3-Phenyl-2-[2-(2-phenylacetylamino-benzoylamino)-benzoylamino]-propionic acid ethyl ester

2-{2-[2-(3-Methyl-benzoylamino)-benzoylamino]-benzoylamino}-3-phenyl-propionic acid ethyl ester

2-(2-{2-[2-(4-Chloro-phenyl)-acetylamino]-benzoylamino}-benzoylamino)-3-phenyl-propionic acid ethyl ester

2-{2-[2-(2-1H-Indol-3-yl-acetylamino)-benzoylamino]-benzoylamino}-3-phenyl-propionic acid ethyl ester