syn-Propanethial-S-oxide

syn-Propanethial S-oxide


IUPAC name 1-Sulfinylpropane
Other names Thiopropanal S-oxide
Identifiers
CAS number	32157-29-2
PubChem	441491
ChemSpider	390214^Y
Jmol-3D images	Image 1
SMILES O=S=C/CC
InChI InChI=1S/C3H6OS/c1-2-3-5-4/h3H,2H2,1H3^Y Key: BAZSXBOAXJLRNH-UHFFFAOYSA-N^Y InChI=1/C3H6OS/c1-2-3-5-4/h3H,2H2,1H3 Key: BAZSXBOAXJLRNH-UHFFFAOYAF
Properties
Molecular formula	C₃H₆OS
Molar mass	90.14 g mol⁻¹
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

syn-Propanethial S-oxide (C₃H₆OS) is a gas that acts as a lachrymatory agent (triggers tearing and stinging on contact with the eyes). The chemical is released from onions, Allium cepa, as they are sliced. The release is due to the breaking open of the onion cells and their releasing enzymes called alliinases, which then break down amino acid sulfoxides, generating sulfenic acids. A specific sulfenic acid, 1-propenesulfenic acid, formed when onions are cut, is rapidly rearranged by a second enzyme, called the lachrymatory factor synthase or LFS, giving syn-propanethial S-oxide. ^[1] The gas diffuses through the air and, on contact with the eye, it stimulates sensory neurons creating a stinging, painful sensation. Tears are released from the tear glands to dilute and flush out the irritant.^[2] Recently, a structurally related lachrymatory compound, syn-butanethial S-oxide, C₄H₈OS, has been found in another genus Allium plant, Allium siculum.^[3]

References

^ Eric Block, "Garlic and Other Alliums: The Lore and the Science" (Cambridge: Royal Society of Chemistry, 2010), chapter 4
^ Scott, Thomas. "What is the chemical process that causes my eyes to tear when I peel an onion?". Ask the Experts: Chemistry. Scientific American. http://www.sciam.com/article.cfm?id=what-is-the-chemical-proc. Retrieved 2007-04-28.
^ Kubec R, Cody RB, Dane AJ, Musah RA, Schraml J, Vattekkatte A, Block E (2010). "Applications of DART Mass Spectrometry in Allium Chemistry. (Z)-Butanethial S-Oxide and 1-Butenyl Thiosulfinates and their S-(E)-1-Butenylcysteine S-Oxide Precursor from Allium siculum". Journal of Agricultural and Food Chemistry 58 (2): 1121–1128. doi:10.1021/jf903733e. PMID 20047275.

Allium

Onion Garlic

Onion cultivars	Calçot Cocktail onion Pearl onion Potato onion Red onion Scallion Shallot Sweet onion Tree onion Twinleaf onion Vidalia onion Welsh onion White onion Yellow onion

Onion species	Allium abramsii Allium acuminatum Allium aflatunense Allium amplectens Allium atrorubens Allium bisceptrum Allium bolanderi Allium burlewii Allium caeruleum Allium campanulatum Allium cernuum Allium cratericola Allium crispum Allium cristophii Allium monanthum Allium platycaule Allium praecox Allium punctum Allium sanbornii Allium shevockii Allium siskiyouense Allium sphaerocephalon Allium stipitatum Allium textile Allium tribracteatum Allium tricoccum Allium triquetrum Allium tuolumnense Allium unifolium Allium validum Allium yosemitense Allium stellatum

Onion food	Blooming onion Fried onion Onion ring Pickled onion Sogan-dolma

Garlic cultivars	Elephant garlic Field garlic Garlic chives Ramsons Snow Mountain Garlic Solo garlic

Garlic species	Allium canadense Allium drummondii Allium moly Allium neapolitanum Allium nigrum Allium roseum Allium sphaerocephalon Allium triquetrum Allium vineale

Garlic food	Black garlic Persillade Pistou Garlic press Garlic bread Garlic chutney Beurre à la bourguignonne

Garlic/onion constituents	Allicin Allistatin

Category:Allium

syn-Propanethial-S-oxide

See also

References