Cbz-Asp(OtBu)-Phe-Glu(OtBu)-Glu(OtBu)-Ile-Pro-OH is a protected hexapeptide used in peptide synthesis. It consists of aspartic acid (Asp), phenylalanine (Phe), glutamic acid (Glu), isoleucine (Ile), and proline (Pro). The Cbz (Carbobenzyloxy) group protects the N-terminus of aspartic acid, while the OtBu (tert-butyl) groups protect the hydroxyl groups of the glutamic acid residues. The remaining amino acids are in their free forms, with the C-terminus of the proline residue indicated by -OH, allowing for further coupling or modifications. This hexapeptide is designed for controlled reactivity and stability during peptide synthesis.