The Info List - Acetone

(systematically named propanone) is the organic compound with the formula (CH3)2CO.[12] It is a colorless, volatile, flammable liquid, and is the simplest and smallest ketone. Acetone
is miscible with water and serves as an important solvent in its own right, typically for cleaning purposes in laboratories. About 6.7 million tonnes were produced worldwide in 2010, mainly for use as a solvent and production of methyl methacrylate and bisphenol A.[13][14] It is a common building block in organic chemistry. Familiar household uses of acetone are as the active ingredient in nail polish remover, and as paint thinner. Acetone
is produced and disposed of in the human body through normal metabolic processes. It is normally present in blood and urine. People with diabetes produce it in larger amounts. Reproductive toxicity tests show that it has low potential to cause reproductive problems. Pregnant women, nursing mothers and children have higher levels of acetone.[15] Ketogenic diets that increase ketones (acetone, β-hydroxybutyric acid and acetoacetic acid) in the blood are used to counter epileptic attacks in infants and children who suffer from recalcitrant refractory epilepsy.


1 History 2 Metabolism

2.1 Biosynthesis 2.2 Metabolic use

3 Production

3.1 Current method 3.2 Older methods

4 Uses

4.1 Solvent 4.2 Chemical intermediate 4.3 Laboratory 4.4 Medical and cosmetic uses 4.5 Domestic and other niche uses

5 Safety

5.1 Flammability 5.2 Acetone
peroxide 5.3 Health information

5.3.1 Toxicology

6 Environmental effects 7 Extraterrestrial occurrence 8 References 9 External links

History[edit] Acetone
was first produced by alchemists during the late Middle Ages via the dry distillation of metal acetates (e.g., lead acetate, which produced "spirit of Saturn" (since the alchemical symbol for lead was also the astrological symbol for the planet Saturn)).[16] In 1832, French chemist Jean-Baptiste Dumas
Jean-Baptiste Dumas
and German chemist Justus von Liebig determined the empirical formula for acetone.[17][18] In 1833, the French chemist Antoine Bussy
Antoine Bussy
named acetone by adding the suffix -one to the stem of the corresponding acid (viz, acetic acid).[19] By 1852, English chemist Alexander William Williamson realized that acetone was methyl acetyl;[20] the following year, the French chemist Charles Frédéric Gerhardt
Charles Frédéric Gerhardt
concurred.[21] In 1865, the German chemist August Kekulé
August Kekulé
published the modern structural formula for acetone.[22][23][24] During World War I, Chaim Weizmann
Chaim Weizmann
developed the process for industrial production of acetone (Weizmann Process).[25] Metabolism[edit] See also: Ketosis Biosynthesis[edit] Small amounts of acetone are produced in the body by the decarboxylation of ketone bodies. Certain dietary patterns, including prolonged fasting and high-fat low-carbohydrate dieting, can produce ketosis, in which acetone is formed in body tissue. Certain health conditions, such as alcoholism and diabetes, can produce ketoacidosis, uncontrollable ketosis that leads to a sharp, and potentially fatal, increase in the acidity of the blood. Since it is a byproduct of fermentation, acetone is a byproduct of the distillery industry. Metabolic use[edit] Although some biochemistry textbooks and current research publications[26] indicate that acetone cannot be metabolized, there is evidence to the contrary, some dating back thirty years. Acetone
can be produced from the oxidation of ingested isopropanol, or from the spontaneous/enzymatic breakdown of acetoacetate (a ketone body) in ketotic individuals. It can then be metabolized either by CYP2E1
via methylglyoxal to D-lactate and pyruvate, and ultimately glucose/energy, or by a different pathway via propylene glycol to pyruvate, lactate, acetate (usable for energy) and propionaldehyde.[27][28][29] Production[edit] In 2010, the worldwide production capacity for acetone was estimated at 6.7 million tonnes per year.[30] With 1.56 million tonnes per year, the United States had the highest production capacity,[31] followed by Taiwan
and mainland China. The largest producer of acetone is INEOS Phenol, owning 17% of the world's capacity, with also significant capacity (7–8%) by Mitsui, Sunoco
and Shell in 2010.[30] INEOS Phenol
also owns the world's largest production site (420,000 tonnes/annum) in Beveren
(Belgium). Spot price of acetone in summer 2011 was 1100–1250 USD/tonne in the United States.[32] Current method[edit] Acetone
is produced directly or indirectly from propylene. Approximately 83% of acetone is produced via the cumene process;[14] as a result, acetone production is tied to phenol production. In the cumene process, benzene is alkylated with propylene to produce cumene, which is oxidized by air to produce phenol and acetone:

Other processes involve the direct oxidation of propylene (Wacker-Hoechst process), or the hydration of propylene to give 2-propanol, which is oxidized to acetone.[14] Older methods[edit] Previously, acetone was produced by the dry distillation of acetates, for example calcium acetate in ketonic decarboxylation.

Ca(CH3COO)2 → CaO(s) + CO2(g) + (CH3)2CO (v)

After that time, during World War I, acetone was produced using acetone-butanol-ethanol fermentation with Clostridium acetobutylicum bacteria, which was developed by Chaim Weizmann
Chaim Weizmann
(later the first president of Israel) in order to help the British war effort,[14] in the preparation of Cordite.[33] This acetone-butanol-ethanol fermentation was eventually abandoned when newer methods with better yields were found.[14] Uses[edit] About a third of the world's acetone is used as a solvent, and a quarter is consumed as acetone cyanohydrin, a precursor to methyl methacrylate.[13] Solvent[edit] Acetone
is a good solvent for many plastics and some synthetic fibers. It is used for thinning polyester resin, cleaning tools used with it, and dissolving two-part epoxies and superglue before they harden. It is used as one of the volatile components of some paints and varnishes. As a heavy-duty degreaser, it is useful in the preparation of metal prior to painting. It is also useful for high reliability soldering applications to remove rosin flux after soldering is complete; this helps to prevent the rusty bolt effect. Acetone
is used as a solvent by the pharmaceutical industry and as a denaturant in denatured alcohol.[34] Acetone
is also present as an excipient in some pharmaceutical drugs.[35] Although itself flammable, acetone is used extensively as a solvent for the safe transportation and storage of acetylene, which cannot be safely pressurized as a pure compound. Vessels containing a porous material are first filled with acetone followed by acetylene, which dissolves into the acetone. One liter of acetone can dissolve around 250 liters of acetylene at a pressure of 10 bar.[36][37] Chemical intermediate[edit] Acetone
is used to synthesize methyl methacrylate. It begins with the initial conversion of acetone to acetone cyanohydrin:

(CH3)2CO + HCN → (CH3)2C(OH)CN

In a subsequent step, the nitrile is hydrolyzed to the unsaturated amide, which is esterified:

(CH3)2C(OH)CN + CH3OH → CH2=(CH3)CCO2CH3 + NH3

The third major use of acetone (about 20%)[13] is synthesizing bisphenol A. Bisphenol A
Bisphenol A
is a component of many polymers such as polycarbonates, polyurethanes, and epoxy resins. The synthesis involves the condensation of acetone with phenol:

(CH3)2CO + 2 C6H5OH → (CH3)2C(C6H4OH)2 + H2O

Many millions of kilograms of acetone are consumed in the production of the solvents methyl isobutyl alcohol and methyl isobutyl ketone. These products arise via an initial aldol condensation to give diacetone alcohol.[14]

2 (CH3)2CO → (CH3)2C(OH)CH2C(O)CH3

Laboratory[edit] In the laboratory, acetone is used as a polar, aprotic solvent in a variety of organic reactions, such as SN2 reactions. The use of acetone solvent is critical for the Jones oxidation. It does not form an azeotrope with water (see azeotrope (data)).[38] It is a common solvent for rinsing laboratory glassware because of its low cost and volatility. Despite its common use as a supposed drying agent, it is not effective except by bulk displacement and dilution. Acetone
can be cooled with dry ice to −78 °C without freezing; acetone/dry ice baths are commonly used to conduct reactions at low temperatures. Acetone
is fluorescent under ultraviolet light, and its vapor can be used as a fluorescent tracer in fluid flow experiments.[39] Medical and cosmetic uses[edit] Acetone
is used in a variety of general medical and cosmetic applications and is also listed as a component in food additives and food packaging and also in nail polish remover. Dermatologists use acetone with alcohol for acne treatments to peel dry skin. Acetone
is commonly used in chemical peeling. Common agents used today for chemical peels are salicylic acid, glycolic acid, 30% salicylic acid in ethanol, and trichloroacetic acid (TCA). Prior to chemexfoliation, the skin is cleaned and excess fat removed in a process called defatting. Acetone, Septisol, or a combination of these agents is commonly used in this process.[citation needed] Domestic and other niche uses[edit] Acetone
is often the primary component in cleaning agents such as nail polish remover. Acetone
is a component of superglue remover and easily removes residues from glass and porcelain. Make-up artists use acetone to remove skin adhesive from the netting of wigs and moustaches by immersing the item in an acetone bath, then removing the softened glue residue with a stiff brush. Acetone
is often used for vapor polishing of printing artifacts on 3D-printed models printed with ABS plastic. The technique, called acetone vapor bath smoothing, involves placing the printed part in a sealed chamber containing a small amount of acetone, and heating to around 80 degrees Celsius for 10 minutes. This creates a vapor of acetone in the container. The acetone condenses evenly all over the part, causing the surface to soften and liquefy. Surface tension then smooths the semi-liquid plastic. When the part is removed from the chamber, the acetone component evaporates leaving a glassy-smooth part free of striation, patterning, and visible layer edges, common features in untreated 3D printed parts.[40] Low-grade acetone is also commonly used in academic laboratory settings as a glassware rinsing agent for removing residue and solids before a final wash.[41] Safety[edit] Flammability[edit] The most hazardous property of acetone is its extreme flammability. At temperatures greater than acetone's flash point of −20 °C (−4 °F), air mixtures of between 2.5% and 12.8% acetone, by volume, may explode or cause a flash fire. Vapors can flow along surfaces to distant ignition sources and flash back. Static discharge may also ignite acetone vapors, though acetone has a very high ignition initiation energy point and therefore accidental ignition is rare. Even pouring or spraying acetone over red-glowing coal will not ignite it, due to the high concentration of vapour and the cooling effect of evaporation of the liquid.[42] It auto-ignites at 465 °C (869 °F). Auto-ignition temperature is also dependent upon the exposure time, thus at some tests it is quoted as 525 °C. Also, industrial acetone is likely to contain a small amount of water which also inhibits ignition. Acetone
peroxide[edit] Main article: acetone peroxide When oxidized, acetone forms acetone peroxide as a byproduct, which is a highly unstable, primary high explosive compound. It may be formed accidentally, e.g. when waste hydrogen peroxide is poured into waste solvent containing acetone. Due to its instability, it is rarely used, despite its simple chemical synthesis. Health information[edit] Acetone
has been studied extensively and is generally recognized to have low acute and chronic toxicity if ingested and/or inhaled.[43] Acetone
is not currently regarded as a carcinogen, a mutagenic chemical nor a concern for chronic neurotoxicity effects.[42] Acetone
can be found as an ingredient in a variety of consumer products ranging from cosmetics to processed and unprocessed foods. Acetone
has been rated as a generally recognized as safe (GRAS) substance when present in beverages, baked foods, desserts, and preserves at concentrations ranging from 5 to 8 mg/L.[43] Toxicology[edit] Acetone
is believed to exhibit only slight toxicity in normal use, and there is no strong evidence of chronic health effects if basic precautions are followed.[44] At very high vapor concentrations, acetone is irritating and, like many other solvents, may depress the central nervous system. It is also a severe irritant on contact with eyes, and a potential pulmonary aspiration risk. In one documented case, ingestion of a substantial amount of acetone led to systemic toxicity, although the patient eventually fully recovered.[45] Some sources estimate LD50 for human ingestion at 0.621 g/kg; LD50 inhalation by mice is given as 23 g/m3, over 4 hours.[46] Acetone
has been shown to have anticonvulsant effects in animal models of epilepsy, in the absence of toxicity, when administered in millimolar concentrations.[47] It has been hypothesized that the high-fat low-carbohydrate ketogenic diet used clinically to control drug-resistant epilepsy in children works by elevating acetone in the brain.[47]

EPA EPCRA Delisting (1995). EPA removed acetone from the list of "toxic chemicals" maintained under Section 313 of the Emergency Planning and Community Right to Know Act (EPCRA). In making that decision, EPA conducted an extensive review of the available toxicity data on acetone and found that acetone "exhibits acute toxicity only at levels that greatly exceed releases and resultant exposures", and further that acetone "exhibits low toxicity in chronic studies". Genotoxicity. Acetone
has been tested in more than two dozen in vitro and in vivo assays. These studies indicate that acetone is not genotoxic. Carcinogenicity. EPA in 1995 concluded, "There is currently no evidence to suggest a concern for carcinogenicity". (EPCRA Review, described in Section 3.3). NTP scientists have recommended against chronic toxicity/carcinogenicity testing of acetone because "the prechronic studies only demonstrated a very mild toxic response at very high doses in rodents". Neurotoxicity and Developmental Neurotoxicity. The neurotoxic potential of both acetone and isopropanol, the metabolic precursor of acetone, have been extensively studied. These studies demonstrate that although exposure to high doses of acetone may cause transient central nervous system effects, acetone is not a neurotoxicant. A guideline developmental neurotoxicity study has been conducted with isopropanol, and no developmental neurotoxic effects were identified, even at the highest dose tested. (SIAR, pp. 1, 25, 31). Environmental. When the EPA exempted acetone from regulation as a volatile organic compound (VOC) in 1995, EPA stated that this exemption would "contribute to the achievement of several important environmental goals and would support EPA's pollution prevention efforts". 60 Fed. Reg. 31,634 (June 16, 1995). 60 Fed. Reg. 31,634 (June 16, 1995). EPA noted that acetone could be used as a substitute for several compounds that are listed as hazardous air pollutants (HAP) under section 112 of the Clean Air Act.

Environmental effects[edit] Although acetone occurs naturally in the environment in plants, trees, volcanic gases, forest fires, and as a product of the breakdown of body fat,[48] the majority of the acetone released into the environment is of industrial origin. Acetone
evaporates rapidly, even from water and soil. Once in the atmosphere, it has a 22-day half-life and is degraded by UV light via photolysis (primarily into methane and ethane.[49]) Consumption by microorganisms contributes to the dissipation of acetone in soil, animals, or waterways.[48] The LD50 of acetone for fish is 8.3 g/L of water (or about 1%) over 96 hours, and its environmental half-life in water is about 1 to 10 days. Acetone may pose a significant risk of oxygen depletion in aquatic systems due to the microbial consumption.[50] Extraterrestrial occurrence[edit] On 30 July 2015, scientists reported that upon the first touchdown of the Philae lander on comet 67P's surface, measurements by the COSAC and Ptolemy instruments revealed sixteen organic compounds, four of which were seen for the first time on a comet, including acetamide, acetone, methyl isocyanate, and propionaldehyde.[51][52][53] References[edit]

^ The Merck Index, 15th Ed. (2013), p. 13, Acetone
Monograph 65, O'Neil: The Royal Society of Chemistry.(subscription required) ^ a b c "Acetone". NIST Chemistry WebBook. USA: National Institute of Standards and Technology.  ^ Klamt, Andreas (2005). COSMO-RS: From Quantum Chemistry to Fluid Phase Thermodynamics and Drug Design. Elsevier. pp. 92–94. ISBN 978-0-444-51994-8.  ^ Ash, Michael; Ash, Irene (2004). Handbook of preservatives. Synapse Information Resources, Inc. p. 369. ISBN 1-890595-66-7.  ^ Myers, Richard L. (2007). The 100 Most Important Chemical Compounds: A Reference Guide. Greenwood. pp. 4–6. ISBN 978-0-313-08057-9.  ^ a b c d "NIOSH Pocket Guide to Chemical Hazards #0260". National Institute for Occupational Safety and Health (NIOSH).  ^ a b Properties of substance: acetone. chemister.ru. ^ Acetone
in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD), http://webbook.nist.gov (retrieved 2014-05-11) ^ a b Lide, David R. (ed) (2003). CRC Handbook of Chemistry and Physics, 84th Edition. CRC Press. Boca Raton, Florida; Section 3, Physical Constants of Organic Compounds. ^ Working with modern hydrocarbon and oxygenated solvents: a guide to flammability Archived 2009-06-01 at the Wayback Machine. American Chemistry Council Solvents Industry Group, pg. 7, January 2008 ^ a b c "Acetone". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).  ^ Allen, P. W.; Bowen, H. J. M.; Sutton, L. E.; Bastiansen, O. (1952). "The molecular structure of acetone". Transactions of the Faraday Society. 48: 991. doi:10.1039/TF9524800991.  ^ a b c Acetone, World Petrochemicals report, January 2010 ^ a b c d e f Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. ^ American Chemistry Council, Acetone
VCCEP Submission, September 10, 2003, page 9. ^ Gorman, Mel & Doering, Charles (1959). "History of the structure of acetone". Chymia. 5: 202–208. JSTOR 27757186.  ^ Dumas, J. (1832) "Sur l'esprit pyro-acétique" (On pyro-acetic spirit), Annales de Chimie et de Physique, 2nd series, 49 : 208–210. ^ Liebig, Justus (1832) "Sur les combinaisons produites par l'action du gas oléfiant et l'esprit acétique" (On compounds produced by the action of ethylene and acetic spirit), Annales de Chimie et de Physique, 2nd series, 49 : 146–204 (especially 193–204). ^ Bussy, Antoine (1833) "De quelques Produits nouveaux obtenus par l’action des Alcalis sur les Corps gras à une haute température"[permanent dead link] (On some new products obtained by the action of alkalies on fatty substances at a high temperature), Annales de Chimie et de Physique, 2nd series, 53 : 398–412 ; see footnote on p. 409[permanent dead link], continued from p. 408. ^ Williamson, A. W. (1852) "On Etherification," Journal of the Chemical Society, 4 : 229–239 ; see especially pp. 237–239. ^ Gerhardt, Charles (1853) "Researches sur les acids organiques anhydres" (Research on anhydrous organic acids), Annales de Chimie et de Physique, 3rd series, 37 : 285–342 ; see p. 339.[permanent dead link] ^ Kekulé, Auguste (1865) "Sur la constitution des substances aromatiques,"[permanent dead link] Bulletin de la Société chimique de Paris, 1 : 98–110 ; see especially p. 110.[permanent dead link] ^ Kekulé, Auguste (1866) "Untersuchungen über aromatischen Verbindungen" (Investigations into aromatic compounds), Annalen der Chemie und Pharmacie, 137 : 129–196 ; see especially pp. 143–144.[permanent dead link] ^ Johann Josef Loschmidt had presented the structure of acetone in 1861, but his privately published booklet received little attention. See: J. Loschmidt, Chemische Studien (Vienna, Austria-Hungary: Carl Gerold's Sohn, 1861). ^ Chaim Weizmann. chemistryexplained.com ^ Vujasinovic, M; Kocar, M; Kramer, K; Bunc, M; Brvar, M (2007). "Poisoning with 1-propanol and 2-propanol". Human & Experimental Toxicology. 26 (12): 975. doi:10.1177/0960327107087794.  ^ Glew, Robert H (2010). "You Can Get There From Here: Acetone, Anionic Ketones and Even- Carbon
Fatty Acids can Provide Substrates for Gluconeogenesis". Nig. J. Physiol. Sci. 25: 2–4.  ^ Miller DN, Bazzano G; Bazzano (1965). "Propanediol metabolism and its relation to lactic acid metabolism". Ann NY Acad Sci. 119 (3): 957–973. Bibcode:1965NYASA.119..957M. doi:10.1111/j.1749-6632.1965.tb47455.x. PMID 4285478.  ^ Ruddick JA (1972). "Toxicology, metabolism, and biochemistry of 1,2-propanediol". Toxicol App Pharmacol. 21: 102–111. doi:10.1016/0041-008X(72)90032-4.  ^ a b Greiner, Camara; Funada, C (June 2010). "CEH Marketing Research Report: ACETONE". Chemical Economics Handbook. SRI consulting. Retrieved 2 September 2016. (subscription required) ^ " Acetone
Uses and Market Data". ICIS.com. October 2010. Retrieved 2011-03-21.  ^ Acetone
(US Gulf) Price Report – Chemical pricing information. ICIS Pricing. Retrieved on 2012-11-26. ^ Wittcoff, M.M. Green ; H.A. (2003). Organic chemistry principles and industrial practice (1. ed., 1. reprint. ed.). Weinheim: Wiley-VCH. p. 4. ISBN 3-527-30289-1.  ^ Weiner, Myra L.; Lois A. Kotkoskie (1999). Excipient Toxicity and Safety. p. 32. ISBN 978-0-8247-8210-8.  ^ Inactive Ingredient Search for Approved Drug Products, FDA/Center for Drug Evaluation and Research ^ Mine Safety and Health Administration (MSHA) – Safety Hazard Information – Special
Hazards of Acetylene. Msha.gov. Retrieved on 2012-11-26. ^ History – Acetylene
dissolved in acetone. Aga.com. Retrieved on 2012-11-26. ^ What is an Azeotrope?. Solvent—recycling.com. Retrieved on 2012-11-26. ^ Lozano, A.; Yip, B.; Hanson, R.K. (1992). "Acetone: a tracer for concentration measurements in gaseous flows by planar laser-induced fluorescence". Exp. Fluids. 13 (6): 369–376. Bibcode:1992ExFl...13..369L. doi:10.1007/BF00223244.  ^ "Quality Finish 3D Prints with Acetone". instructables.com ^ "Cleaning Glassware" (PDF). Wesleyan University. September 2009. Retrieved July 7, 2016.  ^ a b Acetone
MSDS. Hazard.com (1998-04-21). Retrieved on 2012-11-26. ^ a b "SIDS Initial Assessment Report: Acetone" (PDF). Environmental Protection Agency.  ^ Basic Information on Acetone. Ccohs.ca (1999-02-19). Retrieved on 2012-11-26. ^ Canadian Centre for Occupational Health and Safety. "Health Effects of Acetone". Archived from the original on 17 October 2008. Retrieved 2008-10-21.  ^ Safety (MSDS) data for propanone. sciencelab.com/msds. Retrieved on 2018-03-19 ^ a b Likhodii SS, Serbanescu I, Cortez MA, Murphy P, Snead OC, Burnham WM (2003). " Anticonvulsant
properties of acetone, a brain ketone elevated by the ketogenic diet". Ann Neurol. 54 (2): 219–226. doi:10.1002/ana.10634. PMID 12891674.  ^ a b Acetone, Agency for Toxic Substances and Disease Registry ToxFAQs, 1995 ^ Darwent, B. deB.; Allard, M. J.; Hartman, M. F.; Lange, L. J. (1960). "The Photolysis of Acetone". Journal of Physical Chemistry. 64 (12): 1847–1850. doi:10.1021/j100841a010.  ^ Safety Data Sheet Acetone
Archived 2009-03-20 at the Wayback Machine.. jmloveridge.com. Retrieved on 2012-11-26. ^ Jordans, Frank (30 July 2015). "Philae probe finds evidence that comets can be cosmic labs". The Washington Post. Associated Press. Retrieved 30 July 2015.  ^ "Science on the Surface of a Comet". European Space Agency. 30 July 2015. Retrieved 30 July 2015.  ^ Bibring, J.-P.; Taylor, M.G.G.T.; Alexander, C.; Auster, U.; Biele, J.; Finzi, A. Ercoli; Goesmann, F.; Klingehoefer, G.; Kofman, W.; Mottola, S.; Seidenstiker, K.J.; Spohn, T.; Wright, I. (31 July 2015). "Philae's First Days on the Comet
– Introduction to Special
Issue". Science. 349 (6247): 493. Bibcode:2015Sci...349..493B. doi:10.1126/science.aac5116. PMID 26228139. Retrieved 30 July 2015. 

External links[edit]

Wikimedia Commons has media related to Acetone.

International Chemical Safety Card 0087 NIOSH Pocket Guide to Chemical Hazards Acetone
Safety Data Sheet (SDS) Hazardous substances databank entry at the national library of medicine SIDS Initial Assessment Report for Acetone
from the Organisation for Economic Co-operation and Development (OECD) Calculation of vapor pressure, liquid density, dynamic liquid viscosity, surface tension of acetone

v t e

and steroid metabolic intermediates

Mevalonate pathway

to HMG-CoA

Acetyl-CoA Acetoacetyl-CoA HMB HMB-CoA HMG-CoA


Acetone Acetoacetic acid β-Hydroxybutyric acid


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Prephytoene diphosphate Phytoene

Non-mevalonate pathway


To Cholesterol

Farnesyl pyrophosphate Squalene 2,3-Oxidosqualene Lanosterol

Lanosterol Lathosterol 7-Dehydrocholesterol Cholesterol

Lanosterol Zymosterol 7-Dehydrodesmosterol Desmosterol Cholesterol

From Cholesterol (to steroids)

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See here instead.



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(cloretone) Ethanol
(alcohol) (alcoholic drink) Ethchlorvynol Isobutanol Isopropanol Menthol Methanol Methylpentynol Pentanol Petrichloral Propanol tert-Butanol (2M2P) tert-Pentanol (2M2B) Tribromoethanol Trichloroethanol Triclofos Trifluoroethanol


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2-Oxoquazepam 3-Hydroxyphenazepam Adinazolam Alprazolam Arfendazam Avizafone Bentazepam Bretazenil Bromazepam Brotizolam Camazepam Carburazepam Chlordiazepoxide Ciclotizolam Cinazepam Cinolazepam Clazolam Climazolam Clobazam Clonazepam Clonazolam Cloniprazepam Clorazepate Clotiazepam Cloxazolam CP-1414S Cyprazepam Delorazepam Demoxepam Diazepam Diclazepam Doxefazepam Elfazepam Estazolam Ethyl carfluzepate Ethyl dirazepate Ethyl loflazepate Etizolam EVT-201 FG-8205 Fletazepam Flubromazepam Flubromazolam Fludiazepam Flunitrazepam Flunitrazolam Flurazepam Flutazolam Flutemazepam Flutoprazepam Fosazepam Gidazepam Halazepam Haloxazolam Iclazepam Imidazenil Irazepine Ketazolam Lofendazam Lopirazepam Loprazolam Lorazepam Lormetazepam Meclonazepam Medazepam Menitrazepam Metaclazepam Mexazolam Midazolam Motrazepam N-Desalkylflurazepam Nifoxipam Nimetazepam Nitrazepam Nitrazepate Nitrazolam Nordazepam Nortetrazepam Oxazepam Oxazolam Phenazepam Pinazepam Pivoxazepam Prazepam Premazepam Proflazepam Pyrazolam QH-II-66 Quazepam Reclazepam Remimazolam Rilmazafone Ripazepam Ro48-6791 Ro48-8684 SH-053-R-CH3-2′F Sulazepam Temazepam Tetrazepam Tolufazepam Triazolam Triflubazam Triflunordazepam
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6-Methylapigenin Ampelopsin
(dihydromyricetin) Apigenin Baicalein Baicalin Catechin EGC EGCG Hispidulin Linarin Luteolin Rc-OMe Skullcap constituents (e.g., baicalin) Wogonin


Etomidate Metomidate Propoxate


10-Methoxyyangonin 11-Methoxyyangonin 11-Hydroxyyangonin Desmethoxyyangonin 11-Methoxy-12-hydroxydehydrokavain 7,8-Dihydroyangonin Kavain 5-Hydroxykavain 5,6-Dihydroyangonin 7,8-Dihydrokavain 5,6,7,8-Tetrahydroyangonin 5,6-Dehydromethysticin Methysticin 7,8-Dihydromethysticin Yangonin


Acecarbromal Apronal
(apronalide) Bromisoval Carbromal Capuride Ectylurea

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Acebrochol Allopregnanolone
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(eltanolone) Progesterone Renanolone SAGE-105 SAGE-217 SAGE-324 SAGE-516 SAGE-689 SAGE-872 Testosterone THDOC


β-Carbolines: Abecarnil Gedocarnil Harmane SL-651,498 ZK-93423

Cyclopyrrolones: Eszopiclone Pagoclone Pazinaclone Suproclone Suriclone Zopiclone

Imidazopyridines: Alpidem DS-1 Necopidem Saripidem Zolpidem

Pyrazolopyrimidines: Divaplon Fasiplon Indiplon Lorediplon Ocinaplon Panadiplon Taniplon Zaleplon

Others: Adipiplon CGS-8216 CGS-9896 CGS-13767 CGS-20625 CL-218,872 CP-615,003 CTP-354 ELB-139 GBLD-345 Imepitoin JM-1232 L-838,417 Lirequinil
(Ro41-3696) NS-2664 NS-2710 NS-11394 Pipequaline ROD-188 RWJ-51204 SB-205,384 SX-3228 TGSC01AA TP-003 TPA-023 TP-13 U-89843A U-90042 Viqualine Y-23684


Fospropofol Propofol Thymol


Glutethimide Methyprylon Piperidione Pyrithyldione


Cartazolate Etazolate ICI-190,622 Tracazolate


Afloqualone Cloroqualone Diproqualone Etaqualone Mebroqualone Mecloqualone Methaqualone Methylmethaqualone Nitromethaqualone SL-164


Acetone Acetophenone Acetylglycinamide chloral hydrate Aliflurane Benzene Butane Butylene Centalun Chloral Chloral
betaine Chloral
hydrate Chloroform Cryofluorane Desflurane Dichloralphenazone Dichloromethane Diethyl ether Enflurane Ethyl chloride Ethylene Fluroxene Gasoline Halopropane Halothane Isoflurane Kerosine Methoxyflurane Methoxypropane Nitric oxide Nitrogen Nitrous oxide Norflurane Paraldehyde Propane Propylene Roflurane Sevoflurane Synthane Teflurane Toluene Trichloroethane (methyl chloroform) Trichloroethylene Vinyl ether


3-Hydroxybutanal α-EMTBL AA-29504 Avermectins (e.g., ivermectin) Bromide compounds (e.g., lithium bromide, potassium bromide, sodium bromide) Carbamazepine Chloralose Chlormezanone Clomethiazole DEABL Dihydroergolines (e.g., dihydroergocryptine, dihydroergosine, dihydroergotamine, ergoloid (dihydroergotoxine)) DS2 Efavirenz Etazepine Etifoxine Fenamates (e.g., flufenamic acid, mefenamic acid, niflumic acid, tolfenamic acid) Fluoxetine Flupirtine Hopantenic acid Lanthanum Lavender oil Lignans (e.g., 4-O-methylhonokiol, honokiol, magnolol, obovatol) Loreclezole Menthyl isovalerate
Menthyl isovalerate
(validolum) Monastrol Niacin Nicotinamide
(niacinamide) Org 25,435 Phenytoin Propanidid Retigabine
(ezogabine) Safranal Seproxetine Stiripentol Sulfonylalkanes (e.g., sulfonmethane (sulfonal), tetronal, trional) Terpenoids (e.g., borneol) Topiramate Valerian constituents (e.g., isovaleric acid, isovaleramide, valerenic acid, valerenol)

Unsorted benzodiazepine site positive modulators: α-Pinene MRK-409 (MK-0343) TCS-1105 TCS-1205

See also: Receptor/signaling modulators • GABA receptor modulators • GABA metabolism/transport modulators

v t e

Molecules detected in outer space



Aluminium monochloride Aluminium monofluoride Aluminium monoxide Argonium Carbon
monophosphide Carbon
monosulfide Carbon
monoxide Carborundum Cyanogen
radical Diatomic carbon Fluoromethylidynium Hydrogen
chloride Hydrogen
fluoride Hydrogen
(molecular) Hydroxyl radical Iron(II) oxide Magnesium monohydride cation Methylidyne radical Nitric oxide Nitrogen
(molecular) Nitrogen
monohydride Nitrogen
sulfide Oxygen
(molecular) Phosphorus monoxide Phosphorus mononitride Potassium chloride Silicon carbide Silicon mononitride Silicon monoxide Silicon monosulfide Sodium chloride Sodium iodide Sulfur monohydride Sulfur monoxide Titanium oxide


Aluminium hydroxide Aluminium isocyanide Amino radical Carbon
dioxide Carbonyl
sulfide CCP radical Chloronium Diazenylium Dicarbon monoxide Disilicon carbide Ethynyl radical Formyl radical Hydrogen cyanide
Hydrogen cyanide
(HCN) Hydrogen
isocyanide (HNC) Hydrogen
sulfide Hydroperoxyl Iron cyanide Isoformyl Magnesium cyanide Magnesium isocyanide Methylene radical N2H+ Nitrous oxide Nitroxyl Ozone Phosphaethyne Potassium cyanide Protonated molecular hydrogen Sodium cyanide Sodium hydroxide Silicon carbonitride c-Silicon dicarbide Silicon naphthalocyanine Sulfur dioxide Thioformyl Thioxoethenylidene Titanium dioxide Tricarbon Water

Four atoms

Acetylene Ammonia Cyanic acid Cyanoethynyl Cyclopropynylidyne Formaldehyde Fulminic acid HCCN Hydrogen
peroxide Hydromagnesium isocyanide Isocyanic acid Isothiocyanic acid Ketenyl Methylene amidogen Methyl radical Propynylidyne Protonated carbon dioxide Protonated hydrogen cyanide Silicon tricarbide Thioformaldehyde Tricarbon
monoxide Tricarbon
sulfide Thiocyanic acid

Five atoms

ion Butadiynyl Carbodiimide Cyanamide Cyanoacetylene Cyanoformaldehyde Cyanomethyl Cyclopropenylidene Formic acid Isocyanoacetylene Ketene Methane Methoxy
radical Methylenimine Propadienylidene Protonated formaldehyde Protonated formaldehyde Silane Silicon-carbide cluster

Six atoms

Acetonitrile Cyanobutadiynyl radical E-Cyanomethanimine Cyclopropenone Diacetylene Ethylene Formamide HC4N Ketenimine Methanethiol Methanol Methyl isocyanide Pentynylidyne Propynal Protonated cyanoacetylene

Seven atoms

Acetaldehyde Acrylonitrile

Vinyl cyanide

Cyanodiacetylene Ethylene
oxide Hexatriynyl radical Methylacetylene Methylamine Methyl isocyanate Vinyl alcohol

Eight atoms

Acetic acid Aminoacetonitrile Cyanoallene Ethanimine Glycolaldehyde Heptatrienyl radical Hexapentaenylidene Methylcyanoacetylene Methyl formate Propenal

Nine atoms

Acetamide Cyanohexatriyne Cyanotriacetylene Dimethyl ether Ethanol Methyldiacetylene Octatetraynyl radical Propene Propionitrile

Ten atoms or more

Acetone Benzene Benzonitrile Buckminsterfullerene
(C60 fullerene, buckyball) C70 fullerene Cyanodecapentayne Cyanopentaacetylene Cyanotetra-acetylene Ethylene
glycol Ethyl formate Methyl acetate Methyl-cyano-diacetylene Methyltriacetylene Propanal n-Propyl cyanide Pyrimidine

Deuterated molecules

Ammonia Ammonium
ion Formaldehyde Formyl radical Heavy water Hydrogen
cyanide Hydrogen
deuteride Hydrogen
isocyanide Methylacetylene N2D+ Trihydrogen cation


Anthracene Dihydroxyacetone Ethyl methyl ether Glycine Graphene H2NCO+ Linear C5 Naphthalene
cation Phosphine Pyrene Silylidine


Abiogenesis Astrobiology Astrochemistry Atomic and molecular astrophysics Chemical formula Circumstellar envelope Cosmic dust Cosmic ray Cosmochemistry Diffuse interstellar band Earliest known life forms Extraterrestrial life Extraterrestrial liquid water Forbidden mechanism Helium hydride ion Homochirality Intergalactic dust Interplanetary medium Interstellar medium Photodissociation region Iron–sulfur world theory Kerogen Molecules in stars Nexus for Exoplanet System Science Organic compound Outer space PAH world hypothesis Panspermia Polycyclic aromatic hydrocarbon
Polycyclic aromatic hydrocarbon
(PAH) RNA world hypothesis Spectroscopy Tholin

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