FMOC-HIS(MTT)-OH is primarily used in peptide synthesis as a protected form of histidine. The FMOC group protects the amino group, while the MTT group protects the imidazole side chain of histidine, preventing unwanted reactions during the peptide assembly process. This compound is particularly valuable in solid-phase peptide synthesis (SPPS), where selective deprotection of the FMOC group allows for the stepwise addition of amino acids to build the desired peptide sequence. The MTT group is stable under standard FMOC deprotection conditions but can be selectively removed when needed, ensuring the integrity of the histidine side chain throughout the synthesis. This makes FMOC-HIS(MTT)-OH a crucial reagent in the production of peptides for research, pharmaceuticals, and biotechnology applications.