Studies on the constituents of Sophora species -: Part 26 -: Four isoflavanones from roots of Sophora tetraptera

Four new isoflavanones, tetrapterols F-I, were isolated from roots of Sophora tetraptera in addition to seven known flavonoids, lupinifolin, 8-O-methylretusin, 5,7,4'-trihydroxy-6,3'-di(gamma,gamma-dimethylallyl)isoflavone, (-)-maackiain, sophoracarpan A, medicagol and 2-(2,4-dihydroxyphenyl)-5,6-methylenedioxybenzofuran The structure of the new isoflavanones was determined to be 3,5,7-trihydroxy-2'-methoxy-8-gamma,gamma-dimethylallyl-6''',6'''-dimethylpyrano[2''',3''':4',3']isoflavanone(tetrapterol F), 5,7,2',4'-tetrahydroxy-6,5'-di(gamma,gamma-dimethylallyl)isoflavanone(tetrapterol G), 5,7,2'-trihydroxy-4'-methoxy-8,5'-di(gamma,gamma-dimethylallyl)isoflavanone(tetrapterol H) and 7,4'-dihydroxy-6,3'-di(gamma,gamma-dimethylallyl)isoflavanone (tetrapterol I) by means of spectroscopic analysis. (C) 1998 Elsevier Science Ltd. All rights reserved.