72906-19-5 Cuprate(1-), (3-((((3-amino-4-nitrophenyl)azo)-2,4-dihydroxyphenyl)azo)-4-hydroxybenzenesulfonato(3-))-, sodium Cuprate(1-), (3-((((3-amino-4-nitrophenyl)azo)-2-(hydroxy-kappaO)-4-hydroxyphenyl)azo-kappaN1)-4-(hydroxy-kappaO)benzenesulfonato(3-))-, sodium