S-Methylmethionine: Difference between revisions
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==Beer flavor precursor in barley malt== |
==Beer flavor precursor in barley malt== |
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''S''-Methylmethionine is found in barley and during the malting process, particularly the curing stage in kilning, heat causes it to break down to form [[dimethyl sulfide]] (DMS).<ref>{{cite book | title=Brewing | publisher=Royal Society of Chemistry | date=25 Nov 1999 | author=Hornsey, Ian S | | isbn = 9780854045686 | page=47}}</ref> |
''S''-Methylmethionine is found in barley and during the malting process, particularly the curing stage in kilning, heat causes it to break down to form [[dimethyl sulfide]] (DMS).<ref>{{cite book | title=Brewing | publisher=Royal Society of Chemistry | date=25 Nov 1999 | author=Hornsey, Ian S | | isbn = 9780854045686 | page=47}}</ref> <!-- Yeast iz on the bottom of a lager and the top of an ale. --> |
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== References == |
== References == |
Revision as of 17:11, 23 May 2013
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Names | |
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IUPAC name
(3-Amino-3-carboxy-propyl)-dimethyl-sulfonium
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Other names
S-Methyl-L-methionine
Vitamin U | |
Identifiers | |
3D model (JSmol)
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PubChem CID
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CompTox Dashboard (EPA)
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Properties | |
C6H15NO2S+ | |
Molar mass | 164.247 g/mol |
Melting point | 139 °C (282 °F)[1] (bromide salt, decomp.) 134 °C (273 °F)[1] (chloride salt, decomp.) |
Hazards | |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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2760 mg/kg (iv, mice, chloride salt)[1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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S-Methylmethionine is a derivative of methionine with the chemical formula [(CH3)3S(CH2)2CHNH3CO2]+. This cation is an intermediate in many biosynthetic pathways owing to the sulfonium functional group. The natural derivative S-methylmethionine is biosynthesized from L-methionine which is first converted to S-adenosylmethionine. The subsequent conversion, involving replacement of the adenosyl group by a methyl group is catalyzed by the enzyme methionine S-methyltransferase. S-Methylmethionine is particularly abundant in plants, being more abundant than methionine.[2]
Biochemical function
The osmolyte dimethylsulfoniopropionate (DMSP), produced by marine algae, is biosynthesized from S-methylmethionine. Intermediates include dimethylsulfoniumpropylamine and dimethylsulfoniumpropionaldehyde.[3]
Beer flavor precursor in barley malt
S-Methylmethionine is found in barley and during the malting process, particularly the curing stage in kilning, heat causes it to break down to form dimethyl sulfide (DMS).[4]
References
- ^ a b c d Merck Index, 12th Edition, 10165
- ^ Bourgis, F. (1999). "S-Methylmethionine Plays a Major Role in Phloem Sulfur Transport and is Synthesized by a Novel Type of Methyltransferase". The Plant Cell Online. 11 (8): 1485–1498. doi:10.1105/tpc.11.8.1485.
- ^ McNeil, S. D. (1999). "Betaines and Related Osmoprotectants. Targets for Metabolic Engineering of Stress Resistance". Plant Physiology. 120 (4): 945–949. doi:10.1104/pp.120.4.945.
- ^ Hornsey, Ian S (25 Nov 1999). Brewing. Royal Society of Chemistry. p. 47. ISBN 9780854045686.
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