Interactions of 1-(6-((13-(3-((1,7-bis((1,5-dicarboxy-3-(2-carboxyethyl)pentan-3-yl)amino)-4-(3-((1,5-dicarboxy-3-(2-carboxyethyl)pentan-3-yl)amino)-3-oxopropyl)-1,7-dioxoheptan-4-yl)amino)-3-oxopropyl)-1,25-dicarboxy-3,3,23,23-tetrakis(2-carboxyethyl)-8,8,18,18-tetrakis(3-((1,5-dicarboxy-3-(2-carboxyethyl)pentan-3-yl)amino)-3-oxopropyl)-5,10,16,21-tetraoxo-4,9,17,22-tetraazapentacosan-13-yl)amino)-6-oxohexyl)-1'-ethyl-[4,4'-bipyridine]-1,1'-diium bromide

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