Aspartic acid

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Aspartic acid
IUPAC name Trivial: Aspartic acid
Systematic: 2-Aminobutanedioic acid
Other names Aminosuccinic acid, asparagic acid, asparaginic acid[1]
CAS number 617-45-8,
56-84-8 (L-isomer)
1783-96-6 (D-isomer)
PubChem 424
EC-number 200-291-6
InChI InChI=1/C4H7NO4/c5-2(4(8)9)1-3(6)7/h2H,1,5H2,(H,6,7)(H,8,9)
Molecular formula C4H7NO4
Molar mass 133.1 g mol-1
MSDS External MSDS
EU Index not listed
Supplementary data page
Structure and
n, εr, etc.
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Aspartic acid (abbreviated as Asp or D; Asx or B represent either aspartic acid or asparagine)[2] is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CO2H. The carboxylate anion of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins. Its codons are GAU and GAC.

Aspartic acid is, together with glutamic acid, classified as an acidic amino acid with a pKa of 4.0. Aspartate is pervasive in biosynthesis. As with all amino acids, the presence of acid protons depends on the residue's local chemical environment and the pH of the solution.


Aspartic acid was first discovered in 1827 by Plisson, synthesized by boiling asparagine (discovered in 1806) with a base.[3]

Forms and nomenclature

The term "aspartic acid" refers to either of two forms or a mixture of two.[2] Of these two forms, only one, "L-aspartic acid", is directly incorporated into amino acids. The biological roles of its counterpart, "D-aspartic acid" are more limited. Where enzymatic synthesis will produce one or the other, most chemical syntheses will produce both forms, "DL-aspartic acid".

Role in biosynthesis of amino acids

Aspartate is non-essential in mammals, being produced from oxaloacetate by transamination. In plants and microorganisms, aspartate is the precursor to several amino acids, including four that are essential: methionine, threonine, isoleucine, and lysine. The conversion of aspartate to these other amino acids begins with reduction of aspartate to its "semialdehyde," O2CCH(NH2)CH2CHO.[4] Asparagine is derived from aspartate via transamidation:


(where GC(O)NH2 and GC(O)OH are glutamine and glutamic acid, respectively)

Other biochemical roles

Aspartate is also a metabolite in the urea cycle and participates in gluconeogenesis. It carries reducing equivalents in the malate-aspartate shuttle, which utilizes the ready interconversion of aspartate and oxaloacetate, which is the oxidized (dehydrogenated) derivative of malic acid. Aspartate donates one nitrogen atom in the biosynthesis of inosine, the precursor to the purine bases.


Aspartate (the conjugate base of aspartic acid) stimulates NMDA receptors, though not as strongly as the amino acid neurotransmitter glutamate does.[5] It serves as an excitatory neurotransmitter in the brain and is an excitotoxin.


Dietary sources

Aspartic acid is not an essential amino acid, which means that it can be synthesized from central metabolic pathway intermediates in humans. Aspartic acid is found in:

Chemical synthesis

Racemic aspartic acid can be synthesized from diethyl sodium phthalimidomalonate, (C6H4(CO)2NC(CO2Et)2).[6]


  1. 1.0 1.1 (1989) "862. Aspartic acid", The Merck Index, 11th, 132. ISBN 091191028X. 
  2. 2.0 2.1 Template:IUPAC-IUB amino acids 1983.
  3. R.H.A. Plimmer [1908] (1912). in R.H.A. Plimmer & F.G. Hopkins: The chemical composition of the proteins, 2nd, Monographs on biochemistry, London: Longmans, Green and Co., 112. Retrieved on January 18, 2010. 
  4. Template:Lehninger3rd.
  5. (2005) "Structural Features of the Glutamate Binding Site in Recombinant NR1/NR2A N-Methyl-D-aspartate Receptors Determined by Site-Directed Mutagenesis and Molecular Modeling". Mol. Pharmacol. 67 (5): 1470–84. doi:10.1124/mol.104.008185. PMID 15703381..
  6. (1950) "DL-Aspartic Acid". Org. Synth. 30: 7; Coll. Vol. 4: 55. .

See also

<tr bgcolor="#ccccff"><td colspan="3" align="center">
v  d  e
Major families of biochemicals</td></tr><tr><td colspan="3" style="text-align: center;">Peptides | Amino acids | Nucleic acids | Carbohydrates | Nucleotide sugars | Lipids | Terpenes | Carotenoids | Tetrapyrroles | Enzyme cofactors | Steroids | Flavonoids | Alkaloids | Polyketides | Glycosides</td></tr><tr bgcolor="pink"><td style="white-space: nowrap; width: 10%; color: pink;">Analogues of nucleic acids:</td><td align="center">The 20 Common Amino Acids ("dp" = data page)</td><td style="white-space: nowrap; width: 10%; color: pink;">Analogues of nucleic acids:</td></tr>
Alanine (dp) | Arginine (dp) | Asparagine (dp) | Aspartic acid (dp) | Cysteine (dp) | Glutamic acid (dp) | Glutamine (dp) | Glycine (dp) | Histidine (dp) | Isoleucine (dp) | Leucine (dp) | Lysine (dp) | Methionine (dp) | Phenylalanine (dp) | Proline (dp) | Serine (dp) | Threonine (dp) | Tryptophan (dp) | Tyrosine (dp) | Valine (dp)

Template:Neurotransmittersbn:অ্যাস্পার্টিক অ্যাসিড zh-min-nan:Asparagine sng ca:Àcid aspàrtic cs:Kyselina asparagová de:Asparaginsäureeo:Asparta acido eu:Azido aspartiko fa:اسید آسپارتیکga:Aigéad aspartach ko:아스파르트산 id:Asam aspartat it:Acido aspartico he:חומצה אספרטית lv:Asparagīnskābe lb:Aspartat lt:Asparto rūgštis hu:Aszparaginsav mk:Аспарагинска киселина nl:Asparaginezuurno:Asparaginsyre oc:Acid asparticsl:Asparaginska kislina sr:Asparaginska kiselina fi:Asparagiinihappo sv:Asparaginsyrauk:Аспарагінова кислота