Eight new isoflavonoids, secundiflorols G-I and arizonicanols A-E, were isolated from the stem of Sophora secundiflora and the root of S. arizonica and S. gypsophila and the structures were determined by spectral analysis. The similarity of flavonoid occurrence was found in the three species. From the chemosystematic standpoint, the subgenus Styphnologbium seems to be composed of two chemical types (S. secundiflora, S. arizonica, and S. gypsophila vs S. japonica and S. affinis). (C) 1998 Elsevier Science Ltd. All rights reserved.