L-メチオニン 化学特性,用途語,生産方法
外観
白色, 結晶～結晶性粉末
定義
本品は、次の化学式で表されるアミノ酸である。
溶解性
水100gに3g (0℃), 5.6g (30℃)溶解。有機溶媒に不溶。酸, アルカリ溶液に可溶。水にやや溶けやすく、エタノールに極めて溶けにくく、ジエチルエーテルにほとんど溶けない。塩酸又は水酸化ナトリウム溶液に溶ける。
化粧品の成分用途
ヘアコンディショニング剤、皮膚コンディショニング剤
効能
解毒薬
説明
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.
化学的特性
White crystalline powder
化学的特性
Methionine occurs as a white or almost white, crystalline powder or
colorless crystals.
Originator
Meonine ,Ives,US,1944
使用
methionine is slows down and normalizes oil gland sebum production. Methionine is also used as a texturizer in cosmetic creams. It is an essential amino acid found in a number of proteins and obtained by means of fermentation.
使用
Essential aminoacid for human development. Hepatoprotectant; antidote (acetominophen poisoning); urinary acidifier.
定義
ChEBI: The L-enantiomer of methionine.
調製方法
Numerous methods have been described for manufacture of
methionine, including hydrolysis of methionine amide )and 5-(bmethylmercaptoethyl)-
hydantoin.
Manufacturing Process
A 3-necked flask fitted with a stirrer, thermometer, gas inlet, dropping funnel, and brine-cooled reflux condenser was charged with 53 g (1.1 mol) methyl mercaptan and 0.35 g mercuric methyl mercaptide. After admitting 56 g (1.0mol) of acrolein during the course of 15 minutes with an inside temperature of
about 10°C, the temperature was allowed to rise spontaneously to 75°C, at
which point an ice bath was applied. There was no indication of further
reaction one hour after the addition of the acrolein. Distillation of the product
gave 71 g (yield 68%) of β-methylmercaptopropionaldehyde, as described in
US Patent 2,584,496.
Then as described in US Patent 2,732,400, β-methylmercaptopropionaldehyde
(0.60 M) (56.5 g) is added to a stirred solution of sodium cyanide (0.66 M)
(32.4 g) and ammonium chloride (0.63 M) (33.7 g) in water (140 ml). The
temperature of the mixture rises to 49°C and is maintained at this point by
heat evolution for about 5 minutes when it slowly begins to fall. Methanol (50
ml) is added and the mixture is stirred for 4 hours as the temperature falls to
28°C (room temperature).
After chilling to +12°C, additional methanol (35 ml) and a concentrated
aqueous ammoniun hydroxide solution (1.4 M) (100 ml) are added and
stirring is continued for 2 hours at a temperature maintained at from +5° to
+15°C. The organic layer is separated and solvent is stripped from the
aqueous layer at water aspirator pressure at a temperature below 40°C. The
residue is extracted several times with chloroform and the chloroform extracts
are combined with the separated oil. Chloroform is removed at water aspirator
pressure at a temperature below 35°C to leave crude α-amino-γmethylmercaptobutyronitrile (methionine nitrile) in 88% yield (68 g) as a
clear, somewhat viscous oil.
The methionine nitrile (20 g) is dissolved in a solution prepared from 50 ml of
aqueous 5 N sodium hydroxide solution and 65 ml of ethanol. The solution is
then refluxed for 24 hours; ammonia is evolved. The solution is treated with
activated carbon, filtered, acidified with glacial acetic acid (17 ml), chilled to -
10°C and filtered to give crude product. This crude product is then slurried
with a solution made up of 20 ml of water and 20 ml of methanol, filtered at -
5° to +10°C and dried to give dl-methionine as white platelets.
Therapeutic Function
Lipotropic
Synthesis Reference(s)
Canadian Journal of Chemistry, 47, p. 3271, 1969
DOI: 10.1139/v69-542Synthetic Communications, 26, p. 3619, 1996
DOI: 10.1080/00397919608003774
一般的な説明
Minute hexagonal plates from dilute alcohol.
空気と水の反応
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.
反応プロフィール
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.
健康ハザード
ACUTE/CHRONIC HAZARDS: L-Methionine is dangerous when heated to decomposition; it emits dangerous and highly toxic fumes.
火災危険
Flash point data for L-Methionine is not available, but L-Methionine is probably combustible.
応用例（製薬）
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
安全性プロファイル
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.
安全性
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
貯蔵
Methionine is sensitive to light and should be stored in a cool, dark
place.
純化方法
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.]
不和合性
Methionine is incompatible with strong oxidizing agents.
規制状況(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-メチオニン 上流と下流の製品情報
原材料
準備製品
