TY - JOUR
T1 - On-resin N-formylation of peptides: a head-to-head comparison of reagents in solid-phase synthesis of ligands for formyl peptide receptors
AU - Christensen, Simon Bendt
AU - Hansen, Anna Mette
AU - Franzyk, Henrik
PY - 2017/5/1
Y1 - 2017/5/1
N2 - General conditions for efficient on-resin N-formylation of peptides were identified by screening of a number of reagents comprising aliphatic formates (ethyl formate, 2,2,2-trifluoroethyl formate, and cyanomethyl formate), aromatic esters (phenyl formate and p-nitrophenyl formate), and N-formylimidazole and in situ activation of formic acid with the coupling reagent 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. Initially, reaction time and influence of solvent were examined for the formylation of a short model peptide. The most efficient reagents were examined further by using different linkers and solid supports in the synthesis of an array of longer formyl peptide ligands. For p-nitrophenyl formate and N-formylimidazole, almost complete conversion was reached within 2 h, albeit longer peptides attached to Tentagel resins via different linkers required an extended reaction time. Overall, the commercially available activated ester p-nitrophenyl formate proved to be most convenient and versatile as high formylation degrees were obtained after 1–3 h at room temperature, while either conventional or microwave-assisted heating allowed reduction of the formylation time to 20 min.
AB - General conditions for efficient on-resin N-formylation of peptides were identified by screening of a number of reagents comprising aliphatic formates (ethyl formate, 2,2,2-trifluoroethyl formate, and cyanomethyl formate), aromatic esters (phenyl formate and p-nitrophenyl formate), and N-formylimidazole and in situ activation of formic acid with the coupling reagent 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. Initially, reaction time and influence of solvent were examined for the formylation of a short model peptide. The most efficient reagents were examined further by using different linkers and solid supports in the synthesis of an array of longer formyl peptide ligands. For p-nitrophenyl formate and N-formylimidazole, almost complete conversion was reached within 2 h, albeit longer peptides attached to Tentagel resins via different linkers required an extended reaction time. Overall, the commercially available activated ester p-nitrophenyl formate proved to be most convenient and versatile as high formylation degrees were obtained after 1–3 h at room temperature, while either conventional or microwave-assisted heating allowed reduction of the formylation time to 20 min.
U2 - 10.1002/psc.2998
DO - 10.1002/psc.2998
M3 - Journal article
C2 - 28421689
SN - 1075-2617
VL - 23
SP - 410
EP - 415
JO - Journal of Peptide Science
JF - Journal of Peptide Science
IS - 5
ER -