Cost-Effective Flow Peptide Synthesis: Metamorphosis of HPLC
Viktor Farkas, Kristóf Ferentzi, Kata Horváti, András Perczel
Abstract
We present the further development and fine-tuning of an efficient, economic (≤3 equivalents of activated amino acid ), and environmentally friendly (6 mL organic waste/cycle) procedure for peptide synthesis using a fast amino acid coupling reaction (1.7 min). The designed setup can assist the synthesis of highly pure (>80%) raw materials even for long (up to 30 aa.) and/or difficult sequences. The significant reduction of the coupling time by using the effective PyAOP and N,N′-diisopropylcarbodiimide/HOBt coupling reagents was achieved, and virtually racemization-free (L-His/D-His <1–5%) peptides can now be synthesized, even at higher column temperature: T = 70 °C. The purity of the product and the efficiency of the synthesis were evaluated using different solid phase supports and protocols. We successfully completed the synthesis of “difficult” sequences [e.g., insulin B-chain and cecropin A(1–7)-melittin(2–9) hybrid peptide] wasting only a fraction of the organic solvents compared to other methods, furthering peptide chemistry toward a greener approach.