*This document is like a lab demo—an example Certificate of Analysis (COA) that showcases what a COA looks like but may not match the latest batch in all its glory. Think of it as a chemistry experiment: close, but not quite the final reaction!
L-methionine is the L-enantiomer of methionine. It has a role as a nutraceutical, a micronutrient, an antidote to paracetamol poisoning, a human metabolite and a mouse metabolite. It is an aspartate family amino acid, a proteinogenic amino acid, a methionine and a L-alpha-amino acid. It is a conjugate base of a L-methioninium. It is a conjugate acid of a L-methioninate. It is an enantiomer of a D-methionine. It is a tautomer of a L-methionine zwitterion.
A sulfur containing essential amino acid that is important in many body functions. It is a chelating agent for heavy metals.
L-Methionine is a metabolite found in or produced by Escherichia coli .
Methionine is a natural product found in Pinus densiflora, Cyperus aromaticus, and other organisms with data available.
Methionine is one of nine essential amino acids in humans , Methionine is required for growth and tissue repair. A sulphur-containing amino acid, methionine improves the tone and pliability of skin, hair, and strengthens nails. Involved in many detoxifying processes, sulphur provided by methionine protects cells from pollutants, slows cell aging, and is essential for absorption and bio-availability of selenium and zinc. Methionine chelates heavy metals, such as lead and mercury, aiding their excretion. It also acts as a lipotropic agent and prevents excess fat buildup in the liver.
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Methionine is a dietary indispensable amino acid required for normal growth and development of humans, other mammals, and avian species. In addition to being a substrate for protein synthesis, it is an intermediate in transmethylation reactions, serving as the major methyl group donor in vivo, including the methyl groups for DNA and RNA intermediates. Methionine is a methyl acceptor for 5-methyltetrahydrofolate-homocysteine methyl transferase , the only reaction that allows for the recycling of this form of folate, and is also a methyl acceptor for the catabolism of betaine. Methionine is also required for synthesis of cysteine. Methionine is accepted as the metabolic precursor for cysteine. Only the sulfur atom from methionine is transferred to cysteine; the carbon skeleton of cysteine is donated by serine. The adequacy range of dietary requirements of specific amino acids in disease states is difficult to determine. Requirements may not be similar in disease with regard to protein synthesis. Requirements for this purpose can be assessed only when such a function can be measured and related to clinical outcome. There is apparent consensus concerning normal sulfur amino acid requirements. WHO recommendations amount to 13 mg/kg per 24 h in healthy adults. This amount is roughly doubled in artificial nutrition regimens. In disease or after trauma, requirements may be altered for methionine, cysteine, and taurine. Although in specific cases of congenital enzyme deficiency, prematurity, or diminished liver function, hypermethionemia or hyperhomocysteinemia may occur, SAA supplementation can be considered safe in amounts exceeding 2-3 times the minimal recommended daily intake. Apart from some very specific indications the usefulness of SAA supplementation is not yet established. Methionine is known to exacerbate psychopathological symptoms in schizophrenic patients, there is no evidence of similar effects in healthy subjects. The role of methionine as a precursor of homocysteine is the most notable cause for concern. A loading dose of methionine has been given, and the resultant acute increase in plasma homocysteine has been used as an index of the susceptibility to cardiovascular disease. Although this procedure results in vascular dysfunction, this is acute and unlikely to result in permanent damage. However, a 10-fold larger dose, given mistakenly, resulted in death. Longer-term studies in adults have indicated no adverse consequences of moderate fluctuations in dietary methionine intake, but intakes higher than 5 times normal resulted in elevated homocysteine levels. These effects of methionine on homocysteine and vascular function are moderated by supplements of vitamins B-6, B-12, C, and folic acid. In infants, methionine intakes of 2 to 5 times normal resulted in impaired growth and extremely high plasma methionine levels, but no adverse long-term consequences were observed. . It is a chelating agent for heavy metals.
A sulfur-containing essential L-amino acid that is important in many body functions.
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Computed Properties
Molecular Weight:
149.21 g/mol
XLogP3:
-1.9
Hydrogen Bond Donor Count:
2
Hydrogen Bond Acceptor Count:
4
Rotatable Bond Count:
4
Exact Mass:
149.05104977 g/mol
Monoisotopic Mass:
149.05104977 g/mol
Topological Polar Surface Area:
88.6 Ų
Heavy Atom Count:
9
Formal Charge:
0
Complexity:
97
Isotope Atom Count:
0
Defined Atom Stereocenter Count:
1
Undefined Atom Stereocenter Count:
0
Defined Bond Stereocenter Count:
0
Undefined Bond Stereocenter Count:
0
Covalently-Bonded Unit Count:
1
Compound Is Canonicalized:
Yes
hazard signal
hazard classes and categories
Not Classified
hazard statements
Not Classified
Reported as not meeting GHS hazard criteria by 206 of 211 companies (only ~ 2.4% companies provided GHS information). For more detailed information, please visit ECHA C&L website.
hazards summary
Reacts with water evolving hydrogen sulfide (toxic and flammable). May cause irritation. See Hydrogen sulfide.
toxicity summary
The mechanism of the possible anti-hepatotoxic activity of L-methionine is not entirely clear. It is thought that metabolism of high doses of acetaminophen in the liver lead to decreased levels of hepatic glutathione and increased oxidative stress. L-methionine is a precursor to L-cysteine. L-cysteine itself may have antioxidant activity. L-cysteine is also a precursor to the antioxidant glutathione. Antioxidant activity of L-methionine and metabolites of L-methionine appear to account for its possible anti-hepatotoxic activity. Recent research suggests that methionine itself has free-radical scavenging activity by virtue of its sulfur, as well as its chelating ability.
symptoms
health effects
Chronically high levels of methionine are associated with at least 7 inborn errors of metabolism including: Cystathionine Beta-Synthase Deficiency, Glycine N-methyltransferase Deficiency, Homocystinuria-megaloblastic anemia due to defect in cobalamin metabolism, Methionine Adenosyltransferase Deficiency, Methylenetetrahydrofolate reductase deficiency and S-Adenosylhomocysteine Hydrolase Deficiency.
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