β-Alanine (or beta-alanine) is a naturally occurring beta amino acid, which is an amino acid in which the amino group is at the β-position from the carboxylate group (i.e., two atoms away, see Figure 1). The IUPAC name for β-alanine is 3-aminopropanoic acid. Unlike its counterpart α-alanine, β-alanine has no stereocenter.
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||89.093 g/mol|
|Appearance||white bipyramidal crystals|
|Density||1.437 g/cm3 (19 °C)|
|Melting point||207 °C (405 °F; 480 K) (decomposes)|
|54.5 g/100 mL|
|Solubility||soluble in methanol. Insoluble in diethyl ether, acetone|
|Safety data sheet|||
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|1000 mg/kg (rat, oral)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Biosynthesis and industrial routeEdit
In terms of its biosynthesis, it is formed by the degradation of dihydrouracil and carnosine. β-Alanine ethyl ester is the ethyl ester which hydrolyses within the body to form β-alanine. It is produced industrially by the reaction of ammonia with β-propiolactone.
β-Alanine is not found in any major proteins or enzymes. It is a component of the naturally occurring peptides carnosine and anserine and also of pantothenic acid (vitamin B5), which itself is a component of coenzyme A. Under normal conditions, β-alanine is metabolized into acetic acid.
β-Alanine is the rate-limiting precursor of carnosine, which is to say carnosine levels are limited by the amount of available β-alanine, not histidine. Supplementation with β-alanine has been shown to increase the concentration of carnosine in muscles, decrease fatigue in athletes and increase total muscular work done. Simply supplementing with carnosine is not as effective as supplementing with β-alanine alone since carnosine, when taken orally, is broken down during digestion to its components, histidine and β-alanine. Hence, by weight, only about 40% of the dose is available as β-alanine.
L-Histidine, with a pKa of 6.1 is a relatively weak buffer over the physiological intramuscular pH range. However, when bound to other amino acids, this increases nearer to 6.8-7.0. In particular, when bound to β-alanine, the pKa value is 6.83, making this a very efficient intramuscular buffer. Furthermore, because of the position of the beta amino group, β-alanine dipeptides are not incorporated into proteins, and thus can be stored at relatively high concentrations (millimolar). Occurring at 17–25 mmol/kg (dry muscle), carnosine (β-alanyl-L-histidine) is an important intramuscular buffer, constituting 10-20% of the total buffering capacity in type I and II muscle fibres.
Even though much weaker than glycine (and, thus, with a debated role as a physiological transmitter), β-alanine is an agonist next in activity to the cognate ligand glycine itself, for strychnine-sensitive inhibitory glycine receptors (GlyRs) (the agonist order: glycine ≫ β-alanine > taurine ≫ alanine, L-serine > proline).
Athletic performance enhancementEdit
Sources for β-alanine includes pyrimidine catabolism of cytosine and uracil.
β-Alanine can undergo a transamination reaction with pyruvate to form malonate-semialdehyde and L-alanine. The malonate semialdehyde can then be converted into malonate via malonate-semialdehyde dehydrogenase. Malonate is then converted into malonyl-CoA and enter fatty acid biosynthesis.
- Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. p. 5–88. ISBN 978-1498754286.
- The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (11th ed.), Merck, 1989, ISBN 091191028X, 196.
- Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, FL: CRC Press. p. C-83. ISBN 0-8493-0462-8..
- Wright, Margaret Robson (1969). "Arrhenius parameters for the acid hydrolysis of esters in aqueous solution. Part I. Glycine ethyl ester, β-alanine ethyl ester, acetylcholine, and methylbetaine methyl ester". Journal of the Chemical Society B: Physical Organic: 707. doi:10.1039/J29690000707.
- Karlheinz Miltenberger "Hydroxycarboxylic Acids, Aliphatic" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a13_507
- "Beta-Alanine Supplementation For Exercise Performance". Retrieved 21 September 2018.
- Derave W, Ozdemir MS, Harris R, Pottier A, Reyngoudt H, Koppo K, Wise JA, Achten E (August 9, 2007). "Beta-alanine supplementation augments muscle carnosine content and attenuates fatigue during repeated isokinetic contraction bouts in trained sprinters". J Appl Physiol. 103 (5): 1736–43. doi:10.1152/japplphysiol.00397.2007. PMID 17690198.
- Hill CA, Harris RC, Kim HJ, Harris BD, Sale C, Boobis LH, Kim CK, Wise JA (2007). "Influence of beta-alanine supplementation on skeletal muscle carnosine concentrations and high intensity cycling capacity". Amino Acids. 32 (2): 225–33. doi:10.1007/s00726-006-0364-4. PMID 16868650.
- Bate-Smith, EC (1938). "The buffering of muscle in rigor: protein, phosphate and carnosine". Journal of Physiology. 92 (3): 336–343. PMC 1395289. PMID 16994977.
- Mannion, AF; Jakeman, PM; Dunnett, M; Harris, RC; Willan, PLT (1992). "Carnosine and anserine concentrations in the quadriceps femoris muscle of healthy humans". Eur. J. Appl. Physiol. 64: 47–50. doi:10.1007/BF00376439.
- Encyclopedia of Life Sciences Amino Acid Neurotransmitters. Jeremy M Henley, 2001 John Wiley & Sons, Ltd. doi:10.1038/npg.els.0000010, Article Online Posting Date: April 19, 2001
- Quesnele JJ, Laframboise MA, Wong JJ, Kim P, Wells GD (2014). "The effects of beta-alanine supplementation on performance: a systematic review of the literature". Int J Sport Nutr Exerc Metab (Systematic review). 24 (1): 14–27. doi:10.1123/ijsnem.2013-0007. PMID 23918656.
- Hoffman JR, Stout JR, Harris RC, Moran DS (2015). "β-Alanine supplementation and military performance". Amino Acids. 47 (12): 2463–74. doi:10.1007/s00726-015-2051-9. PMC 4633445. PMID 26206727.
- Hobson, R. M.; Saunders, B.; Ball, G.; Harris, R. C.; Sale, C. (9 December 2016). "Effects of β-alanine supplementation on exercise performance: a meta-analysis". Amino Acids. 43 (1): 25–37. doi:10.1007/s00726-011-1200-z. ISSN 0939-4451. PMC 3374095. PMID 22270875.
- Trexler ET, Smith-Ryan AE, Stout JR, Hoffman JR, Wilborn CD, Sale C, Kreider RB, Jäger R, Earnest CP, Bannock L, Campbell B, Kalman D, Ziegenfuss TN, Antonio J (2015). "International society of sports nutrition position stand: Beta-Alanine". J Int Soc Sports Nutr (Review). 12: 30. doi:10.1186/s12970-015-0090-y. PMC 4501114. PMID 26175657.
- "KEGG PATHWAY: beta-Alanine metabolism - Reference pathway". www.genome.jp. Retrieved 2016-10-04.