SMILES: C1=CC2=C(C(=C1)Cl)NC=C2C(C(C3=CNC4=C3C=CC=C4Cl)C(=N)C(=O)O)C(=N)C(=O)O
Description: The molecule is a zwitterion that is derived from 3,4-bis(7-chloroindol-3-yl)-2,5-diiminohexanedioic acid by deprotonation of both carboxylic acid groups and protonation of both amino groups; major species at pH 7.3. It is a tautomer of a 3,4-bis(7-chloroindol-3-yl)-2,5-diiminohexanedioic acid.