Aporphine alkaloids and their reversal activity of multidrug resistance (MDR) from the stems and rhizomes of Sinomenium acutum.

Chromatographic separation of the MeOH extract from the stems and rhizomes of Sinomemium acutum led to the isolation of nine alkaloids and a lignan. Their structures were determined to be dauriporphine (1), bianfugecine (2), dauriporphinoline (3), menisporphine (4), (-)-syringaresinol (5), N-feruloyltyramine (6), acutumine (7), dauricumine (8), sinomenine (9), and magnoflorine (10) by spectroscopic means. These compounds were examined for their P-gp mediated MDR reversal activity in human cancer cells. Compound 1 showed the most potent P-gp MDR inhibition activity with an ED50 value 0.03 microg/mL and 0.00010 microg/mL in the MES-SA/DX5 and HCT15 cells, respectively.