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S. Sato et al. / Carbohydrate Research 341 (2006) 964–970
3.5. 6,8-Di-C-b-D-glucopyranosylnaringenin (5)
5.29 (t, 1H, J 9.8 Hz, H-3000), 5.63 (t, 1H, J 9.8 Hz, H-
200), 5.93 (t, 1H, J 9.8 Hz, H-2000), (aglycone moiety)
2.32, 2.44, 2.49 (each s, 3H, ArOAc · 3), 2.84 (dd, 1H,
J 2.8, 16.8 Hz, H-3a), 3.01 (dd, 1H, J 14.1, 16.8 Hz,
H-3b), 5.78 (dd, 1H, J 2.8, 14.1 Hz, H-2), 7.22 (d, 2H,
J 8.8 Hz, H-20 and 60), 7.60 (d, 2H, J 8.8 Hz, H-30 and
50); FABMS (NBA, m/z) 1059 (M+H)+. Anal. Calcd
for C49H54O26Æ0.5H2O: C, 55.11; H, 5.19. Found: C,
54.99; H, 5.28.
Concd HCl (0.5 mL) was added to a solution of 3
(100 mg, 0.105 mmol) in 1 mL of MeOH. The solution
was refluxed for 15 min. After the disappearance of 3
by TLC, the reaction mixture was evaporated in vacuo,
EtOH was added to the residue and the solution was
again evaporated in vacuo to remove HCl. The residual
solid was dissolved in MeOH (5 mL) and 10% Pd–C
(20 mg) was added to the solution. [Caution! Pd–C can
cause MeOH to catch fire either before hydrogenation
or after.] The suspension was vigorously stirred under
an H2 atmosphere at room temperature for 1 h. The reac-
tion mixture was filtered through a Celite pad, which
was then washed with MeOH. The filtrate was evapo-
rated in vacuo to give 5 (61.3 mg, 98%) as a pale-yellow
solid: FTIR m (KBr) 3370, 2927, 2893, 1618, 1520, 1458,
20
3.6.2. Data for 50b. ½aꢀD ꢁ45.9 (c 1.19, CHCl3); natural
21
product,16 ½aꢀD ꢁ43.1 (c 1.48, CHCl3); FTIR m (KBr)
3446, 2941, 1780, 1755, 1699, 1602, 1373, 1228 cmꢁ1
;
1H NMR (CDCl3): d 1.71, 1.78, 1.81, 1.93, 2.04, 2.06
(each s, 3H, OAc · 6), 2.02 (s, 6H, OAc · 2), 3.61 (m,
1H, H-5000), 3.76 (m, 1H, H-500), 3.94 (d, 1H, J 12.0 Hz,
H-600a), 4.02 (dd, 1H, J 1.7, 12.4 Hz, H-6000a), 4.14 (dd,
1H, J 5.0, 12.4 Hz, H-6000b), 4.35 (d, 1H, J 9.8 Hz, H-
1000), 4.41 (dd, 1H, J 5.0, 12.0 Hz, H-600b), 4.64 (d, 1H,
J 9.8 Hz, H-100), 4.93 (t, 1H, J 9.8 Hz, H-4000), 5.12 (t,
1H, J 9.8 Hz, H-400), 5.26 (t, 1H, J 9.8 Hz, H-300), 5.28
(t, 1H, J 9.8 Hz, H-3000), 5.66 (t, 1H, J 9.8 Hz, H-200),
5.99 (t, 1H, J 9.8 Hz, H-2000), (aglycone moiety) 2.32,
2.43, 2.49 (each s, 3H, ArOAc · 3), 2.85 (dd, 1H, J
2.6, 16.2 Hz, H-3a), 3.11 (dd, 1H, J 14.5, 16.2 Hz, H-
3b), 5.57 (m, 1H, H-2); FABMS (NBA, m/z) 1059
(M+H)+. Anal. Calcd for C49H54O26Æ0.5H2O: C,
55.11; H, 5.19. Found: C, 55.00; H, 5.24.
1
1346, 1209, 1080 cmꢁ1; H NMR (CD3OD): d (aglycon
moiety) 2.80 (dd, 1H, J 3.0, 16.5 Hz, CH2), 3.11 (dd, 1H,
J 13.0, 16.5 Hz, CH2), 5.40 (dd, 1H, J 3.0, 13.0 Hz, H-2),
6.84 (d, 2H, J 8.5 Hz, p-substituted ArH · 2), 7.34 and
7.37 (each d, 1H, J 8.5 Hz, p-substituted ArH · 2),
9.25 (br s, 1H, ArOH), 12.74 and 12.77 (each s, 1H,
ArOH), (glucose moiety at 60 ꢁC) 3.32–3.53 (m, 6H),
3.71–3.97 (m, 6H), 4.82–4.91 (m, 2H); 13C NMR (Table
1); FABMS (glycerol, m/z) 597 (M+H)+. Anal. Calcd
for C27H30O15Æ2.5H2O: C, 50.54; H, 5.81. Found: C,
50.69; H, 5.51.
3.6. 5,7,40-Tri-O-acetyl-6,8-di-C-(octa-O-acetyl-b-D-
3.7. 5,7,40-Tri-O-acetyl-6,8-di-C-(octa-O-acetyl-b-D-
glucopyranosyl)naringenin (50a,b)
glucopyranosyl)apigenin (60)
A solution of 5 (50 mg, 0.084 mmol) in Ac2O (1 mL) and
pyridine (1 mL) was stirred overnight at room tempera-
ture. The reaction mixture was poured into water
(50 mL), the solution stirred for 0.5 h and then extracted
twice with AcOEt. The combined extracts were washed
with H2O, dried over anhydrous Na2SO4, and then
evaporated in vacuo. The residue was purified by
column chromatography on silica gel (2:1 and 1:1
CHCl3–AcOEt) to give 50a (39 mg, 44%), a mixture of
50a and 50b (17 mg, 19%), and 50b (32 mg, 36%), as
pale-yellow amorphous solids.
A
solution of flavanone acetate 50ab (100 mg,
0.0945 mmol) and DDQ (86 mg, 0.38 mmol) in chloro-
benzene (1.5 mL) was refluxed for 1 day. The reaction
mixture was evaporated in vacuo to afford a residue,
which was acetylated with Ac2O (2 mL) and pyridine
(2 mL) at room temperature overnight. The reaction
mixture was poured into ice-cold water (20 mL), and
the resulting mixture was stirred for 0.5 h and extracted
twice with AcOEt. The combined extracts were washed
with H2O and satd aq NaCl, dried over anhyd Na2SO4,
and then evaporated in vacuo. The residue was purified
by column chromatography on silica gel (1:2 hexane–
AcOEt) to give 60 (55.9 mg, 56%) as a white powder,
and the recovery of 50ab (30.0 mg, 30%) as a pale-yellow
powder. The recovered 50ab was then reoxidized using
the same procedure as described above.
21
3.6.1. Data for 50a. ½aꢀD ꢁ38.0 (c 1.11, CHCl3); natural
21
product,16 ½aꢀD ꢁ40.8 (c 2.05, CHCl3); FTIR m (KBr)
3446, 2943, 1780, 1755, 1697, 1604, 1369, 1230 cmꢁ1
;
1H NMR (CDCl3): d (glucose moiety) 1.78, 1.90, 1.96,
2.02, 2.03, 2.04, 2.05, 2.06 (each s, 3H, OAc · 8), 3.65
(ddd, 1H, J 2.1, 4.9, 9.8 Hz, H-5000), 3.77 (ddd, 1H,
J 1.7, 4.9, 9.8 Hz, H-500), 3.94 (dd, 1H, J 1.7, 12.8 Hz,
H-600a), 4.15 (dd, 1H, J 2.1, 12.4 Hz, H-6000a), 4.24 (dd,
1H, J 4.9, 12.4 Hz, H-6000b), 4.30 (dd, 1H, J 4.9,
12.8 Hz, H-600b), 4.35 (d, 1H, J 9.8 Hz, H-1000), 4.70 (br
d, 1H, J 9.8 Hz, H-100), 5.02 (t, J 9.8 Hz, H-4000), 5.12
(t, 1H, J 9.8 Hz, H-400), 5.27 (t, 1H, J 9.8 Hz, H-300),
21
3.7.1. Data for 60. White solid; ½aꢀD +18.5 (c 0.79,
CHCl3); FTIR m (KBr) 3435, 2939, 1780, 1755, 1652,
1604, 1369, 1230, 1037 cmꢁ1 1H NMR (CDCl3): d
;
1.75, 1.88, 1.92, 1.99, 2.02, 2.05, 2.06, 2.10 (each s, 3H,
OAc · 8), 2.35, 2.49, 2.55 (each s, 3H, ArOAc · 3),
3.75 (ddd, 1H, J 1.7, 4.7, 9.8 Hz, H-500), 3.81 (ddd, 1H,
J 1.3, 4.0, 9.8 Hz, H-5000), 3.95 (dd, 1H, J 1.7, 12.8 Hz,