Beta-carboline
Encyclopedia
β-Carboline is an organic
amine
that is the prototype of a class of compounds
known as β-carbolines.
s are widespread in plants and animal
s, and frequently act as monoamine oxidase inhibitor
s (MAOI). As components of the liana Banisteriopsis caapi
, the β-carbolines harmine
, harmaline
, and tetrahydroharmine play a pivotal role in the pharmacology of the indigenous hallucinogenic drug ayahuasca
by preventing the breakdown of dimethyltryptamine
in the gut by inhibiting monoamine oxidase
, thus making it psychoactive upon oral administration. Some β-carbolines, notably tryptoline
and pinoline
, are formed naturally in the human body. The latter is implicated along with melatonin
in the role of the pineal gland
in regulating the sleep-wake cycle. The β-carboline can link to cerebral benzodiazepine
receptors and induce inverse agonist effect.
United States Patent
Number 5591738 describes a method for treating various chemical dependencies via the administration of beta-carbolines.
. They consist of an indole skeleton and various side chains. The structure of β-carboline is similar to that of tryptamine
, with the ethylamine
chain re-connected to the indole
ring via an extra carbon
atom, to produce a three-ringed structure. Indeed, biosynthesis of β-carbolines is believed to follow this route from analogous tryptamines. Different levels of saturation
are possible in the third ring, which is indicated here in the structural formula
by colouring the optionally double bonds red and blue:
As a result of the presence of β-carbolines in the cuticle of scorpions, their skin is known to fluoresce when exposed to certain wavelengths of ultraviolet
light such as that produced by a blacklight
.
Several β-carbolines have actions opposite to those of benzodiazepine
s: convulsive, anxiogenic and memory enhancing.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
that is the prototype of a class of compounds
Chemical compound
A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together...
known as β-carbolines.
Pharmacology
β-Carboline alkaloidAlkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
s are widespread in plants and animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s, and frequently act as monoamine oxidase inhibitor
Monoamine oxidase inhibitor
Monoamine oxidase inhibitors are a class of antidepressant drugs prescribed for the treatment of depression. They are particularly effective in treating atypical depression....
s (MAOI). As components of the liana Banisteriopsis caapi
Banisteriopsis caapi
Banisteriopsis caapi, also known as Ayahuasca, Caapi or Yage, is a South American jungle vine of the family Malpighiaceae. It is used to prepare Ayahuasca, a decoction that has a long history of entheogenic uses as a medicine and "plant teacher" among the indigenous peoples of the Amazon Rainforest...
, the β-carbolines harmine
Harmine
Harmine is a fluorescent harmala alkaloid belonging to the beta-carboline family of compounds. It occurs in a number of different plants, most notably the Middle Eastern plant harmal or Syrian rue and the South American vine Banisteriopsis caapi...
, harmaline
Harmaline
Harmaline is a fluorescent psychoactive indole alkaloid from the group of harmala alkaloids and beta-carbolines. It is the reduced hydrogenated form of harmine.-Occurrence in nature:...
, and tetrahydroharmine play a pivotal role in the pharmacology of the indigenous hallucinogenic drug ayahuasca
Ayahuasca
Ayahuasca is any of various psychoactive infusions or decoctions prepared from the Banisteriopsis spp. vine, usually mixed with the leaves of dimethyltryptamine-containing species of shrubs from the Psychotria genus...
by preventing the breakdown of dimethyltryptamine
Dimethyltryptamine
N,N-Dimethyltryptamine is a naturally occurring psychedelic compound of the tryptamine family. DMT is found in several plants, and also in trace amounts in humans and other mammals, where it is originally derived from the essential amino acid tryptophan, and ultimately produced by the enzyme INMT...
in the gut by inhibiting monoamine oxidase
Monoamine oxidase
L-Monoamine oxidases are a family of enzymes that catalyze the oxidation of monoamines. They are found bound to the outer membrane of mitochondria in most cell types in the body. The enzyme was originally discovered by Mary Bernheim in the liver and was named tyramine oxidase...
, thus making it psychoactive upon oral administration. Some β-carbolines, notably tryptoline
Tryptoline
Tryptoline, also known as tetrahydro-β-carboline and tetrahydronorharmane, is a natural organic derivative of beta-carboline. It is an alkaloid chemically related to tryptamines...
and pinoline
Pinoline
Pinoline is a methoxylated tryptoline that occurs in the pineal gland during the metabolism of melatonin. Its chemical names are 5-methoxytryptoline and 6-methoxy-1,2,3,4-tetrahydro-β-carboline . The biological activity of this molecule is of interest as a potential free radical scavenger ,...
, are formed naturally in the human body. The latter is implicated along with melatonin
Melatonin
Melatonin , also known chemically as N-acetyl-5-methoxytryptamine, is a naturally occurring compound found in animals, plants, and microbes...
in the role of the pineal gland
Pineal gland
The pineal gland is a small endocrine gland in the vertebrate brain. It produces the serotonin derivative melatonin, a hormone that affects the modulation of wake/sleep patterns and seasonal functions...
in regulating the sleep-wake cycle. The β-carboline can link to cerebral benzodiazepine
Benzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...
receptors and induce inverse agonist effect.
United States Patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
Number 5591738 describes a method for treating various chemical dependencies via the administration of beta-carbolines.
Structure
β-Carbolines belong to the group of Indole alkaloidsIndole alkaloids
Indole alkaloids are a class of alkaloids containing a structural moiety of indole; many indole alkaloids also include isoprene groups. Containing more than 4100 known different compounds, it is one of the largest classes of alkaloids. Many of them possess significant physiological activity and...
. They consist of an indole skeleton and various side chains. The structure of β-carboline is similar to that of tryptamine
Tryptamine
Tryptamine is a monoamine alkaloid found in plants, fungi, and animals. It is based around the indole ring structure, and is chemically related to the amino acid tryptophan, from which its name is derived...
, with the ethylamine
Ethylamine
Ethylamine is an organic compound with the formula CH3CH2NH2. This colourless gas has a strong ammonia-like odor. It is miscible with virtually all solvents and is considered to be a weak base, as is typical for amines. Ethylamine is widely used in chemical industry and organic...
chain re-connected to the indole
Indole
Indole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. Indole is a popular component of fragrances and the precursor to many pharmaceuticals. Compounds that contain an...
ring via an extra carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
atom, to produce a three-ringed structure. Indeed, biosynthesis of β-carbolines is believed to follow this route from analogous tryptamines. Different levels of saturation
Saturation (chemistry)
In chemistry, saturation has six different meanings, all based on reaching a maximum capacity...
are possible in the third ring, which is indicated here in the structural formula
Structural formula
The structural formula of a chemical compound is a graphical representation of the molecular structure, showing how the atoms are arranged. The chemical bonding within the molecule is also shown, either explicitly or implicitly...
by colouring the optionally double bonds red and blue:
Examples of β-carbolines
Some of the more important β-carbolines are tabulated by structure below.| Short Name | R1 | R6 | R7 | Structure | ||
|---|---|---|---|---|---|---|
| β-Carboline |  |
|||||
| Tryptoline Tryptoline Tryptoline, also known as tetrahydro-β-carboline and tetrahydronorharmane, is a natural organic derivative of beta-carboline. It is an alkaloid chemically related to tryptamines... |
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|||||
| Pinoline Pinoline Pinoline is a methoxylated tryptoline that occurs in the pineal gland during the metabolism of melatonin. Its chemical names are 5-methoxytryptoline and 6-methoxy-1,2,3,4-tetrahydro-β-carboline . The biological activity of this molecule is of interest as a potential free radical scavenger ,... |
Methoxy In chemistry , methoxy refers to the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula O–CH3.The word is used in organic nomenclature usually to describe an ether... |
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||||
| Harmane | |
|
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|||
| Harmine Harmine Harmine is a fluorescent harmala alkaloid belonging to the beta-carboline family of compounds. It occurs in a number of different plants, most notably the Middle Eastern plant harmal or Syrian rue and the South American vine Banisteriopsis caapi... |
|
|
|
Methoxy In chemistry , methoxy refers to the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula O–CH3.The word is used in organic nomenclature usually to describe an ether... |
.svg.png) |
|
| Harmaline Harmaline Harmaline is a fluorescent psychoactive indole alkaloid from the group of harmala alkaloids and beta-carbolines. It is the reduced hydrogenated form of harmine.-Occurrence in nature:... |
|
|
Methoxy In chemistry , methoxy refers to the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula O–CH3.The word is used in organic nomenclature usually to describe an ether... |
.svg.png) |
||
| Tetrahydroharmine | |
Methoxy In chemistry , methoxy refers to the functional group consisting of a methyl group bound to oxygen. This alkoxy group has the formula O–CH3.The word is used in organic nomenclature usually to describe an ether... |
.svg.png) |
Occurrence in nature
"There are presently 64 known β-carboline alkaloids dispersed throughout at least eight plant families." The seeds of Peganum harmala (Syrian Rue) are a good source of beta-carbolines, since they contain about 2-6% alkaloids, most of which is harmaline.As a result of the presence of β-carbolines in the cuticle of scorpions, their skin is known to fluoresce when exposed to certain wavelengths of ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
light such as that produced by a blacklight
Black light
A black light, also referred to as a UV light, ultraviolet light, or Wood's lamp, is a lamp that emits ultraviolet radiation in the long-wave range, and little visible light...
.
Several β-carbolines have actions opposite to those of benzodiazepine
Benzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...
s: convulsive, anxiogenic and memory enhancing.
External links
- TiHKAL #44
- TiHKAL in general
- Beta-carbolines in Coffee