An improved method for the solution cyclization of peptides under pseudo-high dilution conditions.

Depending on the ring size, the cyclization of peptides often is accompanied by dimerization or cyclodimerization. Hence, these macrocyclizations have to be performed under high dilution conditions. Efficient cyclization of peptides in solution with a minimum amount of solvent succeeds, when a dual syringe pump is used to simultaneously add the linear peptide precursor and a coupling reagent from two separate syringes.