Flavonoids isolated from Draconis Resina.

One new chalcone, 4,6-dihydroxy-2-methoxy-3-methyldihydrochalcone (4), together with four known compounds, dammaradienol (1), (-)-5-methoxyflavan-7-ol (2), 5-methoxy-6-methyl-2-phenyl-7H-chromen-7-one (3), and dracorhodin (5), were isolated from Draconis Resina. The structures of these compounds were determined by spectral methods. Among these five compounds, compounds 1, 2, and 3 exhibited cytotoxicity against KB and HepG2 cells.