sodium 1-methyl 2-[[4-hydroxy-3-[[[2-(methyloctadecylamino)-5-sulphonatophenyl]amino]carbonyl]-1-naphthyl]azo]-5-[1-(4-hydroxyphenyl)-1-methylethyl]benzoate

2-[[4-Hydroxy-3-[[[2-[methyl(octadecyl)amino]-5-[(sodiooxy)sulfonyl]phenyl]amino]carbonyl]-1-naphthalenyl]azo]-5-[1-(4-hydroxyphenyl)-1-methylethyl]benzoic acid methyl ester