Alloisoleucine

Alloisoleucine is an amino acid with the formula CH₃CH₂CH(CH₃)CH(NH₂)CO₂H. It exists as two enantiomers, of which the L derivative occurs naturally. L-Alloisoleucine occurs in healthy serum in only trace amounts, except for individuals suffering from maple syrup urine disease.^[1]

Alloisoleucine

Identifiers
CAS Number	L-enantiomer: 1509-35-8 D enantiomer: 1509-34-9 racemic: 3107-04-8
3D model (JSmol)	L-enantiomer: Interactive image D enantiomer: Interactive image racemic: Interactive image
Beilstein Reference	1721791
ChEBI	L-enantiomer: CHEBI:43433 D enantiomer: CHEBI:20899
ChEMBL	L-enantiomer: ChEMBL56053
ChemSpider	L-enantiomer: 89698 D enantiomer: 85019
DrugBank	L-enantiomer: DB01739
ECHA InfoCard	100.014.676
EC Number	L-enantiomer: 216-142-3 racemic: 207-139-8
PubChem CID	L-enantiomer: 99288 D enantiomer: 94206
UNII	L-enantiomer: 6RNR8XN7S2 racemic: 05T3WT3PJ1
CompTox Dashboard (EPA)	L-enantiomer: DTXSID901019590
InChI 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 Key: AGPKZVBTJJNPAG-UHNVWZDZSA-N D enantiomer: InChI=1S/C6H13NO2/c1-3-4(2)5(7)6(8)9/h4-5H,3,7H2,1-2H3,(H,8,9)/t4-,5+/m0/s1 Key: AGPKZVBTJJNPAG-CRCLSJGQSA-N
SMILES L-enantiomer: CC[C@@H](C)[C@@H](C(=O)O)N D enantiomer: CC[C@H](C)[C@H](C(=O)O)N racemic: CCC(C)C(C(=O)O)N
Properties
Appearance	white solid
Melting point	285 °C (545 °F; 558 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Structure

Together with valine, leucine, and isoleucine, alloisoleucine is classified as a branched-chain amino acid (BCAA). It is the rarest of the four.

L-Alloisoleucine is a diastereomer of the proteogenic amino acid L-isoleucine. The stereochemistry of the isobutyl group differs for L-alloisoleucine and L-isoleucine.

l-isoleucine (2S,3S) and d-isoleucine (2R,3R)

l-alloisoleucine (2S,3R) and d-alloisoleucine (2R,3S)

Role in biosynthesis

L-allo-isoleucine is a precursor to coronamic acid, which is a constituent of the phytotoxin coronatine, produced by Pseudomonas syringae.^[2]

References

1. Schadewaldt, Peter; Bodner-Leidecker, Annette; Hammen, Hans-Werner; Wendel, Udo (2000). "Formation of L-Alloisoleucine in Vivo : An L-[13C]Isoleucine Study in Man". Pediatric Research. 47 (2): 271–277. doi:10.1203/00006450-200002000-00020. PMID 10674358. S2CID 530588.
2. Vaillancourt, Frédéric H.; Yeh, Ellen; Vosburg, David A.; O'Connor, Sarah E.; Walsh, Christopher T. (August 2005). "Cryptic chlorination by a non-haem iron enzyme during cyclopropyl amino acid biosynthesis". Nature. 436 (7054): 1191–1194. Bibcode:2005Natur.436.1191V. doi:10.1038/nature03797. ISSN 1476-4687. PMID 16121186. S2CID 4428247.