Synonyms: Benzenesulfonic acid, 2-(4,5,6-trihydroxy-3-oxo-3H-xanthen-9-yl)-;Spiro(3H-2,1-benzoxathiole-3,9'-(9H)xanthene)-3',4',5',6'-tetrol, 1,1-dioxide;spiro[2,1-benzoxathiole-3,9'-xanthene]-3',4',5',6'-tetrol 1,1-dioxide;2-(4,5,6-trihydroxy-3-oxo-3H-xanthen-9-yl)benzenesulfonic acid;2-(4,5,6-trihydroxy-3-oxo-3H-xanthen-9-yl)benzenesulfonate