Used in peptide synthesis to incorporate nitro-protected arginine residues, enabling controlled deprotection and further modification in the development of bioactive peptides. The Fmoc group allows for solid-phase synthesis under mild basic conditions, while the nitro group protects the guanidine functionality of arginine, preventing side reactions. After peptide assembly, the nitro group can be selectively reduced to yield free L-arginine, useful in studies of enzyme substrates, inhibitors, and signaling molecules. Commonly applied in research related to nitric oxide synthase and cardiovascular or neurological pathways.