This chapter describes new aporphine alkaloids, occurrence of known aporphines in plants, biogenesis, synthesis, pharmacologies and properties of aporphine alkaloids. The NMR spectrum of stesakine shows the presence of a methoxyl group, an N-methyl group, one methylenedioxy function, and three aromatic protons in addition to a hydroxyl proton. IR spectrum of arosonine exhibits the presence of a phenolic function and a highly conjugated carbonyl system. A strong hypsochromic shift is again observed in its UV spectrum on addition of acid. Some or part of the oxoaporphine isolated from plant sources may exist in nature as the corresponding N-metho salts, and such salts would then undergo easy N-demethylation upon chromatographic purification. Aporphine alkaloids are known to be derived from the corresponding phenolic tetrahydrobenzylisoquinolines by direct oxidative coupling or by the formation of dienone derivatives (proaporphines or proerythrinadienones), which then rearrange into aporphines through dienone–phenol or dienol–benzene rearrangements. © 1985, Elsevier Science & Technology. All rights reserved.