Non-essential amino acid for human development; most abundant free amino acid in plasma and tissue. Isoln from sugarbeet juice: E. Schulze, E. Bosshard, Ber. 16, 312 (1883). Due to ease of conversion to glutamic acid, q.v., it was not isolated from protein until 1932: M. Damodoran et al., Biochem. J. 26, 1704 (1932). Early chemistry and biochemistry: R. M. Archibald, Chem. Rev. 37, 161-208 (1945); 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 vol 1-3 (John Wiley and Sons, Inc., New York, 1961) pp. 1929-1954, passim. HPLC determn in biotech samples: B. Polanuer et al., J. Chromatogr. 594, 173 (1992). Review of nutritive needs: R. J. Smith, D. W. Wilmore, J. Parenter. Enteral Nutr. 14, (Suppl.) 94S-99S (1990); and metabolism: W. W. Souba, J. Nutr. Biochem. 4, 2-9 (1993); L. M. Castell et al., Amino Acids 7, 231-243 (1994). Review of metabolism and physiologic implications: R. J. Smith, J. Parenter. Enteral Nutr. 14, (Suppl.) 40S-44S (1990); B. Moskovitz et al., Pharmacol. Res. 30, 61-71 (1994).
Synthesis: F. E. King, D. A. A. Kidd, J. Chem. Soc. 1949, 3315; G. B. Kline, S. H. Cox, J. Org. Chem. 26, 1854 (1961).