2568. Creatine

Nomenclature

CAS number: 57-00-1
N-(Aminoiminomethyl)-N-methylglycine; N-amidinosarcosine; (α-methylguanido)acetic acid; N-methyl-N-guanylglycine; methylglycocyamine.
C4H9N3O2; mol wt 131.13.
C 36.64%, H 6.92%, N 32.04%, O 24.40%.

Description and references

Amino acid that participates in the transfer of high energy phosphate in muscle cells. Predominantly found in skeletal and cardiac muscle; occurring also in its phosphorylated form, see phosphocreatine. Produced by liver, pancreas and kidneys by the transfer of the guanidine moiety of arginine to glycine which is then methylated to give creatine. First identified in meat extracts by Chevreul in 1835; name derived from the Greek “kreas,” meaning flesh. Synthesis by heating cyanamide with sarcosine: Strecker, Jahresber. Chem. 1868, 686; cf. Volhard, Z. Chem. 5, 318 (1869); Paulmann, Arch. Pharm. 232, 638 (1894); Bergmann, Zervas, Z. Physiol. Chem. 173, 80 (1928); King J. Chem. Soc. 1930, 2374. Use in diagnosis of myocardial infarction: J. Delanghe et al., Ann. Clin. Biochem. 25, 383 (1988). HPLC determn in cardiac muscle: T. Teerlink et al., Anal. Biochem. 214, 278 (1993). Review of role in energy metabolism: S. P. Bessman, C. L. Carpenter, Annu. Rev. Biochem. 54, 831-862 (1985). Review of efficacy and safety as nutritional supplement: A. S. Graham, R. C. Hatton, J. Am. Pharm. Assoc. 39, 803-810 (1999); of effects of dietary supplementation on exercise performance: T. W. Demant, E. C. Rhodes, Sports Med. 28, 49-60 (1999); A. Casey, P. L. Greenhaff, Am. J. Clin. Nutr. 72, Suppl., 607S-617S (2000).

Chemical structure

Properties

Monoclinic prisms from water as the monohydrate. Becomes anhydr at 100°; dec 303°. Neutral reaction to litmus. pKb (20°) 11.02. Adsorption on various chromatographic agents: Grettie, Williams, J. Am. Chem. Soc. 50, 671 (1928). Absorption spectrum: Abderhalden, Haas, Z. Physiol. Chem. 164, 7 (1927). One gram of the monohydrate dissolves in 75 ml water, in about 9 liters alcohol. Insol in ether.