2,3,4,5-Tetrachloro-4',5'-dihydroxy-fluorescein 2,3,4,5-Tetrachloro-6-(3',4',5',6'-tetrahydroxy-9H-yl)-benzoic acid 2,3,4,5-Tetrachloro-gallain 9-(6-carboxy-2',3',4',5'-tetrachloro-phenyl)-3,4,5,6-tetrahydroxy-xanthylium NSC723402