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Catalog No. DB00134 Name DrugBank
CAS Number 63-68-3 Website http://www.ualberta.ca/
M. F. C5H11NO2S Telephone (780) 492-3111
M. W. 149.21134 Fax (780) 492-1071
Purity Email david.wishart@ualberta.ca
Storage Chembase ID: 20


IUPAC name
(2S)-2-amino-4-(methylsulfanyl)butanoic acid
IUPAC Traditional name
Brand Name
2-Amino-4-(methylthio)butyric acid
a-Amino-g-methylmercaptobutyric acid
(S)-2-Amino-4-(methylthio)butanoic acid
g-Methylthio-a-aminobutyric acid
L-a-Amino-g-methylthiobutyric acid


PubChem CID 6137
CAS Number 63-68-3
PubChem SID 46505750


Hydrophobicity(logP) -1.9
Solubility 56.6 mg/mL at 25 oC [YALKOWSKY,SH & DANNENFELSER,RM (1992)]


Description (English)
Item Information
Drug Groups approved; nutraceutical
Description A sulfur containing essential amino acid that is important in many body functions. It is a chelating agent for heavy metals. [PubChem]
Indication Used for protein synthesis including the formation of SAMe, L-homocysteine, L-cysteine, taurine, and sulfate.
Pharmacology L-Methionine is a principle supplier of sulfur which prevents disorders of the hair, skin and nails; helps lower cholesterol levels by increasing the liver's production of lecithin; reduces liver fat and protects the kidneys; a natural chelating agent for heavy metals; regulates the formation of ammonia and creates ammonia-free urine which reduces bladder irritation; influences hair follicles and promotes hair growth. L-methionine may protect against the toxic effects of hepatotoxins, such as acetaminophen. Methionine may have antioxidant activity.
Toxicity Doses of L-methionine of up to 250 mg daily are generally well tolerated. Higher doses may cause nausea, vomiting and headache. Healthy adults taking 8 grams of L-methionine daily for four days were found to have reduced serum folate levels and leucocytosis. Healthy adults taking 13.9 grams of L-methionine daily for five days were found to have changes in serum pH and potassium and increased urinary calcium excretion. Schizophrenic patients given 10 to 20 grams of L-methionine daily for two weeks developed functional psychoses. Single doses of 8 grams precipitated encephalopathy in patients with cirrhosis.
Affected Organisms
Humans and other mammals
Biotransformation Hepatic
Absorption Absorbed from the lumen of the small intestine into the enterocytes by an active transport process.
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