Z-NLE-OSU is widely used in peptide synthesis as an active ester derivative. It serves as a key reagent for coupling amino acids during the formation of peptide bonds, particularly in solid-phase peptide synthesis (SPPS). Its application is crucial in the preparation of complex peptides and proteins, enabling efficient and selective reactions. Additionally, it is employed in biochemical research for labeling and modifying peptides, aiding in the study of protein interactions and functions. Its stability and reactivity make it a valuable tool in the development of therapeutic peptides and bioconjugates.