9909. Valine

Nomenclature

CAS number: 72-18-4
l-Valine; Val; V; 2-aminoisovaleric acid; 2-amino-3-methylbutyric acid; α-aminoisovaleric acid; (S)-2-amino-3-methylbutanoic acid.
C5H11NO2; mol wt 117.15.
C 51.26%, H 9.46%, N 11.96%, O 27.31%.

Description and references

An essential amino acid for human development. Identified from organ extracts in 1856 by von Group-Besanez; isolated from proteins in 1879 by Schützenberger who proposed that it was aminovaleric acid. Structure confirmation: E. Fischer, Ber. 39, 2320 (1906). Early chemistry and biochemistry: Amino Acids and Proteins, D. M. Greenberg, Ed. (Charles C. Thomas, Springfield, IL, 1951) 950 pp., passim; J. P. Greenstein, M. Winitz, Chemistry of the Amino Acids vols 1-3 (John Wiley and Sons, Inc., New York, 1961) pp. 2368-2380, passim. Conformation study: R. H. Yun, J. Hermans, Protein Eng. 4, 761 (1991). Nutritional assessment study: V. R. Young et al., J. Nutr. 102, 1159 (1972); in parenteral nutrition: P. Reiderer et al., Nutr. Metab. 24, 209 (1980); in hemodialysis patients: G. A. Young et al., Kidney Int. 21, 492 (1982). Brief review of metabolism: P. Kamoun, Trends Biochem. Sci. 17, 175-176 (1992).

Chemical structure

Properties

Leaflets from water + alcohol, mp 315° (closed capillary). d 1.230. Sublimes. [M]D +33.1° (5N HCl); +72.6° (glacial acetic acid); [α]D23 +22.9° (c = 0.8 in 20% HCl). pK1 2.32; pK2 9.62. Soly at 25°: 5.74±0.05 g/100 g water. Insol in common neutral solvents.

Derivative

dl-Form.

Properties

Sublimes without melting at ordinary speed of heating. Dec 298° (closed capillary, very rapid heating). One part dissolves in 11.7 parts of water at 15°, in 14.1 parts of water at 25°. Insol in common neutral solvents.