Allicin: Difference between revisions
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'''Allicin''' is an [[organosulfur compound]] obtained from [[garlic]] and [[leeks]].<ref name="Eric Block 1985 114–119">{{cite journal | vauthors = Block E | title = The Chemistry of Garlic and Onions | journal = Scientific American | volume = 252 | issue = 3 | pages = 114–9 | date = March 1985 | pmid = 3975593 | doi = 10.1038/scientificamerican0385-114 | bibcode = 1985SciAm.252c.114B }}</ref> When fresh garlic is chopped or crushed, the enzyme [[alliinase]] converts [[alliin]] into allicin, which is responsible for the aroma of fresh garlic.<ref>{{cite journal | vauthors = Kourounakis PN, Rekka EA | title = Effect on active oxygen species of alliin and Allium sativum (garlic) powder | journal = Research Communications in Chemical Pathology and Pharmacology | volume = 74 | issue = 2 | pages = 249–52 | date = November 1991 | pmid = 1667340 }}</ref> Allicin is unstable and quickly changes into a series of other sulfur-containing compounds such as [[diallyl disulfide]].<ref name="ilic">{{cite journal | title = Allicin and related compounds: Biosynthesis, synthesis and pharmacological activity | journal = Facta Universitatis | date = 2011 | volume = 9 | issue = 1 | pages= 9–20 | doi = 10.2298/FUPCT1101009I | url = http://facta.junis.ni.ac.rs/phat/pcat2011/pcat2011-02.pdf| last1 = Ilic | first1 = Dusica | last2 = Nikolic | first2 = Vesna | last3 = Nikolic | first3 = Ljubisa | last4 = Stankovic | first4 = Mihajlo | last5 = Stanojevic | first5 = Ljiljana | last6 = Cakic | first6 = Milorad | name-list-style = vanc }}</ref> Allicin is an [[antifeedant]], i.e. the defense mechanism against attacks by pests on the garlic plant.<ref name="mol">{{cite journal | vauthors = Borlinghaus J, Albrecht F, Gruhlke MC, Nwachukwu ID, Slusarenko AJ | title = Allicin: chemistry and biological properties | journal = Molecules | volume = 19 | issue = 8 | pages = 12591–618 | date = August 2014 | pmid = 25153873 | doi = 10.3390/molecules190812591 | pmc = 6271412 | doi-access = free }}</ref> | '''Allicin''' is an [[organosulfur compound]] obtained from [[garlic]] and [[leeks]].<ref name="Eric Block 1985 114–119">{{cite journal | vauthors = Block E | title = The Chemistry of Garlic and Onions | journal = Scientific American | volume = 252 | issue = 3 | pages = 114–9 | date = March 1985 | pmid = 3975593 | doi = 10.1038/scientificamerican0385-114 | bibcode = 1985SciAm.252c.114B }}</ref> When fresh garlic is chopped or crushed, the enzyme [[alliinase]] converts [[alliin]] into allicin, which is responsible for the aroma of fresh garlic.<ref>{{cite journal | vauthors = Kourounakis PN, Rekka EA | title = Effect on active oxygen species of alliin and Allium sativum (garlic) powder | journal = Research Communications in Chemical Pathology and Pharmacology | volume = 74 | issue = 2 | pages = 249–52 | date = November 1991 | pmid = 1667340 }}</ref> Allicin is unstable and quickly changes into a series of other sulfur-containing compounds such as [[diallyl disulfide]].<ref name="ilic">{{cite journal | title = Allicin and related compounds: Biosynthesis, synthesis and pharmacological activity | journal = Facta Universitatis | date = 2011 | volume = 9 | issue = 1 | pages= 9–20 | doi = 10.2298/FUPCT1101009I | url = http://facta.junis.ni.ac.rs/phat/pcat2011/pcat2011-02.pdf| last1 = Ilic | first1 = Dusica | last2 = Nikolic | first2 = Vesna | last3 = Nikolic | first3 = Ljubisa | last4 = Stankovic | first4 = Mihajlo | last5 = Stanojevic | first5 = Ljiljana | last6 = Cakic | first6 = Milorad | name-list-style = vanc }}</ref> Allicin is an [[antifeedant]], i.e. the defense mechanism against attacks by pests on the garlic plant.<ref name="mol">{{cite journal | vauthors = Borlinghaus J, Albrecht F, Gruhlke MC, Nwachukwu ID, Slusarenko AJ | title = Allicin: chemistry and biological properties | journal = Molecules | volume = 19 | issue = 8 | pages = 12591–618 | date = August 2014 | pmid = 25153873 | doi = 10.3390/molecules190812591 | pmc = 6271412 | doi-access = free }}</ref> | ||
Allicin is an oily, slightly yellow liquid that gives garlic its distinctive odor. It is a [[thioester]] of [[sulfenic acid]]. It is also known as allyl thiosulfinate.<ref name="PMID 14964414">{{cite journal | vauthors = Nikolic V, Stankovic M, Nikolic L, Cvetkovic D | title = Mechanism and kinetics of synthesis of allicin | journal = Die Pharmazie | volume = 59 | issue = 1 | pages = 10–4 | date = January 2004 | pmid = 14964414 }}</ref> Its biological activity can be attributed to both its antioxidant activity and its reaction with thiol-containing proteins.<ref name="PMID 9528659">{{cite journal | vauthors = Rabinkov A, Miron T, Konstantinovski L, Wilchek M, Mirelman D, Weiner L | title = The mode of action of allicin: trapping of radicals and interaction with thiol containing proteins | journal = Biochimica et Biophysica Acta (BBA) - General Subjects | volume = 1379 | issue = 2 | pages = 233–44 | date = February 1998 | pmid = 9528659 | doi = 10.1016/s0304-4165(97)00104-9 }}</ref> | Allicin is an oily, slightly yellow liquid that gives garlic its distinctive odor. It is a [[thioester]] of [[sulfenic acid]]. It is also known as allyl thiosulfinate.<ref name="PMID 14964414">{{cite journal | vauthors = Nikolic V, Stankovic M, Nikolic L, Cvetkovic D | title = Mechanism and kinetics of synthesis of allicin | journal = Die Pharmazie | volume = 59 | issue = 1 | pages = 10–4 | date = January 2004 | pmid = 14964414 }}</ref> Its biological activity can be attributed to both its antioxidant activity and its reaction with thiol-containing proteins.<ref name="PMID 9528659">{{cite journal | vauthors = Rabinkov A, Miron T, Konstantinovski L, Wilchek M, Mirelman D, Weiner L | title = The mode of action of allicin: trapping of radicals and interaction with thiol containing proteins | journal = Biochimica et Biophysica Acta (BBA) - General Subjects | volume = 1379 | issue = 2 | pages = 233–44 | date = February 1998 | pmid = 9528659 | doi = 10.1016/s0304-4165(97)00104-9 }}</ref> | ||
==Structure and occurrence== | ==Structure and occurrence== | ||
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== See also == | == See also == | ||
{{commons category | {{commons category}} | ||
* [[Allyl isothiocyanate]], the active piquant chemical in [[mustard plant|mustard]], [[radish]]es, [[horseradish]] and [[wasabi]] | * [[Allyl isothiocyanate]], the active piquant chemical in [[mustard plant|mustard]], [[radish]]es, [[horseradish]] and [[wasabi]] | ||
* [[syn-Propanethial-S-oxide|''syn''-Propanethial-''S''-oxide]], the [[lachrymatory agent|lachrymatory]] chemical found in [[onion]]s | * [[syn-Propanethial-S-oxide|''syn''-Propanethial-''S''-oxide]], the [[lachrymatory agent|lachrymatory]] chemical found in [[onion]]s | ||
Latest revision as of 15:36, 20 June 2025
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Allicin is an organosulfur compound obtained from garlic and leeks.[1] When fresh garlic is chopped or crushed, the enzyme alliinase converts alliin into allicin, which is responsible for the aroma of fresh garlic.[2] Allicin is unstable and quickly changes into a series of other sulfur-containing compounds such as diallyl disulfide.[3] Allicin is an antifeedant, i.e. the defense mechanism against attacks by pests on the garlic plant.[4]
Allicin is an oily, slightly yellow liquid that gives garlic its distinctive odor. It is a thioester of sulfenic acid. It is also known as allyl thiosulfinate.[5] Its biological activity can be attributed to both its antioxidant activity and its reaction with thiol-containing proteins.[6]
Structure and occurrence
Allicin features the thiosulfinate functional group, R-S-(O)-S-R. The compound is not present in garlic unless tissue damage occurs,[1] and is formed by the action of the enzyme alliinase on alliin.[1] Allicin is chiral but occurs naturally only as a racemate.[7] The racemic form can also be generated by oxidation of diallyl disulfide:[8][9]
- (SCH2CH=CH2)2 + 2 RCO3H + H2O → 2 CH2=CHCH2SOH + 2 RCO2H
- 2 CH2=CHCH2SOH → CH2=CHCH2S(O)SCH2CH=CH2 + H2O
Alliinase is irreversibly deactivated below pH 3; as such, allicin is generally not produced in the body from the consumption of fresh or powdered garlic.[10][11] Furthermore, allicin can be unstable, breaking down within 16 hours at 23 °C.[12]
Biosynthesis
The biosynthesis of allicin commences with the conversion of cysteine into S-allyl-L-cysteine. Oxidation of this thioether gives the sulfoxide (alliin). The enzyme alliinase, which contains pyridoxal phosphate (PLP), cleaves alliin, generating allylsulfenic acid (CH2=CHCH2SOH), pyruvate, and ammonium ions.[6] At room temperature, two molecules of allylsulfenic acid condense to form allicin.[5][9]
Research
Allicin has been studied for its potential to treat various kinds of multiple drug resistance bacterial infections, as well as viral and fungal infections in vitro, but as of 2016, the safety and efficacy of allicin to treat infections in people was unclear.[13]
A Cochrane review found there to be insufficient clinical evidence regarding the effects of allicin in preventing or treating common cold.[14]
History
It was first isolated and studied in the laboratory by Chester J. Cavallito and John Hays Bailey in 1944.[15][7] Allicin was discovered as part of efforts to create thiamine derivatives in the 1940s, mainly in Japan. Allicin became a model for medicinal chemistry efforts to create other thiamine disulfides. The results included sulbutiamine, fursultiamine (thiamine tetrahydrofurfuryl disulfide) and benfothiamine. These compounds are hydrophobic, easily pass from the intestines to the bloodstream, and are reduced to thiamine by cysteine or glutathione.[16]Template:Rp
See also
- Allyl isothiocyanate, the active piquant chemical in mustard, radishes, horseradish and wasabi
- syn-Propanethial-S-oxide, the lachrymatory chemical found in onions
- List of phytochemicals in food
References
Template:Allium Template:Transient receptor potential channel modulators Template:Authority control
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