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 Sopho ra tetraptera in addition to seven known flavonoids, lupinifolin, 8-O-methy lretusin, 5,7,4'-trihydroxy-6,3'-di(gamma,gamma-dimethylallyl)isoflavone, ( -)-maackiain, sophoracarpan A, medicagol and 2-(2,4-dihydroxyphenyl)-5,6-me thylenedioxybenzofuran The structure of the new isoflavanones was determine d to be 3,5,7-trihydroxy-2'-methoxy-8-gamma,gamma-dimethylallyl-6''',6'''-d imethylpyrano[2''',3''':4',3']isoflavanone(tetrapterol F), 5,7,2',4'-tetrah ydroxy-6,5'-di(gamma,gamma-dimethylallyl)isoflavanone(tetrapterol G), 5,7,2 '-trihydroxy-4'-methoxy-8,5'-di(gamma,gamma-dimethylallyl)isoflavanone(tetr apterol H) and 7,4'-dihydroxy-6,3'-di(gamma,gamma-dimethylallyl)isoflavanon e (tetrapterol I) by means of spectroscopic analysis. (C) 1998 Elsevier Sci ence Ltd. All rights reserved.