Phenolic constituents of the roots of Sophora flavescens

From the roots of Sophora flavescens collected in Taiwan, four new prenylflavonoids, sophoraflavanone K (1), sophoraflavanone L (2), 8-lavandulylkaempferol (3), and cyclokuraridin (4), a new arylbenzofuran, 2-(2,4-dihydroxy-5- prenylphenyl)-5,6-methylenedioxybenzofuran (5), and a new prenyldibenzoyl derivative, sophoradione (6), were isolated. The structures of 1-6 were determined by spectroscopic data analysis. Compounds 2-6 were evaluated for cytotoxic activity against the KB epidermoid carcinoma cell line.