Used as a protected amino acid derivative in peptide synthesis, particularly in the preparation of complex peptides where steric hindrance and selective deprotection are critical. The Boc (tert-butoxycarbonyl) group provides temporary N-protection that is stable under basic conditions but can be removed under mild acidic conditions, allowing for stepwise assembly of peptide chains. The N-methylation on the allo-isoleucine residue enhances metabolic stability and influences peptide conformation, making it valuable in the design of bioactive peptides with improved pharmacokinetic properties. The DCHA (dicyclohexylamine) salt form improves crystallinity and handling during solid-phase or solution-phase synthesis. Commonly applied in pharmaceutical research, especially in the development of peptide-based drugs targeting metabolic and neurological disorders.