Title: Histidine
CAS Registry Number: 71-00-1
CAS Name: L-Histidine
Additional Names: His; H; (S)-a-amino-1H-imidazole-4-propanoic acid; a-amino-4(or 5)-imidazolepropionic acid; glyoxaline-5-alanine
Molecular Formula: C6H9N3O2
Molecular Weight: 155.15
Percent Composition: C 46.45%, H 5.85%, N 27.08%, O 20.62%
Literature References: Essential amino acid for human development; precursor to histamine and a component of carnosine, q.v. Independently isolated in 1896 by both A. Kossel and S. G. Hedin, Zeit. Physiol. 22, 176, 191 (1896). 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. 1971-1995, passim. NMR spectra: D. H. Sachs et al., J. Biol. Chem. 246, 6576 (1971). HPLC determn in dipeptides: E. Kasziba et al., J. Chromatogr. 432, 315 (1988). Often found at the active site of proteins: W. T. Morgan et al., J. Biol. Chem. 268, 6256 (1993); J.-W. P. Boots et al., Biochim. Biophys. Acta 1248, 27 (1995). Role in proton translocation - a model: J. E. Morgan et al., J. Bioenerg. Biomembr. 26, 599 (1994). Review of metabolism: F. B. Stifel, R. H. Herman, Am. J. Clin. Nutr. 24, 207-217 (1971). Review of role in nutrition: eidem, ibid. 25, 182-185 (1972); L. P. Mercer et al., Nutrition 6, 273-277 (1990).
Properties: Sweet needles or plates, dec 287° (softens at 277°). [a]D20 -10.9° (c = 0.77 in 0.5N NaOH); [a]D25 -38.95° (c = 0.75 to 3.77); [a]D25 +13.34° (c = 1.00-4.05 in 6.1N HCl). pK1 1.82; pK2 6.00; pK3 9.17. Soly in water at 25°: 41.9 g/l. Insol in common neutral solvents except water.
pKa: pK1 1.82; pK2 6.00; pK3 9.17
Optical Rotation: [a]D20 -10.9° (c = 0.77 in 0.5N NaOH); [a]D25 -38.95° (c = 0.75 to 3.77); [a]D25 +13.34° (c = 1.00-4.05 in 6.1N HCl)
Derivative Type: Monohydrochloride
Trademarks: Ecristidine; Laristine (Roche); Larostidin (Roche); Plexamine (Biodica)
Molecular Formula: C6H9N3O2.HCl
Molecular Weight: 191.62
Percent Composition: C 37.61%, H 5.26%, N 21.93%, O 16.70%, Cl 18.50%
Properties: Rhombic crystals, dec 251-252° (also forms a monohydrate, mp 80°, anhydrous, mp at 140°). [a]D26 +8.0° (c = 2 in 3 mols HCl). Fairly sol in water. Insol in alcohol, ether.
Melting point: Rhombic crystals, dec 251-252° (also forms a monohydrate, mp 80°, anhydrous, mp at 140°)
Optical Rotation: [a]D26 +8.0° (c = 2 in 3 mols HCl)
Derivative Type: DL-Form
Properties: Quadrilateral plates or tetragonal prisms, dec 285°. Sol in water.
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