Morphine (named after Morpheus, Greek god of dreams) is the major alkaloid present in opium. Opium is the dried sap of the unripe seed capsule of the poppy Papaver somniferum and its medical properties have been known since ancient times. Morphine is an analgesic, a substance that relieves pain without causing unconciousness. It was first extracted in pure form from opium in 1805, and was used extensively for pain relief on the battlefields of the American Civil War, largely as this war coincided with the invention of the hypodermic syringe. Its molecular structure was not correctly established until 1925, and it was first successfully synthesised in 1952/
Problems associated with morphine include addiction, nausea and depressed breathing and heart rate that can be fatal in the young or severely debilitated.
Acetylation with acetic anhydride produces the diacetyl derivative heroin. Heroin is also a good analgesic with less of a respiratory depression effect than morphine, but is far more addictive. Partial methylation of morphine, however, produces codeine, useful as an anti-coughing agent, althout it is only ten percent as effective an analgesic as morpheine.
Methadone retains the carbon ring structure of morphine but is no longer heterocyclic. It was synthesised by the Germans during WWII when supplies of natural morphine were short. It is used in substitutive therapy for heroin addiction, but methadone too is also addictive.