Fmoc-4-Amc-OH is an Fmoc-protected amino acid derivative widely used as a building block in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). The Fmoc (9-fluorenylmethyloxycarbonyl) group protects the amino functionality, which can be selectively removed under mild basic conditions (e.g., piperidine in DMF), enabling the controlled, stepwise assembly of peptide chains. The free carboxylic acid group allows for efficient coupling to the resin or growing peptide chain using standard activation methods. This compound is especially valuable for incorporating unnatural or modified amino acids into bioactive peptides, peptidomimetics, and peptide conjugates, which play key roles in drug discovery, development, and therapeutic applications. Additionally, it is utilized in the preparation of peptide-based biomaterials for biomedical research, including tissue engineering scaffolds and targeted drug delivery systems. Its high stability under acidic conditions, orthogonal deprotection strategy, and compatibility with automated synthesizers make it a preferred reagent in both academic laboratories and industrial-scale peptide production.