FMOC-Arg (ME, PBF)-OH is a kind of protected form of arginine. Arginine is double-protected by butyloxycarbonyl (BOC) and 2, 2, 4, 6, 7-pentamethyldihydrobenzofuran-5-sulfonyl (PBF). It is a derivative for introducing mono-methyl-arginine during Fmoc SPPS. Coupling can be carried out using any standard activation method. PBF protecting group can be removed by TFA-mediated cleavage reaction. As a kind of protected amino acid, it is an important intermediate in various fields such as peptide synthesis, asymmetric synthesis, medicinal chemistry as well as polymer chemistry.