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-abrine. It is a tautomer of a 4-(3-methylbut-2-enyl)-L-abrine.
(2S)-2-(methylazaniumyl)-3-[4-(3-methylbut-2-enyl)-1H-indol-3-yl]propanoate