Fmoc-alpha-Glutamine is widely used in solid-phase peptide synthesis (SPPS) as a protected building block for incorporating glutamine residues into peptide chains. The Fmoc (9-fluorenylmethoxycarbonyl) group provides temporary protection for the alpha-amino group, allowing selective deprotection under mild basic conditions, typically with piperidine, while the side-chain amide of glutamine remains unaffected. This orthogonality with other protecting groups makes it ideal for stepwise assembly of complex peptides. Its stability and ease of handling make it a preferred choice in automated peptide synthesizers. It is commonly used in the production of therapeutic peptides, research reagents, and in the development of peptide-based drugs and vaccines. Due to the importance of glutamine in biological activity and protein structure, Fmoc-alpha-Glutamine plays a key role in synthesizing peptides with native-like functionality and conformation.