Synthetic method of semeglutide

Abstract

The invention relates to a synthetic method of semeglutide. The preparation method comprises the following steps: 1) coupling glycine of Fmoc protected alpha amino on solid-phase synthetic resin, removing an Fmoc protecting group, then coupling according to a method of coupling amino acid or peptide fragment of Fmoc or Boc protected alpha amino, and then removing the Fmoc protecting group in sequence; 2) removing an X protecting group in the Lys (X); 3) coupling FmocAEEAOH, and then sequentially coupling FmocAEEAOH, FmocGluOtBu and octadecanedioic acid mono(1,1-dimethylethyl) ester by a methodof removing an Fmoc protecting group and then coupling; 4) cracking the resin and the side chain protecting group to obtain crude peptide; and 5) purifying to obtain the semeglutide refined peptide.The method provided by the invention has the advantages of simple process, low cost and high yield.

Description

technical field [0001] The invention relates to the field of polypeptide synthesis, in particular to the synthesis and purification method of semaglutide. [0002] technical background [0003] Semeglutide is a long-acting GLP-1 analogue developed by Novo Nordisk. The drug was first approved for marketing as an injection, which only needs to be administered by subcutaneous injection once a week. In 2019, the FDA approved the marketing of oral semaglutide. As the first oral GLP-1 analog diabetes drug, the market prospect of the drug is widely optimistic. [0004] From a structural point of view, semaglutide needs to connect the 20th Lys to two fatty chains of AEEA, γ-glutamic acid and octadecanedioic acid, and the 2nd position uses the unnatural amino acid aminoisobutyric acid. Compared with liraglutide, semaglutide has a longer fatty chain and increased hydrophobicity, but semaglutide is modified with short-chain PEG to greatly enhance hydrophilicity. After PEG modification...

AI Technical Summary

Problems solved by technology

The use of these methods for the synthesis of semaglutide basically does not consider the peptide sequence structure and characteristics of semaglutide itself in practical applications, such as the influence of the secondary structure of the peptide on the solid-phase synthesis of the peptide, the protection of the amino acid side chain The influence of groups on solid-phase coupling of polypeptides, the influence of longer side chain aliphatic chain hydrophobicity on solid-phase synthesis of polypeptides, the influence of coupling side reactions on product yield, the solubility and difficulty of condensation of fragment condensation, etc.

As a long peptide with a main chain of more than 30 amino acids and a longer side chain modification, the peptide sequence structure of semaglutide itself is analyzed. The first amino acid at the N-terminal His is very easy to racemize; the second amino acid at the N-terminal Coupling of amino acid Aib is very difficult due to the presence of a double substitution at the α-position; N-terminal fragment of semaglutide: H-His 1 -Aib 2 -Glu 3 -Gly 4 -Thr 5 -Phe 6 -Thr 7 -Ser 8 -Asp 9 -Val 10 -Ser 11 -Ser 12 -Tyr 13 -Leu 14 -, because of its strong hydrophobicity, it is easy to form secondary structures such as β-sheets, and the coupling is very difficult, especially Val 10 -Ser 11 Because of the hydrophobicity and double-beta substitution structure of the fragment, if the solid-phase carrier resin is loaded on the first residue at the C-terminus of the sequence, the subsequent fragments will receive very little rigid constraint from the solid-phase carrier resin. In solid-phase peptide synthesis It will seriously affect the coupling efficiency of subsequent residues; the side chain octadecanedioic acid is very difficult to couple because of its own hydrophobicity; the rigid structure of the aliphatic chain itself with a long side chain will seriously affect itself and adjacent residues condensation efficiency

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