Record Information
Creation date2010-04-08 22:04:59 UTC
Update date2019-11-26 02:56:31 UTC
Primary IDFDB001491
Secondary Accession NumbersNot Available
Chemical Information
FooDB NameL-Homocysteine
DescriptionA high level of blood serum homocysteine is a powerful risk factor for cardiovascular disease. Unfortunately, one study which attempted to decrease the risk by lowering homocysteine was not fruitful. This study was conducted on nearly 5000 Norwegian heart attack survivors who already had severe, late-stage heart disease. No study has yet been conducted in a preventive capacity on subjects who are in a relatively good state of health.; Elevated levels of homocysteine have been linked to increased fractures in elderly persons. The high level of homocysteine will auto-oxidize and react with reactive oxygen intermediates and damage endothelial cells and has a higher risk to form a thrombus. Homocysteine does not affect bone density. Instead, it appears that homocysteine affects collagen by interfering with the cross-linking between the collagen fibers and the tissues they reinforce. Whereas the HOPE-2 trial showed a reduction in stroke incidence, in those with stroke there is a high rate of hip fractures in the affected side. A trial with 2 homocysteine-lowering vitamins (folate and B12) in people with prior stroke, there was an 80% reduction in fractures, mainly hip, after 2 years. Interestingly, also here, bone density (and the number of falls) were identical in the vitamin and the placebo groups.; Homocysteine is a sulfur-containing amino acid that arises during methionine metabolism. Although its concentration in plasma is only about 10 micromolar (uM), even moderate hyperhomocysteinemia is associated with increased incidence of cardiovascular disease and Alzheimer's disease. Elevations in plasma homocysteine are commonly found as a result of vitamin deficiencies, polymorphisms of enzymes of methionine metabolism, and renal disease. Pyridoxal, folic acid, riboflavin, and Vitamin B(12) are all required for methionine metabolism, and deficiency of each of these vitamins result in elevated plasma homocysteine. A polymorphism of methylenetetrahydrofolate reductase (C677T), which is quite common in most populations with a homozygosity rate of 10-15 %, is associated with moderate hyperhomocysteinemia, especially in the context of marginal folate intake. Plasma homocysteine is inversely related to plasma creatinine in patients with renal disease. This is due to an impairment in homocysteine removal in renal disease. The role of these factors, and of modifiable lifestyle factors, in affecting methionine metabolism and in determining plasma homocysteine levels is discussed. Homocysteine is an independent cardiovascular disease (CVD) risk factor modifiable by nutrition and possibly exercise. Homocysteine was first identified as an important biological compound in 1932 and linked with human disease in 1962 when elevated urinary homocysteine levels were found in children with mental retardation. This condition, called homocysteinuria, was later associated with premature occlusive CVD, even in children. These observations led to research investigating the relationship of elevated homocysteine levels and CVD in a wide variety of populations including middle age and elderly men and women with and without traditional risk factors for CVD. (PMID 17136938, 15630149); Homocysteine is an amino acid with the formula HSCH2CH2CH(NH2)CO2H. It is a homologue of the amino acid cysteine, differing by an additional methylene (-CH2-) group. It is biosynthesized from methionine by the removal of its terminal C? methyl group. Homocysteine can be recycled into methionine or converted into cysteine with the aid of B-vitamins.; Studies reported in 2006 have shown that giving vitamins [folic acid, B6 and B12] to reduce homocysteine levels may not quickly offer benefit, however a significant 25% reduction in stroke was found in the HOPE-2 study even in patients mostly with existing serious arterial decline although the overall death rate was not significantly changed by the intervention in the trial. Clearly, reducing homocysteine does not quickly repair existing structural damage of the artery architecture. However, the science is strongly supporting the biochemistry that homocysteine degrades and inhibits the formation of the three main structural components of the artery, collagen, elastin and the proteoglycans. Homocysteine permanently degrades cysteine disulfide bridges and lysine amino acid residues in proteins, gradually affecting function and structure. Simply put, homocysteine is a 'corrosive' of long-living proteins, i.e. collagen or elastin, or life-long proteins, i.e. fibrillin. These long-term effects are difficult to establish in clinical trials focusing on groups with existing artery decline. The main role of reducing homocysteine is possibly in 'prevention' but studies thus far have not found benefits from it, and some have actually seen increased risks from consuming B vitamins, leading them to conclude that supplementation is not recommended.
CAS Number454-29-5
2-Amino-4-mercaptobutyric acidChEBI
(S)-2-amino-4-mercapto-Butanoic acidHMDB
2-amino-4-mercapto-Butanoic acidHMDB
2-amino-4-mercapto-Butyric acidHMDB
2-amino-4-mercapto-DL-Butyric acidHMDB
2-amino-4-Sulfanylbutanoic acidHMDB
DL-2-amino-4-mercapto-Butyric acidHMDB
DL-2-amino-4-Mercaptobutyric acidHMDB
DL-Homocysteine (free base)HMDB
L-2-amino-4-mercapto-Butyric acidHMDB
Usaf b-12HMDB
Homocysteine, L isomerMeSH, HMDB
Homocysteine, L-isomerMeSH, HMDB
2 amino 4 Mercaptobutyric acidMeSH, HMDB
L-Isomer homocysteineMeSH, HMDB
(2S)-2-amino-4-sulfanylbutanoic acidbiospider
2 amino 4 mercaptobutyric acidbiospider
2-Amino-4-mercaptobutyric acid (VAN)biospider
2-amino-4-sulfanylbutanoic acidbiospider
Butanoic acid, 2-amino-4-mercapto-biospider
Butanoic acid, 2-amino-4-mercapto- (VAN)biospider
Butanoic acid, 2-amino-4-mercapto-, (S)-biospider
Butyric acid, 2-amino-4-mercapto-biospider
Butyric acid, 2-amino-4-mercapto-, DL-biospider
Butyric acid, 2-amino-4-mercapto-, DL- (9CI)biospider
Butyric acid, 2-amino-4-mercapto-, L-biospider
DL-2-Amino-4-mercaptobutyric acidbiospider
DL-homocysteine (free base)biospider
Homocysteine (van)biospider
Homocysteine, l isomerbiospider
Homocysteine, l-biospider
Homocysteine, l-isomerbiospider
l-2-amino-4-mercaptobutyric acidbiospider
L-isomer homocysteinebiospider
Predicted Properties
Water Solubility14.8 g/LALOGPS
pKa (Strongest Acidic)2.46ChemAxon
pKa (Strongest Basic)9.41ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count3ChemAxon
Polar Surface Area63.32 ŲChemAxon
Rotatable Bond Count3ChemAxon
Refractivity32.94 m³·mol⁻¹ChemAxon
Polarizability13.44 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterNoChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Chemical FormulaC4H9NO2S
IUPAC name2-amino-4-sulfanylbutanoic acid
InChI IdentifierInChI=1S/C4H9NO2S/c5-3(1-2-8)4(6)7/h3,8H,1-2,5H2,(H,6,7)
Average Molecular Weight135.185
Monoisotopic Molecular Weight135.035399227
Description Belongs to the class of organic compounds known as alpha amino acids. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon).
KingdomOrganic compounds
Super ClassOrganic acids and derivatives
ClassCarboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
Direct ParentAlpha amino acids
Alternative Parents
  • Alpha-amino acid
  • Thia fatty acid
  • Fatty acyl
  • Fatty acid
  • Amino acid
  • Alkylthiol
  • Carboxylic acid
  • Monocarboxylic acid or derivatives
  • Organic nitrogen compound
  • Hydrocarbon derivative
  • Primary amine
  • Organosulfur compound
  • Organooxygen compound
  • Organonitrogen compound
  • Organic oxide
  • Primary aliphatic amine
  • Organopnictogen compound
  • Carbonyl group
  • Amine
  • Organic oxygen compound
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External Descriptors
OntologyNo ontology term
Physico-Chemical Properties - Experimental
Physico-Chemical Properties - Experimental
Physical stateSolid
Physical DescriptionNot Available
Mass CompositionNot Available
Melting Point232-233 oC
Boiling PointNot Available
Experimental Water SolubilityNot Available
Experimental logPNot Available
Experimental pKa2.22
Isoelectric pointNot Available
Optical RotationNot Available
Spectroscopic UV DataNot Available
DensityNot Available
Refractive IndexNot Available
TypeDescriptionSplash KeyView
GC-MSL-Homocysteine, non-derivatized, GC-MS Spectrumsplash10-0059-0930000000-b4e6d47b81f1810f1f31Spectrum
GC-MSL-Homocysteine, non-derivatized, GC-MS Spectrumsplash10-004i-0910000000-7b3c5664e3b6b1930674Spectrum
GC-MSL-Homocysteine, non-derivatized, GC-MS Spectrumsplash10-004i-0910000000-0dbe4ce28b468fb874f0Spectrum
GC-MSL-Homocysteine, 3 TMS, GC-MS Spectrumsplash10-00di-9730000000-952f5d413ee77e474820Spectrum
GC-MSL-Homocysteine, 2 TMS, GC-MS Spectrumsplash10-03yi-3900000000-b5bcb65d1cfa2f5b4a83Spectrum
GC-MSL-Homocysteine, 3 TMS, GC-MS Spectrumsplash10-0059-1950000000-09d1f6d02198624082eaSpectrum
GC-MSL-Homocysteine, non-derivatized, GC-MS Spectrumsplash10-0059-0981000000-c6d399e1bddf1f7bc057Spectrum
GC-MSL-Homocysteine, non-derivatized, GC-MS Spectrumsplash10-0059-0930000000-b4e6d47b81f1810f1f31Spectrum
GC-MSL-Homocysteine, non-derivatized, GC-MS Spectrumsplash10-00di-9730000000-952f5d413ee77e474820Spectrum
GC-MSL-Homocysteine, non-derivatized, GC-MS Spectrumsplash10-03yi-3900000000-b5bcb65d1cfa2f5b4a83Spectrum
GC-MSL-Homocysteine, non-derivatized, GC-MS Spectrumsplash10-0059-1950000000-09d1f6d02198624082eaSpectrum
Predicted GC-MSL-Homocysteine, non-derivatized, Predicted GC-MS Spectrum - 70eV, Positivesplash10-0006-9000000000-1f800d28bca4b2b7a49fSpectrum
Predicted GC-MSL-Homocysteine, 1 TMS, Predicted GC-MS Spectrum - 70eV, Positivesplash10-00dj-9700000000-368cb861e20b107da57aSpectrum
TypeDescriptionSplash KeyView
MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, Positive (Annotated)splash10-0006-9300000000-a8fd35730e901755194e2012-07-24View Spectrum
MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, Positive (Annotated)splash10-0a4l-9000000000-0e79cc37f5cb8f05cd372012-07-24View Spectrum
MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, Positive (Annotated)splash10-052b-9000000000-694b412a6bed9a77958e2012-07-24View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-000f-9700000000-2e1b7e55ed5da543b5572016-09-12View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0006-9100000000-7e82906cac0f17bd51232016-09-12View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0bvi-9000000000-7c49d870f77950b940a52016-09-12View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-001i-3900000000-4e1b7a42d769b9c2574c2016-09-12View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-001i-7900000000-35b3c5fd78dec88148fb2016-09-12View Spectrum
Predicted MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-001i-9000000000-533b0cacf1e578850e942016-09-12View Spectrum
1D NMR1H NMR Spectrum (1D, 500 MHz, H2O, experimental)Spectrum
1D NMR1H NMR Spectrum (1D, 400 MHz, D2O, experimental)Spectrum
1D NMR1H NMR Spectrum (1D, D2O, experimental)Spectrum
1D NMR13C NMR Spectrum (1D, D2O, experimental)Spectrum
1D NMR13C NMR Spectrum (1D, 100 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 100 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 1000 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 1000 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 200 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 200 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 300 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 300 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 400 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 400 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 500 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 500 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 600 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 600 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 700 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 700 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 800 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 800 MHz, H2O, predicted)Spectrum
1D NMR13C NMR Spectrum (1D, 900 MHz, H2O, predicted)Spectrum
1D NMR1H NMR Spectrum (1D, 900 MHz, H2O, predicted)Spectrum
2D NMR[1H, 13C]-HSQC NMR Spectrum (2D, 600 MHz, H2O, experimental)Spectrum
ChemSpider ID757
KEGG Compound IDC05330
Pubchem Compound ID778
Pubchem Substance IDNot Available
ChEBI ID17230
Phenol-Explorer IDNot Available
DrugBank IDNot Available
CRC / DFC (Dictionary of Food Compounds) IDNot Available
EAFUS IDNot Available
BIGG ID45588
KNApSAcK IDC00001365
HET IDNot Available
Food Biomarker OntologyNot Available
VMH IDNot Available
Flavornet IDNot Available
GoodScent IDNot Available
SuperScent IDNot Available
Wikipedia IDHomocysteine
Phenol-Explorer Metabolite IDNot Available
Duplicate IDSNot Available
Old DFC IDSNot Available
Associated Foods
FoodContent Range AverageReference
Biological Effects and Interactions
Health Effects / Bioactivities
EnzymesNot Available
Betaine MetabolismSMP00123 map00260
Catecholamine BiosynthesisSMP00012 map00350
Glycine and Serine MetabolismSMP00004 map00260
Homocysteine DegradationSMP00455 Not Available
Methionine MetabolismSMP00033 map00270
MetabolismNot Available
BiosynthesisNot Available
Organoleptic Properties
FlavoursNot Available
Synthesis ReferenceNot Available
General ReferenceNot Available
Content Reference— Duke, James. 'Dr. Duke's Phytochemical and Ethnobotanical Databases. United States Department of Agriculture.' Agricultural Research Service, Accessed April 27 (2004).
— Shinbo, Y., et al. 'KNApSAcK: a comprehensive species-metabolite relationship database.' Plant Metabolomics. Springer Berlin Heidelberg, 2006. 165-181.