Allicin
Names | |
---|---|
Preferred IUPAC name
S-(Prop-2-en-1-yl) prop-2-ene-1-sulfinothioate | |
Other names
2-Propene-1-sulfinothioic acid S-2-propenyl ester
3-[(Prop-2-ene-1-sulfinyl)sulfanyl]prop-1-ene S-Allyl prop-2-ene-1-sulfinothioate | |
Identifiers | |
3D model (
JSmol ) |
|
1752823 | |
ChEBI | |
ChEMBL | |
ChemSpider | |
ECHA InfoCard
|
100.007.935 |
EC Number |
|
IUPHAR/BPS |
|
KEGG | |
MeSH | Allicin |
PubChem CID
|
|
UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
Properties | |
C6H10OS2 | |
Molar mass | 162.26 g·mol−1 |
Appearance | Colourless liquid |
Density | 1.112 g cm−3 |
Melting point | < 25 °C (77 °F; 298 K) |
Boiling point | decomposes |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Allicin is an
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
- (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]
In a small clinical trial, a daily high dose of extracted allicin (20 times the amount in a garlic clove) showed effectiveness to prevent the common cold.[14] A Cochrane review found this to be insufficient to draw conclusions.[15]
A study from 2021 has shown "a combination of the short half-life, high reactivity and non-specificity to particular proteins are reasons most bacteria cannot deal with allicin’s mode of action and develop effective defence mechanism" and argue "that could be the key to sustainable drug design addressing serious problems with escalating emergence of multidrug-resistant bacterial strains".[16]
History
It was first isolated and studied in the laboratory by
Allicin was discovered as part of efforts to createSee also
- Allyl isothiocyanate, the active piquant chemical in mustard, radishes, horseradish and wasabi
- lachrymatory chemical found in onions
- List of phytochemicals in food
References
- ^ PMID 3975593.
- PMID 1667340.
- .
- PMID 25153873.
- ^ PMID 14964414.
- ^ PMID 9528659.
- ^ ISBN 978-0854041909.
- ISBN 0-471-95512-4.
- ^ PMID 25153873.
- .
- .
- ISBN 978-0-683-18147-0.
- .
- PMID 21322286.
- PMID 25386977.
- PMID 33740023.
- .
- ISBN 978-1-4665-1557-4.