Abstract: A method for purifying a long chain polypeptide includes: 1) purification step: connecting two chromatographic columns in series to separate a crude product, in which the particle size of a packing in an upstream chromatographic column is larger than that in a downstream chromatographic column; optionally, the method further includes step 2): using the upstream chromatographic column in step 1) for a salt conversion, loading the target peak product obtained in step 1) and rinsing with 95-85% of the A2 and 5-15% of the B for 15-30 min for a desalination, wherein A2 phase is an acetic acid aqueous solution with a volume ratio of 0.05%-0.2%; B phase is an organic phase acetonitrile, and the detection wavelength is 230 nm.

Abstract: A method for purifying a long chain polypeptide includes: 1) purification step: connecting two chromatographic columns in series to separate a crude product, in which the particle size of a packing in an upstream chromatographic column is larger than that in a downstream chromatographic column; optionally, the method further includes step 2): using the upstream chromatographic column in step 1) for a salt conversion, loading the target peak product obtained in step 1) and rinsing with 95-85% of the A2 and 5-15% of the B for 15-30 min for a desalination, wherein A2 phase is an acetic acid aqueous solution with a volume ratio of 0.05%-0.2%; B phase is an organic phase acetonitrile, and the detection wavelength is 230 nm.

Abstract: A method for preparing Lixisenatide. According to a peptide sequence structure of Lixisenatide peptide, specially protected serine dipeptide is used as a raw material and coupled into a peptide sequence. Because of a ring-shaped structure similar to that of proline is formed, the rotation of a peptide bond can be effectively prevented, the contraction of a peptide chain curling agent is suppressed, so that active functional groups are fully exposed, thereby facilitating the coupling of the amino acid, and reducing the occurrence of defects and other side effects.

Abstract: Provided is a method for solid phase synthesis of Etelcalcetide, comprising synthesizing Etelcalcetide backbone peptide resin, removing the side chain protecting group of Cys in the peptide chain, and then activating the sulfydryl group of the Cys side chain on the peptide resin with 2,2?-dithiodipyridine and constructing a disulfide bond with L-Cys, such that a crude Etelcalcetide peptide is obtained by cleaving. The method does not require undergoing multi-step purification, the yield and purity of the obtained crude peptide are relatively high, and the total yield of the refined peptide after purification is greatly increased.

Abstract: Disclosed is a method of synthesizing linaclotide through completely selective formation of three disulfide bonds, comprising the steps of: 1) synthesizing linaclotide precursor resin through solid-phase synthesis; 2) forming the first disulfide bond through solid phase oxidation; 3) forming the second disulfide bond through liquid phase oxidation; and 4) deprotecting methyl in the methyl-protected cysteine, and oxidatively coupling the third disulfide bond to obtain linaclotide. The method has mild reaction conditions with low cost, high yield and high purity product, is a simple and stable process and is suitable for large-scale production.

Abstract: The present invention relates to a preparation method of a long-chain compound, which includes the following steps: (1) carrying out condensation reaction on H—R2 and R5N-Glu(OR4)—OR3, wherein, R3 is a carboxyl protecting group, R4 is a carboxyl activating group, and R5 is an amino protecting group; obtaining a compound of formula II; (2) removing carboxyl protecting group R3 and amino protecting group R5 of the compound shown in formula II to obtain a compound of formula III; (3) carrying out condensation reaction on the compound shown in formula III and to obtain a compound shown in formula I. The method reduces the time of deprotection, and all the reactions can be carried out in a solvent with low boiling point. The post-processing requires only simple washing and recrystallization to obtain the product with higher purity, so the method is suitable for large-scale production.

Abstract: The present invention relates to a high performance liquid chromatography method for polypeptide mixtures. Specifically, the method including the following steps: step (1): preparing a solution of the glatiramer acetate to be tested; step (2): performing gradient elution on a sample to be tested with an anion exchange liquid chromatography, a cation exchange liquid chromatography, or a reversed-phase liquid chromatography; step (3): determining a peak area corresponding to each component of the glatiramer acetate, comparing the peak area with to a peak area of a reference substance to determine whether the content of each component of the sample to be tested is in a qualified range.

Abstract: The present invention relates to the field of polypeptides, and particularly, provides a pharmaceutical composition and a manufacturing method thereof. The pharmaceutical composition comprises a Liraglutide, and the manufacturing method of the pharmaceutical composition comprises: mixing, in a solvent, the Liraglutide and an adjuvant, stirring the resultant mixture at 500-1100 rpm until homogeneous, and adjusting the pH value to 7.5-9.5. Various manufacturing process parameters can influence the stability of Liraglutide and may cause significant changes in oligomerization, single maximal impurity, and total impurity. The infrared spectra show an amide band I (at about 1645 nm?1), indicating the presence of an ?-helix structure, with strong absorption and a basically consistent peak shape. The present invention controls, by examination of the secondary structure of a polypeptide, parameter screening of a pharmaceutical preparation process.

Abstract: A method for preparing Sermaglutide. Amino acid protected by Fmoc-Lys(Alloc)-OH is used as a raw material, and protection is carried out by selecting Pd(PPh3)4. In one aspect, the operation process is simple, one or two times of elimination reactions are required only, each time lasts 10 min to 30 min, and no side reaction occurs, and the operation process is safe, so that the preparation method is suitable for expanding production. The risk of His racemization can be reduced to the greatest extent in the process by using Boc-His(Boc)-OH.DCHA and Boc-His(Trt)-OH as raw materials. The synthesis efficiency is improved by performing coupling by using special segments.

Abstract: Provided is a method for solid phase synthesis of Etelcalcetide, comprising synthesizing Etelcalcetide backbone peptide resin, removing the side chain protecting group of Cys in the peptide chain, and then activating the sulfydryl group of the Cys side chain on the peptide resin with 2,2?-dithiodipyridine and constructing a disulfide bond with L-Cys, such that a crude Etelcalcetide peptide is obtained by cleaving. The method does not require undergoing multi-step purification, the yield and purity of the obtained crude peptide are relatively high, and the total yield of the refined peptide after purification is greatly increased.

Abstract: Disclosed is a method of synthesizing linaclotide through completely selective formation of three disulfide bonds, comprising the steps of: 1) synthesizing linaclotide precursor resin through solid-phase synthesis; 2) forming the first disulfide bond through solid phase oxidation; 3) forming the second disulfide bond through liquid phase oxidation; and 4) deprotecting methyl in the methyl-protected cysteine, and oxidatively coupling the third disulfide bond to obtain linaclotide. The method has mild reaction conditions with low cost, high yield and high purity product, is a simple and stable process and is suitable for large-scale production.

Abstract: The present invention relates to a preparation method of a long-chain compound, which includes the following steps: (1) carrying out condensation reaction on H—R2 and R5N-Glu(OR4)—OR3, wherein, R3 is a carboxyl protecting group, R4 is a carboxyl activating group, and R5 is an amino protecting group; obtaining a compound of formula II; (2) removing carboxyl protecting group R3 and amino protecting group R5 of the compound shown in formula II to obtain a compound of formula III; (3) carrying out condensation reaction on the compound shown in formula III and to obtain a compound shown in formula I. The method reduces the time of deprotection, and all the reactions can be carried out in a solvent with low boiling point. The post-processing requires only simple washing and recrystallization to obtain the product with higher purity, so the method is suitable for large-scale production.

Abstract: The present invention relates to a high performance liquid chromatography method for polypeptide mixtures. Specifically, the method including the following steps: step (1): preparing a solution of the glatiramer acetate to be tested; step (2): performing gradient elution on a sample to be tested with an anion exchange liquid chromatography, a cation exchange liquid chromatography, or a reversed-phase liquid chromatography; step (3): determining a peak area corresponding to each component of the glatiramer acetate, comparing the peak area with to a peak area of a reference substance to determine whether the content of each component of the sample to be tested is in a qualified range.