Fmoc-D-His(Fmoc)-OH is widely used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). It serves as a protected form of histidine, where the Fmoc (fluorenylmethyloxycarbonyl) groups protect the amino and imidazole functionalities during the synthesis process. This protection ensures selective deprotection and coupling steps, which are crucial for building complex peptides with high precision. The compound is especially valuable in synthesizing peptides containing histidine residues, which are often involved in metal binding, enzyme catalysis, and protein-protein interactions. Its application is essential in producing peptides for research, pharmaceuticals, and biotechnology, where accurate sequence assembly is critical.