Butanoic acid,2-[2-[4'-[2-[1-amino-8-hydroxy-3,6-disulfo-7-[2-(4-sulfophenyl)diazenyl]-2-naphthalenyl]diazenyl][1,1'-biphenyl]-4-yl]diazenyl]-3-oxo-,1-ethyl ester,sodium salt
Butanoic acid,2-[2-[4'-[2-[1-amino-8-hydroxy-3,6-disulfo-7-[2-(4-sulfophenyl)diazenyl]-2-naphthalenyl]diazenyl][1,1'-biphenyl]-4-yl]diazenyl]-3-oxo-,1-ethyl ester,sodium salt