FComEx: L-Homocysteine (PC000425)

Record Information

Version

1.0

Creation date

2015-10-09 22:30:38 UTC

Update date

2017-01-19 02:36:23 UTC

FoodComEx ID

PC000425

FoodDB Record

FDB001491

Chemical Information

Name

L-Homocysteine

Description

A 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 Number

454-29-5

Structure

MOL SDF PDB SMILES InChI

Synonyms

Synonym	Source
(+-)-homocysteine	biospider
(2S)-2-amino-4-sulfanylbutanoic acid	biospider
(S)-2-amino-4-mercapto-Butanoate	biospider
(S)-2-amino-4-mercapto-Butanoic acid	biospider
2 amino 4 mercaptobutyric acid	biospider
2-amino-4-mercapto-Butanoate	biospider
2-amino-4-mercapto-Butanoic acid	biospider
2-amino-4-mercapto-Butyric acid	biospider
2-amino-4-mercapto-DL-Butyrate	biospider
2-amino-4-mercapto-DL-Butyric acid	biospider
2-amino-4-Mercaptobutyrate	Generator
2-Amino-4-mercaptobutyric acid	biospider
2-Amino-4-mercaptobutyric acid (VAN)	biospider
2-amino-4-sulfanylbutanoate	biospider
2-amino-4-sulfanylbutanoic acid	biospider
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
D,l-homocysteine	biospider
DL-2-amino-4-mercapto-Butyric acid	biospider
DL-2-Amino-4-mercaptobutyric acid	biospider
DL-homocysteine	biospider
DL-homocysteine (free base)	biospider
Hcy	ChEBI
Homo-CYS	biospider
Homocysteine	biospider
Homocysteine (van)	biospider
Homocysteine, l isomer	biospider
Homocysteine, l-	biospider
Homocysteine, l-isomer	biospider
L-2-amino-4-mercapto-Butyric acid	biospider
l-2-amino-4-mercaptobutyric acid	biospider
L-isomer homocysteine	biospider
Usaf b-12	HMDB

Chemical Formula

C4H9NO2S

IUPAC name

2-amino-4-sulfanylbutanoic acid

InChI Identifier

InChI=1S/C4H9NO2S/c5-3(1-2-8)4(6)7/h3,8H,1-2,5H2,(H,6,7)

InChI Key

FFFHZYDWPBMWHY-UHFFFAOYSA-N

Isomeric SMILES

NC(CCS)C(O)=O

Average Molecular Weight

135.185

Monoisotopic Molecular Weight

135.035399227

Chemical Taxonomy

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).

Kingdom

Organic compounds

Super Class

Organic acids and derivatives

Class

Carboxylic acids and derivatives

Sub Class

Amino acids, peptides, and analogues

Direct Parent

Alpha amino acids

Alternative Parents