WARNING: This product is for research use only, not for human or veterinary use.

MedKoo CAT#: 620106

CAS#: 1509-34-8

Description: L-allo-Isoleucine may be used in studies on maple syrup urine disease (MSUD). In patients with classical MSUD (n = 7), alloisoleucine was beyond the cutoff value in 2451 of 2453 unselected samples. In patients with variant MSUD (n = 9), alloisoleucine was >5 micromol/L in all samples taken for establishment of diagnosis and in 94% of the samples taken for treatment control (n = 624). With the other branched-chain amino acids, the frequency of diagnostically significant increases was <45%. The plasma L-alloisoleucine above the cutoff value of 5 micromol/L is the most specific and most sensitive diagnostic marker for all forms of MSUD.

Chemical Structure

CAS# 1509-34-8

Theoretical Analysis

MedKoo Cat#: 620106
Name: L-allo-Isoleucine
CAS#: 1509-34-8
Chemical Formula: C6H13NO2
Exact Mass: 131.0946
Molecular Weight: 131.175
Elemental Analysis: C, 54.94; H, 9.99; N, 10.68; O, 24.39

Price and Availability

Size Price Availability Quantity
25.0mg USD 90.0 2 Weeks
50.0mg USD 120.0 2 Weeks
100.0mg USD 150.0 2 Weeks
200.0mg USD 250.0 2 Weeks
500.0mg USD 450.0 2 Weeks
1.0g USD 650.0 2 Weeks
2.0g USD 1050.0 2 Weeks
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Synonym: L-allo-Isoleucine; L-alloIsoleucine.

IUPAC/Chemical Name: (2S,3R)-2-Amino-3-methylpentanoic acid


InChi Code: InChI=1S/C6H13NO2/c1-3-4(2)5(7)6(8)9/h4-5H,3,7H2,1-2H3,(H,8,9)/t4-,5+/m1/s1

SMILES Code: CC[C@@H](C)[C@H](N)C(O)=O

Appearance: Solid powder

Purity: >98% (or refer to the Certificate of Analysis)

Shipping Condition: Shipped under ambient temperature as non-hazardous chemical. This product is stable enough for a few weeks during ordinary shipping and time spent in Customs.

Storage Condition: Dry, dark and at 0 - 4 C for short term (days to weeks) or -20 C for long term (months to years).

Solubility: Soluble in DMSO, not in water

Shelf Life: >2 years if stored properly

Drug Formulation: This drug may be formulated in DMSO

Stock Solution Storage: 0 - 4 C for short term (days to weeks), or -20 C for long term (months).

HS Tariff Code: 2934.99.9001

Preparing Stock Solutions

The following data is based on the product molecular weight 131.175 Batch specific molecular weights may vary from batch to batch due to the degree of hydration, which will affect the solvent volumes required to prepare stock solutions.

Recalculate based on batch purity %
Concentration / Solvent Volume / Mass 1 mg 5 mg 10 mg
1 mM 1.15 mL 5.76 mL 11.51 mL
5 mM 0.23 mL 1.15 mL 2.3 mL
10 mM 0.12 mL 0.58 mL 1.15 mL
50 mM 0.02 mL 0.12 mL 0.23 mL

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1: Rodrigues KT, Mekahli D, Tavares MF, Van Schepdael A. Development and validation of a CE-MS method for the targeted assessment of amino acids in urine. Electrophoresis. 2016 Apr;37(7-8):1039-47. doi: 10.1002/elps.201500534. Epub 2016 Feb 25. PubMed PMID: 26826549.

2: Ryan RO. Metabolic annotation of 2-ethylhydracrylic acid. Clin Chim Acta. 2015 Aug 25;448:91-7. doi: 10.1016/j.cca.2015.06.012. Epub 2015 Jun 23. Review. PubMed PMID: 26115894; PubMed Central PMCID: PMC4618168.

3: Jeong JS, Sim HJ, Lee YM, Yoon HR, Kwon HJ, Hong SP. Chromatographic diagnosis of maple syrup urine disease by measuring the L-alloisoleucine/L-phenylalanine ratio in dried blood spots. J Chromatogr B Analyt Technol Biomed Life Sci. 2011 Jul 15;879(22):2171-4. doi: 10.1016/j.jchromb.2011.05.023. Epub 2011 May 23. PubMed PMID: 21680261.

4: Kato S, Oba Y, Ojika M, Inouye S. Stereoselective incorporation of isoleucine into Cypridina luciferin in Cypridina hilgendorfii (Vargula hilgendorfii). Biosci Biotechnol Biochem. 2006 Jun;70(6):1528-32. PubMed PMID: 16794342.

5: Bodner-Leidecker A, Wendel U, Saudubray JM, Schadewaldt P. Branched-chain L-amino acid metabolism in classical maple syrup urine disease after orthotopic liver transplantation. J Inherit Metab Dis. 2000 Dec;23(8):805-18. PubMed PMID: 11196106.

6: Schadewaldt P, Bodner-Leidecker A, Hammen HW, Wendel U. Formation of L-alloisoleucine in vivo: an L-[13C]isoleucine study in man. Pediatr Res. 2000 Feb;47(2):271-7. PubMed PMID: 10674358.

7: Schadewaldt P, Bodner-Leidecker A, Hammen HW, Wendel U. Significance of L-alloisoleucine in plasma for diagnosis of maple syrup urine disease. Clin Chem. 1999 Oct;45(10):1734-40. PubMed PMID: 10508118.

8: Mamer OA, Lépine FL. 15N conservation in the metabolic conversion of isoleucine to alloisoleucine in the rat. J Mass Spectrom. 1996 Dec;31(12):1382-8. PubMed PMID: 8990521.

9: Schadewaldt P, Wendel U, Hammen HW. Determination of R- and S-3-methyl-2-oxopentanoate enantiomers in human plasma: suitable method for label enrichment analysis. J Chromatogr B Biomed Appl. 1996 Jul 12;682(2):209-18. PubMed PMID: 8844412.

10: Hall TR, Wallin R, Reinhart GD, Hutson SM. Branched chain aminotransferase isoenzymes. Purification and characterization of the rat brain isoenzyme. J Biol Chem. 1993 Feb 15;268(5):3092-8. PubMed PMID: 8381418.

11: Gibson KM, Lee CF, Bennett MJ, Holmes B, Nyhan WL. Combined malonic, methylmalonic and ethylmalonic acid semialdehyde dehydrogenase deficiencies: an inborn error of beta-alanine, L-valine and L-alloisoleucine metabolism? J Inherit Metab Dis. 1993;16(3):563-7. PubMed PMID: 7609453.

12: Mamer OA, Reimer ML. On the mechanisms of the formation of L-alloisoleucine and the 2-hydroxy-3-methylvaleric acid stereoisomers from L-isoleucine in maple syrup urine disease patients and in normal humans. J Biol Chem. 1992 Nov 5;267(31):22141-7. PubMed PMID: 1429566.

13: Wendel U, Even G, Langenbeck U, Schadewaldt P, Hummel W. Determination of (S)- and (R)-2-oxo-3-methylvaleric acid in plasma of patients with maple syrup urine disease. Clin Chim Acta. 1992 Jun 15;208(1-2):85-91. PubMed PMID: 1638756.

14: Schadewaldt P, Dalle-Feste C, Langenbeck U, Wendel U. Oral L-alloisoleucine loading studies in healthy subjects and in patients with maple syrup urine disease. Pediatr Res. 1991 Nov;30(5):430-4. PubMed PMID: 1754297.

15: Schadewaldt P, Hammen HW, Dalle-Feste C, Wendel U. On the mechanism of L-alloisoleucine formation: studies on a healthy subject and in fibroblasts from normals and patients with maple syrup urine disease. J Inherit Metab Dis. 1990;13(2):137-50. PubMed PMID: 2116545.

16: Schadewaldt P, Radeck W, Hammen HW, Staib W. Transamination and oxidative decarboxylation of L-isoleucine, L-alloisoleucine and related 2-oxo acids in perfused rat hind limb muscle. Biochim Biophys Acta. 1989 Jul 21;992(1):115-23. PubMed PMID: 2568853.

17: Downey RS, Karl IE, Bier DM. Branched-chain amino acid interactions in skeletal muscle: isoleucine and L-alloisoleucine. JPEN J Parenter Enteral Nutr. 1986 Sep-Oct;10(5):456-62. PubMed PMID: 3093701.

18: Matthews DE, Ben-Galim E, Haymond MW, Bier DM. Alloisoleucine formation in maple syrup urine disease: isotopic evidence for the mechanism. Pediatr Res. 1980 Jul;14(7):854-7. PubMed PMID: 7413299.

19: Yajima T, Mason K, Katz E. Biogenetic origin of the D-isoleucine and N-methyl-L-alloisoleucine residues in the actinomycins. Antimicrob Agents Chemother. 1976 Feb;9(2):224-32. PubMed PMID: 57739; PubMed Central PMCID: PMC429508.