2', 3', 4', 5, 5', 6, 7, 8-Octamethoxy-(Ia) and 2', 3', 4', 5, 5', 6, 7-heptamethoxyflavone (IIa) and their position isomers substituted with tetramethoxyl groups in ring B were synthesized to confirm the structures of agehoustin A and agehoustin B isolated from Ageratum houstonianum. The characteristics of the synthesized flavones were investigated by spectroscopic methods.
