L-Methionine

Product Description

Name:L-Methionine
Synonyms:L-2-Amino-4-(methylthio)butyric acid 
Molecular Formula;C5H11NO2S
Molecular Weight:149.21
CAS Registry Number:63-68-3
EINECS :200-562-9
This essential amino acid is classified as nonpolar.
Together with cysteine, methionine is one of two sulfur-containing proteinogenic amino acids. Its derivative S-adenosyl methionine (SAM) serves as a methyl donor. Methionine is an intermediate in the biosynthesis of cysteine, carnitine, taurine, lecithin, phosphatidylcholine, and other phospholipids. Improper conversion of methionine can lead to atherosclerosis.
This amino acid is also used by the Plants for synthesis of ethylene. The process is known as the Yang Cycle or the Methionine cycle.
Methionine is one of only two amino acids encoded by a single codon (AUG) in the standard genetic code (tryptophan, encoded by UGG, is the other). The codon AUG is also the "Start" message for a ribosome that signals the initiation of protein translation from mRNA. As a consequence, methionine is incorporated into the N-terminal position of all proteins in eukaryotes and archaea during translation, although it is usually removed by post-translational modification.
Specification:
Item
 Specifications
 
Appearance
 White crystals or crystalline powder
 
Assay
 99.0101.0%
 
Specific rotation
 +22.4+24.8
 
pH
 5.66.1
 
Residue on ignition
 0.40%
 
Chloride (CL)
 0.05%
 
Loss on drying
 0.30%
 
Sulfate(SO4)
 0.03%
 
Iron,(Fe)
 30ppm
 
Heavy metals ,(Pb)
 15ppm
 
Organic volatile impurities
 Meets the requirements
 

Packing:25kg/fiber drum
Storage:be preserved in shady and cool place in closed containers
Shelf life:2years