Fmoc-(S)-3-amino-3-(3-nitrophenyl)propanoic acid is primarily used in peptide synthesis as a building block. Its Fmoc (fluorenylmethyloxycarbonyl) protecting group allows for the controlled assembly of peptides, ensuring precise sequence formation. The nitro group on the phenyl ring can serve as a handle for further chemical modifications or as a tag for detection and purification processes. This compound is particularly valuable in the development of peptide-based drugs, where specific amino acid sequences are critical for biological activity. Additionally, it finds applications in research for studying protein interactions and designing peptide mimetics.