SYNTHESIS OF TRITIUM LABELED TRH-LIKE PEPTIDES USING ASYMMETRIC ANHYDRIDE COUPLING

A method is presented for the preparation of [H-3]-labelled TRH-like tripeptides. The synthesis involves preparation of the appropriate dipeptide by the solid phase procedure using Fmoc-protection and the [H-3]-labelled pyroglutamic acid is then coupled as a mixed anhydride with Fmoc-phenylalanine. Conditions suitable for the conversion of [H-3]-glutamine to [H-3]-pyroglutamic acid are also described. The [H-3]-labelled tripeptides are obtained in a high state of purity and with efficient incorporation of radiolabel.