The aporphine alkaloids make up a large group including at the present time about 250 alkaloids isolated from plants of 20 families. Plants of the families Annonaceae and laura- ceae are the richest in these alkaloids. All aporphine alkaloids are based on the skeleton I [i] and consist of di-, tri-, tetra-, penta-, and hexasubstituted derivatives, the substitu- ... , ~.,~B.IN -RR=H; CH,, GQCH, ~T c 16" .o~..-+,,,JT ... The structures of the aporphine alkaloids have been ...