disodium 5-[[2,4-dihydroxy-3-[(2-hydroxy-5-nitrophenyl)azo]-5-[(4-nitrophenyl)azo]phenyl]azo]-4-hydroxy-3-[(4-nitrophenyl)azo]naphthalene-2,7-disulphonate

5-[[2,4-Dihydroxy-3-[(2-hydroxy-5-nitrophenyl)azo]-5-[(4-nitrophenyl)azo]phenyl]azo]-4-hydroxy-3-[(4-nitrophenyl)azo]-2,7-naphthalenedisulfonic acid disodium salt