L-валин

Описание

Valine (abbreviated as Val or V) is an α-amino acid with the chemical formula HO₂CCH(NH₂)CH(CH₃)₂. L-Valine is one of 20 proteinogenic amino acids. Its codons are GUU, GUC, GUA, and GUG. This essential amino acid is classified as nonpolar. Human dietary sources are any proteinaceous foods such as meats, dairy products, soy products, beans and legumes.
Along with leucine and isoleucine, valine is a branched-chain amino acid. It is named after the plant valerian. In sickle-cell disease, valine substitutes for the hydrophilic amino acid glutamic acid in hemoglobin. Because valine is hydrophobic, the hemoglobin is prone to abnormal aggregation.

Химические свойства

White or almost white, crystalline powder or colourless crystals, soluble in water, very slightly soluble in alcohol.

Определение

ChEBI: The L-enantiomer of valine.

Биосинтез

Valine is an essential amino acid, hence it must be ingested, usually as a component of proteins. It is synthesized in plants via several steps starting from pyruvic acid. The initial part of the pathway also leads to leucine. The intermediate α-ketoisovalerate undergoes reductive amination with glutamate. Enzymes involved in this biosynthesis include :
Acetolactate synthase
Acetohydroxy acid isomeroreductase
Dihydroxyacid dehydratase
Valine aminotransferase.

Общее описание

Valine is an essential amino acid, involved in the biosynthesis of glutamine and alanine. Valine being a branched-chain amino acid (BCAA), maintains a balance among the BCAAs. L-Valine serves as an energy fuel.

Побочные эффекты

L-valine is a natural substance that is necessary for our health. As such, it generally does not have any side effects. However, taking large quantities of L-valine can cause fatigue, nausea, and a lack of muscle coordination.
Extremely high doses of L-valine can be dangerous. Excessive levels of L-valine can cause your body to produce excess ammonia which is toxic.
Extremely high levels of L-valine can cause your skin to tingle and can lead to hallucinations.

Профиль безопасности

Mutation data reported. When heated to decomposition it emits toxic fumes of NOx.

Методы очистки

Crystallise L-valine from water by addition of EtOH. It sublimes at 178-188o/0.03mm with 99.3% recovery and unracemised [Gross & Gradsky J Am Chem Soc 77 1678 1955]. [Perrin J Chm Soc 3125 1958, Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 pp 2368-23771961, Beilstein 4 IV 2659.]