Synthesis of Talosin A and B, Two Bioactive Isoflavonoid Glycosides
at 0 ℃, was added diethylaminosulfur trifluoride
(DAST) (0.12 mL). The temperature was allowed to
warm to room temperature. After 2 h, the reaction was
quenched by saturated NaHCO3. The mixture was di-
luted with CH2Cl2 and washed with brine. The organic
layer was dried with anhydrous Na2SO4, filtered, and
concentrated. The residue was purified by silica gel
chromatography on [V(CH2Cl2)∶V(MeOH)=12∶1] to
NMR (DMSO-d6, 300 MHz): δ 12.92 (s, 1H), 10.95 (s,
1H), 8.46 (s, 1H), 8.00 (d, J=7.2 Hz, 2H), 7.90 (d, J=
7.8 Hz, 2H), 7.70—7.30 (m, 15H), 6.42 (d, J=2.1 Hz,
1H), 6.25 (d, J=1.8 Hz, 1H), 6.13 (s, 1H), 5.93 (t, J=
3.6 Hz, 1H), 5.69—5.65 (m, 2H), 4.61—4.54 (m, 1H),
1.20 (d, J=6.0 Hz, 3H); 13C NMR (DMSO-d6, 100
MHz) δ: 180.46, 166.30, 165.75, 164.75, 162.45, 158.06,
155.66, 155.13, 134.05, 130.81, 129.87, 129.78, 129.46,
129.20, 129.09, 129.02, 125.59, 122.20, 117.03, 104.92,
99.55, 96.59, 94.24, 69.68, 67.25, 67.00, 66.03, 16.56;
ESI-MS (m/z): 729.3 (M+H+ ), 751.2 (M+Na+ );
HRMS [ESI] calcd for C42H32O12Na+ 751.1786, found
751.1811.
afford
2,3,4-Tri-O-benzoyl-6-deoxy-L-talopyranosyl
fluoride (381 mg, α∶β=7∶1) as white solids.
2,3,4-Tri-O-benzoyl-6-deoxy-α-L-talopyranosyl flu-
1
oride: H NMR (CDCl3, 300 MHz) δ: 8.09—8.07 (m,
2H), 7.97—7.95 (m, 2H), 7.79 (dd, J=8.0, 1.2 Hz, 2H),
7.61—7.19 (m, 9H), 5.97 (s, 0.5H), 5.85 (s, 0.5H),
5.81—5.79 (m, 1H), 5.72 (d, J=4.0 Hz, 1H), 5.64—
5.63 (m, 1H), 4.62—4.57 (m, 1H), 1.40 (d, J=6.8 Hz,
3H); 13C NMR δ: 166.2, 165.9, 165.1, 133.4, 133.3,
133.2, 130.0, 129.8, 129.6, 129.2, 128.5, 128.4, 128.34,
128.32, 107.2 (105.0), 68.8, 67.9 (67.8), 66.2, 65.92
(65.89, 65.80), 16.3; 19F NMR δ: -136.97 (d, J=51.9
Hz); ESIMS for C27H23FO7 (m/z): 501 (M+Na+).
Genistein 4',7-di-O-(tri-O-benzoyl-6-deoxy-α-L-
1
talopyranoside) (14) [α]28 -74.2 (c 0.60, CHCl3); H
NMR (CDCl3, 300 MHz) Dδ: 12.86 (s, 1H), 8.12 (d, J=
7.8 Hz, 4H), 8.01 (d, J=8.4 Hz, 4H), 7.96 (s, 1H), 7.83
(d, J=7.5 Hz, 4H), 7.65—77.20 (m, 22H), 6.75 (d, J=
2.4 Hz, 1H), 6.67 (d, J=2.1 Hz, 1H), 6.02—76.00 (m,
1H), 5.97—75.96 (m, 2H), 5.92 (s, 1H), 5.75 (br s, 2H),
5.70 (br s, 2H), 4.54—74.47 (m, 2H), 1.36—71.33 (m,
6H); ESI-MS (m/z): 1187.2 (M+H+); HRMS [ESI]
cacld for C69H54O19Na+ 1209.3156, found 1209.3160.
Glycosylation of 13 with 8 following a procedure
similar to that for 5→9 afforded 14 in 96% yield.
2,3,4-Tri-O-benzoyl-6-deoxy-β-L-talopyranosyl flu-
1
oride: H NMR (CDCl3, 300 MHz) δ: 8.05—8.02 (m,
4H), 7.83—7.81 (m, 2H), 7.56—7.24 (m, 9H), 5.84—
5.83 (m, 1H), 5.77 (s, 0.5H), 5.70—5.68 (m, 1H), 5.64
(s, 0.5H), 5.62 (s, 1H), 4.25—4.19 (m, 1H), 1.53 (d, J=
6.8 Hz, 3H); 13C NMR δ: 166.1, 165.9, 165.3, 133.4,
133.34, 133.28, 130.1, 130.0, 129.8, 129.4, 129.3, 129.1,
128.41, 128.40, 128.34, 128.25, 105.9 (103.7), 70.5
(70.4), 68.2 (68.1), 67.8, 66.8 (66.6), 16.5; 19F NMR δ:
142.96 (d, J=50.1 Hz); ESIMS for C27H23FO7 (m/z):
501 (M+Na+).
Talosin B
Talosin B (2) was prepared from 14 following a
procedure similar to that for 9→1. Thus, treatment of 15
(37 mg, 0.045 mmol) with K2CO3 (19 mg, 0.14 mmol),
after chromatography on silica gel chromatography
[V(CH2Cl2)∶V(MeOH)=6∶1] gave 2 (15 mg, 59%)
as a white solid.1 [α]D28 -170.9 (c 0.40, MeOH), Lit.1b
[α]25 -41.0 (c 0.10, MeOH); 1H NMR (DMSO-d6, 300
MHDz) δ: 12.89 (s, 1H), 8.50 (s, 1H), 7.52 (d, J=8.7 Hz,
2H), 7.14 (d, J=8.7 Hz, 2H), 6.80 (s, 1H), 6.52 (s, 1H),
5.72 (s, 1H), 5.56 (s, 1H), 5.37—5.32 (m, 2H),
5.08—4.93 (m, 4H), 3.86—3.79 (m, 6H), 3.55 (s, 2H),
1.09 (d, J=6.3 Hz, 6H); 13C NMR (DMSO-d6, 100
MHz): δ 180.81, 162.24, 162.08, 157.65, 156.45, 155.56,
130.66, 124.57, 122.62, 116.76, 106.58, 100.39, 99.29,
99.25, 95.27, 72.59, 72.40, 70.62, 70.23, 68.87, 68.32,
65.65, 65.45, 17.13,+17.07; ESI-MS (m/z): 563.7 (M+
H+), 585.1 (M+Na ); HRMS [ESI] calcd for C27H30-
O13Na+585.1579, found 585.1596.
Glycosylation of 5,4',7-tri-O-trimethylsilylgenis-
tein (10) and 2,3,4-Tri-O-benzoyl-6-deoxy-L-talopy-
ranosyl fluoride (11) To a solution of 5,4',7-tri-O-
trimethylsilylgenistein (10) (60 mg, 0.12 mmol) and
2,3,4-tri-O-benzoyl-6-deoxy-L-talopyranosyl fluoride
(11) (187 mg, 0.39 mmol) in toluene (1.5 mL) at 0 ℃,
was added BF3•OEt2 (0.07 mL). The reaction was fol-
lowed by TLC. After 2 h, the mixture was quenched
with H2O, filtered by celite. The filtrate was washed
with NaHCO3 (aq.) and brine. The organic layer was
dried with anhydrous Na2SO4, filtered, and concentrated.
The residue was purified by silica gel chromatography
on [V(petroleum ether)∶V(CH2Cl2)∶V(ethyl acetate)
=6∶2∶1] to afford 12 (2 mg, 2%), 13 (43 mg, 48%)
and 14 (65 mg, 45%) as white solids.
References
Genistein 7-O-(tri-O-benzoyl-6-deoxy-α-L-talopy-
ranoside) (12) 1H NMR (DMSO-d6, 300 MHz) δ:
11.95 (s, 1H), 9.06 (s, 1H), 8.01 (d, J=7.5 Hz, 2H),
7.90 (d, J=7.5 Hz, 2H), 7.70—7.30 (m, 16H), 6.73 (s,
1H), 6.48 (s, 1H), 6.18 (s, 1H), 5.95—5.92 (m, 1H),
5.70—5.65 (m, 2H), 4.62—4.55 (m, 1H), 1.21 (d, J=
6.3 Hz, 3H); ESI-MS (m/z): 729.4 (M+H+), 751.+2
(M +Na + ); HRMS [ESI] calcd for C42H32O12Na
751.1786, found 751.1811.
1
(a) Yoon, T. M.; Kim, J. W.; Kim, J. G.; Kim, W. G.; Suh, J.
W. J. Antibiot. 2006, 59, 639.
(b) Kim, W. G.; Yoon, T. M.; Kwon, H. J.; Suh, J. W. J.
Antibiot. 2006, 59, 640.
2
3
Hwang, Y.; Kim, M.; Song, I.; Lim, J.; Park, B.; Yun, H.
Biotechnol. Lett. 2009, 31, 789.
(a) Zhu, C.; Peng, W.; Li, Y.; Han, X.; Yu, B. Carbohydr.
Res. 2006, 341, 1047.
(b) Peng, W.; Li, Y.; Zhu, C.; Han, X.; Yu, B. Carbohydr.
Res. 2005, 340, 1682.
Genistein 4'-O-(tri-O-benzoyl-6-deoxy-α-L-talo-
1
pyranoside) (13) [α]27 -84.5 (c 0.59, CHCl3); H
D
Chin. J. Chem. 2010, 28, 1725— 1730
© 2010 SIOC, CAS, Shanghai, & WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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