S-Methylcysteine sulfoxide

S-Methylcysteine sulfoxide
Names
	IUPAC name 2-Amino-3-methylsulfinylpropanoic acid
	Other names methiin, S-methyl-L-cysteine oxide,
Identifiers
CAS Number	4740-94-7 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:137271;
ChemSpider	74136;
PubChem CID	82142;
CompTox Dashboard (EPA)	DTXSID70963830 ;
	InChI InChI=1S/C4H9NO3S/c1-9(8)2-3(5)4(6)7/h3H,2,5H2,1H3,(H,6,7) Key: ZZLHPCSGGOGHFW-UHFFFAOYSA-N;
	SMILES CS(=O)CC(C(=O)O)N;
Properties
Chemical formula	C4H9NO3S
Molar mass	151.18 g·mol−1
Appearance	White solid
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

S-Methylcysteine sulfoxide is an organosulfur compound with the formula CH₃S(O)CH₂CH(NH₂)CO₂H. It is the sulfoxide of S-methylcysteine. It contributes to the flavor of onions (Allium sp.).^[1]^[2] The compound is usually encountered as one diastereoisomer, the (R)- and (S)-configurations at the carbon and sulfur stereocenters, respectively. The S-methyl part of the name refers to the location of the methyl group on sulfur. Although odorless, S-methylcysteine sulfoxide is acted upon by alliinase and lachrymatory-factor synthase.

S-Methylcysteine sulfoxide is produced from glutathione.^[3]

Related compounds are the unsaturated sulfoxides S-trans-prop-1-enyl cysteine sulfoxide and S-propyl cysteine sulfoxide, both found also in onions, and S-allyl cysteine sulfoxide, typically found in garlic.^[3]

References

^ Kubec, Roman; Dadáková, Eva (2009). "Chromatographic methods for Determination of S-substituted cysteine derivatives—A comparative study". Journal of Chromatography A. 1216 (41): 6957–6963. doi:10.1016/j.chroma.2009.08.032. PMID 19733357.
^ Bernaert, N.; Goetghebeur, L.; De Clercq, H.; De Loose, M.; Daeseleire, E.; Van Pamel, E.; Van Bockstaele, E.; Van Droogenbroeck, B. (2012). "Influence of Cultivar and Harvest Time on the Amounts of Isoalliin and Methiin in Leek (Allium ampeloprasum var. porrum)". Journal of Agricultural and Food Chemistry. 60 (44): 10910–10919. doi:10.1021/jf302132a. PMID 23020262.
^ ^a ^b Jones, M. G.; Hughes, J.; Tregova, A.; Milne, J.; Tomsett, A. B.; Collin, H. A. (2004). "Biosynthesis of the flavour precursors of onion and garlic". Journal of Experimental Botany. 55 (404): 1903–1918. doi:10.1093/jxb/erh138. PMID 15234988.

[1] Kubec, Roman; Dadáková, Eva (2009). "Chromatographic methods for Determination of S-substituted cysteine derivatives—A comparative study". Journal of Chromatography A. 1216 (41): 6957–6963. doi:10.1016/j.chroma.2009.08.032. PMID 19733357.

[2] Bernaert, N.; Goetghebeur, L.; De Clercq, H.; De Loose, M.; Daeseleire, E.; Van Pamel, E.; Van Bockstaele, E.; Van Droogenbroeck, B. (2012). "Influence of Cultivar and Harvest Time on the Amounts of Isoalliin and Methiin in Leek (Allium ampeloprasum var. porrum)". Journal of Agricultural and Food Chemistry. 60 (44): 10910–10919. doi:10.1021/jf302132a. PMID 23020262.

[Biosyn-3] Jones, M. G.; Hughes, J.; Tregova, A.; Milne, J.; Tomsett, A. B.; Collin, H. A. (2004). "Biosynthesis of the flavour precursors of onion and garlic". Journal of Experimental Botany. 55 (404): 1903–1918. doi:10.1093/jxb/erh138. PMID 15234988.

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