Scoulerine, also known as discretamine and aequaline, is a

benzylisoquinoline Substitution of the heterocycle isoquinoline at the C1 position by a benzyl group provides 1‑benzylisoquinoline, the most widely examined of the numerous benzylisoquinoline structural isomers. The 1-benzylisoquinoline moiety can be identified ...

alkaloid Alkaloids are a class of basic BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Th ...

(BIA) that is derived directly from (''S'')-

reticuline Reticuline is a chemical compound found in a variety of plants including '' Lindera aggregata'', ''Annona squamosa'', and ''Ocotea fasciculata'' (also known as ''Ocotea duckei''). It is based on the benzylisoquinoline structure. Reticuline is o ...

through the action of

berberine bridge enzyme Berberine is a quaternary ammonium salt from the protoberberine group of benzylisoquinoline alkaloids found in such plants as ''Berberis vulgaris'' (barberry), ''Berberis aristata'' (tree turmeric), ''Mahonia aquifolium'' (Oregon grape), ''Hydras ...

. It is a precursor of other BIAs, notably

berberine Berberine is a quaternary ammonium salt from the protoberberine group of benzylisoquinoline alkaloids found in such plants as '' Berberis vulgaris'' (barberry), '' Berberis aristata'' (tree turmeric), ''Mahonia aquifolium'' (Oregon grape), '' H ...

noscapine Noscapine (also known as Narcotine, Nectodon, Nospen, Anarcotine and (archaic) Opiane) is a benzylisoquinoline alkaloid, of the phthalideisoquinoline structural subgroup, which has been isolated from numerous species of the family Papaveraceae ...

, (''S'')-

tetrahydropalmatine Tetrahydropalmatine (THP) is an isoquinoline alkaloid found in several different plant species, mainly in the genus ''Corydalis'' ( Yan Hu Suo), but also in other plants such as ''Stephania rotunda''. These plants have traditional uses in Chines ...

, and (''S'')-stylopine, as well as the alkaloids

protopine Protopine is an alkaloid occurring in opium poppy, ''Corydalis'' tubers and other plants of the family papaveraceae, like ''Fumaria officinalis''. Protopine is metabolically derived from the benzylisoquinoline alkaloid ''(S)''-Reticuline through a ...

, and

sanguinarine Sanguinarine is a polycyclic quaternary alkaloid. It is extracted from some plants, including the bloodroot plant, from whose taxonomic name, ''Sanguinaria canadensis,'' its name is drawn; the Mexican prickly poppy (''Argemone mexicana''); '' Che ...

. It is found in many plants, including

opium poppy ''Papaver somniferum'', commonly known as the opium poppy or breadseed poppy, is a species of flowering plant in the family Papaveraceae. It is the species of plant from which both opium and poppy seeds are derived and is also a valuable orname ...

, '' Croton flavens'', and certain plants in the genus ''

Erythrina ''Erythrina'' is a genus of plants in the pea family, Fabaceae. It contains about 130 species, which are distributed in tropical and subtropical regions worldwide. They are trees, with the larger species growing up to in height. The generic ...

''. Studies show that scoulerine is an antagonist ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and ...

'' at the α₂-

adrenoceptor The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta ...

, α_1D-

and

5-HT receptor 5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory ...

. It has also been found to be a GABA_A receptor agonist ''in vitro''.

References

{{reflist Isoquinolinoisoquinolines Natural opium alkaloids Phenols Catechol ethers Methoxy compounds