(S)-2-[((S)-2-tert-Butoxycarbonylamino-octanoyl)-methyl-amino]-propionic acid methyl ester

2-{[2-(2-{2-[(2-{2-[(2-tert-butoxycarbonylamino-4-methyl-pentanoyl)-methyl-amino]-3-phenyl-propionylamino}-octanoyl)-methyl-amino]-propionyloxy}-propionylamino)-octanoyl]-methyl-amino}-4-methyl-pentanoic acid tert-butyl ester