August 2001
977
Negative-ion FAB-MS: m/z 545 (MϪH)Ϫ. Positive-ion FAB-MS: m/z 569
(MϩNa)ϩ.
diol (6, 3.5 mg, 46.2%).
6: An amorphous powder, [a]D25 Ϫ61.1° (cϭ0.1, CHCl3). IR (film): 3453,
1632, 1028 cmϪ1 1H-NMR (500 MHz, CDCl3) d: 1.18 (3H, d, Jϭ6.4 Hz,
10-H3), 1.18, 1.33, 1.60 (3H, all s, 12, 11, 13-H3), 1.47 (1H, m), 1.82 (1H,
dd, Jϭ3.7, 14.0 Hz) (2-H2), 1.75 (1H, ddd, Jϭ1.8, 4.0, 14.0 Hz), 2.15 (1H,
ddd-like) (4-H2), 3.57 (1H, dd-like, 9-H), 4.22 (1H, dd-like, 3-H), 4.52 (1H,
br d, Jϭca. 6 Hz, 8-H), 5.30 (1H, br s, 7-H). 13C-NMR (125 MHz, CDCl3)
dC: given in Table 1.
Preparation of the (R)-MTPA Ester (6a) and the (S)-MTPA Ester (6b)
from (3S,5R,8R,9x)-5,8-Epoxy-6-megastigmene-3,9-diol (6) A solution
of 6 (1.0 mg) in CH2Cl2 (0.5 ml) was treated with (R)-MTPA (50 mg) in the
presence of EDC·HCl (50 mg) and 4-DMAP (20 mg), and the mixture was
stirred at 50 °C under an N2 atmosphere for 2 h. It was poured into ice-water
and the whole was extracted with AcOEt. The AcOEt extract was succes-
sively washed with 5% aqueous HCl, aqueous saturated NaHCO3, and brine,
then dried over MgSO4 and filtered. Removal of the solvent from the filtrate
under reduced pressure furnished a residue, which was purified on a normal-
phase silica gel column [0.6 g, n-hexane–AcOEt (5 : 1, v/v) to give 6a (0.5
mg, 17%). Through a similar procedure, 6b (1.4 mg, 48%) was prepared
from 6 (1.0 mg) by the use of (S)-MTPA (50 mg), EDC·HCl (50 mg), and 4-
DMAP (20 mg).
Officinoside D (4): A white powder, [a]D26 Ϫ14.5° (cϭ0.3, MeOH). IR
(KBr): 3432, 2940, 1167, 1075 cmϪ1. High-resolution positive-ion FAB-MS:
Calcd for C27H46O11Na (MϩNa)ϩ: 569.2938. Found: 569.2924. 1H-NMR
(500 MHz, pyridine-d5) d: 0.31 (1H, dd-like, 6-H), 0.89 (3H, d, Jϭ6.7 Hz,
15-H3), 1.07 (1H, ddd-like, 7-H), 1.24, 1.36 (3H each, both s, 13, 14-H3),
1.25 (1H, m, 3a-H), 1.47 (3H, d, Jϭ6.4 Hz, 6Ј-H3), 1.56 (2H, m, 2-H2), 1.62
(1H, m, 8a-H), 1.65 (1H, m, 9b-H), 1.72 (1H, m, 3b-H), 1.92 (1H, m, 9a-
H), 1.95 (1H, m, 4-H), 2.07 (1H, dd-like, 8b-H), 2.22 (1H, m, 5-H), 2.24
(1H, m, 1-H), 3.29, 4.16 (1H each, both d, Jϭ10.1 Hz, 12-H2), 4.80 (1H, d,
Jϭ7.7 Hz, 1Ј-H), 4.87 (1H, d, Jϭ7.9 Hz, 1Љ-H). 13C-NMR (125 MHz, pyri-
dine-d5) dC: given in Table 1. Negative-ion FAB-MS: m/z 545 (MϪH)Ϫ, 383
(MϪC6H11O5)Ϫ. Positive-ion FAB-MS: m/z 569 (MϩNa)ϩ.
.
Acid Hydrolysis of and Officinosides (1—4) A solution of 1—4 (5 mg
each) in 5% aq. H2SO4–1,4-dioxane (2 ml, 1 : 1, v/v) was heated under reflux
for 1 h. After cooling, the reaction mixture was neutralized with Amberlite
IRA-400 (OH- form) and the residue was removed by filtration. After re-
moval of the solvent from the filtrate in vacuo, the residue was transferred to
a Sep-Pak C18 cartridge with H2O and MeOH. The H2O eluate was concen-
trated and the residue was treated with L-cysteine methyl ester hydrochloride
(4 mg) in pyridine (0.5 ml) at 60 °C for 1 h. After reaction, the solution was
treated with N,O-bis(trimethylsilyl)trifluoroacetamide (0.2 ml) at 60 °C for 1
h. The supernatant was then subjected to GLC analysis to identify the deriv-
atives of D-glucose (i) from 1—4; D-fucose (ii) from 3 and 4; GLC condi-
tions: column: Supeluco STBTM-1, 30 mϫ0.25 mm (i.d.) capillary column,
column temperature: 230 °C, He flow rate: 15 ml/min, tR: i: 24.2 min, ii: 17.2
min.
6a: A white powder. 1H-NMR (500 MHz, CDCl3) d: 1.01, 1.11, 1.14 (3H
each, all s, 11,12, 13-H3), 1.25 (3H, d, Jϭ5.8 Hz, 10-H3), 1.76 (1H, dd,
Jϭ3.8, 15.2 Hz), 1.80 (1H, dd-like) (2-H2), 1.76 (1H, dd, Jϭ3.8, 15.2 Hz),
1.99 (1H, dd-like) (4-H2), 3.53, 3.57 (3H each, both s, MTPA-OMex2), 5.38
(1H, dd-like, 8-H), 5.24 (1H, br s, 7-H), 7.38—7.55 (10H).
6b: A white powder. 1H-NMR (500 MHz, CDCl3) d: 0.68, 0.82, 1.35 (3H
each, all s, 11, 12, 13-H3), 1.37 (3H, d, Jϭ5.8 Hz, 10-H3), 1.50 (1H, m), 1.64
(1H, dd-like) (2-H2), 1.96 (1H, dd, Jϭ4.1, 15.1 Hz), 2.11 (1H, dd-like) (4-
H2), 3.56 (6H, s, MTPA-OMex2), 5.06 (1H, br s, 7-H), 5.42 (1H, dd-like, 8-
H), 7.36—7.52 (10H).
Enzymatic Hydrolysis of Officinoside C (3) A solution of 3 (10 mg) in
0.2 M acetate buffer (pH 4.0, 2.0 ml) was treated with naringinase (Sigma
Co., Ltd., 20 mg) and the whole mixture was stirred at 40 °C for 24 h. The
reaction mixture was poured into EtOH and removal of the solvent under re-
duced pressure gave a product. The product was purified by normal-phase
silica gel column chromatography [1.0 g, CHCl3–MeOH–H2O (30 : 3 : 1,
lower layer, v/v)] to give selin-4(15)-en-3b,11-diol (7, 4.0 mg, 91.8%),
which were identified by comparison of their physical data ([a]D, IR, 1H-
NMR, 13C-NMR) with reported values.7)
Enzymatic Hydrolysis of Officinoside A (1) A solution of 1 (12 mg) in
0.2 M acetate buffer (pH 4.4, 2.0 ml) was treated with b-glucosidase (Orien-
tal Yeast Co., 20 mg) and the whole mixture was stirred at 38 °C for 48 h.
The reaction mixture was poured into EtOH and removal of the solvent
under reduced pressure gave a product. The product was purified by normal-
phase silica gel column chromatography [1.0 g, CHCl3–MeOH–H2O (30 : 3 :
1, lower layer, v/v)] to give (3S,5R,8S,9x)-5,8-epoxy-6-megastigmene-3,9-
diol (5, 4.3 mg, 61.5%), which was identified by comparison of the 1H-NMR
data and [a]D with reported values.4)
5: An amorphous powder, [a]D23 ϩ10.6 °C (cϭ0.1, CHCl3). IR (film):
1
3453, 1632, 1078 cmϪ1. H-NMR (500 MHz, CDCl3) d: 1.17 (3H, d, Jϭ6.4
Hz, 10-H3), 1.19, 1.32, 1.61 (3H, all s, 12, 11, 13-H3), 1.50 (1H, m), 1.84
(1H, dd, Jϭ4.0, 13.6 Hz) (2-H2), 1.75 (1H, ddd, Jϭ2.0, 4.0, 13.6 Hz), 2.15
(1H, ddd-like) (4-H2), 3.81 (1H, dd, Jϭ3.1, 6.4 Hz, 9-H), 4.24 (1H, dd-like,
3-H), 4.71 (1H, br d, Jϭca. 5 Hz, 8-H), 5.37 (1H, br s, 7-H). 13C-NMR (125
MHz, CDCl3) dC: given in Table 1.
Preparation of the (R)-MTPA Ester (7a) and the (S)-MTPA Ester (7b)
from Selin-4(15)-en-3b,11-diol (7) A solution of 7 (0.6 mg) in CH2Cl2
(0.5 ml) was treated with (R)-MTPA (50 mg) in the presence of EDC·HCl
(50 mg) and 4-DMAP (20 mg), and the mixture was stirred at 50 °C under
an N2 atmosphere for 3 h. It was poured into ice-water and the whole was ex-
tracted with AcOEt. The AcOEt extract was successively washed with 5%
aqueous HCl, aqueous saturated NaHCO3, and brine, then dried over MgSO4
and filtered. Removal of the solvent from the filtrate under reduced pressure
furnished a residue, which was purified on a normal-phase silica gel column
[0.6 g, n-hexane–AcOEt (5 : 1, v/v) to give 7a (0.4 mg, 35%). Through a
similar procedure, 7b (0.4 mg, 19%) was prepared from 7 (1.1 mg) by the
use of (S)-MTPA (50 mg), EDC·HCl (50 mg), and 4-DMAP (20 mg).
Preparation of the (R)-MTPA Ester (5a) and the (S)-MTPA Ester (5b)
from (3S,5R,8S,9x)-5,8-Epoxy-6-megastigmene-3,9-diol (5) A solution
of 5 (0.8 mg) in CH2Cl2 (0.5 ml) was treated with (R)-MTPA (50 mg) in the
presence of EDC·HCl (50 mg) and 4-DMAP (20 mg), and the mixture was
stirred at 50 °C under an N2 atmosphere for 2 h. It was poured into ice-water
and the whole was extracted with AcOEt. The AcOEt extract was succes-
sively washed with 5% aqueous HCl, aqueous saturated NaHCO3, and brine,
then dried over MgSO4 and filtered. Removal of the solvent from the filtrate
under reduced pressure furnished a residue, which was purified on a normal-
phase silica gel column [0.6 g, n-hexane–AcOEt (5 : 1, v/v) to give 5a (1.1
mg, 47%). Through a similar procedure, 5b (0.9 mg, 44%) was prepared
from 5 (0.7 mg) by the use of (S)-MTPA (50 mg), EDC·HCl (50 mg), and 4-
DMAP (20 mg).
1
7a: A white powder. H-NMR (500 MHz, CDCl3) d: 0.72 (3H, s, 14-H3),
0.85 (2H, m, 9-H), 0.87 (2H, m, 1-H2), 1.20 (6H, s, 12, 13-H3), 1.64 (1H,
dd-like, 5-H), 1.66 (2H, m, 7-H), 1.81 (2H, m, 6-H2), 1.69 (1H, dd-like),
2.04 (1H, m) (2-H2), 3.61 (3H, s, MTPA-OMe), 4.51, 4.66 (1H each, both br
s, 15-H2), 5.40 (1H, m, 3-H), 7.38—7.58 (5H).
1
5a: A white powder. 1H-NMR (500 MHz, CDCl3) d: 1.17, 1.23, 1.28 (3H
each, all s, 12, 13, 11-H3), 1.26 (3H, d, Jϭ5.8 Hz, 10-H3), 1.68 (1H, dd,
Jϭ3.8, 15.2 Hz), 2.05 (1H, dd-like) (2-H2), 1.82 (1H, dd, Jϭ3.8, 15.2 Hz),
2.38 (1H, dd-like) (4-H2), 3.54, 3.58 (3H each, both s, MTPA-OMex2), 5.54
(1H, dd-like, 8-H), 5.70 (1H, br s, 7-H), 7.40—7.55 (10H).
7b: A white powder. H-NMR (500 MHz, CDCl3) d: 0.71 (3H, s, 14-H3),
0.85 (2H, m, 9-H), 0.86 (2H, m, 1-H2), 1.21 (6H, s, 12, 13-H3), 1.61 (1H,
dd-like, 5-H), 1.66 (2H, m, 7-H), 1.81 (2H, m, 6-H2), 1.66 (1H, dd-like),
2.02 (1H, m) (2-H2), 3.56 (3H, s, MTPA-OMe), 4.61, 4.95 (1H each, both br
s, 15-H2), 5.39 (1H, m, 3-H), 7.38—5.58 (5H).
5b: A white powder. 1H-NMR (500 MHz, CDCl3) d: 0.86, 1.20, 1.25 (3H
each, all s, 12, 11, 13-H3), 1.52 (3H, d, Jϭ5.8 Hz, 10-H3), 1.54 (1H, m), 1.93
(1H, dd-like) (2-H2), 1.89 (1H, dd, Jϭ4.1, 15.1 Hz), 2.49 (1H, dd-like) (4-
H2), 3.58 (6H, s, MTPA-OMex2), 5.52 (1H, dd-like, 8-H), 5.69 (1H, br s, 7-
H), 7.41—7.55 (10H).
Enzymatic Hydrolysis of Officinoside B (2) A solution of 2 (13 mg) in
0.2 M acetate buffer (pH 4.4, 2.0 ml) was treated with b-glucosidase (Orien-
tal Yeast Co., 20 mg) and the whole mixture was stirred at 38 °C for 48 h.
The reaction mixture was poured into EtOH and removal of the solvent
under reduced pressure gave a product. The product was purified by normal-
phase silica gel column chromatography [1.0 g, CHCl3–MeOH–H2O (30 : 3 :
1, lower layer, v/v)] to give (3S,5R,8R,9x)-5,8-epoxy-6-megastigmene-3,9-
Enzymatic Hydrolysis of Officinoside D (4) A solution of 4 (20 mg) in
0.2 M acetate buffer (pH 4.0, 2.0 ml) was treated with naringinase (40 mg)
and the whole mixture was stirred at 40 °C for 24 h. The reaction mixture
was poured into EtOH and removal of the solvent under reduced pressure
gave a product. The product was purified by normal-phase silica gel column
chromatography [1.0 g, CHCl3–MeOH–H2O (30 : 3 : 1, lower layer, v/v)] to
give flourensadiol (8, 7.6 mg, 87%), which was identified by comparison of
their physical data ([a]D, IR, 1H-NMR, 13C-NMR) with reported values.8)
References and Notes
1) Part III: Yoshikawa M., Murakami T., Kishi A., Kageura T., Matsuda
H., Chem. Pharm. Bull., 49 (7), 863—870 (2001).