- Mol File:63-68-3.mol
- 融点 284 °C (dec.)(lit.)
- 比旋光度 23.25 º (c=2, 6N HCl)
- 沸点 393.91°C (estimate)
- 比重(密度) 1,34g/cm
- 屈折率 1.5216 (estimate)
- 貯蔵温度 Store at RT.
- 溶解性1 M HCl: 0.5 M at 20 °C, clear, colorless
- 外見 Solid
- 酸解離定数(Pka)2.13(at 25℃)
- PH5-7 (10g/l, H2O, 20℃)
- 光学活性 (optical activity)[α]20/D +23.7±0.5°, c = 5% in 5 M HCl
- 水溶解度 Soluble
- 極大吸収波長 (λmax)λ: 260 nm Amax: 0.40
λ: 280 nm Amax: 0.05
- Merck 14,5975
- BRN 1722294
- 安定性：Stable. Incompatible with strong oxidizing agents.
- CAS データベース63-68-3(CAS DataBase Reference)
- EPAの化学物質情報L-Methionine (63-68-3)
- 外観白色, 結晶～結晶性粉末
- 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。
- 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.
- OriginatorMeonine ,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 ProcessA 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 FunctionLipotropic
- Synthesis Reference(s)Canadian Journal of Chemistry, 47, p. 3271, 1969 DOI: 10.1139/v69-542
Organic Syntheses, Coll. Vol. 2, p. 384, 1943
Synthetic Communications, 26, p. 3619, 1996
- 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.
LD50 (rat, IP): 4.328 g/k
LD50 (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.
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