ABSTRACT
The opioid drugs, such as morphine, codeine, methadone, oxycodone, and many others, are derived from or are analogs of extracts of compounds isolated from the opium poppy (Papaver somniferum). The naturally occurring exogenous opioids (e.g., morphine and codeine) and endogenous opioids (e.g., the endorphins and enkephalins) co-evolved (see Chapter 1) the ability to produce a great variety of biological effects, some benecial and some not. For a long time, it was thought that the poppy was nature’s sole source of opioid compounds. However, it now appears that biological diversity has evolved an alternative source of opioid compounds, and that is the subject of this book.
