“…To date, the isolation of only five stephaoxocanes (1bϪf) has been reported, their source being plants of the Menispermaceae family employed in folk medicine. [6,7] Stephaoxocanidine (1b, isolated from Stephania cepharantha) and eletefine (1c, which occurs in Cissampelos glaberrima, better known as C. pareira), have fully unsaturated AB rings, whereas their congeners stephaoxocanine 1d, eccentricine 1e, and N-methyleccentricine 1f display dihydro and tetrahydro-substituted AB ring systems, respectively. Most noteworthy is the fact that the stephaoxocanes bear a close structural relationship to other tetracyclic isoquinoline derivatives, such as the tropoloisoquinolines grandirubrine 2a and imerubrine 2b, and the azafluoranthenes, exemplified by telitoxine 3a and imeluteine 3b.…”