Labrandine: A new pentacyclic proaporphine alkaloid from Roemeria hybrida

The pentacyclic phenolic proaporphine (-)-labrandine (1) has been isolated from Turkish Roemeria hybrida (L.) DC. (Papaveraceae). O-Methylation furnished (-)-misramine (2) which is also present in the plant. Acetylation of 1 afforded (-)-2,10-diacetyllabrandine (3), and selective deacetylation of the latter provided (-)-10-acetyllabrandine (4). © 1990.