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Record Information
StatusDetected and Quantified
Creation Date2006-05-22 14:17:39 UTC
Update Date2017-10-23 19:03:57 UTC
Secondary Accession Numbers
  • HMDB02166
Metabolite Identification
Common Name(S)-b-aminoisobutyric acid
DescriptionBeta-Aminoisobutyric acid is a non-protein amino acid originating from the catabolism of thymine and valine. The concentration of beta-Aminoisobutyric acid is normally low in urine as beta-Aminoisobutyric acid is further catabolized by b-aminoisobutyrate aminotransferases to methylmalonic acid semialdehyde and propionyl-CoA. beta-Aminoisobutyric acid occurs in two isomeric forms and both enantiomers of beta-Aminoisobutyric acid can be detected in human urine and plasma. In plasma, the S-enantiomer is the predominant type due to active renal reabsorption. In contrast, urine almost exclusively contains the R-enantiomer of beta-Aminoisobutyric acid, which is eliminated both by filtration and tubular secretion. Persistently increased levels of beta-Aminoisobutyric acid have been observed in individuals with a deficiency of R (-) -b-aminoisobutyrate-pyruvate aminotransferase. In addition, transient high levels of beta-Aminoisobutyric acid have been observed under a variety of pathological conditions such as lead poisoning, starvation, in total body irradiation and in a number of malignancies. The S-enantiomer of beta-Aminoisobutyric acid is predominantly derived from the catabolism of valine. It has been suggested that an altered homoeostasis of b-alanine underlies some of the clinical abnormalities encountered in patients with a dihydropyrimidine dehydrogenase (DPD) deficiency. DPD constitutes the first step of the pyrimidine degradation pathway, in which the pyrimidine bases uracil and thymine are catabolized to b-alanine and the R-enantiomer of beta-Aminoisobutyric acid respectively. In normal individuals with an intact pyrimidine degradation pathway, R-methylmalonic acid semialdehyde can be synthesized directly from the catabolism of thymine. Hence, there might be less cross-over between the valine and thymine pathway, allowing the conversion of S-methylmalonic acid semialdehyde into S-beta-Aminoisobutyric acid and the subsequent accumulation of S-beta-Aminoisobutyric acid in plasma. (PMID: 14705962 , 14292857 , 14453202 ).
SynonymsNot Available
Chemical FormulaC4H9NO2
Average Molecular Weight103.1198
Monoisotopic Molecular Weight103.063328537
IUPAC NameNot Available
Traditional NameNot Available
CAS Registry Number4249-19-8
SMILESNot Available
InChI Identifier
Chemical Taxonomy
ClassificationNot classified

Naturally occurring process:

  Biological process:

    Biochemical pathway:


Biological Location:

  Biofluid and excreta:


Physical Properties
Experimental Properties
Melting Point175 - 177 °CNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted PropertiesNot Available
Spectrum TypeDescriptionSplash Key
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-001i-9000000000-59e52601f90d8e636d61View in MoNA
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (1 TMS) - 70eV, Positivesplash10-00ar-9200000000-0eb92539979a9fa36dbdView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-0f79-9300000000-30669ed04aadf3d3f040View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-000l-9000000000-ca65637476e64152c44eView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0006-9000000000-04d1648391d3f90db226View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-0udi-3900000000-ec54fcce079024a62344View in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-0zfr-9500000000-0394f399cdf5df93c5dfView in MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-0a4l-9000000000-d0c495c908ed905558a2View in MoNA
Biological Properties
Cellular LocationsNot Available
Biofluid Locations
  • Blood
  • Feces
  • Urine
Tissue LocationNot Available
2-Methyl-3-Hydroxybutryl CoA Dehydrogenase DeficiencyPw000061Pw000061 greyscalePw000061 simpleNot Available
3-Hydroxy-3-Methylglutaryl-CoA Lyase DeficiencyPw000063Pw000063 greyscalePw000063 simpleNot Available
3-Methylcrotonyl Coa Carboxylase Deficiency Type IPw000065Pw000065 greyscalePw000065 simpleNot Available
3-Methylglutaconic Aciduria Type IPw000066Pw000066 greyscalePw000066 simpleNot Available
3-Methylglutaconic Aciduria Type IIIPw000067Pw000067 greyscalePw000067 simpleNot Available
Displaying entries 1 - 5 of 17 in total
Normal Concentrations
BloodDetected and Quantified1.03 +/- 0.34 uMAdult (>18 years old)MaleNormal
    • Geigy Scientific ...
FecesDetected but not Quantified Not SpecifiedNot Specified
FecesDetected but not Quantified Adult (>18 years old)Both
UrineDetected and Quantified7.0 +/- 6.6 umol/mmol creatinineAdult (>18 years old)FemaleNormal
    • Geigy Scientific ...
UrineDetected and Quantified10.0 +/- 9.0 umol/mmol creatinineAdult (>18 years old)MaleNormal
    • Geigy Scientific ...
    • West Cadwell, N.J...
    • Basel, Switzerlan...
UrineDetected and Quantified4.3 +/- 2.9 umol/mmol creatinineChildren (1-13 years old)BothNormal
    • Geigy Scientific ...
    • West Cadwell, N.J...
    • Basel, Switzerlan...
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
DrugBank Metabolite IDNot Available
Phenol Explorer Compound IDNot Available
Phenol Explorer Metabolite IDNot Available
FoodDB IDFDB022878
KNApSAcK IDNot Available
Chemspider ID388543
KEGG Compound IDC03284
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkNot Available
PubChem Compound439434
PDB IDNot Available
ChEBI ID33094
Synthesis ReferenceAlauddin, Mian M.; Fissekis, John D.; Conti, Peter S. a-Alkylation of amino acid derivatives: synthesis and chiral resolution of [11C]b-aminoisobutyric acid. Nuclear Medicine and Biology (1997), 24(8), 771-775.
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Van Kuilenburg AB, Stroomer AE, Van Lenthe H, Abeling NG, Van Gennip AH: New insights in dihydropyrimidine dehydrogenase deficiency: a pivotal role for beta-aminoisobutyric acid? Biochem J. 2004 Apr 1;379(Pt 1):119-24. [PubMed:14705962 ]
  2. Roe CR, Struys E, Kok RM, Roe DS, Harris RA, Jakobs C: Methylmalonic semialdehyde dehydrogenase deficiency: psychomotor delay and methylmalonic aciduria without metabolic decompensation. Mol Genet Metab. 1998 Sep;65(1):35-43. [PubMed:9787093 ]
  3. KAKIMOTO Y, KANAZAWA A, SANO I: IDENTIFICATION OF D(-)-BETA-AMINOISOBUTYRIC ACID IN HUMAN LIVER. Biochim Biophys Acta. 1965 Feb 15;97:376-7. [PubMed:14292857 ]
  4. KAKIMOTO Y, ARMSTRONG MD: The preparation and isolation of D-(-)-beta-aminoisobutyric acid. J Biol Chem. 1961 Dec;236:3283-6. [PubMed:14453202 ]


General function:
Involved in 4-aminobutyrate transaminase activity
Specific function:
Catalyzes the conversion of gamma-aminobutyrate and L-beta-aminoisobutyrate to succinate semialdehyde and methylmalonate semialdehyde, respectively. Can also convert delta-aminovalerate and beta-alanine.
Gene Name:
Uniprot ID:
Molecular weight:
(S)-b-aminoisobutyric acid + Oxoglutaric acid → 2-Methyl-3-oxopropanoic acid + L-Glutamic aciddetails
(S)-b-aminoisobutyric acid + Oxoglutaric acid → (S)-Methylmalonic acid semialdehyde + L-Glutamic aciddetails