The method is to extract from the crushed plant with diluted sulfuric acid, which is a stronger acid than meconic acid, but not so strong to react with alkaloid molecules. The extraction is performed in many steps (one amount of crushed plant is extracted at least six to ten times, so practically every alkaloid goes into the solution). From the solution obtained at the last extraction step, the alkaloids are precipitated by either ammonium hydroxide or sodium carbonate. The last step is purifying and separating morphine from other opium alkaloids. The somewhat similar Gregory process was developed in the United Kingdom during the Second World War, which begins with stewing the entire plant, in most cases save the roots and leaves, in plain or mildly acidified water, then proceeding through steps of concentration, extraction, and purification of alkaloids. Other methods of processing "poppy straw" (i.e., dried pods and stalks) use steam, one or more of several types of alcohol, or other organic solvents. The poppy straw methods predominate in Continental Europe and the British Commonwealth, with the latex method in most common use in India. The latex method can involve either vertical or horizontal slicing of the unripe pods with a two-to five-bladed knife with a guard developed specifically for this purpose to the depth of a fraction of a millimetre and scoring of the pods can be done up to five times.
Occurrence of morphine in other Papaverales and Papaveraceae, as well as in some species of hops and mulberry trees has not been confirmed. Morphine is produced most predominantly early in the life cycle of the plant. Past the optimum point for extraction, various processes in the plant produce codeine, thebaine, and in some cases negligible amounts of hydromorphone, dihydromorphine, dihydrocodeine, tetrahydro-thebaine, and hydrocodone (these compounds are rather synthesized from thebaine and oripavine). In the brain of mammals, morphine is detectable in trace steady-state concentrations. The human body also produces endorphins, which are chemically related endogenous opioid peptides that function as neuropeptides and have similar effects to morphine. Human biosynthesis
Morphine is an endogenous opioid in humans that can be synthesized by and released from various human cells, including white blood cells. CYP2D6, a cytochrome P450 isoenzyme, catalyzes the biosynthesis of morphine from codeine and dopamine from tyramine along the biosynthetic pathway of morphine in humans. The morphine biosynthetic pathway in humans occurs as follows:L-tyrosine → para-tyramine or L-DOPA → dopamine → (S)-norlaudanosoline → (S)-reticuline → 1,2-dehydroretinulinium → (R)-reticuline → salutaridine → salutaridinol → thebaine → neopinone → codeinone → codeine → morphine (S)-Norlaudanosoline (also known as tetrahydropapaveroline) can also be synthesized from 3,4-dihydroxyphenylacetaldehyde (DOPAL), a metabolite of L-DOPA and dopamine. Urinary concentrations of endogenous codeine and morphine have been found to significantly increase in individuals taking L-DOPA for the treatment of Parkinsons disease. Biosynthesis in the opium poppy
Morphine is biosynthesized in the opium poppy from the tetrahydroisoquinoline reticuline. It is converted into salutaridine, thebaine, and oripavine.