6
W. Li et al.
74.6 (C-2000), 78.3 (C-3000), 70.9 (C-4000), 78.8 (C-5000), 62.1 (C-6000), 170.3 (60-OCOCH3), 20.4 (60-
OCOCH3); HR-ESI-MS: m/z 721.1925 [M þ Na]þ (calcd for C31H38O18Na, 721.1950).
3.3.2. 3-Deacetyltrifloroside (2)
25
White powder; C33H40O19; ½aꢀD : 212.85 (c 0.1, MeOH); IR (KBr): nmax 3410, 1755, 1631,
1579cm21; 1H NMR (pyridine-d5, 600 MHz): 5.56 (1H, brs, H-1), 7.80 (1H, d, J ¼ 2.2 Hz, H-3),
2.89(1H, m, H-5), 1.38(1H, m, H-6a), 1.28(1H, m, H-6b), 4.20 (1H, ddd, J ¼ 12.5, 11.0, 3.0 Hz, H-
7a), 4.06 (1H, m, H-7b), 5.28 (1H, ddd, J ¼ 16.0, 9.1, 7.7 Hz, H-8), 2.49 (1H, m, H-9), 5.00 (2H, m,
H-10), 5.40 (1H, J ¼ 7.5 Hz, H-10), 5.80 (1H, t, J ¼ 9.0 Hz, H-20), 4.31 (1H, m, H-30), 5.41 (1H, m,
H-40), 4.26(1H, m, H-50), 4.95(1H, m, H-60a), 4.40(1H, m, H-60b), 7.64(1H, dd, J ¼ 8.1, 1.2 Hz, H-
400), 6.62 (1H, t, J ¼ 8.1 Hz, H-500), 7.51 (1H, dd, J ¼ 8.1, 1.2 Hz, H-600), 5.56 (1H, J ¼ 7.5 Hz, H-
1000), 4.19 (1H, m, H-2000), 4.28 (1H, m, H-3000), 4.26 (1H, m, H-4000), 4.04 (1H, m, H-5000), 4.48 (1H, m,
H-6000a), 4.32 (1H, m, H-6000b), 2.00 (3H, s, 20-OCOCH3), 1.91 (3H, s, 60-OCOCH3). 13C NMR
(pyridine-d5, 150 MHz): 97.2 (C-1), 151.4 (C-3), 105.9 (C-4), 27.7 (C-5), 24.6 (C-6), 68.1 (C-7),
131.7 (C-8), 42.0(C-9), 120.3 (C-10), 164.7 (C-11), 96.9(C-10), 75.5(C-20), 68.5(C-30), 71.8(C-40),
74.5 (C-50), 64.0 (C-60), 114.0 (C-100), 152.5 (C-200), 147.1 (C-300), 122.2 (C-400), 118.7 (C-500), 122.9
(C-600), 169.6 (C-700), 102.8 (C-1000), 74.9 (C-2000), 78.3 (C-3000), 70.9 (C-4000), 78.8 (C-5000), 62.1 (C-6000),
169.7(20-OCOCH3), 20.4(20-OCOCH3), 170.1(60-OCOCH3), 20.5(60-OCOCH3);HR-ESI-MS: m/
z 763.2024 [M þ Na]þ (calcd for C33H40O19Na, 763.2056).
3.3.3. 2-Deacetyltrifloroside (3)
25
White powder; C33H40O19; ½aꢀD : 212.02 (c ¼ 0.1, MeOH); IR (KBr): nmax 3427, 1763, 1633,
1581 cm21; 1H NMR (pyridine-d5, 600 MHz): 5.54 (1H, brs, H-1), 7.84 (1H, d, J ¼ 2.2 Hz, H-3),
2.95 (1H, m, H-5), 1.41 (1H, m, H-6a), 1.29 (1H, m, H-6b), 4.22 (1H, ddd, J ¼ 12.5, 11.0,
3.0 Hz, H-7a), 4.10 (1H, m, H-7b), 5.30 (1H, ddd, J ¼ 16.0, 9.1, 7.7 Hz, H-8), 2.50 (1H, m, H-9),
5.00 (2H, m, H-10), 5.35 (1H, J ¼ 7.5 Hz, H-10), 4.47 (1H, m, H-20), 5.83 (1H, t, J ¼ 9.6 Hz, H-
30), 5.50 (1H, t, J ¼ 9.0 Hz, H-40), 4.28 (1H, m, H-50), 4.62 (1H, dd, J ¼ 12.3, 4.8 Hz, H-60a),
4.44 (1H, m, H-60b), 7.63 (1H, dd, J ¼ 8.1, 1.2 Hz, H-400), 6.66 (1H, t, J ¼ 8.1 Hz, H-500), 7.51
(1H, dd, J ¼ 8.1, 1.2 Hz, H-600), 5.54 (1H, J ¼ 7.5 Hz, H-1000), 4.24 (1H, m, H-2000), 4.28 (1H, m,
H-3000), 4.25 (1H, m, H-4000), 4.03 (1H, m, H-5000), 4.44 (1H, m, H-6000a), 4.32 (1H, m, H-6000b), 1.98
(3H, s, 30-OCOCH3), 1.89 (3H, s, 60-OCOCH3). 13C NMR (pyridine-d5, 150 MHz): 97.0 (C-1),
151.3 (C-3), 106.1 (C-4), 27.8 (C-5), 24.6 (C-6), 68.1 (C-7), 131.7 (C-8), 42.0 (C-9), 120.3 (C-
10), 164.8 (C-11), 96.9 (C-10), 72.3 (C-20), 72.1 (C-30), 73.9 (C-40), 72.5 (C-50), 62.6 (C-60), 114.2
(C-100), 152.4 (C-200), 147.1 (C-300), 122.3 (C-400), 118.7 (C-500), 122.9 (C-600), 169.7 (C-700), 102.7
(C-1000), 74.5 (C-2000), 78.2 (C-3000), 70.9 (C-4000), 78.9 (C-5000), 62.1 (C-6000), 168.9 (30-OCOCH3),
20.6 (30-OCOCH3), 170.3 (60-OCOCH3), 20.3 (60-OCOCH3); HR-ESI-MS: m/z 763.2024
[M þ Na]þ (calcd for C33H40O19Na, 763.2056).
3.4. Enzymatic hydrolysis
Compounds 1–3 (each 3.0 mg) was mixed with b-glucosidase (3.0 mg) in water (1.0 mL) and
was shaken in a water bath at 378C for 12 h. After this, the reaction mixture was concentrated and
then subjected to silica gel (1.0 cm £ 15.0 cm, 40–63 mm) column chromatography with
CHCl3–MeOH (15:1, 60 mL) and CHCl3–MeOH–H2O (7:3:0.5, 60 mL) to afford aglycone and
a sugar fraction. The sugar fraction was concentrated to dryness using N2 gas. The resulting
residue was dissolved in dry pyridine (0.1 mL), and then L-cysteine methyl ester hydrochloride
in pyridine (0.06 M, 0.1 mL) was added to the solution. After heating the reaction mixtures at
608C for 2 h, 0.1 mL of trimethylsilylimidazole solution was added. Heating at 608C was