Used in peptide synthesis as an intermediate, particularly in the preparation of peptide prodrugs. It acts as a protecting group for amino acids, ensuring selective reactions during the synthesis process. The PAB (para-aminobenzyl) and PNP (para-nitrophenyl) groups facilitate the release of active drug molecules in targeted drug delivery systems. Commonly employed in the development of anticancer and antiviral agents, where controlled release and stability are critical. Its design allows for efficient cleavage under specific conditions, making it valuable in bioconjugation and prodrug strategies.