Conrauinones A and B, Two New Isoflavones from Stem Bark of Millettia conraui1

Two new isoflavones, named conrauinones A (1) and B (2), have been isolated from the stem bark of Millettia conraui, in addition to known 5-methoxydurmillone. The structures of the new compounds were determined by spectroscopic analysis including 2D NMR techniques as 5,6,2'-trimethoxy-4',5'-(methylenedioxy)-2",2"-dimethylpyrano[5",6":7,8]isoflavone (1) and 6-methoxy-3',4'-(methylenedioxy)-7-O-[(E)-3",7"-dimethyl-7"-ol-2",5"-octadienyl]isoflavone (2).