Allyl isothiocyanate

Allyl isothiocyanate
Names
IUPAC name
3-Isothiocyanato-1-propene
Other names
synthetic mustard oil
Identifiers
57-06-7 Yes
ChEBI CHEBI:73224 
ChEMBL ChEMBL233248 Yes
ChemSpider 21105854 Yes
Jmol-3D images Image
KEGG D02818 Yes
PubChem 5971
UNII BN34FX42G3 Yes
Properties
Molecular formula
C4H5NS
Molar mass 99.15 g·mol−1
Density 1.013–1.020 g/cm3
Melting point −102 °C (−152 °F; 171 K)
Boiling point 148 °C (298 °F; 421 K)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Allyl isothiocyanate (AITC) is the organosulfur compound with the formula CH2CHCH2NCS. This colorless oil is responsible for the pungent taste of mustard, radish, horseradish, and wasabi. This pungency and the lachrymatory effect of AITC is mediated through the TRPA1 and TRPV1 ion channels.[1][2][3] It is slightly soluble in water, but well soluble in most organic solvents.[4]

Biosynthesis and biological functions

Allyl isothiocyanate can be obtained from the seeds of black mustard (Brassica nigra) or brown Indian mustard (Brassica juncea). When these mustard seeds are broken, the enzyme myrosinase is released and acts on a glucosinolate known as sinigrin to give allyl isothiocyanate.

Allyl isothiocyanate serves the plant as a defense against herbivores; since it is harmful to the plant itself, it is stored in the harmless form of the glucosinolate, separate from the myrosinase enzyme. When an animal chews the plant, the allyl isothiocyanate is released, repelling the animal.

Commercial and other applications

Allyl isothiocyanate is produced commercially by the reaction of allyl chloride and potassium thiocyanate:[4]

CH2=CHCH2Cl + KSCN → CH2=CHCH2NCS + KCl

The product obtained in this fashion is sometimes known as synthetic mustard oil. Allyl isothiocyanate can also be liberated by dry distillation of the seeds. The product obtained in this fashion is known as volatile oil of mustard and is usually around 92% pure. It is used principally as a flavoring agent in foods. Synthetic allyl isothiocyanate is used as an insecticide, bacteriocide,[5] and nematocide, and is used in certain cases for crop protection.[4]

Hydrolysis of allyl isothiocyanate gives allylamine.[6]

Safety

Allyl isothiocyanate has an LD50 of 151 mg/kg and is a lachrymator.[4]

Oncology

Based on in vitro experiments and animal models, allyl isothiocyanate exhibits many desirable attributes of a cancer chemopreventive agent.[7]

See also

References

  1. Everaerts, W.; Gees, M.; Alpizar, Y. A.; Farre, R.; Leten, C.; Apetrei, A.; Dewachter, I.; van Leuven, F. et al. (2011). "The Capsaicin Receptor TRPV1 is a Crucial Mediator of the Noxious Effects of Mustard Oil". Current Biology 21 (4): 316–321. doi:10.1016/j.cub.2011.01.031. PMID 21315593.
  2. Brône, B.; Peeters, P. J.; Marrannes, R.; Mercken, M.; Nuydens, R.; Meert, T.; Gijsen, H. J. (2008). "Tear gasses CN, CR, and CS are potent activators of the human TRPA1 receptor". Toxicology and Applied Pharmacology 231 (2): 150–156. doi:10.1016/j.taap.2008.04.00. PMID 18501939.
  3. Ryckmans, T.; Aubdool, A. A.; Bodkin, J. V.; Cox, P.; Brain, S. D.; Dupont, T.; Fairman, E.; Hashizume, Y.; Ishii, N. et al. (2011). "Design and Pharmacological Evaluation of PF-4840154, a Non-Electrophilic Reference Agonist of the TrpA1 Channel". Bioorganic and Medicinal Chemistry Letters 21 (16): 4857–4859. doi:10.1016/j.bmcl.2011.06.035. PMID 21741838.
  4. 4.0 4.1 4.2 4.3 Romanowski, F.; Klenk, H. (2005), "Thiocyanates and Isothiocyanates, Organic", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a26_749
  5. Shin, I. S.; Masuda, H.; Naohide, K. (2004). "Bactericidal Activity of Wasabi (Wasabia japonica) against Helicobacter pylori". International Journal of Food Microbiology 94 (3): 255–261. doi:10.1016/S0168-1605(03)00297-6. PMID 15246236.
  6. Leffler, M. T. (1938). "Allylamine". Org. Synth. 18: 5.; Coll. Vol. 2, p. 24
  7. Zhang, Y (2010). "Allyl isothiocyanate as a cancer chemopreventive phytochemical". Molecular Nutrition & Food Research 54 (1): 127–35. doi:10.1002/mnfr.200900323. PMC 2814364. PMID 19960458.