The molecule is a monocarboxylic acid anion that is the conjugate base of protoviolaceinic acid, resulting from the removal of the proton from the carboxy group. Major structure at pH 7.3. It is a conjugate base of a protoviolaceinic acid.
3-[5-carboxy-4-(1H-indol-3-yl)-1H-pyrrol-2-yl]-1H-indol-5-olate