It contains many alkaloids such as Protopine Rhoeadine which are the predominant constituents along with smaller amounts of Stylopine, Cryptopine, Sanguinarine, Magnoflorine, |
Papaverrubine D (aka
Papaverrubine E and the tertiary bases IsoThebaine,
Scoulerine and Corytuberine as well as a new quaternary alkaloid
Papaverrubine B and
Muramine were also detected.
Scoulerine (aka Discretamine and Aequaline) is derived from Reticuline and a precursor to Berberine, all BenzylIsoQuinolines. It is found in many plants including Opium Poppy and some plants belonging to the non-native Erythrina genus which is in the Pea Family Fabaceae and in the non-native plant Croton flavens, which belongs to the Euphorbia family.
Cryptopine (as well as CryptoCavine [an isomer of Cryptopine] and AlloCryptopine) are widely distributed in the Fumaricaceae division of Papaveraceae. It is toxic. It has a striking colour reaction when a trace of it in Acetic Acid is then treated with Sulfuric Acid: it turns reddish-violet, which persists for several hours before gradually changing to a dirty blue. All of the Protopine alkaloids behave similarly.
Muramine has a pseudonym called
CryptoPalmitine. Your Author has failed to find anything else about this molecule.
RHOEADINE group of ISOQUINOLINE ALKALOIDS
Rhoeadine is generally classified as an IsoQuinoline, albeit one with a 3-benzazepine entity, which is a 7-membered carbon ring containing a heterocyclic nitrogen atom, as do all three of the PapaverRubines depicted here. Despite the slight difference in the way it is drawn (in particular the 7-membered ring) they are all related. Rhoeadine is, apparently, unlike opium, a non-toxic sedative. Common Poppy, which contains rhoeadine, was used as a mild analgesic.
The PapaverRubines have just a hydrogen atom attached to the nitrogen rather than a methyl group of Rhoeadine. All other differences occur in one or both 5-membered rings at each extremity of Roeadine, which are broken (or not) in the PapaverRubines. The PapaverRubines are
N-norRhoeadines. The PapaverRubines have been known from Common Poppy since 1865, but only in the early 1960's was the correct structure ascertained. The PapverRubines (which have N-H) are renown for the deep-red colour when treated with a dilute mineral acid. (By contrast, all N-methyl alkaloids which includes Rhoeadine, when treated with concentrated sulfuric acid turn from red through brown to green).
The Rhoeadine alkaloids occur in many but not all species of Papaver and in some Mecanopsis species PapaverRubine A is the same as Rhoeadine apart from the N-methyl being replaced by NH.
It will be noticed that PapaverRubine B no longer has the 6-membered ring fused to the 7-membered ring: that link is broken creating an 11-membered ring.
When PapaverRubines or Rhoeodine are treated with a dilute mineral acid the molecule undergoes extensive rearrangement into the red inimium salt of that PapaverRubine. This shows the red inimium salt derived from PapaverRubine A. It is a Zwitterion, with a positive charge on the nitrogen atom because that atom has 4 bonds rather than the normal 3 of nitrogen. The 6-membered ring with the heterocylclic oxygen atom has completely disappeared and a new 5-membered carbon ring fused onto the 7-membered ring to share its nitrogen atom between them. It will attract a negative ion, such as chlorine to form the chloride salt. Your Author speculates whether this inimium salt may be responsible for the drying-to-red of the latex in some species of poppy. This red inimium salt has intense calorific value when burned.