3,4-dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-sulfonic acid;NSC 56653;1,2-Dihydroxy-9,10-dihydro-9,10-dioxoanthracene-3-sulfonic acid;1,2-Dihydroxy-9,10-dioxo-9,10-dihydroanthracene-3-sulfonic acid;3-Alizarinsulfonic acid;Alizarin Red S free acid;1,2