''tert''-Amyl alcohol (TAA) or 2-methylbutan-2-ol (2M2B), is a branched

pentanol Amyl alcohols are alcohols with the formula C5H11OH. Eight are known. A mixture of amyl alcohols (also called amyl alcohol) can be obtained from fusel alcohol. Amyl alcohol is used as a solvent and in esterification In chemistry, an ester is ...

. Historically, TAA has been used as an

anesthetic An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia ⁠— ⁠in other words, to result in a temporary loss of sensation or awareness. They may be divided into t ...

and more recently as a

recreational drug Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an Sub ...

. TAA is mostly a positive allosteric modulator for GABA_A receptors in the same way as

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

. The psychotropic effects of TAA and ethanol are similar, though distinct. Impact on coordination and balance are proportionately more prominent with TAA, which is significantly more potent by weight than ethanol. Its appeal as an alternative to ethanol may stem from its lack of a hangover (due to different

metabolic pathways In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell. The reactants, products, and intermediates of an enzymatic reaction are known as metabolites, which are modified by a sequence of chemical ...

) and the fact that it is often not detected on standard drug test. TAA is a colorless liquid with a burning flavor and an unpleasant odor similar to

paraldehyde Paraldehyde is the cyclic trimer (chemistry), trimer of acetaldehyde molecules. Formally, it is a derivative of 1,3,5-trioxane, with a methyl group substituted for a hydrogen atom at each carbon. The corresponding tetramer is metaldehyde. A colo ...

with a hint of

camphor Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel (''Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the kapu ...

. TAA remains liquid at room temperature, making it a useful alternative solvent to ''tert''-butyl alcohol.

Production

TAA is primarily made by the hydration of 2-methyl-2-butene in the presence of an acidic

catalyst Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

Natural occurrence

Fusel alcohol Fusel alcohols or fuselol, also sometimes called fusel oils in Europe, are mixtures of several higher alcohols (those with more than two carbons, chiefly amyl alcohol) produced as a by-product of alcoholic fermentation. The word ''Fusel'' is G ...

s like TAA are grain fermentation byproducts, and therefore trace amounts of TAA are present in many alcoholic beverages. Traces of TAA have been detected in other foods, like fried

bacon Bacon is a type of Curing (food preservation), salt-cured pork made from various cuts of meat, cuts, typically the pork belly, belly or less fatty parts of the back. It is eaten as a side dish (particularly in breakfasts), used as a central in ...

cassava ''Manihot esculenta'', common name, commonly called cassava, manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America, from Brazil, Paraguay and parts of the Andes. Although ...

and rooibos tea. TAA is also present in

rabbit Rabbits are small mammals in the family Leporidae (which also includes the hares), which is in the order Lagomorpha (which also includes pikas). They are familiar throughout the world as a small herbivore, a prey animal, a domesticated ...

milk Milk is a white liquid food produced by the mammary glands of lactating mammals. It is the primary source of nutrition for young mammals (including breastfeeding, breastfed human infants) before they are able to digestion, digest solid food. ...

and seems to play a role in

pheromone A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavio ...

-inducing suckling in the newborn rabbit.

History

From about the 1880s to the 1950s, TAA was used as an

with the contemporary name of ''amylene hydrate'', but it was rarely used because more efficient drugs existed. In the 1930s, TAA was mainly used as a solvent for the primary anesthetic tribromoethanol (TBE). Like

chloroform Chloroform, or trichloromethane (often abbreviated as TCM), is an organochloride with the formula and a common solvent. It is a volatile, colorless, sweet-smelling, dense liquid produced on a large scale as a precursor to refrigerants and po ...

, TBE is toxic for the liver, so the use of such solutions declined in the 1940s in humans. TBE-TAA-solutions remained in use as short-acting anesthetics for

laboratory mice The laboratory mouse or lab mouse is a small mammal of the order Rodentia which is bred and used for scientific research or feeders for certain pets. Laboratory animal sources for these mice are usually of the species ''Mus musculus''. They a ...

and

rats Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' (pack rats), '' Bandicota'' (bandicoot ...

. Such solutions are sometimes called ''Avertin'', which was a brand name for the now discontinued TAA and TBE solution with a volume ratio of 0.5:1 made by Winthrop Laboratories. TAA has emerged recently as a

Use and effects

Ingestion or inhalation of TAA causes

euphoria Euphoria ( ) is the experience (or affect) of pleasure or excitement and intense feelings of well-being and happiness. Certain natural rewards and social activities, such as aerobic exercise, laughter, listening to or making music and da ...

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or Psychomotor agitation, excitement. They are central nervous system (CNS) Depressant, depressants and interact with brain activity, causing its decelera ...

hypnotic A hypnotic (from Ancient Greek, Greek ''Hypnos'', sleep), also known as a somnifacient or soporific, and commonly known as sleeping pills, are a class of psychoactive drugs whose primary function is to sleep induction, induce sleep and to trea ...

, and

anticonvulsant Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatme ...

effects similar to

. When ingested, the effects of TAA may begin in about 30 minutes and can last up to 1–2 days. 2–4 grams of TAA is sufficient to produce a hypnotic effect. About 100 g of ethanol induces a similar level of sedation.

Overdose and toxicity

The smallest known dose of TAA that has killed a person is 30 mL. An overdose produces symptoms similar to

alcohol poisoning Alcohol intoxication, commonly described in higher doses as drunkenness or inebriation, and known in overdose as alcohol poisoning, is the behavior and physical effects caused by recent consumption of alcohol. The technical term ''intoxication ...

and is a medical emergency due to the sedative/depressant properties which manifest in overdose as potentially lethal

respiratory depression Hypoventilation (also known as respiratory depression) occurs when ventilation is inadequate (''hypo'' meaning "below") to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapni ...

. Sudden loss of consciousness, simultaneous

respiratory The respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies gr ...

and

metabolic acidosis Metabolic acidosis is a serious electrolyte disorder characterized by an imbalance in the body's acid-base balance. Metabolic acidosis has three main root causes: increased acid production, loss of bicarbonate, and a reduced ability of the kidn ...

fast heartbeat Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal ( ...

, increased blood pressure, pupil constriction,

coma A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to Nociception, respond normally to Pain, painful stimuli, light, or sound, lacks a normal Circadian rhythm, sleep-wake cycle and does not initiate ...

, respiratory depression and death may follow from an overdose. The oral in rats is 1 g/kg. The subcutaneous LD₅₀ in mice is 2.1 g/kg.

Metabolism

In rats, TAA is primarily

metabolized Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...

via

glucuronidation Glucuronidation is often involved in drug metabolism of substances such as drugs, pollutants, bilirubin, androgens, estrogens, mineralocorticoids, glucocorticoids, fatty acid derivatives, retinoids, and bile acids. These linkages involve gly ...

, as well as by oxidation to 2-methyl-2,3-butanediol. It is likely that the same path is followed in humans, though older sources suggest TAA is excreted unchanged. 2-Methyl-2-butanol oxidation

The use of TAA cannot be detected with general ethanol tests or other ordinary drug tests. Its use can be detected from a blood or a urine sample by using

gas chromatography–mass spectrometry Gas chromatography–mass spectrometry (GC–MS) is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC–MS include drug detectio ...

for up to 48 hours after consumption.

References

{{DEFAULTSORT:Amyl alcohol, tert- Alcohol solvents Tertiary alcohols Sedatives Designer drugs GABAA receptor positive allosteric modulators Alkanols