470
Vol. 59, No. 4
HPLC [MeOH–H2O (1 : 4, v/v)] to give cis-entadamide A b-D-glucopyra-
noside (5, 4.4 mg), entadamide A b-D-glucopyranoside (6, 878 mg), and
phenylpropanol b-D-glucopyranoside (7, 9.2 mg).
Table 3. NMR Spectroscopic Data for Compound 5 (C: 125 MHz and H:
500 MHz, CD3OD), d in ppm and J in Hz
Fr. 5 (791 mg), Fr. 6 (871 mg), and Fr. 7 (1.70 g) were combined and sub-
jected to RPCC [120 g, MeOH : H2O (1 : 9→3 : 7→1 : 1→7 : 3→9 : 1→
MeOH)] to give 22 fractions [Fr. 5,6,7-1 (527 mg), Fr. 5,6,7-2 (282 mg), Fr.
5,6,7-3 (789 mg), Fr. 5,6,7-4 (254 mg), Fr. 5,6,7-5 (53.0 mg), Fr. 5,6,7-6
(21.2 mg), Fr. 5,6,7-7 (103 mg), Fr. 5,6,7-8 (43.7 mg), Fr. 5,6,7-9 (17.6 mg),
Fr. 5,6,7-10 (22.1 mg), Fr. 5,6,7-11 (8.0 mg), Fr. 5,6,7-12 (44.8 mg), Fr.
5,6,7-13 (20.0 mg), Fr. 5,6,7-14 (14.6 mg), Fr. 5,6,7-15 (16.6 mg), Fr. 5,6,7-
16 (6.0 mg), Fr. 5,6,7-17 (24.4 mg), Fr. 5,6,7-18 (478 mg), Fr. 5,6,7-19
(78.6 mg), Fr. 5,6,7-20 (55.0 mg), Fr. 5,6,7-21 (20.0 mg), and Fr. 5,6,7-22
(800 mg)]. Fr. 5,6,7-18 (450 mg) was separated by HPLC [MeOH–ace-
tone–H2O (3 : 2 : 5, v/v/v)] to give rheedeiosides A (1, 190 mg), B (2,
6.6 mg), C (3, 44.5 mg), and D (4, 21.2 mg).
C
H
1
2
3
169.1
115.9
148.8
40.4
69.9
19.2
104.6
75.1
77.9
71.7
78.0
62.7
—
5.89 d, 10
6.93 d, 10
3.40 2H, t, 7
3.62 2H, t, 7
2.32 3H, s
1ꢂ
2ꢂ
S–CH3
1ꢃ
2ꢃ
3ꢃ
4ꢃ
5ꢃ
6ꢃ
4.26 d, 8
3.19 dd, 8, 8
3.34 dd, 8, 8
3.28 dd, 8, 8
3.26 ddd, 8, 5, 2
3.58 dd, 12, 5
3.78 dd, 12, 2
The known compounds were identified by comparison of their physical
data ([a]D, IR, 1H- and 13C-NMR, and MS) with the reported values.
Rheedeioside A (1): Amorphous powder; [a]D24 ꢀ27.1 (cꢁ2.41, MeOH);
1
IR (film) nmax 3395, 2944, 1729, 1647, 1559, 1078, 1048 cmꢀ1; H-NMR
(600 MHz, pyridine-d5): Table 1; 13C-NMR (150 MHz, pyridine-d5): Table 2;
HR-ESI-MS (positive-ion mode): m/z 1608.6993 [MꢅNa]ꢅ (Calcd for rated under vacuum to give an aglycone (1b, 4.9 mg). The aglycone (1b) was
C72H115NO37Na: 1608.7040).
crystallized from EtOH–H2O and identified as entagenic acid (8). Entagenic
Rheedeioside B (2): Amorphous powder; [a]D23 ꢀ28.5 (cꢁ0.61, MeOH);
acid (1b): Colorless crystals, mp 292—296 °C. [a]D23 ꢅ28.6 (cꢁ0.49,
IR (film) nmax 3395, 2941, 1730, 1647, 1560, 1077, 1049 cmꢀ1; H-NMR
1
1
EtOH); H- (400 MHz, pyridine-d5) and 13C-NMR (100 MHz, pyridine-d5);
(500 MHz, pyridine-d5): Table 1; 13C-NMR (125 MHz, pyridine-d5): Table 2;
HR-ESI-MS (positive-ion mode): m/z 1566.6893 [MꢅNa]ꢅ (Calcd for
C70H113NO36Na: 1566.6935).
essentially the same as reported for entagenic acid (8)3,4); HR-ESI-MS (posi-
tive-ion mode) m/z: 511.3392 [MꢅNa]ꢅ (Calcd for C30H48O5Na: 511.3399).
The aqueous layer was subjected to HPLC analysis to detect D-glucosamine
hydrochloride, D-xylose and D-glucose, which were identified by comparison
of their retention times with those of authentic samples, D-glucosamine (tR:
6.0 min, positive optical rotation).
Rheedeioside C (3): Amorphous powder; [a]D23 ꢀ20.5 (cꢁ4.30, MeOH);
IR (film) nmax 3395, 2941, 1730, 1647, 1560, 1077, 1049 cmꢀ1; H-NMR
1
(600 MHz, pyridine-d5): Table 1; 13C-NMR (150 MHz, pyridine-d5): Table 2;
HR-ESI-MS (positive-ion mode): m/z 1608.7003 [MꢅNa]ꢅ (Calcd for
C72H115NO37Na: 1608.7040).
Acetylation of Rheedeioside A (1) A solution of 1 (17.3 mg) in 2 ml of
Ac2O–pyridine (1 : 1) and DMAP (2.0 mg) was stirred at room temperature
for 48 h. The reaction mixture was poured into ice-water and then extracted
Rheedeioside D (4): Amorphous powder; [a]D25 ꢀ24.0 (cꢁ2.10, MeOH);
IR (film) nmax 3388, 2945, 1730, 1648, 1559, 1079, 1047 cmꢀ1; H-NMR with EtOAc. The residue of the EtOAc extract was purified by silica gel CC
1
(600 MHz, pyridine-d5): Tables 2 and 3; 13C-NMR (150 MHz, pyridine-d5): [0.5 g, CHCl3
and then CHCl3 : MeOH : H2O] to give 1c (19.0 mg). Nonade-
Table 1; positive-ion HR-ESI-MS: m/z 1446.6471 [MꢅNa]ꢅ (Calcd for
C66H105NO32Na: 1446.6512).
1
caacetate (1c): Amorphous powder, [a]D22 ꢀ37.0 (cꢁ1.9, CHCl3); H-NMR
(600 MHz, CDCl3) d: 0.62 (1H, br d, Jꢁ12 Hz, H-5), 0.68, 0.75, 0.84, 0.85,
0.91, 0.98, 1.33 (3H each, all s, H3-24, 26, 25, 23, 29, 30 and 27, respec-
cis-Entadamide A b-D-Glucopyranoside (5): Amorphous powder; [a]D23
ꢀ12.0 (cꢁ0.44, MeOH); IR (film) nmax 3335, 2945, 1748, 1637, 1575, tively), 1.85 (3H, s, CH
3CON–), 1.89 (3H, s), 1.96 (3H, s), 1.97 (6H, s), 1.98
(9H, s), 1.99 (3H, s), 2.01 (3H, s), 2.02 (3H, s), 2.04 (6H, s), 2.05 (6H, s),
1074 cmꢀ1 1H-NMR (500 MHz, CD3OD): Table 3; 13C-NMR (125 MHz,
;
CD3OD): Table 3; HR-ESI-MS (positive-ion mode): m/z 346.0927 2.081 (6H, s), 2.083 (6H, s), 2.09 (3H, s), 2.10 (3H, s) (20ꢆCH
3COO–),
[MꢅNa]ꢅ (Calcd for C12H21NO7SNa: 346.0931).
3.00 (1H, m, H-3), 4.43 (1H, d, Jꢁ6 Hz, H-1ꢂ), 4.45 (1H, d, Jꢁ6 Hz, H-1ꢄ),
4.58 (1H, d, Jꢁ8 Hz, H-1 ), 4.60 (1H, d, Jꢁ6 Hz, H-1ꢃꢃ), 4.69 (1H, d,
Jꢁ7 Hz, H-1ꢃ), 4.97 (1H, br s, H-1ꢄꢃꢃ), 5.48 (1H, br t, Jꢁ4 Hz, H-12), 5.69
(1H, d, Jꢁ6 Hz, H-1ꢄꢃ);
Alkaline Hydrolysis of Rheedeioside A (1) A solution of rheedeioside
A (1) (38.3 mg) in 50% aqueous 1,4-dioxane (1.0 ml) was treated with 10%
aqueous KOH (1.0 ml) and stirred at 80 °C for 3 h. The reaction mixture was
neutralized with Dowex HCR W2 (Hꢅ form) and then the resin was removed
by filtration. The residue of the reaction mixture was subjected to RPCC
13C-NMR (150 MHz, CDCl3) d: 15.5 (C-25), 16.5
(C-24), 17.3 (C-26), 18.6 (C-6), 20.2 (C-27), 20.4, 20.54, 20.57, 20.59 (ꢆ2),
20.62 (ꢆ2), 20.65, 20.69 (ꢆ2), 20.71 (ꢆ3), 20.84, 20.93 (ꢆ2), 20.96, 21.1,
[Cosmosil (0.5 g), H2O–MeOH (100 : 0→4 : 1→2 : 3→0 : 100, v/v)] and on 21.3, 20.6 (20ꢆC
H3COO–), 23.2 (CH3CON–), 23.4 (C-11), 23.9 (C-30),
25.9 (C-2), 27.9 (C-23), 30.3 (C-20), 30.4 (C-22), 33.2 (C-29), 34.9 (C-7),
35.0 (C-21), 36.9 (C-10), 38.9 (C-1, 4), 40.9 (C-18), 41.3 (C-8), 46.1 (C-14),
46.3 (C-19), 46.9 (C-9), 47.0 (C-17), 55.0 (C-5), 69.6 (C-15), 76.2 (C-16),
evaporation of the 60% MeOH eluate, entagenic acid monodesmoside (1a,
25.2 mg) was obtained. Entagenic acid monodesmoside (1a): Amorphous
powder; [a]D23 ꢀ13.6 (cꢁ0.13, MeOH); IR (film) nmax 3364, 2942, 1718,
1635, 1569, 1050 cmꢀ1 1H-NMR (600 MHz, pyridine-d5) d: 0.78, 0.90, 90.1 (C-3), 126.4 (C-12), 141.0 (C-13), 172.8 (C-28), 103.4 (C-1ꢂ), 101.4
;
1.02, 1.09, 1.13, 1.14, 1.81, 2.11 (3H each, all s, H3-25, 24, 29, 26, 23, 30, (C-1ꢃ), 101.7 (C-1ꢄ), 101.3 (C-1ꢃꢃ), 93.1 (C-1ꢄꢃ), 100.5 (C-1 ), 107.1 (C-1ꢄ
27 and NHCOCH3), 3.22 (1H, dd, Jꢁ12, 4 Hz, H-3), 4.79 (1H, d, Jꢁ8 Hz, ꢃꢃ), 169.0, 169.1, 169.3, 169.42, 169.43, 169.5, 169.6, 169.70, 169.74,
H-1ꢃꢃ), 5.03 (1H, d, Jꢁ8 Hz, H-1ꢂ), 5.20 (1H, d, Jꢁ7 Hz, H-1ꢄ), 5.43 (1H, d,
169.75, 169.88, 169.93, 170.1, 170.16 (ꢆ2), 170.19, 170.3, 170.4, 170.6,
Jꢁ8 Hz, H-1ꢃ), 5.67 (1H, br s, H-12); 13C-NMR (150 MHz, pyridine-d5): 170.7, 171.4 (21ꢆCH
3COO–); HR-ESI-MS (positive-ion mode) m/z:
Table 1; HR-ESI-MS (positive-ion mode): m/z 1140.5555 [MꢅNa]ꢅ (Calcd
for C54H87NO23Na: 1140.5561). The residue of the 100% H2O eluate was
heated in 2 M HCl (1.0 ml) under reflux for 3 h. After cooling, the reaction
mixture was poured into ice-water and neutralized with Amberlite IRA-400
(OHꢀ form), and then the resin was removed by filtration. The filtrate was
extracted with EtOAc and the aqueous layer was subjected to HPLC analysis
[column: Shodex Asahipak NH 2P-50 4E, Fꢁ4.6 mm, Lꢁ25 cm; mobile
phase: MeCN–H2O (4 : 1, v/v); detection: optical rotation detector (JASCO
2090Plus); and flow rate: 1.0 ml/min] to detect D-apiose, D-xylose and D-glu-
cose, which were identified by comparison of their retention times with
those of authentic samples, D-apiose (tR 4.5 min, positive optical rotation), D-
xylose (tR: 7.5 min, positive optical rotation), and D-glucose (tR: 10.3 min,
positive optical rotation), respectively.
2406.9070 [MꢅNa]ꢅ (Calcd for C110H153NO56Na: 2406.9047).
Mild Alkaline Hydrolysis of Rheedeioside A (1) A solution of
rheedeioside A (1) (17.3 mg) in 0.5% NaOMe (1.0 ml) was stirred at 20 °C
for 18 h. The reaction mixture was neutralized with Dowex HCR W2 (Hꢅ
form) and then the resin was removed by filtration. The filtrate was extracted
with EtOAc and then the aqueous layer was evaporated under vacuum to
give a desacetylrheedeioside A (1a, 14.0 mg). The desacyl-rheedeioside A
(1a) was identified as rheedeioside
B
(2). Desacetylrheedeioside
A
24
(ꢁrheedeioside B) (1aꢁ2): Amorphous powder, [
a]D ꢀ25.1 (cꢁ0.14,
MeOH); HR-ESI-MS (positive-ion mode) m/z: 1566.6899 [MꢅNa]ꢅ (Calcd
for C70H113NO36Na: 1566.6934).
Acid Hydrolysis of Rheedeiosides B, C and D (2—4) Solutions of 2, 3
and 4 (1 mg each) were hydrolyzed in the same manner as described previ-
ously. HPLC analysis under the same conditions as above revealed the pres-
Acid Hydrolysis of Rheedeioside B Monodesmoside (1a) A solution
of 1a (12.5 mg) in 2 M HCl (1.0 ml) was heated under reflux for 3 h. After
cooling, the reaction mixture was poured into ice-water and neutralized with
Amberlite IRA-400 (OHꢀ form), and then the resin was removed by filtra-
tion. The filtrate was extracted with EtOAc and the organic layer was evapo-
ence of
D-glucosamine hydrochloride, D-xylose, D-apiose and D-glucose for
2, D-glucosamine hydrochloride, D-xylose and D-glucose for 3, and D-glu-
cosamine hydrochloride, D-apiose, D-xylose and D-glucose for 4. The sugars
were identified by comparison of their retention times with those of authen-