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Record Information
StatusDetected and Quantified
Creation Date2006-08-13 02:23:00 UTC
Update Date2019-07-23 05:45:51 UTC
Secondary Accession Numbers
  • HMDB03640
Metabolite Identification
Common NameBeta-Leucine
DescriptionBeta-leucine is a metabolite that is in the middle of a controversy over its presence in the human body. While there are reports that claim it as a human metabolite, there are others that deny its existence. Two examples:. Circulating levels of beta-leucine are elevated in the cobalamin-deficient state of pernicious anemia. Levels of leucine, on the other hand, are much lower. It is proposed that leucine 2,3-aminomutase, the cobalamin-dependent enzyme that catalyzes the interconversion of leucine and beta-leucine, is the affected enzyme in pernicious anemia and causes these results by preventing the synthesis of leucine from beta-leucine. The synthesis of leucine by human leukocytes and hair roots and by rat liver extracts has been shown to occur when either branched chain fatty acids or valine metabolites are the substances. The synthesis is dependent upon adenosylcobalamin and is inhibited by intrinsic factor (PMID: 7430116 ). Using forms of beta-leucine and leucine that contain several deuterium atoms in place of several hydrogen atoms as internal standards, techniques have been developed which make it possible to detect and quantitate as little as 0.1 mumol/liter of beta-leucine or leucine in human serum and in incubations containing rat liver supernatant. beta-Leucine was not detectable, i.e. less than 0.1 mumol/liter, in any sera from 50 normal human subjects or in any sera from 50 cobalamin-deficient patients. Experiments in which beta-leucine, leucine, isostearic acid, or isocaproic acid were incubated with rat liver supernatant in the presence or absence of adenosylcobalamin or cobalamin-binding protein failed to demonstrate the formation of leucine or beta-leucine or their interconversion under any of the conditions studied. We conclude that beta-leucine is not present in human blood and that the existence of leucine 2,3-aminomutase in mammalian tissues remains to be established (PMID 3356699 ). Beta-leucine is found to be associated with cobalamin deficiency, which is an inborn error of metabolism.
beta-2-Amino-4-methylvaleric acidHMDB
3-Amino-4-methylpentanoic acidHMDB
Chemical FormulaC6H13NO2
Average Molecular Weight131.1729
Monoisotopic Molecular Weight131.094628665
IUPAC Name(3S)-3-amino-4-methylpentanoic acid
Traditional Nameβ-leucine
CAS Registry Number5699-54-7
InChI Identifier
Chemical Taxonomy
Description belongs to the class of organic compounds known as beta amino acids and derivatives. These are amino acids having a (-NH2) group attached to the beta carbon atom.
KingdomOrganic compounds
Super ClassOrganic acids and derivatives
ClassCarboxylic acids and derivatives
Sub ClassAmino acids, peptides, and analogues
Direct ParentBeta amino acids and derivatives
Alternative Parents
  • Beta amino acid or derivatives
  • Amino fatty acid
  • Branched fatty acid
  • Methyl-branched fatty acid
  • Fatty acyl
  • Fatty acid
  • Amino acid
  • Carboxylic acid
  • Monocarboxylic acid or derivatives
  • Amine
  • Primary amine
  • Organooxygen compound
  • Organonitrogen compound
  • Hydrocarbon derivative
  • Primary aliphatic amine
  • Organic oxide
  • Carbonyl group
  • Organopnictogen compound
  • Organic oxygen compound
  • Organic nitrogen compound
  • Aliphatic acyclic compound
Molecular FrameworkAliphatic acyclic compounds
External Descriptors
Physiological effect

Health effect:


Biological location:


Physical Properties
Experimental Properties
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogP0.778Not Available
Predicted Properties
Water Solubility126 g/LALOGPS
pKa (Strongest Acidic)4.39ChemAxon
pKa (Strongest Basic)10.6ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area63.32 ŲChemAxon
Rotatable Bond Count3ChemAxon
Refractivity34.12 m³·mol⁻¹ChemAxon
Polarizability14.07 ųChemAxon
Number of Rings0ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-000i-9000000000-b4ef4716fcf2c24852fdJSpectraViewer | MoNA
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (1 TMS) - 70eV, Positivesplash10-00di-9200000000-e6038fb7fedb2b592622JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 10V, N/A (Annotated)splash10-00di-9200000000-c312d7b4661374b11fe7JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 25V, N/A (Annotated)splash10-05fu-9000000000-2f3a81db4c2c8d6143a2JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - Quattro_QQQ 40V, N/A (Annotated)splash10-0a4l-9000000000-0b2e4113ec38ca7843a1JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 10V, Positivesplash10-001i-2900000000-5c08508080e2ead24ed1JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 20V, Positivesplash10-00di-9100000000-e86097bd64d6da7ab50eJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 30V, Positivesplash10-00di-9000000000-8f051218b3e657e92beeJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 40V, Positivesplash10-0ab9-9000000000-58d7d5408744e17b8aa9JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ (API3000, Applied Biosystems) 50V, Positivesplash10-0a4l-9000000000-918d253495faf90f8c96JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-001i-2900000000-5c08508080e2ead24ed1JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00di-9100000000-e86097bd64d6da7ab50eJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-00di-9000000000-8f051218b3e657e92beeJSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-0ab9-9000000000-ed73d8f252611f502b47JSpectraViewer | MoNA
LC-MS/MSLC-MS/MS Spectrum - LC-ESI-QQ , positivesplash10-0a4l-9000000000-918d253495faf90f8c96JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-03di-3900000000-1f2691c9c25f658b63feJSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-0cka-9400000000-c0d4b51d8c4fce50aedeJSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-0avl-9000000000-437c8e5e44bc9466d6edJSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-001i-3900000000-f8aa929f8a383bc99d23JSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-01q0-6900000000-e97f92ca9178bdecdf5cJSpectraViewer | MoNA
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-00y0-9100000000-5664de291dd8fa5bc277JSpectraViewer | MoNA
1D NMR1H NMR SpectrumNot AvailableJSpectraViewer
2D NMR[1H,13C] 2D NMR SpectrumNot AvailableJSpectraViewer
Biological Properties
Cellular LocationsNot Available
Biospecimen Locations
  • Blood
Tissue LocationsNot Available
Normal Concentrations
BloodDetected and Quantified4.8 (2.0-8.0) uMAdult (>18 years old)BothNormal details
Abnormal Concentrations
BloodDetected and Quantified24.7 (10.0-50.0) uMAdult (>18 years old)BothCobalamin deficiency details
Associated Disorders and Diseases
Disease References
Vitamin B12 deficiency
  1. Stabler SP, Lindenbaum J, Allen RH: Failure to detect beta-leucine in human blood or leucine 2,3-aminomutase in rat liver using capillary gas chromatography-mass spectrometry. J Biol Chem. 1988 Apr 25;263(12):5581-8. [PubMed:3356699 ]
Associated OMIM IDsNone
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FoodDB IDFDB023208
KNApSAcK IDNot Available
Chemspider ID388796
KEGG Compound IDC02486
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkΒ-Leucine
METLIN IDNot Available
PubChem Compound439734
PDB IDNot Available
ChEBI ID86261
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Poston JM: Cobalamin-dependent formation of leucine and beta-leucine by rat and human tissue. Changes in pernicious anemia. J Biol Chem. 1980 Nov 10;255(21):10067-72. [PubMed:7430116 ]
  2. Stabler SP, Lindenbaum J, Allen RH: Failure to detect beta-leucine in human blood or leucine 2,3-aminomutase in rat liver using capillary gas chromatography-mass spectrometry. J Biol Chem. 1988 Apr 25;263(12):5581-8. [PubMed:3356699 ]