This chemical is the Fmoc-protected derivative of L-ornithine, (S)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)amino)-5-aminopentanoic acid, where the α-amino group is protected by the fluorenylmethoxycarbonyl (Fmoc) group, while the side-chain δ-amino group at position 5 remains unprotected. It is primarily used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). The Fmoc group acts as a temporary protecting group for the α-amino functionality, which can be easily removed using a base such as piperidine under mild conditions. This allows for the sequential addition of amino acids to build peptides with high precision, though the free side-chain amino group may require specific handling or further protection to prevent unwanted side reactions. The compound is especially valuable in the production of complex peptides and proteins for pharmaceutical research, drug development, and biochemical studies. Its stability makes it suitable for use in automated peptide synthesizers. Additionally, it is utilized in the synthesis of peptide-based drugs, diagnostic agents, and biomaterials.