Components of ether-insoluble resin glycoside (convolvulin) from seeds of Quamoclit pennata

Article abstract of DOI:10.1248/cpb.58.666

Alkaline hydrolysis of the ether-insoluble resin glycoside (convolvulin) fraction of the seeds of Quamoclit pennata BOJER (Convolvulaceae) provided five new glycosidic acids, quamoclinic acids B, C, D, E, and F, along with six organic acids, isobutyric, 2

Full text of DOI:10.1248/cpb.58.666

666
Regular Article
Chem. Pharm. Bull. 58(5) 666—672 (2010)
Vol. 58, No. 5
Components of Ether-Insoluble Resin Glycoside (Convolvulin) from Seeds
of Quamoclit pennata
Masateru ONO, ,a Yo ko T AKAGI-TAKI,b Fumiko HONDA-YAMADA,b Naoki NODA,b and
*
b
Kazumoto MIYAHARA
a School of Agriculture, Tokai University; 5435 Minamiaso, Aso, Kumamoto 869–1404, Japan: and b Faculty of
Pharmaceutical Sciences, Setsunan University; 45–1 Nagaotoge-cho, Hirakata, Osaka 573–0101, Japan.
Received December 22, 2009; accepted February 4, 2010; published online March 4, 2010
Alkaline hydrolysis of the ether-insoluble resin glycoside (convolvulin) fraction of the seeds of Quamoclit
pennata BOJER (Convolvulaceae) provided five new glycosidic acids, quamoclinic acids B, C, D, E, and F, along
with six organic acids, isobutyric, 2S-methylbutyric, tiglic, 2R,3R-nilic, 7S-hydroxydecanoic, and 7S-hydroxydo-
decanoic acids. These new compounds were characterized on the basis of spectroscopic data as well as chemical
evidence. Quamoclinic acids E and F are the first examples of heptaglycosides of glycosidic acid.
Key words resin glycoside; convolvulin; Quamoclit pennata; Convolvulaceae; glycosidic acid; organic acid
The so-called resin glycosides are well known as purgative
ingredients, which are characteristic of some crude drugs
such as Mexican Scammony Root, Orizaba Root, Jalapae
Tuber, Pharbitidis Semen, and Rhizoma Jalapae Braziliensis.
These drugs all originate from Convolvulaceae plants and
can be roughly divided into an ether-soluble resin glycoside
called jalapin and an ether-insoluble resin glycoside called
convolvulin.1) In a previous paper,2) we reported the isolation
and structural elucidation of a new glycosidic acid called
quamoclinic acid A that was obtained along with three or-
ganic acids, 2S-methylbutyric, n-decanoic, and n-dodecanoic
acids, upon alkaline hydrolysis of the jalapin fraction of the
seeds of Quamoclit pennata BOJER. Further, we isolated four
genuine jalapins, quamoclins I, II, III, and IV, from the frac-
tion.2) This paper deals with the component organic and gly-
cosidic acids of the convolvulin fraction of the seeds of this
plant.
The alkaline hydrolysis products of the convolvulin frac-
tion previously obtained2) were fractionated into organic acid
and glycosidic acid fractions. Gas chromatography (GC) of
the former revealed the presence of isobutyric, 2-methyl-
butyric, and tiglic acids. Further, the organic acid fraction
was methylated with diazomethane-ether and then ex-
amined using GC; it exhibited four peaks assignable to
methyl tiglate, methyl nilate, methyl 7-hydroxydecanoate,
and methyl 7-hydroxydodecanoate.
The organic acid fraction was acylated with p-bro-
mophenacyl bromide followed by chromatographic separa-
Fig. 1. Structures of 1—11, 3a—11a, 4b, 4c, 5b, 5c, and 8b
tion to give p-bromophenacyl 2-methylbutyrate (1), p-bro-
mophenacyl tiglate (2), p-bromophenacyl nilate (3), p-bro- methylphenylacetic acid (MTPA) esters4) (3a from 3; 3ꢀa
mophenacyl 7-hydroxydecanoate (4), and p-bromophenacyl from 3ꢀ), and it was confirmed that 3 did not contain its
7-hydroxydodecanoate (5) (Fig. 1). The absolute configura- enantiomer, while 3ꢀ was a mixture of p-bromphenacyl esters
tion of 1 was defined as S by comparison of the specific rota- of the 2R,3R- and the 2S,3S-nilic acid in the ratio of approxi-
tion with an authentic sample,3) and that of 3 was considered mately 6 : 5 on the basis of the ratio of intensities of signals
to be 2R,3R by comparisons of the specific rotation and the due to H3-5 of the (2R,3R)-form and that of the (2S,3S)-form.
1H-NMR spectrum of 3 with those of an authentic sample.3)
The alkaline hydrolysis of 4 and of 5, with subsequent dia-
However, the absolute value of the specific rotation of 3 was zomethane–ether treatment, gave methyl 7-hydroxydecanoate
approximately 6-fold greater than that of p-bromophenacyl (4a) and methyl 7-hydroxydodecanoate (5a), respectively.
nilate (3ꢀ) previously obtained in a similar process as that The configurations at C-7 of 4a and 5a were determined
used for 3 from the convolvulin fraction of Pharbitidis using Mosher’s method.4) Compounds 4a and 5a were con-
Semen.3) Thus the optical purities of 3 and 3ꢀ were examined verted into the corresponding (ꢁ)-MTPA esters (4b from 4a;
1
using their H-NMR spectra of (ꢁ)-a-methoxy-a-trifluoro- 5b from 5a) and (ꢂ)-MTPA esters (4c from 4a; 5c from 5a).
© 2010 Pharmaceutical Society of Japan
∗ To whom correspondence should be addressed. e-mail: mono@agri.u-tokai.ac.jp

May 2010
667
1
Comparison of the H-NMR spectrum of 4b with that of 4c
revealed chemical shift differences [Dd(d4bꢁd4c)] at the
terminal methyl group and 2-methylene group of ꢁ0.067 and
ꢂ0.042 ppm, respectively, and the differences [Dd(d5bꢁ
d5c)] were observed as ꢁ0.036 and ꢂ0.042 ppm in regard to
H3-12 and H2-2, respectively; these results suggested that
both configurations at C-7 of 4a and 5a were S (Fig. 1).5)
Acidic hydrolysis of the glycosidic acid fraction gave agly-
cone and monosaccharide fractions. Methylation of the for-
mer with diazomethane–ether yielded methyl 7S-hydroxy-
decanoate (4a) and methyl 3S,11S-dihydroxytetradecanoate
(methyl ipurolate) (6),3) which were identified by their 13C-
NMR spectral data and 1H-NMR spectral data of (ꢁ)-MTPA
esters.5) The sugar fraction was converted into trimethylsilyl
ethers of diastereomeric thiazolidine derivatives and then an-
alyzed using GC, according to the process reported by Hara
et al.6) Derivatives of D-glucose, D-fucose, D-quinovose, and
L-rhamnose were detected.
Fig. 2. Fragment Ions Observed in the Negative-Ion FAB-MS of 8a and
10a
The glycosidic acid fraction was roughly separated into
two fractions (fr. 7 and 8) using silica gel column chromatog-
raphy. Fr. 7 was derived into a methyl ester with dia-
zomethane–ether, and subsequent chromatography separation and two mol each of D-glucose and D-quinovose. The cou-
afforded a methyl ester (7) of glycosidic acid. Acidic hydrol- pling constants of signals due to anomeric and methine pro-
ysis of 7 gave 7-hydroxydecanoic acid and D-quinovose. tons together with JC-1–H-1 values due to the sugar moiety in-
Saponification of 7 yielded a new glycosidic acid, quamo- dicated that all the monosaccharide units were of the pyra-
clinic acid B (7a), which showed an [MꢁH]ꢁ ion peak at m/z nose type, and further, that the mode of glycosidic linkage of
1
333 (C16H29O7) along with a fragment ion peak at m/z 187 the rhamnose unit was a in a C4 conformation and those of
4
[333ꢁ146 (6-deoxyhexose unit)]ꢁ in the negative-ion FAB- the glucose, quinovose, and fucose units were b in C1 con-
MS. The 13C-NMR spectrum of 7a indicated signals due to formations. The 13C-NMR signals due to the sugar moiety of
16 carbons comprising one carbonyl carbon, one oxygenated 8a were compared with those of methyl pyranosides in the
methine carbon, and one terminal quinovopyranosyl unit.7) literature.7,8) The glycosylation shifts8,9) were observed at C-2
1
Further, the H-NMR spectrum of 7a showed signals due to (ꢂ6.6 ppm) of the fucose unit (Fuc), C-2 (ꢂ2.8 ppm) of the
two equivalent methylene protons adjacent to a carbonyl first glucose unit (Glc), C-2 (ꢂ9.8 ppm) of the second glu-
group, and a primary methyl group ascribable to the 7-hy- cose unit (Glcꢀ), and C-3 (ꢂ6.5 ppm) and C-4 (ꢂ5.6 ppm) of
droxydecanoic acid moiety along with one b-D-quinovopyra- the rhamnose unit (Rha). The 13C-NMR signals assignable to
4
nosyl unit having the C1 conformation. Consequently, the C-11 of the aglycone moiety (Ag) showed a downfield shift
structure of 7a was defined as 7S-hydroxydecanoic acid 7-O- of 9.4 ppm when compared with that of methyl ipurolate.3)
b-D-quinovopyranoside (Fig. 1).
These data suggest that the sugar linkages of 8a were located
Fr. 8 was acylated with phenacyl bromide followed by sep- at OH-2 of Fuc, OH-2 of Glc, OH-2 of Glcꢀ, OH-3 and OH-4
aration to give four phenacyl esters (8—11) of glycosidic of Rha, and OH-11 of Ag. To determine the sequence of the
acids. On alkaline hydrolysis, 8—11 gave free glycosidic sugar moiety, the nuclear Overhauser and exchange spec-
acids, quamoclinic acids C (8a), D (9a), E (10a), and F troscopy (NOESY) spectra of 8a and peracetate (8b) of 8
(11a), respectively.
were recorded. Five of the cross peaks observed in the
On acidic hydrolysis, quamoclinic acid C (8a) gave NOESY spectrum of 8a were assigned as those between H-1
ipurolic acid, D-glucose, D-fucose, D-quinovose, and L-rham- of Glc and H-2 of Fuc, H-1 of Rha and H-2 of Glc, H-1 of
nose. The negative-ion FAB-MS of 8a showed an [MꢁH]ꢁ Glcꢀ and H-3 of Rha, H-1 of Qui and H-4 of Rha, and H-1 of
ion peak at m/z 1167 along with fragment ion peaks at m/z Quiꢀ and H-2 of Glcꢀ, while the counterpart due to H-1 of
1021 [1167ꢁ146]ꢁ, 859 [1021ꢁ162 (hexose unit)]ꢁ, 713 Fuc could not be defined because the signals were overlap-
[859ꢁ146]ꢁ, 567 [859ꢁ2ꢃ146]ꢁ, and 405 [567ꢁ162]ꢁ ping. The NOESY spectrum of 8b showed cross peaks that
(Fig. 2). The 13C-NMR spectrum of 8a exhibited signals due were assigned as in between H-1 of Fuc and H-11 of Ag, H-1
1
to six anomeric carbons and one carbonyl carbon. In the H- of Glc and H-2 of Fuc, and H-1 of Glcꢀ and H-3 of Rha.
NMR spectrum of 8a, signals due to six anomeric protons,
Accordingly, the structure of 8a was characterized as
four secondary methyl groups assignable to H3-6 of 6-deoxy- (3S,11S)-ipurolic acid 11-O-b-D-quinovopyranosyl-(1→2)-
hexose units, as well as two nonequivalent methylene protons O-b-D-glucopyranosyl-(1→3)-[O-b-D-quinovopyranosyl-
adjacent to a carbonyl group, and one primary methyl group (1→4)]-O-a-L-rhamnopyranosyl-(1→2)-O-b-D-glucopyra-
ascribable to the ipurolic acid moiety were observed. The nosyl-(1→2)-b-D-fucopyranoside (Fig. 1).
NMR signals due to the sugar moiety were assigned with the
Acidic hydrolysis of quamoclinic acid D (9a) afforded
1
1
aid of H–1H correlation spectroscopy (COSY) and H–13C ipurolic acid, D-glucose, D-fucose, D-quinovose, and L-rham-
heteronuclear shift-correlated 2D-NMR (HETCOR) spectra nose, which were the same products as derived from the
(Tables 1 and 2); these data suggested that 8a was composed acidic hydrolysis of 8a. Further, the negative-ion FAB-MS of
of one mol each of ipurolic acid, D-fucose, and L-rhamnose, 9a was superimposable on that of 8a, in which an [MꢁH]ꢁ

668
Vol. 58, No. 5
Table 1. 1H-NMR Spectral Data for 8a, 8b and 9a (in Pyridine-d5,
600 MHz)
and C-4 (ꢂ5.5 ppm) of Rha, and C-2 (ꢂ9.9 ppm) of Glcꢀ.
Moreover, the NOESY spectrum of 9a showed six cross
peaks between H-1 of Fuc and H-11 of Ag, H-1 of Glc and
H-2 of Fuc, H-1 of Rha and H-2 of Glc, H-1 of Glcꢀ and H-3
of Rha, H-1 of the second fucose unit (Fucꢀ) and H-4 of Rha,
and H-1 of Quiꢀ and H-2 of Glcꢀ.
Consequently, the structure of 9a was concluded to be
(3S,11S)-ipurolic acid 11-O-b-D-quinovopyranosyl-(1→2)-
O-b -D-glucopyranosyl-(1→3)-[O-b -D-fucopyranosyl-
(1→4)]-O-a-L-rhamnopyranosyl-(1→2)-O-b-D-glucopyra-
nosyl-(1→2)-b-D-fucopyranoside (Fig. 1), which was an
epimer of 8a with replacement of the b-D-quinovopyranosyl
group attached to OH-4 of Rha by the b-D-fucopyranosyl
group.
8a
Fuc-1 4.78 d (7.0)
8b
9a
4.84 d (7.5)
4.71 d (6.5)
2
3
4
5
6
4.46 dd (7.0, 9.5)
4.49 dd (3.5, 9.5)
ca. 4.10
3.87 q (6.5)
1.39 d (6.5)
4.45 dd (7.5, 9.5) ca. 4.41
5.45 dd (3.5, 9.5) ca. 4.41
5.76 d (3.5)
ca. 4.53
4.06 d (3.0)
3.72 q (6.5)
1.37 d (6.5)
5.52 d (7.5)
1.50 d (6.5)
ca. 5.32
Glc-1 5.60 d (7.5)
2
3
4
5
6
4.19 dd (7.5, 9.0)
4.13 dd (9.0, 9.0)
4.03 dd (9.0, 9.0)
3.63 ddd (2.5, 5.5, 9.0) 3.97 m
4.30 dd (2.5, 11.5)
4.17 dd (5.5, 11.5)
4.22 dd (8.0, 9.5) 4.17 dd (7.5, 9.0)
5.69 dd (9.5, 9.5) 4.11 dd (9.0, 9.0)
5.35 dd (9.5, 9.5) 4.03 dd (9.0, 9.0)
3.63 ddd (3.5, 6.0, 9.0)
4.31 dd (3.5, 11.5)
4.18 dd (6.0, 11.5)
6.28 d (2.0)
ca. 4.53
ca. 4.26
5.46 s
On acidic hydrolysis, quamoclinic acid E (10a) gave the
same products as those of 8a and 9a. In the negative-ion
FAB-MS, 10a exhibited an [MꢁH]ꢁ ion peak at m/z 1313,
which was 146 mass units larger than that of 9a, and frag-
ment ion peaks at m/z 1167 [1313ꢁ146]ꢁ, 1021 [1167ꢁ
146]ꢁ, 859 [1021ꢁ162]ꢁ, 713 [859ꢁ146]ꢁ, 567 [713ꢁ
146]ꢁ, and 405 [567ꢁ162]ꢁ (Fig. 2). The 1H-NMR spectrum
of 10a indicated signals due to seven anomeric protons, five
secondary methyl groups, two nonequivalent methylene pro-
tons, and one primary methyl group. The 13C-NMR spectrum
of 10a showed signals due to seven anomeric carbons and
Rha-1 6.31 d (2.0)
2
3
4
5
6
4.93 dd (2.0, 3.0)
ca. 5.64
ca. 4.54
4.95 dd (2.0, 3.0)
5.17 dd (3.0, 9.5)
5.18 dd (3.0, 9.5)
4.69 dd (9.5, 9.5)
5.05 dq (9.5, 6.0)
1.92 d (6.0)
4.29 dd (9.5, 9.5) 4.70 dd (9.5, 9.5)
4.71 dq (9.5, 6.0) 4.99 dq (9.5, 6.0)
1.83 d (6.0)
5.49 d (7.5)
ca. 4.27
5.57 dd (9.5, 9.5) ca. 4.41
5.29 dd (9.5, 9.5) 4.13 dd (9.0, 9.0)
ca. 4.29
1.90 d (6.0)
5.99 d (8.0)
4.00 dd (8.0, 9.0)
Glcꢀ-1 5.99 d (7.5)
2
3
4
5
6
ca. 3.97
4.38 dd (9.0, 9.0)
ca. 4.10
ca. 3.98
4.45 dd (2.5, 11.5)
4.17 dd (5.5, 11.5)
3.98 ddd (2.5, 6.0, 9.0)
4.49 dd (6.0, 11.5) 4.44 dd (2.5, 11.5)
4.43 dd (2.5, 11.5) 4.18 dd (6.0, 11.5)
ca. 5.22
1
one carbonyl carbon. These H- and 13C-NMR signals were
Qui-1 5.76 d (7.5)
assigned with the aid of techniques similar to those used for
8a, and the data indicated that 10a was composed of three
mol of fucopyranose, two mol of glucopyranose, and one mol
each of rhamnopyranose, quinovopyranose, and ipurolic acid.
The mode of their glycosidic linkages was elucidated from
the coupling constants of signals due to anomeric and me-
thine protons as well as JC-1–H-1 values due to the sugar moi-
ety, as shown in Fig. 1. In the 13C-NMR spectral data of 10a,
glycosylation shifts were observed at C-2 (ꢂ7.0 ppm) of Fuc,
C-2 (ꢂ3.8 ppm) of Glc, C-3 (ꢂ6.5 ppm) and C-4 (ꢂ5.6 ppm)
of Rha, C-2 (ꢂ10.2 ppm) of Glcꢀ, C-3 (ꢂ9.4 ppm) of Quiꢀ,
and C-11 (ꢂ9.4 ppm) of Ag. From these data, it was assumed
that on 10a one additional b-D-fucopyranosyl unit may be
attached to OH-3 of Quiꢀ of 9a. This assumption was con-
firmed by the appearance of seven cross peaks between H-1
of Fuc and H-11 of Ag, H-1 of Glc and H-2 of Fuc, H-1 of
Rha and H-2 of Glc, H-1 of Glcꢀ and H-3 of Rha, H-1 of
Fucꢀ and H-4 of Rha, H-1 of Quiꢀ and H-2 of Glcꢀ, and H-1
of the third fucose (Fucꢄ) and H-3 of Quiꢀ in the NOESY
spectrum of 10a.
2
3
4
5
3.94 dd (7.5, 9.0)
ca. 5.60
ca. 5.60
ca. 5.63
ca. 3.94
4.26 dd (9.0, 9.0)
3.67 dd (9.0, 9.0)
ca. 4.00
6
1.57 d (6.0)
1.46 d (6.0)
Fucꢀ-1
5.66 d (7.5)
2
3
4
5
6
4.28 dd (7.5, 9.5)
4.25 dd (3.0, 9.5)
3.96 dd (1.0, 3.0)
ca. 4.08
1.50 d (6.5)
5.11 d (7.5)
Quiꢀ-1 5.09 d (8.0)
5.62 d (7.5)
2
3
4
5
6
ca. 4.10
ca. 3.97
3.67 dd (9.0, 9.0)
3.70 dq (9.0, 6.0)
1.64 d (6.0)
5.52 dd (7.5, 9.5) 4.09 dd (7.5, 9.0)
5.72 dd (9.5, 9.5) 4.01 dd (9.0, 9.0)
5.19 dd (9.5, 9.5) 3.63 dd (9.0, 9.0)
4.08 dq (9.5, 6.0) 3.71 dq (9.0, 6.0)
1.38 d (6.0)
3.02 dd (7.5, 16.0) 2.89 dd (8.0, 15.0)
2.99 dd (5.0, 16.0) 2.86 dd (5.0, 15.0)
ca. 5.67
ca. 3.93
0.92 t (7.0)
1.63 d (6.0)
Ag-2 2.88 dd (8.0, 15.0)
2.85 dd (5.0, 15.0)
3
4.53 m
4.53 m
3.85 m
0.90 t (7.0)
11 ca. 3.86
14 0.89 t (7.0)
d in ppm from tetramethylsilane (TMS) (coupling constants (J) in Hz are given in
parentheses). Fuc, fucopyranosyl; Glc, glucopyranosyl; Rha, rhamnopyranosyl; Qui,
quinovopyranosyl; Ag, aglycone. 8b: d 2.38, 2.28, 2.27, 2.25, 2.23, 2.17, 2.15, 2.15,
2.11, 2.10, 2.09, 2.08, 2.06, 2.01, 2.01, 1.97 (all singlet, COCH3).
Thus the structure of 10a was determined to be (3S,11S)-
ipurolic acid 11-O-b-D-fucopyranosyl-(1→3)-O-b-D-quin-
ovopyranosyl-(1→2)-O-b-D-glucopyranosyl-(1→3)-[O-b-D-
fucopyranosyl-(1→4)]-O-a-L-rhamnopyranosyl-(1→2)-O-b-
and fragment ion peaks were seen at m/z 1167, 1021, 859, D-glucopyranosyl-(1→2)-b-D-fucopyranoside.
713, 567, and 405. The 1H- and 13C-NMR spectral data of 9a
On acidic hydrolysis, quamoclinic acid F (11a) liberated
indicated that it was composed of one mol each of ipurolic acid, D-glucose, D-quinovose, D-fucose, and L-rham-
quinovopyranose, rhamnopyranose, and ipurolic acid, and nose. The negative-ion FAB-MS of 11a was almost the same
two mol each of glucopyranose and fucopyranose. The data as that of 10a, in which an [MꢁH]ꢁ and fragment ion peaks
also indicated that the mode of glycosidic linkages of the were observed at m/z 1313, 1167, 1021, 859, 567, and 405.
glucose, quinovose, and fucose units are b in the 4C1 confor- The 1H- and 13C-NMR signals due to the sugar moiety of 11a
mations and that of the rhamnose unit is a in the 1C4 confor- suggested that 11a was composed of two mol each of glu-
mation. Glycosylation shifts in the 13C-NMR spectral data cose, quinovose, and rhamnose and one mol of fucose, which
of 9a were observed at C-11 (ꢂ9.3 ppm) of Ag, C-2 were all of the pyranose form, and further, the mode of gly-
(ꢂ7.0 ppm) of Fuc, C-2 (ꢂ3.4 ppm) of Glc, C-3 (ꢂ6.7 ppm) cosidic linkages of the glucose, quinovose, and fucose units

May 2010
669
Table 2. 13C-NMR Spectral Data for 8a—11a (in Pyridine-d5, 150 MHz)
8a
9a
10a
11a
8a
9a
10a
11a
Fuc-1
102.4
78.6
76.0
72.9
70.9
17.1
102.6
77.6
79.1
72.5
77.2
63.1
100.8
71.7
79.0
79.2
68.2
19.1
101.2
84.6
77.1
71.6
78.0
62.6
102.9
76.5
78.5
76.5
72.3
18.8
102.4
79.0
75.8
72.8
70.9
17.1
102.9
78.2
79.0
72.5
77.1
63.2
101.1
71.6
79.2
79.1
68.4
19.2
101.1
84.7
77.2
71.6
78.1
62.7
102.4
79.0
75.9
72.8
70.9
17.2
102.7
78.6
78.8
72.5
77.1
63.1
101.3
71.8
79.0
79.2
68.5
19.2
101.5
85.0
77.7
71.5
78.0
62.6
102.4
78.6
76.1
73.0
71.0
17.2
102.5
77.8
79.0
72.4
77.2
63.1
100.9
72.0
78.1
79.7
68.4
19.3
101.6
84.9
77.3
71.9
78.1
62.7
102.7
76.6
78.5
76.5
72.3
18.8
Fucꢀ-1
103.4
73.5
75.7
72.9
71.0
17.1
105.1
76.0
77.7
76.8
73.6
18.6
103.4
73.4
75.6
72.9
71.0
17.1
105.3
74.8
87.4
74.7
73.2
18.5
105.7
72.5
75.0
72.4
72.0
17.0
2
3
4
5
2
3
4
5
6
6
Glc-1
Quiꢀ-1
105.1
75.8
77.6
77.2
73.7
18.5
105.8
77.3
83.0
74.9
73.9
18.6
2
3
4
5
2
3
4
5
6
6
Rha-1
Fucꢄ-1
2
3
4
5
2
3
4
5
6
6
Glcꢀ-1
Rhaꢀ-1
102.6
72.3
72.6
74.0
69.8
18.7
175.2
44.0
68.6
80.1
14.5
2
3
4
5
2
3
4
5
6
6
Qui-1
Ag-1
2
3
11
14
175.3
43.9
68.5
80.0
14.5
175.2
43.9
68.5
79.9
14.5
175.2
43.9
68.6
80.0
14.5
2
3
4
5
6
d in ppm from TMS. Fuc, fucopyranosyl; Glc, glucopyranosyl; Rha, rhamnopyranosyl; Qui, quinovopyranosyl; Ag, aglycone.
4
Experimental
were b in the C1 1conformations and that of the rhamnose
All instruments and materials used were as cited in the preceding report10)
unless otherwise specified.
unit was a in the C4 conformation. The 13C-NMR spectral
data indicated glycosylation shifts at C-2 (ꢂ6.6 ppm) of Fuc,
C-2 (ꢂ3.0 ppm) of Glc, C-3 (ꢂ5.6 ppm) and C-4 (ꢂ6.1 ppm)
of Rha, C-2 (ꢂ10.1 ppm) of Glcꢀ, C-3 (ꢂ5.0 ppm) of Qui,
and C-11 (ꢂ9.5 ppm) of Ag. The arrangement of sugar link-
ages was determined using the NOESY spectrum of 11a, that
is, seven cross peaks between H-1 of Fuc and H-11 of Ag, H-
1 of Glc and H-2 of Fuc and/or H-1 of Glc and H-3 of Fuc,
H-1 of Rha and H-2 of Glc, H-1 of Glc’ and H-3 of Rha, H-1
of Qui and H-4 of Rha, H-1 of Quiꢀ and H-2 of Glcꢀ, and H-
1 of second rhamnose unit (Rhaꢀ) and H-3 of Quiꢀ were ob-
served.
Consequently, the structure of 11a was defined to be
(3S,11S)-ipurolic acid 11-O-a-L-rhamnopyranosyl-(1→3)-O-
b-D-quinovopyranosyl-(1→2)-O-b-D-glucopyranosyl-(1→3)-
[O-b-D-quinovopyranosyl-(1→4)]-O-a-L-rhamnopyranosyl-
(1→2)-O-b-D-glucopyranosyl-(1→2)-b-D-fucopyranoside,
on which one mol of rhamnopyranose unit was bonded to
OH-3 of Qui of 8a.
Alkaline Hydrolysis of the Convolvulin Fraction The convolvulin
fraction (5.01 g) previously obtained2) was dissolved in 1 M KOH (30 ml) and
heated at 95 °C for 1.5 h. After cooling, the reaction mixture was adjusted to
pH 4.0 with 1 M HCl and shaken with ether (50 mlꢃ3). The ether layer was
dried over MgSO4 and evaporated in vacuo to give an oil (organic acid frac-
tion, 0.70 g). The H2O layer was chromatographed over MCI gel CHP20
(solvent, H2O→acetone). The acetone eluate was evaporated to dryness to
afford a white powder (4.29 g, glycosidic acid fraction).
Identification of Organic Acids An aliquot of the organic acid fraction
was analyzed using GC [column, 3.2 mm i.d.ꢃ2.0 m glass column packed
with Unisole 30T (5%); carrier gas N2, 1.5 kg/cm2; column temperature,
120 °C; retention times (tR) (min): 1.72 (isobutyric acid), 2.72 (2-methylbu-
tyric acid), 6.10 (tiglic acid)]. A small portion of the organic acid fraction
was methylated with diazomethane-ether and then analyzed using GC [col-
umn, 3.2 mm i.d.ꢃ2.0 m glass column packed with Unisole 30T (5%); car-
rier gas N2, 1.0 kg/cm2; column temperature, 60 °C for 3 min then elevated to
110 °C by 10 °C/min; tR (min): 2.61 (methyl tiglate), 8.60 (methyl nilate);
column, 3.2 mm i.d.ꢃ2.0 m glass column packed with Silicone OV-17 Uni-
port HP 80/100; carrier gas N2, 1.25 kg/cm2; column temperature, elevated
from 140 °C to 190 °C by 2 °C/min; tR (min): 4.39 (methyl 7-hydroxyde-
canoate), 8.99 (methyl 7-hydroxydodecanoate)].
The organic acid fraction (0.65 g) in dry acetone (30 ml) was neutralized
with triethylamine. p-Bromophenacylbromide (1.12 g) was added and the
mixture was left to stand at room temperature for 1 h and then concentrated
in vacuo to give a residue. The residue was fractionated between H2O
(25 ml) and ether (25 mlꢃ3). The ether layer was dried over MgSO4 and
evaporated in vacuo to give a residue. The residue was chromatographed
over a silica gel column [solvent, n-hexane–AcOEt (9 : 1→5 : 1→3 : 1→
2 : 1→1 : 1→0 : 1)→MeOH] to afford fr. 1 (538 mg), fr. 2 (20 mg), fr. 3
(15 mg), fr. 4 (64 mg), p-bromophenacyl nilate (3, 102 mg), fr. 5 (11 mg),
and fr. 6 (344 mg). Fr. 1 (247 mg) was subjected to HPLC [column, Kusano
C.I.G. Si, 22 mm i.d.ꢃ10 cm; solvent, n-hexane–AcOEt (60 : 1)] to give
p-bromophenacyl 2-methylbutyrate (1, 12 mg) and p-bromophenacyl tiglate
As the components of the convolvulin fraction of Q. pen-
nata BOJER, five new glycosidic acids, quamocilnic acids B,
C, D, E, and F, and six organic acids, isobutyric, 2S-methyl-
butyric, tiglic, 2R,3R-nilic, 7S-hydroxydecanoic, and 7S-hy-
droxydodecanoic acids, were elucidated. These components
were different from those of the jalapin fraction of this seed,
except for 2S-methylbutyric acid. Further, quamoclinic acids
E and F are the first examples of heptaglycosides of glyco-
sidic acid.

670
Vol. 58, No. 5
(2, 133 mg). HPLC of fr. 3 (15 mg) and fr. 4 (64 mg) on the Kusano C.I.G. Si
[column, 2.2 cm i.d.ꢃ10 cm; solvent, n-hexane–AcOEt (3 : 1)] furnished
(6 : 2 : 3) top layerꢂpyridine (1); rate of flow (Rf ): 0.39 (glucose), 0.53 (fu-
cose), 0.63 (rhamnose and/or quinovose)]. The sugar fraction (64 mg) was
subjected to GC-analysis as the trimethylsilyl ethers of the thiazolidine de-
rivatives, according to the process reported by Hara et al.6) GC [condition 2:
Hitachi G-3000 gas gaschromatograph equipped with 30 : 1 splitter and
flame-ionizing detector; column, fused silica capillary column Bonded
MPS-50 (Quadrex), 50 mꢃ0.25 mm, 0.25 mm film thickness; carrier gas, He
(30 ml/min); column temperature, 220 °C; tR (min): 18.57 (D-quinovose de-
rivative), 19.43 (L-rhamnose derivative), 21.10 (D-fucose derivative), 27.19
(D-glucose derivative)].
Preparation of (ꢀ)-MTPA Esters of 3, 3ꢁ, 4a, 5a, and 6 Freshly pre-
pared (ꢁ)-MTPACl (15 mg) was added to individual solutions of 3 (3 mg),
3ꢀ (4 mg), and 4a (2 mg) obtained from the organic acid fraction, 4a (2 mg)
obtained from the glycosidic acid fraction, 5a (1 mg), and 6 (3 mg) in pyri-
dine (0.5 ml) and CCl4 (5 drops) and left to stand at room temperature
overnight. The solvent was removed under an N2 stream to give a residue.
The residue was purified by chromatography over a silica gel column [sol-
vent, benzene–AcOEt (10 : 1→8 : 1→5 : 1→2 : 1)] to give (ꢁ)-MTPA ester
of 3 (3a, 4 mg) from 3, (ꢁ)-MTPA ester of 3ꢀ (3ꢀa, 4 mg) from 3ꢀ, (ꢁ)-
MTPA ester of 4a (4b, 3 mg) from 4a obtained from the organic acid frac-
tion, 4b (3 mg) from 4a obtained from the glycosidic acid fraction, (ꢁ)-
MTPA ester of 5a (5b, 1 mg) from 5a, and (ꢁ)-MTPA ester of 6 (6a, 5 mg)
from 6, respectively.
p-bromophenacyl 7-hydroxydodecanoate (5, 9 mg) from fr.
3 and p-
bromophenacyl 7-hydroxydecanoate (4, 43 mg) from fr. 4, respectively.
1: Colorless needles (n-hexane–AcOEt), mp 52—53 °C, [a]D20 ꢂ10.5°
1
(cꢅ1.5, CHCl3). H-NMR (in CDCl3, 400 MHz) d: 0.98 (3H, t, Jꢅ7.5 Hz,
H3-4), 1.24 (3H, d, Jꢅ7.0 Hz, H3-5), 1.55, 1.79 (each 1H, ddq, Jꢅ14.0, 7.5,
7.0 Hz, H-3), 2.55 (1H, ddq, Jꢅ7.0, 7.0, 7.0 Hz, H-2), 5.27 (2H, s,
OCH2CO), 7.63 (2H, ddd-like, Jꢅ8.5, 2.0, 2.0 Hz, aromatic H), 7.77 (2H,
ddd-like, Jꢅ8.5, 2.0, 2.0 Hz, aromatic H).
2: Colorless needles (n-hexane–AcOEt), mp 60—63 °C. 1H-NMR (in
CDCl3, 400 MHz) d: 1.82 (3H, dd-like, Jꢅ7.0, 1.0 Hz, H3-4), 1.88 (3H, t-
like, Jꢅ1.0 Hz, H3-5), 5.33 (2H, s, OCH2CO), 7.01 (1H, qq, Jꢅ7.0, 1.0 Hz,
H-3), 7.60 (2H, ddd-like, Jꢅ8.5, 2.0, 2.0 Hz, aromatic H), 7.78 (2H, ddd-
like, Jꢅ8.5, 2.0, 2.0 Hz, aromatic H).
3: Colorless needles (n-hexane–AcOEt), mp 98—99 °C, [a]D20 ꢁ13.8°
(cꢅ12.6, CHCl3). 1H-NMR (in CDCl3, 400 MHz) d: 1.23 (3H, d, Jꢅ7.0 Hz,
H3-5), 1.28 (3H, d, Jꢅ6.0 Hz, H3-4), 2.61 (1H, dq, Jꢅ7.0, 7.0 Hz, H-2), 3.97
(1H, dq, Jꢅ7.0, 6.0 Hz, H-3), 5.31, 5.41 (each 1H, d, Jꢅ16.5 Hz, OCH2CO),
7.61 (2H, ddd-like, Jꢅ8.5, 2.0, 2.0 Hz, aromatic H), 7.76 (2H, ddd-like,
Jꢅ8.5, 2.0, 2.0 Hz, aromatic H).
4: Colorless needles (n-hexane–AcOEt), mp 75—77 °C, [a]D15 ꢂ0.3°
1
(cꢅ7.7, CHCl3). H-NMR (in CDCl3, 400 MHz) d: 0.92 (3H, t, Jꢅ7.0 Hz,
3a: Syrup. 1H-NMR (in CDCl3, 600 MHz) d: 1.240 (3H, d, Jꢅ7.5 Hz, H3-
5), 1.434 (3H, d, Jꢅ6.0 Hz, H3-4), 2.928 (1H, dq, Jꢅ7.5, 7.5 Hz, H-2), 3.555
(3H, d-like, Jꢅ1.0 Hz, OCH3), 5.055 (1H, d, Jꢅ16.5 Hz, OCH2CO), 5.121
(1H, d, Jꢅ16.5 Hz, OCH2CO), 5.459 (1H, dq, Jꢅ7.5, 6.0 Hz, H-3).
3ꢀa: Syrup. 1H-NMR (in CDCl3, 400 MHz) d: 1.240 (d, Jꢅ7.5 Hz, H3-5 of
R,R-form), 1.302 (Jꢅ7.5 Hz, H3-5 of S,S-form), 1.356 (d, Jꢅ7.5 Hz, H3-4 of
S,S-form), 1.434 (d, Jꢅ7.5 Hz, H3-4 of R,R-form), 2.928 (1H, dq, Jꢅ7.5,
7.5 Hz, H-2 of R,R-form), 2.960 (1H, dq, Jꢅ7.5, 7.5 Hz, H-2 of S,S-form),
3.512 (d-like, Jꢅ1.0 Hz, OCH3 of S,S-form), 3.555 (3H, d-like, Jꢅ1.0 Hz,
OCH3 of R,R-form), 5.055 (1H, d-like, Jꢅ16.5 Hz, OCH2CO of R,R-form),
5.121 (1H, d, Jꢅ16.5 Hz, OCH2CO of R,R-form), 5.180 (1H, d, Jꢅ16.5 Hz,
OCH2CO of S,S-form), 5.252 (d, Jꢅ16.5 Hz, OCH2CO of S,S-form), 5.460
(m, H-3 of R,R- and S,S-form).
H3-10), 1.71 (2H, tt, Jꢅ7.5, 7.5 Hz, H2-3), 1.33—1.47 (10H, H2-4, H2-5, H2-
6, H2-8, H2-9), 2.47 (2H, t, Jꢅ7.5 Hz, H2-2), 3.60 (1H, m, H-7), 5.25 (2H, s,
OCH2CO), 7.62 (2H, ddd-like, Jꢅ8.5, 2.0, 2.0 Hz, aromatic H), 7.76 (2H,
ddd-like, Jꢅ8.5, 2.0, 2.0 Hz, aromatic H). 13C-NMR (in CDCl3, 100 MHz)
d: 14.1 (C-10), 18.8, 24.8, 25.3, 29.1, 33.8, 37.2, 39.7, 65.7 (OCH2CO),
71.5 (C-7), 129.1, 129.3, 132.2, 133.0, 173.1 (C-1), 191.5 (CO-aromatic).
FD-MS m/z (%): 387 (24) [Mꢂ2ꢂH]ꢂ, 385 (24) [MꢂH]ꢂ, 343 (77) [Mꢂ
2ꢁC3H7]ꢂ, 341 (75) [MꢁC3H7]ꢂ, 314 (22) [Mꢂ2ꢂHꢁC3H7CH(OH)]ꢂ,
312 (19) [MꢂHꢁC3H7CH(OH)]ꢂ, 73 (100) [C3H7CH(OH)]ꢂ.
5: White powder. 1H-NMR (in CDCl3, 400 MHz) d: 0.89 (3H, t,
Jꢅ7.0 Hz, H3-12), 1.72 (2H, tt, Jꢅ7.5, 7.5 Hz, H2-3), 1.25—1.49 (14H, H2-
4, H2-5, H2-6, H2-8, H2-9, H2-10, H2-11), 2.48 (2H, t, Jꢅ7.5 Hz, H2-2), 3.59
(1H, m, H-7), 5.27 (2H, s, OCH2CO), 7.63 (2H, ddd-like, Jꢅ8.5, 2.0,
2.0 Hz, aromatic H), 7.77 (2H, ddd-like, Jꢅ8.5, 2.0, 2.0 Hz, aromatic H).
13C-NMR (in CDCl3, 100 MHz) d: 14.0 (C-12), 22.7, 24.8, 25.3, 25.3, 29.1,
31.9, 33.8, 37.2, 37.5, 65.7 (OCH2CO), 71.9 (C-7), 129.1 (aromatic), 129.3
(aromatic), 132.3 (aromatic), 133.1 (aromatic), 173.1 (C-1), 191.5 (CO-aro-
matic). FD-MS m/z (%): 415 (55) [Mꢂ2ꢂH]ꢂ, 413 (53) [MꢂH]ꢂ, 343 (72)
[Mꢂ2ꢁC5H11]+, 341 (70) [MꢁC5H11]ꢂ.
4b: Syrup. 1H-NMR (in CDCl3, 600 MHz) d: 0.850 (3H, t, Jꢅ7.5 Hz, H3-
10), 2.285 (2H, t, Jꢅ7.5 Hz, H2-2), 3.545 (3H, d-like, Jꢅ1.0 Hz, OCH3),
3.664 (3H, s, COOCH3), 5.092 (1H, m, H-7).
5b: Syrup. 1H-NMR (in CDCl3, 600 MHz) d: 0.840 (3H, t, Jꢅ7.0 Hz, H3-
12), 2.287 (2H, t, Jꢅ7.5 Hz, H2-2), 3.550 (3H, d-like, Jꢅ1.0 Hz, OCH3),
3.666 (3H, s, COOCH3), 5.077 (1H, m, H-7).
6a: Syrup. 1H-NMR (in CDCl3, 600 MHz) d: 0.855 (3H, t, Jꢅ7.5 Hz, H3-
14), 2.602 (1H, dd, Jꢅ4.5, 16.0 Hz, Ha-2), 2.692 (1H, dd, Jꢅ8.0, 16.0 Hz,
Hb-2), 3.540 (3H, q, Jꢅ1.0 Hz, OCH3), 3.550 (3H, q, Jꢅ1.0 Hz, OCH3),
3.659 (3H, s, COOCH3), 5.093 (1H, m, H-11), 5.465 (1H, m, H-3).
Preparation of (ꢂ)-MTPA Esters of 4a and 5a (ꢂ)-MTPACl (15 mg)
was added to individual solutions of 4a (2 mg) and 5a (1 mg) in pyridine
(0.5 ml) and CCl4 (5 drops), and treated in the same way as in the case of the
preparation of (ꢁ)-MTPA esters to give the (ꢂ)-MTPA ester of 4a (4c,
2 mg) from 4a and (ꢂ)-MTPA ester of 5a (5c, 1 mg) from 5a, respectively.
4c: Syrup. 1H-NMR (in CDCl3, 600 MHz) d: 0.917 (3H, t, Jꢅ7.5 Hz, H3-
10), 2.243 (2H, t, Jꢅ7.5 Hz, H2-2), 3.560 (3H, s like, OCH3), 3.663 (3H, s,
COOCH3), 5.089 (1H, m, H-7).
Preparation of 4a and 5a Compounds 4 (10 mg) and 5 (9 mg) were
each heated with 1 M KOH (1 ml) at 95 °C for 1 h. After cooling, the mixture
was acidified (pH 4) with 1 M HCl, diluted by H2O (10 ml), then extracted
with ether (5 mlꢃ4). The ether layer was methylated with diazomethane–
ether, and then the residue was successively subjected to a silica gel column
[solvent, n-hexane–AcOEt (4 : 1→3 : 1→0 : 1)] and HPLC [column, Kusano
C.I.G. Si, 22 mm i.d.ꢃ10 cm; solvent, n-hexane–AcOEt (2 : 1)] to give
methyl 7-hydroxydecanoate (4a, 3 mg) from 4 and methyl 7-hydroxydode-
canoate (5a, 4 mg) from 5, respectively.
4a: White powder. 13C-NMR (in CDCl3, 100 MHz) d: 14.1 (C-10), 18.8,
24.9, 25.3, 29.2, 34.0, 37.2, 39.7, 51.5 (OCH3), 71.5 (C-7), 174.3 (C-1).
5a: White powder. 13C-NMR (in CDCl3, 100 MHz) d: 14.0 (C-12), 22.6,
24.9, 25.3, 25.3, 29.2, 31.9, 34.0, 37.2, 37.5, 51.5 (OCH3), 71.9 (C-7), 174.2
(C-1).
5c: Syrup. 1H-NMR (in CDCl3, 600 MHz) d: 0.876 (3H, t, Jꢅ7.0 Hz, H3-
12), 2.245 (2H, t, Jꢅ7.5 Hz, H2-2), 3.559 (3H, d-like, Jꢅ1.0 Hz, OCH3),
3.664 (3H, s, COOCH3), 5.076 (1H, m, H-7).
Acidic Hydrolysis of the Glycosidic Acid Fraction The glycosidic
acid fraction (0.86 g) in 2 M HCl (3 ml) was heated at 95 °C for 1 h. The reac-
tion mixture was diluted with H2O (5 ml) and then extracted with ether
(5 mlꢃ4). The ether extract was dried over MgSO4 and concentrated in
vacuo to give a residue (142 mg). Treatment of the residue with diazo-
methane–ether, followed by evaporation, gave a white powder, which was
chromatographed over a silica gel column [solvent, n-hexane–AcOEt
(10 : 1→5 : 1→2 : 1→0 : 1)] to afford methyl 7-hydroxydecanoate (4a,
35 mg) and methyl ipurolate (6, 53 mg).
Isolation of 7—11 The glycosidic acid fraction (4.29 g) was chro-
matographed over silica gel column [solvent, CHCl3–MeOH–H2O
(7 : 3 : 0.5→6 : 4 : 1→0 : 0 : 1)] to afford fr. 7 (0.66 g) and fr. 8 (2.50 g). Fr. 7
(0.66 g) in MeOH (3 ml) was methylated with diazomethane–ether. The con-
centrated reaction mixture was chromatographed over a silica gel column
[solvent, CHCl3–MeOH–H2O (14 : 2 : 0.05→0 : 1 : 0)] to give fr. 9 (426 mg)
and fr. 10 (180 mg). Fr. 9 was subjected to HPLC [column, Kusano C.I.G.
Si, 22 mm i.d.ꢃ30 cm; solvent, n-hexane–AcOEt (1 : 4)] to furnish the
methyl ester (7, 326 mg) of quamoclinic acid B and fr. 11 (38 mg). Fr. 8 was
dissolved in 1,4-dioxane–H2O (3 : 1, 40 ml) and neutralized with triethyl-
amine, and then the solvent was removed. A mixture of the residue and
phenacylbromide (0.8 g) in dimethylformamide (50 ml) was heated at 90 °C
for 2.5 h. The mixture was concentrated to dryness, and the residue was
chromatographed over a silica gel column [solvent, CHCl3–MeOH–H2O
(8 : 2 : 0.2→7 : 3 : 0.5→6 : 4 : 1→0 : 1 : 0)] to afford fr. 12 (720 mg), fr. 13
(1878 mg), fr. 14 (261 mg), and fr. 15 (241 mg). Fr. 13 was subjected
to HPLC [column, Kusano C.I.G. Si, 22 mm i.d.ꢃ30 cm; solvent,
6: Colorless needles (n-hexane–AcOEt), mp 67—69 °C, [a]D15 ꢂ13.1°
(cꢅ3.8, CHCl3). 13C-NMR (in CDCl3, 100 MHz) d: 14.1 (C-14), 18.8, 25.5,
25.6, 29.5, 29.5, 29.6, 36.6, 37.5, 39.7, 41.3, 51.7 (OCH3), 68.0 (C-3), 71.6
(C-11), 173.4 (C-1).
The aqueous layer was neutralized with 1 M KOH and the mixture was
evaporated. Desalting of the residue by chromatography on a Sephadex LH-
20 column (solvent, MeOH) followed by evaporation afforded a syrup
(619 mg, sugar fraction) which was subjected to TLC analysis [condition 1:
plate, Avicel SF (Funakoshi Pharm. Co.); solvent, n-BuOH–pyridine–H2O

May 2010
671
Table 3. 1H-NMR Spectral Data for 10a and 11a (in Pyridine-d5, 600 MHz)
10a
11a
4.82 d (7.5)
10a
11a
Fuc-1
4.72 d (7.5)
Fucꢀ-1
5.62 d (7.5)
2
3
4
4.44 dd (7.5, 9.5)
4.39 dd (3.5, 9.5)
4.04 d (3.5)
ca. 4.50
ca. 4.50
ca. 4.08
2
3
4
4.25 dd (7.5, 9.5)
4.21 dd (3.5, 9.5)
3.98 d (3.5)
5
3.78 q (6.0)
ca. 3.93
5
ca. 4.07
6
1.41 d (6.0)
1.43 d (6.0)
6
1.52 d (6.0)
Glc-1
5.52 d (7.0)
4.13 dd (7.0, 9.0)
ca. 4.11
5.64 d (7.5)
ca. 4.20
Quiꢀ-1
5.13 d (8.0)
ca. 4.09
3.91 dd (9.0, 9.0)
3.52 dd (9.0, 9.0)
3.69 dd (9.0, 6.0)
1.60 d (6.0)
5.00 d (7.5)
ca. 4.05
ca. 4.08
3.59 dd (9.0, 9.0)
3.74 dq (9.0, 6.0)
1.71 d (6.0)
2
3
4
5
6
2
3
4
5
4.15 dd (9.0, 9.0)
ca. 4.06
3.63 ddd (3.0, 5.0, 9.0)
4.30 dd (3.0, 11.0)
ca. 4.19
4.04 dd (9.0, 9.0)
3.60 ddd (3.0, 5.5, 9.0)
4.28 dd (3.0, 11.5)
4.17 dd (5.5, 11.5)
6.22 d (1.5)
4.95 dd (1.5, 3.5)
5.12 dd (3.5, 9.5)
4.67 dd (9.5, 9.5)
4.94 dq (9.5, 6.0)
1.89 d (6.0)
6
Fucꢄ-1
4.98 d (7.5)
Rha-1
6.30 d (2.0)
2
3
4
5
4.36 dd (7.5, 9.5)
4.07 dd (3.0, 9.5)
4.00 d (3.0)
3.84 q (6.5)
1.48 d (6.5)
2
3
4
5
4.92 dd (2.0, 3.0)
5.19 dd (3.0, 9.5)
4.73 dd (9.5, 9.5)
5.02 dq (9.5, 6.0)
1.94 d (6.0)
6
6
Rhaꢀ-1
6.05 d (1.5)
Glcꢀ-1
5.93 d (7.5)
6.10 d (8.0)
ca. 3.93
4.40 dd (9.0, 9.0)
4.10 dd (9.0, 9.0)
4.00 ddd (2.0, 6.0, 9.0)
ca. 4.49
ca. 4.18
5.81 d (7.5)
3.95 dd (7.5, 9.0)
4.25 dd (9.0, 9.0)
3.68 dd (9.0, 9.0)
ca. 4.05
2
3
4
5
6
4.64 dd (1.5, 3.5)
4.47 dd (3.5, 9.5)
4.27 dd (9.5, 9.5)
4.90 dq (9.5, 6.0)
1.65 d (6.0)
2.89 dd (8.0, 15.0)
2.86 dd (5.0, 15.0)
4.55 m
2
3
4
5
6
3.97 dd (7.5, 9.0)
4.35 dd (9.0, 9.0)
ca. 4.11
3.94 ddd (2.0, 6.0, 9.0)
4.41 dd (2.0, 12.5)
4.16 dd (6.0, 12.5)
Ag-2
2.89 dd (7.5, 15.0)
2.86 dd (5.0, 15.0)
4.54 m
3.84 m
0.90 t (7.0)
Qui-1
3
11
14
2
3
4
5
6
3.87 m
0.89 t (7.0)
1.60 d (6.0)
d in ppm from TMS (coupling constants (J) in Hz are given in parentheses). Fuc, fucopyranosyl; Glc, glucopyranosyl; Rha, rhamnopyranosyl; Qui, quinovopyranosyl; Ag,
aglycone.
MS m/z: 1167 [MꢁH]ꢁ, 1021 [1167ꢁ146]ꢁ, 859 [1021ꢁ146]ꢁ, 713
CHCl3–MeOH–H2O (7 : 3 : 0.5)] to give fr. 16 (40 mg), fr. 17 (92 mg), fr. 18
(449 mg), the phenacyl ester (10, 212 mg) of quamoclinic acid E, and fr. 19
(111 mg). Preparative HPLC (column, Inertsil ODS, 20 mm i.d.ꢃ25 cm; sol-
vent, 75% MeOH) of fr. 18 (449 mg) yielded the phenacyl ester (9, 49 mg)
of quamoclinic acid D, the phenacyl ester (11, 90 mg) of quamoclinic acid F,
and the phenacyl ester (8, 209 mg) of quamoclinic acid C.
Preparation of 7a—11a Compounds 7 (30 mg), 8 (100 mg), 9 (49 mg),
10 (100 mg), and 11 (90 mg) were each heated with 1 M KOH (3 ml) at 95 °C
for 1 h. After cooling, the mixture was acidified (pH 3) with 1 M HCl and
then extracted with ether (3 mlꢃ3). The aqueous layer was subjected to MCI
gel CHP 20 (solvent, H2O→acetone) to give quamoclinic acid B (7a, 26 mg)
from 7, quamoclinic acid C (8a, 80 mg) from 8, quamoclinic acid D (9a,
39 mg) from 9, quamoclinic acid E (10a, 87 mg) from 10, and quamoclinic
acid F (11a, 79 mg) from 11, respectively.
1
[859ꢁ146]ꢁ, 567 [713ꢁ146]ꢁ, 405 [567ꢁ162]ꢁ. H-NMR d: see Table 1.
13C-NMR d: see Table 2. JC-1–H-1 (Hz): Fuc (159.0), Fucꢀ (162.0), Glc
(163.8), Glcꢀ (162.7), Quiꢀ (162.7), Rha (174.0). Anal. Calcd for
C50H88O30·H2O: C, 50.58; H, 7.44. Found: C, 50.55; H, 7.48.
10a: White powder, [a]D22 ꢁ28.5° (cꢅ1.0, MeOH). Negative-ion FAB-
MS m/z: 1313 [MꢁH]ꢁ, 1167 [1313ꢁ146]ꢁ, 1021 [1167ꢁ146]ꢁ, 859
[1021ꢁ162]ꢁ, 713 [859ꢁ146]ꢁ, 567 [713ꢁ146]ꢁ, 405 [567ꢁ162]ꢁ, 259
[405ꢁ146]ꢁ. 1H-NMR d: see Table 3. 13C-NMR d: see Table 2. JC-1–H-1
(Hz): Fuc (156.7), Fucꢀ (158.7), Fucꢄ-1 (158.7), Glc (162.8), Glcꢀ (162.8),
Quiꢀ (158.7), Rha (173.0). Anal. Calcd for C56H98O34·1/2H2O: C, 50.79; H,
7.46. Found: C, 50.83; H, 7.59.
11a: White powder, [a]D17 ꢁ42.2° (cꢅ1.0, MeOH). Negative-ion FAB-
MS m/z: 1313 [MꢁH]ꢁ, 1167 [1313ꢁ146]ꢁ, 1021 [1167ꢁ146]ꢁ, 859
[1021ꢁ162]ꢁ, 567 [859ꢁ146ꢃ2]ꢁ, 405 [567ꢁ162]ꢁ, 259 [405ꢁ146]ꢁ. 1H-
NMR d: see Table 3. 13C-NMR d: see Table 2. JC-1–H-1 (Hz): Fuc (159.7),
Glc (162.8), Glcꢀ (162.8), Qui (168.9), Quiꢀ (158.7), Rha (173.0), Rhaꢀ
(168.9). Calcd for C56H98O34: C, 51.14; H, 7.51. Found: C, 51.11; H, 7.71.
Acidic Hydrolysis of 7 and 8a—11a Compounds 7 (8 mg), 8a (10 mg),
9a (11 mg), 10a (10 mg), and 11a (6 mg) were each heated with 1 M HCl
(1 ml) at 95 °C for 1 h. The reaction mixture was diluted with H2O (5 ml) and
extracted with ether (3 mlꢃ3). The extract was dried over MgSO4 and con-
centrated in vacuo to give a residue. The residue was treated with dia-
zomethane–ether and subjected to GC [column, 3.2 mm i.d.ꢃ2.0 m glass
column packed with Silicone OV-17 Uniport HP 80/100; carrier gas N2,
1.5 kg/cm2; temperature, 140 °C; tR (min): 4.95 (methyl 7-hydroxyde-
canoate) from 7; temperature, 190 °C; tR (min): 7.66 (methyl ipurolate) from
8a—11a].
7a: Syrup, [a]D16 ꢁ40.5° (cꢅ2.5, MeOH). Negative-ion FAB-MS m/z: 333
[MꢁH]ꢁ, 187 [333ꢁ146]ꢁ. HR-negative-ion FAB-MS m/z: 333.1909
(Calcd for C16H2907: 333.1914). 1H-NMR (in pyridine-d5, 500 MHz) d: 0.91
(3H, t, Jꢅ7.0 Hz, H3-10 of Ag), 1.39 (2H, m, H2-4 of Ag), 1.61 (3H, d,
Jꢅ6.5 Hz, H3-6 of Qui), 1.77 (2H, tt, Jꢅ7.5, 7.5 Hz, H2-3 of Ag), 2.48 (2H,
t, Jꢅ7.5 Hz, H2-2 of Ag), 3.70 (1H, dd, Jꢅ9.0, 9.0 Hz, H-4 of Qui), 3.76
(1H, dq, Jꢅ9.0, 6.5 Hz, H-5 of Qui), 3.88 (1H, m, H-7 of Ag), 3.95 (1H, dd,
Jꢅ7.5, 9.0 Hz, H-2 of Qui), 4.13 (1H, dd, Jꢅ9.0, 9.0 Hz, H-3 of Qui), 4.79
(1H, d, Jꢅ7.5 Hz, H-1 of Qui). 13C-NMR (in pyridine-d5, 125 MHz) d: 14.3
(C-10 of Ag), 18.7 (C-6 of Qui), 18.8, 25.2, 25.6, 29.9, 34.7, 34.9, 37.7, 72.7
(C-5 of Qui), 75.6 (C-2 of Qui), 76.9 (C-4 of Qui), 78.3 (C-3 of Qui), 78.6
(C-7 of Ag), 103.4 (C-1 of Qui), 176.1 (C-1 of Ag).
8a: White powder, [a]D22 ꢁ33.3° (cꢅ1.0, MeOH). Negative-ion FAB-
MS m/z: 1167 [MꢁH]ꢁ, 1021 [1167ꢁ146]ꢁ, 859 [1021ꢁ162]ꢁ, 713
1
[859ꢁ146]ꢁ, 567 [859ꢁ2ꢃ146]ꢁ, 405 [567ꢁ162]ꢁ. H-NMR d: see Table
The aqueous layer was neutralized with 1 M KOH, and the mixture was
evaporated. Desalting of the residue with chromatography on a Sephadex
LH-20 column (solvent, MeOH) followed by evaporation gave a monosac-
charide fraction (3—8 mg) that was analyzed using TLC (condition 1). The
Rf value of the monosaccharide fraction of 7 was identical to that of D-
1. 13C-NMR d: see Table 2. JC-1–H-1 (Hz): Fuc (156.7), Glc (166.8), Glcꢀ
(166.8), Qui (164.8), Quiꢀ (156.7), Rha (172.9). Anal. Calcd for C50H88O30:
C, 51.36; H, 7.59. Found: C, 51.22; H, 7.78.
9a: White powder, [a]D22 ꢁ29.5° (cꢅ1.0, MeOH). Negative-ion FAB-

672
Vol. 58, No. 5
quinovose, and those of the monosaccharide fractions of 8a—11a were each
identical to those of D-glucose, D-fucose, L-rhamnose, and/or D-quinovose.
The monosaccharide fraction (3—4 mg) was subjected to GC analysis (con-
dition 2) as the trimethylsilyl ethers of the thiazolidine derivative, as re-
ported by Hara et al.6) The tR of the product of 7 was identical to that of the
D-quinovose derivative, and those of the products for 8a—11a were each
identical to those of the derivatives of L-rhamnose, D-fucose, D-glucose, and
D-quinovose.
2) Ono M., Kuwabata K., Kawasaki T., Miyahara K., Chem. Pharm.
Bull., 40, 2674—2680 (1992).
3) Ono M., Noda N., Kawasaki T., Miyahara K., Chem. Pharm. Bull., 38,
1892—1897 (1990).
4) Dale J. A., Mosher H. S., J. Am. Chem. Soc., 95, 512—518 (1973).
5) Ono M., Yamada F., Noda N., Kawasaki T., Miyahara K., Chem.
Pharm. Bull., 41, 1023—1026 (1993).
6) Hara S., Okabe H., Mihashi K., Chem. Pharm. Bull., 35, 501—506
(1987).
7) Kitagawa I., Nishio T., Kobayashi M., Kyogoku Y., Chem. Pharm.
Bull., 29, 1951—1956 (1981).
8) Seo S., Tomita Y., Tori K., Yoshimura Y., J. Am. Chem. Soc., 100,
3331—3339 (1978).
9) Kasai R., Okihara M., Asakawa J., Tanaka O., Tetrahedron Lett., 1977,
175—178 (1977).
Acetylation of 8 Compound 8 (8 mg) was dissolved in Ac2O–pyridine
(1 : 1, 1 ml), and the solution was left to stand at room temperature
overnight. After removal of the reagent under an N2 stream, the residue was
partitioned between ether (1 mlꢃ5) and H2O (0.5 ml). The ether layer was
concentrated in vacuo to afford the acetate of 8 (8b, 9 mg).
8b: White powder, 1H-NMR d: see Table 1.
References
10) Ono M., Honda F., Karahashi A., Kawasaki T., Miyahara K., Chem.
Pharm. Bull., 45, 1955—1960 (1997).
1) Shellard E. J., Plant Med., 9, 102—116 (1961).