Patent ID: 8729228

Claim:
A method of producing a modified (poly)peptide, comprising: modifying in an organic solvent a crown ether-bound (poly)peptide at one or more carboxylic groups by esterification or thioesterification and/or at the amino group of the N-terminal amino acid by amidation or alkylation, wherein the modifying by an ester or thioester bond is selected from the group consisting of the formation of (an) ester or thioester bond(s) with one or more (a) biocompatible polymers; (b) lipids; (c) linker molecules comprising a hydroxyl group or sulfhydryl group; (d) side-chain hydroxyl groups of said (poly)peptide; (e) oligonucleotides; (f) (pro)drugs; (g) markers; (h) labels; (i) small molecules having a cognate transport carrier; and any combination of (a) to (i).