Title: Carnosine
CAS Registry Number: 305-84-0
CAS Name: b-Alanyl-L-histidine
Additional Names: ignotine
Molecular Formula: C9H14N4O3
Molecular Weight: 226.23
Percent Composition: C 47.78%, H 6.24%, N 24.77%, O 21.22%
Literature References: Naturally occurring dipeptide found in large amounts in skeletal muscle. Also present in other tissues such as brain, cardiac muscle, kidney. Water soluble antioxidant; functions as a free-radical scavenger. Isoln: Gulewitsch, Amiradzibi, Ber. 33, 1902 (1900); Wolff, Wilson, J. Biol. Chem. 95, 495 (1932); 109, 565 (1935). Synthesis from histidine and b-iodo- or b-nitropropionyl chloride: Baumann, Ingvaldsen, ibid. 35, 271 (1918); Barger, Tutin, Biochem. J. 12, 406 (1918). Later syntheses: Sifford, du Vigneaud, J. Biol. Chem. 108, 753 (1935); R. A. Turner, J. Am. Chem. Soc. 75, 2388 (1953); F. J. Vinick, S. Jung, J. Org. Chem. 48, 392 (1983). Crystal structure: H. Itoh et al., Acta Crystallogr. 33B, 2959 (1977). Possible role in wound healing: D. E. Fischer et al., Proc. Soc. Exp. Biol. Med. 158, 402 (1978). Review of physiological properties and therapeutic potential: S. E. Gariballa, A. J. Sinclair, Age Ageing 29, 207-210 (2000).
Properties: Crystals from aqueous ethanol, mp 262° (dec) (Vinick, Jung); also reported as mp 260° (capillary tube) and as mp 308-309° (Dennis bar) (Sifford, du Vigneaud). [a]D25 +21.0° (c = 1.5 in water). pK1 2.64; pK2 6.83; pK3 9.51. Alkaline reaction. One gram dissolves in 3.1 ml water at 25°.
Melting point: mp 262° (dec) (Vinick, Jung); mp 260° (capillary tube) and as mp 308-309° (Dennis bar) (Sifford, du Vigneaud)
pKa: pK1 2.64; pK2 6.83; pK3 9.51
Optical Rotation: [a]D25 +21.0° (c = 1.5 in water)
Derivative Type: Nitrate
CAS Registry Number: 5852-98-2
Molecular Formula: C9H15N5O6
Molecular Weight: 289.25
Percent Composition: C 37.37%, H 5.23%, N 24.21%, O 33.19%
Properties: Crystals, dec 222°. [a]D20 +24.1° (c = 1.5 in water). Very sol in water.
Optical Rotation: [a]D20 +24.1° (c = 1.5 in water)
Derivative Type: Hydrochloride
CAS Registry Number: 5852-99-3
Molecular Formula: C9H15ClN4O3
Molecular Weight: 262.69
Percent Composition: C 41.15%, H 5.76%, Cl 13.50%, N 21.33%, O 18.27%
Properties: Crystals, dec 245°. Very sol in water.
Derivative Type: D-Form
CAS Registry Number: 5853-00-9
Properties: Crystals, mp 260°. [a]D28 -20.4° (c = 1.5).
Melting point: mp 260°
Optical Rotation: [a]D28 -20.4° (c = 1.5)
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