trisodium 5-[[2,4-dihydroxy-5-[[4-[(4-nitro-2-sulphonatophenyl)amino]phenyl]azo]phenyl]azo]-4-hydroxy-3-[(4-methoxyphenyl)azo]naphthalene-2,7-disulphonate

5-[[2,4-Dihydroxy-5-[[4-[4-nitro-2-[(sodiooxy)sulfonyl]anilino]phenyl]azo]phenyl]azo]-4-hydroxy-3-[(4-methoxyphenyl)azo]-2,7-naphthalenedisulfonic acid disodium salt