Secondary metabolites from Andrographis paniculata

Two new flavonoid glycosides, 5-hydroxy-7,8-dimethoxy (2R)-flavanone-5-O- β-D-glucopyranoside (1) and 5-hydroxy-7,8,2′,5′-tetramethoxy- flavone-5-O-β-D-glucopyranoside (2), and a new diterpenoid, andrographic acid (3), along with andrographidine A (4) were isolated from Andrographis paniculata, and their structures were determined on the basis of physicochemical and spectroscopic analysis. Compound 3 was evaluated for cytotoxicity to KB cells along with andrographolide, isoandrographolide, neoandrographolide and 14-deoxy-11,12-didehydroandrographolide obtained from A. paniculata in the present study. Cytotoxicity was observed for andrographolide and isoandrographolide with ED₅₀ values of 6.5 and 5.1 μg/ml, respectively.