: 3-(3-{[(2-{[5-(2-tert-Butoxycarbonyl-ethyl)-2-hydroxy-benzyl]-tert-butoxycarbonylmethyl-amino}-ethyl)-tert-butoxycarbonylmethyl-amino]-methyl}-4-hydroxy-phenyl)-propionic acid, N,N'-Bis[2-hydroxy-5-(carboxyethyl)-benzyl]ethylenediamine-N,N'-diacetic acid, tris tert-butyl ester