Stoloniferins I–VII, resin glycosides from Ipomoea stolonifera

Pergnmon

STOLONIFERINS

0031-9422(93)EO197-M

I-VII, RESIN GLYCOSIDES STOLONIFERA*

Phymhmwy.

Vol. 36. No. L pp. MS- 371, 1994 Copyngbt Q 1994 Elrcwer Science Ltd Printed m Great Britam All n&r reserved 0031 9422/94 17.00 +o.m

FROM

NAOKI NODA, NAOTSUGU TAKAHASHI, TOSHIO KAWASAKI, KAZUMOTO MrYAHARAt

ZPOMOEA

and CHONG-REN YANGI

Faculty of Pharamaceutical Sciences, Setsunan University, 45-l. Nagaotoge-cho, Hirakata, Osaka 573-01, Japan; SPhytochemical Laboratory, Kunming Institute of Botany, Academia Sinica, Kunming, Yunnan, China (Received 18 May 1993)

Key Word Index-Ipomoea

stolonifera; Convolvulaceae;

resin glycosides; stoloniferins I-VII.

Abstract-Seven ether-soluble resin glycosides, stoloniferins, I-VII, were isolated in the pure state from the whole plants of Ipomoea stolonifera. Their structures were determined on the basis of chemical and spectral data.

INTRODUCTION

In the course of a systematic survey of the resin glycosides in Convolvulaceous plants, we have investigated the constituents of whole plants of Ipomoea stolonifera and have isolated seven compounds, which we have named stoloniferins I (l)-VII (7). This paper deals with the isolation and structural elucidation of these compounds. RFSUL’IS AND DlSCU.SSlON

The methanol extract of the whole plants of I. stoloniwas treated with chloroform-methanol-water (2: 1: 1) and the lower layer was concentrated to give a brown syrup. A part of it was subjected to silica gel and LH-20 column chromatography to give an ether-soluble resin glycoside fraction. This was hydrolysed with 3% potassium hydroxide to yield organic and glycosidic acid fractions. Gas chromatographic examination of the former revealed the presence of isobutyric, 2-methylbutyric, n-hexanoic, n-octanoic, n-decanoic and n-dodecanoic acids. Among them, 2-methylbutyric acid was found to have the S-configuration by Helmchen’s method [2]. The glycosidic acid fraction, on column chromatography, afforded three compounds, 8-10. Compound 8 was identified from its ‘H and 13C NMR spectra with simonic acid B. (S)-jalapinolic acid 1l-O-a-~rhamnopyranosyl (1+3)-0-[a-t--rhamnopyranosyl<1+4)]0-rhamnopyranosyl-( l-+4)-0-a+rhamnopyranosyl (1 -r2)-&&fucopyranoside, previously isolated from I. batatas (cv Simon) [33, while 9 and 10 were identified as operculinic acids A and C, respectively, previously obtained from 1. operculata [4].

fero

*Part 20 in the series ‘Resin glycosides’. For Part 19 see ref.

ct1. tAuthor to whom correspondence should be addressed.

The resin glycoside fraction was subjected to preparative HPLC and yielded l-7. Compound 1, on alkaline hydrolysis, gave simonic acid B (8) and 2(S)methylbutyric acid. The negative ion FAB mass spectrum of I exhibited a [M - H] - ion peak at m/z I I5 1, together with the fragment peaks at m/z 1067 Cl151 -(2methylbutyric acid group)]-, 837, 545, 417 and 271, indicating that 1 consisted of 1 mol of simonic acid B and 2 mol of 2(S)-methylbutyric acid. Observation of the diagnostic fragment peaks at m/z 545 and 417 [S, 63 revealed that the carboxyl group of the jalapinolic acid was combined with the second sugar (Rha) counted from the aglycone. The ‘HNMR spectrum of 1, when compared with that of 8, showed remarkable downfield shifts due to acylation at H-3 (0.97 ppm) of the first rhamnose (Rha) and H-2 (0.90 ppm) of the second rhamnose (Rha’), as well as H-4 (1.55 ppm) of the fourth rhamnose (Rha”‘), in addition to the unequivalent signals assignable to HZ-2 of the jalapinolic acid moiety. Therefore, the carboxyl group of the jalapinolic acid combines at OH-3 of Rha, and two 2(S)-methylbutyric acid groups are located at OH-2 of Rha’, and OH-4 of Rha”‘. Hence, the structure of stoloniferin I (1) was characterized. Compound 2, on alkaline hydrolysis, gave 8, together with isobutyric and n-decanoic acids. Its negative ion FAB mass spectrum exhibited a [M -HIion peak at m/z 1207 along with fragment peaks at m/z 1137,965,837, 545,417 and 271, indicating that 2 consisted of 1 mol each of 8, isobutyric and n-decanoic acids, and that the carboxy1 group of jalapinolic acid combined also with the second rhamnose (Rha). The ‘HNMR spectrum of 2 showed acylation shifts at H-3 of Rha, H-2 of Rha’and H4 of Rha”’ (0.96, 0.94 and 1.54 ppm, respectively) by comparison with that of 8 (Table 1). In order to clarify the location of ester linkages of the two organic acids, 2 was acetylated to give the octaacetate (2a). The EI mass spectrum of 2a showed fragment peaks at m/z 873, 655, 583,301 and 273, corresponding to the fragments shown

365

366

N. NODA et al.

AC0

OAc F

OAc

Resin glycosides from Ipomoea srolon$vw

in Table 2. Thus, n-decanoic acid was attached at OH-2 of Rha’ and isobutyric acid was located at OH-4 of Rha”. Hence, stoloniferin II (2) was concluded to have the structure shown. Compound 3 gave, in its negative ion FAB mass spectrum, a [M-H]ion peak at m/z 1221, together with the same characteristic fragment ion peaks at m/z 545,417 and 271 as those of 1 and 2. On alkaline hydrolysis, it gave 8 together with Z(S)-methylbutyric and ndecanoic acids. Comparison of the ‘H NMR spectra of 3 and 8 revealed acylation shifts of H-3 of Rha, H-2 of Rha’ and H-4 of Rha” in 3 (Table l), indicating that 3 differs only in the organic acid group, the isobutyric acid in 2 being replaced by Z(S)-methylbutyric acid in 3. Acetylation of 3 gave the octaacetate (3a) and its EI mass spectrum showed fragment peaks at m/z 887,655,315 and 273 (Table 2). Accordingly, n-decanoic and Z(S)-methylbutyric acid groups are located at OH-4 of Rha”’ and OH-2 of Rha’, respectively. The structure of stoloniferin III (3) is, thus, characterized as (S)-jalapinolic acid 11-O-xt_-rhamnopyranosy1-(1-+3)-0-[4-0-2@)-2-methylbutyryla-L-rhamnopyranosyl-( l-+4)-0-[(2-0-n-decanoyl)]-zL-rhamnopyranosyl-( l-4)-O-cr-L-rhamnopyranosyl(l-2)$-D-fucopyranoside, intramolecular 1,3”-ester. Compounds 4 and 5 gave, in their negative ion FAB mass spectra, the same [M -HIion peaks at m/z 1237, including the fragment ion peaks at m/z 1083, 545, 417, and 271. Both on alkaline hydrolysis afforded opercuhnic acid A (9) [4], together with Z(S)-methylbutyric and ndecanoic acids, indicating that 4 and 5 are isomeric. The ‘H NMR spectrum of 4, compared with that of 9, showed acylation shifts of H-3 of Rha, H-2 of Rha’ and H-4 of Rha” (Table 1). On the other hand, in the ‘HNMR spectrum of 5, acylation shifts of H-2 of Rha, H-2 of Rha’ and H-4 of Rha” were observed. The EI mass spectra of the peracetates 4a and 5s gave the same fragment ion peaks at m/z 945, 655, 597, 33 1 and 315 (Table 2). Therefore, the carboxyl group of the jalapinolic acid of 4 links with the OH-3 of Rha, while that of 5 combines with OH-2 of Rha to form a macrocyclic ester structure. Thus, the structures of 4 and 5 were determined as (!+jalapinolic acid 11-o-8-D-glUCOpyranOSyl-( l-+3)-0-[4-0-2(S)-2methylbutyryl]-~-t_-rhamnopyranosyl-(1+4)-0-[(2-0-ndecanoyl)]-r-t_-rhamnopyranosyl-( I -+4)-O-a-t-rhamnopyranosyl-(l-+2)@-fucopyranoside, intramolecular 1,3”ester, and (S)-jalapinolic acid 1I-O-,Y-~glucopyranosyl(l-+3)-0-[4-O-2 (S)-2-methylbutyryl]-z-L-rhamnopyranosyl-( 1+4)-0-[(2-O-n-decanoyl)]-z-L-rhamnopyranosyl(1+4)-0-a-L-rhamnopyranosyl-(1+2)-@-fucopyranoside, intramolecular lz’ester, respectively. Compound 6 exhibited a [M -HIion peak at m/z 1251 (negative ion FAB mass spectrum). It gave, on alkaline hydrolysis, 9 and n-hexanoic and n-decanoic acids. Its ‘H NMR spectrum showed the same signals (H2 of Rha, H-2 of Rha’ and H-4 of Rha”) shifted downfield as those of 5. The peracetate (6a) of 6 exhibited fragment ion peaks at m/z 959, 655, 611, 331 and 329 (Table 2). Therefore, 6 is analogous to 5 and differs only in that the Z(S)-methylbutyric acid group at OH-4 of Rha” in 5 is

367

replaced by n-hexanoic acid, the structure of stoloniferin VI (6) is characterized as shown. Compound 7 (m/z 1279 [M-H]-, negative ion FAB mass spectrum), on alkaline hydrolysis, gave 9 together with n-octanoic and n-decanoic acids. On the basis of the data from its ‘H NMR and the EI mass spectrum of its peracetate (7~) [Table 23, the structure is characterized as shown. Stoloniferins I-VII are all soluble in ether and have intramolecular ester structures. We have conventionally used Mayer’s classification for the so-called resin glycosides according to their solubility in ether, i.e. jalapin (soluble) and convolvulin (insoluble) [7]. However, with the occurence of ether-insoluble resin glycosides having a cyclic ester structure in 1. thuberosa [l], we propose to use the terms, ‘jalapin’ and ‘convolvulin’ not according to the solubility, but their structures, i.e. for the resin glycosides having intramolecular cyclic ester structures and for the others, respectively. Thus, stoloniferins I-VII represent ether-soluble jalapins. We found that this species also contains large quantities of ether-insoluble resin glycosides, so-called Mayer’s convolvulins (ca 90% based on the total resin glycosides); the isolation and structural elucidation of these compounds is in progress. EXPERIMENTAL

Mps: uncorr. ‘H and 13CNMR 600 MHz and 150 MHz, respectively, at 30” using TMS as int. standard. Negative ion FABMS: accelerating voltage 3 kv; matrix, triethanolamine; collision gas, Xe. EIMS: ionization voltage, 30 eV; accelerating voltage, 3-10 kv. Optical rotations were measured at 25”. CC: Merck silica gel 60 (230-400 mesh, #9385), Cosmosil 14OC,,-OPN (Nakalai Tesque) and Sephadex LH-20 (Pharmacia Fine Chemicals). Prep. HPLC: Inertsil PREP-ODS (20 x 250 mm, 10 pm, GL Sciences.) Isolation of stoloniferins I-VII. The MeOH extract (105 g) of the whole plants of I. stolonifera (cyrillo) J. F. Gmel (780 g) collected in Guangdong (September 1990), of which a herbarium specimen is deposited in Kunming Institute of Botany, was dissolved in CHCI,MeOH-H,O (2: 1: 1, 2.8 1) and shaken. The lower phase was coned to yield a brown syrup (96.6 g). This, on CC over silica gel (CHCI,-MeOH, 10 : l-+9: 1+4: l), gave fr.-1 (15.7 g), fr.-2 (Et,O-soluble resin glycoside fr., 11.9 g) and fr.-3 (52.8 g). Fr.-2 was chromatographed on a Sephadex LH-20 column (MeOH) to give fr.4 (0.5 g), fr.-5 (3.5 g) and fr.-6 (1.5 g). Fr.-5 on CC on Cosmosil 14OC,sOPN (MeOH) gave 3 frs, fr.-7 (0.4 g), fr.-8 (1.l g) and fr.-9 (1.3 g). Prep. HPLC of fr.7 (95% MeOH) gave l(10.7 mg), 2 (11.4 mg), 3 (77.9 mg) and 4 (22.3 mg). Prep. HPLC of fr.-9(MeOH)gave5(74.8 mg),6(35.2 mg)and7(21.8 mg). Determination ofcomponent organic and glycosidic acids of ether-soluble resin glycosides. A soln of the Et,Osoluble resin glycosides fr. (1.2 g) in 5% KOH-1,4dioxane (1: 1, 40 ml) was refluxed for 3 hr. The reaction mixt. was acidified (pH 4) and ether extracted with Et,0 (50 ml x 3). A part of the Et,0 layer was subjected to GC

368

N. NODA ef al. Table 1. ‘H NMR spectral

1

Fuc

2 3 4 5 6

2 2 3

Rha

Rha’

4 5 6 1 2 3 4 5 6

1

Rha”

2 3 4 5 6

I

Rha”’

2 3 4 5 6

3 4 s 6 Jla

1

2

3

8

4.8 1 (d, 7.9) 4.51 (dd, 7.9.9.5) 4.19 (dd, 9.5,3.5) 3.92 (dd 3.5,0.9) 3.X2 (dy. 0.9.6.2) 1.52 (d, 6.2) 6.33 (d, 1.5) 5.30 (dd, 1.5. 2.8) 5.62 (dd, 2.8,9.7) 4.66 (dd, 9.7,9.7) 5.00 (dq, 9.7.6.2) 1.57 (d, 6.2) 5.62 (d, 1.1) 5.78 (dd, I. L2.9) 4.52 (dd, 2.9.9.4) 4.21 fdd. 9.4,9.4t 4.32 (dq. 9.4‘6.1) 1.60 (d, 6.1) 5.58 (d. 1.5) 4.78 (dd, 1.5, 3.3) 4.43 (dd, 3.3,9.2) 4.22 (dd, 9.2,9.2f 4.27 (dq, 9.2.6.1) 1.72 (d, 6.1) 5.85 (d, I. 1) 4.65 (dd, 1. I, 3.4) 4.41 (dd, 3.5.9.7) 5.77 (dd, 9.7,9.7) 4.34 (dq, 9.1,6.2) I .39 (8.6.2)

4.81 (d, 7.6) 4.52 (dd, 7.6.9.5) 4.19 (dd. 9.5,3.4) 3.92 (br d, 3.4) 3.82 (br. y. 6.4) 1.52 (d, 6.4) 6.33 (d. f 3) 5.30 (dd, 1.5.2.8) 5.61 (dd, 2.8.9.X) 4.63 (dd, 9.8,9.8) 5.01 (dq, 9.8,6.7) 1.58 (d, 6.7) 5.65 (d, 1.5) 5.82 (dd, 1.5, 3.3) 4.52 (dd, 3.3.8.7) 4.25 (dd, 8.7, 8.7) 4.31 (dq, 8.7.6.4) 1.60 (d. 6.4) 5.57 (hr. s) 4.78 (dd, 1.5,3.0) 4.51 (dd. 3.0,9.5) 4.22 (dd, 9.5.9.5) 4.27 (dq, 9.5, 5.8) 1.71 (d. 5.8) 5.89 (br s) 4.62 (dd, 1.5.3.3) 4.42 (dd, 3.3,9.8) 5.76 (dd, 9X.9.8) 4.33 (dq, 9.8.6.1) 1.38 fd, 6.21)

4.80 (d, 7.9) 4.5 I (dd, 7.9.9.4) 4.18 (dd, 9.4,3.7) 3.91 (br d, 3.7) 3.82 (hr. q. 6.4) 1.52 (d, 6.4) 6.32 (d, 1.5) 5.30 (dd, 1.5.2.8) 5.61 (dd, 2.8. 10.1) 4.63 (dd. 10.1.9.8) 5.W (dq, 9.8,6. I) 1.57 (d. 6.1) 5.65 (d. 1.5) 5.82 (dd, 1S, 3.2) 4.52 (dd, 3.2,8.2) 4.25 (dd, 8.2,8.9) 4.32 (dq. 8.9,6.1) 1.60 (d, 6.1) 5.56 (d. I .O) 4.77 (dd. 1.O, 3.7) 4.50 (dd, 3.7,9.2) 4.21 (dd, 9.2.9.2) 4.27 (dq, 9.2.6. I ) 1.70 (dv6.t) 5.90 (hr s) 4.61 (dd, 1.5.3.4) 4.40 (dd. 3.4.9.8) 5.76 (dd, 9.8.9.8) 4.34 (dy, 9.8.6.1) 1.39 (d, 6.1) .-.

4.80 (d, 7.9) 4.00 (dd, ?.9,9.5) 4.16 (dd, 9.5, 3.4) 3.94 (hr d, 3.4) 3.80 (hr. q. 6.4) 1.52 (d, 6.4) 6.25 (hr. s, ) 4.&t* 4.65 (dd, 3.4,9.5) 4.3 i (dd, 9.5,9.5) 4.88 (dq, 9.5,6.1) 1.58 (d, 6.1) 6.19 (d, 1.5) 4.88 (dd, l&2.0) 4.56 (dd, 2.0,8.9) 4.48 (dd, 8.9,8.9) 4.33 (dq, 8.9.6.4) i .56 (d, 6.4) 5.69 (d, hr, s) 4.89 (dd, 1.O, 3.4) 4.55 (dd, 3.4,9.5) 4.25 (dd, 9.5q9.5) 4.74 (dq, 9.5,fi.l) 1.62 (d, 6.1) 5.69 (br s) 4.69 (dd, 1.O, 3.4) 4.37 (dd, 3.4.9.2) 4.22 (dd, 9.2,9.8) 4.34 (dq. 9.8.6.4) 1.56 (d, 6.4) 2.50 (f. 7.3) _. -. -

1 2

Gfc

2

II 16 Mba 2 4 5 Mba 2 4 5 Iba 2 3 4 Hexa 2 6 Ckta 2 8 Deca 2

data for 1-9 (in pyridine-d,)

_. -.

..-.

2.26 2.78 3.88 0.88 2.40 0.94 1.14 2.50 0.94

(ddd, 2.9, 7.2, 14.9) (ddd,2.4. 10.6, 14.9) (m) (f, 7.3) (1q.7.0.7.2) (I, 7.3) (d,7.0) (tq, 7.0) (f, 7.3) 1.20(d. 7.0)

2.28 (m) 2.93 (2. 12.5) 3.87 (m) 0.86 (1.7.0)

._

2.64 (qq, 7.0,7.0) 1.17 (d, 7.0) I .20 (d, 7.0) _. _.. -..

.-. -I

10 A 0.02 M solution *Splitting patterns

-_ -. .-

2.27 2.93 3.87 0.85 2.50 0.94 1.20

(ddd, 2,7,6.7, (1, 12.2) (m) (t, 7.0) (~q. 6.7.7.0) (f,?.3) (d, 7.0)

4.00 fm) _. 0.93 (I, 7.3)

_ _.. .-

-

-_

2.38 (t 7.3)

2.37 (t, 7.3)

0.95 (t, 7.0)

0.95 (t, 6.7)

in pyridine-d,; d in ppm from TMS (spiitting are complicated.

15.3)

patterns

.._ -. and coupling

constants),

J in

369

Resin glycosides from Ipomoea stolonijkra

4

5

6

7

9

4.82 (d, 7.9) 4.51 (dd, 7.9,9.5)

4.69(d, 7.3) 4.13(dd. 7.3,9.5) 4.02 (dd, 9.2.4.0) 3.95 (br d, 4.0) 3.73 (br. q. 6.4) 1.49 (d, 6.4) 5.49 (d, 1.5) 5.90(dd,l.S,3.7) 4.99(dd.3.1, 9.5) 4.14(dd, 9.5.9.5) 4.47 fdq, 9.5,6.4) 1.63 (d, 6.4) 5.87 (d, 1.8) 6.29 (dd, l&3.4) 4.75 (dd, 3.4,9.5)

4.69 (d, 7.3) 4.13 (dd. 7.3.9.8) 4.02 (dd, 9.8,3.7) 3.95 (br d, 3.7) 3.73 (br. q, 6.4) 1.49 (d, 6.4) 5.49 (d, 1.5) 5.90 (dd, 1.5, 3.4) 4.99 (dd, 3.4,9.5) 4.15 (dd, 9.5,9.S) 4.47 (dq, 9.5,6.4) 1.63 (d, 6.4) 5.87 (d, 1.5) 6.29 (dd, 1.5,3.S) 4.76 (dd, 3.5.8.9)

4.69 (d, 7.6) 4.13 (dd.7.6.9.3)

4.79 (d, 7.9) 4.47 (dd, 7.9.9.5) 4.13 (dd, 9.5,3.S) 3.93 (br d, 3.5) 3.79 (br. q, 6.4) 1.52 (d, 6.2) 6.22 (d, 1.3) 4.67 (dd,1.3,3.4)

4.32 (dd, 9.5.9.5) 4.37 (dq, 9.5, 5.8) I .6S (d, 5.8) 6.21 (d, 1.8) 4.91 (dd, l&3.4) 4.50 (dd, 3.4,9.2)

4.35 4.37 1.65 6.29 4.93 4.54

4.20 3.95 3.82 1.S2 6.33 5.24

(dd, 9J3.S) (br d, 3.5) (br. q, 6.2) (d, 6.2) (d, 1.3)

(dd, 1.3,2.8) 5.66 (dd, 2.8,9.9) 4.66 (dd, 9.9,9.9) 4.90 (dq, 9.5.6.1) 1.59 (d, 6.2) 5.62 (d, 1.6) 5.99 (dd, 1,6,3.3) 4.62 (dd, 3.3.8.8) 4.31 (dd, 8.8,8.8) 4.36. 1.62 (d, 6.1) 6.19 (d, 1.8) 4.88 (dd, 1.8.3.3) 4.43 (dd, 3.3,9.4) 5.71 (dd, 9.4,9.4) 4.36’

1.40 (d, 6.2)

-

5.08 (d, 7.5) 3.95 (dd, l.S,9.4) 4.12 (dd, 9.4,9.4) 4.17 (dd, 9.4.9.4)

3.87* 4.47 (dd, 2.8, 11.7) 4.36’ 2.29 (ddd, 2.8, 10.8,14.5)

4.73 (dd, 9.2,9.2) 4.37 (dq, 9.2,6.1) 1.40 (d, 6.1)

5.05 (d, 7.9) 3.95 (dd, 1.9,8.5) 4.03 (dd, 8.5,8.5) 3.93 (dd, 8.5.8.5) 3.75 (ddd, 8.5,6.1,2.4) 4.09 (dd. 6.1.12.2)

4.39 (dd, 2.4, 12.2) 2.27. 2.44’ 3.83 (m) 0.85 (t, 7.3)

2.70 (ddd, 2.8, 10.8, 14.5) 3.87*(m) 0.85 (t. 7.0) 2.50 (tq, 6.8,7.0) 0.93 (t, 7.3) 1.20 (d, 7.0) -.. _... -

2.52 (tq, 6.7,l.O) 0.94 (r, 7.3) 1.20 (d, 7.0) -_---

2.39 (ddd, 1.1,7.7,15.4) 2.45(ddd, 1.7.7.1, 15.4)

2.33 (m) -

0.93 (t, 7.3)

0.87 (t. 6.7)

(dd, 8.9.8.9) (dq, 8.9,5.8) (d, 5.8) (d, 1.5) (dd. 1.5.3.4)

(dd, 3.4.9.3) 5.77 (dd, 9.3.9.3) 4.37 (dq, 9.3,6.4) 1.42 (d, 6.4) 5.06 (d, 7.3) 3.96 (dd, 7.3,9.2) 4.04 3.94 3.75 4.10

(dd, 9.2,9.2) (dd, 9.2.9.2) (ddd, 9.2,5.8,3.0) (dd, 5.8, 11.9)

4.39 (dd, 3.0, 11.9) 2.29’ 2.46* 3.83 (m) 0.85 (t. 7.3) -_ -.. 2.43 (m) 0.78@,7.0) 2.34 (m) 0.88 (t, 6.7)

4.02(dd,9.3,4.0) 3.95(brd, 4.0) 3.72(br. q. 6.7) 1.49(d, 6.7) 5.49 (d. 1.5) 5.90 (dd, 1.5,3.4)

4.99 (dd, 3.4,9.S) 4.1 S (dd, 9.S, 9.5) 4.47 (dq, 9.5,6.1) 1.63 (d, 6.1)

5.88 (L 1.5) 6.30 (dd, 1.5.3.1) 4.76 fdd, 3.1,9.S) 4.33 (dd. 9.5.9.5) 4.38 (dq, 9.5, KS) 1.66 (d, 5.5) 6.23 (d, I.81 4.94 (dd, 1.8.3.1) 4.55 (dd, 3.1.9.2) 5.78 (dd, 9.2,9.2) 4.38 (dq, 9.2,6.1) 1.43 (d, 6.1) -_ .5.06 (4 7.3) 3.96 (dd, 1.3,9.S) 4.04 (dd, 9.5,9.S) 3.94 (dd, 9.5.9.5)

3.75 (ddd, 9.5,6.3,2.8) 4.10 (dd, 6.3, 11.6) 4.39 (dd, 2.8, 11.6) 2.28’ 2.44’ 3.83 (m) 0.85 (t, 7.3) 2.46 (m) 0.81 (r, 7.3) 2.34 (m) 0.87 (t, 6.7)

Hz are given in parentheses. All assignments are based on ‘H-‘H COSY and NOESY spectral data.

4.60(dd,3.4.9.2) 4.21(dd, 9.2,9.2) 4.86 (dq, 9.2,6.1) 1.60 (d, 6.1)

5.88 (d, 1.7) 5.17 (dd, 1.7,3.3) 4.72 (dd, 3.3,9.0) 4.48 (dd, 9.49.0) 4.39 (dq, 9.0,6.1) 1.59 (d, 6.1) 6.20 (d. 1.5) 4.87 idk 1.i. 3.6) 4.42 (dd, 3.6.9.4) 4.21 (dd, 9.4.9.4) 4.29 (dq, 9.4,6.2) 1.57 (d, 6.2) -

5.23 (d, 7.5) 3.9s (dd, 7.5.8.8) 4.19 (dd, 8.8,8.8) 4.10 (dd, 8.8.8.8) 3.94* 4.26 (dd, 6.1,11.9) 4.5 1 (dd, 2.4, 11.9) 2.52 (t, 7.4)

3.97’ 0.92 (I, 7.0)

-

Resin glycosides

from

(4 mg), isobutyric and n-decanoic acids from 2 (10 mg). Compound 8 (16 mg), Z(S)-methylbutyric and n-decanoic acids from 3 (11 mg). Compound 9 (23 mg), 2(s)methylbutyric and n-decanoic acids from 4 (3 1 mg). Compound 9 (14 mg), 2(S)-methylbutyric and n-decanoic acids from 5 (26 mg). Compound 9 (12 mg), n-hexanoic and ndecanoic acids from 6 (19 mg). Compound 9 (11 mg), noctanoic and n-decanoic acids from 7 (18 mg). Acetylation of 2-7. Each compound (lo-20 mg) was acetylated with AczO-pyridine (1: 1) to give the acetates, 2a-7a, respectively. Compound 2a, powder, mp 65-70”. [aIn -45.5” (MeOH; c 1.0). EIMS m/z (%): 873 (21), 655 (5), 583 (22), 301 (lOO), 273 (69). ‘H NMR (CD&): 6 1.97, 1.99, 2.02, 2.04, 2.06, 2.08, 2.08, 2.11 (each s, OCOMe). Compound 3a, powder, mp 83-89”. [z]n - 56.6” (MeOH; c0.5).E1MSm/z(%):887(14),655(5),597(17),315(100), 273 (72). ‘H NMR (CDCl,): 6 1.96, 1.99, 2.02, 2.03, 2.06, 2.07,2.08, 2.11 (each s, OCOMe). Compound 4a, powder, mp 68-73”. [rx]n -42.9” (MeOH; c 1.0). EIMS m/z (%): 945 (6), 655 (4), 597 (16), 331 (33). 315 (100). ‘HNMR (CDCI,): 6 1.95, 1.98, 1.99, 2.00, 2.00, 2.07, 2.08, 2.14, 2.20 (each s, OCOMe). Compound Sa, powder, mp 73-78”. [rx& - 16.7” (MeOH; ~2.1). EIMS m/z (%): 945 (7), 655 (6), 597(19), 331 (36), 315(100). ‘HNMR (CDCl,): 61.95, 1.99,2.0,2.01,2.04,2.07,2.10,2.17,2.19 (each s, OCOMe).

Ipomoea stolonijera

371

Compound 611,powder, mp 70-73”. [x]n - 18.5” (MeOH; ~2.5). EIMSm/z(%):959(2),655(7),611(31),331 (45),329 (100). ‘H NMR (CDCI,): 6 1.95, 1.95, 1.98,2.1 I, 2.17, 2.22, 2.29, 2.38, 2.39 (each s, OCOMe). Compound 7a, syrup. [a& - 18.2” (MeOH; c 1.7). EIMS m/z (%): 987 (5), 655 (9), 639 (17), 357 (lOO), 331 (45). ‘H NMR (CDCI,): 6 1.95, 1.96, 1.98, 2.13, 2.18, 2.23, 2.29, 2.39, 2.40 (each s, OCOMe).

REFERENCES

1. Ono, M., Nakagawa, K., Kawasaki, T. and Miyahara, K. (1993) Chem. Pharm. Bull. 41, 1925. 2. Helmchen, G., Volter, H. and Schule, W. (1977) Tetrahedron 43, 147. 3. Noda, N., Yoda, S., Kawasaki, T. and Miyahara, K. (1992) Chem. Pharm. Bull. 40, 3163. 4. Ono, M., Kawasaki, T. and Miyahara, K. (1989) Chem. Pharm. Bull. 37, 3209. 5. Noda, N., Kobayashi, H., Miyahara, K. and Kawasaki, T. (1998) Chem. Pharm. Bull. 36, 920. 6. Noda, N., Kogetsu, H., Kawasaki, T. and Miyahara, K. (1990) Phytochemistry 29, 3565. 7. Mayer, W. (1855) Justus Liehigs Ann. Chem. 95, 129.