1850. Carnosine

Nomenclature

CAS number: 305-84-0
β-Alanyl-l-histidine; ignotine.
C9H14N4O3; mol wt 226.23.
C 47.78%, H 6.24%, N 24.77%, O 21.22%.

Description and 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 β-iodo- or β-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).

Chemical structure

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). [α]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°.

Derivative

Nitrate.

Nomenclature

CAS number: 5852-98-2
C9H15N5O6; mol wt 289.25.
C 37.37%, H 5.23%, N 24.21%, O 33.19%.

Properties

Crystals, dec 222°. [α]D20 +24.1° (c = 1.5 in water). Very sol in water.

Derivative

Hydrochloride.

Nomenclature

CAS number: 5852-99-3
C9H15ClN4O3; mol wt 262.69.
C 41.15%, H 5.76%, Cl 13.50%, N 21.33%, O 18.27%.

Properties

Crystals, dec 245°. Very sol in water.

Derivative

d-Form.

Nomenclature

CAS number: 5853-00-9

Properties

Crystals, mp 260°. [α]D28 -20.4° (c = 1.5).