204. Alanine

Nomenclature

CAS number: 56-41-7
l-Alanine; Ala; A; l-α-alanine; l-α-aminopropionic acid; (S)-2-aminopropanoic acid.
C3H7NO2; mol wt 89.09.
C 40.44%, H 7.92%, N 15.72%, O 35.92%.

Description and references

Non-essential amino acid for human development. First syllable of the name denotes its origin from aldehyde. First synthesized and named by: A. Strecker, Ann. 75, 27 (1850); prior to identification in silk hydrolysate: P. Schützenberger, A. Bourgeous, Compt. Rend. 81, 191 (1875); Th. Weyl, Ber. 21, 1407 (1888). 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. 1819-1840, passim. Enantiomeric selective synthesis: R. Amoroso et al., J. Org. Chem. 57, 1082 (1992) DOI. Review of metabolism in man: J. E. Liljenquist et al., Clin. Nutr. Update, H. L. Greene et al., Eds. (American Medical Association, Chicago, IL, 1977) pp 22-34; T. N. Palmer et al., Biosci. Rep. 5, 1015-1033 (1985) DOI PubMed. Review of industrial production by microorganisms: S. Takamatsu, T. Tosa, Bioprocess Technol. 16, 25-35 (1993) PubMed.

Chemical structure

Properties

Orthorhombic crystals from water, dec 297°. d 1.401. [α]D25 +2.42° (c = 10 in H2O); +13.7° (c = 2.06 in 6N HCl). pK1 2.34; pK2 9.69. Soly (g/l) in water at 0°: 127.3; at 25°: 166.5; at 50°: 217.9; at 75°: 285.1; at 100°: 373.0. Soly in cold 80% ethanol: 0.2%. Freely sol in water. Insol in ether.

Derivative

d-Form.

Nomenclature

CAS number: 338-69-2

Description and references

Occurs in bacterial cell walls and in some peptide antibiotics. Review: M. Bodanszky, D. Perlman, Science 163, 352-358 (1969); C. T. Walsh, J. Biol. Chem. 264, 2393-2396 (1989).

Properties

Crystals, mp 289-291°. [α]D 14.1° (c = 0.9 in 1N HCl).

Derivative

dl-Form.

Nomenclature

CAS number: 302-72-7

Properties

Orthorhombic bipyramidal needles or rods from water. d 1.424. Sublimes above 200°. Decomp 264-296° depending on rate of heating. pK1 2.35; pK2 9.87. Soly in water at 0°: 121 g/l, at 25°: 167 g/l, at 50°: 231 g/l, at 75°: 319 g/l, at 100°: 440 g/l; in ethanol 0.0087 g/100 g at 25°. Insol in ether.