Beta-alanine is formed by the proteolytic degradation of beta-alanine containing dipeptides: carnosine, anserine, balenine, and pantothenic acid (vitamin B5). These dipeptides are found in protein rich foods such as chicken, beef, pork and fish. Beta-alanine can also be formed in the liver from the catabolism of pyrimidine nucleotides which are broken down into uracil and dihydrouracil and then metabolized into beta-alanine and beta-aminoisobutyrate. Beta-alanine can also be formed via the action of aldehyde dehydrogenase on beta-aminoproionaldehyde which is generated from various aliphatic polyamines. Under normal conditions, beta-alanine is metabolized to aspartic acid through the action of glutamate decarboxylase. It can also be converted to malonate semialdehyde and thereby participate in propanoate metabolism. Beta-alanine is not a proteogenic amino acid.