Tropane alkaloids are a class of bicyclic .2.1

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of simila ...

s and

secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norma ...

s that contain a

tropane Tropane is a nitrogenous bicyclic organic compound. It is mainly known for the other alkaloids derived from it, which include atropine and cocaine, among others. Tropane alkaloids occur in plants of the families Erythroxylaceae (including coca) ...

ring in their

chemical structure A chemical structure determination includes a chemist's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target molecule or other solid. Molecular geometry refers to the spatial arrangement of ...

. Tropane alkaloids occur naturally in many members of the plant family

Solanaceae The Solanaceae , or nightshades, are a family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spices, weeds, and or ...

. Certain tropane alkaloids such as

cocaine Cocaine (from , from , ultimately from Quechua: ''kúka'') is a central nervous system (CNS) stimulant mainly used recreationally for its euphoric effects. It is primarily obtained from the leaves of two Coca species native to South Am ...

and

scopolamine Scopolamine, also known as hyoscine, or Devil's Breath, is a natural or synthetically produced tropane alkaloid and anticholinergic drug that is formally used as a medication for treating motion sickness and postoperative nausea and vomi ...

are notorious for their psychoactive effects, related usage and cultural associations. Particular tropane alkaloids such as these have pharmacological properties and can act as

anticholinergics Anticholinergics (anticholinergic agents) are substances that block the action of the neurotransmitter called acetylcholine (ACh) at synapses in the central and peripheral nervous system. These agents inhibit the parasympathetic nervous sys ...

stimulants Stimulants (also often referred to as psychostimulants or colloquially as uppers) is an overarching term that covers many drugs including those that increase activity of the central nervous system and the body, drugs that are pleasurable and inv ...

Classification

Anticholinergics

Anticholinergic drugs and

deliriant Deliriants are a subclass of hallucinogen. The term was coined in the early 1980s to distinguish these drugs from psychedelics and dissociatives such as LSD and ketamine, respectively, due to their primary effect of causing delirium, as oppose ...

s: *

Atropine Atropine is a tropane alkaloid and anticholinergic medication used to treat certain types of nerve agent and pesticide poisonings as well as some types of slow heart rate, and to decrease saliva production during surgery. It is typically given ...

racemic In chemistry, a racemic mixture, or racemate (), is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as racemates. ...

hyoscyamine, from the deadly nightshade (''

Atropa belladonna ''Atropa belladonna'', commonly known as belladonna or deadly nightshade, is a toxic perennial herbaceous plant in the nightshade family Solanaceae, which also includes tomatoes, potatoes, and eggplant (aubergine). It is native to Europe, ...

'') *

Hyoscyamine Hyoscyamine (also known as daturine or duboisine) is a naturally occurring tropane alkaloid and plant toxin. It is a secondary metabolite found in certain plants of the family Solanaceae, including henbane, mandrake, angel's trumpets, jims ...

, the ''levo''-

isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Is ...

of atropine, from henbane (''

Hyoscyamus niger ''Hyoscyamus niger'', commonly known as henbane, black henbane, or stinking nightshade, is a poisonous plant in the nightshade family Solanaceae. It is native to temperate Europe and Siberia, and naturalised in Great Britain and Ireland. Histor ...

''), mandrake (''

Mandragora officinarum ''Mandragora officinarum'' is the type species of the plant genus '' Mandragora'' in the nightshade family Solanaceae. It is often known as mandrake, although this name is also used for other plants. , sources differed significantly in the specie ...

'') and the sorcerers' tree ('' Latua pubiflora''). *

Scopolamine Scopolamine, also known as hyoscine, or Devil's Breath, is a natural or synthetically produced tropane alkaloid and anticholinergic drug that is formally used as a medication for treating motion sickness and postoperative nausea and vomi ...

, from henbane and ''

Datura ''Datura'' is a genus of nine species of highly poisonous, vespertine-flowering plants belonging to the nightshade family Solanaceae. They are commonly known as thornapples or jimsonweeds, but are also known as devil's trumpets (not to be co ...

'' species (Jimson weed) All three

acetylcholine Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Par ...

-inhibiting chemicals can also be found in the leaves, stems, and flowers in varying, unknown amounts in ''

Brugmansia ''Brugmansia'' is a genus of seven species of flowering plants in the nightshade family Solanaceae. They are woody trees or shrubs, with pendulous flowers, and have no spines on their fruit. Their large, fragrant flowers give them their common n ...

'' (angel trumpets), a relative of ''

''. The same is also true of many other plants belonging to subfamily

Solanoideae Solanoideae is a subfamily of the flowering plant family Solanaceae, and is sister to the subfamily Nicotianoideae. Within Solanaceae, Solanoideae contains some of the most economically important genera and species, such as the tomato (''Solanum l ...

of the

, the alkaloids being concentrated particularly in the leaves and seeds. However, the concentration of alkaloids can vary greatly, even from leaf to leaf and seed to seed.Eich, Prof. Dr. Eckhart, 2008, ''Solanaceae and Convolvulaceae: Secondary Metabolites - Biosynthesis, Chemotaxonomy, Biological and Economic Significance (A Handbook)'' pub. Springer-Verlag Berlin Heidelberg, .

Stimulants

Stimulant Stimulants (also often referred to as psychostimulants or colloquially as uppers) is an overarching term that covers many drugs including those that increase activity of the central nervous system and the body, drugs that are pleasurable and inv ...

s and cocaine-related alkaloids: *

Cocaine Cocaine (from , from , ultimately from Quechua: ''kúka'') is a central nervous system (CNS) stimulant mainly used recreationally for its euphoric effects. It is primarily obtained from the leaves of two Coca species native to South Am ...

, from coca plant (''

Erythroxylum coca ''Erythroxylum coca'' is one of two species of cultivated coca. Description The coca plant resembles a blackthorn bush, and grows to a height of . The branches are straight, and the leaves, which have a green tint, are thin, opaque, oval, and tap ...

'') * Ecgonine, a precursor and metabolite of cocaine *

Benzoylecgonine Benzoylecgonine is the main metabolite of cocaine, formed by the liver and excreted in the urine. It is the compound tested for in most cocaine urine drug screens. Pharmacokinetics Chemically, benzoylecgonine is the benzoate ester of ecgonine. I ...

, a metabolite of cocaine * Hydroxytropacocaine, from coca plant (''Erythroxylum coca'') * Methylecgonine cinnamate, from coca plant (''Erythroxylum coca'')

Others

Catuabine Catuabines are a group of tropane alkaloids, isolated from ''Erythroxylum vaccinifolium'', which are used in the preparation of the drug Catuaba (which in traditional Brazilian medicine is purported to be an aphrodisiac and central nervous system s ...

s, found in

catuaba The name Catuaba ( , via Portuguese from Guarani) is used for the infusions of the bark of a number of trees native to Brazil. The most widely used barks are derived from the trees '' Trichilia catigua'' and '' Erythroxylum vaccinifolium''. Othe ...

, an infusion or dry extract made from '' Erythroxylum vaccinifolium'' *

Scopine Scopine is a tropane alkaloid found in a variety of plants including '' Mandragora'' root, '' Senecio mikanioides'' (''Delairea odorata''), ''Scopolia carniolica'', and '' Scopolia lurida''. Scopine can be prepared by the hydrolysis of scopola ...

Synthetic analogs of tropane alkaloids also exist, such as the

phenyltropane Phenyltropanes (PTs) were originally developed to reduce cocaine addiction and dependency. In general these compounds act as inhibitors of the plasmalemmal monoamine reuptake transporters. Although RTI holds a strong position in this field, ...

s. They are not considered to be alkaloids per definition.

Biosynthesis

The biosynthesis of the tropane alkaloids have attracted intense interest because of their high physiological activity as well as the presence of the bicyclic

core.

References

{{Reflist Deliriants