Fmoc-Gln-OH is widely used in peptide synthesis, particularly in solid-phase peptide synthesis (SPPS). It serves as a building block for introducing glutamine residues into peptide chains. The Fmoc (fluorenylmethyloxycarbonyl) group acts as a protective group for the amino group, ensuring selective reactions during the synthesis process. This compound is essential in the production of peptides for research, pharmaceuticals, and biotechnology applications, including the development of therapeutic peptides, vaccines, and diagnostic agents. Its stability and compatibility with SPPS protocols make it a valuable tool in organic and medicinal chemistry.