anethole

Anethole is an aromatic, unsaturated ether related to 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.{{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|bibcode=2018ChSCh..11.3007Z |s2cid=49342669|issn=1864-564X|url-access=subscription}}

Like related compounds, anethole is poorly soluble in water. Historically, this property was used to detect adulteration in samples.{{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}}

Most anethole is obtained from turpentine-like extracts from trees.{{cite patent|country=US|number=4902850|title=Purification of anethole by crystallization|inventor=Davis, Curry B.|gdate=1990-02-20}} Of only minor commercial significance, anethole can also be isolated from essential oils.{{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}}{{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 }}{{cite journal|title=Liquid CO₂ 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}}

Currently Banwari Chemicals Pvt Ltd situated in Bhiwadi, Rajasthan, India is the leading manufacturer of anethole. It is prepared commercially from 4-methoxypropiophenone,{{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|url-access=subscription}} which is prepared from anisole.

Anethole is distinctly sweet, measuring 13 times sweeter than sugar. It is perceived as being pleasant to the taste by many even at higher concentrations. It is used in alcoholic drinks ouzo, rakı, anisette and 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 flavors.

Because they metabolize anethole into several aromatic chemical compounds, some bacteria are candidates for use in commercial bioconversion of anethole to more valuable materials. Bacterial strains capable of using trans-anethole as the sole carbon source include JYR-1 (Pseudomonas putida){{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|bibcode=2005JAFC...53.5954R }} and TA13 (Arthrobacter aurescens).{{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}}

Anethole has potent antimicrobial properties, against bacteria, yeasts, and fungi.{{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}} Reported antibacterial properties include both bacteriostatic and bactericidal action against Salmonella enterica{{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|bibcode=2001JAFC...49.5750K }} but not when used against Salmonella via a fumigation method.{{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}} Antifungal activity includes increasing the effectiveness of some other phytochemicals (such as polygodial) against Saccharomyces cerevisiae and Candida albicans;{{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}}

In vitro, anethole has antihelmintic action on eggs and larvae of the sheep gastrointestinal nematode Haemonchus contortus.{{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}} Anethole also has nematicidal activity against the plant nematode Meloidogyne javanica in vitro and in pots of cucumber seedlings.{{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|bibcode=2000PhPat..90..710O }}

Anethole also is a promising insecticide. Several essential oils consisting mostly of anethole have insecticidal action against larvae of the mosquito Ochlerotatus caspius{{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 }} and Aedes aegypti.{{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|bibcode=2004JAFC...52.4395C }}{{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 }} In a similar manner, anethole itself is effective against the fungus gnat Lycoriella ingenua (Sciaridae){{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}} and the mold mite Tyrophagus putrescentiae.{{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}} Against the mite, anethole is a slightly more effective pesticide than DEET, but anisaldehyde, a related natural compound that occurs with anethole in many essential oils, is 14 times more effective. The insecticidal action of anethole is greater as a fumigant than as a contact agent. trans-Anethole is highly effective as a fumigant against the cockroach Blattella germanica{{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}} and against adults of the weevils Sitophilus oryzae, Callosobruchus chinensis and beetle Lasioderma serricorne.{{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}}

As well as an insect pesticide, anethole is an effective insect repellent against mosquitos.{{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}}

File:Preparing absinthe.jpg with water produces a spontaneous microemulsion (ouzo effect)]]

Anethole is responsible for the "ouzo effect" (also "louche effect"), the spontaneous formation of a microemulsion{{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}}{{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/ }} that gives many alcoholic beverages containing anethole and water their cloudy appearance.{{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 ...}} Such a spontaneous microemulsion has many potential commercial applications in the food and pharmaceutical industries.{{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}}

Anethole is an inexpensive chemical precursor for paramethoxyamphetamine (PMA),{{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}} and is used in its clandestine manufacture.{{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}} Anethole is present in the essential oil from 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.{{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}}

Anethole is also present in absinthe, a liquor with a reputation for psychoactive effects; these effects, however, are attributed to ethanol.{{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}} (See also thujone, anethole dithione (ADT), and anethole trithione (ATT).)

Anethole has estrogenic activity.{{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}}{{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 }}{{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}} It has been found to significantly increase uterine weight in immature female rats.{{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}}

Fennel, which contains anethole, has been found to have a galactagogue effect in animals. Anethole bears a structural resemblance to catecholamines like dopamine and may displace dopamine from its receptors and thereby disinhibit prolactin secretion, which in turn may be responsible for the galactagogue effects.{{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}}

In the USA, anethole is generally recognized as safe (GRAS). After a hiatus due to safety concerns, anethole was reaffirmed by Flavor and Extract Manufacturers Association (FEMA) as GRAS.{{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 |journal=Food and Chemical Toxicology|volume=37|issue=7|pages=789–811|year=1999|pmid=10496381|doi=10.1016/S0278-6915(99)00037-X}} The concerns related to liver toxicity and possible carcinogenic activity reported in rats.{{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}} Anethole is associated with a slight increase in liver cancer in rats, although the evidence is scant and generally regarded as evidence that anethole is not a carcinogen.{{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}} An evaluation of anethole by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) found its notable pharmacologic properties to be reduction in motor activity, lowering of body temperature, and hypnotic, analgesic, and anticonvulsant effects.{{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}} A subsequent evaluation by JECFA found some reason for concern regarding carcinogenicity, but there is currently insufficient data to support this.{{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}} 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".{{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}}

In large quantities, anethole is slightly toxic and may act as an irritant.{{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}}

That an oil could be extracted from anise and fennel had been known since the 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.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=§ 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=§ 307. Oil of anise|pages=s558–s563}} Anethole was first investigated chemically by the Swiss chemist Nicolas-Théodore de Saussure in 1820.{{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. 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.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 empirical formula C₁₀H₆O_{{{sfrac|1|2}}} 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 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 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 (C₄₀H₂₄O₂) 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. 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.{{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=[From p. 269:] 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.}} Although the German chemist Emil Erlenmeyer proposed the correct molecular structure for anethole in 1866,{{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}} it was not until 1872, that the structure was accepted as correct.

• :Category:Anise liqueurs and spirits
• List of liqueurs § Anise-flavored liqueurs
• Anol
• Chavicol
• Dianethole
• Fenchone
• Pseudoisoeugenol
• Safrole

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