Chemical Properties
White powder
Occurrence
Creatine is an amino acid that occurs naturally in dairy products, seafood, and beef. It is manufactured by the body in the liver, kidney, and pancreas.
Definition
ChEBI: Creatine is a glycine derivative having methyl and amidino groups attached to the nitrogen. It has a role as a neuroprotective agent, a nutraceutical, a human metabolite, a mouse metabolite and a geroprotector. It is a member of guanidines and a glycine derivative. It is a conjugate acid of a creatinate. It is a tautomer of a creatine zwitterion.
Biochem/physiol Actions
Creatine is a nitrogenous compound that acts as a high-energy reservoir for the rapid regeneration of ATP. Approximately 95% of creatine is found in skeletal muscle, primarily as phosphocreatine. Creatine can be acquired through dietary consumption or formed from L-arginine, glycine, and L-methionine in a multi-step reaction that occurs in the kidneys and liver. Creatine is then transported to muscle tissue. Creatine supplementation is used for the enhancement of sports performance, primarily by increasing muscle mass. Creatine is also being investigated as a treatment of neuromuscular diseases, where it may aid in neuroprotection and by improving the cellular bioenergetic state.
Purification Methods
Likely impurities are creatinine and other guanidino compounds. It crystallises from the minimum volume of boiling H2O as the monohydrate. The hydrate is also obtained by dissolving in H2O and adding Me2CO. Drying under vacuum over P2O5 or drying at 100o gives the anhydrous base. The anhydrous base can be obtained also by dissolving the hydrate in H2O, seeding with the anhydrous base and cooling in ice. A m of 258 -268o(dec) was reported. The picrate crystallises from 17 parts of H2O with m of 218-220o(dec). [King J Chem Soc 2377 1930, Hoffmann et al. J Am Chem Soc 58 1730 1936, Mendel & Hodgkin Acta Cryst 7 443 1954, Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 p 2750 1961, Beilstein 4 III 1170, 4 IV 2425.]