Facile synthesis of C-terminal peptide hydrazide and thioester of NY-ESO-1 (A39-A68) from an Fmoc-hydrazine 2-chlorotrityl chloride resin

The NY-ESO-1 (A39-A68) peptide hydrazide was prepared through 9-fluorenyl-methoxycarbonyl solid-phase peptide synthesis (Fmoc SPPS) from a new 9-fluorenyl-methoxycarbonyl hydrazine 2-chlorotrityl chloride (Fmoc-hydrazine 2CTC) resin. The new resin was ideal for long-term storage and usage in Fmoc SPPS. Besides, the title peptide hydrazide could be transformed nearly quantitatively into the corresponding peptide thioester, which was both isolable and usable directly in native chemical ligation (NCL).