Two new isoflavonoids from the roots of Dalbergia congesta (Grah)

A systematic examination of the roots of Dalbergia congesta, yielded a new oligomeric isoflavonoid (1), a new tetramethoxy isoflavone (2) along with two known compounds, an isoflavone dalspinin (3) and a benzophenone, cearoin (4). On the basis of chemical and spectral evidences, compounds 1 and 2 were determined to be 5,7-dihydroxy-6,4'-dimethoxy-6'[2''-hydroxy-2''(2''',5'''-dimethoxy neoflavonyl) ethenyl] isoflavone (dalcongestin) and 5,7-dihydroxy-2',3',5',6'-tetramethoxy isoflavone, respectively.