Beta-Alanine is a naturally occurring beta amino acid, which is an amino acid in which the amino group is at the Beta-position from the carboxylate group . The IUPAC name for Beta-alanine is 3-aminopropanoic acid. Unlike its counterpart α-alanine, Beta-alanine has no stereocenter. Biosynthesis and industrial route In terms of its biosynthesis, it is formed by the degradation of dihydrouracil and carnosine.
Beta-Alanine ethyl ester is the ethyl ester which hydrolyses within the body to form Beta-alanine. It is produced industrially by the reaction of ammonia with Beta-propiolactone. Biochemical function Beta-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, which itself is a component of coenzyme A.
Under normal conditions, Beta-alanine is metabolized into acetic acid. Beta-Alanine is the rate-limiting precursor of carnosine, which is to say carnosine levels are limited by the amount of available Beta-alanine, not histidine. Supplementation with Beta-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 Beta-alanine alone since carnosine, when taken orally, is broken down during digestion to its components, histidine and Beta-alanine. Hence, by weight, only about 40% of the dose is available as Beta-alanine. making this a very efficient intramuscular buffer. Furthermore, because of the position of the beta amino group, Beta-alanine dipeptides are not incorporated into proteins, and thus can be stored at relatively high concentrations .
Occurring at 17–25 mmol/kg, carnosine 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, Beta-alanine is an agonist next in activity to the cognate ligand glycine itself, for strychnine-sensitive inhibitory glycine receptors . Athletic performance enhancement There is evidence that Beta-alanine supplementation can increase exercise and cognitive performance, but there is concern about lack of information about safety.
Metabolism Sources for Beta-alanine includes pyrimidine catabolism of cytosine and uracil. Beta-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, Beta-alanine can be diverted into pantothenic acid and coenzyme A biosynthesis.
