In Sinomenium acutum , Menispermaceae, sinoacutine is the precursor of sinomenine, a compound epimeric to morphine. Hasubanonine-like alkaloids are known from Sinomenium and Stephania Menispermaceae. Although these alkaloids are similar in structure to morphine alkaloids, they have quite distinct biological properties. Another species, Papaver bracteatum contains thebaine. Opium is made by lacerating immature capsules of the plant.
Most codeine is prepared by methylation of morphine.
Heroin, the diacetyl derivative of morphine, is not naturally occurring. Although many have tried to produce morphine and related compounds in tissue culture or cell culture systems, the usual product is sanguinarine. Morphine suppresses some central nervous functions, but stimulates others. This alkaloid produces analgesia, drowsiness, changes in mood, and mental clouding. Analgesia occurs without loss of consciousness.