The molecule is an indol-3-yl carboxylic acid anion resulting from the deprotonation of the carboxy group of 2-hydroxy-(indol-3-yl)acetic acid. This is a very minor tautomer; the major tautomer is the corresponding oxindole. It is a conjugate base of a 2-hydroxy-(indol-3-yl)acetic acid.
2-(2-hydroxy-1H-indol-3-yl)acetate