Prenylisoflavone derivatives from the roots of Hedysarum scoparium

Four new prenylisoflavone derivatives, namely, 5-hydroxy-4'-methoxy-8-prenyl-2''-hydroxyisopropyldihydrofurano[4,5:6,7]-isoflavone (1), 5-hydroxy-4'-methoxy-6-prenyl-2'''-hydroxyisopropyldihydrofurano[4,5:8,7]-isoflavone (2), 5-hydroxy-4'-methoxy-8-prenyl-1'',2''-peroxyl-3'',3''-dimethyldihydropyrano[5,6:6,7]-isoflavone (3), and 5-hydroxy-4'-methoxy-6-prenyl-1''',2'''-peroxyl-3''',3'''-dimethyldihydropyrano[5,6:8,7]-isoflavone (4), together with three known ones 5-7, were isolated from the roots of Hedysarum scoparium. Their structures were established by means of detailed spectroscopic analysis (IR, EI- or HR-ESI-MS as well as 1D- and 2D-NMR), and by comparison of their spectroscopic data with those reported for structurally related compounds.