Indole-3-pyruvate
= Indole-3-pyruvate
\b[Indole-3-pyruvate] is the <indole>-substituted pyruvate anion named systematically 3-(1H-indol-3-yl)-2-oxopropanoate. It is the <conjugate base> of <indole-3-pyruvic acid>. The three-carbon side chain distinguishes it from <indole-3-acetate>, whose corresponding side chain has two carbons.<Enzyme Nomenclature by the IUBMB>[EC1.14.13.168, substrate and product Glossary.]{ref}
A biological example is the plant route from <tryptophan> to the <auxin> <indole-3-acetate>. A <transamination> supplies <indole-3-pyruvate>; a <YUCCA flavin monooxygenase> then participates in its conversion to <indole-3-acetate>. The accepted net reaction uses <NADPH> and <molecular oxygen> and releases <carbon dioxide>, so the step is not simply a change in protonation.<Enzyme Nomenclature by the IUBMB>[EC1.14.13.168, Reaction and Comments; linked EC2.6.1.99.]{ref}
An original carbon inventory makes the one-carbon loss clear. The indole framework contributes eight carbon atoms, giving eleven in <indole-3-pyruvate> and ten in <indole-3-acetate>. Converting 20 nmol of substrate according to the stated reaction distributes $20(11)=220$ nmol of carbon atoms between $20(10)=200$ nmol in the organic product and 20 nmol in <carbon dioxide>. The balance checks the net <stoichiometry>, without establishing the provenance of individual oxygen atoms or a reaction rate.