6
C. YE ET AL.
fractions (Fr.E9-1–E9-7). Fraction E9-3 (3.2 g) was further separated by MPLC (C ,
18
4
0–60 lm) eluted with MeOH–H O (1:3 to 1:0) to give compounds 10 (12.6 mg) and
2
1
2 (2.3 mg). Fraction E9-7 (1.4 g) was purified by MPLC (C , 20–45 lm) with
18
MeOH–H O (1:4 to 1:0) as the elution solvent to afford compounds 2 (4.5 mg) and 11
2
(
(
16.4 mg). Fraction E10 (55 g) was purified by MPLC (C , 40–60 lm) with MeOH–H O
18 2
1:19 to 1:0) to give six sub-fractions (Fr.E10-1–E10-6). Fraction E10-3 (6 g) was purified
by silica gel column chromatography eluted with CH Cl –MeOH (20:1 to 5:1) followed
2
2
by MPLC (C , 20–45 lm) with MeOH–H O (1:5 to 1:0) to give compounds 5 (196.9 mg)
1
8
2
and 8 (8.4 mg). Fraction E10-5 (12.1 g) was separated using MPLC (C , 40–60 lm) with
18
MeOH–H O (1:4 to 1:0) to obtain compounds 9 (10.2 mg) and 7 (2.3 g). Fraction E11
2
(
9 g) was purified by MPLC (C , 40–60 lm) with MeOH–H O (1:9 to 3:2) to give three
18 2
sub-fractions (Fr.E11-1–E11-3). Fraction E11-2 (6.10 g) was subjected to silica gel col-
umn chromatography and eluted with CH Cl –MeOH (20:1 to 12:1) to yield compound
2
2
4
(122.1 mg) and three sub-fractions (Fr.E11-2-2–E11-2-4). Fraction E11-2-4 (4.51 g) was
purified by MPLC (C , 40–60 lm) with MeOH–H O (1:9 to 1:0) to give compounds 1
18
2
(
46.7 mg), 3 (1.9 mg), and 6 (3.42 g).
0
0
0
(2S)-6,8-Dimethyl-5,7,3 ,4 -tetrahydroxyflavanone 4 -O-b-D-glucopyranoside (1):
Yellow amorphous powder, [a]25D : –197.6 (c 0.06, MeOH). HR-ESI-MS: m/z 479.1535
þ
1
[
(
5
3
2
M þ H] (calcd. for C H O , m/z 479.1548) . H-NMR (300 MHz. methanol-d ); d: 7.32
2
0
3
27 11
4
0
0
1 H, d, J ¼ 2.0 Hz, H-2 ), 6.99 (1 H, dd, J ¼ 8.0, 2.0 Hz, H-6 ), 6.78 (1 H, d, J ¼ 8.0 Hz, H-5 ),
0
0
00
.64 (1 H, dd, J ¼ 10.2, 5.3 Hz, H-2), 4.80 (1 H, d, J ¼ 7.9 Hz, H-1 ), 3.85 (1 H, m, H-6 a),
0
0
00
00
00
00
.72 (1 H, m, H-6 b), 3.45 (2 H, m, H-2 , H-3 ), 3.40 (1 H, m, H-5 ), 3.38 (1 H, m, H-4 ),
13
.91 (2 H, m, H-3), 2.06 (3 H, s, 8-CH ), 2.02 (3 H, s, 6-CH ); C-NMR (75 MHz, methanol-
3
3
0
0
d ), d: 198.5 (C-4), 164.2 (C-7), 160.3 (C-5), 159.4 (C-9), 152.4 (C-4 ), 150.5 (C-3 ), 128.0
4
0
0
0
0
0
0
(
(
C-1 ), 118.8 (C-6 ), 116.7 (C-5 ), 116.4 (C-2 ), 104.8 (C-6), 104.2 (C-8), 103.5 (C-1 ), 103.2
0
0
00
00
00
00
C-10), 78.1 (C-5 ), 78.0 (C-3 ), 75.5 (C-2), 75.0 (C-2 ), 71.4 (C-4 ), 62.5 (C-6 ), 42.9 (C-3),
8
.2 (6-CH ), 7.4 (8-CH ).
3
3
0
0
Quercetin
3-O-b-D-(6 -p-methoxybenzoyl)-galactopyranoside
(2):
Yellow
þ
amorphous powder, [a]25D : þ16.7 (c 0.04, MeOH). HR-ESI-MS: m/z 599.1396 [M þ H]
1
(
calcd. for C H O , m/z 599.1395). H-NMR (500 MHz, methanol-d ) d: 7.73 (1 H, d,
29 27 14 4
0
000
000
0
J ¼ 2.1 Hz, H-2 ), 7.67 (2 H, d, J ¼ 8.8 Hz, H-2 , 6 ), 7.58 (1 H, dd, J ¼ 8.5, 2.1 Hz, H-6 ),
0
000
000
6
(
.86 (1 H, d, J ¼ 8.5 Hz, H-5 ), 6.78 (2 H, d, H-3 , 5 ), 6.35 (1 H, d, J ¼ 2.0 Hz, H-8), 6.20
0
0
00
00
1 H, d, J ¼ 2.0 Hz, H-6), 5.31 (1 H, d, J ¼ 7.9 Hz, H-1 ), 4.47 (1 H, m, H-6 a), 4.33 (1 H, m,
0
0
00
00
H-6 b), 3.90 (1 H, m, H-4 ), 3.89 (1 H, m, H-2 ), 3.87 (1 H, m, H-5 ), 3.86 (3 H, s,
0
00
00 13
-OCH ), 3.63 (1 H, m, H-3 ). C-NMR (125 MHz, methanol-d ) d: 179.5 (C-4), 167.5
3 4
4
(
(
(
0
0
0
0
0
0
0
C-7 ), 165.8 (C-7), 164.9 (C-4 ), 163.0 (C-5), 158.7 (C-2), 158.3 (C-9), 149.8 (C-4 ), 145.8
0 000 000 0 000 0 0
C-3 ), 135.3 (C-3), 132.3 (C-2 , 6 ), 123.1 (C-6 , 1 ), 122.8 (C-1 ), 117.4 (C-2 ), 116.0
0 000 000 00 00
C-5 ), 114.5 (C-3 , 5 ), 105.5 (C-10), 104.4 (C-1 ), 99.9 (C-6), 94.7 (C-8), 75.0 (C-5 ),
00 00 00 00 000
4.8 (C-3 ), 73.0 (C-2 ), 70.4 (C-4 ), 64.6 (C-6 ), 55.9 (4 -OCH ).
3
7
3.4. Determination of absolute configuration of the sugars
Acid hydrolysis was carried out to obtain the free sugar residues. Compounds 1 and 2
ꢂ
(
3 mg each) were treated with 1.0 M HCl at 85 C for 2 h and the reaction mixture was
partitioned with EtOAc. The EtOAc residue was dissolved in dry pyridine after the