L-Methionine

Description

L-Methionine is identified by CAS 63-68-3, molecular formula C5H11NO2S and molecular weight 149.05 g/mol. UNII AE28F7PNPL; ChEBI 16643; InChIKey FFEARJCKVFRZRR-BYPYZUCNSA-N. Boiling Point: 181 °C (decomposes); Melting Point: 283; Melting Point: 284 °C.

Identification

CAS Registry Number	63-68-3
PubChem CID	6137
Molecular formula	C5H11NO2S
Molecular weight	149.05 g/mol
IUPAC name	(2S)-2-amino-4-methylsulfanylbutanoic acid
InChIKey	FFEARJCKVFRZRR-BYPYZUCNSA-N
UNII (FDA)	AE28F7PNPL
ChEBI ID	CHEBI:16643
ATC code (WHO)	V03AB26

Computed Descriptors

Molecular Weight	149.21
XLogP3	-1.9
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	4
Exact Mass	149.05104977
Monoisotopic Mass	149.05104977
Topological Polar Surface Area	88.6
Heavy Atom Count	9
Formal Charge	0

Physical & Chemical Properties

Boiling Point	181 °C (decomposes)
Melting Point	283
Melting Point	284 °C
Solubility	56600
Solubility	In water, 56.6 g/L at 25 °C
Solubility	56.6 mg/mL
Vapor Pressure	0.00000052 [mmHg]
LogP	-1.87
LogP	log Kow = -1.87
Ionization Efficiency	2.7

Physical description & handling notes

• Minute hexagonal plates from dilute alcohol. (NTP, 1992)
• Solid; [Merck Index] Colorless or white solid with a faint odor; [HSDB] White powder; [Sigma-Aldrich MSDS]
• Solid
• Minute hexagonal plates from dilute alcohol
• Colorless or white, lustrous plates or as white, crystalline powder
• Faint

Regulatory Status

Regulatory & Food Contact	EU Flavoring substances FDA Substance added to food: FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, NUTRIENT SUPPLEMENT Flavoring Agents CIR / INCI: Cosmetic ingredients (Methionine) -> CIR (Cosmetic Ingredient Review) CIR / INCI: Skin conditioning; Antistatic; Hair conditioning
GHS notification summary	97.6% (206 / 211)

GHS Hazard Classification

GHS notification summary	97.6% (206 / 211)

Documented Uses

• Farming (Feed Additives) [Category: Industry]
• Feed additive; vegetable oil enrichment; single-cell protein /DL-Methionine/
• BIOLOGICAL ACTIVITIES: Anticataract; antidote (acteaminophen, paracetamol); antieczemic; antihepatotic; antioxidant; antiparkinsonian; cancer-preventive; emetic; essential; glutathionigenic; heptoprotective; lioptropic; urine-acidifier, urine-deodorant
• THERAPEUTIC CATEGORY: Hepatoprotectant; antidote (acetaminophen poisoning); urinary acidifier
• For more Uses (Complete) data for (L)-Methionine (6 total), please visit the HSDB record page.
• Use (kg; approx.) in Germany (2009): >25000

Synonyms

L-methionine; 63-68-3; methionine; h-Met-oh; (S)-2-Amino-4-(methylthio)butanoic acid; Cymethion; L-(-)-Methionine; S-Methionine; L-Methioninum; Neo-methidin; Methilanin; (S)-methionine; (L)-Methionine; metionina; Acimethin; L-Methionin

Frequently Asked Questions

What are the CAS number and molecular formula of L-Methionine?

CAS 63-68-3; molecular formula C5H11NO2S; molecular weight 149.05 g/mol.

What other names is L-Methionine known by?

L-methionine, 63-68-3, methionine, h-Met-oh, (S)-2-Amino-4-(methylthio)butanoic acid, Cymethion.

What is the regulatory status of L-Methionine?

Documented regulatory listings: EU Flavoring substances; FDA Substance added to food: FLAVOR ENHANCER, FLAVORING AGENT OR ADJUVANT, NUTRIENT SUPPLEMENT; Flavoring Agents.

Is L-Methionine classified as hazardous?

97.6% of GHS notifications report no hazard classification (206 of 211).

What are the key physical properties of L-Methionine?

Boiling Point: 181 °C (decomposes); Melting Point: 283; Melting Point: 284 °C; Solubility: 56600.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.