13111-57-4Relevant articles and documents
ISOFLAVONES FROM THE GALL AND WOOD OF WISTERIA BRACHYBOTRYS
Kaneko, Michiko,Nakata, Hiroyuki,Takada, Fukiko,Matsumara, Masako,Kitagawa, Chiyo,et al.
, p. 267 - 270 (1988)
Two new isoflavones, 6-methoxy-7,8,4'-trihydroxyisoflavone and isotectorigenin 7-O-β-D-glucopyranoside, were isolated from the gall and wood of Wisteria brachybotrys, together with 15 known isoflavonoids.Key Word Index - Wisteria brachybotrys; Leguminosae; isoflavonoid; isoflavone glucoside; 6-methoxy-7,8,4'-trihydroxyisoflavone; isotectorigenin 7-O-β-D-glucopyranoside.
Efficient method for the synthesis of tectorigenin
Xiao, Zhu-Ping,Li, Huan-Qiu,Xue, Jia-Yu,Shi, Lei,Zhu, Hai-Liang
, p. 525 - 529 (2008/04/12)
Tectorigenin, isolated from the rhizomes of Belamcanda chinensis, shows a wide variety of biological activities. The interest in its biological activities has been matched by a corresponding interest in its synthesis. We herein reported a convenient synth
Studies of the selective O-Alkylation and dealkylation of flavonoids. XXIV. A convenient method for synthesizing 6- and 8-methoxylated 5,7- dihydroxyisoflavones
Horie, Tokunaru,Shibata, Kenichi,Yamashita, Kazuyo,Fujii, Kenichi,Tsukayama, Masao,Ohtsuru, Yoshizumi
, p. 222 - 230 (2007/10/03)
2',4'-Bis(benzyloxy)-3',6'-dimethoxychalcones (5), which were obtained from the dibenzyl ether of 2,4-dihydroxy-3,6-dimethoxyacetophenone (3), were oxidatively rearranged with thallium (III) nitrate in methanol and the resultant products were converted into 7-hydroxy-5,8-dimethoxyisoflavones (8) by hydrogenolysis, followed by cyclization. The isoflavones were quantitatively demethylated to 5,7-dihydroxy-8-methoxyisoflavones (2) via their acetates. The isomeric 5,7-dihydroxy-6-methoxyisoflavones (1) were also synthesized from the chalcones, obtained from 2,3-dimethoxy- (16) or 2- isopropoxy-3-methoxy-4,6-bis(benzyloxy)acetophenones (21), by a similar method. On the other hand, the isoflavones with two hydroxy groups at the 2'- and 4'-positions were easily synthesized by the following method. Treatment of the rearranged product from 2,2',4,4'-tetrakis(benzyloxy)-3'6'- dimethoxychalcone (5f) with hydrochloric acid (HCl) in acetic acid afforded 2',4',7-tris(benzyloxy)-5,8-dimethoxyisoflavone (10f). The 5-methoxy group in the isoflavone was quantitatively cleaved to give the corresponding 5- hydroxyisoflavone (11f), which was isomerized to 2',4',7-tris(benzyloxy)-5- hydroxy-6-methoxyisoflavone (25f) in the presence of anhydrous potassium carbonate. Hydrogenolysis of the two 5-hydroxyisoflavones proceeded smoothly to give 2',4',5,7-tetrahydroxy-8-(2f) and 6-methoxyisoflavones (1f), respectively. The 13C-NMR spectra of these isoflavones supported the proposed structures of polyhydroxyisoflavones. The proposed structures of two natural isoflavones were revised.