View source for Chemistry:Anethole

{{chembox
| Watchedfields  = changed
| verifiedrevid  = 443390450
| Name           = 
| ImageFile      = Anethole acsv.svg
| ImageSize      = 220
| ImageAlt       = Skeletal formula of anethole
| ImageFile1     = Anethole-3D-balls.png
| ImageSize1     = 220
| ImageAlt1      = Ball-and-stick model of the anethole molecule
| PIN            = 1-Methoxy-4-[(''E'')-prop-1-enyl]benzene<ref>{{cite web | url=https://pubchem.ncbi.nlm.nih.gov/compound/637563#section=IUPAC-Name&fullscreen=true | title=Anethole }}</ref>
| SystematicName = 
| OtherNames     = (''E'')-1-Methoxy-4-(prop-1-en-1-yl)benzene<br />(''E'')-1-Methoxy-4-(1-propenyl)benzene<br />''para''-Methoxyphenylpropene<br />''p''-Propenylanisole<br />Isoestragole<br />''trans''-1-Methoxy-4-(prop-1-enyl)benzene
| IUPACName      = 
| Section1       = {{Chembox Identifiers
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = Q3JEK5DO4K
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D02377
| InChI = 1/C10H12O/c1-3-4-9-5-7-10(11-2)8-6-9/h3-8H,1-2H3/b4-3+
| InChIKey = RUVINXPYWBROJD-ONEGZZNKBR
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 452630
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C10H12O/c1-3-4-9-5-7-10(11-2)8-6-9/h3-8H,1-2H3/b4-3+
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = RUVINXPYWBROJD-ONEGZZNKSA-N
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo1 = 4180-23-8
| CASNo1_Comment = ''E'' isomer
| CASNo2 = 104-46-1
| CASNo2_Comment = Unspecified stereochemistry (most commonly used CAS, implicitly ''E'')
| CASNo3 = 25679-28-1
| CASNo3_Comment = ''Z'' isomer
| PubChem = 637563
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 35616
| SMILES = O(c1ccc(\C=C\C)cc1)C
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID =553166
  }}
| Section2       = {{Chembox Properties
| C =10|H=12|O=1
| MolarMassUnit = g/mol
| Appearance = 
| Density = 0.998&nbsp;g/cm<sup>3</sup>
| MeltingPtC = 20 to 21
| BoilingPtC = 234
| BoilingPt_notes = <br/>{{cvt|81|°C|°F K|abbr=on}} at 2&nbsp;mmHg
| Solubility = 
| MagSus = {{val|-9.60e-5|u=cm<sup>3</sup>/mol}}
  }}
| Section3       = {{Chembox Hazards
| ExternalSDS = [https://web.archive.org/web/20010905233920/http://physchem.ox.ac.uk/MSDS/AN/anethole.html External MSDS]
| FlashPt = 
| AutoignitionPt = 
  }}
| Section4       = 
| Section5       = 
| Section6       = 
| Section8       = {{Chembox Related
| OtherCompounds = [[Chemistry:Anisole|anisole]]<br>[[Chemistry:Estragole|estragole]]}}
}}

'''Anethole''' (also known as '''anise camphor''')<ref>{{cite web|url=https://www.collinsdictionary.com/us/dictionary/english/anise-camphor|title=Anise camphor definition and meaning &#124; Collins English Dictionary}}</ref> is an [[Chemistry:Organic compound|organic compound]] that is widely used as a [[Chemistry:Flavoring|flavoring]] substance. It is a derivative of the aromatic compound [[Chemistry:Allylbenzene|allylbenzene]] and occurs widely in plants in [[Chemistry:Essential oil|essential oil]]s. It is in the class of [[Chemistry:Phenylpropanoid|phenylpropanoid]] organic compounds. It contributes a large component of the odor and flavor of [[Biology:Anise|anise]] and [[Biology:Fennel|fennel]] (both in the botanical family [[Biology:Apiaceae|Apiaceae]]), [[Biology:Syzygium anisatum|anise myrtle]] ([[Biology:Myrtaceae|Myrtaceae]]), [[Biology:Liquorice|liquorice]] ([[Biology:Fabaceae|Fabaceae]]), magnolia blossoms, and star anise ([[Biology:Schisandraceae|Schisandraceae]]). Closely related to anethole is its [[Chemistry:Isomer|isomer]] [[Chemistry:Estragole|estragole]], which is abundant in [[Biology:Tarragon|tarragon]] ([[Biology:Asteraceae|Asteraceae]]) and [[Biology:Basil|basil]] ([[Biology:Lamiaceae|Lamiaceae]]), and has a flavor reminiscent of anise. It is a colorless, fragrant, mildly volatile liquid.{{clarify|reason=does this statement refer to anethole or estragole?|date=October 2023}}<ref name=Ullmann>{{Ullmann|first1=Karl-Georg|last1=Fahlbusch|first2=Franz-Josef|last2=Hammerschmidt|first3=Johannes|last3=Panten|first4=Wilhelm|last4=Pickenhagen|first5=Dietmar|last5=Schatkowski|first6=Kurt|last6=Bauer|first7=Dorothea|last7=Garbe|first8=Horst|last8=Surburg|title=Flavors and Fragrances|doi=10.1002/14356007.a11_141}}</ref> Anethole is only slightly soluble in [[Chemistry:Water|water]] but exhibits high solubility in [[Chemistry:Ethanol|ethanol]]. This trait causes certain anise-flavored liqueurs to become opaque when diluted with water; this is called the [[Biology:Ouzo effect|ouzo effect]].

== Structure and production ==
Anethole is an aromatic, [[Chemistry:Saturated and unsaturated compounds|unsaturated]] [[Chemistry:Ether|ether]] related to [[Chemistry:Monolignol|lignols]]. It exists as both ''cis''–''trans'' isomers (see also ''E''–''Z'' notation), involving the double bond outside the ring. The more abundant isomer, and the one preferred for use, is the ''trans'' or ''E'' isomer.<ref name="chemistry-europe.onlinelibrary.wiley.com">{{cite journal|last1=Zhang|first1=Hongwei|last2=Lim|first2=Candy Li-Fen|last3=Zaki|first3=Muhammad|last4=Jaenicke|first4=Stephan|last5=Chuah|first5=Gaik Khuan|date=2018|title=A Dual-Functional Catalyst for Cascade Meerwein–Pondorf–Verley Reduction and Dehydration of 4′-Methoxypropiophenone to Anethole|url=https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cssc.201801340|journal=ChemSusChem|language=en|volume=11|issue=17|pages=3007–3017|doi=10.1002/cssc.201801340|pmid=29927044|s2cid=49342669|issn=1864-564X}}</ref>

Like related compounds, anethole is poorly soluble in water. Historically, this property was used to detect adulteration in samples.<ref>{{cite journal|title=Essential oils|year=1920|volume=14|issue=17|pages=3753–3755|first=S.|last=Waldbott|journal=Chemical Abstracts|url=https://books.google.com/books?id=isq2AAAAIAAJ&pg=PA3753}}</ref>

Most anethole is obtained from [[Chemistry:Turpentine|turpentine]]-like extracts from trees.<ref name=Ullmann /><ref>{{cite patent|country=US|number=4902850|title=Purification of anethole by crystallization|inventor=Davis, Curry B.|gdate=1990-02-20}}</ref> Of only minor commercial significance, anethole can also be isolated from essential oils.<ref>{{cite book|title=Chopra's Indigenous Drugs of India|first1=R. N.|last1=Chopra|first2=I. C.|last2=Chopra|first3=K. L.|last3=Handa|first4=L. D.|last4=Kapur|publisher=Academic Publishers|year=1958|edition=2nd|pages=178–179|url=https://books.google.com/books?id=2HyC4-GJ50YC&pg=PA178|isbn=978-81-85086-80-4}}</ref><ref name="Ashurst">{{cite book|title=Food Flavorings|first=Philip R.|last=Ashurst|publisher=Springer|year=1999|page=460|url=https://books.google.com/books?id=hrWuqmtwJiEC&q=anethole|isbn=978-0-8342-1621-1}}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{cite journal|title=Liquid CO<sub>2</sub> Extraction and NMR Characterization of Anethole from Fennel Seed: A General Chemistry Laboratory|first1=B. R.|last1=Bodsgard|first2=N. R.|last2=Lien|first3=Q. T.|last3=Waulters|journal=Journal of Chemical Education|date=2016|volume=93|issue=2|pages=397–400|doi=10.1021/acs.jchemed.5b00689|bibcode=2016JChEd..93..397B}}</ref><!-- pages 11, 33, 34-->

{| class="wikitable"
|-
! Essential oil
! World production
! ''Trans''-anethole
|-
| Anise
| 8 tonnes (1999)
| 95%
|-
| Star anise
| 400 tonnes (1999), mostly from China
| 87%
|-
| Fennel
| 25 tonnes (1999), mostly from Spain
| 70%
|}

Currently Banwari Chemicals Pvt Ltd situated in Bhiwadi, Rajasthan, India is the leading manufacturer of anethole. It is prepared commercially from 4-methoxy[[Chemistry:Propiophenone|propiophenone]],<ref name="chemistry-europe.onlinelibrary.wiley.com"/><ref>{{cite journal|date=2021-08-01|title=Hydrophobicity and co-solvent effects on Meerwein-Ponndorf-Verley reduction/dehydration cascade reactions over Zr-zeolite catalysts|url=https://www.sciencedirect.com/science/article/abs/pii/S0021951721001962|journal=Journal of Catalysis|language=en|volume=400|pages=50–61|doi=10.1016/j.jcat.2021.05.011|issn=0021-9517|last1=Zhang|first1=Hongwei|last2=Quek|first2=Zhan Jiang|last3=Jaenicke|first3=Stephan|last4=Chuah|first4=Gaik-Khuan|s2cid=236342527}}</ref> which is prepared from [[Chemistry:Anisole|anisole]].<ref name=Ullmann />

== Uses ==
=== Flavoring ===
Anethole is distinctly sweet, measuring 13 times sweeter than [[Chemistry:Sugar|sugar]]. It is perceived as being pleasant to the taste even at higher concentrations. It is used in alcoholic drinks ouzo, rakı, [[Biology:Anisette|anisette]] and [[Biology:Absinthe|absinthe]], among others. It is also used in seasoning and confectionery applications, such as German Lebkuchen, oral hygiene products, and in small quantities in natural berry [[Chemistry:Flavoring|flavor]]s.<ref name="Ashurst" />

=== Precursor to other compounds ===
Because they [[Biology:Metabolism|metabolize]] anethole into several aromatic chemical compounds, some bacteria are candidates for use in commercial [[Biology:Bioconversion|bioconversion]] of anethole to more valuable materials.<ref name="pmid11805095" /> Bacterial strains capable of using trans-anethole as the sole carbon source include JYR-1 (''[[Biology:Pseudomonas putida|Pseudomonas putida]]'')<ref name="pmid16028980">{{cite journal|last1=Ryu|first1=J.|last2=Seo|first2=J.|last3=Lee|first3=Y.|last4=Lim|first4=Y.|last5=Ahn|first5=J. H.|last6=Hur|first6=H. G.|title=Identification of ''syn''- and ''anti''-anethole-2,3-epoxides in the metabolism of ''trans''-anethole by the newly isolated bacterium ''Pseudomonas putida'' JYR-1|journal=Journal of Agricultural and Food Chemistry|volume=53|issue=15|pages=5954–5958|date=2005|pmid=16028980|doi=10.1021/jf040445x}}</ref> and TA13 (''Arthrobacter aurescens'').<ref name="pmid11805095">{{cite journal|last1=Shimoni|first1=E|last2=Baasov|first2=T.|last3=Ravid|first3=U.|last4=Shoham|first4=Y.|title=The ''trans''-anethole degradation pathway in an ''Arthrobacter'' sp.|journal=Journal of Biological Chemistry|volume=277|issue=14|pages=11866–11872|year=2002|pmid=11805095|doi=10.1074/jbc.M109593200|doi-access=free}}</ref>

== Research ==
=== Antimicrobial and antifungal activity ===
Anethole has potent [[Biology:Antimicrobial|antimicrobial]] properties, against [[Biology:Bacteria|bacteria]], [[Biology:Yeast|yeast]]s, and [[Biology:Fungi|fungi]].<ref name="pmid11807977">{{cite journal|last1=De|first1=M.|last2=De|first2=A. K.|last3=Sen|first3=P.|last4=Banerjee|first4=A. B.|title=Antimicrobial properties of star anise (''Illicium verum'' Hook. f.)|journal=Phytotherapy Research|volume=16|issue=1|pages=94–95|date=2002|pmid=11807977|doi=10.1002/ptr.989|s2cid=27196549}}</ref> Reported antibacterial properties include both bacteriostatic and bactericidal action against ''[[Biology:Salmonella enterica|Salmonella enterica]]''<ref name="pmid11743758">{{cite journal|last1=Kubo|first1=I.|last2=Fujita|first2=K.|title=Naturally occurring anti-''Salmonella'' agents|journal=Journal of Agricultural and Food Chemistry|volume=49|issue=12|pages=5750–5754|date=2001|pmid=11743758|doi=10.1021/jf010728e}}</ref> but not when used against ''Salmonella'' via a [[Biology:Fumigation|fumigation]] method.<ref name="pmid11307877">{{cite journal|last1=Weissinger|first1=W. R.|last2=McWatters|first2=K. H.|last3=Beuchat|first3=L. R.|title    = Evaluation of volatile chemical treatments for lethality to ''Salmonella'' on alfalfa seeds and sprouts|journal=Journal of Food Protection|volume=64|issue=4|pages=442–450|date=April 2001|pmid=11307877|doi=10.4315/0362-028X-64.4.442|doi-access=free}}</ref> Antifungal activity includes increasing the effectiveness of some other [[Chemistry:Phytochemical|phytochemical]]s (such as [[Chemistry:Polygodial|polygodial]]) against ''[[Biology:Saccharomyces cerevisiae|Saccharomyces cerevisiae]]'' and ''[[Biology:Candida albicans|Candida albicans]]'';<ref name="pmid17078111">{{cite journal|last1=Fujita|first1=K.|last2=Fujita|first2=T.|last3=Kubo|first3=I.|title=Anethole, a potential antimicrobial synergist, converts a fungistatic dodecanol to a fungicidal agent|journal=Phytotherapy Research|volume=21|issue=1|pages=47–51|date=2007|pmid=17078111|doi=10.1002/ptr.2016|s2cid=9666596|doi-access=free}}</ref>

''[[In vitro]]'', anethole has antihelmintic action on eggs and larvae of the sheep gastrointestinal [[Biology:Nematode|nematode]] ''[[Biology:Haemonchus contortus|Haemonchus contortus]]''.<ref name="pmid17629623">{{cite journal|last1=Camurça-Vasconcelos|first1=A. L.|last2=Bevilaqua|first2=C. M.|last3=Morais|first3=S. M.|last4=Maciel|first4=M. V.|last5=Costa|first5=C. T.|last6=Macedo|first6=I. T.|last7=Oliveira|first7=L. M.|last8=Braga|first8=R. R.|last9=Silva|first9=R. A.|last10=Vieira|first10=L. S.|title=Anthelmintic activity of ''Croton zehntneri'' and ''Lippia sidoides'' essential oils|journal=Veterinary Parasitology|volume=148|issue=3–4|pages=288–294|year=2007|pmid=17629623|doi=10.1016/j.vetpar.2007.06.012}}</ref> Anethole also has nematicidal activity against the plant nematode ''[[Biology:Meloidogyne javanica|Meloidogyne javanica]]'' in vitro and in pots of cucumber seedlings.<ref name="pmid18944489">{{cite journal|last1=Oka|first1=Y.|last2=Nacar|first2=S.|last3=Putievsky|first3=E.|last4=Ravid|first4=U.|last5=Yaniv|first5=Z.|last6=Spiegel|first6=Y.|title=Nematicidal activity of essential oils and their components against the root-knot nematode|journal=Phytopathology|volume=90|issue=7|pages=710–715|date=2000|pmid=18944489|doi=10.1094/PHYTO.2000.90.7.710|doi-access=free}}</ref>

=== Insecticidal activity ===
Anethole also is a promising insecticide. Several essential oils consisting mostly of anethole have [[Biology:Insecticide|insecticidal]] action against [[Biology:Larva|larva]]e of the [[Biology:Mosquito|mosquito]] ''[[Biology:Ochlerotatus|Ochlerotatus]] caspius''<ref name="pmid17368893">{{cite journal|last1=Knio|first1=K. M.|last2=Usta|first2=J.|last3=Dagher|first3=S.|last4=Zournajian|first4=H.|last5=Kreydiyyeh|first5=S.|title=Larvicidal activity of essential oils extracted from commonly used herbs in Lebanon against the seaside mosquito, ''Ochlerotatus caspius''|journal=Bioresource Technology|volume=99|issue=4|pages=763–768|year=2008|pmid=17368893|doi=10.1016/j.biortech.2007.01.026|bibcode=2008BiTec..99..763K }}</ref> and ''[[Biology:Aedes aegypti|Aedes aegypti]]''.<ref name="pmid15237942">{{cite journal|last1=Cheng|first1=S. S.|last2=Liu|first2=J. Y.|last3=Tsai|first3=K. H.|last4=Chen|first4=W. J.|last5=Chang|first5=S. T.|title=Chemical composition and mosquito larvicidal activity of essential oils from leaves of different ''Cinnamomum osmophloeum'' provenances|journal=Journal of Agricultural and Food Chemistry|volume=52|issue=14|pages=4395–4400|date=2004|pmid=15237942|doi=10.1021/jf0497152}}</ref><ref name="pmid16646345">{{cite journal|last1=Morais|first1=S. M.|last2=Cavalcanti|first2=E. S.|last3=Bertini|first3=L. M.|last4=Oliveira|first4=C. L.|last5=Rodrigues|first5=J. R.|last6=Cardoso|first6=J. H.|title=Larvicidal activity of essential oils from Brazilian ''Croton'' species against ''Aedes aegypti'' L.|journal=Journal of the American Mosquito Control Association|volume=22|issue=1|pages=161–164|year=2006|pmid=16646345|doi=10.2987/8756-971X(2006)22[161:LAOEOF]2.0.CO;2|s2cid=33429927 }}</ref> In a similar manner, anethole itself is effective against the [[Biology:Fungus gnat|fungus gnat]] ''Lycoriella ingenua'' ([[Biology:Sciaridae|Sciaridae]])<ref name="pmid16786497">{{cite journal|last1=Park|first1=I. K.|last2=Choi|first2=K. S.|last3=Kim|first3=D. H.|last4=Choi|first4=I. H.|last5=Kim|first5=L. S.|last6=Bak|first6=W. C.|last7=Choi|first7=J. W.|last8=Shin|first8=S. C.|title=Fumigant activity of plant essential oils and components from horseradish (''Armoracia rusticana''), anise (''Pimpinella anisum'') and garlic (''Allium sativum'') oils against ''Lycoriella ingenua'' (Diptera: Sciaridae)|journal=Pest Management Science|volume=62|issue=8|pages=723–728|date=2006|pmid=16786497|doi=10.1002/ps.1228}}</ref> and the mold mite ''Tyrophagus putrescentiae''.<ref name="pmid15954709">{{cite journal|last1=Lee|first1=H. S.|title=Food protective effect of acaricidal components isolated from anise seeds against the stored food mite, ''Tyrophagus putrescentiae'' (Schrank)|journal=Journal of Food Protection|volume=68|issue=6|pages=1208–1210|date=2005|pmid=15954709|doi=10.4315/0362-028X-68.6.1208|doi-access=free}}</ref> Against the mite, anethole is a slightly more effective [[Biology:Pesticide|pesticide]] than [[Chemistry:DEET|DEET]], but anisaldehyde, a related natural compound that occurs with anethole in many essential oils, is 14 times more effective.<ref name="pmid15954709" /> The insecticidal action of anethole is greater as a [[Biology:Fumigation|fumigant]] than as a contact agent. ''trans''-Anethole is highly effective as a fumigant against the [[Biology:Cockroach|cockroach]] ''Blattella germanica''<ref name="pmid11852640">{{cite journal|last1=Chang|first1=K. S.|last2=Ahn|first2=Y. J.|title=Fumigant activity of (''E'')-anethole identified in ''Illicium verum'' fruit against ''Blattella germanica''|journal=Pest Management Science|volume=58|issue=2|pages=161–166|date=2002|pmid=11852640|doi=10.1002/ps.435}}</ref> and against adults of the [[Biology:Weevil|weevil]]s ''Sitophilus oryzae'', ''[[Biology:Callosobruchus chinensis|Callosobruchus chinensis]]'' and [[Biology:Beetle|beetle]] ''[[Biology:Lasioderma serricorne|Lasioderma serricorne]]''.<ref name="pmid11455661">{{cite journal|last1=Kim|first1=D. H.|last2=Ahn|first2=Y. J.|title=Contact and fumigant activities of constituents of ''Foeniculum vulgare'' fruit against three coleopteran stored-product insects|journal=Pest Management Science|volume=57|issue=3|pages=301–306|date=2001|pmid=11455661|doi=10.1002/ps.274}}</ref>

As well as an insect pesticide, anethole is an effective [[Chemistry:Insect repellent|insect repellent]] against mosquitos.<ref name="pmid12963152">{{cite journal|last1=Padilha de Paula|first1=J.|last2=Gomes-Carneiro|first2=M. R.|last3=Paumgartten|first3=F. J.|title=Chemical composition, toxicity and mosquito repellency of ''Ocimum selloi'' oil|journal=Journal of Ethnopharmacology|volume=88|issue=2–3|pages=253–260|year=2003|pmid=12963152|doi=10.1016/s0378-8741(03)00233-2}}</ref>

=== Ouzo effect ===
[[File:Preparing absinthe.jpg|thumb|Diluting absinthe with water produces a spontaneous microemulsion (ouzo effect)]]
Anethole is responsible for the "[[Biology:Ouzo effect|ouzo effect]]" (also "louche effect"), the spontaneous formation of a [[Chemistry:Microemulsion|microemulsion]]<ref name="Sitnikova+2005">{{cite journal|last1=Sitnikova|first1=Natalia L.|first2=Rudolf|last2=Sprik|first3=Gerard|last3=Wegdam|first4=Erika|last4=Eiser|year=2005|title=Spontaneously formed ''trans''-anethol/water/alcohol emulsions: Mechanism of formation and stability|journal=Langmuir|volume=21|issue=16|pages=7083–7089|doi=10.1021/la046816l|url=http://www.science.uva.nl/~sprik/personal/pdf/05/la046816l.pdf|access-date=2009-03-15|pmid=16042427|archive-url=https://web.archive.org/web/20090318153610/http://www.science.uva.nl/~sprik/personal/pdf/05/la046816l.pdf|archive-date=2009-03-18|url-status=dead}}</ref><ref>{{cite journal|title=The "Ouzo effect": Following the spontaneous emulsification of ''trans''-anethole in water by NMR|journal=Comptes Rendus Chimie|volume=11|issue=4–5|date=2008|pages=493–498|first1=David|last1=Carteau|first2=Dario|last2=Bassani|first3=Isabelle|last3=Pianet|doi=10.1016/j.crci.2007.11.003|url=https://comptes-rendus.academie-sciences.fr/chimie/articles/10.1016/j.crci.2007.11.003/ }}</ref> that gives many alcoholic beverages containing anethole and water their cloudy appearance.<ref name="Sanchez-Dominguez Rodriguez-Abreu 2016 p. 369">{{cite book|last1=Sánchez Domínguez|first1=M.|last2=Rodríguez Abreu|first2=C.|title=Nanocolloids: A Meeting Point for Scientists and Technologists|publisher=Elsevier Science|year=2016|isbn=978-0-12-801758-6|url=https://books.google.com/books?id=ReXIBAAAQBAJ&pg=PA369|access-date=2018-08-02|page=369|quote= O/W and W/O nano-emulsions can also be formed without a surfactant by self-emulsification, using the so-called Ouzo effect. The major components of Ouzo (a Greek drink) are ''trans''-anethole, ethanol, and water. Anethole is almost insoluble ...}}</ref> Such a spontaneous microemulsion has many potential commercial applications in the food and pharmaceutical industries.<ref name="pmid17229398">{{cite journal|last1=Spernath|first1=A.|last2=Aserin|first2=A.|title=Microemulsions as carriers for drugs and nutraceuticals|journal=Advances in Colloid and Interface Science|volume=128–130|pages=47–64|year=2006|pmid=17229398|doi=10.1016/j.cis.2006.11.016}}</ref>

=== Precursor to illicit drugs ===
Anethole is an inexpensive chemical precursor for paramethoxyamphetamine (PMA),<ref name="pmid12742705">{{cite journal|last1=Waumans|first1=D.|last2=Bruneel|first2=N.|last3=Tytgat|first3=J.|title=Anise oil as ''para''-methoxyamphetamine (PMA) precursor|journal=Forensic Science International|volume=133|issue=1–2|pages=159–170|year=2003|pmid=12742705|doi=10.1016/S0379-0738(03)00063-X}}</ref> and is used in its clandestine manufacture.<ref name="pmid15240033">{{cite journal|last1=Waumans|first1=D.|last2=Hermans|first2=B.|last3=Bruneel|first3=N.|last4=Tytgat|first4=J.|title=A neolignan-type impurity arising from the peracid oxidation reaction of anethole in the surreptitious synthesis of 4-methoxyamphetamine (PMA)|journal=Forensic Science International|volume=143|issue=2–3|pages=133–139|year=2004|pmid=15240033|doi=10.1016/j.forsciint.2004.02.033}}</ref> Anethole is present in the essential oil from [[Biology:Guarana|guarana]], which has psychoactive effects typically attributed to its caffeine content. The absence of PMA or any other known psychoactive derivative of anethole in human urine after ingestion of guarana leads to the conclusion that any psychoactive effect of guarana is not due to aminated anethole metabolites.<ref name="pmid8765992">{{cite journal|last1=Benoni|first1=H.|last2=Dallakian|first2=P.|last3=Taraz|first3=K.|title=Studies on the essential oil from guarana|journal=Zeitschrift für Lebensmittel-Untersuchung und -Forschung|volume=203|issue=1|pages=95–98|year=1996|pmid=8765992|doi=10.1007/BF01267777|s2cid=45636969}}</ref>

Anethole is also present in [[Biology:Absinthe|absinthe]], a [[Chemistry:Liquor|liquor]] with a reputation for psychoactive effects; these effects, however, are attributed to [[Chemistry:Ethanol|ethanol]].<ref name="pmid18429531">{{cite journal|last=Lachenmeier|first=D. W.|title=Thujon-Wirkungen von Absinth sind nur eine Legende—Toxikologie entlarvt Alkohol als eigentliche Absinthismus-Ursache|trans-title=Thujone-attributable effects of absinthe are only an urban legend—toxicology uncovers alcohol as real cause of absinthism|language=de|journal=Medizinische Monatsschrift für Pharmazeuten|volume=31|issue=3|pages=101–106|date=2008|pmid=18429531}}</ref> (See also [[Chemistry:Thujone|thujone]], anethole dithione (ADT), and [[Chemistry:Anethole trithione|anethole trithione]] (ATT).)

=== Estrogen and prolactin ===
Anethole has [[Biology:Estrogen|estrogen]]ic activity.<ref name="Jordan1986">{{cite book|first=Virgil Craig|last=Jordan|title=Estrogen/Antiestrogen Action and Breast Cancer Therapy|url=https://books.google.com/books?id=7WmLZfGXST0C&pg=PA21|year=1986|publisher=University of Wisconsin Press|isbn=978-0-299-10480-1|pages=21–22}}</ref><ref>{{cite journal |last1=Howes |first1=M.-J. R. |last2=Houghton |first2=P. J. |last3=Barlow |first3=D. J. |last4=Pocock |first4=V. J. |last5=Milligan |first5=S. R. |date=November 2002 |title=Assessment of estrogenic activity in some common essential oil constituents |journal=The Journal of Pharmacy and Pharmacology |volume=54 |issue=11 |pages=1521–1528 |doi=10.1211/002235702216 |issn=0022-3573 |pmid=12495555|s2cid=28650422 |doi-access=free }}</ref><ref>{{cite journal |last=Albert-Puleo |first=M. |date=December 1980 |title=Fennel and anise as estrogenic agents |url=https://pubmed.ncbi.nlm.nih.gov/6999244/ |journal=Journal of Ethnopharmacology |volume=2 |issue=4 |pages=337–344 |doi=10.1016/s0378-8741(80)81015-4 |issn=0378-8741 |pmid=6999244}}</ref> It has been found to significantly increase uterine weight in immature female rats.<ref name="TisserandYoung2013">{{cite book|first1=Robert|last1=Tisserand|first2=Rodney|last2=Young|title=Essential Oil Safety: A Guide for Health Care Professionals|url=https://books.google.com/books?id=DbEKAQAAQBAJ&pg=PA150|date=2013|publisher=Elsevier Health Sciences|isbn=978-0-7020-5434-1|page=150}}</ref>

Fennel, which contains anethole, has been found to have a [[Unsolved:Galactagogue|galactagogue]] effect in animals. Anethole bears a structural resemblance to [[Biology:Catecholamine|catecholamine]]s like [[Biology:Dopamine|dopamine]] and may displace dopamine from its receptors and thereby disinhibit [[Biology:Prolactin|prolactin]] secretion, which in turn may be responsible for the galactagogue effects.<ref name="BoneMills2013">{{cite book|first1=Kerry|last1=Bone|first2=Simon Y.|last2=Mills|title=Principles and Practice of Phytotherapy|series=Modern Herbal Medicine|volume=2|url=https://books.google.com/books?id=5V1QlqHazcwC&pg=PA559|year=2013|publisher=Elsevier Health Sciences|isbn=978-0-443-06992-5|page=559}}</ref>

== Safety ==
In the USA, anethole is [[Chemistry:Generally recognized as safe|generally recognized as safe]] (GRAS). After a hiatus due to safety concerns, anethole was reaffirmed by [[Organization:Flavor and Extract Manufacturers Association|Flavor and Extract Manufacturers Association]] (FEMA) as GRAS.<ref name="pmid10496381">{{cite journal|last1=Newberne|first1=P.|last2=Smith|first2=R. L.|last3=Doull|first3=J.|last4=Goodman|first4=J. I.|last5=Munro|first5=I. C.|last6=Portoghese|first6=P. S.|last7=Wagner|first7=B. M.|last8=Weil|first8=C. S.|last9=Woods|first9=L. A.|last10=Adams|first10=T. B.|last11=Lucas|first11=C. D.|last12=Ford|first12=R. A.|title=The FEMA GRAS assessment of ''trans''-anethole used as a flavouring substance. Flavour and Extract Manufacturers' Association|journal=Food and Chemical Toxicology|volume=37|issue=7|pages=789–811|year=1999|pmid=10496381|doi=10.1016/S0278-6915(99)00037-X}}</ref> The concerns related to liver toxicity and possible carcinogenic activity reported in [[Biology:Rat|rat]]s.<ref name="pmid2467866">{{cite journal|last1=Newberne|first1=P. M.|last2=Carlton|first2=W. W.|last3=Brown|first3=W. R.|title=Histopathological evaluation of proliferative liver lesions in rats fed trans-anethole in chronic studies|journal=Food and Chemical Toxicology|volume=27|issue=1|pages=21–26|year=1989|pmid=2467866|doi=10.1016/0278-6915(89)90087-2}}</ref> Anethole is associated with a slight increase in [[Medicine:Liver cancer|liver cancer]] in rats,<ref name="pmid2467866" /> although the evidence is scant and generally regarded as evidence that anethole is ''not'' a [[Biology:Carcinogen|carcinogen]].<ref name="pmid2467866" /><ref name="pmid12151622">{{cite journal|last=Waddell|first=W. J.|title=Thresholds of carcinogenicity of flavors|journal=Toxicological Sciences|volume=68|issue=2|pages=275–279|year=2002|pmid=12151622|doi=10.1093/toxsci/68.2.275|doi-access=free}}</ref> An evaluation of anethole by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) found its notable [[Biology:Pharmacology|pharmacologic]] properties to be reduction in motor activity, lowering of body temperature, and [[Chemistry:Hypnotic|hypnotic]], [[Biology:Analgesic|analgesic]], and [[Chemistry:Anticonvulsant|anticonvulsant]] effects.<ref name="JECFA466">{{cite web|title=''trans''-Anethole|publisher=International Program on Chemical Safety (IPCS)|author=Joint FAO/WHO Expert Committee on Food Additives|issue=466|series=WHO Food Additives Series|volume=14|url=http://www.inchem.org/documents/jecfa/jecmono/v14je02.htm}}</ref> A subsequent evaluation by JECFA found some reason for concern regarding carcinogenicity, but there is currently insufficient data to support this.<ref name="JECFA717">{{cite web|title=''trans''-Anethole|publisher=International Program on Chemical Safety (IPCS)|author=Joint FAO/WHO Expert Committee on Food Additives|year=1998|issue=717|series=WHO Food Additives Series|volume=28|url=http://www.inchem.org/documents/jecfa/jecmono/v28je10.htm}}</ref> At this time, the JECFA summary of these evaluations is that anethole has "no safety concern at current levels of intake when used as a flavoring agent".<ref name="JECeval">{{cite web|title=Summary of Evaluations Performed by the Joint FAO/WHO Expert Committee on Food Additives: ''trans''-Anethole|publisher=International Program on Chemical Safety (IPCS)|date=2001-11-12|url=http://www.inchem.org/documents/jecfa/jeceval/jec_137.htm|access-date=2009-03-10|archive-url=https://web.archive.org/web/20090311035152/http://www.inchem.org/documents/jecfa/jeceval/jec_137.htm|archive-date=2009-03-11|url-status=live}}</ref>

In large quantities, anethole is slightly toxic and may act as an irritant.<ref>{{cite web|title=Safety data for anethole|publisher=Physical & Theoretical Chemistry Laboratory Safety, Oxford University|url=http://msds.chem.ox.ac.uk/AN/anethole.html|access-date=2009-03-10|archive-url=https://web.archive.org/web/20080615174611/http://msds.chem.ox.ac.uk/AN/anethole.html|archive-date=2008-06-15|url-status=dead}}</ref> <!-- It can stimulate hepatic regeneration in rats, and can also produce spasmolytic activity in high doses.{{Citation needed|date=March 2009}} -->

== History ==
That an oil could be extracted from anise and fennel had been known since the [[Philosophy:Renaissance|Renaissance]] by the German alchemist Hieronymus Brunschwig ({{circa|1450|1512}}), the German botanist Adam Lonicer (1528–1586), and the German physician Valerius Cordus (1515–1544), among others.<ref name="semmler">See:
* {{cite book|last=Semmler|first=F. W.|title=Die ätherischen Öle nach ihren chemischen Bestandteilen unter Berücksichtigung der geschichtlichen Entwicklung|trans-title=The volatile oils according to their chemical components with regard to their historical development|language=de|location=Leipzig|publisher=Veit & Co.|date=1907|volume=4|url=https://books.google.com/books?id=JlA3AQAAMAAJ&pg=PA76|page=76}}
* {{cite book|last=Lippmann|first=Edmund Oskar von|title=Zeittafeln zur Geschichte der Organischen Chemie|trans-title=Timeline of the history of organic chemistry|language=de|location=Berlin|publisher=Springer-Verlag|date=1921|chapter-url=https://books.google.com/books?id=LDyHBwAAQBAJ&pg=PA1|chapter=§&nbsp;339. Anethol|page=1|isbn=9783662246665}}
* {{cite book|first1=Eduard|last1=Gildemeister|first2=Friedrich|last2=Hoffmann|translator-first=Edward|translator-last=Kremers|title=The Volatile Oils|location=Milwaukee, Wisconsin|publisher=Review Publishing Co.|date=1900|chapter-url=https://books.google.com/books?id=EAdKAAAAMAAJ&pg=PA563|chapter=§&nbsp;307. Oil of anise|pages=s558–s563}}</ref> Anethole was first investigated chemically by the Swiss chemist [[Biography:Nicolas-Théodore de Saussure|Nicolas-Théodore de Saussure]] in 1820.<ref>{{cite journal|first=N.-T.|last=De Saussure|date=1820|url=https://babel.hathitrust.org/cgi/pt?id=nyp.33433062741594;view=1up;seq=265|title=Observations sur la combinaison de l'essence de citron avec l'acide muriatique, et sur quelques substances huileuses|trans-title=Observations on the combination of lemon essence with muriatic acid, and on several oily substances|language=fr|journal=Annales de Chimie et de Physique |series=Série 2|volume=13|pages=259–284}} See especially pp. 280–284.</ref> In 1832, the French chemist Jean Baptiste Dumas determined that the crystallizable components of anise oil and fennel oil were identical, and he determined anethole's empirical formula.<ref>See:
* {{cite journal|last=Dumas|first=J.|year=1832|url=https://babel.hathitrust.org/cgi/pt?id=hvd.hx3dwm;view=1up;seq=235|title=Mémoire sur les substances végétales qui se rapprochent du camphre, et sur quelques huiles essentielles|trans-title=Memoir on plant substances that resemble camphor, and on several essential oils|language=fr|journal=Annales de Chimie et de Physique |series=Série 2 |volume=50|pages=225–240}} On p. 234, Dumas provides an [[Chemistry:Empirical formula|empirical formula]] C<sub>10</sub>H<sub>6</sub>O<sub>{{sfrac|1|2}}</sub> for anethol. If the subscripts are doubled and if the subscript for carbon is then halved (because Dumas, like many of his contemporaries, used the wrong [[Physics:Atomic mass|atomic mass]] for carbon, 6 instead of 12), then Dumas' empirical formula is correct.
* Dumas' finding that the crystallizable components of anise oil and fennel oil were identical was confirmed in 1833 by the team of Rodolphe Blanchet (1807–1864) and Ernst Sell (1808–1854). See: {{cite journal|last1=Blanchet|first1=Sell|date=1833|url=https://babel.hathitrust.org/cgi/pt?id=uva.x002457885;view=1up;seq=649|title=Ueber<!--sic--> die Zusammensetzung einiger organischer Substanzen|trans-title=On the composition of some organic substances|language=de|journal=Annalen der Pharmacie|volume=6|issue=3|pages=259–313|doi=10.1002/jlac.18330060304}} See especially pp. 287–288.
* Dumas' empirical formula for anethole was confirmed in 1841 by the French chemist Auguste Cahours. See: {{cite journal|last=Cahours|first=A. A. T.|date=1841|url=https://babel.hathitrust.org/cgi/pt?id=uva.x002489035;view=1up;seq=278|title=Sur les essences de fenouil, de badiane et d'anis|trans-title=On the essential oils of fennel, star anise, and anise|language=fr|journal=Annales de Chimie et de Physique |series=Série 3|volume=2|pages=274–308}} See pp. 278–279. Note that the subscripts of Cahours' empirical formula (C<sub>40</sub>H<sub>24</sub>O<sub>2</sub>) must be divided by 2 and then the subscript for carbon must be divided again by 2 (because, like many chemists of his time, Cahours used the wrong atomic mass for carbon, 6 instead of 12). If these changes are made, the resulting empirical formula is correct.</ref> In 1845, the French chemist Charles Gerhardt coined the term ''anethol'' – from the Latin ''anethum'' (anise) + ''oleum'' (oil) – for the fundamental compound from which a family of related compounds was derived.<ref>{{cite journal|last=Gerhardt|first=Charles|date=1845|url=https://babel.hathitrust.org/cgi/pt?id=njp.32101076785581;view=1up;seq=279|title=Ueber die Identität des Dragonöls und des Anisöls|trans-title=On the identity of tarragon oil and anise oil|language=de|journal=Journal für praktische Chemie|volume=36|pages=267–276|doi=10.1002/prac.18450360159 |quote=Ich werde keinen neuen Namen für jede einzelne Art der folgenden physisch verschiedenen Arten annehmen. In meinem Werke bezeichne ich sie als Varietäten der Gattung „Anethol“.|trans-quote=I will adopt no new name for any individual species of the following physically different species. In my work, I designate them as varieties of the genus ''anethol''.}}</ref> Although the German chemist Emil Erlenmeyer proposed the correct molecular structure for anethole in 1866,<ref>{{cite journal|last=Erlenmeyer|first=Emil|date=1866|url=https://books.google.com/books?id=6sEwAAAAYAAJ&pg=PA472|title=Ueber die Constitution des Anisols (Anethols)|trans-title=On the constitution of anisol (anethol)|language=de|journal=Zeitschrift für Chemie |series=2nd Series|volume=2|pages=472–474}}</ref> it was not until 1872, that the structure was accepted as correct.<ref name="semmler"/>

== See also ==
* List of liqueurs § Anise-flavored liqueurs
* [[Chemistry:Anol|Anol]]
* [[Chemistry:Chavicol|Chavicol]]
* [[Chemistry:Dianethole|Dianethole]]
* [[Chemistry:Fenchone|Fenchone]]
* [[Chemistry:Pseudoisoeugenol|Pseudoisoeugenol]]
* [[Chemistry:Safrole|Safrole]]

==References==
{{reflist|30em}}

==External links==

{{Phenylpropene}}
{{Estrogenics}}

[[Category:Flavors]]
[[Category:Sugar substitutes]]
[[Category:Essential oils]]
[[Category:Phenylpropenes]]
[[Category:Estrogens]]

{{Sourceattribution|Anethole}}