4491. Glycine

Nomenclature

CAS number: 56-40-6
Gly; G; aminoacetic acid; aminoethanoic acid; glycocoll; Gyn-Hydralin (Lefrancq).
C2H5NO2; mol wt 75.07.
C 32.00%, H 6.71%, N 18.66%, O 42.63%.

Description and references

Non-essential amino acid for human development. Only amino acid with no asymmetric carbon. Major inhibitory neurotransmitter. Isoln from gelatin: H. Braconnot, Ann. Chim. Phys. 13, 113 (1820). 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. 1955-1970, passim. Exists in three polymorphic forms, α-, β-, and γ-: Y. Iitaka, Nature 183, 390 (1959). Review of metabolism and radioprotection: S. Capalna, Rev. Roum. Physiol. 9, 17-34 (1972); of metabolism in humans: A. A. Jackson, M. H. Golden, Clin. Sci. 58, 517-522 (1980); in anerobes: J. R. Andreesen, Antonie van Leeuwenhoek 66, 223-227 (1994). Review of role in neurotransmission: S. M. Paul in Psychopharmacology: The Fourth Generation of Progress, F. E. Bloom, D. J. Kupfer, Eds. (Raven Press, New York, 1995) pp 87-94. Book: Glycine Neurotransmission, O. P. Ottersen, J. Storm-Mathisen, Eds. (John Wiley & Sons, Chichester, U.K., 1990) pp 489.

Chemical structure

Properties

Sweet, monoclinic prisms from alc, starts to dec at 233°, completely sintered at 290°. d 1.595. pK1 2.34; pK2 9.60. pH of 0.2 molar soln in H2O = 4.0. Adsorption on various chromatographic agents: Grettie, Williams, J. Am. Chem. Soc. 50, 671 (1928). Soly in 100 ml water at 25°: 25.0 g; at 50°: 39.1 g; at 75°: 54.4 g; at 100°: 67.2 g. 100 g of abs alc dissolve about 0.06 g. Sol in 164 parts pyridine. Almost insol in ether.

Derivative

Hydrochloride.

Nomenclature

CAS number: 6000-43-7
C2H5NO2.HCl; mol wt 111.53.
C 21.54%, H 5.42%, N 12.56%, O 28.69%, Cl 31.79%.

Properties

Hygroscopic prisms from HCl, mp 182°.

Use

Buffer. Reagent in synthetic organic chemistry.