D-Alanine

A white crystalline Powder with no peculiar smell and a sweet taste. It is easily soluble in water, slightly soluble in ethanol, and insoluble in acetone and ether. The decomposition point is 297°C. The specific rotation is [α]25D -1.8° (0.5–2.0 mg/ml, H2O) and [α]25D -14.6° (0.5–2.0 mg/ml, 5 mol/L HCl).

D-Alanine is essential for the biosynthesis of peptidoglycan crosslinking sub-units that are used for bacterial cell walls.

ChEBI: D-alanine is the D-enantiomer of alanine. It has a role as a human metabolite, an EC 4.3.1.15 (diaminopropionate ammonia-lyase) inhibitor and an Escherichia coli metabolite. It is a D-alpha-amino acid and an alanine. It is a conjugate base of a D-alaninium. It is a conjugate acid of a D-alaninate. It is an enantiomer of a L-alanine. It is a tautomer of a D-alanine zwitterion.

D-Alanine can be obtained by hydrolysis and refining of proteins such as gelatin, sericin and corn protein, or it can be synthesized by chemical methods.

D-Alanine is a LHRH-antagonists, e.g., Abarelix (antineoplas- tic)

Alanine is a non essential amino acid.

D-Alanine is the non-proteinogenic form of alanine which is used in bacterial cell wall biosynthesis. D-Alanine is used to study the specificity and kinetics of alanine racemase(s) (alaR).

Crystallise alanine from H2O or aqueous EtOH, i.e. crystallise it from 25% EtOH in water, or recrystallise it from 62.5% EtOH, wash it with EtOH and dry it to constant weight in vacuo over P2O5. [Gutter & Kegeles J Am Chem Soc 75 3893 1953, Walsh J Biol Chem 264 2394 1989.] 2,2'-Iminodipropionic acid is a likely impurity. [Beilstein 4 IV 2480. 2481.]

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