Tetrahydroharmine (THH) is a
fluorescent
Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with color ...
indole alkaloid
Indole alkaloids are a class of alkaloids containing a structural moiety of indole; many indole alkaloids also include isoprene groups and are thus called terpene indole or secologanin tryptamine alkaloids. Containing more than 4100 known differ ...
and
β-carboline that occurs in the tropical
liana
A liana is a long-Plant stem, stemmed Woody plant, woody vine that is rooted in the soil at ground level and uses trees, as well as other means of vertical support, to climb up to the Canopy (biology), canopy in search of direct sunlight. T ...
species ''
Banisteriopsis caapi
''Banisteriopsis caapi'', also known as, caapi, soul vine, yagé (yage), or ayahuasca (the latter of which also refers to the psychedelic decoction made with the vine and a plant source of dimethyltryptamine) is a South American liana of the fam ...
''.
Effects
THH has been reported to produce
psychoactive
A psychoactive drug, psychopharmaceutical, mind-altering drug, consciousness-altering drug, psychoactive substance, or psychotropic substance is a chemical substance that alters psychological functioning by modulating central nervous system acti ...
effects similar to those of
harmaline in humans.
It has been reported to be about one-third as
potent as harmaline at a dose of 300mg
orally.
THH is believed to be one of the constituents of ''
Banisteriopsis caapi
''Banisteriopsis caapi'', also known as, caapi, soul vine, yagé (yage), or ayahuasca (the latter of which also refers to the psychedelic decoction made with the vine and a plant source of dimethyltryptamine) is a South American liana of the fam ...
'' responsible for the
hallucinogen
Hallucinogens, also known as psychedelics, entheogens, or historically as psychotomimetics, are a large and diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, mo ...
ic effects of the plant.
Pharmacology
THH, like other
harmala alkaloid
Harmala alkaloids are several alkaloids that act as monoamine oxidase inhibitors (MAOIs). These alkaloids are found in the seeds of ''Peganum harmala'' (also known as harmal or Syrian rue), as well as ''Banisteriopsis caapi'' (ayahuasca), leave ...
s in
''B. caapi'', namely
harmaline and
harmine, is a
reversible inhibitor of monoamine oxidase A (RIMA),
but it also inhibits the
reuptake
Reuptake is the reabsorption of a neurotransmitter by a neurotransmitter transporter located along the plasma membrane of an axon terminal (i.e., the pre-synaptic neuron at a synapse) or glial cell after it has performed its function of transmi ...
of
serotonin
Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, ...
.
THH contributes to ''B. caapi''
's
psychoactivity as a
serotonin reuptake inhibitor
A serotonin reuptake inhibitor (SRI) is a type of drug which acts as a reuptake inhibitor of the neurotransmitter serotonin (5-hydroxytryptamine, or 5-HT) by blocking the drug action, action of the serotonin transporter (SERT). This in turn lea ...
.
In contrast to other
β-carbolines, THH shows minimal
affinity
Affinity may refer to:
Commerce, finance and law
* Affinity (law), kinship by marriage
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* Affinity Credit Union, a Saskatchewan-based credit union
* Affinity Equity Pa ...
for the serotonin
5-HT2A receptor (K
i = >10,000nM for
racemic
In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) 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 r ...
THH and ''R''(+)-THH, K
i = 5,890nM for ''S''(–)-THH).
Similarly, THH shows negligible affinity for the serotonin
5-HT1A and
5-HT2C receptors and the
dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...
D2 receptor.
Society and culture
Legal status
Australia
Harmala alkaloids are considered Schedule 9 prohibited substances under the
Poisons Standard (October 2015).
A Schedule 9 substance is a substance which may be abused or misused, the manufacture, possession, sale or use of which should be prohibited by law except when required for medical or scientific research, or for analytical, teaching or training purposes with approval of Commonwealth and/or State or Territory Health Authorities.
See also
*
Substituted β-carboline
A substituted β-carboline is a chemical compound featuring a β-carboline moiety (chemistry), moiety with one or more chemical substituent, substitutions. β-Carbolines include more than one hundred alkaloids and synthetic compounds. The effect ...
*
Ayahuasca
AyahuascaPronounced as in the UK and in the US. Also occasionally known in English as ''ayaguasca'' (Spanish-derived), ''aioasca'' (Brazilian Portuguese-derived), or as ''yagé'', pronounced or . Etymologically, all forms but ''yagé'' descen ...
*
Coronaridine
Coronaridine, also known as 18-carbomethoxyibogamine, is an alkaloid found in '' Tabernanthe iboga'' and related species, including '' Tabernaemontana divaricata'' for which (under the now obsolete synonym ''Ervatamia coronaria'') it was named.
...
References
Further reading
*
{{Tryptamines
Beta-Carbolines
N-Monoalkyltryptamines
Psychedelic tryptamines
Serotonin receptor modulators
Serotonin reuptake inhibitors
Tryptamine alkaloids