STUDIES ON THE CHEMICAL CONSTITUENTS OF MENISPERMUM DAURICUM DC.

Three new oxoisoaporphine-type alkaloids were isolated from the ethanolic extract of the rhizoma of Menispermum dauricum DC. The structures of the three alkaloids I, II and III were elucidated as 5.9-dimethoxy-7H-dibenzo (de, h) quinolin-7-one (named bianfugecine), 5,6-methylenedioxy-9-methoxy-7H-dibenzo (de, h) quinolin-7-one (named bianfugedine), and 4, 5,6,9-tetramethoxy-7H-dibenzo (de, h) quinolin-7-one (named bianfugenine), respectively. The present paper is the second report on the natural occurrence of this:new type of oxoisoaporphine alkaloids.