• Name

  L-Methionine

• EINECS 200-562-9
• CAS No. 63-68-3
• Article Data180
• CAS DataBase
• Density 1.206 g/cm³
• Solubility Soluble in water
• Melting Point 284 °C (dec.)(lit.)
• Formula C₅H₁₁NO₂S
• Boiling Point 306.9 °C at 760 mmHg
• Molecular Weight 149.214
• Flash Point 139.4 °C
• Transport Information
• Appearance White crystalline powder
• Safety 24/25
• Risk Codes 33
• Molecular Structure
• Hazard Symbols
• Synonyms 2-Amino-4-methylthiobutanoic acid (S)-;L-Methionine,;Methionine, L-;2-Amino-4-(methylthio)butyric acid, (S)-;L-Homocysteine, S-methyl-;L-Methionin;L-alpha-Amino-gamma-methylthiobutyric acid;(2S)-2-amino-4-(methylsulfanyl)butanoic acid;L-Methionine (AJI92;USP24);Methionine, L- (8CI);L-Methioninum;Methionine (VAN);(L)-Methionine;(S)-methionine;L-2-Amino-4methylthiobutyric acid;S-Methyl-L-homocysteine;(S)-2-amino-4-(methylthio)butyric acid;Methioninum [INN-Latin];2-Amino-4-methylthiobutanoic acid;Acimethin;
• PSA 88.62000
• LogP 0.85170

Synthetic route

2488-17-7, 3913-77-7, 57496-45-4, 81444-65-7, 81444-66-8, 81444-67-9, 34805-21-5

Boc-Met(O)-OH

63-68-3

L-methionine

Conditions

Conditions	Yield
With dimethylsulfide; hydrogen fluoride at 0℃; for 2h; Product distribution;	100%

13253-44-6

5-[2-(methylthio)ethyl]imidazolidine-2,4-dione

A

63-68-3

L-methionine

B

54896-74-1

(S)-N-carbamoylmethionine

Conditions

Conditions	Yield
In water at 30℃; for 72h; Mechanism; Pseudomonas sp. strain NS671, air. pH 7.0 - 7.2; different cultivation times, other 5-substituted hydantoins;	A 98% B n/a
With sodium hydroxide; air at 30℃; for 72h; Pseudomonas sp. Strain NS671;	A 93% B n/a
at 40℃; Product distribution; Mechanism; conversion by Pseudomonas sp. strain NS671;

2488-15-5

N-tert-butoxycarbonyl-L-methionine

63-68-3

L-methionine

Conditions

Conditions	Yield
With water at 170℃; for 0.05h; Microwave irradiation;	98%
With tetradecyl(trihexyl)phosphonium bistriflamide; trifluoroacetic acid at 130℃; for 0.166667h; Ionic liquid;	97%
With trifluoroacetic acid at 20℃; for 0.25h;

54896-74-1

(S)-N-carbamoylmethionine

63-68-3

L-methionine

Conditions

Conditions	Yield
With NH4Cl-NH4OH buffer pH 8.5; nickel dichloride at 60℃; for 24h; N-carbamyl-L-amino acid aminohydrolase;	97%
With Tris-HCl buffer; N-carbamoyl-L-amino acid hydrolase; iron(II) sulfate at 30℃; for 2h;
With potassium phosphate buffer; Pseudomonas sp. AJ-11220 In various solvent(s) at 30℃; for 1h;

(S)-4'-(2-(methylthio)ethyl)-9λ4-boraspiro[bicyclo[3.3.1]nonane-9,2'-[1,3,2]oxazaborolidin]-5'-one

63-68-3

L-methionine

Conditions

Conditions	Yield
With tetrabutyl ammonium fluoride In tetrahydrofuran; water at 20℃; for 1h;	96%

59-51-8

DL-methionine

63-68-3

L-methionine

Conditions

Conditions	Yield
In water at 37℃; for 10h; NADH, ammonium chloride, sodium formate, D-amino acid oxidase, catalase, leucine dehydrogenase, formate dehydrogenase, Tris-HCl buffer, pH 8.5;	95%
With D-amino acid oxidase; E. coli branched-chain amino acid aminotransferase In water at 37℃; for 24h; Tris buffer, pH 8.5, 1mM EDTA, monosodium glutamate, bovine serum albumin, catalase, pyridoxal 5'-phosphate;	90%
Stage #1: DL-methionine In water at 0.99℃; for 96h; Stage #2: In water at 59.99℃; Purification / work up;	33%

90508-21-7

(S)-2-[{(allyloxy)carbonyl}amino]-4-(methylthio)butanoic acid

63-68-3

L-methionine

Conditions

Conditions	Yield
With tri-n-butyl-tin hydride; bis-triphenylphosphine-palladium(II) chloride In dichloromethane Ambient temperature;	95%

71989-28-1

N-[(9H-fluoren-9-ylmethoxy)carbonyl]-L-methionine

63-68-3

L-methionine

Conditions

Conditions	Yield
With sodium azide In N,N-dimethyl-formamide at 50℃; for 16h;	95%

73285-38-8

Z(OM4e)-Met(O)-OH

63-68-3

L-methionine

Conditions

Conditions	Yield
With trimethylsilyl bromide; methyl-phenyl-thioether In trifluoroacetic acid at 0℃; for 1h;	91.3%
With trimethylsilyl trifluoromethanesulfonate; methyl-phenyl-thioether In trifluoroacetic acid at 0℃; for 0.5h; Product distribution; New peptide deprotection procedure: hard-soft acid-base concept; the role of soft bases (thioanisole, dimethylsulfide, diphenylsulfide) employed.;	27.6%

3226-65-1

L-methionine sulfoxide

63-68-3

L-methionine

Conditions

Conditions	Yield
With hydrogen In water at 100℃; under 760.051 Torr; for 12h; chemoselective reaction;	90%
With dimethylsulfide; trifluorormethanesulfonic acid; 30 (v/v); trifluoroacetic acid at 0℃; for 4h; Yield given;
With hydrogenchloride at 108℃; for 16h;
With DL-dithiothreitol; methionine sulfoxide reductase A In aq. phosphate buffer at 37℃; pH=7.5; Kinetics; Enzymatic reaction;

Conditions

Conditions	Yield
With water at 40℃; for 2h;	90%

63-68-3

L-methionine

Conditions

Conditions	Yield
With boron trichloride In dichloromethane at 25℃; for 0.333333h;	90%

63-68-3

L-methionine

Conditions

Conditions	Yield
With ammonium formate; tris hydrochloride; nicotinamide adenine dinucleotide; formate dehydrogenase; phenylalanine dehydrogenase In water at 30℃; for 24h;	87%
With L-glutamic acid; pyridoxal 5'-phosphate In water at 40℃; for 12h; E.coli Aspartate transaminase, pH 8;	58%

(S)-2-(3,5-Dinitro-4-oxo-4H-pyridin-1-yl)-4-methylsulfanyl-butyric acid

(S)-2-(3,5-Dinitro-4-oxo-4H-pyridin-1-yl)-4-methylsulfanyl-butyric acid

A

63-68-3

L-methionine

B

74197-48-1

1-hexyl-3,5-dinitro-4-pyridone

Conditions

Conditions	Yield
In pyridine Product distribution;	A 85.1% B n/a

...Expand

L-Methionine Consensus Reports

L-Methionine Specification

The L-Methionine, with the CAS registry number 63-68-3,is also known as L-2-Amino-4-(methylthio)butyric acid. It belongs to the product categories of Amino Acids & Derivatives;Sulfur & Selenium Compounds. This chemical's molecular formula is C₅H₁₁NO₂S and molecular weight is 149.21.Its EINECS number is 200-562-9. What's more,Its systematic name is L-Methionine. It is a white crystalline powder which is a sulfur containing essential amino acid that is important in many body functions. It is a chelating agent for heavy metals. It is danger of cumulative effects. When you use it , you should avoid contact with skin and eyes.

L-Methionine has the following property datas:
(1)Freely Rotating Bonds: 5; (2)Polar Surface Area: 54.84; (3)Index of Refraction: 1.53; (4)Molar Refractivity: 38.26 cm³; (5)Molar Volume: 123.7 cm³; (6)Surface Tension: 50.5 dyne/cm; (7)Density: 1.206 g/cm³; (8)Flash Point: 139.4 °C; (9)Enthalpy of Vaporization: 60.21 kJ/mol; (10)Boiling Point: 306.9 °C at 760 mmHg; (11)Vapour Pressure: 0.00017 mmHg at 25°C; (12)Melting point: 276-279 °C (dec.); (13)Alpha: 23.25 o (c=2, 6N HCl); (14)Water solubility: Soluble; (15)Storage temp: Store at RT.

You could convert the following datas into the molecular structure:
(1). InChI: InChI=1S/C5H11NO2S/c1-9-3-2-4(6)5(7)8/h4H,2-3,6H2,1H3,(H,7,8)/t4-/m0/s1 
(2). InChIKey: InChIKey=FFEARJCKVFRZRR-BYPYZUCNSA-N 
(3). Smiles: C([C@H](CCSC)N)(O)=O

The toxicity data of L-Methionine are as follows:

Organism	Test Type	Route	Reported Dose (Normalized Dose)	Effect	Source
mouse	LD50	intraperitoneal	> 9500mg/kg (9500mg/kg)		Progress in Mutation Research. Vol. 1, Pg. 682, 1981.
rat	LD50	intraperitoneal	4328mg/kg (4328mg/kg)	LUNGS, THORAX, OR RESPIRATION: DYSPNEA	Archives of Biochemistry and Biophysics. Vol. 58, Pg. 253, 1955.
rat	LD50	oral	36gm/kg (36000mg/kg)	BEHAVIORAL: CHANGES IN MOTOR ACTIVITY (SPECIFIC ASSAY)	Gigiena i Sanitariya. For English translation, see HYSAAV. Vol. 48(6), Pg. 20, 1983.

Use of L-Methionine:
L-Methionine 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.

Production of L-Methionine:
L-Methionine could be produced through the following datas: