b-Alanine

β-Alanine (3-Aminopropanoic acid) is a naturally occurring beta amino acid formed in vivo by the degradation of dihydrouracil and carnosine. It acts as a neurotransmitter by activating glycine and GABA receptors.

β-cyano-L-Alanine (Beta-cyano-l-alanine) is a commonly occurring nitrile found in higher plants.

3-Amino-2-methylpropanoic acid (α-Methyl-β-alanine) is the product from the conversion of N-carbamyl-beta-aminoisobutyric acid by the enzyme Beta-ureidopropionase (EC 3.5.1.6), the last step in pyrimidine degradation. Beta-ureidopropionase deficiency is an inborn error of pyrimidine degradation associated with neurological abnormalities.

β-N-Methylamino-L-alanine hydrochloride (L-BMAA hydrochloride) is a neurotoxin produced by cyanobacteria that may contribute to the development of amyotrophic lateral sclerosis (ALS) and possibly other neurodegenerative diseases.

Ureidopropionic acid (3-Ureidopropionic acid) is an intermediate in uracil metabolism, produced from dihydrouracil by the enzyme dihydropyrimidase and further decomposed to beta-alanine by beta-ureidopropionase. It is a urea derivative of beta-alanine. High levels of Ureidopropionic acid are found in individuals with beta-ureidopropionase (UP) deficiency. Enzyme deficiencies in pyrimidine metabolism are associated with severe toxicity to the antineoplastic agent 5-fluorouracil.