The molecule is an amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 4-(3-methylbut-2-enyl)-L-tryptophan; major species at pH 7.3. It is a tautomer of a 4-(3-methylbut-2-enyl)-L-tryptophan.
(2S)-2-azaniumyl-3-[4-(3-methylbut-2-enyl)-1H-indol-3-yl]propanoate