disodium 6-[[4-hydroxy-3-[[[2-(methyloctadecylamino)-5-sulphonatophenyl]amino]carbonyl]-1-naphthyl]azo]naphthalene-2-sulphonate

6-[[4-Hydroxy-3-[[2-(methyloctadecylamino)-5-[(sodiooxy)sulfonyl]phenyl]carbamoyl]naphthalen-1-yl]azo]-2-naphthalenesulfonic acid sodium salt