A general method for functionalising both the C- and N-terminals of Tyr3-octreotate

A new method has been developed for solid-phase peptide synthesis (SPPS) via the Fmoc strategy that allows functionalisation of both the C- and N-terminals of Tyr3-octreotate. N-α-Fluorenylmethyloxycarbonyl-l-threonine allyl ester, the starting amino acid, was loaded onto the 3,4-dihydro-2H-pyran-2-ylmethoxymethyl polystyrene (DHP) resin via its side chain alcohol group and the cyclic Tyr3-octreotate was synthesised. The C- and N-terminals were functionalised with DOTA (1,4,7,10-tetraazacyclodecane-N′,N′′,N′′′,N′′′′-tetraacetic acid) and HYNIC (6-hydrazinonicotinic acid).