Overview
Opiates belong to the large biosynthetic group of benzylisoquinoline alkaloids, and are so named because they are naturally-occurring alkaloids found in the opium poppy. The major psychoactive opiates are morphine, codeine, and thebaine. Papaverine, noscapine, and approximately 24 other alkaloids are also present in opium but have little to no effect on the human central nervous system, and as such are not considered to be opiates. Semi-synthetic opioids such as hydrocodone, hydromorphone, oxycodone, and oxymorphone, while derived from opiates, are not opiates themselves.
While the full synthesis of opiates from naphthoquinone (Gates synthesis) or from other simple organic starting materials is possible, they are tedious and uneconomical processes. Therefore, most of the opiate-type analgesics in use today are either directly extracted from Papaver somniferum or synthesized from the natural opiates, mainly from thebaine.
Read more about this topic: Opiate