L-Methionin Chemische Eigenschaften,Einsatz,Produktion Methoden
R-S?tze Betriebsanweisung:
R33:Gefahr kumulativer Wirkungen.
S-S?tze Betriebsanweisung:
S24/25:Berührung mit den Augen und der Haut vermeiden.
Beschreibung
Colorless or white lustrous plates, or a white crystalline powder.
It has a slight, characteristic odor. It is soluble in water, in alkali
solutions, and in dilute mineral acids. It is slightly soluble in
alcohol and practically insoluble in ether.
Verwenden
L-Methionine is used as an essential amino acid for human development and therapeutically acts as an antidote for acetaminophen poisoning. It serves as a chelating agent for heavy metals, as a flavoring agent and nutritional supplement for foods. It acts as a feed additive, vegetable oil enrichment and as a single cell protein. In addition to this, it is used as a hepatoprotectant and also acts as a lipotropic agent and prevents excess fat buildup in the liver.
Vorbereitung Methode
Numerous methods have been described for manufacture of
methionine, including hydrolysis of methionine amide )and 5-(bmethylmercaptoethyl)-
hydantoin.
synthetische
The production method of choice for L-methionine is still the enzymatic resolution of racemic N-acetyl-methionine using acylase from Aspergillus oryzae. The production is carried out in a continuously operated fixed-bed or enzyme membrane reactor.
Definition
ChEBI: 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.
Allgemeine Beschreibung
Minute hexagonal plates from dilute alcohol.
Air & Water Reaktionen
Reacts with water, steam, and/or acids to produce toxic and flammable vapors of hydrogen sulfide . Water soluble . pH of 1% aqueous solution is 5.6-6.0.
Reaktivit?t anzeigen
An organosulfide and amine derivative, carboxylic acid. Look at Reactive Groups 20 (organosulfides), 7 (amines), and 3 (carboxylic acids) may give indications about reactive tendencies. L-Methionine is an amino acid essential in human nutrition.
Health Hazard
ACUTE/CHRONIC HAZARDS: L-Methionine is dangerous when heated to decomposition; it emits dangerous and highly toxic fumes.
Brandgefahr
Flash point data for L-Methionine is not available, but L-Methionine is probably combustible.
Pharmazeutische Anwendungen
Methionine is used in oral pharmaceutical formulations as a
flavoring agent.It has been included in parenteral formulations as
a pH controlling agent,and it has also been used experimentally
as an antioxidant with antibodies.Methionine is also used
therapeutically in oral tablets
Sicherheitsprofil
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 NOx and SOx.
Sicherheit(Safety)
Methionine is used in oral pharmaceutical formulations. The pure
form of methionine is mildly toxic by ingestion and by the IP route.
LD
50 (rat, IP): 4.328 g/k
LD
50 (rat, oral): 36 g/kg
Lager
Methionine is sensitive to light and should be stored in a cool, dark
place.
l?uterung methode
Crystallise L-methionine from aqueous EtOH. Also purify it by dissolving ~0.5g of amino acid in ~10mL of hot H2O, filtering, adjusting the pH to 5.8 with 5N HCl, collecting the solid after addition of ~20mL of EtOH. It is recrystallised by dissolving in H2O and adding EtOH. It sublimes at 197-208o/0.3mm with 99.8% recovery and unracemised [Gross & Gradsky J Am Chem Soc 77 1678 1955]. [Milne & Peng J Am Chem Soc 79 647 1957, Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 pp 2125-2152 1961, Beilstein 4 IV 3189.]
Inkompatibilit?ten
Methionine is incompatible with strong oxidizing agents.
Regulatory Status
Included in the FDA Inactive Ingredients Database (oral tablets).
Included in parenteral preparations (injection solutions; powders
for reconstitution) licensed in the UK.
L-Methionin Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
