Alkaloids with aporphin skeleton from Stephania dielsiana Y.C.Wu of Vietnam

From the tube of Stephania dielsiana (Menispermaceae) collected in Mai Chau-Hoa Binh province, three alkaloids dehydrostesakine (LO3C), 1,2-methylendioxy- 8,9-dimethoxy-7-oxodibenzo quinoline (oxocrebanin) (LO5B), and 1,2-methylendioxy-8-methoxy-7-oxodibenzo-quinoline have been isolated and charaterized by spectroscopic analyses (mainly by 1D and 2D NMR). Among them, the 1,2-methylendioxy-8-methoxy-7-oxodiben-zoquinoline is a new compound