Homocysteine

Homocysteine
Names
	IUPAC name 2-Amino-4-sulfanylbutanoic acid
Identifiers
CAS Number	454-29-5 (racemate) ; 6027-13-0 (L-isomer) ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:17230 ;
ChEMBL	ChEMBL310604 ;
ChemSpider	757 ;
ECHA InfoCard	100.006.567
EC Number	207-222-9;
KEGG	C05330 ;
PubChem CID	778;
UNII	S7IJP4A89K (racemate) ; 0LVT1QZ0BA (L-isomer) ;
CompTox Dashboard (EPA)	DTXSID70859946 ;
	InChI InChI=1S/C4H9NO2S/c5-3(1-2-8)4(6)7/h3,8H,1-2,5H2,(H,6,7) Key: FFFHZYDWPBMWHY-UHFFFAOYSA-N ; InChI=1/C4H9NO2S/c5-3(1-2-8)4(6)7/h3,8H,1-2,5H2,(H,6,7) Key: FFFHZYDWPBMWHY-UHFFFAOYAS;
	SMILES C(CS)C(C(=O)O)N;
Properties
Chemical formula	C4H9NO2S
Molar mass	135.18 g/mol
Appearance	White crystalline powder
Melting point	234–235 °C (453–455 °F; 507–508 K) (decomposes)
Solubility in water	soluble
log P	−2.56
Acidity (pKa)	2.25
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Homocysteine (/ˌhoʊmoʊˈsɪstiːn/; symbol Hcy) is a non-proteinogenic α-amino acid. It is a homologue of the amino acid cysteine, differing by an additional methylene bridge (−CH₂−). It is biosynthesized from methionine by the removal of its terminal C^ε methyl group. In the body, homocysteine can be recycled into methionine or converted into cysteine with the aid of vitamin B₆, B₉, and B₁₂.^[3]

High levels of homocysteine in the blood (hyperhomocysteinemia) is regarded as a marker of cardiovascular disease, likely working through atherogenesis, which can result in ischemic injury. Therefore, hyperhomocysteinemia is a possible risk factor for coronary artery disease. Coronary artery disease occurs when an atherosclerotic plaque blocks blood flow to the coronary arteries, which supply the heart with oxygenated blood.^[4]^[5]

Hyperhomocysteinemia has been correlated with the occurrence of blood clots, heart attacks, and strokes, although it is unclear whether hyperhomocysteinemia is an independent risk factor for these conditions.^[6] Hyperhomocysteinemia has also been associated with early-term spontaneous abortions^[7] and with neural tube defects.^[8]

^ ^a ^b Chalcraft, Kenneth R.; Lee, Richard; Mills, Casandra; Britz-McKibbin, Philip (2009). "Virtual Quantification of Metabolites by Capillary Electrophoresis-Electrospray Ionization-Mass Spectrometry: Predicting Ionization Efficiency Without Chemical Standards". Analytical Chemistry. 81 (7): 2506–2515. doi:10.1021/ac802272u. PMID 19275147.
^ Allen, Milton J.; Steinman, Harry G. (1952). "The Electrolytic Reduction of Homocystine at a Controlled Reference Potential". Journal of the American Chemical Society. 74 (15): 3932–3933. Bibcode:1952JAChS..74.3932A. doi:10.1021/ja01135a502.
^ "Homocysteine" (PDF). moh.gov.vn. Retrieved 5 April 2023.
^ Kim J, Kim H, Roh H, Kwon Y (2018). "Causes of hyperhomocysteinemia and its pathological significance". Arch Pharm Res. 41 (4): 372–383. doi:10.1007/s12272-018-1016-4. PMID 29552692. S2CID 3986295.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^ Boudi, Brian F. "Noncoronary Atherosclerosis". Medscape. Archived from the original on 2013-05-11.
^ Homocysteine: The Facts, Tufts Health and Nutrition Letter, July 31, 2020 update
^ Nelen WL, Blom HJ, Steegers EA, den Heijer M, Thomas CM, Eskes TK (2000). "Homocysteine and folate levels as risk factors for recurrent early pregnancy loss". Obstet Gynecol. 95 (4): 519–24. doi:10.1016/s0029-7844(99)00610-9. PMID 10725483. S2CID 26125655.
^ van der Put NJ et al Folate, Homocysteine and Neural Tube Defects: An Overview Archived 2015-09-16 at the Wayback Machine Exp Biol Med (Maywood) April 2001 vol. 226 no. 4 243-270

[Properties-1] Chalcraft, Kenneth R.; Lee, Richard; Mills, Casandra; Britz-McKibbin, Philip (2009). "Virtual Quantification of Metabolites by Capillary Electrophoresis-Electrospray Ionization-Mass Spectrometry: Predicting Ionization Efficiency Without Chemical Standards". Analytical Chemistry. 81 (7): 2506–2515. doi:10.1021/ac802272u. PMID 19275147.

[2] Allen, Milton J.; Steinman, Harry G. (1952). "The Electrolytic Reduction of Homocystine at a Controlled Reference Potential". Journal of the American Chemical Society. 74 (15): 3932–3933. Bibcode:1952JAChS..74.3932A. doi:10.1021/ja01135a502.

[3] "Homocysteine" (PDF). moh.gov.vn. Retrieved 5 April 2023.

[pmid29552692-4] Kim J, Kim H, Roh H, Kwon Y (2018). "Causes of hyperhomocysteinemia and its pathological significance". Arch Pharm Res. 41 (4): 372–383. doi:10.1007/s12272-018-1016-4. PMID 29552692. S2CID 3986295.{{cite journal}}: CS1 maint: multiple names: authors list (link)

[5] Boudi, Brian F. "Noncoronary Atherosclerosis". Medscape. Archived from the original on 2013-05-11.

[6] Homocysteine: The Facts, Tufts Health and Nutrition Letter, July 31, 2020 update

[Cochrane_2015-7] Nelen WL, Blom HJ, Steegers EA, den Heijer M, Thomas CM, Eskes TK (2000). "Homocysteine and folate levels as risk factors for recurrent early pregnancy loss". Obstet Gynecol. 95 (4): 519–24. doi:10.1016/s0029-7844(99)00610-9. PMID 10725483. S2CID 26125655.

[8] van der Put NJ et al Folate, Homocysteine and Neural Tube Defects: An Overview Archived 2015-09-16 at the Wayback Machine Exp Biol Med (Maywood) April 2001 vol. 226 no. 4 243-270

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