What is "protopine"

Protopine \Pro"to*pine\, n. [Proto- + opium.] (Chem.) An alkaloid found in opium in small quantities, and extracted as a white crystalline substance.

n. (context biochemistry English) A benzylisoquinoline alkaloid occurring in plants of the ''Papaveraceae'' family that acts as an opioid analgesic.

Protopine is a benzylisoquinoline alkaloid occurring in opium poppy, Corydalis tubers and other plants of the family papaveraceae, like Fumaria officinalis. It has been found to inhibit histamine H1 receptors and platelet aggregation, and acts as an analgesic.