New 2′-oxygenated flavonoids from Andrographis affinis

Three new T-oxygenated flavonoids, (2S)-5,7,2',3',4'-pentamethoxyflavanone (1), 5-hydroxy-7,8,2',5'-tetramethoxyflavone (2), and echioidinin 2'-O-beta-D-(6-O-acetyl) glucopyranoside (3), together with four known flavonoids, 7-O-methyldihydrowogonin, 7-0-methylwogonin, skullcapflavone I 2'-methyl ether, and skullcapflavone I, and two diterpenoids, andrograpanin and 14-deoxy-11,12-didehydroandrographolide, were isolated from the whole plant of Andrographis affinis. The structures were elucidated by spectral and chemical studies.