29773-26-0 BRN 2229536 Butanoic acid, 2-(((4-(((carboxymethyl)amino)carbonyl)-2,3,5,6-tetraiodobenzoyl)amino)methyl)- alpha-(4-(Carboxymethyl-carbamoyl)-2,3,5,6-tetrajod-benzoylamidomethyl)-buttersaure [German]