beta-Alanine
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Names | |
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IUPAC name
3-Aminopropanoic acid
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Other names
β-Alanine
3-Aminopropionic acid |
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Identifiers | |
107-95-9 ![]() |
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3D model (Jmol) | Interactive image |
ChEBI | CHEBI:16958 ![]() |
ChEMBL | ChEMBL297569 ![]() |
ChemSpider | 234 ![]() |
DrugBank | DB03107 ![]() |
ECHA InfoCard | 100.003.215 |
EC Number | 203-536-5 |
2365 | |
KEGG | D07561 ![]() |
PubChem | 239 |
UNII | 11P2JDE17B ![]() |
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Properties[1][2] | |
C3H7NO2 | |
Molar mass | 89.093 g/mol |
Appearance | white bipyramidal crystals |
Odor | odorless |
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 |
log P | -3.05 |
Acidity (pKa) | 3.63 |
Hazards | |
Main hazards | Irritant |
Safety data sheet | [1] |
NFPA 704 | |
Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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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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Infobox references | |
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.
β-Alanine is not used in the biosynthesis of any major proteins or enzymes. It is formed in vivo by the degradation of dihydrouracil and carnosine. 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.[3] 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.[4][5] 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.[3]
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,[6] 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),[7] 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).[8]
Athletic performance enhancement[edit]
There is evidence that β-alanine supplementation can increase exercise performance, but concern about lack of information about safety.[9][10][11][12]
Ingestion of β-Alanine can cause paraesthesia, reported as a tingling sensation, in a dose-dependent fashion.[12]
Metabolism[edit]
Sources for β-alanine includes pyrimidine catabolism of cytosine and uracil.
β-alanine can undergo a transanimation 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.[13]
Alternatively, β-alanine can be diverted into Pantothenate and Coenzyme A biosynthesis.[13]
References[edit]
- ^ 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..
- ^ a b http://pharmacistanswers.com/beta-alanine-supplementation-for-exercise-performance.html
- ^ 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.
- ^ a b 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.
- ^ a b "KEGG PATHWAY: beta-Alanine metabolism - Reference pathway". www.genome.jp. Retrieved 2016-10-04.