Protopine
Protopine is an alkaloid occurring in opium poppy, Corydalis tubers and other plants of the family papaveraceae, like Fumaria officinalis. Protopine is metabolically derived from the benzylisoquinoline alkaloid berberine bridge enzyme to -cheilanthifoline synthase/CYP719A25 to -stylopine synthase/CYP719A20 to -tetrahydroprotoberberine N-methyltransferase to N''-methylstylopine hydroxylase to protopine.
It has been found to inhibit histamine H1 receptors and platelet aggregation, and acts as an analgesic.
