L-Methionine

Molecular Structure:

Molecular Formula: C₅H₁₁NO₂S
Molecular Weight: 149.21
IUPAC Name: (2S)-2-Amino-4-methylsulfanylbutanoic acid
Synonyms of L-Methionine (CAS NO.63-68-3): (S)-2-Amino-4-(methylthio)butanoic acid ; 2-Amino-4-(methylthio)butyric acid, (S)- ; L(-)-Amino-gamma-methylthiobutyric acid ; L-(-)-Methionine ; Methioninum
CAS NO: 63-68-3
EINECS: 200-562-9
H bond acceptors: 3
H bond donors: 3
Freely Rotating Bonds: 5
Polar Surface Area: 54.84 Å²
Index of Refraction: 1.53
Molar Refractivity: 38.26 cm³
Molar Volume: 123.7 cm³
Surface Tension: 50.5 dyne/cm
Density: 1.206 g/cm³
Flash Point: 139.4 °C
Enthalpy of Vaporization: 60.21 kJ/mol
Boiling Point: 306.9 °C at 760 mmHg
Vapour Pressure: 0.00017 mmHg at 25°C
Melting point: 276-279 °C (dec.)
Alpha: 23.25 º (c=2, 6N HCl)
Water solubility: Soluble
Storage temp: Store at RT.
Stability: Stable. Incompatible with strong oxidizing agents.
Appearance: White crystalline powder
Product Categories of L-Methionine (CAS NO.63-68-3): Amino Acids;Amino Acid Derivatives;Methionine [Met, M];Amino Acids and Derivatives;Amino Acids;Chiral Compound;Miscellaneous Compounds

 L-Methionine (CAS NO.63-68-3) is used as an intermediate in the biosynthesis of cysteine, carnitine, taurine, lecithin, phosphatidylcholine, and other phospholipids. It is also used by plants for synthesis of ethylene,the process of which is known as the Yang Cycle or the Methionine cycle.

 L-Methionine (CAS NO.63-68-3) is synthesized via a pathway that uses both aspartic acid and cysteine in plants and microorganisms,. Firstly, Aspartic acid is converted via β-Aspartyl-semialdehyde into Homoserine, introducing the pair of contiguous methylene groups. Then Homoserine converts to O-succinyl homoserine, which reacts with cysteine to produce cystathionine, which is cleaved to yield homocysteine. Subsequent methylation of the thiol group by folates affords methionine. Both cystathionine-γ-synthase and cystathionine-β-lyase require Pyridoxyl-5'-phosphate as a cofactor, whereas homocysteine methyltransferase requires Vitamin B12 as a cofactor.

 

Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program.

Risk Statements: 33
R33:Danger of cumulative effects. 
Safety Statements: 24/25
S24/25: Avoid contact with skin and eyes.
WGK Germany: 2
RTECS: PD0457000
F: 10-23
HS Code: 29304010
Mildly toxic by ingestion and intraperitoneal routes. Human mutation data reported. An experimental teratogen. Experimental reproductive effects. An essential sulfur-containing amino acid. When heated to decomposition it emits very toxic fumes of NO_x and SO_x.

General Information: As in any fire, wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Dusts at sufficient concentrations can form explosive mixtures with air.
Extinguishing Media: For small fires, use water spray, dry chemical, carbon dioxide or chemical foam. 
Handling: Minimize dust generation and accumulation. Avoid breathing dust, vapor, mist, or gas. Avoid contact with skin and eyes.
Storage: Store in a cool, dry place. Store in a tightly closed container. Keep refrigerated. (Store below 4°C/39°F.)