View source for Androstenone

{{distinguish|Androsterone|Androstenedione|5α-Androst-2-ene-17-one}}
{{Use dmy dates|date=November 2023}}
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 455367955
| ImageFile=Androstenone.svg
| ImageSize=200px
| ImageAlt = Skeletal formula of androstenone
| ImageFile1 = Androstenone-3D-balls.png
| ImageSize1 = 210
| ImageAlt1 = Ball-and-stick model of the androstenone molecule
| IUPACName = 5α-Androst-16-en-3-one
| SystematicName = (3a''S'',3b''R'',5a''S'',9a''S'',9b''S'',11a''R'')-9a,11a-Dimethyl-3,3a,3b,4,5,5a,6,8,9,9a,9b,10,11,11a-tetradecahydro-7''H''-cyclopenta[''a'']phenanthren-7-one
| OtherNames = 
|Section1={{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 5254715
| InChI = 1/C19H28O/c1-18-9-3-4-16(18)15-6-5-13-12-14(20)7-11-19(13,2)17(15)8-10-18/h3,9,13,15-17H,4-8,10-12H2,1-2H3/t13-,15-,16-,17-,18-,19-/m0/s1
| InChIKey = HFVMLYAGWXSTQI-QYXZOKGRBP
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C19H28O/c1-18-9-3-4-16(18)15-6-5-13-12-14(20)7-11-19(13,2)17(15)8-10-18/h3,9,13,15-17H,4-8,10-12H2,1-2H3/t13-,15-,16-,17-,18-,19-/m0/s1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = HFVMLYAGWXSTQI-QYXZOKGRSA-N
| CASNo_Ref = {{cascite|correct|??}}
| CASNo=18339-16-7
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = BWD3D5941J
| PubChem=6852393
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 37894
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 1309552
| SMILES = O=C4C[C@@H]3CC[C@@H]2[C@H](CC[C@@]1(/C=C\C[C@H]12)C)[C@@]3(C)CC4
}}
|Section2={{Chembox Properties
| C=19 | H=28 | O=1
| Appearance=
| Density=
| MeltingPt=
| BoilingPt=
| Solubility=
  }}
|Section3={{Chembox Hazards
| MainHazards=
| FlashPt=
| AutoignitionPt =
  }}
}}

'''Androstenone''' ('''5α-androst-16-en-3-one''') is a [[16-Androstene|16-androstene]] class [[steroid]]al pheromone. It is found in [[boar]]'s [[saliva]], [[celery]] [[cytoplasm]],{{citation needed|date=September 2016}} and [[truffle]] fungus.{{citation needed|date=September 2016}} Androstenone was the first [[mammal]]ian [[pheromone]] to be identified. It is found in high concentrations in the saliva of male pigs, and, when inhaled by a female pig that is [[in heat]], results in the female assuming the [[lordosis behavior|mating stance]]. Androstenone is the active ingredient in 'Boarmate', a commercial product made by [[DuPont]] sold to pig farmers to test sows for timing of [[artificial insemination]].<ref>{{cite journal |last1=Pierce |first1=John D. |last2=Cohen |first2=Adam B. |last3=Ulrich |first3=Patricia M. |title=Responsivity to Two Odorants, Androstenone and Amyl Acetate, and the Affective Impact of Odors on Interpersonal Relationships. |journal=Journal of Comparative Psychology |date=March 2004 |volume=118 |issue=1 |pages=14–19 |doi=10.1037/0735-7036.118.1.14 |pmid=15008668 }}</ref><ref>{{cite journal |last1=Dorries |first1=Kathleen M. |last2=Adkins-Regan |first2=Elizabeth |last3=Halpern |first3=Bruce P. |title=Sensitivity and Behavioral Responses to the Pheromone Androstenone Are Not Mediated by the Vomeronasal Organ in Domestic Pigs |journal=Brain, Behavior and Evolution |date=1997 |volume=49 |issue=1 |pages=53–62 |doi=10.1159/000112981 |pmid=8980852 }}</ref><ref name="Wysocki et al 1989">{{cite journal |last1=Wysocki |first1=C. J. |last2=Dorries |first2=K. M. |last3=Beauchamp |first3=G. K. |title=Ability to perceive androstenone can be acquired by ostensibly anosmic people. |journal=Proceedings of the National Academy of Sciences |date=1 October 1989 |volume=86 |issue=20 |pages=7976–7978 |doi=10.1073/pnas.86.20.7976 |pmid=2813372 |pmc=298195 |bibcode=1989PNAS...86.7976W |doi-access=free }}</ref><ref name="Wysocki & Beauchamp 1984">{{cite journal |last1=Wysocki |first1=C. J. |last2=Beauchamp |first2=G. K. |title=Ability to smell androstenone is genetically determined. |journal=Proceedings of the National Academy of Sciences |date=1 August 1984 |volume=81 |issue=15 |pages=4899–4902 |doi=10.1073/pnas.81.15.4899 |pmid=6589634 |pmc=391599 |bibcode=1984PNAS...81.4899W |doi-access=free }}</ref><ref>{{cite journal |last1=Bonneau |first1=M. |last2=Walstra |first2=P. |last3=Claudi-Magnussen |first3=C. |last4=Kempster |first4=A.J. |last5=Tornberg |first5=E. |last6=Fischer |first6=K. |last7=Diestre |first7=A. |last8=Siret |first8=F. |last9=Chevillon |first9=P. |last10=Claus |first10=R. |last11=Dijksterhuis |first11=G. |last12=Punter |first12=P. |last13=Matthews |first13=K.R. |last14=Agerhem |first14=H. |last15=Béague |first15=M.P. |last16=Oliver |first16=M.A. |last17=Gispert |first17=M. |last18=Weiler |first18=U. |last19=von Seth |first19=G. |last20=Leask |first20=H. |last21=Font i Furnols |first21=M. |last22=Homer |first22=D.B. |last23=Cook |first23=G.L. |title=An international study on the importance of androstenone and skatole for boar taint: IV. Simulation studies on consumer dissatisfaction with entire male pork and the effect of sorting carcasses on the slaughter line, main conclusions and recommendations |journal=Meat Science |date=March 2000 |volume=54 |issue=3 |pages=285–295 |doi=10.1016/s0309-1740(99)00105-9 |pmid=22060698 }}</ref>

==Biosynthesis==
Androstenone is [[biosynthesis|synthesized]] from [[androstadienone]] by [[5α-reductase]], and can be converted into [[3α-androstenol]] or [[3β-androstenol]] by [[3-ketosteroid reductase]].<ref name="JohannesWeusten1989">{{cite thesis |last1=Weusten |first1=J. J. A. M. |title=Biochemical pathways in human testicular steroidogenesis |date=1989 |hdl=2066/113615 |hdl-access=free }}</ref>

==Properties==
Depending upon the subject, androstenone can have an unpleasant, sweaty, urinous smell, a woody smell, or even a pleasant floral smell.<ref name="Wysocki et al 1989"/><ref>{{cite news |title=Sniffers' genes dictate if sweat smells sweet |url=https://www.newscientist.com/article/mg19526225-600-sniffers-genes-dictate-if-sweat-smells-sweet/ |work=New Scientist |date=19 September 2007 }}</ref><ref>{{cite news |last1=Steenhuysen |first1=Julie |title=Stinky? It's not his sweat, it's your nose |url=https://www.reuters.com/article/us-genes-odor/stinky-its-not-his-sweat-its-your-nose-idUSN1522717720070916 |work=Reuters |date=16 September 2007 }}</ref>

There are two different genotypes that allow an individual to smell androstenone. The first genotype, which consists of two fully functional copies of the gene, is the RT/RT allele, and the second is the RT/WM allele.{{fact|date=April 2021}} The [[OR7D4]] receptor<ref name="Wysocki & Beauchamp 1984"/> has two non-synonymous single nucleotide polymorphisms,<ref>{{cite journal |last1=Keller |first1=Andreas |last2=Zhuang |first2=Hanyi |last3=Chi |first3=Qiuyi |last4=Vosshall |first4=Leslie B. |last5=Matsunami |first5=Hiroaki |title=Genetic variation in a human odorant receptor alters odour perception |journal=Nature |date=September 2007 |volume=449 |issue=7161 |pages=468–472 |doi=10.1038/nature06162 |pmid=17873857 |bibcode=2007Natur.449..468K |s2cid=4417235 |url=https://zenodo.org/record/896285 <!-- |lay-url=https://www.rockefeller.edu/news/2580-gene-determines-whether-male-body-odor-smells-pleasant/ --> }}</ref> which cause the gene to have two amino acid substitutions, which in turn cause the receptor to act differently. Those in possession of the two proper genes, (RT/RT) for [[OR7D4]] tend to describe the odor for the steroid as the odor of stale urine. Those with only one gene (RT/WM) typically described the odor as weak or were not able to detect it. They can also find the smell 'pleasant', 'sweet' or 'similar to vanilla'.<ref>{{cite news |last1=Swaminathan |first1=Nikhil |title=The Scent of a Man |url=https://www.scientificamerican.com/blog/post/the-scent-of-a-man/ |work=Scientific American |date=18 September 2007 }}</ref>

In small amounts, the odor is hardly detectable by most people. This may be due to a [[Polymorphism (biology)|polymorphism]] in the receptor gene that codes for the androstenone receptor.<ref>{{cite journal |last1=Lundstrom |first1=J. N. |last2=Seven |first2=S. |last3=Olsson |first3=M. J. |last4=Schaal |first4=B. |last5=Hummel |first5=T. |title=Olfactory Event-Related Potentials Reflect Individual Differences in Odor Valence Perception |journal=Chemical Senses |date=1 October 2006 |volume=31 |issue=8 |pages=705–711 |doi=10.1093/chemse/bjl012 |pmid=16844768 }}</ref> However, the ability to detect the odor varies greatly. It has been shown that the odor can be detected by people down to levels of 0.2 parts per billion to 0.2 parts in 100 million.<ref>{{cite news |last1=Birchall |first1=Annabelle |title=A whiff of happiness: Can smelling a molecule contained in human sweat ease anxiety and stress? Some scientists think so, and argue that 'osmotherapy' may also help people to slim or stop smoking |url=https://www.newscientist.com/article/mg12717314-700/ |work=New Scientist |date=25 August 1990 }}</ref> Several groups report, however, that some individuals who initially cannot smell androstenone can learn to smell it by repeated exposures to it.<ref>{{cite news |last1=Graham |first1=Sarah |title=Nostrils Share Information for Recognizing Scents |url=https://www.scientificamerican.com/article/nostrils-share-informatio/ |work=Scientific American |date=23 October 2002 }}</ref>

===Detectability as a pheromone===
In humans, androstenone also has been suggested to be a [[pheromone]]; however, there is little scientific data to support this claim.<ref>{{cite book |last1=Kirk-Smith |first1=M.D. |last2=Booth |first2=D.A. |year=1980 |chapter=Effect of androstenone on choice of location in others' presence |pages=397–400 |editor1-last=van der Starre |editor1-first=H |title=Proceedings of the 7th International Symposium on Olfaction and Taste (ISOT VII) and of the 4th Congress of the European Chemoreception Research Organization (ECRO IV): joint meeting held at 'de Leeuwenhorst' Congress Centre, Noordwijkerhout, the Netherlands, 22nd-25th July, 1980 |publisher=IRL Press |isbn=978-0-904147-20-9 |oclc=63367504 }}</ref>{{Better source needed|reason=Outdated research from 1980 (!) contradicted by many newer findings|date=February 2023}} The [[vomeronasal organ]] is an auxiliary olfactory sense organ responsible for the detection of pheromones as more than just an odor. Most adult humans possess something resembling this organ, but there is no active function. Humans lack the sensory cells that exist in other mammals needed to detect pheromones beyond a smell.{{Clarification needed|reason=See talk page and invisible comment|date=February 2023}}{{Dubious|Human pheromone detection|date=February 2023}} Humans also lack the genetic ability to produce these sensory cells actively.{{Citation needed|reason=the citation was of a entry in New scientist which is a non-peer-reviewed popular science magazine|date=March 2014}}

There is also a specific [[anosmia]] to the odor in some humans; they are unable to smell specific odors, but have, otherwise, a normal sense of smell. However, this should, by no means, be regarded as indicative for being labeled as a pheromone, as it is true of over 80 olfactory compounds.<ref>{{cite journal |last1=Araneda |first1=Ricardo C. |last2=Firestein |first2=Stuart |title=The scents of androstenone in humans |journal=The Journal of Physiology |date=1 January 2004 |volume=554 |issue=1 |pages=1 |doi=10.1113/jphysiol.2003.057075 |pmid=14678483 |pmc=1664751 }}</ref>

To other animals, the smell of androstenone can act as a social sign of dominance and can be a way of attracting a mate.{{Citation needed|date=September 2023}}{{Dubious|date=September 2023}}

===Commercial use===
Some commercially available products are advertised using claims that they contain human sexual pheromones, including androstenone, and that they can act as an [[aphrodisiac]].{{fact|date=November 2023}}

==See also==
* [[List of neurosteroids#Pheromones and pherines|List of neurosteroids § Pheromones and pherines]]

==References==
{{Reflist}}

{{Pheromones and pherines}}
{{Steroid hormones}}

[[Category:Androstanes]]
[[Category:Human pheromones]]
[[Category:Mammalian pheromones]]
[[Category:Neurosteroids]]