Β-Leucine

β-Leucine (beta-leucine) is a beta amino acid and positional isomer of L-leucine which is naturally produced in humans via the metabolism of L-leucine by the enzyme leucine 2,3-aminomutase.^[1][2][3] In cobalamin (vitamin B₁₂) deficient individuals, plasma concentrations of β-leucine are elevated.^[3]

β-Leucine

Names
Preferred IUPAC name 3-Amino-4-methylpentanoic acid
Other names DL-β-Leucine; Homovaline
Identifiers
CAS Number	5699-54-7
3D model (JSmol)	Interactive image
ChEBI	CHEBI:15604
ChemSpider	167837
ECHA InfoCard	100.200.152
KEGG	C02486
PubChem CID	2761558
CompTox Dashboard (EPA)	DTXSID50863602
InChI InChI=1S/C6H13NO2/c1-4(2)5(7)3-6(8)9/h4-5H,3,7H2,1-2H3,(H,8,9) Key: GLUJNGJDHCTUJY-UHFFFAOYSA-N
SMILES CC(C)C(CC(=O)O)N
Properties
Chemical formula	C6H13NO2
Molar mass	131.175 g·mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Biosynthesis and metabolism in humans

A small fraction of L-leucine metabolism – less than 5% in all tissues except the testes where it accounts for about 33% – is initially catalyzed by leucine aminomutase, producing β-leucine, which is subsequently metabolized into β-ketoisocaproate (β-KIC), β-ketoisocaproyl-CoA, and then acetyl-CoA by a series of uncharacterized enzymes.^[1][2]

References

1. Kohlmeier M (May 2015). "Leucine". Nutrient Metabolism: Structures, Functions, and Genes (2nd ed.). Academic Press. pp. 385–388. ISBN 978-0-12-387784-0. Archived from the original on 22 March 2018. Retrieved 6 June 2016. Energy fuel: Eventually, most Leu is broken down, providing about 6.0kcal/g. About 60% of ingested Leu is oxidized within a few hours ... Ketogenesis: A significant proportion (40% of an ingested dose) is converted into acetyl-CoA and thereby contributes to the synthesis of ketones, steroids, fatty acids, and other compounds
   Figure 8.57: Metabolism of L-leucine Archived 22 March 2018 at the Wayback Machine
2. "Leucine metabolism". BRENDA. Technische Universität Braunschweig. Archived from the original on 17 August 2016. Retrieved 12 August 2016.
3. "Human Metabolome Database: Showing metabocard for Beta-Leucine (HMDB0003640)".