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β-Alanine

Names
IUPAC name β-Alanine
Systematic IUPAC name 3-Aminopropanoic acid
Other names 3-Aminopropionic acid
Identifiers
CAS Number	107-95-9
3D model (JSmol)	Interactive image
ChEBI	CHEBI:16958
ChEMBL	ChEMBL297569
ChemSpider	234
DrugBank	DB03107
ECHA InfoCard	100.003.215
EC Number	203-536-5
IUPHAR/BPS	2365
KEGG	D07561
PubChem CID	239
UNII	11P2JDE17B
CompTox Dashboard (EPA)	DTXSID0030823
InChI InChI=1S/C3H7NO2/c4-2-1-3(5)6/h1-2,4H2,(H,5,6)Key: UCMIRNVEIXFBKS-UHFFFAOYSA-N InChI=1/C3H7NO2/c4-2-1-3(5)6/h1-2,4H2,(H,5,6)Key: UCMIRNVEIXFBKS-UHFFFAOYAL
SMILES O=C(O)CCN
Properties
Chemical formula	C3H7NO2
Molar mass	89.093 g/mol
Appearance	white bipyramidal crystals
Odor	odorless
Density	1.437 g/cm (19 °C)
Melting point	207 °C (405 °F; 480 K) (decomposes)
Solubility in water	54.5 g/100 mL
Solubility	soluble in methanol. Insoluble in diethyl ether, acetone
log P	-3.05
Acidity (pKa)	3.55 (carboxyl; H2O) 10.24 (amino; H2O)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Irritant
NFPA 704 (fire diamond)	2 1 0
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1000 mg/kg (rat, oral)
Safety data sheet (SDS)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Y verify (what is  ?) Infobox references

β-Alanine (beta-alanine) is a naturally occurring beta amino acid, which is an amino acid in which the amino group is attached to the β-carbon (i.e. the carbon two carbon atoms away from the carboxylate group) instead of the more usual α-carbon for alanine (α-alanine). The IUPAC name for β-alanine is 3-aminopropanoic acid. Unlike its counterpart α-alanine, β-alanine has no stereocenter.

Biosynthesis and industrial route

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.

Sources for β-alanine includes pyrimidine catabolism of cytosine and uracil.

Biochemical function

β-Alanine residues are rare. It is a component of the peptides carnosine and anserine and also of pantothenic acid (vitamin B₅), which itself is a component of coenzyme A. β-alanine is metabolized into acetic acid.

Precursor of carnosine

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.

Because β-alanine dipeptides are not incorporated into proteins, they can be stored at relatively high concentrations. 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. In carnosine, the pK_a of the imidazolium group is 6.83, which is ideal for buffering.

Receptors

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).

β-alanine has five known receptor sites, including GABA-A, GABA-C a co-agonist site (with glycine) on NMDA receptors, the aforementioned GlyR site, and blockade of GAT protein-mediated glial GABA uptake, making it a putative "small molecule neurotransmitter."

Athletic performance enhancement

There is evidence that β-alanine supplementation can increase exercise and cognitive performance, for some sporting modalities, and exercises within a 0.5–10 min time frame. β-alanine is converted within muscle cells into carnosine, which acts as a buffer for the lactic acid produced during high-intensity exercises, and helps delay the onset of neuromuscular fatigue.

Ingestion of β-alanine can cause paraesthesia, reported as a tingling sensation, in a dose-dependent fashion. Aside from this, no important adverse effect of β-alanine has been reported, however, there is also no information on the effects of its long-term usage or its safety in combination with other supplements, and caution on its use has been advised. Furthermore, many studies have failed to test for the purity of the supplements used and check for the presence of banned substances.

Metabolism

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.

Alternatively, β-alanine can be diverted into pantothenic acid and coenzyme A biosynthesis.

References

1. Haynes, William M., ed. (2016). CRC Handbook of Chemistry and Physics (97th ed.). CRC Press. pp. 5–88. ISBN 978-1498754286.
2. The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (11th ed.). Merck. 1989. ISBN 091191028X., 196.
3. Weast, Robert C., ed. (1981). CRC Handbook of Chemistry and Physics (62nd ed.). Boca Raton, Florida: CRC Press. p. C-83. ISBN 0-8493-0462-8..
4. 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: 707–710. doi:10.1039/J29690000707.
5. Miltenberger, Karlheinz (2005). "Hydroxycarboxylic Acids, Aliphatic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a13_507. ISBN 3527306730.
6. ^ "Beta-Alanine Supplementation For Exercise Performance". Archived from the original on 20 June 2017. Retrieved 21 September 2018.
7. 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. S2CID 6990201.
8. 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. S2CID 23988054.
9. 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 (1): 47–50. doi:10.1007/BF00376439. PMID 1735411. S2CID 24590951.
10. Bate-Smith, EC (1938). "The buffering of muscle in rigor: protein, phosphate and carnosine". Journal of Physiology. 92 (3): 336–343. doi:10.1113/jphysiol.1938.sp003605. PMC 1395289. PMID 16994977.
11. 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
12. Tiedje KE, Stevens K, Barnes S, Weaver DF (October 2010). "Beta-alanine as a small molecule neurotransmitter". Neurochem Int. 57 (3): 177–88. doi:10.1016/j.neuint.2010.06.001. PMID 20540981. S2CID 7814845.
13. ^ 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.
14. ^ 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.
15. ^ 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.
16. ^ 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.
17. Brisola, Gabriel M P; Zagatto, Alessandro M (2019). "Ergogenic Effects of β-Alanine Supplementation on Different Sports Modalities: Strong Evidence or Only Incipient Findings?". The Journal of Strength and Conditioning Research. 33 (1): 253–282. doi:10.1519/JSC.0000000000002925. PMID 30431532. S2CID 53441737.
18. Bryan Saunders; Kirsty Elliott-Sale; Guilherme G Artioli1; Paul A Swinton; Eimear Dolan; Hamilton Roschel; Craig Sale; Bruno Gualano (2017). "β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis FREE". British Journal of Sports Medicine. 51 (8): 658–669. doi:10.1136/bjsports-2016-096396. hdl:10059/1913. PMID 27797728. S2CID 25496458.{{cite journal}}: CS1 maint: numeric names: authors list (link)
19. Guilherme Giannini Artioli; Bruno Gualano; Abbie Smith; Jeffrey Stout; Antonio Herbert Lancha Jr. (June 2010). "Role of beta-alanine supplementation on muscle carnosine and exercise performance". Med Sci Sports Exerc. 42 (6): 1162–73. doi:10.1249/MSS.0b013e3181c74e38. PMID 20479615.
20. ^ "KEGG PATHWAY: beta-Alanine metabolism - Reference pathway". www.genome.jp. Retrieved 2016-10-04.

External links

• KEGG map of β-alanine metabolism Archived 2009-03-02 at the Wayback Machine

• Beta-Amino acids
• Ergogenic aids
• GABA reuptake inhibitors
• Glycine receptor agonists
• Non-proteinogenic amino acids
• Inhibitory amino acids