Two new isoflavonoids, 7-hydroxy-6,4'-dimethoxy-isoflavonequinone (1) and 2'-hydroxy-6,4',6' ',4' ''-tetramethoxy-[7-O-7' ']-bisisoflavone (2), and seven other known flavonoids, 3-hydroxy-9-methoxypterocarpan (medicarpin), 3,10-dihydroxy-9-methoxypterocarpan, 3,9-dimethoxypterocarpan