The molecule is a monocarboxylic acid anion that is the conjugate base of 3-indoleacrylic acid, obtained by deprotonation of the carboxy group; major species at pH 7.3. It is a conjugate base of an (E)-3-(indol-3-yl)acrylic acid.
(E)-3-(1H-indol-3-yl)prop-2-enoate