Used primarily in peptide synthesis, Fmoc-N-Me-Arg(Mtr)-OH serves as a protected N-methyl arginine derivative. It is particularly valuable in solid-phase peptide synthesis (SPPS) due to its Fmoc (9-fluorenylmethoxycarbonyl) protecting group on the N-methylated alpha-amino group, which can be easily removed under basic conditions. The Mtr (4-methoxy-2,3,6-trimethylbenzenesulfonyl) group protects the guanidine function of arginine, preventing unwanted side reactions during peptide chain assembly. The N-methylation enables the incorporation of modified arginine residues that can influence peptide structure, stability, and bioactivity. This makes it essential for synthesizing peptides containing N-methyl arginine, especially in the production of bioactive peptides, pharmaceuticals, and research applications where precise peptide sequences are required. Its stability and compatibility with SPPS protocols ensure efficient and high-yield peptide production.