[Studies on flavonoids of Andrographis paniculata].

Objective: To study the flavonoids of the aerial parts of Andrographis paniculata.

Method: Twelve flavonoids from the 85% EtOH extract were isolated by the silica gel column, Sephadex LH-20 column, ODS column chromatography and HPLC, and their structures were identified by the spectal analyses and chemical evidences.

Result: The 12 compounds were obtained and identified as 7-O-methylwogonin (1), 7-O-methyldihydrowogonin (2), 5-hydroxy-7, 8, 2', 5'-tetramethoxy-flavone (3), skullcapflavone-2'-methoxylether (4), 5-hydroxy-7, 8, 2', 3'-tetramethoxyflavone (5), 5, 4'-dihydroxy-7, 8, 2', 3'-tetramethoxyflavone (6), dihydroskullcapflavone (7), 5, 7, 8-trimethoxydihydroflavone (8), 5, 2'-dihydroxy-7, 8-dimethoxyflvone (9), andrographidine C (10), 5, 7, 4'-trihydroxyflavone (11), 5, 7, 3', 4'-tetrahydroxyflavone (12).

Conclusion: Compound 6 is a new naturally occurring product isolated from A. paniculata, and compound 8, 11 and 12 are obtained for the first time from the Andrographis species.