Poster Presentation International Peptide Symposium 2023

Solid-phase synthesis (SPS) plays key role in the preparation of peptides. With regard to further use of product, efficiency of anchoring and removing of material from polymeric carrier depends significantly on the appropriate choice of a linker¹. Herein, a series of N-terminally Fmoc-protected linkers of the general formula Fmoc−X−CO−O−Y−COOH (I) have been prepared, where X is −NH−CH₂−CH₂− or 4−(aminomethyl)phenyl and Y is –(CH₂)_n−, (n = 1 or 4) or 4-methylphenyl². These linkers were easily attached via their C-terminal carboxyl group to the resin bearing a free amino moiety. After cleavage of the terminal Fmoc-group, the linkers were extended by a model hexapeptide (Tyr-Ala-Lys-Gly-Glu-Ala) using a standard Fmoc-SPSS technique (II). Our new ester linkers are acid-stable and resistant to the base-mediated diketopiperazine formation, which occurs during the synthesis of peptides containing ester bonds; they are stable at neutral pH in aqueous buffers for days but can be effectively cleaved with 0.1 M NaOH within minutes or hours (III). These properties predetermine directly our linkers as useful tools of immobilization peptides on resins, their biological testing in aqueous buffers at neutral pH and their non-destructive cleavage if needed.