The known alkaloids (-)-stylopine, (-)-canadine, (+/-)-sinactine, (+)-nantenine, (+)-bulbocapnine, protopine, (-)-isocorydine, (-)-domesticine, alpha-allocryptopine and berberine were found in a mixture of alkaloids from Corydalis slivenensis (Papaveraceae), growing in Bulgaria. Dehydronantenine,