O-Methyldeoxopunjabine, a Secobisbenzylisoquinoline Alkaloid Bearing an Aryl Methyl Group, and Three Other Secobisbenzylisoquinoline Alkaloids, O-Methylpunjabine, Secocepharanthine, and Dihydrosecocepharanthine, from Stephania Sasakii

Abstract

Two new secobisbenzylisoquinoline alkaloids, secocepharanthine (base J) (3) and O-methylpunjabine (base K) (4), were isolated from Stephania sasakii HAYATA (Menispermaceae). Their structures were established and the structures of two other alkaloids [base B (1) and base C (2)] were also established as dihydrosecocepharanthine (1) and O-methyldeoxopunjabine (2). In addition, two known bisbenzylisoquinoline alkaloids, obaberine (5) and thalrugosine (6), were newly isolated from the same plant.