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Lewis structure of acetaldehyde Acetaldehyde-2D-flat.svg
Lewis structure of acetaldehyde
Skeletal structure of acetaldehyde Acetaldehyde-tall-2D-skeletal.png
Skeletal structure of acetaldehyde
Ball-and-stick model Acetaldehyde-3D-balls.png
Ball-and-stick model
Space-filling model Acetaldehyde-3D-vdW.png
Space-filling model
Preferred IUPAC name
Acetaldehyde [1]
Systematic IUPAC name
Ethanal [1]
Other names
Acetic aldehyde
Ethyl aldehyde [2]
Acetylaldehyde [3]
3D model (JSmol)
ECHA InfoCard 100.000.761 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 200-836-8
PubChem CID
RTECS number
  • AB1925000
  • InChI=1S/C2H4O/c1-2-3/h2H,1H3 Yes check.svgY
  • InChI=1/C2H4O/c1-2-3/h2H,1H3
  • O=CC
  • CC=O
Molar mass 44.053 g·mol−1
AppearanceColourless gas or liquid
Odor Ethereal
Density 0.784 g·cm−3 (20 °C) [4]

0.7904–0.7928 g·cm−3 (10 °C) [4]

Melting point −123.37 °C (−190.07 °F; 149.78 K)
Boiling point 20.2 °C (68.4 °F; 293.3 K)
Solubility miscible with ethanol, ether, benzene, toluene, xylene, turpentine, acetone
slightly soluble in chloroform
log P -0.34
Vapor pressure 740 mmHg (20 °C) [5]
Acidity (pKa)13.57 (25 °C, H2O) [6]
-.5153−6 cm3/g
Viscosity 0.21 mPa-s at 20 °C (0.253 mPa-s at 9.5 °C) [7]
trigonal planar (sp2) at C1
tetrahedral (sp3) at C2
2.7 D
Thermochemistry [8]
89 J·mol−1·K−1
Std molar
160.2 J·mol−1·K−1
−192.2 kJ·mol−1
-127.6 kJ·mol−1
Related compounds
Related aldehydes
Related compounds
Ethylene oxide
Occupational safety and health (OHS/OSH):
Main hazards
potential occupational carcinogen [9]
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg [10]
H224, H319, H335, H351 [10]
P210, P261, P281, P305+P351+P338 [10]
NFPA 704 (fire diamond)
NFPA 704.svgHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 3: Capable of detonation or explosive decomposition but requires a strong initiating source, must be heated under confinement before initiation, reacts explosively with water, or will detonate if severely shocked. E.g. hydrogen peroxideSpecial hazards (white): no code
Flash point −39.00 °C; −38.20 °F; 234.15 K
175.00 °C; 347.00 °F; 448.15 K [5]
Explosive limits 4.0–60%
Lethal dose or concentration (LD, LC):
1930 mg/kg (rat, oral)
13,000 ppm (rat),
17,000 ppm (hamster),
20,000 ppm (rat) [9]
NIOSH (US health exposure limits):
PEL (Permissible)
200 ppm (360 mg/m3) [5]
IDLH (Immediate danger)
2000 ppm [5] [9]
Safety data sheet (SDS) HMDB
Supplementary data page
Acetaldehyde (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

Acetaldehyde (IUPAC systematic name ethanal) is an organic chemical compound with the formula CH3 CHO, sometimes abbreviated as MeCHO. It is a colorless liquid or gas, boiling near room temperature. It is one of the most important aldehydes, occurring widely in nature and being produced on a large scale in industry. Acetaldehyde occurs naturally in coffee, bread, and ripe fruit, [11] and is produced by plants. It is also produced by the partial oxidation of ethanol by the liver enzyme alcohol dehydrogenase and is a contributing cause of hangover after alcohol consumption. Pathways of exposure include air, water, land, or groundwater, as well as drink and smoke. [12] Consumption of disulfiram inhibits acetaldehyde dehydrogenase, the enzyme responsible for the metabolism of acetaldehyde, thereby causing it to build up in the body.

The International Agency for Research on Cancer (IARC) has listed acetaldehyde as a Group 1 carcinogen. [13] Acetaldehyde is "one of the most frequently found air toxins with cancer risk greater than one in a million". [14]


Acetaldehyde was first observed by the Swedish pharmacist/chemist Carl Wilhelm Scheele (1774); [15] it was then investigated by the French chemists Antoine François, comte de Fourcroy and Louis Nicolas Vauquelin (1800), [16] and the German chemists Johann Wolfgang Döbereiner (1821, 1822, 1832) [17] and Justus von Liebig (1835). [18] [19] In 1835, Liebig named it "aldehyde"; [20] the name was later altered to "acetaldehyde". [21]


In 2003, global production was about 1 million tonnes.[ citation needed ] Before 1962, ethanol and acetylene were the major sources of acetaldehyde. Since then, ethylene is the dominant feedstock. [22]

The main method of production is the oxidation of ethene by the Wacker process, which involves oxidation of ethene using a homogeneous palladium/copper catalyst system:

In the 1970s, the world capacity of the Wacker-Hoechst direct oxidation process exceeded 2 million tonnes annually.

Smaller quantities can be prepared by the partial oxidation of ethanol in an exothermic reaction. This process typically is conducted over a silver catalyst at about 500–650 °C. [22]

This method is one of the oldest routes for the industrial preparation of acetaldehyde.

Other methods

Hydration of acetylene

Prior to the Wacker process and the availability of cheap ethylene, acetaldehyde was produced by the hydration of acetylene. [23] This reaction is catalyzed by mercury(II) salts:

The mechanism involves the intermediacy of vinyl alcohol, which tautomerizes to acetaldehyde. The reaction is conducted at 90–95 °C, and the acetaldehyde formed is separated from water and mercury and cooled to 25–30 °C. In the wet oxidation process, iron(III) sulfate is used to reoxidize the mercury back to the mercury(II) salt. The resulting iron(II) sulfate is oxidized in a separate reactor with nitric acid. [22]

The enzyme Acetylene hydratase discovered in the strictly anaerobic bacterium Pelobacter acetylenicus can catalyze an analogous reaction without involving any compounds of mercury. [24] However, it has thus far not been brought to any large-scale or commercial use.

Dehydrogenation of ethanol

Traditionally, acetaldehyde was produced by the partial dehydrogenation of ethanol:

In this endothermic process, ethanol vapor is passed at 260–290 °C over a copper-based catalyst. The process was once attractive because of the value of the hydrogen coproduct, [22] but in modern times is not economically viable.

Hydroformylation of methanol

The hydroformylation of methanol with catalysts like cobalt, nickel, or iron salts also produces acetaldehyde, although this process is of no industrial importance. Similarly noncompetitive, acetaldehyde arises from synthesis gas with modest selectivity. [22]


Tautomerization of acetaldehyde to vinyl alcohol

Tautomeric equilibrium between acetaldehyde and vinyl alcohol. Ethanal Ethenol Tautomerie.svg
Tautomeric equilibrium between acetaldehyde and vinyl alcohol.

Like many other carbonyl compounds, acetaldehyde tautomerizes to give an enol (vinyl alcohol; IUPAC name: ethenol):

CH3CH=O ⇌ CH2=CHOH         H298,g = +42.7 kJ/mol

The equilibrium constant is 6×10−7 at room temperature, thus that the relative amount of the enol form in a sample of acetaldehyde is very small. [25] At room temperature, acetaldehyde (CH3CH=O) is more stable than vinyl alcohol (CH2=CHOH) by 42.7 kJ/mol: [26] Overall the keto-enol tautomerization occurs slowly but is catalyzed by acids.

Photo-induced keto-enol tautomerization is viable under atmospheric or stratospheric conditions. This photo-tautomerization is relevant to the Earth's atmosphere, because vinyl alcohol is thought to be a precursor to carboxylic acids in the atmosphere. [27] [28]

Addition and condensation reactions

Acetaldehyde is a common electrophile in organic synthesis. [29] In addition reactions acetaldehyde is prochiral. It is used primarily as a source of the "CH3C+H(OH)" synthon in aldol reactions and related condensation reactions. [30] Grignard reagents and organolithium compounds react with MeCHO to give hydroxyethyl derivatives. [31] In one of the more spectacular addition reactions, formaldehyde in the presence of calcium hydroxide adds to MeCHO to give pentaerythritol, C(CH2OH)4 and formate. [32]

In a Strecker reaction, acetaldehyde condenses with cyanide and ammonia to give, after hydrolysis, the amino acid alanine. [33] Acetaldehyde can condense with amines to yield imines; for example, with cyclohexylamine to give N-ethylidenecyclohexylamine. These imines can be used to direct subsequent reactions like an aldol condensation. [34]

It is also a building block in the synthesis of heterocyclic compounds. In one example, it converts, upon treatment with ammonia, to 5-ethyl-2-methylpyridine ("aldehyde-collidine"). [35]

Polymeric forms

Paraldehyde structure.svg
Cyclic oligomers of acetaldehyde (CH3CHO)n: paraldehyde (n = 3, left) and metaldehyde (n = 4, right)

Three molecules of acetaldehyde condense to form "paraldehyde", a cyclic trimer containing C-O single bonds. Similarly condensation of four molecules of acetaldehyde give the cyclic molecule metaldehyde. Paraldehyde can be produced in good yields, using a sulfuric acid catalyst. Metaldehyde is only obtained in a few percent yield and with cooling, often using HBr rather than H2SO4 as the catalyst. At −40 °C in the presence of acid catalysts, polyacetaldehyde is produced. [22] There are two stereomers of paraldehyde and four of metaldehyde.

The German chemist Valentin Hermann Weidenbusch (1821–1893) synthesized paraldehyde in 1848 by treating acetaldehyde with acid (either sulfuric or nitric acid) and cooling to 0°C. He found it quite remarkable that when paraldehyde was heated with a trace of the same acid, the reaction went the other way, recreating acetaldehyde. [36]

Acetal derivatives

Conversion of acetaldehyde to 1,1-diethoxyethane, R = CH3, R = CH3CH2 Acetal formation 2.png
Conversion of acetaldehyde to 1,1-diethoxyethane, R = CH3, R = CH3CH2

Acetaldehyde forms a stable acetal upon reaction with ethanol under conditions that favor dehydration. The product, CH3CH(OCH2CH3)2, is formally named 1,1-diethoxyethane but is commonly referred to as "acetal". [37] This can cause confusion as "acetal" is more commonly used to describe compounds with the functional groups RCH(OR')2 or RR'C(OR'')2 rather than referring to this specific compound – in fact, 1,1-diethoxyethane is also described as the diethyl acetal of acetaldehyde.

Precursor to vinylphosphonic acid

Acetaldehyde is a precursor to vinylphosphonic acid, which is used to make adhesives and ion conductive membranes. The synthesis sequence begins with a reaction with phosphorus trichloride: [38]

PCl3 + CH3CHO → CH3CH(O)PCl3+
CH3CH(O)PCl3+ + 2 CH3CO2H → CH3CH(Cl)PO(OH)2 + 2 CH3COCl
CH3CH(Cl)PO(OH)2 → CH2=CHPO(OH)2 + HCl


In the liver, the enzyme alcohol dehydrogenase oxidizes ethanol into acetaldehyde, which is then further oxidized into harmless acetic acid by acetaldehyde dehydrogenase. These two oxidation reactions are coupled with the reduction of NAD+ to NADH. [39] In the brain, the enzyme catalase is primarily responsible for oxidizing ethanol to acetaldehyde, and alcohol dehydrogenase plays a minor role. [39] The last steps of alcoholic fermentation in bacteria, plants, and yeast involve the conversion of pyruvate into acetaldehyde and carbon dioxide by the enzyme pyruvate decarboxylase, followed by the conversion of acetaldehyde into ethanol. The latter reaction is again catalyzed by an alcohol dehydrogenase, now operating in the opposite direction.

Many East Asian people have an ALDH2 mutation which makes them significantly less efficient at oxidizing acetaldehyde. On consuming alcohol, their bodies tend to accumulate excessive amounts of acetaldehyde, causing the so-called alcohol flush reaction. [40] They develop a characteristic flush on the face and body, along with "nausea, headache and general physical discomfort". [41] Ingestion of the drug disulfiram, which inhibits ALDH2, leads to a similar reaction. See section #Aggravating factors below. [42]


Traditionally, acetaldehyde was mainly used as a precursor to acetic acid. This application has declined because acetic acid is produced more efficiently from methanol by the Monsanto and Cativa processes. Acetaldehyde is an important precursor to pyridine derivatives, pentaerythritol, and crotonaldehyde. Urea and acetaldehyde combine to give a useful resin. Acetic anhydride reacts with acetaldehyde to give ethylidene diacetate, a precursor to vinyl acetate, which is used to produce polyvinyl acetate. [22]

The global market for acetaldehyde is declining. Demand has been impacted by changes in the production of plasticizer alcohols, which has shifted because n-butyraldehyde is less often produced from acetaldehyde, instead being generated by hydroformylation of propylene. Likewise, acetic acid, once produced from acetaldehyde, is made predominantly by the lower-cost methanol carbonylation process. [43] The impact on demand has led to increase in prices and thus slowdown in the market.

Production of Acetaldehyde Production of acetaldehyde.JPG
Production of Acetaldehyde
Consumption of acetaldehyde (103 t) in 2003 [22]
(* Included in others -glyoxal/glyoxalic acid, crotonaldehyde, lactic acid, n-butanol, 2-ethylhexanol)
ProductUSAMexicoW. EuropeJapanTotal
Acetic Acid/Acetic anhydride-118947147
Acetate esters35854224321
Pyridine and pyridine bases7310*83
Peracetic acid23*23
1,3-Butylene glycol14*14

China is the largest consumer of acetaldehyde in the world, accounting for almost half of global consumption in 2012. Major use has been the production of acetic acid. Other uses such as pyridines and pentaerythritol are expected to grow faster than acetic acid, but the volumes are not large enough to offset the decline in acetic acid. As a consequence, overall acetaldehyde consumption in China may grow slightly at 1.6% per year through 2018. Western Europe is the second-largest consumer of acetaldehyde worldwide, accounting for 20% of world consumption in 2012. As with China, the Western European acetaldehyde market is expected to increase only very slightly at 1% per year during 2012–2018. However, Japan could emerge as a potential consumer for acetaldehyde in next five years due to newfound use in commercial production of butadiene. The supply of butadiene has been volatile in Japan and the rest of Asia. This should provide the much needed boost to the flat market, as of 2013. [44]


Exposure limits

The threshold limit value is 25ppm (STEL/ceiling value) and the MAK (Maximum Workplace Concentration) is 50 ppm. At 50 ppm acetaldehyde, no irritation or local tissue damage in the nasal mucosa is observed. When taken up by the organism, acetaldehyde is metabolized rapidly in the liver to acetic acid. Only a small proportion is exhaled unchanged. After intravenous injection, the half-life in the blood is approximately 90 seconds. [22]



Many serious cases of acute intoxication have been recorded. [22] Acetaldehyde naturally breaks down in the human body. [12] [45]


Acetaldehyde is an irritant of the skin, eyes, mucous membranes, throat, and respiratory tract. This occurs at concentrations as low as 1000 ppm. Symptoms of exposure to this compound include nausea, vomiting, and headache. These symptoms may not happen immediately. The perception threshold for acetaldehyde in air is in the range between 0.07 and 0.25 ppm. [22] At such concentrations, the fruity odor of acetaldehyde is apparent. Conjunctival irritations have been observed after a 15-minute exposure to concentrations of 25 and 50 ppm, but transient conjunctivitis and irritation of the respiratory tract have been reported after exposure to 200 ppm acetaldehyde for 15 minutes.


Acetaldehyde is carcinogenic in humans. [46] [47] In 1988 the International Agency for Research on Cancer stated, "There is sufficient evidence for the carcinogenicity of acetaldehyde (the major metabolite of ethanol) in experimental animals." [48] In October 2009 the International Agency for Research on Cancer updated the classification of acetaldehyde stating that acetaldehyde included in and generated endogenously from alcoholic beverages is a Group I human carcinogen. [49] In addition, acetaldehyde is damaging to DNA [50] and causes abnormal muscle development as it binds to proteins. [51]

Acetaldehyde induces DNA interstrand crosslinks, a form of DNA damage. These can be repaired by either of two replication-coupled DNA repair pathways. [52] The first is referred to as the FA pathway, because it employs gene products defective in Fanconi's anemia patients. This repair pathway results in increased mutation frequency and altered mutational spectrum. [52] The second repair pathway requires replication fork convergence, breakage of the acetaldehyde crosslink, translesion synthesis by a Y-family DNA polymerase and homologous recombination. [52]

Aggravating factors

Alzheimer's disease

People with a genetic deficiency for the enzyme responsible for the conversion of acetaldehyde into acetic acid may have a greater risk of Alzheimer's disease. "These results indicate that the ALDH2 deficiency is a risk factor for LOAD [late-onset Alzheimer's disease] ..." [53]

Genetic conditions

A study of 818 heavy drinkers found that those exposed to more acetaldehyde than normal through a genetic variant of the gene encoding for ADH1C, ADH1C*1, are at greater risk of developing cancers of the upper gastrointestinal tract and liver. [54]


The drug disulfiram (Antabuse) inhibits acetaldehyde dehydrogenase, an enzyme that oxidizes the compound into acetic acid. Metabolism of ethanol forms acetaldehyde before acetaldehyde dehydrogenase forms acetic acid, but with the enzyme inhibited, acetaldehyde accumulates. If one consumes ethanol while taking disulfiram, the hangover effect of ethanol is felt more rapidly and intensely (disulfiram-alcohol reaction). As such, disulfiram is sometimes used as a deterrent for alcoholics wishing to stay sober. [42]

Sources of exposure

Indoor air

Acetaldehyde is a potential contaminant in workplace, indoors, and ambient environments. Moreover, the majority of humans spend more than 90% of their time in indoor environments, increasing any exposure and the risk to human health. [55]

In a study in France, the mean indoor concentration of acetaldehydes measured in 16 homes was approximately seven times higher than the outside acetaldehyde concentration. The living room had a mean of 18.1±17.5 μg m−3 and the bedroom was 18.2±16.9 μg m−3, whereas the outdoor air had a mean concentration of 2.3±2.6 μg m−3.[ citation needed ]

It has been concluded that volatile organic compounds (VOC) such as benzene, formaldehyde, acetaldehyde, toluene, and xylenes have to be considered priority pollutants with respect to their health effects. It has been pointed that in renovated or completely new buildings, the VOCs concentration levels are often several orders of magnitude higher. The main sources of acetaldehydes in homes include building materials, laminate, PVC flooring, varnished wood flooring, and varnished cork/pine flooring (found in the varnish, not the wood). It is also found in plastics, oil-based and water-based paints, in composite wood ceilings, particle-board, plywood, treated pine wood, and laminated chipboard furniture. [56]

Outdoor air

The use of acetaldehyde is widespread in different industries, and it may be released into waste water or the air during production, use, transportation and storage. Sources of acetaldehyde include fuel combustion emissions from stationary internal combustion engines and power plants that burn fossil fuels, wood, or trash, oil and gas extraction, refineries, cement kilns, lumber and wood mills and paper mills. [57] Acetaldehyde is also present in automobile and diesel exhaust. [58] As a result, acetaldehyde is "one of the most frequently found air toxics with cancer risk greater than one in a million". [14]

Tobacco smoke

Natural tobacco polysaccharides, including cellulose, have been shown to be the primary precursors making acetaldehyde a significant constituent of tobacco smoke. [59] [60] It has been demonstrated to have a synergistic effect with nicotine in rodent studies of addiction. [61] [62] Acetaldehyde is also the most abundant carcinogen in tobacco smoke; it is dissolved into the saliva while smoking.

Cannabis smoke

Acetaldehyde has been found in cannabis smoke. This finding emerged through the use of new chemical techniques that demonstrated the acetaldehyde present was causing DNA damage in laboratory settings. [63]

Alcohol consumption

Many microbes produce acetaldehyde from ethanol, but they have a lower capacity to eliminate the acetaldehyde, which can lead to the accumulation of acetaldehyde in saliva, stomach acid, and intestinal contents. Fermented food and many alcoholic beverages can also contain significant amounts of acetaldehyde. Acetaldehyde, derived from mucosal or microbial oxidation of ethanol, tobacco smoke, and diet, appears to act as a cumulative carcinogen in the upper digestive tract of humans. [64] According to European Commission's Scientific Committee on Consumer Safety's (SCCS) "Opinion on Acetaldehyde" (2012) the cosmetic products special risk limit is 5 mg/L and acetaldehyde should not be used in mouth-washing products. [65]


Acetaldehyde can be produced by the photo-oxidation of polyethylene terephthalate (PET), via a Type II Norrish reaction. [66]

Poly(ethylene terephthalate) - Type II Norrish to acetaldehyde.png

Although the levels produced by this process are minute acetaldehyde has an exceedingly low taste/odor threshold of around 20–40 ppb and can cause an off-taste in bottled water. [67] The level at which an average consumer could detect acetaldehyde is still considerably lower than any toxicity. [68]

Candida overgrowth

Candida albicans in patients with potentially carcinogenic oral diseases has been shown to produce acetaldehyde in quantities sufficient to cause problems. [69]

See also

Related Research Articles

<span class="mw-page-title-main">Aldehyde</span> Organic compound containing the functional group R−CH=O

In organic chemistry, an aldehyde is an organic compound containing a functional group with the structure R−CH=O. The functional group itself can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are a common motif in many chemicals important in technology and biology.

A dehydrogenase is an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron acceptor, usually NAD+/NADP+ or a flavin coenzyme such as FAD or FMN. Like all catalysts, they catalyze reverse as well as forward reactions, and in some cases this has physiological significance: for example, alcohol dehydrogenase catalyzes the oxidation of ethanol to acetaldehyde in animals, but in yeast it catalyzes the production of ethanol from acetaldehyde.

<span class="mw-page-title-main">Disulfiram</span> Chemical compound

Disulfiram is a medication used to support the treatment of chronic alcoholism by producing an acute sensitivity to ethanol. Disulfiram works by inhibiting the enzyme aldehyde dehydrogenase, causing many of the effects of a hangover to be felt immediately following alcohol consumption. Disulfiram plus alcohol, even small amounts, produces flushing, throbbing in the head and neck, a throbbing headache, respiratory difficulty, nausea, copious vomiting, sweating, thirst, chest pain, palpitation, dyspnea, hyperventilation, fast heart rate, low blood pressure, fainting, marked uneasiness, weakness, vertigo, blurred vision, and confusion. In severe reactions there may be respiratory depression, cardiovascular collapse, abnormal heart rhythms, heart attack, acute congestive heart failure, unconsciousness, convulsions, and death.

<span class="mw-page-title-main">Acetaldehyde dehydrogenase</span> Class of enzymes

Acetaldehyde dehydrogenases are dehydrogenase enzymes which catalyze the conversion of acetaldehyde into acetyl-CoA. This can be summarized as follows:

<span class="mw-page-title-main">Vinyl alcohol</span> Chemical compound

Vinyl alcohol, also called ethenol or ethylenol, is the simplest enol. With the formula CH2CHOH, it is a labile compound that converts to acetaldehyde immediately upon isolation near room temperature. It is not a practical precursor to any compound.

Paraldehyde is the cyclic 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 colourless liquid, it is sparingly soluble in water and highly soluble in ethanol. Paraldehyde slowly oxidizes in air, turning brown and producing an odour of acetic acid. It attacks most plastics and rubbers and should be kept in glass bottles.

<span class="mw-page-title-main">Acetic anhydride</span> Organic compound with formula (CH₃CO)₂O

Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula (CH3CO)2O. Commonly abbreviated Ac2O, it is the simplest isolable anhydride of a carboxylic acid and is widely used as a reagent in organic synthesis. It is a colorless liquid that smells strongly of acetic acid, which is formed by its reaction with moisture in the air.

<span class="mw-page-title-main">Alcohol flush reaction</span> Effect of alcohol consumption on the human body

Alcohol flush reaction is a condition in which a person develops flushes or blotches associated with erythema on the face, neck, shoulders, ears, and in some cases, the entire body after consuming alcoholic beverages. The reaction is the result of an accumulation of acetaldehyde, a metabolic byproduct of the catabolic metabolism of alcohol, and is caused by an aldehyde dehydrogenase 2 deficiency.

The Bouveault–Blanc reduction is a chemical reaction in which an ester is reduced to primary alcohols using absolute ethanol and sodium metal. It was first reported by Louis Bouveault and Gustave Louis Blanc in 1903. Bouveault and Blanc demonstrated the reduction of ethyl oleate and n-butyl oleate to oleyl alcohol. Modified versions of which were subsequently refined and published in Organic Syntheses.

<span class="mw-page-title-main">Fomepizole</span> Medication

Fomepizole, also known as 4-methylpyrazole, is a medication used to treat methanol and ethylene glycol poisoning. It may be used alone or together with hemodialysis. It is given by injection into a vein.

<span class="mw-page-title-main">Aldehyde dehydrogenase</span> Group of enzymes

Aldehyde dehydrogenases are a group of enzymes that catalyse the oxidation of aldehydes. They convert aldehydes to carboxylic acids. The oxygen comes from a water molecule. To date, nineteen ALDH genes have been identified within the human genome. These genes participate in a wide variety of biological processes including the detoxification of exogenously and endogenously generated aldehydes.

Ethanol, an alcohol found in nature and in alcoholic drinks, is metabolized through a complex catabolic metabolic pathway. In humans, several enzymes are involved in processing ethanol first into acetaldehyde and further into acetic acid and acetyl-CoA. Once acetyl-CoA is formed, it becomes a substrate for the citric acid cycle ultimately producing cellular energy and releasing water and carbon dioxide. Due to differences in enzyme presence and availability, human adults and fetuses process ethanol through different pathways. Gene variation in these enzymes can lead to variation in catalytic efficiency between individuals. The liver is the major organ that metabolizes ethanol due to its high concentration of these enzymes.

<span class="mw-page-title-main">ALDH2</span> Enzyme

Aldehyde dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the ALDH2 gene located on chromosome 12. ALDH2 belongs to the aldehyde dehydrogenase family of enzymes. Aldehyde dehydrogenase is the second enzyme of the major oxidative pathway of alcohol metabolism. ALDH2 has a low Km for acetaldehyde, and is localized in mitochondrial matrix. The other liver isozyme, ALDH1, localizes to the cytosol.

<span class="mw-page-title-main">Thiuram disulfide</span> Class of chemical compounds

Thiuram disulfides are a class of organosulfur compounds with the formula (R2NCSS)2. Many examples are known, but popular ones include R = Me and R = Et. They are disulfides obtained by oxidation of the dithiocarbamates. These compounds are used in sulfur vulcanization of rubber as well as in the manufacture of pesticides and drugs. They are typically white or pale yellow solids that are soluble in organic solvents.

<span class="mw-page-title-main">Coprine</span> Chemical compound

Coprine is a mycotoxin. It was first isolated from common inkcap. It occurs in mushrooms in the genera Coprinopsis. When combined with alcohol, it causes "Coprinus syndrome". It inhibits the enzyme acetaldehyde dehydrogenase, which is involved in the metabolism of alcohol. This inhibition leads to a buildup of acetaldehyde, causing an alcohol flush reaction. Because of this, the mushroom is commonly referred to as Tippler's Bane.

<span class="mw-page-title-main">Tryptophol</span> Chemical compound

Tryptophol is an aromatic alcohol that induces sleep in humans. It is found in wine as a secondary product of ethanol fermentation. It was first described by Felix Ehrlich in 1912. It is also produced by the trypanosomal parasite in sleeping sickness.

<span class="mw-page-title-main">1-Aminoethanol</span> Chemical compound

1-Aminoethanol is an organic compound with the formula CH3CH(NH2)OH. It is classified as an alkanolamine. Specifically, it is a structural isomer of 2-aminoethanol (ethanolamine). These two compounds differ in the position of the amino group. Since the central carbon atom in 1-aminoethanol has four different substituents, the compound has two stereoisomers. Unlike 2-aminoethanol, which is of considerable importance in commerce, 1-aminoethanol is not encountered as a pure material and is mainly of theoretical interest.

<span class="mw-page-title-main">Alcohol intolerance</span> Medical condition

Alcohol intolerance is due to a genetic polymorphism of the aldehyde dehydrogenase enzyme, which is responsible for the metabolism of acetaldehyde. This polymorphism is most often reported in patients of East Asian descent. Alcohol intolerance may also be an associated side effect of certain drugs such as disulfiram, metronidazole, or nilutamide. Skin flushing and nasal congestion are the most common symptoms of intolerance after alcohol ingestion. It may also be characterized as intolerance causing hangover symptoms similar to the "disulfiram-like reaction" of aldehyde dehydrogenase deficiency or chronic fatigue syndrome. Severe pain after drinking alcohol may indicate a more serious underlying condition.

<span class="mw-page-title-main">Disulfiram-like drug</span> Drug that causes an adverse reaction to alcohol

A disulfiram-like drug is a drug that causes an adverse reaction to alcohol leading to nausea, vomiting, flushing, dizziness, throbbing headache, chest and abdominal discomfort, and general hangover-like symptoms among others. These effects are caused by accumulation of acetaldehyde, a major but toxic metabolite of alcohol formed by the enzyme alcohol dehydrogenase. The reaction has been variously termed a disulfiram-like reaction, alcohol intolerance, and acetaldehyde syndrome.

<span class="mw-page-title-main">Alda-1</span> Organic compound

Alda-1 is an organic compound that enhances the enzymatic activity of human ALDH2. Alda-1 has been proposed as a potential treatment for the alcohol flush reaction experienced by people with genetically deficient ALDH2.


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