A new 4,5-dioxoaporphine, named corydione, was isolated from the whole herb of Corydalis bulbosa (L.) Dc (Papaveraceae), together with dehydronantenine, (-)-stylopine, (+)-bicuculline, (-)-adlumidine, (+)-nantenine, (+)-bulbocapnine, protopine (-)-domesticine, (+)-corydine, predicentrine,