Alloisoleucine is an amino acid with the formula . It is the diastereomer of isoleucine, differing in the stereochemistry within the side chain. Alloisoleucine exists as two enantiomers, of which the L isomer occurs naturally. L-Alloisoleucine occurs in healthy serum in only trace amounts, except for individuals suffering from maple syrup urine disease.
Structure Together with valine, leucine, and isoleucine, alloisoleucine is classified as a branched-chain amino acid (BCAA). The L enantiomer of valine, leucine, and isoleucine are proteinogenic amino acids; alloisoleucine is non-proteinogenic.
-isoleucine (2S,3S) and -isoleucine (2R,3R) -alloisoleucine (2S,3R) and -alloisoleucine (2R,3S)
Role in biosynthesis L-Alloisoleucine is a precursor to coronatine, a phytotoxin produced by Pseudomonas syringae.
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