Proposed is a novel method for preparing liraglutide by means of an ionic liquid and a eutectic solvent, which are environment-friendly solvents. More specifically, the method is characterized in that fractionated peptide 1 represented by the following formula (1) and fractionated peptide 2 represented by the following formula (2) are subjected to a coupling reaction in the presence of an ionic liquid or a eutectic solvent. In preparing GLP-1 analogues such as liraglutide, the present method increases reactivity when producing liraglutide, which is an unprocessed reactant, by using an ionic liquid and a eutectic solvent as environment-friendly solvents instead of using organic solvents. Accordingly, through a relatively short and simple purification process, the present method has advantages of reducing the formation of related substances, improving purity, improving yields, shortening reaction times, reducing production cost, and lowering the manufacturing cost.

A peptide is efficiently produced by reacting a carboxyl group of an amino acid or intermediate peptide in which an amino group is protected, with an alkali metal salt or alkaline earth metal salt of an amino acid in which an amino group is not protected, or of an intermediate peptide in which an N-terminal is not protected, is a two-layer solvent composed of water and a hydrophobic organic solvent.

In certain embodiments a device is provided for electrorotation flow. In certain embodiments the device comprises a microfluidic channel comprising a plurality of electrodes disposed to provide dielectrophoretic (DEP) forces that are perpendicular to hydrodynamic flows along the channel; and a fluid within the channel providing the hydrodynamic flow along the channel; wherein the device is configured to apply focusing voltages to the electrodes that provide an electric field minimum in the channel and that focus cells, particles, and/or molecules or molecular complexes within the channel; and where the device is configured to apply rotation-inducing voltages to the electrodes that induce rotation of the cells, particles, molecules and/or molecular complexes as they flow through the channel.

It was found that a peptide compound that has an N-substituted-α,α-disubstituted amino acid residue at the N-terminus and containing a dipeptide residue in which the N-substituted-α,α-disubstituted amino acid residue and an N-substituted amino acid residue are linked together, can be efficiently produced by linking an N-unsubstituted-α,α-disubstituted amino acid whose amino group is protected with an electron-withdrawing protecting group to an N-substituted amino acid or a peptide compound having an N-substituted amino acid residue at the N-terminus, and then allowing a substituent-introducing agent to act in the presence of a specific base to selectively introduce a substituent to the amino group at the N-terminus.

A preparation method of a novel natural bioactive peptide Tubulysin U includes: dissolving a compound 2 in trifluoroacetic acid, heating under reflux to prepare an intermediate, reacting with a compound 3 and N,N-diisopropylethylamine to obtain a product, reacting the product with 2, 6-dimethylpyridine and tert-butyldimethylsilyl trifluoromethanesulfonate, adding sodium hydroxide after the reaction to prepare an intermediate acid, reacting the intermediate acid with a compound 6, HATU and N,N-diisopropylethylamine to obtain a product, adding triphenylphosphine to prepare an intermediate amine, adding a compound 8 and HATU to react, adding ammonium fluoride to prepare a first intermediate, adding sodium hydroxide to the first intermediate to prepare a second intermediate, adding acetic anhydride to the second intermediate to prepare a third intermediate, adding trifluoroacetic acid to the third intermediate to prepare a fourth intermediate, and adding formaldehyde and sodium cyanoborohydride to the fourth intermediate to react, thereby obtaining a target product.

It was found that a salt formed of an acid and a base having characteristics set forth below can inactivate a deprotecting agent, thereby suppressing redundant peptide elongation: (i) the base is different in type from a base used as a deprotecting agent, and (ii) a conjugate acid of the base has a pKa smaller than that of a conjugate acid of a base used as a deprotecting agent.

A preparation method of a novel natural bioactive peptide Tubulysin U includes: dissolving a compound 2 in trifluoroacetic acid, heating under reflux to prepare an intermediate, reacting with a compound 3 and N,N-diisopropylethylamine to obtain a product, reacting the product with 2, 6-dimethylpyridine and tert-butyldimethylsilyl trifluoromethanesulfonate, adding sodium hydroxide after the reaction to prepare an intermediate acid, reacting the intermediate acid with a compound 6, HATU and N,N-diisopropylethylamine to obtain a product, adding triphenylphosphine to prepare an intermediate amine, adding a compound 8 and HATU to react, adding ammonium fluoride to prepare a first intermediate, adding sodium hydroxide to the first intermediate to prepare a second intermediate, adding acetic anhydride to the second intermediate to prepare a third intermediate, adding trifluoroacetic acid to the third intermediate to prepare a fourth intermediate, and adding formaldehyde and sodium cyanoborohydride to the fourth intermediate to react, thereby obtaining a target product.

An object of the present invention is to provide a novel method having high efficiency and versatility for a peptide thioester and peptide. The present invention provides a method for producing a peptide thioester, comprising the steps of: (1) providing a peptide thioester having a CGC triplet at the C-terminal; (2) causing a transfer between an SH group of the C-terminal cysteine and a carbonyl group of the glycine in the CGC triplet to obtain an R-X-CG-thioester; and (3) causing, in the R-X-CG-thioester, a transfer between the SH group of the cysteine and a carbonyl group of X, and a transfer between an amino group of the cysteine and a thiol group of the glycine to obtain a peptide thioester, and a method for producing a peptide using the peptide thioester produced by this method.

The disclosure relates to the synthesis of amide containing compounds inflow. In particular, the disclosure relates to the synthesis of polypeptides via native chemical ligation inflow. The disclosure also relates to selective desulfurization or deselenization of amide containing compounds comprising a thiol, disulfide, selenol or diselenide functional group respectively, particularly polypeptides.

The present invention provides methods of making α4β7 peptide monmer and dimer antagonists. Methods of the present invention include solid phase and solution phase methods, as well as synthesis via condensation of smaller peptide fragments. Methods of the present invention further include methods directed to the synthesis of peptides comprising one or more penicillamine residues.