(S)-2-[(S)-4-{(R)-2-[(S)-2-Acetylamino-3-(4-hydroxy-phenyl)-propionylamino]-3-phenyl-propionyl}-3-(3-amino-propyl)-2-oxo-piperazin-1-yl]-N-methyl-3-naphthalen-2-yl-propionamide

{3-[(S)-1-((R)-2-Amino-3-phenyl-propionyl)-4-((S)-1-methylcarbamoyl-2-naphthalen-2-yl-ethyl)-3-oxo-piperazin-2-yl]-propyl}-carbamic acid benzyl ester

{3-[(S)-1-{(R)-2-[(S)-2-Acetylamino-3-(4-hydroxy-phenyl)-propionylamino]-3-phenyl-propionyl}-4-((S)-1-methylcarbamoyl-2-naphthalen-2-yl-ethyl)-3-oxo-piperazin-2-yl]-propyl}-carbamic acid benzyl ester