4-Amino-5-hydroxy-6-[[4'-[(4-hydroxyphenyl)azo]-3,3'-dimethyl-1,1'-biphenyl-4-yl]azo]-3-[(4-nitrophenyl)azo]-2,7-naphthalenedisulfonic acid

4-amino-5-hydroxy-6-[[4'-[(4-hydroxyphenyl)azo]-3,3'-dimethyl[1,1'-biphenyl]-4-yl]azo]-3-[(4-nitrophenyl)azo]naphthalene-2,7-disulphonic acid