Z.-P. Xiao et al. / Bioorg. Med. Chem. 15 (2007) 3703–3710
3709
4.21 (s, 2H, ArCH2), 5.81 (s, 2H, H-3,5), 6.67 (d, 2H,
J = 8 Hz, H-30, 50), 7.00 (d, 2H, J = 8 Hz, H-20, 60),
9.16 (s, 1H, 40-OH), 10.34 (s, 1H, 4-OH), 12.21 (s, 2H,
2,6-OH). ESI-MS C14H13O5 [M+H]+ 260. Anal. Calcd
for C14H12O5: C, 64.61; H, 4.65. Found: C, 64.67; H,
4.62.
4.5.16. 7,8,40-Trihydroxyisoflavone (17). Compound 5
(260 mg, 1 mmol) in anhydrous DMF (1.6 mL) was
treated cautiously with BF3ÆEt2O (0.4 mL, 3.3 mmol)
on the ice-water bath. To this mixture was added a solu-
tion of CH3SO2Cl (0.3 mL, 3 mmol) in anhydrous DMF
(0.7 mL) at 50 ꢁC. The mixture was heated at 80 ꢁC for
3 h. The cooling product was poured into ice-cold aque-
ous NaOAc (50 mL, wt% = 10%). The mixture was ex-
tracted with EtOAc. After removal of the solvent, the
residue was purified via crystallization from aqueous
methanol (v% = 85%) to give compound 17 as colorless
needles (190 mg, 70%), which decomposed over 180 ꢁC.
1H NMR d: 6.80 (d, 2H, J = 7 Hz, H-30, 50), 6.95 (d, 1H,
J = 8 Hz, H-6), 7.38 (d, 2H, J = 7 Hz, H-20, 60), 7.46 (d,
1H, J = 8 Hz, H-5), 8.33 (s, 1H, H-2), 9.44 (s, 1H, 40-
OH), 9.52 (s, 1H, 8-OH), 10.31 (s, H, 7-OH). ESI-MS
C15H11O5 [M+H]+ 271. Anal. Calcd for C15H10O5: C,
66.67; H, 3.73. Found: C, 66.61; H, 3.75.
4.5.13.
2,4,40,6-Tetrahydroxy-3-methoxyphenyldeoxy-
37
benzoin (14).. A similar treatment described for 13 of
p-hydroxyphenylacetonitrile (266 mg, 2 mmol) with
anhydrous 1,3,5-trihydroxy-2-methoxybenzene (312 mg,
2 mmol) afforded compound 14 as yellow needles. Fur-
ther purification was not necessary (380 mg, 66%). Mp
224–225 ꢁC (lit., 228 ꢁC). 1H NMR d: 3.59 (s, 3H,
3-OH), 4.22 (s, 2H, ArCH2), 5.91 (s, 1H, H-5), 6.67 (d,
2H, J = 8 Hz, H-30, 50), 7.01 (d, 2H, J = 8 Hz, H-20,
60), 9.21 (s, 1H, 40-OH), 10.37 (s, 1H, 4-OH), 11.54 (s,
1H, 2-OH), 12.50 (s, 1H, 6-OH). ESI-MS C15H15O6
[M+H]+ 291. Anal. Calcd for C15H14O6: C, 62.07; H,
4.86. Found: C, 62.11; H, 4.82.
4.5.17. Tectorigenin (20) and w-tectorigenin (18)..37
A
similar treatment described for 17 of compound 15
(203 mg, 0.7 mmol) in anhydrous DMF (1.6 mL) with
CH3SO2Cl (0.3 mL, 3 mmol) in anhydrous DMF
(0.7 mL) afforded a yellow precipitate. The precipitate
was separated and purified by a flash chromatography
with EtOAc–petroleum ether (1:1) to give two fractions.
The first fraction gave compound 18 as pale yellow nee-
dles (76 mg, 36%). Mp 230–232 ꢁC (lit., 228–230 ꢁC). 1H
NMR d: 3.75 (s, 1H, OCH3), 6.50 (s, 1H, H-6), 6.81 (d,
2H, J = 8 Hz, H-30, 50), 7.37 (d, 2H, J = 8 Hz, H-20, 60),
8.34 (s, 1H, H-2), 9.60 (s, 1H, 40-OH), 10.78 (s, 1H, 7-
OH), 13.06 (s, H, 5-OH). ESI-MS C16H13O6 [M+H]+
301. Anal. Calcd for C16H12O6: C, 64.00; H, 4.03.
Found: C, 63.96; H, 4.05. The second fraction gave com-
pound 19 as pale yellow needles (85 mg, 40%). Mp 241–
4.5.14. 4-(p-Hydroxyphenethyl)pyrogallol (15). NaBH4
(304 mg, 8 mmol) was added to a solution of pyrogallol
(260 mg, 1 mmol) in 1.22 M NaOH (1.64 mL, 2 mmol)
and water (5 mL), and the mixture was heated under
reflux for 3 h. After cooling, 5 M hydrochloric acid was
added to decompose the excess NaBH4 on an ice-water
bath. The mixture was extracted with EtOAc. After
removal of the solvent, the resulting residue was purified
over a silica gel column eluting with isopropanol–petro-
leum ether (1:4) to give compound 15 as yellowish oil
which was crystallized from 5 M hydrochloric acid (pale
brown needles, 210 mg, 85%). Mp 181–183 ꢁC (begin to
decompose above 160 ꢁC). 1H NMR d: 2.62 (s, 4H,
2ArCH2), 6.17 (d, 1H, J = 8 Hz, ArH-6), 6.30 (d, 1H,
J = 8 Hz, H-5), 6.64 (d, 2H, J = 8 Hz, H-30, 50), 6.97 (d,
2H, J = 8 Hz, H-20, 60), 8.04 (br s, 2H, 2,3-OH), 8.74
(s, 1H, 1-OH), 9.06 (s, 1H, 40-OH). ESI-MS C14H14O4Na
[M+Na]+ 269. Anal. Calcd for C14H14O4: C, 68.28; H,
5.73. Found: C, 68.23; H, 5.69.
1
243 ꢁC (lit., 240 ꢁC). H NMR d: 3.76 (s, 1H, OCH3),
6.31 (s, 1H, H-8), 6.81 (d, 2H, J = 8 Hz, H-30, 50), 7.37
(d, 2H, J = 8 Hz, H-20, 60), 8.41 (s, 1H, H-2), 9.60 (s,
1H, 40-OH), 10.83 (s, 1H, 7-OH), 12.65 (s, H, 5-OH).
ESI-MS C16H13O6 [M+H]+ 301. Anal. Calcd for
C16H12O6: C, 64.00; H, 4.03. Found: C, 64.05; H, 4.01.
4.5.15.
6-(1-Hydroxy-2-(4-methoxyphenyl)ethyl)-2,3-
Acknowledgment
dimethoxyphenol (16). Acetic acid (0.1 mL) is added with
cooling to NaBH4 (25 mg, 0.6 mmol) in 1 mL THF.
After the evolution of hydrogen has ceased (about 3 h)
compound 12 is added at room temperature with stir-
ring for 4 h. The reduction is interrupted by adding
1 mL of water, the mixture neutralized with aqueous
NaHCO3, and the reaction product isolated by extrac-
tion with EtOAc. After drying and evaporation, com-
pound 16 is afforded as pale yellow solid (83 mg,
91%). Mp 87–89 ꢁC. 1H NMR d: 2.60 (d · d, 1H,
J = 14 Hz, J = 8Hz ArCH2), 2.83 (d · d, 1H,
J = 14 Hz, J = 4Hz, ArCH2), 3.66 (s, 3H, 2-OCH3),
3.70 (s, 3H, 1-OCH3), 3.75 (s, 3H, 40-OCH3), 4.90 (q,
1H, Ar C(OH)H, J = 8 Hz, J = 4Hz), 6.46 (d, 1H,
J = 9 Hz, H-5), 6.79 (d, 2H, J = 9 Hz, H-30, 50), 6.95
(d, 1H, J = 9 Hz, H-6), 7.07 (d, 2H, H-20,60, J = 9 Hz),
8.76 (s, H, 3-OH). ESI-MS C17H19O4 [MꢀH2O+H]+
287. Anal. Calcd for C17H20O5: C, 67.09; H, 6.62.
Found: C, 667.11; H, 5.59.
The work was financed by Grant (Project 30672516)
from National Natural Science Foundation of China.
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