4.26 dd (9.5, 9.5)
4.29 dd (9.5, 6.1)
1.58 d (6.1)
5.87 br s
4.61 br s
4.34 dd (3.0, 10.0)
4.26 dd (10.0, 10.0) 73.6
4.29 dd (10.0, 6.3)
1.39 d (6.3)
5.61 br s
68.0
18.8
98.8
72.8
79.4
79.6
68.7
19.2
103.8
72.7
72.5
Rhaꢃ-1 6.06 br s
2
3
4
5
6
5.99 br s
4.69 dd (3.1, 9.4)
4.30 dd (9.4, 9.4)
4.36 dd (9.4, 6.2)
1.66 d (6.2)
Rhaꢄ-1 5.96 br s
2
3
4
5
6
4.94 br s
5.92 dd (3.0, 10.0) 73.5
6.06 dd (10.0, 10.0) 71.5
4.45 dd (10.0, 6.2) 68.5
70.7
18.6
104.6
72.5
72.5
73.5
70.5
18.3
174.6
33.9
1.43 d (6.2)
17.8
104.7
73.9
72.6
72.5
68.6
18.5
173.1
34.3
Rhaꢅ-1 5.68 br s
2
3
4
5
6
4.79 br s
4.74 br s
4.40 dd (3.1, 9.0)
4.20 dd (9.0, 9.0)
4.27 dd (9.0, 6.2)
1.55 d (6.2)
4.42 dd (3.4, 9.5)
4.18 dd (9.5, 9.5)
4.29 dd (9.5, 6.1)
1.69 d (6.1)
Fig. 2. Structures of Batatoside IV (2), Batatoside V (3)
Ag-1
2
2.19*
2.42*
2.25 ddd
(4.3, 7.1, 15.5)
2.81 ddd
noseꢄ, as shown by the correlation between the carbonyl at
dC 166.3 with H-3 of rhamnoseꢄ at dH 5.92, and another (S)-
2-methylbutanoyl was placed at C-4 of rhamnoseꢄ, as shown
by the correlation between the carbonyl at dC 175.4 with H-4
of rhamnoseꢄ at dH 6.06. The position of the jalapinolic acid
unit was determined by the long-range correlations with the
lactone carbonyl at dC 173.1 with the H-2 of rhamnose (dH
6.02). Based on these results, batatoside III (1) was eluci-
dated as (S)-jalapinolic acid 11-O-a-L-rhamnopyranosyl-
(1→3)-O-[3-O-trans-4-O-(S)-2-methylbutyryl-a -L-
rhamnopyranosyl-(1→4)]-O-[2-O-(S)-2-methylbutyryl]-a-L-
rhamnopyranosyl-(1→4)-O-a-L-rhamnopyranosyl-(1→2)-O-
b-D-fucopyranoside, intramolecular 1,2ꢄ-ester (Fig. 1).
(4.3, 7.1, 15.5)
3.87 m
0.91 t (6.8)
11
16
Cna-1
2
3
Mba-1
2
3.87*
0.87 t (6.8)
82.3
14.3
79.7
14.5
166.3
118.4
145.5
175.9
41.6
16.9
11.8
175.4
41.5
16.8
6.53 d (15.9)
7.81 d (15.9)
175.4
41.4
16.9
11.8
2.45 m
2.35 tq (7.5, 7.5)
1.12 d (7.0)
0.87 t (7.5)
2-Me 1.14 d (7.0)
4
Mba-1
2
2-Me
4
0.82 t (7.0)
2.38 m
1.07 d (7.0)
0.83 t (7.0)
11.8
Batatoside IV (2) {[a]D20 ꢀ38.1° (cꢁ0.5, MeOH)} was ob-
tained as white amorphous powder, giving the molecular for-
mula C51H88O23 from HR-ESI-MS spectrometric analyses
([MꢂNa]ꢂ at m/z 1091.5616). The IR spectrum showed ab-
sorptions for hydroxyl (3448 cmꢀ1), methyl (2929, 2856
cmꢀ1), carbonyl (1736 cmꢀ1), and phenyl (1636 cmꢀ1) groups.
The 1H-NMR spectrum of compound 2 was similar to 1. Com-
Chemical shifts (d) are in ppm relative to TMS. The spin coupling (J) is given in
parentheses (Hz). All assignments are based on 1H–1H TOCSY, HSQC, and HMBC ex-
periments. Chemical shifts marked with an asterisk (∗) indicate overlapped signals.
Spin-coupled patterns are designated as follows: sꢁsinglet, br sꢁbroad singlet, dꢁdou-
blet, tꢁtriplet, mꢁmultiplet, qꢁquartet. Abbreviations: Fucꢁfucose; Rhaꢁrhamnose;
Agꢁ11-hydroxyhex-adecanoyl; Cnaꢁtrans-cinnamoyl; Mbaꢁ(S)-2-methylbutanoyl.
noseꢅ (dC 104.7) and H-3 of rhamnoseꢃ (dH 4.69). The pound 2 was hydrolyzed with base and acid, then the hy-
HMBC spectrum of 1 also permitted the unambiguous as- drolysates were detected with authentic samples by GC-MS.
signment of the esterified positions of the oligosaccharide Alkaline hydrolysis of 2 afforded (S)-2-methylbutyric acid
core by the correlations between the carbonyl ester group and simonic acid B. Acylation sites of substituent and agly-
with their corresponding vicinal proton (2JCH) and the pyra- cone were identified by HMBC correlations between the H-2
nose ring proton (3JCH). In 1, (S)-2-methylbutanoyl was of rhamnoseꢃ (dH 5.76) and dC 175.4, and between the H-3
placed at C-2 of rhamnoseꢃ, as shown by the correlation be- of rhamnose (dH 5.61) and dC 174.6. From the above results,
tween the carbonyl at dC 175.9 and H-2 of rhamnoseꢃ at dH the structure of 2 was elucidated as (S)-jalapinolic acid 11-O-
5.99; a trans-cinnamoyl residue was located at C-3 of rham- a-L-rhamnopyranosyl-(1→3)-O-a-L-rhamnopyranosyl-

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Vol. 56, No. 12
Table 2. 1H- (600 MHz) and 13C-NMR (150 MHz) Spectral Data of
Batatoside V (3), Simonic Acid B (4) in C5D5N (d in ppm, J in Hz)
3
4
Position
1H-NMR
13C-NMR
1H-NMR
13C-NMR
Fuc-1
2
3
4
5
6
4.79 d (7.8)
101.5
73.6
76.6
73.6
71.3
17.1
100.2
69.9
78.0
4.78 d (7.3)
101.2
74.9
76.7
73.5
71.2
17.2
101.3
73.2
72.7
80.4
67.1
19.1
102.9
72.0
82.6
78.7
68.7
18.3
104.5
72.6
72.7
73.7
70.1
18.9
103.3
72.7
72.8
74.0
70.4
18.6
176.3
35.7
4.52 dd (7.8, 9.5)
4.18 dd (9.5, 3.4)
3.90 d (3.4)
3.80 br q (6.4)
1.49 d (6.4)
6.33 br s
5.31 br s
5.62*
4.62 dd (10.0, 10.0) 77.3
5.02 dd (10.0, 5.9) 68.2
1.58 d (5.9)
4.46 dd (7.3, 9.7)
4.13 dd (9.7, 3.1)
3.91 d (3.1)
3.77 br q (6.2)
1.49 d (6.2)
6.22 br s
4.63*
4.63*
4.20 dd (9.5, 9.5)
4.86*
1.55 d (6.6)
6.15 br s
Fig. 3. Structure of Simonic Acid B (4)
Rha-1
2
3
4
5
6
19.1
99.0
72.8
79.6
79.0
68.2
18.7
100.2
73.8
Rhaꢃ-1 5.67 br s
2
3
4
5
6
5.79 br s
4.86*
4.58 dd (3.0, 9.5)
4.24 dd (9.5, 9.5)
4.36 dd (9.5, 5.8)
1.60 d (5.8)
4.52 dd (2.6, 9.1)
4.46 dd (9.1, 8.6)
4.28 dd (8.6, 6.1)
1.58 d (6.1)
5.66 br s
Rhaꢄ-1 5.81 br s
2
3
4
5
6
5.99 br s
4.66 br s
4.55 dd (3.0, 10.0) 67.8
5.77 dd (10.0, 10.0) 75.0
4.67 dd (10.0, 6.4) 68.0
4.35 dd (2.6, 9.6)
4.28 dd (9.6, 9.6)
4.32 dd (9.6, 6.1)
1.52 d (6.1)
5.92 br s
Fig. 4. Key HMBC Correlations from H to C for Compound 1
1.52 d (6.4)
17.9
104.2
72.6
72.7
73.6
70.9
18.7
174.7
33.5
Rhaꢅ-1 5.59 br s
to each spin-system. The connections sites were determined
by HMBC experiment. In 3, dodecanoic residue was placed
at C-2 of rhamnoseꢃ, as shown by the correlation between the
carbonyl at dC 172.8 and H-2 rhamnoseꢃ at dH 5.79; a trans-
cinnamoyl residue was located at C-2 of rhamnoseꢄ, as
shown by the correlation between the carbonyl at dC 166.6
with H-2 of rhamnoseꢄ at dH 5.99, and decanoic was placed
at C-4 of rhamnoseꢄ, as shown by the correlation between the
carbonyl at dC 173.4 with H-4 of rhamnoseꢄ at dH 5.77. From
the above results, the structure of 3 was established as (S)-
jalapinolic acid 11-O-a-L-rhamnopyranosyl-(1→3)-O-[2-O-
trans-cinnamoyl-4-O-n-decanoyl-a-L-rhamnopyranosyl-
(1→4)]-O-[2-O-n-dodecanoyl]-a -L-rhamnopyranosyl-
(1→4)-O-a-L-rhamnopyranosyl-(1→2)-O-b-D-fucopyrano-
side, intramolecular 1,3ꢄ-ester (Fig. 2).
2
3
4
5
6
4.90 br s
4.95 br s
4.40 dd (3.4, 9.5)
4.18 dd (9.5, 9.5)
4.25 dd (9.5, 6.0)
1.69 d (6.0)
4.52 dd (2.6, 9.5)
4.20 dd (9.5, 9.5)
4.71 dd (9.5, 6.5)
1.53 d (6.5)
2.50 t (7.3)
Ag-1
2
2.26 m
2.97 m
3.87 m
0.99 t (6.8)
11
16
Cna-1
2
79.2
14.4
3.90 br s
0.90 t (6.3)
77.9
14.4
166.6
118.3
145.5
173.4
34.3
14.2
172.8
34.5
6.49 d (15.9)
7.84 d (15.9)
3
Deca-1
2
10
2.39 m
0.84 m
Dodeca-1
2
2.47 m
12
0.84 t (7.0)
14.2
Experimental
General Procedure Optical rotations were measured with a JASCO P-
1020 polarimeter. IR spectra and UV spectra were recorded on a Nicolet Im-
pact-410 spectrometer and Shimadzu UV-2501PC. 1D and 2D NMR spectra
were carried out with a Bruker ACF-600 NMR spectrometer (1H: 600 MHz,
13C: 150 MHz) in pyridine-d5. Chemical shifts are reported in ppm as d val-
ues and TMS was used as internal standard. Mass spectra were obtained on a
MS Agilent 1100 series LC/MSD ion trap mass spectrometer (ESI-MS), an
Agilent TOF-MSD 1946D spectrometer, and a Micro Q-TOF-MS. TLC was
performed on pre-coated silica gel 60 F254 (Qingdao Haiyang Chemical Co.,
Ltd.) and detected by spraying with 10% H2SO4–EtOH. Silica gel H (Qing-
dao Haiyang Chemical Co., Ltd.), sephadex LH-20 (Pharmacia), and Rp-C18
(40—63 mm, Fuji) were used for column chromatography. Preparative
HPLC was carried out using Agilent 1100 series instrument with a Shim-
park Rp-C18 column (200ꢆ20 mm i.d.).
Chemical shifts (d) are in ppm relative to TMS. The spin coupling (J) is given in
parentheses (Hz). All assignments are based on 1H–1H TOCSY, HSQC, and HMBC ex-
periments. Chemical shifts marked with an asterisk (∗) indicate overlapped signals.
Spin-coupled patterns are designated as follows: sꢁsinglet, br sꢁbroad singlet, dꢁdou-
blet, tꢁtriplet, mꢁmultiplet, qꢁquartet. Abbreviations: Fucꢁfucose; Rhaꢁrhamnose;
Agꢁ11-hydroxyhex-adecanoyl; Cnaꢁtrans-cinnamoyl; Decaꢁn-decanoyl; Dodecaꢁn-
dodecanoyl.
(1→4)]-O-[2-O-(S)-2-methylbutyryl]-a-L-rhamnopyranosyl-
(1→4)-O-a-L-rhamnopyranosyl-(1→2)-O-b-D-fucopyra-
noside, intramolecular 1,3ꢄ-ester (Fig. 2).
Batatoside V (3) {[a]D20 ꢀ28.1° (cꢁ0.4, MeOH)} was ob-
tained as white amorphous powder, giving the molecular
formula C77H126O25 from HR-ESI-MS spectrometric analyses
Plant Material The roots of I. batatas were collected in Yanlin Country,
([MꢂNa]ꢂ at m/z 1473.8423). The IR spectrum exhibited ab- Hunan Province, People’s Republic of China in September, 2004 and identi-
sorptions for hydroxyl (3443 cmꢀ1), methyl (2929,
fied by Prof. Min-jian Qin, Department of Medicinal Plants, China Pharma-
ceutical University. A voucher specimen (No. 040912) is deposited in the
Department of Natural Medicinal Chemistry, China Pharmaceutical Univer-
sity.
2857 cmꢀ1), carbonyl (1736 cmꢀ1), and phenyl (1631 cmꢀ1)
groups. Alkline hydrolysis of 3 afforded decanoic acid, dode-
noic acid, trans-cinnamic and simonic acid B. From 1H-, 13C-
Extraction and Isolation Roots (18 kg) of I. batatas were pulverized
and dried in the shade for one week, and were extracted with 95% EtOH
NMR, HMQC, and TOCSY (Table 2), signals were assigned

December 2008
1673
Fig. 5. Structures of 6—8 and DdRS Values of the MPA Esters
(3ꢆ20 lꢆ2 h) at 80 °C, concentrated under a vacuum, and stood overnight. (tR 14.020 min): m/z [M]ꢂ 215 (23), 171 (31), 143 (55), 87 (85), 74 (100),
The solution was further concentrated to produce a residue, which was parti- 55 (86), 43 (96), 41 (56) from 3; 2-methylbutyric acid methyl ester (tR
tioned with CHCl3 (5ꢆ0.5 l) and water (0.5 l) to give 45 g and 18 g of ex- 3.593 min): m/z [MꢂH]ꢂ 117 (5), 101 (23), 88 (87), 57 (100), 41 (57) from
tract, respectively. The CHCl3 extract was subjected to silica column chro- 1 and 2. The 2-methylbutyric acid prepared from the crude resin glycoside
matography (F5ꢆ60 cm, 200—300 mesh, 300 g), eluted with CHCl3–
MeOH (100 : 3→100 : 50). Fractions of 245 to 272 (1.8 g) eluted with
CHCl3–MeOH (100 : 10) was further submitted to Rp-C18 column chro-
matography (F1.5ꢆ30, 40 g) and eluted with MeOH–H2O (90 : 10→100 : 0)
to afford fraction 1 by 90 : 10 MeOH/H2O, fraction 2 by 95 : 5 MeOH/H2O
was proved S-configuration by comparing the optical rotation with that of
authentic (S)-2-methylbutyric acid ([a]D25 ꢂ19.0°).
Acid Hydrolysis The ether-insoluble layer of alkaline hydrolysis was
extracted with n-BuOH (30.0 ml) to afford 4, which was methylated with
CH3OH/0.5 N H2SO4 to give 5 (simonic acid B methyl ester). Compound 5
and fraction 3 by MeOH, respectively. Fraction 1 was further purified by was hydrolyzed with 1 N H2SO4, then the product was extracted with ether
successive Rp-18 preparative HPLC (UV detection at 210 and 280 nm) with (30.0 ml) to yield 6 (11-hydroxyhexadecanoic acid methyl ester) and ex-
80% MeOH/H2O to afford batatoside IV (2, 45 mg, tR 8.34 min), and 90%
MeOH/H2O to afford batatoside III (1, 4.1 mg, tR 6.43 min) and batatoside V
(3, 3.4 mg, tR 10.16 min), respectively.
tracted with BuOH to afford mixture of saccharides. The solution of (R)-
MPA (12.0 mg, MPAꢁmethyloxyphenylacetic acid) and DMAP (10.0 mg,
DMAPꢁ4-dimethylaminopyridine) in CH2Cl2 (1.0 ml) was added to CH2Cl2
Batatoside III (1): White amorphous power, [a]D25 ꢀ18.7° (cꢁ0.4, (1.5 ml) containing 6 (2.0 mg), followed by DCC (10.0 mg, DCCꢁN,N-dicy-
MeOH). IR nmax (KBr) 3445, 2933, 2859, 1723, 1636 cmꢀ1; UV (MeOH)
clohexylcarbodiimide), and the solution was stirred for 17.0 h at 25.0 °C.
lmax (log e): 280 (4.33), 217 (4.25), 204 (4.28) nm. H- (600 MHz, C5D5N)
Then EtOAc (30.0 ml) was added to quench the reaction and filtrated.2) The
1
and 13C-NMR (150 MHz, C5D5N) see Table 1. ESI-MS 1281 [MꢀH]ꢀ; HR- filtrate was concentrated and purified by silica gel chromatography eluted
ESI-MS 1305.6627 [MꢂNa]ꢂ (C65H102O25Na, Calcd 1305.6602).
with cyclohexane/ethyl acetate (95 : 5) to give 7 (2.6 mg, 94%, 11-(R-MPA)-
Batatoside IV (2): White amorphous power, [a]D25 ꢀ38.1° (cꢁ0.5, hexadecanoic acid methyl ester) (Fig. 5). Treatment of 6 with (S)-MPA by
MeOH). IR nmax (KBr) 3448, 2929, 2856, 1736, 1636 cmꢀ1; 1H- (600 MHz,
C5D5N) and 13C-NMR (150 MHz, C5D5N) see Table 1. ESI-MS m/z 1067
the same procedure yielded 8 (2.3 mg, 85%, 11-(S-MPA)-hexadecanoic acid
methylester). The sbustituents phenyl in R-MPA and S-MPA could shield
[MꢀH]ꢀ; HR-ESI-MS 1091.5616 [MꢂNa]ꢂ (C51H88O23Na, Calcd different sites, so the values in 7 and 8 were variance, which DdRS (DdRHS10ꢁ
1091.5608).
0.06, DdRHS12ꢁꢀ0.13, DdRHS16ꢁꢀ0.07 ppm)14—18) made it possible to assign
11S to 6, same as that in the literature.2) The mixture of saccharides was neu-
tralized by passing through an ion-exchange resin (Amberlite MB-3) column
Batatoside V (3): White amorphous power, [a]D25 ꢀ28.1° (cꢁ0.5, MeOH).
IR nmax (KBr) 3443, 2929, 2857, 1736, 1631 cmꢀ1; UV (MeOH) lmax (log e):
280 (4.18), 217 (4.07), 204 (4.06) nm. 1H- (600 MHz, C5D5N) and 13C-NMR and concentrated to yield saccharides residue, which was treated with water
(150 MHz, C5D5N) see Table 2. ESI-MS m/z 1450 [Mꢀ H]ꢀ; HR-ESI-MS (0.05 ml) and pyridine (0.03 ml) at 60 °C for 1 h under stirring. After the sol-
1473.8423 [MꢂNa]ꢂ (C77H126O25Na, Calcd 1473.8480).
vent was evaporated and the reaction mixture was dried, pyridine (0.5 ml),
Alkaline Hydrolysis of 1—3 Compounds 1—3 (3 mg each) in 5% KOH hexamethyldisilazane (0.8 ml), and trimethylsilyl chloride (0.4 ml) were
(3 ml) were refluxed at 90 °C for 2 h, separately. The reaction mixtures were added to the residue. The reaction mixture was heated at 60 °C for 30 min.
acidified to pH 4 and extracted with ether (30 ml) and n-BuOH (30 ml). The
ether layer was washed with H2O, dried over anhydrous Na2SO4, and evapo-
rated under reduced pressure. The residue was methylated with CH3OH/
0.5 N H2SO4 to afford methyl ester, which was analyzed by GC-MS (Varian
3800 GC, Varian 2200 MS, 70 eV) under the following conditions: capillary
column, SE-30 (30 mꢆ0.25 mmꢆ0.25 mm); column temperature, 160—250 °C
temperature programmed at with of 5 °C/min; carrier gas, N2 (30 ml/min).
Under the same condition as above, the supernatant was applied to GC-MS
to afford D-fucose [tR 4.57 min, [a]D25 ꢂ66.4° (cꢁ0.8, H2O)], L-rhamnose [tR
5.09 min, [a]D25 ꢀ9.7° (cꢁ1.0, H2O)].
Simonic Acid B (4) White amorphous power, [a]D25 ꢀ82.0° (cꢁ0.8,
1
MeOH). IR nmax (KBr) 3425, 2931, 2858, 1713, 1043 cmꢀ1. H- (600 MHz,
C5D5N) and 13C-NMR (150 MHz, C5D5N) see Table 2. ESI-MS m/z: 1001
[MꢀH]ꢀ, 855 [MꢀHꢀ146]ꢀ, 709 [855ꢀ146]ꢀ, 563 [709ꢀ146]ꢀ, 417
Five different peaks were detected from compounds 1—3 and identified by [563ꢀ146]ꢀ, 271 [417ꢀ146]ꢀ.
comparing with authentic samples as trans-cinnamoic acid methyl ester (tR
11-Hydroxyhexadecanoic Acid Methyl Ester (6): Colorless oil (CHCl3),
12.498 min): m/z [M]ꢂ 162 (45), 131 (100), 103 (76), 77 (35) from 1 and 3; [a]D25 ꢂ1.1° (cꢁ0.2, CHCl3); IR nmax (KBr): 3333, 2920, 2850, 1207 cmꢀ1
;
n-decanoic acid methyl ester (tR 11.422 min): m/z [M]ꢂ 116 (10), 143 (45),
1H-NMR (600 MHz, CDCl3) dH: 3.67 (s, OCH3), 3.58 (m, OCH-11), 2.30 (t,
87 (64), 74 (100), 55 (55), 43 (80) and n-dodecanoic acid methyl ester Jꢁ7.5 Hz, OCOCH2-2), 1.62 (t, Jꢁ7.0 Hz, CH2-10), 1.44 (m, CH2-12), 0.89

1674
Vol. 56, No. 12
(t, Jꢁ6.9 Hz, CH3-16); TOF-MS m/z: 309 [MꢂNa]ꢂ.
5) Barnes C. C., Smalley M. K., Manfredi K. P., Kindscher K., Loring H.,
Sheeley D. M., J. Nat. Prod., 66, 1457—1462 (2003).
6) Rajapakse S., Nilmagoda S. D., Molnar M., Ballard R. E., Austin D. F.,
Bohac J. R., Mol. Phylogenet. Evol., 30, 623—632 (2004).
7) The Editorial Committee of the Administration Bureau of Flora of
China, “Flora of China (Zhongguo Zhiwuzhi),” Vol. 64, Beijing Sci-
ence & Technology Press, Beijing, 2005, p. 88.
8) Li S. Z. (Min dynasty), “Compendium of Materia Medica,” (midst vol-
umn), p. 1501.
9) Escalante-Sanchez E., Pereda-Miranda R., J. Nat. Prod., 70, 1029—
1034 (2007).
11-(R-MPA)-hydroxyhexadecanoic Acid Methyl Ester (7): Colorless oil
(CHCl3), [a]D25 ꢀ2.0° (cꢁ0.1, CHCl3); IR nmax (KBr): 3442, 2927, 2855,
1743, 1261, 802 cmꢀ1 1H-NMR (600 MHz, CDCl3) dH: 7.44 (m, C6H2),
;
7.34 (m, C6H3), 4.90 (m, OCH-11), 4.73 (s, OCH), 3.67 (s, OCH3), 3.41 (t,
Jꢁ1.7 Hz, 1-OCH3), 2.30 (t, Jꢁ7.4 Hz, OCOCH2-2), 1.67 (m, CH2-10), 1.41
(m, CH2-12), 0.77 (3H, Jꢁ7.1 Hz, CH3-16); TOF-MS m/z: 457 [MꢂNa]ꢂ;
435 [MꢂH]ꢂ.
11-(S-MPA)-hydroxyhexadecanoic Acid Methyl Ester (8): Colorless oil
(CHCl3), [a]D25 ꢂ1.4° (cꢁ0.2, CHCl3); IR nmax (KBr): 3453, 2961, 2926,
1
2852, 1742, 1261 cmꢀ1; H-NMR (600 MHz, CDCl3) dH: 7.44 (m, C6H2),
10) Yin Y. Q., Kong L. Y., J. Asian Nat. Prod. Res., 10, 233—238 (2008).
11) Yin Y. Q., Li Y., Kong L. Y., J. Agric. Food Chem., 56, 2363—2368
(2008).
7.34 (m, C6H3), 4.90 (m, OCH-11), 4.73 (s, OCH), 3.67 (s, OCH3), 3.41 (t,
Jꢁ1.7 Hz, 1-OCH3), 2.30 (t, Jꢁ7.6 Hz, OCOCH2-2), 1.61 (m, CH2-10), 1.54
(m, CH2-12), 0.84 (t, Jꢁ7.1 Hz, CH3-16); TOF-MS m/z: 457 [MꢂNa]ꢂ.
12) Noda N., Yoda S., Kawasaki T., Miyahata K., Chem. Pharm. Bull., 40,
3163—3168 (1992).
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Acknowledgment This work was supported by the National Natural
Science Foundation of China (No. 30472144) and the Cultivation Fund of
the Key Scientific and Technical Innovation Project, Ministry of Education
of China (707033).
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