Acid red 431

4-Hydroxy-7-[[4-[2-(4-nitro-2-sulfophenyl)ethenyl]-3-sulfophenyl]azo]-3-[[2-sulfo-4-[(4-sulfophenyl)azo]phenyl]azo]-2-naphthalenesulfonic acid pentasodium salt

pentasodium 4-hydroxy-7-[[4-[2-(4-nitro-2-sulphonatophenyl)vinyl]-3-sulphonatophenyl]azo]-3-[[2-sulphonato-4-[(4-sulphonatophenyl)azo]phenyl]azo]naphthalene-2-sulphonate