L-threo-Pentonamide, N-(1-((((3-amino-5,6-dimethylpyrazinyl)methyl)amino)carbonyl)-2-methylbutyl)-5-cyclohexyl-2,4,5-trideoxy-4-((N-(N-(1-oxo-6-(((phenylmethoxy)carbonyl)amino)hexyl)-L-phenylalanyl)glycyl)amino)-, (S-(R*,R*))-