Polypeptide with modified structure and application thereof

Abstract

The invention provides a series of polypeptides containing modified structures, the series of polypeptides act on three targets of GLP-1, GIP and GCG and have the prospect of being developed into drugs for preventing or treating metabolic diseases, and the sequence of the polypeptides is shown as a formula Z-3. # imgabs0 #

Description

Polypeptides with modified structures and their applications Technical Field

[0001] The present invention relates to a series of polypeptides with modified structures and applications thereof. Specifically, the present invention relates to a series of polypeptides with stapled structures, a pharmaceutical composition containing the series of polypeptides and applications thereof in treating metabolic diseases. Background Art

[0002] Glucagon-like peptide-1 (GLP-1) and insulinotropic peptide (GIP) are incretins, and glucagon (GCG) is secreted by pancreatic α-cells. The aforementioned substances can directly or indirectly affect the body's glucose metabolism and / or lipid metabolism. Therefore, compounds that act on GLP-1, GIP, and GCG have the prospect of being developed into drugs for the treatment of metabolic diseases. For example, the compounds (peptides) that act on GLP-1, exenatide, liraglutide, and semaglutide, which are already on the market, are drugs for the treatment of type 2 diabetes mellitus type 2 (T2DM) and / or obesity.

[0003] However, compounds that target a single GLP-1, GIP, or GCG often have deficiencies in their therapeutic areas, therapeutic effects, and metabolic behavior, which in turn impact their drugability or post-market clinical applications. Therefore, efforts are underway to develop compounds that target multiple targets, hoping to simultaneously intervene through multiple mechanisms of action and achieve better clinical outcomes. Tirzepatide, a dual GLP-1 / GIP agonist developed by Eli Lilly, has demonstrated superior efficacy to semaglutide in head-to-head clinical trials and has been approved for marketing. Another example is LY3437943, a triple GLP-1 / GIP / GCG agonist developed by Eli Lilly, which has also demonstrated promising clinical efficacy in clinical studies and holds great promise for development.

[0004] GLP-1R / GIPR / GCGR multiple agonists can activate the molecular mechanisms of blood glucose regulatory receptors, affecting food intake and satiety through different mechanisms, and play a role in maintaining weight homeostasis. Research has also found that because GLP-1 receptor agonists can stimulate the GLP-1 receptor to promote incretin production, resulting in excellent blood glucose lowering and weight loss effects, they can also treat NASH (non-alcoholic steatohepatitis) through multi-pathway synergistic effects, suggesting that compounds acting on this target or multiple targets have the potential to be developed into drugs for the prevention and / or treatment of a range of specific diseases related to abnormal glucose metabolism and / or lipid metabolism.

[0005] Summary of the Invention

[0006] The present invention aims to address the deficiencies of the prior art and provides a series of polypeptides with modified structures and pharmaceutically acceptable salts thereof. In in vitro experiments, this series of polypeptides exhibits good effects on the GLP-1 receptor (GLP-1R), GIP receptor (GIPR) and GCG receptor (GCGR), and has good drug development prospects.

[0007] The present invention provides a polypeptide with a modified structure having a polypeptide sequence represented by Formula Z or a pharmaceutically acceptable salt thereof:

[0008] X5X0X6GT X a TSDY SX b X1X7X8 KX9X 10 X 11 X0 X4FX 12 X 13 X 14 X c X d X 15 GG PSSGA PPPS0

[0009] Formula Z

[0010] in:

[0011] X0 is independently selected from Or Aib or alanine (Ala, A), the structure of Aib is

[0012] X1 is independently selected from α-methyl substituted leucine (α-MeLeu, α-MeL), tyrosine (Tyr, Y) or Aib, wherein the α-MeL has the structure

[0013] X4 is selected from α-methyl substituted lysine (α-MeLys, α-MeK), D-lysine (dK), L-ornithine (L-Ornithine, L-Orn), alanine (Ala, A), lysine (Lys, K), glutamic acid (Glu, E) or leucine (Leu, L); the structure of the α-methyl substituted lysine is The structure of D-lysine (dK) is The structure of L-Ornithine (L-Ornithine, L-Orn) is

[0014] X5 is selected from tyrosine (Tyr, Y) or histidine (His, H);

[0015] X6 is selected from glutamine (Gln, Q) or histidine (His, H);

[0016] X7 is selected from leucine (Leu, L) or lysine (Lys, K);

[0017] X8 is selected from aspartic acid (Asp, D) or glutamic acid (Glu, E);

[0018] X9 is selected from lysine (Lys, K), glutamine (Gln, Q) or glutamic acid (Glu, E);

[0019] X 10 is selected from alanine (Ala, A) or tyrosine (Tyr, Y);

[0020] X 11 is selected from lysine (Lys, K), glutamine (Gln, Q) or alanine (Ala, A);

[0021] X 12 is selected from valine (Val, V) or isoleucine (Ile, I);

[0022] X 13 is selected from lysine (Lys, K), glutamine (Gln, Q) or glutamic acid (Glu, E);

[0023] X 14 is selected from lysine (Lys, K), tryptophan (Trp, W), tyrosine (Tyr, Y), glutamic acid (Glu, E) or phenylalanine (Phe, F);

[0024] X 15 Selected from lysine (Lys, K) or glutamic acid (Glu, E);

[0025] X a is selected from phenylalanine (Phe, F) or α-methyl substituted phenylalanine (α-MePhe, α-MeF), wherein the structure of α-methyl substituted phenylalanine is

[0026] X b is selected from lysine (Lys, K) or isoleucine (Ile, I);

[0027] X c is selected from leucine (Leu, L) or phenylalanine (Phe, F);

[0028] X d is selected from leucine (Leu, L) or isoleucine (Ile, I);

[0029] S0 is selected from (i.e., the C-terminal amino acid is optionally amidated to form a C-terminal primary amide);

[0030] And the compound (polypeptide) has the following modifications:

[0031] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure (stapled body) similar to a "staple" structure (peptide stapled), wherein i is independently selected from 12, 14, 16, 17, 19, 21, 24 or 25, and j is independently selected from 2, 3, 4, 5 or 7,

[0032] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures Condensation connected;

[0033] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid;

[0034] X3 is selected from

[0035] R1 and R2 are independently selected from

[0036] m is selected from 1, 2 or 3;

[0037] p is selected from 1 or 2;

[0038] n is selected from 8, 9 or 10.

[0039] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof has a polypeptide sequence as shown in Formula Z-1:

[0040] X5X0X6GT FTSDY SX b X1X7X8 KX9X 10 X 11 X0 X4FX 12 X 13 X 14 X c X d X 15 GG PSSGA PPPS0

[0041] Formula Z-1

[0042] The compound (polypeptide) has the following modifications:

[0043] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure (stapled body) similar to a "staple" (peptide stapled) structure, wherein i is independently selected from 12, 14, 16, 17, 19, 21, 24 or 25, and j is independently selected from 2, 3, 4, 5 or 7,

[0044] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures The other variables are as defined in the present invention.

[0045] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof has a polypeptide sequence as shown in Formula Z-2:

[0046] X5X0X6GT FTSDY SIX1X7X8 KX9X 10 X 11 X0 X4FX 12 X 13 X 14 LLX 15 GG PSSGA PPPS0

[0047] Formula Z-2

[0048] The compound (polypeptide) has the following modifications:

[0049] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure (stapled body) similar to a "staple" structure, wherein i is independently selected from 12, 14, 16, 17, 19, 21, 24, 25, and j is independently selected from 2, 3, 4, 5, 7,

[0050] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures The other variables are as defined in the present invention.

[0051] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof has a polypeptide sequence as shown in Formula Z-3:

[0052] X5X0X6GT FTSDY SIX1X7X8 KX9X 10 X 11 X0 X4FX 12 X 13 X 14 LLX 15 GG PSSGA PPPS0

[0053] Formula Z-3

[0054] And the polypeptide compound has the following modifications:

[0055] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure (stapled body) similar to a "staple" structure, wherein i is independently selected from 14, 17, 19, 21, 24 or 25, and j is independently selected from 3, 4, 5 or 7,

[0056] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures Condensation connected;

[0057] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid;

[0058] X3 is selected from:

[0059] R1 and R2 are independently selected from

[0060] m is selected from 1, 2 or 3;

[0061] p is selected from 1 or 2;

[0062] n is selected from 8, 9 or 10; other variables are as defined in the present invention.

[0063] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof has a polypeptide sequence as shown in Formula Z-4:

[0064] YX0QGT FTSDY SX b X1LD KKAQX0 X4FX 12 X 13 X 14 X c X d X 15 GG PSSGA PPPS0

[0065] Formula Z-4

[0066] S0 is selected from (i.e., the C-terminal amino acid is optionally amidated to form a C-terminal primary amide);

[0067] And the polypeptide compound has the following modifications:

[0068] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure (stapled body) similar to a "staple" structure, wherein i is independently selected from 12, 17, 21 or 25; j is independently selected from 3, 4 or 7,

[0069] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures Condensation connected;

[0070] X2 is selected from and; wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid;

[0071] X3 is selected from:

[0072] m is selected from 1, 2 or 3;

[0073] p is selected from 1 or 2;

[0074] n is selected from 8, 9 or 10; other variables are as defined in the present invention.

[0075] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof has a polypeptide sequence as shown in Formula Z-5:

[0076] YX0QGT X a TSDY SIX1KD KKAQX0 X4FIX 13 Y LLX 15 GG PSSGA PPPS0

[0077] Type Z-5

[0078] And the polypeptide compound has the following modifications:

[0079] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure similar to a "staple" structure, wherein i is independently selected from 14; j is independently selected from 3,

[0080] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures Condensation connected;

[0081] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid;

[0082] X3 is selected from:

[0083] m is selected from 1, 2 or 3;

[0084] p is selected from 1 or 2;

[0085] n is selected from 8, 9 or 10; other variables are as defined in the present invention.

[0086] In some embodiments of the present invention, the polypeptides with modified structures or pharmaceutically acceptable salts thereof have polypeptide sequences as shown in Formulas Z-6, Z-7, Z-8, Z-9, Z-10, Z-11, Z-12, and Z-13, respectively:

[0087] X5X0X6GT FTSDY SIX1LX8 KKX 10 X 11 X0 X4FX 12 X 13 X 14 LLX 15 GG PSSGA PPPS0

[0088] Formula Z-6

[0089] YX0QGT FTSDY SIX1LD KKAX 11 X0 X4FIX 13 X 14 LLX 15 GG PSSGA PPPS0

[0090] Formula Z-7

[0091] YX0QGT FTSDY SIX1X7D KKAQX0 X4FIX 13 Y LLX 15 GG PSSGA PPPS0

[0092] Formula Z-8

[0093] YX0QGT FTSDY SXbX1LD KKAQX0 X4FX 12 EX 14 X c XdX 15 GG PSSGA PPPS0

[0094] Formula Z-9

[0095] YX0QGT FTSDY SX b X1LD KKAQX0 KFX 12 EX 14 LX d X 15 GG PSSGA PPPS0

[0096] Formula Z-10

[0097] [[ID=�4]]YX0QGT FTSDY SX b X1KD KKAQX0 X4FIEY LLX 15 GG PSSGA PPPS0

[0098] Formula Z-11

[0099] YX0QGT FTSDY SIX1KD KKAQX0 X4FIEY LLEGG PSSGA PPPS0

[0100] Type Z-12

[0101] YX0QGT X a TSDY SIX1KD KKAQX0 X4FIEY LLX 15 GG PSSGA PPPS0

[0102] Type Z-13

[0103] The compound (polypeptide) has the following modifications:

[0104] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure (stapled body) similar to a "staple" structure, wherein i is independently selected from 12, 14, 16, 17, 19, 21, 24 or 25, and j is independently selected from 2, 3, 4, 5 or 7,

[0105] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures Condensation connected;

[0106] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid;

[0107] X3 is selected from:

[0108] R1 and R2 are independently selected from

[0109] m is selected from 1, 2 or 3;

[0110] p is selected from 1 or 2;

[0111] n is selected from 8, 9 or 10; other variables are as defined in the present invention.

[0112] In some embodiments of the present invention, S0 in the above polypeptide sequence is That is, the C-terminal amino acid is amidated to a primary amide, and the other variables are as defined in the present invention.

[0113] In some embodiments of the present invention, the second amino acid X0 in the polypeptide sequence is Aib, and other variables are as defined in the present invention.

[0114] In some embodiments of the present invention, the amino acid X0 at position 20 in the polypeptide sequence is Aib, and other variables are as defined in the present invention.

[0115] In some embodiments of the present invention, amino acids X0 at positions 2 and 20 in the polypeptide sequence are both Aib, and other variables are as defined in the present invention.

[0116] In some embodiments of the present invention, i is 12, j is 4, i+j is 16, and other variables are as defined in the present invention.

[0117] In some embodiments of the present invention, i is 14, j is 3, i+j is 17, and other variables are as defined in the present invention.

[0118] In some embodiments of the present invention, i is 16, j is 3, i+j is 19, and other variables are as defined in the present invention.

[0119] In some embodiments of the present invention, i is 17, j is 4, i+j is 21, and other variables are as defined in the present invention.

[0120] In some embodiments of the present invention, i is 17, j is 7, i+j is 24, and other variables are as defined in the present invention.

[0121] In some embodiments of the present invention, i is 19, j is 5, i+j is 24, and other variables are as defined in the present invention.

[0122] In some embodiments of the present invention, i is 21, j is 7, i+j is 28, and other variables are as defined in the present invention.

[0123] In some embodiments of the present invention, i is 24, j is 4, i+j is 28, and other variables are as defined in the present invention.

[0124] In some embodiments of the present invention, i is 25, j is 3, i+j is 28, and other variables are as defined in the present invention.

[0125] In some embodiments of the present invention, the first amino acid X5 in the polypeptide sequence is Y, and other variables are as defined in the present invention.

[0126] In some embodiments of the present invention, the first amino acid X5 in the polypeptide sequence is H, and other variables are as defined in the present invention.

[0127] In some embodiments of the present invention, the third amino acid X6 in the polypeptide sequence is Q, and other variables are as defined in the present invention.

[0128] In some embodiments of the present invention, the third amino acid X6 in the polypeptide sequence is H, and other variables are as defined in the present invention.

[0129] In some embodiments of the present invention, the sixth amino acid X in the polypeptide sequence a is F, and other variables are as defined in the present invention.

[0130] In some embodiments of the present invention, the sixth amino acid X in the polypeptide sequence a is α-MeF, and other variables are as defined in the present invention.

[0131] In some embodiments of the present invention, the 12th amino acid X in the polypeptide sequence b is 1, and other variables are as defined in the present invention.

[0132] In some embodiments of the present invention, the 12th amino acid X in the polypeptide sequence b is K, and other variables are as defined in the present invention.

[0133] In some embodiments of the present invention, the 13th amino acid X1 in the polypeptide sequence is α-MeL, and other variables are as defined in the present invention.

[0134] In some embodiments of the present invention, the 13th amino acid X1 in the polypeptide sequence is Y, and other variables are as defined in the present invention.

[0135] In some embodiments of the present invention, the 13th amino acid X1 in the polypeptide sequence is Aib, and other variables are as defined in the present invention.

[0136] In some embodiments of the present invention, the 14th amino acid X7 in the polypeptide sequence is L, and other variables are as defined in the present invention.

[0137] In some embodiments of the present invention, the 14th amino acid X7 in the polypeptide sequence is K, and other variables are as defined in the present invention.

[0138] In some embodiments of the present invention, the 15th amino acid X8 in the polypeptide sequence is D, and other variables are as defined in the present invention.

[0139] In some embodiments of the present invention, the 15th amino acid X8 in the polypeptide sequence is E, and other variables are as defined in the present invention.

[0140] In some embodiments of the present invention, the 17th amino acid X9 in the polypeptide sequence is K, and other variables are as defined in the present invention.

[0141] In some embodiments of the present invention, the 17th amino acid X9 in the polypeptide sequence is Q, and other variables are as defined in the present invention.

[0142] In some embodiments of the present invention, the 17th amino acid X9 in the polypeptide sequence is E, and other variables are as defined in the present invention.

[0143] In some embodiments of the present invention, the 18th amino acid X in the polypeptide sequence 10 is A, and other variables are as defined in the present invention.

[0144] In some embodiments of the present invention, the 18th amino acid X in the polypeptide sequence 10 is Y, and other variables are as defined in the present invention.

[0145] In some embodiments of the present invention, the 19th amino acid X in the polypeptide sequence 11 is Q, and other variables are as defined in the present invention.

[0146] In some embodiments of the present invention, the 19th amino acid X in the polypeptide sequence 11 is A, and other variables are as defined in the present invention.

[0147] In some embodiments of the present invention, the 19th amino acid X in the polypeptide sequence 11 is K, and other variables are as defined in the present invention.

[0148] In some embodiments of the present invention, the 21st amino acid X4 in the polypeptide sequence is K, and other variables are as defined in the present invention.

[0149] In some embodiments of the present invention, the 21st amino acid X4 in the polypeptide sequence is A, and other variables are as defined in the present invention.

[0150] In some embodiments of the present invention, the 21st amino acid X4 in the polypeptide sequence is E, and other variables are as defined in the present invention.

[0151] In some embodiments of the present invention, the 21st amino acid X4 in the polypeptide sequence is α-MeK, and other variables are as defined in the present invention.

[0152] In some embodiments of the present invention, the 21st amino acid X4 in the polypeptide sequence is dK, and other variables are as defined in the present invention.

[0153] In some embodiments of the present invention, the 21st amino acid X4 in the polypeptide sequence is L-Orn, and other variables are as defined in the present invention.

[0154] In some embodiments of the present invention, the 21st amino acid X4 in the polypeptide sequence is L, and other variables are as defined in the present invention.

[0155] In some embodiments of the present invention, the 23rd amino acid X in the polypeptide sequence 12 is 1, and other variables are as defined in the present invention.

[0156] In some embodiments of the present invention, the 23rd amino acid X in the polypeptide sequence 12 is V, and other variables are as defined in the present invention.

[0157] In some embodiments of the present invention, the 24th amino acid X in the polypeptide sequence 13is E, and other variables are as defined in the present invention.

[0158] In some embodiments of the present invention, the 24th amino acid X in the polypeptide sequence 13 is K, and other variables are as defined in the present invention.

[0159] In some embodiments of the present invention, the 24th amino acid X in the polypeptide sequence 13 is Q, and other variables are as defined in the present invention.

[0160] In some embodiments of the present invention, the 25th amino acid X in the polypeptide sequence 14 is Y, and other variables are as defined in the present invention.

[0161] In some embodiments of the present invention, the 25th amino acid X in the polypeptide sequence 14 is W, and other variables are as defined in the present invention.

[0162] In some embodiments of the present invention, the 25th amino acid X in the polypeptide sequence 14 is K, and other variables are as defined in the present invention.

[0163] In some embodiments of the present invention, the 25th amino acid X in the polypeptide sequence 14 is E, and other variables are as defined in the present invention.

[0164] In some embodiments of the present invention, the 25th amino acid X in the polypeptide sequence 14 is F, and other variables are as defined in the present invention.

[0165] In some embodiments of the present invention, the 26th amino acid X in the polypeptide sequence c is L, and other variables are as defined in the present invention.

[0166] In some embodiments of the present invention, the 26th amino acid X in the polypeptide sequence c is F, and other variables are as defined in the present invention.

[0167] In some embodiments of the present invention, the 27th amino acid X in the polypeptide sequence d is L, and other variables are as defined in the present invention.

[0168] In some embodiments of the present invention, the 27th amino acid X in the polypeptide sequence d is 1, and other variables are as defined in the present invention.

[0169] In some embodiments of the present invention, the 28th amino acid X in the polypeptide sequence 15 is E, and other variables are as defined in the present invention.

[0170] In some embodiments of the present invention, the 28th amino acid X in the polypeptide sequence15 is K, and other variables are as defined in the present invention.

[0171] In some embodiments of the present invention, the above X3 is selected from:

[0172] Other variables are as defined in the present invention.

[0173] In some embodiments of the present invention, in the above X3 structure, m is selected from 1 or 2, and other variables are as defined in the present invention.

[0174] In some embodiments of the present invention, p in the above X3 structure is selected from 1, and other variables are as defined in the present invention.

[0175] In some embodiments of the present invention, n in the above X3 structure is selected from 9, and other variables are as defined in the present invention.

[0176] In some embodiments of the present invention, the above X3 is selected from:

[0177] Other variables are as defined in the present invention.

[0178] In some embodiments of the present invention, the above X3 is selected from:

[0179] Other variables are as defined in the present invention.

[0180] In some embodiments of the present invention, the above structural unit for:

[0181] Other variables are as defined in the present invention.

[0182] In some embodiments of the present invention, the above structural unit for:

[0183] Other variables are as defined in the present invention.

[0184] The present invention provides a polypeptide with a modified structure represented by Formula I or a pharmaceutically acceptable salt thereof:

[0185] Formula I: X5X0X6GT FTSDY SIX1X7X8 KX9X 10 X 11 X0 X4FX 12 X 13 X 14 LLX15 GG PSSGA PPPS0

[0186] in:

[0187] X0 is independently selected from Or Aib or alanine (Ala, A), the structure of Aib is

[0188] X1 is independently selected from α-methyl substituted leucine (α-MeLeu, α-MeL) or tyrosine (Tyr, Y), wherein the α-MeL has the structure

[0189] X4 is selected from α-methyl substituted lysine (α-MeLys, α-MeK), which has the structure Or D-lysine (dK), whose structure is Or L-Ornithine (L-Ornithine, L-Orn), its structure is or alanine (Ala, A), lysine (Lys, K), or glutamic acid (Glu, E);

[0190] X5 is selected from tyrosine (Tyr, Y) or histidine (His, H);

[0191] X6 is selected from glutamine (Gln, Q) or histidine (His, H);

[0192] X7 is selected from leucine (Leu, L) or lysine (Lys, K);

[0193] X8 is selected from aspartic acid (Asp, D) or glutamic acid (Glu, E);

[0194] X9 is selected from lysine (Lys, K), glutamine (Gln, Q) or glutamic acid (Glu, E);

[0195] X10 is selected from alanine (Ala, A) or tyrosine (Tyr, Y);

[0196] X11 is selected from lysine (Lys, K), glutamine (Gln, Q) or alanine (Ala, A);

[0197] X12 is selected from valine (Val, V) or isoleucine (Ile, I);

[0198] X13 is selected from lysine (Lys, K), glutamine (Gln, Q) or glutamic acid (Glu, E);

[0199] X14 is selected from lysine (Lys, K), tryptophan (Trp, W), tyrosine (Tyr, Y), glutamic acid (Glu, E) or phenylalanine (Phe, F);

[0200] X15 is selected from lysine (Lys, K) or glutamic acid (Glu, E);

[0201] S0 is selected from (i.e., the C-terminal amino acid is optionally amidated to form a C-terminal primary amide);

[0202] And the compound has the following modifications:

[0203] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure (stapled body) similar to a "staple" structure, wherein i is independently selected from 12, 14, 16, 17, 19, 21, 24 or 25, and j is independently selected from 2, 3, 4, 5 or 7,

[0204] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures Condensation connected;

[0205] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid;

[0206] X3 is selected from:

[0207] R1 and R2 are independently selected from

[0208] m is selected from 1, 2 or 3; p is selected from 1 or 2; n is selected from 8, 9 or 10.

[0209] In some embodiments of the present invention, the above X3 is selected from Other variables are as defined in the present invention.

[0210] In some embodiments of the present invention, the above X3 is selected from Other variables are as defined in the present invention.

[0211] In some embodiments of the present invention, the above X3 is selected from Other variables are as defined in the present invention.

[0212] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0213] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0214] The present invention provides a polypeptide with a modified structure represented by Formula I or a pharmaceutically acceptable salt thereof:

[0215] Formula I: X5X0X6GT FTSDY SIX1X7X8 KX9X 10 X 11 X0 X4FX 12 X 13 X 14 LLX 15 GG PSSGA PPPS0

[0216] in:

[0217] X0 can be independently selected from Or Aib or alanine (Ala, A), the structure of Aib is

[0218] X1 can be independently selected from α-methyl substituted leucine (α-MeLeu, α-MeL) or tyrosine (Tyr, Y), wherein the structure of α-MeL is

[0219] X4 is selected from α-methyl substituted lysine (α-MeLys, α-MeK), which has the structure Or D-lysine (dK), whose structure is Or L-Ornithine (L-Ornithine, L-Orn), its structure is or alanine (Ala, A), lysine (Lys, K), or glutamic acid (Glu, E);

[0220] X5 is selected from tyrosine (Tyr, Y) or histidine (His, H);

[0221] X6 is selected from glutamine (Gln, Q) or histidine (His, H);

[0222] X7 is selected from leucine (Leu, L) or lysine (Lys, K);

[0223] X8 is selected from aspartic acid (Asp, D) or glutamic acid (Glu, E);

[0224] X9 is selected from lysine (Lys, K), glutamine (Gln, Q) or glutamic acid (Glu, E);

[0225] X10 is selected from alanine (Ala, A) or tyrosine (Tyr, Y);

[0226] X11 is selected from lysine (Lys, K), glutamine (Gln, Q) or alanine (Ala, A);

[0227] X12 is selected from valine (Val, V) or isoleucine (Ile, I);

[0228] X13 is selected from lysine (Lys, K), glutamine (Gln, Q) or glutamic acid (Glu, E);

[0229] X14 is selected from lysine (Lys, K), tryptophan (Trp, W), tyrosine (Tyr, Y), glutamic acid (Glu, E) or phenylalanine (Phe, F);

[0230] X15 is selected from lysine (Lys, K) or glutamic acid (Glu, E);

[0231] S0 is selected from (i.e., the C-terminal amino acid is optionally amidated to form a C-terminal primary amide);

[0232] And the compound has the following modifications:

[0233] 1) The amino acid side chains at positions i and i+j in the sequence can be modified to form a modified structure (stapled body) similar to a "staple" structure, wherein i is independently selected from 12, 14, 16, 17, 19, 21, 24 or 25, and j is independently selected from 2, 3, 4, 5 or 7,

[0234] 2) The modification is to modify the amino or carboxyl groups on the side chains of the two amino acid unit structures Condensation connected;

[0235] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid; X3 is selected from:

[0236] m is selected from 1, 2 or 3; p is selected from 1 or 2; n is selected from 8, 9 or 10.

[0237] In some embodiments of the present invention, the amino acids with the same superscript number in the peptide chain sequence of the polypeptide with a modified structure can be modified and connected to form a modified group (staple) similar to a "staple" structure, that is, the side chains of the amino acids at positions i and i+j in the sequence can be modified and connected to form a modified structure (staple) similar to a "staple" structure, wherein i is independently selected from any integer in the range of 10-28, such as 10, 12, 14, 16, 17, 19, 21, 24 or 25, and j is independently selected from any integer in the range of 1-8, such as 1, 2, 3, 4, 5, 7 or 8. The number of the "staple" structure is 1-2. In some embodiments, the first amino acid is at position 25 of the peptide and the second amino acid is at position 28 of the peptide. In some embodiments, the first amino acid is at position 24 of the peptide and the second amino acid is at position 28 of the peptide. In some embodiments, the first amino acid is at position 17 of the peptide and the second amino acid is at position 21 of the peptide. In some embodiments, the first amino acid is at position 16 of the peptide and the second amino acid is at position 19 of the peptide. In some embodiments, the first amino acid is at position 17 of the peptide and the second amino acid is at position 24 of the peptide. In some embodiments, the first amino acid is at position 19 of the peptide and the second amino acid is at position 24 of the peptide. In some embodiments, the first amino acid is at position 21 of the peptide and the second amino acid is at position 28 of the peptide. In some embodiments, the first amino acid is at position 19 of the peptide and the second amino acid is at position 24 of the peptide.

[0238] In some embodiments of the present invention, the polypeptide with a modified structure may have a peptide sequence with up to 0, 1, 2, 3, or 4 amino acid insertions, deletions, modifications, or substitutions. For example, isoleucine (I) at position 12 may be replaced with lysine (K); leucine (L) at positions 26 or 27 may be replaced with isoleucine (I) or phenylalanine (F); X1 at position 13 may be replaced with X0; X0 at position 20 may be replaced with the natural amino acid alanine (A), etc.

[0239] The present invention provides a series of polypeptide sequences as follows:

[0240] YX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 K LL 1 EGG PSSGA PPPS0

[0241] YX0QGT FTSDY SIX1LD KKAQX0 AFI 1 KW LL 1 KGG PSSGA PPPS0

[0242] YX0QGT FTSDY SIX1LD K 1 KAQX0 1KFIEY LLEGG PSSGA PPPS0

[0243] HX0HGT FTSDY SIYLE KKYAX0 EFV 1 KW LL 1 KGG PSSGA PPPS0

[0244] HX0HGT FTSDY SIYLE K 1 KYAX0 1 KFVQW LLEGG PSSGA PPPS0

[0245] YX0QGT FTSDY SIX1LD KKAQX0 AFIQ 1 K LL 1 KGG PSSGA PPPS0

[0246] YX0QGT FTSDY SIX1LD 1 KQA 1 QX0 AFIE 2 K LL 2 KGG PSSGA PPPS0

[0247] YX0QGT FTSDY SIX1LD KEAQX0AFIE 1 K LL 1 KGG PSSGA PPPS0

[0248] HX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 K LL 1 KGG PSSGA PPPS0

[0249] YX0QGT FTSDY SIX1LD KKYQX0 AFIE 1 K LL 1 KGG PSSGA PPPS0

[0250] YX0QGT FTSDY SIX1LE KKAQX0 AFIE 1 K LL 1 KGG PSSGA PPPS0

[0251] HX0HGT FTSDY SIYLE KKYAX0 EFVQ 1 E LL 1 KGG PSSGA PPPS0

[0252] YX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 AND LL 1 KGG PSSGA PPPS0

[0253] YX0QGT FTSDY SIX1LD KKAQX0 AFI 1 EW LL 1 KGG PSSGA PPPS0

[0254] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEF ALLEGG PSSGA PPPS0

[0255] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 EFIEY LLEGG PSSGA PPPS0

[0256] YX0QGT FTSDY SIX1LD K 1 KAQX0 AFI 1 KY LLEGG PSSGA P PPS0

[0257] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEY LLEGG PSSGA P PPS0

[0258] YX0QGT FTSDY SIX1LD KKA 1 KX0 FROM 1 KY LLEGG PSSGA PPPS0

[0259] YX0QGT FTSDY SIX1LD KKAQX0 1 KFIEY LL 1 KGG PSSGA PPPS0

[0260] YX0QGT FTSDY SIX1LD K 1 KAQA 1 X4FIEY LLEGG PSSGA PPPS0

[0261] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 X4FIEY LLEGG PSSGA PPPS0

[0262] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 X4FIEY LLEGG PSSGA PPPS0

[0263] YX0QGT FTSDY SIX1 1 KD K 1 KAQX0 AFIEY LLEGG PSSGA PPPS0

[0264] The superscripts (left superscript) in the sequence refer to the modified amino acid unit structure, and the amino acids with the same superscript number refer to the modified groups (stapled bodies) connected by the modifying groups to form a "staple" structure, such as 1 K and 1 E represents modified lysine and glutamic acid, and the two are connected by a modification group (KE modification); 1 K and 1 K represents a modified lysine, and the two are connected by a modification group (KK modification); 1 K and 1 X4 represents modified lysine and X4, and the two are connected by a modification group (K-X4 modification); wherein X0, X1, X4 and S0 and the modification method are as defined in the present invention.

[0265] The present invention provides a series of polypeptide sequences as follows:

[0266] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEF LLEGG PSSGA PPPS0

[0267] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEF LIEGG PSSGA PPPS0

[0268] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFVEF LIEGG PSSGA PPPS0

[0269] YX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 K FI 1 KGG PSSGA PPPS0

[0270] YX0QGT FTSDY SIX1LD KKAQX0 1 KFIEF LL 1 KGG PSSGA PPPS0

[0271] YX0QGT FTSDY SIX0LD K 1 KAQX0 1 KFIEF LLEGG PSSGA PPPS0

[0272] YX0QGT FTSDY S 1 KX1LD 1 KKAQX0 AFIEF LLEGG PSSGA PPPS0

[0273] wherein X0, X1 and S0 and their modification methods are as defined above.

[0274] The present invention provides a series of polypeptide sequences as follows:

[0275] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEF LLEGG PSSGA PPPS-NH2

[0276] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEF LIEGG PSSGA PPP-NH2

[0277] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFVEF LIEGG PSSGA PPP-NH2

[0278] YX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 K FI 1 KGG PSSGA PPP-NH2

[0279] YX0QGT FTSDY SIX1LD KKAQX0 1 KFIEF LL 1 KGG PSSGA PPP-NH2

[0280] YX0QGT FTSDY SIX0LD K 1 KAQX0 1 KFIEF LLEGG PSSGA PPP-NH2

[0281] YX0QGT FTSDY S 1 KX1LD 1 KKAQX0 AFIEF LLEGG PSSGA PPP-NH2

[0282] Among them, S0 is (ie, the C-terminal amino acid is amidated to form a C-terminal primary amide), X0, X1 and S0 and the modification method are as defined above.

[0283] The present invention provides a series of polypeptide sequences as shown below, wherein the portion X0 is Aib:

[0284] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 KFIEF LLEGG PSSGA PPPS-NH2

[0285] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 KFIEF LIEGG PSSGA PPP-NH2

[0286] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 KFVEF LIEGG PSSGA PPP-NH2

[0287] YX0QGT FTSDY SIX1LD KKAQAib AFIE 1 K FI 1 KGG PSSGA PPP-NH2

[0288] YX0QGT FTSDY SIX1LD KKAQAib 1 KFIEF LL 1 KGG PSSGA PPP-NH2

[0289] YX0QGT FTSDY SIAibLD K 1 KAQAib 1 KFIEF LLEGG PSSGA PPP-NH2

[0290] YX0QGT FTSDY S 1 KX1LD 1 KKAQAib AFIEF LLEGG PSSGA PPP-NH2

[0291] Other variables are as defined above.

[0292] The present invention provides a series of polypeptide sequences as follows, wherein all X0 are Aib and X1 is α-MeL:

[0293] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIEF LLEGG PSSGA PPPS-NH2

[0294] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIEF LIEGG PSSGA PPP-NH2

[0295] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFVEF LIEGG PSSGA PPP-NH2

[0296] YAibQGT FTSDY SIX1LD KKAQAib AFIE 1 K FI 1 KGG PSSGA PPP-NH2

[0297] YAibQGT FTSDY SIX1LD KKAQAib 1 KFIEF LL 1 KGG PSSGA PPP-NH2

[0298] YAibQGT FTSDY SIAibLD K 1 KAQAib 1 KFIEF LLEGG PSSGA PPP-NH2

[0299] YAibQGT FTSDY S 1 KX1LD 1 KKAQAib AFIEF LLEGG PSSGA PPP-NH2

[0300] Other variables are as defined above.

[0301] The present invention provides a series of polypeptide sequences as follows:

[0302] YX0QGT FTSDY SIX1 1 KD K 1KAQX0 AFIEY LLEGG PSSGA PPPS-NH2

[0303] in,

[0304] S0 is (i.e., the C-terminal amino acid is amidated to form a C-terminal primary amide);

[0305] X0 is independently selected from Or Aib, the structure of Aib is

[0306] X1 is α-methyl substituted leucine (α-MeLeu, α-MeL), and its structure is

[0307] The superscripts in the sequence refer to the modified amino acid unit structure, and the amino acids with the same superscript number refer to the modified groups that form a "staple" structure through modification, such as 1 K and 1 K represents a modified lysine, and the two are connected by a modifying group (KK modification);

[0308] The modification is that the amino or carboxyl groups on the side chains of the two amino acid unit structures are Condensation connected;

[0309] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid; X3 is selected from

[0310] m is selected from 1, 2 or 3; p is selected from 1 or 2; n is selected from 8, 9 or 10.

[0311] The present invention provides a series of polypeptide sequences as follows:

[0312] YX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 K LL 1 EGG PSSGA PPPS-NH2

[0313] YX0QGT FTSDY SIX1LD KKAQX0 AFI 1 KW LL 1 KGG PSSGA PPPS-NH2

[0314] YX0QGT FTSDY SIX1LD K 1 KAQX0 1KFIEY LLEGG PSSGA PPPS-NH2

[0315] HX0HGT FTSDY SIYLE KKYAX0 EFV 1 KW LL 1 KGG PSSGA PPPS-NH2

[0316] HX0HGT FTSDY SIYLE K 1 KYAX0 1 KFVQW LLEGG PSSGA PPPS-NH2

[0317] YX0QGT FTSDY SIX1LD KKAQX0 AFIQ 1 K LL 1 KGG PSSGA PPPS-NH2

[0318] YX0QGT FTSDY SIX1LD 1 KQA 1 QX0 AFIE 2 K LL 2 KGG PSSGA PPPS-NH2

[0319] YX0QGT FTSDY SIX1LD KEAQX0AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0320] HX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0321] YX0QGT FTSDY SIX1LD KKYQX0 AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0322] YX0QGT FTSDY SIX1LE KKAQX0 AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0323] HX0HGT FTSDY SIYLE KKYAX0 EFVQ 1 E LL 1 KGG PSSGA PPPS-NH2

[0324] YX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 E LL 1 KGG PSSGA PPPS-NH2

[0325] YX0QGT FTSDY SIX1LD KKAQX0 AFI 1 EW LL 1 KGG PSSGA PPPS-NH2

[0326] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEF LLEGG PSSGA PPPS-NH2

[0327] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 EFIEY LLEGG PSSGA PPPS-NH2

[0328] YX0QGT FTSDY SIX1LD K 1 KAQX0 AFI 1 KY LLEGG PSSGA PPPS-NH2

[0329] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEY LLEGG PSSGA PPPS-NH2

[0330] YX0QGT FTSDY SIX1LD KKA 1 KX0 AFI 1 KY LLEGG PSSGA PPPS-NH2

[0331] YX0QGT FTSDY SIX1LD KKAQX0 1 KFIEY LL 1 KGG PSSGA PPPS-NH2

[0332] YX0QGT FTSDY SIX1LD K 1 KAQA 1 X4FIEY LLEGG PSSGA PPPS-NH2

[0333] YX0QGT FTSDY SIX1LD K 1KAQX0 1 X4FIEY LLEGG PSSGA PPPS-NH2

[0334] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 X4FIEY LLEGG PSSGA PPPS-NH2

[0335] in,

[0336] S0 is (i.e., the C-terminal amino acid is amidated to form a C-terminal primary amide);

[0337] X0 is independently selected from Or Aib, the structure of Aib is

[0338] X1 is α-methyl substituted leucine (α-MeLeu, α-MeL), and its structure is

[0339] X4 can be independently selected from α-methyl substituted lysine (α-MeLys, α-MeK), whose structure is Or D-lysine (dK), whose structure is Or L-Ornithine (L-Ornithine, L-Orn), its structure is

[0340] The superscripts in the sequence refer to the modified amino acid unit structure. Amino acids with the same superscript number refer to the modifying groups connected by the modifying groups to form a "staple" structure, such as 1 K and 1 E represents modified lysine and glutamic acid, and the two are connected by a modification group (KE modification); 1 K and 1 K represents a modified lysine, and the two are connected by a modification group (KK modification); 1 K and 1 X4 represents modified lysine and X4, and the two are connected by a modifying group (K-X4 modification);

[0341] The modification is that the amino or carboxyl groups on the side chains of the two amino acid unit structures are Condensation connected;

[0342] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid;

[0343] X3 is selected from

[0344] m is selected from 1, 2 or 3; p is selected from 1 or 2; n is selected from 8, 9 or 10.

[0345] The present invention also provides a series of polypeptide sequences as follows:

[0346] YX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 K LL 1 EGG PSSGA PPPS-NH2

[0347] YX0QGT FTSDY SIX1LD KKAQX0 AFI 1 KW LL 1 KGG PSSGA PPPS-NH2

[0348] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEY LLEGG PSSGA PPPS-NH2

[0349] HX0HGT FTSDY SIYLE KKYAX0 EFV 1 KW LL 1 KGG PSSGA PPPS-NH2

[0350] HX0HGT FTSDY SIYLE K 1 KYAX0 1 KFVQW LLEGG PSSGA PPPS-NH2

[0351] YX0QGT FTSDY SIX1LD KKAQX0 AFIQ 1 K LL 1 KGG PSSGA PPPS-NH2

[0352] YX0QGT FTSDY SIX1LD 1 KQA 1 QX0 AFIE 2 K LL 2 KGG PSSGA PPPS-NH2

[0353] YX0QGT FTSDY SIX1LD KEAQX0AFIE 1 K LL 1KGG PSSGA PPPS-NH2

[0354] HX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0355] YX0QGT FTSDY SIX1LD KKYQX0 AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0356] YX0QGT FTSDY SIX1LE KKAQX0 AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0357] HX0HGT FTSDY SIYLE KKYAX0 EFVQ 1 E LL 1 KGG PSSGA PPPS-NH2

[0358] YX0QGT FTSDY SIX1LD KKAQX0 AFIE 1 E LL 1 KGG PSSGA PPPS-NH2

[0359] YX0QGT FTSDY SIX1LD KKAQX0 AFI 1 EW LL 1 KGG PSSGA PPPS-NH2

[0360] in,

[0361] X0 is independently selected from Or Aib, the structure of Aib is

[0362] X1 is α-methyl substituted leucine (α-MeLeu, α-MeL), and its structure is

[0363] The superscripts in the sequence refer to the modified amino acid unit structure. Amino acids with the same superscript number refer to the modifying groups connected by the modifying groups to form a "staple" structure, such as 1 K and 1 E represents modified lysine and glutamic acid, and the two are connected by a modification group (KE modification); 1 K and1 K represents a modified lysine, and the two are connected by a modifying group (KK modification).

[0364] The modification is that the amino or carboxyl groups on the side chains of the two amino acid unit structures are Condensation connected;

[0365] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid; X3 is selected from

[0366] m is selected from 1, 2 or 3; p is selected from 1 or 2; n is selected from 8, 9 or 10.

[0367] In some embodiments of the present invention, the peptide chain sequence of the polypeptide with a modified structure is as follows:

[0368] YX0QGT FTSDY SIX1LD KKAQAib AFIE 1 K LL 1 EGG PSSGA PPPS-NH2

[0369] YX0QGT FTSDY SIX1LD KKAQAib AFI 1 KW LL 1 KGG PSSGA PPPS-NH2

[0370] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 KFIEY LLEGG PSSGA PPPS-NH2

[0371] HX0HGT FTSDY SIYLE KKYAAib EFV 1 KW LL 1 KGG PSSGA PPPS-NH2

[0372] HX0HGT FTSDY SIYLE K 1 KYA 1 KFVQW LLEGG PSSGA PPPS-NH2

[0373] YX0QGT FTSDY SIX1LD KKAQAib AFIQ 1 K LL 1 KGG PSSGA PPPS-NH2

[0374] YX0QGT FTSDY SIX1LD 1 KQA 1 QAib AFIE 2 K LL 2 KGG PSSGA PPPS-NH2

[0375] YX0QGT FTSDY SIX1LD KEAQAib AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0376] HX0QGT FTSDY SIX1LD KKAQAib AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0377] YX0QGT FTSDY SIX1LD KKYQAib AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0378] YX0QGT FTSDY SIX1LE KKAQAib AFIE 1 K LL 1 KGG PSSGA PPPS-NH2

[0379] HX0HGT FTSDY SIYLE KKYAAib EFVQ 1 E LL 1 KGG PSSGA PPPS-NH2

[0380] YX0QGT FTSDY SIX1LD KKAQAib AFIE 1 E LL 1 KGG PSSGA PPPS-NH2

[0381] YX0QGT FTSDY SIX1LD KKAQAib AFI 1 EW LL 1 KGG PSSGA PPPS-NH2

[0382] Other variables are as defined in the present invention.

[0383] In some embodiments of the present invention, the peptide chain sequence of the polypeptide with a modified structure is as follows:

[0384] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 KFIEF LLEGG PSSGA PPPS-NH2

[0385] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 EFIEY LLEGG PSSGA PPPS-NH2

[0386] YX0QGT FTSDY SIX1LD K 1 KAQAib AFI 1 KY LLEGG PSSGA PPPS-NH2

[0387] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 KFIEY LLEGG PSSGA PPPS-NH2

[0388] YX0QGT FTSDY SIX1LD KKA 1 KAib AFI 1 KY LLEGG PSSGA PPPS-NH2

[0389] YX0QGT FTSDY SIX1LD KKAQAib 1 KFIEY LL 1 KGG PSSGA PPPS-NH2

[0390] YX0QGT FTSDY SIX1LD K 1 KAQA 1 X4FIEY LLEGG PSSGA PPPS-NH2

[0391] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 X4FIEY LLEGG PSSGA PPPS-NH2

[0392] YX0QGT FTSDY SIX1LD K 1 KAQAib 1 X4FIEY LLEGG PSSGA PPPS-NH2

[0393] Other variables are as defined in the present invention.

[0394] In some embodiments of the present invention, the peptide chain sequence of the polypeptide with a modified structure is as follows:

[0395] YX0QGT FTSDY SIX1 1 KD K 1 KAQAib AFIEY LLEGG PSSGA PPPS-NH2

[0396] Other variables are as defined in the present invention.

[0397] In some embodiments of the present invention, the polypeptide with a modified structure has a peptide chain sequence as shown in any of the following:

[0398] YX0QGT FTSDY SIX1 1 KD K 1 KAQAib EFIEY LLEGG PSSGA PPPS-NH2

[0399] YX0QGT FTSDY SIX1 1 KD K 1 KAQAib AFIEY LLKGG PSSGA PPPS-NH2

[0400] Other variables are as defined in the present invention.

[0401] In some embodiments of the present invention, the polypeptide with a modified structure has X0 all being Aib and X1 being α-MeL, that is, its peptide chain sequence is shown in any of the following:

[0402] YAibQGT FTSDY SIX1 1 KD K 1 KAQAib EFIEY LLEGG PSSGA PPPS-NH2

[0403] YAibQGT FTSDY SIX1 1 KD K 1 KAQAib AFIEY LLKGG PSSGA PPPS-NH2

[0404] Other variables are as defined in the present invention.

[0405] In some embodiments of the present invention, the polypeptide with a modified structure has X0 all being Aib and X1 all being α-MeL, that is, its peptide chain sequence is as follows:

[0406] YAibQGT FTSDY SIX1LD KKAQAib AFIE 1 K LL 1EGG PSSGA PPPS-NH2(SEQ ID NO:3)

[0407] YAibQGT FTSDY SIX1LD KKAQAib AFI 1 KW LL 1 KGG PSSGA PPPS-NH2(SEQ ID NO:2)

[0408] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIEY LLEGG PSSGA PPPS-NH2(SEQ ID NO:1)

[0409] HAibHGT FTSDY SIYLE KKYAAib EFV 1 KW LL 1 KGG PSSGA PPPS-NH2(SEQ ID NO:4)

[0410] HAibHGT FTSDY SIYLE K 1 KYAAib 1 KFVQW LLEGG PSSGA PPPS-NH2(SEQ ID NO:5)

[0411] YAibQGT FTSDY SIX1LD KKAQAib AFIQ 1 K LL 1 KGG PSSGA PPPS-NH2(SEQ ID NO:6)

[0412] YAibQGT FTSDY SIX1LD 1 KQA 1 QAib AFIE 2 K LL 2 KGG PSSGA PPPS-NH2(SEQ ID NO:7)

[0413] YAibQGT FTSDY SIX1LD KEAQAib AFIE 1 K LL 1 KGG PSSGA PPPS-NH2(SEQ ID NO:8)

[0414] HAibQGT FTSDY SIX1LD KKAQAib AFIE 1 K LL 1KGG PSSGA PPPS-NH2 (SEQ ID NO: 9)

[0415] YAibQGT FTSDY SIX1LD KKYQAib AFIE 1 K LL 1 KGG PSSGA PPPS-NH2 (SEQ ID NO: 10)

[0416] YAibQGT FTSDY SIX1LE KKAQAib AFIE 1 K LL 1 KGG PSSGA PPPS-NH2 (SEQ ID NO: 11)

[0417] HAibHGT FTSDY SIYLE KKYAAib EFVQ 1 E LL 1 KGG PSSGA PPPS-NH2 (SEQ ID NO: 12)

[0418] YAibQGT FTSDY SIX1LD KKAQAib AFIE 1 E LL 1 KGG PSSGA PPPS-NH2 (SEQ ID NO: 13)

[0419] YAibQGT FTSDY SIX1LD KKAQAib AFI 1 EW LL 1 KGG PSSGA PPPS-NH2 (SEQ ID NO: 14)

[0420] Other variables are as defined in the present invention.

[0421] In some embodiments of the present invention, the polypeptide with a modified structure has X0 all being Aib, and its peptide chain sequence is as follows:

[0422] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIEF LLEGG PSSGA PPPS-NH2

[0423] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 EFIEY LLEGG PSSGA PPPS-NH2

[0424] YAibQGT FTSDY SIX1LD K 1 KAQAib AFI 1 KY LLEGG PSSGA PPPS-NH2

[0425] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIEY LLEGG PSSGA PPPS-NH2

[0426] YAibQGT FTSDY SIX1LD KKA 1 KAib AFI 1 KY LLEGG PSSGA PPPS-NH2

[0427] YAibQGT FTSDY SIX1LD KKAQAib 1 KFIEY LL 1 KGG PSSGA PPPS-NH2

[0428] YAibQGT FTSDY SIX1LD K 1 KAQA 1 X4KFIEY LLEGG PSSGA PPPS-NH2

[0429] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 X4FIEY LLEGG PSSGA PPPS-NH2

[0430] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 X4FIEY LLEGG PSSGA PPPS-NH2

[0431] Other variables are as defined in the present invention.

[0432] In some embodiments of the present invention, the polypeptide with a modified structure, X1 is α-MeL, and its peptide chain sequence is as follows:

[0433] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIEF LLEGG PSSGA PPPS-NH2

[0434] YAibQGT FTSDY SIX1LD K 1KAQAib 1 EFIEY LLEGG PSSGA PPPS-NH2

[0435] YAibQGT FTSDY SIX1LD K 1 KAQAib AFI 1 KY LLEGG PSSGA PPPS-NH2

[0436] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIEY LLEGG PSSGA PPPS-NH2

[0437] YAibQGT FTSDY SIX1LD KKA 1 KAib AFI 1 KY LLEGG PSSGA PPPS-NH2

[0438] YAibQGT FTSDY SIX1LD KKAQAib 1 KFIEY LL 1 KGG PSSGA PPPS-NH2

[0439] YAibQGT FTSDY SIX1LD K 1 KAQA 1 α-MeKFIEY LLEGG PSSGA PPPS-NH2

[0440] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 d-KFIEY LLEGG PSSGA PPPS-NH2

[0441] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 L-OrnFIEY LLEGG PSSGA PPPS-NH2

[0442] Other variables are as defined in the present invention.

[0443] In some embodiments of the present invention, the polypeptide with a modified structure has X0 all being Aib, and its peptide chain sequence is as follows:

[0444] YAibQGT FTSDY SIX1 1 KD K 1KAQAib AFIEY LLEGG PSSGA PPPS-NH2

[0445] Other variables are as defined in the present invention.

[0446] The present invention also provides a series of polypeptides with modified structures or pharmaceutically acceptable salts thereof:

[0447] YX0QGT FTSDY SIX1LD KKAQX0 1 KFVEF LL 1 KGG PSSGA PPPS0

[0448] YX0QGT FTSDY SIX1LD KKAQX0 1 KFVEF LI 1 KGG PSSGA PPPS0

[0449] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEF LLKGG PSSGA PPPS0

[0450] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIKF LLEGG PSSGA PPPS0

[0451] YX0QGT FTSDY S 1 KX1LD 1 KKAQX0KFIEF LLEGG PSSGA PPPS0

[0452] And the compound has the following modifications:

[0453] The modification is that the amino or carboxyl groups on the side chains of the two amino acid unit structures are Condensation connected;

[0454] X2 is selected from Wherein, "*" indicates the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl groups in the modified amino acid;

[0455] X3 is selected from

[0456] m is selected from 1, 2 or 3; p is selected from 1, 2; n is selected from 8, 9 or 10, and other variables are as defined in the present invention.

[0457] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof has a peptide chain sequence as shown below:

[0458] YX0QGT FTSDY SIX1LD KKAQX0 1 KFVEF LL 1 KGG PSSGA PPPS-NH2

[0459] YX0QGT FTSDY SIX1LD KKAQX0 1 KFVEF LI 1 KGG PSSGA PPPS-NH2

[0460] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIEF LLKGG PSSGA PPPS-NH2

[0461] YX0QGT FTSDY SIX1LD K 1 KAQX0 1 KFIKF LLEGG PSSGA PPPS-NH2

[0462] YX0QGT FTSDY S 1 KX1LD 1 KKAQX0KFIEF LLEGG PSSGA PPPS-NH2

[0463] , other variables are as defined in the present invention.

[0464] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof, wherein the portion X0 is Aib, has a peptide chain sequence as shown below:

[0465] YAibQGT FTSDY SIX1LD KKAQX0 1 KFVEF LL 1 KGG PSSGA PPPS-NH2

[0466] YAibQGT FTSDY SIX1LD KKAQX0 1 KFVEF LI 1 KGG PSSGA PPPS-NH2

[0467] YAibQGT FTSDY SIX1LD K 1 KAQX0 1KFIEF LLKGG PSSGA PPPS-NH2

[0468] YAibQGT FTSDY SIX1LD K 1 KAQX0 1 KFIKF LLEGG PSSGA PPPS-NH2

[0469] YAibQGT FTSDY S 1 KX1LD 1 KKAQX0KFIEF LLEGG PSSGA PPPS-NH2

[0470] Other variables are as defined in the present invention.

[0471] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof, wherein X0 is all Aib and X1 is α-MeL, has a peptide chain sequence as shown below:

[0472] YAibQGT FTSDY SIX1LD KKAQAib 1 KFVEF LL 1 KGG PSSGA PPPS-NH2

[0473] YAibQGT FTSDY SIX1LD KKAQAib 1 KFVEF LI 1 KGG PSSGA PPPS-NH2

[0474] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIEF LLKGG PSSGA PPPS-NH2

[0475] YAibQGT FTSDY SIX1LD K 1 KAQAib 1 KFIKF LLEGG PSSGA PPPS-NH2

[0476] YAibQGT FTSDY S 1 KX1LD 1 KKAQAib KFIEF LLEGG PSSGA PPPS-NH2

[0477] Other variables are as defined in the present invention.

[0478] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof has a peptide chain sequence as shown below:

[0479] YX0QGT FTSDY SIX1 1 KD K 1 KAQX0 AFIQY LLEGG PSSGA PPPS-NH2

[0480] , other variables are as defined in the present invention.

[0481] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof, the X0 portion is Aib ， The peptide chain sequence is shown below:

[0482] YAibQGT FTSDY SIX1 1 KD K 1 KAQX0 AFIQY LLEGG PSSGA PPPS-NH2

[0483] , other variables are as defined in the present invention.

[0484] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof, X0 is all Aib, X1 is α-MeL, and its peptide chain sequence is as follows:

[0485] YAibQGT FTSDY SIX1 1 KD K 1 KAQAib AFIQY LLEGG PSSGA PPPS-NH2

[0486] , other variables are as defined in the present invention.

[0487] In some embodiments of the present invention, the above m is selected from 1 or 2, and other variables are as defined in the present invention.

[0488] In some embodiments of the present invention, the above p is selected from 1, and other variables are as defined in the present invention.

[0489] In some embodiments of the present invention, the above n is selected from 9, and other variables are as defined in the present invention.

[0490] In some embodiments of the present invention, the above X3 is selected from Other variables are as defined in the present invention.

[0491] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0492] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0493] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0494] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0495] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0496] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0497] In some embodiments of the present invention, the above structural unit Other variables are as defined in the present invention.

[0498] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0499] In some embodiments of the present invention, the above structural unit for Other variables are as defined in the present invention.

[0500] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is any of the following, and other variables are as defined in the present invention:

[0501] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is any of the following, and other variables are as defined in the present invention:

[0502] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is any of the following, and other variables are as defined in the present invention:

[0503] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is any of the following, and other variables are as defined in the present invention:

[0504] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is any of the following, and other variables are as defined in the present invention:

[0505] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is any of the following, and other variables are as defined in the present invention:

[0506] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is as follows, and other variables are as defined in the present invention:

[0507] In some specific embodiments of the present invention, the structure of the polypeptide with the modified structure is shown in Table 1 below. The structure of Aib is The α-MeL is an α-methyl substituted leucine, and its structure is The α-MeK is an α-methyl substituted lysine, and its structure is Other variables are as defined in the present invention, for example, superscripts in the sequence refer to modified amino acid unit structures, amino acids with the same superscript number refer to modification groups connected by modification groups to form a "staple" structure, etc.

[0508] Table 1 Peptides with modified structures

[0509] In some specific embodiments of the present invention, the structure of the polypeptide with the modified structure is shown in Table 2 below. The structure of Aib is The α-MeL is an α-methyl substituted leucine, and its structure is The α-MeK is an α-methyl substituted lysine, and its structure is The dK is D-lysine, and its structure is The L-Ornithine or L-Orn is L-ornithine, and its structure is Other variables are as defined in the present invention. For example, the superscripts in the sequence refer to modified amino acid unit structures, and amino acids with the same superscript number refer to modification groups connected by modification groups to form a "staple" (stapled body) structure, etc.

[0510] Table 2 Peptides with modified structures

[0511] In some specific embodiments of the present invention, the structure of the polypeptide with the modified structure is shown in Table 3 below. The structure of Aib is The α-MeL is an α-methyl substituted leucine, and its structure is The α-MeK is an α-methyl substituted lysine, and its structure is Other variables are as defined in the present invention, for example, superscripts in the sequence refer to modified amino acid unit structures, amino acids with the same superscript number refer to modification groups connected by modification groups to form a "staple" structure, etc.

[0512] Table 3 Peptides with modified structures

[0513] In some specific embodiments of the present invention, X1 is α-MeL, and the structure of the polypeptide with the modified structure is shown in Table 4 below. The structure of Aib is The α-MeL is an α-methyl substituted leucine, and its structure is Other variables are as defined in the present invention, for example, superscripts in the sequence refer to modified amino acid unit structures, amino acids with the same superscript number refer to modification groups connected by modification groups to form a "staple" structure, etc.

[0514] Table 4 Peptides with modified structures

[0515] In some specific embodiments of the present invention, X1 is α-MeL, and the structure of the polypeptide with the modified structure is shown in Table 5 below:

[0516] Table 5 Peptides with modified structures

[0517] In some specific embodiments of the present invention, X1 is α-MeL, and the structure of the polypeptide with the modified structure is shown in Table 6 below:

[0518] Table 6 Peptides with modified structures

[0519] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is as follows, and other variables are as defined in the present invention:

[0520] In some specific embodiments of the present invention, X1 is α-MeL, and the structure of the polypeptide with the modified structure is shown in Table 7 below:

[0521] Table 7 Peptides with modified structures

[0522] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof has a peptide chain sequence as shown below:

[0523] YX0QGT FTSDY SIX1 1 KD K 1 KAQX0 KFIEY LLEGG PSSGA PPPS-NH2

[0524] YX0QGT FTSDY SIX1 1 KD K 1 KAQX0 LFIEY LLEGG PSSGA PPPS-NH2

[0525] YX0QGT a-MeFTSDY SIX1 1 KD K 1 KAQX0 AFIEY LLEGG PSSGA PPPS-NH2

[0526] YX0QGT a-MeFTSDY SIX1 1 KD K 1 KAQX0 AFIEY LLKGG PSSGA PPPS-NH2

[0527] , other variables are as defined in the present invention.

[0528] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof, the X0 portion is Aib, and the peptide chain sequence thereof is as follows:

[0529] YAibQGT FTSDY SIX1 1 KD K 1 KAQX0 KFIEY LLEGG PSSGA PPPS-NH2

[0530] YAibQGT FTSDY SIX1 1 KD K 1KAQX0 LFIEY LLEGG PSSGA PPPS-NH2

[0531] YAibQGT a-MeFTSDY SIX1 1 KD K 1 KAQX0 AFIEY LLEGG PSSGA PPPS-NH2

[0532] YAibQGT a-MeFTSDY SIX1 1 KD K 1 KAQX0 AFIEY LLKGG PSSGA PPPS-NH2

[0533] , other variables are as defined in the present invention.

[0534] In some embodiments of the present invention, the polypeptide with a modified structure or a pharmaceutically acceptable salt thereof, X0 is all Aib, X1 is α-MeL, and its peptide chain sequence is as follows:

[0535] YAibQGT FTSDY SIX1 1 KD K 1 KAQAib KFIEY LLEGG PSSGA PPPS-NH2

[0536] YAibQGT FTSDY SIX1 1 KD K 1 KAQAib LFIEY LLEGG PSSGA PPPS-NH2

[0537] YAibQGT a-MeFTSDY SIX1 1 KD K 1 KAQAib AFIEY LLEGG PSSGA PPPS-NH2

[0538] YAibQGT a-MeFTSDY SIX1 1 KD K 1 KAQAib AFIEY LLKGG PSSGA PPPS-NH2

[0539] , other variables are as defined in the present invention.

[0540] In some embodiments of the present invention, the "staple" structure (staple complex) in the above-mentioned polypeptide with a modified structure is as follows, and other variables are as defined in the present invention:

[0541] In some specific embodiments of the present invention, the structures of the polypeptide compounds with modified structures are shown in Table 8 below:

[0542] Table 8 Peptides with modified structures

[0543] The present invention also provides the above-mentioned pharmaceutical composition, comprising as active ingredients a therapeutically effective amount of the above-mentioned polypeptide compound or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable carrier.

[0544] In some embodiments of the present invention, the above-mentioned polypeptide compound or a pharmaceutically acceptable salt thereof or the above-mentioned composition is used in the preparation of a drug for preventing or treating metabolic diseases and related diseases.

[0545] In some embodiments of the present invention, the above-mentioned polypeptide compound or a pharmaceutically acceptable salt thereof or the above-mentioned composition is used in the preparation of a drug for preventing or treating diabetes and related diseases.

[0546] In some embodiments of the present invention, the above-mentioned polypeptide compound or a pharmaceutically acceptable salt thereof or the above-mentioned composition is used in the preparation of a drug for preventing or treating obesity and related diseases.

[0547] In some embodiments of the present invention, the above-mentioned polypeptide compound or a pharmaceutically acceptable salt thereof or the above-mentioned composition is used in the preparation of a drug for preventing or treating NASH (non-alcoholic steatohepatitis) and related diseases.

[0548] Technical Effects

[0549] The polypeptide of the present invention has strong in vitro agonist activity on GLP-1R / GIPR / GCGR, and the compound of the present invention has excellent in vitro and in vivo pharmacokinetic properties; the compound of the present invention has obvious weight loss, blood sugar lowering and blood lipid lowering effects.

[0550] Definition and Description

[0551] Unless otherwise indicated, the following terms and phrases used herein are intended to have the following meanings. The absence of a specific definition for a particular term or phrase should not be construed as indefinite or unclear, but rather should be understood in accordance with its ordinary meaning. When a trade name appears herein, it is intended to refer to the corresponding commercial product or its active ingredient.

[0552] Unless otherwise specified, the “polypeptide”, “peptide” and “polypeptide compound” mentioned in the present invention can be understood by those skilled in the art to have the same meaning in combination with the context.

[0553] Unless otherwise specified, the "polypeptide sequence" and "peptide chain" mentioned in the present invention can be understood by those skilled in the art to have the same meaning in combination with the context.

[0554] Unless otherwise specified, the “staple”, “staple”, “staple assembly” and “staple” mentioned in the present invention can be understood by those skilled in the art to have the same meaning in combination with the context.

[0555] Unless otherwise specified, the example numbers of the compounds in the present invention remain consistent with the order of the compound numbers, that is, the compounds indicated by "Example 1" and "Compound 1" have the same structure.

[0556] The term "pharmaceutically acceptable" as used herein refers to those compounds, materials, compositions and / or dosage forms which, within the scope of sound medical judgment, are suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response or other problems or complications, commensurate with a reasonable benefit / risk ratio.

[0557] The term "pharmaceutically acceptable salt" refers to salts of the compounds of the present invention, prepared by reacting the compounds of the present invention with relatively nontoxic acids or bases. When the compounds of the present invention contain relatively acidic functional groups, base addition salts can be obtained by contacting the compounds with a sufficient amount of base in neat solution or in a suitable inert solvent. Pharmaceutically acceptable base addition salts include sodium, potassium, calcium, ammonium, organic amine, or magnesium salts, or similar salts. When the compounds of the present invention contain relatively basic functional groups, acid addition salts can be obtained by contacting the compounds with a sufficient amount of acid in neat solution or in a suitable inert solvent. Examples of pharmaceutically acceptable acid addition salts include inorganic acid salts such as hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, bicarbonate, phosphoric acid, monohydrogen phosphate, dihydrogen phosphate, sulfuric acid, bisulfate, hydroiodic acid, phosphorous acid, and the like; and organic acid salts such as acetic acid, trifluoroacetic acid, propionic acid, isobutyric acid, maleic acid, malonic acid, benzoic acid, succinic acid, suberic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, tartaric acid, methanesulfonic acid, and pamoic acid, as well as salts of amino acids (such as arginine) and organic acids such as glucuronic acid. Certain specific compounds of the present invention contain both basic and acidic functional groups and can be converted into either base or acid addition salts.

[0558] Pharmaceutically acceptable salts of the present invention can be synthesized by conventional chemical methods from parent compounds containing acid radicals or bases. Generally, such salts are prepared by reacting these compounds in free acid or base form with a stoichiometric amount of a suitable base or acid in water or an organic solvent or a mixture of the two.

[0559] "Amino acid" refers to naturally occurring and synthetic amino acids, as well as amino acid analogs and amino acid mimetics that function similarly to naturally occurring amino acids. Naturally occurring amino acids are those encoded by the genetic code, as well as those that are later modified, for example, hydroxyproline, γ-carboxyglutamate, and O-phosphoserine. Amino acid analogs refer to compounds that have the same basic chemical structure (e.g., an alpha carbon bound to a hydrogen, a carboxyl group, an amino group, and an R group) as naturally occurring amino acids, for example, homoserine, norleucine, methionine sulfoxide, methionine methylsulfonium. Such analogs can have modified R groups (e.g., norleucine) or modified peptide backbones, but retain the same basic chemical structure as naturally occurring amino acids. Amino acid mimetics refer to chemical compounds whose structure is different from the general amino acid chemical structure, but that function similarly to naturally occurring amino acids.

[0560] The natural amino acids and their various expressions described herein are well known to those skilled in the art, and their specific correspondences are shown in the following table:

[0561] Certain other unnatural amino acids, such as 2-aminoisobutyric acid (Aib), correspond to the following table:

[0562] The term "treat" includes inhibiting, slowing, halting or reversing the progression or severity of an existing symptom or condition.

[0563] Unless otherwise indicated, the term "isomer" is intended to include geometric isomers, cis-trans isomers, stereoisomers, enantiomers, optical isomers, diastereomers and tautomers.

[0564] The compounds of the present invention may exist in specific geometric or stereoisomeric forms. The present invention contemplates all such compounds, including cis- and trans-isomers, (-)- and (+)-enantiomers, (R)- and (S)-enantiomers, diastereomers, (D)-isomers, (L)-isomers, and racemic and other mixtures thereof, such as enantiomerically or diastereomerically enriched mixtures, all of which are within the scope of the present invention. Additional asymmetric carbon atoms may be present in substituents such as alkyl groups. All such isomers and mixtures thereof are encompassed within the scope of the present invention.

[0565] Unless otherwise indicated, the term "enantiomer" or "optical isomer" refers to stereoisomers that are mirror images of one another.

[0566] Unless otherwise indicated, the term "cis-trans isomers" or "geometric isomers" arises from the inability to rotate freely about double bonds or single bonds forming ring carbon atoms.

[0567] Unless otherwise indicated, the term "diastereomer" refers to stereoisomers that have two or more chiral centers and that are not mirror images of each other.

[0568] Unless otherwise indicated, "(+)" indicates dextrorotatory, "(-)" indicates levorotatory, and "(±)" indicates racemic.

[0569] Unless otherwise specified, use a solid wedge key. and dotted wedge key To indicate the absolute configuration of a stereocenter, use a straight solid bond and straight dashed key Indicate the relative configuration of stereocenters with a wavy line Indicates a wedge-shaped solid key or dotted wedge key Or use a wavy line Indicates a straight solid bond or straight dashed key

[0570] Unless otherwise indicated, the terms "enriched in one isomer," "isomerically enriched," "enriched in one enantiomer," or "enantiomerically enriched" mean that the content of one isomer or enantiomer is less than 100%, and the content of that isomer or enantiomer is greater than or equal to 60%, or greater than or equal to 70%, or greater than or equal to 80%, or greater than or equal to 90%, or greater than or equal to 95%, or greater than or equal to 96%, or greater than or equal to 97%, or greater than or equal to 98%, or greater than or equal to 99%, or greater than or equal to 99.5%, or greater than or equal to 99.6%, or greater than or equal to 99.7%, or greater than or equal to 99.8%, or greater than or equal to 99.9%.

[0571] Unless otherwise indicated, the term "isomer excess" or "enantiomeric excess" refers to the difference between the relative percentages of two isomers or two enantiomers. For example, if the content of one isomer or enantiomer is 90% and the content of the other isomer or enantiomer is 10%, the isomer or enantiomeric excess (ee value) is 80%.

[0572] Optically active (R)- and (S)-isomers, as well as D and L isomers, can be prepared by chiral synthesis or chiral reagents or other conventional techniques. If one enantiomer of a compound of the present invention is desired, it can be prepared by asymmetric synthesis or derivatization with a chiral auxiliary, wherein the resulting diastereomeric mixture is separated and the auxiliary group is cleaved to provide the pure desired enantiomer. Alternatively, when the molecule contains a basic functional group (such as an amino group) or an acidic functional group (such as a carboxyl group), a diastereomeric salt is formed with an appropriate optically active acid or base, and then the diastereoisomers are resolved by conventional methods known in the art, and then the pure enantiomer is recovered. In addition, the separation of enantiomers and diastereomers is typically accomplished by using chromatography, which employs a chiral stationary phase and is optionally combined with a chemical derivatization method (e.g., carbamate formation from an amine).

[0573] The compounds of the present invention may contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute the compound. For example, the compounds may be labeled with radioactive isotopes, such as tritium ( 3 H), iodine-125( 125 I) or C-14( 14 C). For example, deuterated drugs can be formed by replacing hydrogen with heavy hydrogen. The bond between deuterium and carbon is stronger than the bond between ordinary hydrogen and carbon. Compared with non-deuterated drugs, deuterated drugs have advantages such as reduced toxic side effects, increased drug stability, enhanced efficacy, and prolonged drug biological half-life. All isotopic variations of the compounds of the present invention, whether radioactive or not, are included within the scope of this invention.

[0574] When the linking group is listed without specifying its linking direction, its linking direction is arbitrary, for example, The connecting group L is -MW-, in which case -MW- can connect ring A and ring B in the same direction as the reading order from left to right to form You can also connect ring A and ring B in the opposite direction of reading from left to right to form Combinations of linkers, substituents, and / or variations thereof are permissible only if such combinations result in stable compounds.

[0575] Unless otherwise specified, when a group has one or more connectable sites, any one or more sites of the group can be connected to other groups through chemical bonds. When the chemical bond connection mode is non-positional and there are H atoms at the connectable sites, when the chemical bond is connected, the number of H atoms at the site will decrease accordingly with the number of connected chemical bonds, and become a group with a corresponding valence. The chemical bond connecting the site to other groups can be a straight solid bond. Straight dotted key or wavy lines For example, the straight solid bond in -OCH3 indicates that it is connected to other groups through the oxygen atom in the group; The straight dashed bond in the group indicates that the two ends of the nitrogen atom in the group are connected to other groups; The wavy lines in the phenyl group represent the connection to other groups through the carbon atoms at positions 1 and 2 in the phenyl group.

[0576] Unless otherwise specified, the term “C 1-3 "Alkyl" is used to represent a straight or branched chain saturated hydrocarbon group consisting of 1 to 3 carbon atoms. 1-3 Alkyl groups include C 1-2 and C 2-3 Alkyl, etc.; it can be monovalent (such as methyl), divalent (such as methylene) or polyvalent (such as methine). 1- Examples of 3-alkyl groups include, but are not limited to, methyl (Me), ethyl (Et), propyl (including n-propyl and isopropyl), and the like.

[0577] The structures of the compounds of the present invention can be confirmed by conventional methods well known to those skilled in the art. If the present invention relates to the absolute configuration of the compounds, the absolute configuration can be confirmed by conventional techniques in the art. For example, single crystal X-ray diffraction (SXRD) is used to collect diffraction intensity data on the cultured single crystal using a Bruker D8 venture diffractometer, using CuKα radiation as the light source and scanning mode: After scanning and collecting relevant data, the crystal structure is further analyzed using the direct method (Shelxs97) to confirm the absolute configuration.

[0578] The compounds of the present invention can be prepared by a variety of synthetic methods well known to those skilled in the art, including the specific embodiments listed below, embodiments formed by combining them with other chemical synthesis methods, and equivalent substitutions well known to those skilled in the art. Preferred embodiments include but are not limited to the examples of the present invention.

[0579] The materials and solvents used in the present invention are commercially available.

[0580] Compounds are named according to the conventional nomenclature in the art or using Software naming, commercially available compounds use supplier catalog names.

[0581] In the present invention, compound groups or reagents well known to those skilled in the art can be represented by abbreviations, including but not limited to compound groups: tert-butyloxycarbonyl (BOC), benzyl (Bn), p-toluenesulfonic acid group (Tos), benzyloxycarbonyl (Cbz), fluorenylmethyloxycarbonyl (Fmoc), p-toluenesulfonyl (Ts), allyloxycarbonyl (Alloc), etc.; including but not limited to conventional reagents: dimethyl sulfoxide (DMSO), dichloromethane (DCM), N,N-dimethylformamide (DMF), tetrahydrofuran (THF), trifluoroacetic acid (TFA), N,N'-diisopropylcarbodiimide (DIC), 1-hydroxybenzotriazole (HOBt), benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate (HBTU), 1-hydroxy-7-azabenzotriazole (HOAT), tetrakistriphenylphosphine palladium (Pd(PPh3)4); Fmoc-AEEA-OH: Eicosanedioic acid monotert-butyl ester: N-Boc-N'-Fmoc-Lys-OH: 19-(bis(benzyloxy)phosphoryl)nonadecanoic acid: etc. DETAILED DESCRIPTION

[0582] The present invention is described in detail below by way of examples, but this does not constitute any unfavorable limitation to the present invention. The present invention has been described in detail herein, and specific embodiments thereof are disclosed therein. It will be apparent to those skilled in the art that various changes and modifications can be made to the specific embodiments of the present invention without departing from the spirit and scope of the present invention. The specific synthetic steps described herein also include novel intermediates and methods that can be used to synthesize the polypeptide compounds of the present invention or pharmaceutically acceptable salts thereof. In the specific synthetic steps of the following examples, those skilled in the art can combine them in different ways to prepare the polypeptide compounds of the present invention or their salts.

[0583] In general, the series of polypeptides with modified structures described in the present invention are prepared by a polypeptide solid-phase synthesis method, starting from MBHA resin, using the Fmoc-strategy, and condensing protected amino acids one by one from the C-terminus to the N-terminus according to the peptide sequence (including condensation, deprotection, elution cycle, and removal of side chain protection to form a lactam ring), cleavage, filtration and concentration, precipitation, filtration and drying to obtain a crude branched cyclic peptide cleavage product, which is then purified, concentrated and freeze-dried to obtain the finished product.

[0584] Example 1

[0585] The peptide resin was synthesized using a conventional solid-phase synthesis process. The reaction was carried out by nitrogen bubbling in a solid-phase reaction column with a sintered sieve plate at the bottom. MBHA Resin was used as the starting resin, conventional Fmoc-protected amino acids were added, a DIC / HOBt system was used as the condensing agent, DMF was used as the main reaction solvent, and a 20% PIP-DMF solution was used as the Fmoc removal solvent. Condensation was carried out one by one from the C-terminus to the N-terminus of the peptide backbone. After the backbone synthesis was completed, the -Mtt on the ε-amino group of Fmoc-Lys(Mtt)-OH at position A-23 was removed, and then the side 1 to side 5 positions ((2-2-oxoethyl)-glycine, AEEA, AEEA, γGlu, mono-tert-butyl eicosandioic acid) were condensed in sequence. Then, the ε-amino protecting group of Lys at position A-19 and the carboxyl protecting group of (2-2-oxoethyl)-glycine at position 1 were removed. Then, a condensing agent was added to form a lactam ring to obtain the target peptide resin.

[0586] The specific steps are as follows:

[0587] Step 1: Resin coupling with Fmoc-Rink Linker

[0588] 1. Add 10.2 g (5 mmol) of MBHA Resin (S = 0.49 mmol / g) to a solid phase reaction column. Add 70 mL of DCM and let stand for 20 min to allow the resin to fully swell. Drain the DCM and add 60 mL of DMF to wash the resin by bubbling nitrogen through it. Repeat the above steps once and drain the solvent. Weigh 10.8 g (20 mmol, 4.0 eq) of Fmoc-Rink Linker, dissolve it in 40 mL of DMF, and add it to the above resin. Add 2.78 g (22 mmol, 4.4 eq) of DIC and an additional 10 mL of DMF to the reaction column. Purge nitrogen through the column. Once the resin is completely dissolved, add 2.70 g (20 mmol, 4.0 eq) of HOBt and continue bubbling nitrogen through the reaction column.

[0589] 2. React at 25°C for more than 2 hours. If the sample is negative for ninhydrin test (resin is colorless or light yellow), the reaction is terminated.

[0590] 3. Draw off the reaction liquid, wash with DMF (300 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0591] Step 2: Fmoc-Ser(tBu)-OH coupling

[0592] 1. Add 20% piperidine / DMF (100 mL) to the reaction column and allow nitrogen to bubble for 10 min. Drain the solution until no liquid flows out. Add 20% piperidine / DMF (100 mL) again and continue nitrogen bubbling for 5 min. Take a sample for ninhydrin detection. The resin turns blue.

[0593] 2. Weigh 7.66 g (4.0 eq) of Fmoc-Ser(tBu)-OH, 2.78 g (4.4 eq) of DIC, and 2.70 g (4.0 eq) of HOBt, dissolve them in 60 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure that the resin is evenly inflated.

[0594] 3. React in an environment of 25°C for 2.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0595] 4. Draw off the reaction liquid, wash with DMF (300 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0596] Main chain amino acid coupling steps

[0597] Referring to the Fmoc-Ser(tBu)-OH coupling method and feed equivalents in step 2, the amino acid sequence is sequentially accessed. The order and amino acids containing protecting groups used are as follows:

[0598] Step 3. Side-chain coupling

[0599] 1. Add 300 mL of DMF and 300 mL of DCM to the reaction column in sequence to cross-wash the resin 4 times. After draining the solvent, add 300 mL of 20% hexafluoroisopropanol (HFIP)-DCM solution and bubbling nitrogen twice for 30 minutes each time.

[0600] 2. Drain the waste until no liquid flows out, take a sample for ninhydrin test, and the resin will turn blue;

[0601] 3. Add 300 mL of DCM and 300 mL of DMF in sequence to cross-wash the resin 4 times, and then drain until no liquid flows out.

[0602] 4. Weigh 7.9 g (4.0 eq) of Fmoc-(2-(allyloxy)-2-oxoethyl)glycine (Fmoc-Ida(OAll)-OH), 2.78 g (4.4 eq) of DIC, and 2.70 g (4.0 eq) of HOBt, dissolve them in 100 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0603] 5. React in an environment of 25°C for 2.0 hours, take samples for ninhydrin detection, and the resin should be colorless and transparent;

[0604] 6. Draw off the reaction liquid, wash with DMF (300 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0605] Other branched coupling steps

[0606] Refer to the Fmoc-Ser(tBu)-OH coupling method and feed equivalents in step 2 and add the following compounds in sequence:

[0607] Step 4: Cyclization

[0608] 1. Add 300 mL of DMF and 300 mL of DCM to the reaction column in sequence and wash the resin four times. Drain the waste until no liquid flows out.

[0609] 2. Add 400 ml of this mixed solvent at a volume ratio of DCM: CH3CN: NMP: DEA = 3:3:2:2, and then add 0.58 g (0.1 eq) of Pd(PPh3)4. Bubble nitrogen and react for 10 minutes, then drain until no liquid flows out.

[0610] 3. Repeat the above steps 1 to 2 times;

[0611] 4. Take a sample for ninhydrin test, the resin will turn blue;

[0612] 5. Add 300 mL of DMF and 300 mL of DCM in sequence and cross-wash the resin 8 times;

[0613] 6. Dissolve 2.78 g (4.4 eq) of DIC and 2.70 g (4.0 eq) of HOBt in 150 mL of DMF, add to the reaction column, and react for 48 h under nitrogen. Samples were taken for ninhydrin detection, and the resin was colorless.

[0614] 7. Add 300 mL of DMF and 300 mL of DCM in sequence and cross-wash the resin 8 times;

[0615] 8. Add 200 mL of MeOH and 300 mL of DCM sequentially to cross-wash the resin 4 times;

[0616] 9. Remove the resin and vacuum dry it until the weight stops decreasing. Weigh it to obtain 17.8 g of peptide resin.

[0617] The intermediate (peptide resin) has the following structural formula:

[0618] Boc-Tyr(tBu)-Aib-Gln(Trt)-Gly-Thr(tBu)-Phe-Thr(tBu)-Ser(tBu)-Asp(OtBu)-Tyr(tBu)-Ser(tBu)-Ile-a-MeLeu-Leu-Asp(OtBu)-Lys(Boc)-Lys 17 -Ala-Gln(Trt)-Aib-Lys 21-Phe-Ile-Glu(OtBu)-Tyr(tBu)-Leu-Leu-Glu(OtBu)-Gly-Gly-Pro-Ser(tBu)-Ser(tBu)-Gly-Ala-Pro-Pro-Pro-Ser(tBu)-Rink Linker-MBHA Resin(17,21(Nε(Na-OC-(CH2) 18 -COOtBu)-Glu(ε-OtBu)-AEEA-AEEA)-(2-2-oxoethyl)glycine))

[0619] Step 5. Peptide resin cleavage

[0620] Prepare 250ml of cleavage reagent with a volume ratio of TFA:H2O:EDT:TIS:ArOH = 86.5:5:2.5:1:5. Pre-cool to 10±3°C. Slowly add the resin to the cleavage reagent while stirring, and continue stirring until the reaction temperature stabilizes. Then, maintain the temperature at 18±3°C and continue stirring for 4 hours. Filter the lysate, concentrate it to a viscous state, and precipitate it with 12-15 times the volume of the concentrate with methyl tert-butyl ether. Wash the filtered precipitate, then dry it under reduced pressure at room temperature to obtain 7.9g of crude cyclic peptide.

[0621] Step 6. Chromatographic purification

[0622] The above 7.9 g crude cyclic peptide was dissolved in 10% acetonitrile and 10% acetic acid aqueous solution, and then purified by high performance liquid chromatography using C18 silica gel matrix packing. The fractions with purity greater than 90% were collected and combined. The purification chromatographic system is listed as follows:

[0623] Step 7. Concentration and freeze-drying

[0624] The fraction obtained in the previous step was concentrated to remove acetonitrile, filtered through a 0.22 μm microporous filter membrane, loaded into a hanging bottle freeze dryer, and freeze-dried to obtain 0.93 g of the target polypeptide product (purity: 94.97%); the molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M+4H] / 4 of 1258.7 and a detected value of 1258.7.

[0625] Example 2

[0626] The polypeptide described in Example 2 was obtained by referring to the synthesis of the polypeptide described in Example 1. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1249.7 and a detected value of 1249.4.

[0627] Example 3

[0628] Step 1: Resin coupling with Fmoc-Rink Linker

[0629] 1. Add 10.2 g (5 mmol) of MBHA Resin (S = 0.49 mmol / g) to a solid phase reaction column. Add 70 mL of DCM and let stand for 20 min to allow the resin to fully swell. Drain the DCM and add 60 mL of DMF to wash the resin by bubbling nitrogen through it. Repeat the above steps once and drain the solvent. Weigh 10.8 g (20 mmol, 4.0 eq) of Fmoc-Rink Linker, dissolve it in 40 mL of DMF, and add it to the above resin. Add 2.78 g (22 mmol, 4.4 eq) of DIC and an additional 10 mL of DMF to the reaction column. Purge nitrogen through the column. Once the resin is completely dissolved, add 2.70 g (20 mmol, 4.0 eq) of HOBt and continue bubbling nitrogen through the reaction column.

[0630] 2. React at 25°C for more than 2 hours. If the sample is negative for ninhydrin test (resin is colorless or light yellow), the reaction is terminated.

[0631] 3. Draw off the reaction liquid, wash with DMF (300 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0632] Step 2: Fmoc-Ser(tBu)-OH coupling

[0633] 1. Add 20% piperidine / DMF (100 mL) to the reaction column and allow nitrogen to bubble for 10 min. Drain the solution until no liquid flows out. Add 20% piperidine / DMF (100 mL) again and continue nitrogen bubbling for 5 min. Take a sample for ninhydrin detection. The resin turns blue.

[0634] 2. Weigh 7.66 g (4.0 eq) of Fmoc-Ser(tBu)-OH, 2.78 g (4.4 eq) of DIC, and 2.70 g (4.0 eq) of HOBt, dissolve them in 60 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure that the resin is evenly inflated.

[0635] 3. React in an environment of 25°C for 2.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0636] 4. Draw off the reaction liquid, wash with DMF (300 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0637] Main chain amino acid coupling steps

[0638] Referring to the Fmoc-Ser(tBu)-OH coupling method and feed equivalents in step 2, the amino acid sequence is sequentially accessed. The order and amino acids containing protecting groups used are as follows:

[0639] Step 3. Side-chain coupling

[0640] 1. Add 300 mL of DMF and 300 mL of DCM to the reaction column in sequence to cross-wash the resin 4 times. After draining the solvent, add 300 mL of 20% hexafluoroisopropanol (HFIP)-DCM solution and bubbling nitrogen twice for 30 minutes each time.

[0641] 2. Drain the waste until no liquid flows out, take a sample for ninhydrin test, and the resin will turn blue;

[0642] 3. Add 300 mL of DCM and 300 mL of DMF in sequence to cross-wash the resin 4 times, and then drain until no liquid flows out.

[0643] 4. Weigh 9.05 g (4.0 eq) of Alloc-Lys(Fmoc)-OH, 2.78 g (4.4 eq) of DIC, and 2.70 g (4.0 eq) of HOBt, dissolve them in 100 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0644] 5. React in an environment of 25°C for 2.0 hours, take samples for ninhydrin detection, and the resin should be colorless and transparent;

[0645] 6. Draw off the reaction liquid, wash with DMF (300 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0646] Other branched coupling steps

[0647] Refer to the Fmoc-Ser(tBu)-OH coupling method and feed equivalents in step 2 and add the following compounds in sequence:

[0648] Step 4: Cyclization

[0649] 1. Add 300 mL of DMF and 300 mL of DCM to the reaction column in sequence and wash the resin four times. Drain the waste until no liquid flows out.

[0650] 2. Prepare 400 mL of a mixed solvent with a volume ratio of DCM:CH3CN:NMP:DEA = 3:3:2:2 and add it to the reaction column. Then add 0.58 g (0.1 eq) of Pd(PPh3)4 and react with nitrogen bubbling for 10 min. Drain and drain until no more liquid flows out.

[0651] 3. Repeat the above steps 1 to 2 times;

[0652] 4. Take a sample for ninhydrin test, the resin will turn blue;

[0653] 5. Add 300 mL of DMF and 300 mL of DCM in sequence and cross-wash the resin 8 times;

[0654] 6. Dissolve 2.78 g (4.4 eq) of DIC and 2.70 g (4.0 eq) of HOBt in 150 mL of DMF, add to the reaction column, and react for 48 h under nitrogen. Samples were taken for ninhydrin detection, and the resin was colorless.

[0655] 7. Add 300 mL of DMF and 300 mL of DCM in sequence and cross-wash the resin 8 times;

[0656] 8. Add 200 mL of MeOH and 300 mL of DCM sequentially to cross-wash the resin 4 times;

[0657] 9. Remove the resin and vacuum dry it until the weight stops decreasing. Weigh it to obtain 19.2 g of peptide resin.

[0658] The intermediate (peptide resin) has the following structural formula:

[0659] Boc-Tyr(tBu)-Aib-Gln(Trt)-Gly-Thr(tBu)-Phe-Thr(tBu)-Ser(tBu)-Asp(OtBu)-Tyr(tBu)-Ser(tBu )-Ile-a-MeLeu-Leu-Asp(OtBu)-Lys(Boc)-Lys(Boc)-Ala-Gln(Trt)-Aib-Ala-Phe-Ile-Glu(OtBu)-Lys 25 -Leu-Leu-Glu 28 -Gly-Gly-Pro-Ser(tBu)-Ser(tBu)-Gly-Ala-Pro-Pro-Pro-Ser(tBu)-Rink Linker-MBHA Resin(25,28(Nε(COOH-(CH2) 18 -COOtBu)-Glu(ε-OtBu)-AEEA)-(2-2-oxoethyl)glycine))

[0660] Step 5. Peptide resin cleavage

[0661] Prepare 250mL of cleavage reagent with a volume ratio of TFA:H2O:EDT:TIS:ArOH = 86.5:5:2.5:1:5. Pre-cool to 10±3°C. Slowly add the resin to the cleavage reagent while stirring, and continue stirring until the reaction temperature stabilizes. Then, maintain the temperature at 18±3°C and continue stirring for 4 hours. Filter the lysate, concentrate it to a viscous state, and precipitate it with 12-15 times the volume of the concentrate with methyl tert-butyl ether. Wash the filtered precipitate, then dry it under reduced pressure at room temperature to obtain 8.2g of crude cyclic peptide.

[0662] Step 6. Chromatographic purification

[0663] The above 8.2 g of crude cyclic peptide was dissolved in 10% acetonitrile and 10% acetic acid aqueous solution, and then purified by high performance liquid chromatography using C18 silica gel matrix packing. The fractions with purity greater than 90% were collected and combined. The purification chromatographic system is listed as follows:

[0664] Step 7. Concentration and freeze-drying

[0665] The fraction obtained in the previous step was concentrated to remove acetonitrile, filtered through a 0.22 μm microporous membrane, loaded into a hanging bottle freeze dryer, and freeze-dried to obtain 1.01 g (purity: 94.97%) of the finished product shown in Example 3; the molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1202.6 and a detected value of 1202.6.

[0666] Example 4

[0667] The polypeptide described in Example 4 was obtained by referring to the synthesis of the polypeptide described in Example 1. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1277.7 and a detected value of 1277.6.

[0668] Example 5

[0669] The polypeptide described in Example 5 was obtained by referring to the synthesis of the polypeptide described in Example 1. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1277.7 and a detected value of 1277.5.

[0670] Example 6

[0671] The polypeptide described in Example 6 was obtained by referring to the synthesis of the polypeptide in Example 1. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1122.4 and a detected value of 1122.5.

[0672] Example 7

[0673] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 7 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M+4H] / 4 was 1250.2, and the detected value was 1250.2.

[0674] Example 8

[0675] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 8 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Glu(OAll)-OH, Fmoc-AEEA-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1225.9 and a detected value of 1226.0.

[0676] Example 9

[0677] Referring to the synthesis of the polypeptide in Example 1, the polypeptide described in Example 9 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1218.4 and a detected value of 1218.3.

[0678] Example 10

[0679] Referring to the synthesis of the polypeptide described in Example 3, the polypeptide described in Example 10 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1225.9 and a detected value of 1224.2.

[0680] Example 11

[0681] The polypeptide described in Example 1 was synthesized by referring to the method of Example 1 to obtain the polypeptide described in Example 11. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1244.2 and a detected value of 1242.7.

[0682] Example 12

[0683] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 12 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Glu-OAll, Fmoc-AEEA-OH, Fmoc-AEEA-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1262.2 and a detected value of 1262.2.

[0684] Example 13

[0685] The polypeptide described in Example 1 was synthesized by referring to the method of Example 1 to obtain the polypeptide described in Example 13. The molecular weight of the polypeptide was confirmed by ESI-MS, and the calculated value [M+4H] / 4 was 1244.2, and the detected value was 1244.2.

[0686] Example 14

[0687] Referring to the synthesis of the polypeptide in Example 1, the polypeptide described in Example 14 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1258.5 and a detected value of 1258.4.

[0688] Example 15

[0689] Referring to the synthesis of the polypeptide in Example 1, the polypeptide described in Example 15 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1258.7 and a detected value of 1258.6.

[0690] Example 16

[0691] The polypeptide described in Example 1 was synthesized by referring to the method of Example 1 to obtain the polypeptide described in Example 16. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1258.7 and a detected value of 1258.6.

[0692] Example 17

[0693] Referring to the synthesis of the polypeptide in Example 1, the polypeptide described in Example 17 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1255.2 and a detected value of 1255.1.

[0694] Example 18

[0695] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 18 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M+4H] / 4 was 1235.7, and the detected value was 1234.7.

[0696] Example 19

[0697] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 19 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1250.0, and the detected value was 1249.0.

[0698] Example 20

[0699] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 20 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M+4H] / 4 was 1250.2, and the detected value was 1249.2.

[0700] Example 21

[0701] The peptide resin was synthesized using a conventional solid-phase synthesis process. The reaction was carried out by nitrogen bubbling in a solid-phase reaction column with a sintered sieve plate at the bottom. MBHA Resin was used as the starting resin, conventional Fmoc-protected amino acids were added, a DIC / HOBt system was used as the condensing agent, DMF was used as the main reaction solvent, and a 20% PIP-DMF solution was used as the Fmoc removal solvent. Condensation was carried out one by one from the C-terminus to the N-terminus of the peptide backbone. After the backbone synthesis was completed, the -Mtt on the ε-amino group of Fmoc-Lys(Mtt)-OH at position A-26 was removed, and then the side 1 to side 4 positions ((2-2-oxoethyl)-glycine, AEEA, γGlu, mono-tert-butyl eicosandioic acid) were condensed in sequence. Then, the ε-amino protecting group of Lys at position A-23 and the carboxyl protecting group of (2-2-oxoethyl)-glycine at position 1 were removed. Then, a condensing agent was added to form a lactam ring to obtain the target peptide resin.

[0702] The specific steps are as follows:

[0703] Step 1: Resin activation and deprotection

[0704] 1. Add 15 g (5.1 mmol) of MBHA Resin (S=0.34 mmol / g) to a solid phase reaction column. Add 225 ml of DCM and let stand for 20 min to fully swell the resin. DCM is then drained. 150 ml of DMF is added and washed by bubbling nitrogen through the resin. Repeat the above steps once, draining the solvent. Add 20% piperidine / DMF (150 mL) to the reaction column and bubble nitrogen through the reaction column for 5 min. The mixture is then discarded until no more liquid flows out. 20% piperidine / DMF (150 mL) is added to the reaction column again and nitrogen bubbled through the reaction column for another 15 min. Samples are taken for ninhydrin testing. The resin is grayish red. The reaction solution is then removed and washed seven times with DMF (150 mL), adjusting the pH to 7 for 1 min each time. The mixture is then discarded until no more liquid flows out.

[0705] Step 2: Fmoc-Ser(tBu)-OH coupling

[0706] 1. Weigh 5.75 g (3.0 eq) of Fmoc-Ser(tBu)-OH, 2.52 g (4.0 eq) of DIC, and 2.03 g (3.0 eq) of HOBt, dissolve them in 80 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0707] 2. React in an environment of 25°C for 2.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0708] 3. Draw off the reaction liquid, wash with DMF (150 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0709] Main chain amino acid coupling steps

[0710] Referring to the Fmoc-Ser(tBu)-OH coupling method and feed equivalents in step 2, the amino acid sequence is sequentially accessed. The order and amino acids containing protecting groups used are as follows:

[0711] The AA-11 peptide was obtained.

[0712] Step 3: Deprotection of AA-11 peptide

[0713] 1. To the synthesized AA-11 peptide, DMF (80 mL) was added for activation for 10 min, and the mixture was drained until no liquid flowed out. 20% piperidine / DMF (80 mL) was added to the reaction column, and nitrogen bubbling reaction was carried out for 10 min. The mixture was discharged until no liquid flowed out. 20% piperidine / DMF (80 mL) was added to the reaction column again and nitrogen bubbling reaction was continued for 10 min. The resin was sampled for ninhydrin detection, and the resin was yellow with a tinge of ink; the reaction liquid was removed and washed 8 times with DMF (100 mL), and the pH was adjusted to about 7, each time for 1 min, and the mixture was discharged until no liquid flowed out.

[0714] Step 4: Fmoc-Glu(OtBu)-OH coupling

[0715] 1. Weigh 3.04 g (3.0 eq) of Fmoc-Glu(OtBu)-OH, 1.20 g (4.0 eq) of DIC, and 0.965 g (3.0 eq) of HOBt, dissolve them in 50 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0716] 2. React in an environment of 25°C for 3.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0717] 3. Draw off the reaction liquid, wash with DMF (80 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0718] Main chain amino acid coupling steps

[0719] Referring to the Fmoc-Glu(OtBu)-OH coupling method and feeding order in step 4, the amino acid sequence is sequentially connected. The order and amino acids containing protecting groups used are as follows:

[0720] Step 5. Side-chain coupling

[0721] 1. Add 300 mL of DCM to the reaction column to wash the resin 4 times. After draining the solvent, add 80 mL of 20% hexafluoroisopropanol (HFIP)-DCM solution and bubbling nitrogen for 5 times, each time for 30 minutes.

[0722] 2. Drain the waste until no liquid flows out, take a sample for ninhydrin testing, and the resin will be gray-green;

[0723] 3. Add 80 mL of DCM and 80 mL of DMF in sequence to cross-wash the resin 4 times, and then drain until no liquid flows out.

[0724] 4. Weigh 4.7 g (5.0 eq) of Fmoc-(2-(allyloxy)-2-oxoethyl)glycine (Fmoc-Ida(OAll)-OH), 1.67 g (6.0 eq) of DIC, and 1.49 g (5.0 eq) of HOBt, dissolve them in 100 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0725] 5. React at 25°C for 5.0 hours, take samples for ninhydrin detection, and the resin should be colorless and transparent;

[0726] 6. Draw off the reaction liquid, wash with DMF (80 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0727] Other branched coupling steps

[0728] Refer to the Fmoc-Glu(OtBu)-OH coupling method and feed equivalents in step 4 and add the following compounds in sequence:

[0729] Step 6. Cyclization

[0730] 1. Add 80 mL of DMF and 80 mL of DCM to the reaction column in sequence and wash the resin four times. Drain the waste until no more liquid flows out.

[0731] 2. Prepare 300 mL of a mixed solvent with a volume ratio of DCM:CH3CN:NMP:DEA = 3:3:2:2 and add it to the reaction column. Then add 0.74 g (0.27 eq) of Pd(PPh3)4 and react with nitrogen bubbling for 10 min. Drain and drain until no more liquid flows out.

[0732] 3. Take samples for ninhydrin testing, the resin is yellow with a purple tint;

[0733] 4. Add 80 mL of DMF and 80 mL of DCM in sequence and cross-wash the resin 8 times;

[0734] 5. Dissolve 1.67 g (6.0 eq) of DIC and 1.49 g (5.0 eq) of HOBt in 80 mL of DMF, add to the reaction column, and react for 22 h under nitrogen. Samples were taken for ninhydrin detection, and the resin was colorless.

[0735] 6. Add 80 mL of DMF and 80 mL of DCM in sequence and cross-wash the resin 8 times;

[0736] 7. Add 80 mL of MeOH and 80 mL of DCM sequentially to cross-wash the resin 4 times;

[0737] 8. Remove the resin and vacuum dry it until the weight stops decreasing. Weigh it to obtain 19.3 g of peptide resin.

[0738] The intermediate (peptide resin) has the following structural formula:

[0739] Boc-Tyr(tBu)-Aib-Gln(Trt)-Gly-Thr(tBu)-Phe-Thr(tBu)-Ser(tBu)-Asp(OtBu)-Tyr(tBu)-Ser(tBu)-Ile-a-MeLeu-Lys 14 -Asp(OtBu)-Lys(Boc)-Lys 17 -Ala-Gln(Trt)-Aib-Ala-Phe-Ile-Glu(OtBu)-Tyr(tBu)-Leu-Leu-Glu(OtBu)-Gly-Gly-Pro-Ser(tBu)-Ser(tBu)-Gly-Ala-Pro-Pro-Pro-Ser(tBu)-Rink Linker-MBHA Resin(14,17(Nε(HOOC-(CH2) 18 -COOtBu)-Glu(ε-OtBu)-AEEA)-(2-2-oxoethyl)glycine))

[0740] Step 7. Peptide resin cleavage

[0741] Prepare 289 mL of cleavage reagent with a volume ratio of TFA:H2O:Mpa(Trt)-OH:TIS:ArOH = 82.5:2.5:5:5:5 (TFA:H2O:Mpa(Trt)-OH:TIS:ArOH). Precool to 10±3°C. Slowly add the resin to the cleavage reagent with stirring until the reaction temperature stabilizes. Then, maintain the temperature at 18±3°C and continue stirring for 4 hours. Filter the lysate, concentrate it to a viscous state, and precipitate it with 12-15 times the volume of the concentrate with methyl tert-butyl ether. Wash the filtered precipitate, then dry it under reduced pressure at room temperature to yield 7.5 g of crude cyclic peptide.

[0742] Step 8. Chromatographic purification

[0743] The above 2.1 g crude cyclic peptide was dissolved in 5% acetonitrile and 2% ammonia aqueous solution, and then purified by high performance liquid chromatography using C8 silica gel matrix packing. The fractions with purity greater than 90% were collected and combined. The purification chromatographic system is listed as follows:

[0744] Step 9. Concentration and freeze-drying

[0745] The fraction obtained in the previous step was concentrated to remove acetonitrile, filtered through a 0.22 μm microporous filter membrane, loaded into a hanging bottle freeze dryer, and freeze-dried to obtain 0.133 g of the target polypeptide product (purity: 94.2%); the molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1211.9 and a detected value of 1210.9.

[0746] Example 22

[0747] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 22 was obtained, wherein the protecting amino acids used in the branched-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1246.2, and the detected value was 1245.1.

[0748] Example 23

[0749] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 23 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1246.2, and the detected value was 1245.2.

[0750] Example 24

[0751] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 24 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M+4H] / 4 was 1242.7, and the detected value was 1241.6.

[0752] Example 25

[0753] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 25 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1235.4, and the detected value was 1234.3.

[0754] Example 26

[0755] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 26 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1246.0, and the detected value was 1250.0.

[0756] Example 27

[0757] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 27 was obtained, wherein the protecting amino acids used in the branched-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M+4H] / 4 was 1235.7, and the detected value was 1234.6.

[0758] Example 28

[0759] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 28 was obtained, wherein the protecting amino acids used in the branched-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1235.7, and the detected value was 1238.6.

[0760] Example 29

[0761] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 29 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1242.5, and the detected value was 1241.5.

[0762] Example 30

[0763] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 30 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M+4H] / 4 was 1242.5, and the detected value was 1241.6.

[0764] Example 31

[0765] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 31 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1246.0, and the detected value was 1244.9.

[0766] Example 32

[0767] The polypeptide described in Example 32 was obtained by referring to the synthesis of the polypeptide in Example 1. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1218.2 and a detected value of 1217.4.

[0768] Example 33

[0769] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 33 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1246.0, and the detected value was 1245.9.

[0770] Example 34

[0771] The polypeptide described in Example 34 was obtained by referring to the synthesis of the polypeptide described in Example 1. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1218.2 and a detected value of 1218.1.

[0772] Example 35

[0773] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 35 was obtained, wherein the protecting amino acids used in the branched-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M+4H] / 4 was 1250.0, and the detected value was 1250.0.

[0774] Example 36

[0775] The polypeptide described in Example 36 was obtained by referring to the synthesis of the polypeptide in Example 1. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1222.2 and a detected value of 1222.1.

[0776] Example 37

[0777] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 37 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1226.4 and a detected value of 1226.3.

[0778] Example 38

[0779] A similar synthesis process was used as for the polypeptide in Example 21 above, using MBHA Resin as the starting resin, conventional Fmoc-protected amino acids as the feed, a DIC / HOBt system as the condensing agent, DMF as the main reaction solvent, and a 20% PIP-DMF solution as the Fmoc removal solvent. Condensation reactions were carried out one by one from the C-terminus to the N-terminus of the peptide backbone. After the backbone synthesis was completed, the -Mtt group on the ε-amino group of Fmoc-Lys(Mtt)-OH at position A-26 was removed, and then positions 1 to 4 ((2-2-oxoethyl)-glycine, AEEA, γGlu, mono-tert-butyl eicosanedioate) were condensed in sequence. Then, the ε-amino protecting group of Lys at position A-23 and the carboxyl protecting group of (2-2-oxoethyl)-glycine at position 1 were removed. Then, a condensing agent was added to form a lactam ring to obtain the target peptide resin.

[0780] The specific steps are as follows:

[0781] Step 1: Resin activation and deprotection

[0782] 1. Add 15 g (5.1 mmol) of MBHA Resin (S=0.34 mmol / g) to a solid phase reaction column. Add 225 mL of DCM and let stand for 20 min to fully swell the resin. DCM is then drained. 150 mL of DMF is added and washed by bubbling nitrogen through the resin. Repeat the above steps once, draining the solvent. Add 20% piperidine / DMF (150 mL) to the reaction column and bubble nitrogen through the reaction column for 10 min. The mixture is then discarded until no more liquid flows out. 20% piperidine / DMF (150 mL) is added to the reaction column again and nitrogen bubbled through the reaction column for another 10 min. Samples are taken for ninhydrin testing. The resin is grayish red. Discard the reaction solution and wash it eight times with DMF (150 mL), adjusting the pH to 7 for 1 min each time. The mixture is then discarded until no more liquid flows out.

[0783] Step 2: Fmoc-Ser(tBu)-OH coupling

[0784] 1. Weigh 5.86 g (3.0 eq) of Fmoc-Ser(tBu)-OH, 2.57 g (4.0 eq) of DIC, and 2.07 g (3.0 eq) of HOBt, dissolve them in 80 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0785] 2. React in an environment of 25°C for 2.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0786] 3. Draw off the reaction liquid, wash with DMF (150 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0787] Main chain amino acid coupling steps

[0788] Referring to the Fmoc-Ser(tBu)-OH coupling method and feed equivalents in step 2, the amino acid sequence is sequentially accessed. The order and amino acids containing protecting groups used are as follows:

[0789] The AA-11 peptide was obtained.

[0790] Step 3: Deprotection of AA-11 peptide

[0791] 1. To the synthesized AA-11 peptide, DMF (150 mL) was added for activation for 10 min, and the mixture was drained until no liquid flowed out. 20% piperidine / DMF (150 mL) was added to the reaction column, and nitrogen bubbling reaction was carried out for 10 min. The mixture was discharged until no liquid flowed out. 20% piperidine / DMF (150 mL) was added to the reaction column again and nitrogen bubbling reaction was continued for 10 min. The resin was sampled for ninhydrin detection and was dark yellow. The reaction liquid was removed and washed 8 times with DMF (150 mL), adjusting the pH to about 7, each time for 1 min, and discharged until no liquid flowed out.

[0792] Step 4: Fmoc-Lys(Boc)-OH coupling

[0793] 1. Weigh 7.17 g (3.0 eq) of Fmoc-Lys(Boc)-OH, 2.57 g (4.0 eq) of DIC, and 2.07 g (3.0 eq) of HOBt, dissolve them in 150 mL of DMF, and add them to the reaction column. Blow nitrogen gas into the column and adjust the nitrogen gas flow to ensure that the resin is evenly inflated.

[0794] 2. React in an environment of 25°C for 3.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0795] 3. Draw off the reaction liquid, wash with DMF (150 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0796] Main chain amino acid coupling steps

[0797] Refer to the Fmoc-Lys(Boc)-OH coupling method and feeding order in step 4 to sequentially access the amino acid sequence. The order and amino acids containing protecting groups used are as follows:

[0798] Step 5. Side-chain coupling

[0799] 1. Add 300 mL of DCM to the reaction column to wash the resin 4 times. After draining the solvent, add 150 mL of 20% hexafluoroisopropanol (HFIP)-DCM solution and bubbling nitrogen for 5 times, each time for 30 minutes.

[0800] 2. Drain the waste until no liquid flows out, take a sample for ninhydrin testing, and the resin will be gray-green;

[0801] 3. Add 150 mL of DCM and 150 mL of DMF in sequence to cross-wash the resin 4 times and drain until no liquid flows out.

[0802] 4. Weigh 10.08 g (5.0 eq) of Fmoc-Ida(Oall)-OH, 3.86 g (6.0 eq) of DIC, and 3.45 g (5.0 eq) of HOBt, dissolve them in 150 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0803] 5. React in an environment of 25°C for 3.0 hours, take samples for ninhydrin detection, and the resin should be colorless and transparent;

[0804] 6. Draw off the reaction liquid, wash with DMF (180 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0805] Other branched coupling steps

[0806] Refer to the Fmoc-Ida(Oall)-OH coupling method and feed equivalents in step 5 and sequentially add the following compounds:

[0807] Step 6. Cyclization

[0808] 1. Add 250 mL of DMF and 250 mL of DCM to the reaction column in sequence and wash the resin four times, then drain until no liquid flows out.

[0809] 2. Prepare 300 mL of a mixed solvent with a volume ratio of DCM:CH3CN:NMP:DEA = 3:3:2:2 and add it to the reaction column. Then add 1.59 g (0.27 eq) of Pd(PPh3)4 and react with nitrogen bubbling for 30 min. Drain and drain until no more liquid flows out.

[0810] 3. Take samples for ninhydrin testing, the resin is purple-red;

[0811] 4. Add 250 mL of DMF and 250 mL of DCM in sequence and cross-wash the resin 8 times;

[0812] 5. Dissolve 3.86 g (6.0 eq) of DIC and 3.45 g (5.0 eq) of HOBt in 250 mL of DMF, add the mixture to the reaction column, and allow nitrogen to flow for 22 hours. Sample the mixture for ninhydrin detection, and the resin will be very light purple.

[0813] 6. Add 250 mL of DMF and 250 mL of DCM in sequence and cross-wash the resin 8 times;

[0814] 7. Add 200 mL of MeOH and 200 mL of DCM sequentially and cross-wash the resin 4 times;

[0815] 8. Remove the resin and vacuum dry it until the weight stops decreasing. Weigh it to obtain 32.5 g of peptide resin.

[0816] The intermediate (peptide resin) has the following structural formula:

[0817] Nε(Boc-Tyr(tBu)-Aib-Gln(Trt)-Gly-Thr(tBu)-Phe-Thr(tBu)-Ser(tBu)-Asp(OtBu)-Tyr(tBu)-Ser(tBu)-Ile-a-MeLeu-Lys 14 -Asp(OtBu)-Lys(Boc)-Lys 17 -Ala-Gln(Trt)-Aib-Ala-Phe-Ile-Glu(OtBu)-Tyr(tBu)-Leu-Leu-Lys(Boc)-Gly-Gly-Pro-Ser(tBu)-Ser(tBu)-Gly-Ala-Pro-Pro-Pro-Ser(tBu)-Rink Linker-MBHA Resin(14,17(Nε(HOOC-(CH2) 18 -COOtBu)-Glu(ε-OtBu)-(AEEA)-(2-2-oxoethyl)glycine))

[0818] Step 7. Peptide resin cleavage

[0819] Prepare 500 mL of cleavage reagent (trifluoroacetic acid (TFA), purified water (H2O), triisopropylsilane (TIS), 3-(triphenylmethylthio)propionic acid (Mpa(Trt)-OH), and phenol (ArOH) in a volume ratio of TFA:H2O:Mpa(Trt)-OH:TIS:ArOH = 82.5:2.5:5:5:5. Precool to 10±3°C. Slowly add the resin to the cleavage reagent while stirring. Continue stirring until the reaction temperature stabilizes. Then, maintain the temperature at 18±3°C and continue stirring for 4 hours.

[0820] The lysate was filtered and concentrated to a viscous state, and methyl tert-butyl ether in an amount 12-15 times the volume of the concentrate was used to precipitate it. The precipitate was filtered, washed, and dried under reduced pressure at room temperature to obtain 9.8 g of a crude cyclic peptide.

[0821] Step 8. Chromatographic purification

[0822] 1 / 6 of the 9.8 g crude cyclic peptide was dissolved in 5% acetonitrile and 2% ammonia water, and then purified by high performance liquid chromatography using C18 silica gel matrix packing. The fractions with purity > 90% were collected and combined. The purification chromatographic system is listed as follows:

[0823] Step 9. Concentration and freeze-drying

[0824] The fraction obtained in the previous step was concentrated to remove acetonitrile, filtered through a 0.22 μm microporous filter membrane, loaded into a hanging bottle freeze dryer, and freeze-dried to obtain 144 mg of the target polypeptide product (purity: 96.69%); the molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M+4] / 4 of 1211.6 and a detected value of 1211.5.

[0825] Example 39

[0826] Referring to the synthesis of the polypeptide described in Example 21, the polypeptide described in Example 39 was obtained, wherein the protecting amino acids used in the branched-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M+4H] / 4 was 1239.7, and the detected value was 1239.7.

[0827] Example 40

[0828] Referring to the synthesis of the polypeptide described in Example 21, the polypeptide described in Example 40 was obtained, wherein the protecting amino acids used in the branched-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1254.2, and the detected value was 1254.1.

[0829] Example 41

[0830] Referring to the synthesis of the polypeptide described in Example 38, the polypeptide described in Example 41 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(OAll)-OH, N-Boc-N'-Fmoc-Lys-OH, N-Boc-N'-Fmoc-Lys-OH, Fmoc-Glu-OtBu, and mono-tert-butyl eicosanedioate. The molecular weight of the polypeptide was confirmed by ESI-MS: the calculated value [M+4H] / 4 was 1239.4, and the detected value was 1239.3.

[0831] Example 42

[0832] Referring to the synthesis of the polypeptide described in Example 21, the polypeptide described in Example 42 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1211.6 and a detected value of 1211.5.

[0833] Example 43

[0834] MBHA Resin was used as the starting resin, conventional Fmoc-protected amino acids were fed, a DIC / HOBt system was used as the condensing agent, DMF was used as the main reaction solvent, and a 20% PIP-DMF solution was used as the Fmoc removal solvent. Condensation was carried out one by one from the C-terminus to the N-terminus of the peptide backbone. After the backbone synthesis was completed, the -Mtt on the ε-amino group of Fmoc-Lys(Mtt)-OH at position A-26 was removed, and then the side 1 to side 4 positions ((2-2-oxoethyl)-glycine, AEEA, γGlu, 19-(bis(benzyloxy)phosphoryl)nonadecanoic acid) were condensed in sequence. Then, the ε-amino protecting group of Lys at position A-23 and the carboxyl protecting group of (2-2-oxoethyl)-glycine at position 1 were removed. Finally, a condensing agent was added to form a lactam ring to obtain the target peptide resin.

[0835] The specific steps are as follows:

[0836] Step 1: Resin activation and deprotection

[0837] 1. Add 15 g (5.1 mmol) of MBHA Resin (S=0.34 mmol / g) to a solid phase reaction column. Add 225 mL of DCM and let stand for 20 min to fully swell the resin. DCM is then drained. 150 mL of DMF is added and washed by bubbling nitrogen through the resin. Repeat the above steps once, draining the solvent. Add 20% piperidine / DMF (150 mL) to the reaction column and bubble nitrogen through the reaction column for 10 min. The mixture is then discarded until no more liquid flows out. 20% piperidine / DMF (150 mL) is added to the reaction column again and nitrogen bubbled through the reaction column for another 10 min. Sample ninhydrin is taken for testing. The resin is grayish red. Discard the reaction solution and wash it eight times with DMF (150 mL), adjusting the pH to 7 for 1 min each time. The mixture is then discarded until no more liquid flows out.

[0838] Step 2: Fmoc-Ser(tBu)-OH coupling

[0839] 1. Weigh 5.86 g (3.0 eq) of Fmoc-Ser(tBu)-OH, 2.57 g (4.0 eq) of DIC, and 2.07 g (3.0 eq) of HOBt, dissolve them in 80 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0840] 2. React in an environment of 25°C for 2.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0841] 3. Draw off the reaction liquid, wash with DMF (150 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0842] Main chain amino acid coupling steps

[0843] Referring to the Fmoc-Ser(tBu)-OH coupling method and feed equivalents in step 2, the amino acid sequence is sequentially accessed. The order and amino acids containing protecting groups used are as follows:

[0844] The AA-11 peptide was obtained.

[0845] Step 3: Deprotection of AA-11 peptide

[0846] 1. The synthesized AA-11 peptide was activated by adding DMF (150 mL) for 10 min, and then drained until no liquid flowed out. 20% piperidine / DMF (150 mL) was added to the reaction column, and nitrogen bubbling reaction was carried out for 10 min. The mixture was discharged until no liquid flowed out. 20% piperidine / DMF (150 mL) was added to the reaction column again and nitrogen bubbling reaction was continued for 10 min. The resin was sampled for ninhydrin detection and was dark yellow. The reaction liquid was removed and washed 8 times with DMF (150 mL), adjusting the pH to about 7, each time for 1 min, and discharged until no liquid flowed out.

[0847] Step 4: Fmoc-Glu(tBu)-OH coupling

[0848] 1. Weigh 6.51 g (3.0 eq) of Fmoc-Glu(tBu)-OH, 2.57 g (4.0 eq) of DIC, and 2.07 g (3.0 eq) of HOBt, dissolve them in 150 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0849] 2. React in an environment of 25°C for 3.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0850] 3. Draw off the reaction liquid, wash with DMF (150 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0851] Main chain amino acid coupling steps

[0852] Referring to the Fmoc-Glu(tBu)-OH coupling method and feeding order in step 4, the amino acid sequence is sequentially connected. The order and amino acids containing protecting groups used are as follows:

[0853] Step 5. Side-chain coupling

[0854] 1. Add 300 mL of DCM to the reaction column to wash the resin 4 times. After draining the solvent, add 150 mL of 20% hexafluoroisopropanol (HFIP)-DCM solution and bubbling nitrogen for 5 times, each time for 30 minutes.

[0855] 2. Drain the waste until no liquid flows out, take a sample for ninhydrin testing, and the resin will be gray-green;

[0856] 3. Add 150 mL of DCM and 150 mL of DMF in sequence to cross-wash the resin 4 times and drain until no liquid flows out.

[0857] 4. Weigh 10.08 g (5.0 eq) of Fmoc-Ida(Oall)-OH, 3.86 g (6.0 eq) of DIC, and 3.45 g (5.0 eq) of HOBt, dissolve them in 150 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0858] 5. React in an environment of 25°C for 3.0 hours, take samples for ninhydrin detection, and the resin should be colorless and transparent;

[0859] 6. Draw off the reaction liquid, wash with DMF (180 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0860] Other branched coupling steps

[0861] Refer to the Fmoc-Ida(Oall)-OH coupling method and feed equivalents in step 5 and sequentially add the following compounds:

[0862] Step 6. Cyclization

[0863] 1. Add 250 mL of DMF and 250 mL of DCM to the reaction column in sequence and wash the resin four times, then drain until no liquid flows out.

[0864] 2. Prepare 300 mL of a mixed solvent with a volume ratio of DCM:CH3CN:NMP:DEA = 3:3:2:2 and add it to the reaction column. Then add 1.59 g (0.27 eq) of Pd(PPh3)4 and react with nitrogen bubbling for 30 min. Drain and drain until no more liquid flows out.

[0865] 3. Take samples for ninhydrin testing, the resin is yellow with a purple tint;

[0866] 4. Add 250 mL of DMF and 250 mL of DCM in sequence and cross-wash the resin 8 times;

[0867] 5. Dissolve 3.86 g (6.0 eq) of DIC and 3.45 g (5.0 eq) of HOBt in 250 mL of DMF, add to the reaction column, and react for 23 h under nitrogen. Samples were taken for ninhydrin detection, and the resin was colorless.

[0868] 6. Add 250 mL of DMF and 250 mL of DCM in sequence and cross-wash the resin 8 times;

[0869] 7. Add 200 mL of MeOH and 200 mL of DCM sequentially and cross-wash the resin 4 times;

[0870] 8. Remove the resin and vacuum dry it until the weight stops decreasing. Weigh it to obtain 33 g of peptide resin.

[0871] The intermediate (peptide resin) has the following structural formula:

[0872] Nε(Tyr(tBu)-Aib-Gln(Trt)-Gly-Thr(tBu)-Phe-Thr(tBu)-Ser(tBu)-Asp(OtBu)-Tyr(tBu)-Ser(tBu)-Ile-a-MeLeu-Lys 14 -Asp(OtBu)-Lys(Boc)-Lys 17 -Ala-Gln(Trt)-Aib-Ala-Phe-Ile-Glu(OtBu)-Tyr(tBu)-Leu-Leu-Glu(OtBu)-Gly-Gly-Pro-Ser(tBu)-Ser(tBu)-Gly-Ala-Pro-Pro-Pro-Ser(tBu)-Rink Linker-MBHA Resin(14,17(Nε(HOOC-(CH2) 18 -PO(OBn)2)-Glu(ε-OtBu)-(AEEA)-(2-2-oxoethyl)glycine))

[0873] Step 7. Peptide resin cleavage

[0874] Prepare 500 mL of a cleavage reagent containing trifluoroacetic acid (TFA), purified water (H2O), triisopropylsilane (TIS), 3-(tritylthio)propionic acid (Mpa(Trt)-OH), and phenol (ArOH) in a volume ratio of TFA:H2O:Mpa(Trt)-OH:TIS:ArOH = 82.5:2.5:5:5:5. Precool to 10±3°C. Slowly add the resin to the cleavage reagent while stirring, continuing to stir until the reaction temperature stabilizes. Maintain the temperature at 18±3°C and continue stirring for 8 hours. Filter the lysate, concentrate to a viscous state, and precipitate it with 12-15 times the volume of the concentrate with methyl tert-butyl ether. Wash the filtered precipitate, then dry it under reduced pressure at room temperature to yield 8.8 g of a crude cyclic peptide.

[0875] Step 8. Chromatographic purification

[0876] 2.0 g of the crude cyclic peptide was taken out and dissolved in 5% acetonitrile and 2% ammonia aqueous solution, and then purified by high performance liquid chromatography using C18 silica gel matrix packing. The fractions with purity > 90% were collected and combined. The purification chromatographic system is listed as follows:

[0877] Step 9. Concentration and freeze-drying

[0878] The fraction obtained in the previous step was concentrated to remove acetonitrile, filtered through a 0.22 μm microporous filter membrane, loaded into a hanging bottle freeze dryer, and freeze-dried to obtain 28 mg of the target peptide product (purity: 97.67%); the molecular weight of the peptide was confirmed by ESI-MS, with a calculated value [M] of 1220.9 and a detected value [M+H] of 1219.8.

[0879] Example 44

[0880] The polypeptide described in Example 44 was obtained by referring to the synthesis of the polypeptide in Example 1. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1259.2 and a detected value of 1258.0.

[0881] Example 45

[0882] Referring to the synthesis of the polypeptide described in Example 21, the polypeptide described in Example 45 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value of [M+4H] / 4 of 1248.2 and a detected value of 1248.1.

[0883] Example 46

[0884] Referring to the synthesis of the polypeptide described in Example 1, the polypeptide described in Example 46 was obtained, wherein the protecting amino acids used in the side-chain coupling were, in order, Fmoc-Ida(Oall)-OH, Fmoc-AEEA-OH, Fmoc-AEEA-OH, Fmoc-Glu-OtBu, and 19-(bis(benzyloxy)phosphoryl)nonadecanoic acid. The molecular weight of the polypeptide was confirmed by ESI-MS; the calculated value [M] was 5067.61, and the detected value was 5066.61.

[0885] Example 47

[0886] Referring to the synthesis of the polypeptide of Example 21, the polypeptide of Example 47 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M] of 4900.56 and a detected value of 4900.62.

[0887] Example 48

[0888] Referring to the synthesis of the polypeptide of Example 21, the polypeptide of Example 48 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M] of 4885.56 and a detected value of 4885.50.

[0889] Example 49

[0890] Referring to the synthesis of the polypeptide of Example 21, the polypeptide of Example 49 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M] of 4857.51 and a detected value of 4857.55.

[0891] Example 50

[0892] Referring to the synthesis of the polypeptide of Example 21, the polypeptide of Example 50 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M] of 5002.59 and a detected value of 5002.62.

[0893] Example 51

[0894] Referring to the synthesis of the polypeptide of Example 21, the polypeptide of Example 51 was obtained. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M] of 4856.57 and a detected value of 4856.48.

[0895] Example 52

[0896] MBHA Resin was used as the starting resin, conventional Fmoc-protected amino acids were fed, a DIC / HOBt system was used as the condensing agent, DMF was used as the main reaction solvent, and 20% PIP-DMF solution was used as the Fmoc removal solvent. Condensation was carried out one by one from the C-terminus to the N-terminus of the peptide backbone. After the backbone synthesis was completed, the -Mtt on the ε-amino group of Fmoc-Lys(Mtt)-OH at position A-26 was removed, and then the side 1 to side 4 positions ((2-2-oxoethyl)-glycine, AEEA, N-Boc-N'-Fmoc-Lys-OH, γGlu, mono-tert-butyl eicosandioate) were condensed in sequence. Then, the ε-amino protecting group of Lys at position A-23 and the carboxyl protecting group of (2-2-oxoethyl)-glycine at position 1 were removed. Finally, a condensing agent was added to form a lactam ring to obtain the target peptide resin.

[0897] The specific steps are as follows:

[0898] Step 1: Resin activation and deprotection

[0899] 1. Add 15 g (5.1 mmol) of MBHA Resin (S=0.34 mmol / g) to a solid phase reaction column. Add 225 mL of DCM and let stand for 20 min to fully swell the resin. DCM is then drained. 150 mL of DMF is added and washed by bubbling nitrogen through the resin. Repeat the above steps once, draining the solvent. Add 20% piperidine / DMF (150 mL) to the reaction column and bubble nitrogen through the reaction column for 10 min. The mixture is then discarded until no more liquid flows out. 20% piperidine / DMF (150 mL) is added to the reaction column again and nitrogen bubbled through the reaction column for another 10 min. Samples are taken for ninhydrin testing. The resin is grayish red. Discard the reaction solution and wash it eight times with DMF (150 mL), adjusting the pH to 7 for 1 min each time. The mixture is then discarded until no more liquid flows out.

[0900] Step 2: Fmoc-Ser(tBu)-OH coupling

[0901] 1. Weigh 5.86 g (3.0 eq) of Fmoc-Ser(tBu)-OH, 2.57 g (4.0 eq) of DIC, and 2.07 g (3.0 eq) of HOBt, dissolve them in 80 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0902] 2. React in an environment of 25°C for 2.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0903] 3. Draw off the reaction liquid, wash with DMF (150 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0904] Main chain amino acid coupling steps

[0905] Referring to the Fmoc-Ser(tBu)-OH coupling method and feed equivalents in step 2, the amino acid sequence is sequentially accessed. The order and amino acids containing protecting groups used are as follows:

[0906] The AA-11 peptide was obtained.

[0907] Step 3: Deprotection of AA-11 peptide

[0908] 1. To the synthesized AA-11 peptide, DMF (150 mL) was added for activation for 10 min, and the mixture was drained until no liquid flowed out. 20% piperidine / DMF (150 mL) was added to the reaction column, and nitrogen bubbling reaction was carried out for 10 min. The mixture was discharged until no liquid flowed out. 20% piperidine / DMF (150 mL) was added to the reaction column again and nitrogen bubbling reaction was continued for 10 min. The resin was sampled for ninhydrin detection and was dark yellow. The reaction liquid was removed and washed 8 times with DMF (150 mL), adjusting the pH to about 7, each time for 1 min, and discharged until no liquid flowed out.

[0909] Step 4: Fmoc-Glu(tBu)-OH coupling

[0910] 1. Weigh 6.51 g (3.0 eq) of Fmoc-Glu(tBu)-OH, 2.57 g (4.0 eq) of DIC, and 2.07 g (3.0 eq) of HOBt, dissolve them in 150 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0911] 2. React in an environment of 25°C for 3.0 hours, take samples for ninhydrin detection, and the resin is colorless and transparent;

[0912] 3. Draw off the reaction liquid, wash with DMF (150 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0913] Main chain amino acid coupling steps

[0914] Referring to the Fmoc-Glu(tBu)-OH coupling method and feeding order in step 4, the amino acid sequence is sequentially connected. The order and amino acids containing protecting groups used are as follows:

[0915] Step 5. Side-chain coupling

[0916] 1. Add 300 mL of DCM to the reaction column to wash the resin 4 times. After draining the solvent, add 150 mL of 20% hexafluoroisopropanol (HFIP)-DCM solution and bubbling nitrogen for 5 times, each time for 30 minutes.

[0917] 2. Drain the waste until no liquid flows out, take a sample for ninhydrin testing, and the resin will be gray-green;

[0918] 3. Add 150 mL of DCM and 150 mL of DMF in sequence to cross-wash the resin 4 times and drain until no liquid flows out.

[0919] 4. Weigh 10.08 g (5.0 eq) of Fmoc-Ida(Oall)-OH, 3.86 g (6.0 eq) of DIC, and 3.45 g (5.0 eq) of HOBt, dissolve them in 150 mL of DMF, and add them to the reaction column. Flow nitrogen through the column and adjust the nitrogen flow to ensure uniform swelling of the resin.

[0920] 5. React in an environment of 25°C for 3.0 hours, take samples for ninhydrin detection, and the resin should be colorless and transparent;

[0921] 6. Draw off the reaction liquid, wash with DMF (180 mL) 5 times, 1 min each time, and drain until no liquid flows out.

[0922] Other branched coupling steps

[0923] Refer to the Fmoc-Ida(Oall)-OH coupling method and feed equivalents in step 5 and sequentially add the following compounds:

[0924] Step 6. Cyclization

[0925] 1. Add 250 mL of DMF and 250 mL of DCM to the reaction column in sequence and wash the resin four times, then drain until no liquid flows out.

[0926] 2. Prepare 300 mL of a mixed solvent with a volume ratio of DCM:CH3CN:NMP:DEA = 3:3:2:2 and add it to the reaction column. Then add 1.59 g (0.27 eq) of Pd(PPh3)4 and react with nitrogen bubbling for 30 min. Drain and drain until no more liquid flows out.

[0927] 3. Take samples for ninhydrin testing, the resin is yellow with a purple tint;

[0928] 4. Add 250 mL of DMF and 250 mL of DCM in sequence and cross-wash the resin 8 times;

[0929] 5. Dissolve 3.86 g (6.0 eq) of DIC and 3.45 g (5.0 eq) of HOBt in 250 mL of DMF, add to the reaction column, and react for 22 h under nitrogen. Samples were taken for ninhydrin detection, and the resin was colorless.

[0930] 6. Add 250 mL of DMF and 250 mL of DCM in sequence and cross-wash the resin 8 times;

[0931] 7. Add 200 mL of MeOH and 200 mL of DCM sequentially and cross-wash the resin 4 times;

[0932] 8. Remove the resin and vacuum dry it until the weight stops decreasing. Weigh it to obtain 25.5 g of peptide resin.

[0933] The intermediate (peptide resin) has the following structural formula:

[0934] Nε(Boc-Tyr(tBu)-Aib-Gln(Trt)-Gly-Thr(tBu)-Phe-Thr(tBu)-Ser(tBu)-Asp(OtBu)-Tyr(tBu)-Ser(tBu)-Ile-a-MeLeu-Lys 14 -Asp(OtBu)-Lys(Boc)-Lys 17 -Ala-Gln(Trt)-Aib-Ala-Phe-Ile-Glu(OtBu)-Tyr(tBu)-Leu-Leu-Glu(OtBu)-Gly-Gly-Pro-Ser(tBu)-Ser(tBu)-Gly-Ala-Pro-Pro-Pro-Ser(tBu)-Rink Linker-MBHA Resin(14,17(Nε(HOOC-(CH2) 18 -COOtBu)–Boc(Lys)-Glu(ε-OtBu)-(AEEA)-(2-2-oxoethyl)glycine))

[0935] Step 7. Peptide resin cleavage

[0936] Prepare 500 mL of cleavage reagent with a volume ratio of TFA:H2O:Mpa(Trt)-OH:TIS:ArOH = 82.5:2.5:5:5:5. Precool to 10±3°C. Slowly add the resin to the cleavage reagent with stirring until the reaction temperature stabilizes. Then, maintain the temperature at 18±3°C and continue stirring for 4 hours. Filter the lysate, concentrate it to a viscous state, and precipitate it with 12-15 times the volume of the concentrate with methyl tert-butyl ether. Wash the filtered precipitate, then dry it under reduced pressure at room temperature to obtain 8.6 g of crude cyclic peptide.

[0937] Step 8. Chromatographic purification

[0938] The crude 8.6 cyclic peptide was dissolved in 5% acetonitrile and 2% ammonia water solution, and then purified by high performance liquid chromatography using C18 silica gel matrix packing. The fractions with purity > 90% were collected and combined. The purification chromatographic system is listed as follows:

[0939] Step 9. Concentration and freeze-drying

[0940] The fraction obtained in the previous step was concentrated to remove acetonitrile, filtered through a 0.22 μm microporous filter membrane, loaded into a hanging bottle freeze dryer, and freeze-dried to obtain 1.1 g of the target polypeptide product (purity: 99.12%); the molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M] of 4972.62 and a detected value of 4971.42.

[0941] Example 53

[0942] The polypeptide described in Example 53 was synthesized by referring to the synthesis of the polypeptide described in Example 52. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M] of 4985.61 and a detected value of 4985.42.

[0943] Example 54

[0944] The polypeptide described in Example 54 was synthesized by referring to the synthesis of the polypeptide described in Example 52. The molecular weight of the polypeptide was confirmed by ESI-MS, with a calculated value [M] of 4970.65 and a detected value of 4969.65.

[0945] Biological test data

[0946] Study 1: In vitro GLP-1R / GIPR / GCGR agonist activity assay

[0947] Method 1:

[0948] A: Main materials:

[0949] 1) Cell lines

[0950] This cell line was constructed by Pharmaron. See the table below for details.

[0951] 2) Reagents and consumables

[0952] 3) Instruments

[0953] B. Methods

[0954] Ⅰ) Experimental Materials

[0955] Experimental buffer

[0956] Preparation of detection reagents

[0957] II) Experimental methods

[0958] a) Preparation of compound plates:

[0959] The test compound was diluted 5-fold in 10 spots, with the starting concentration being 200 nM.

[0960] b) Preparation of cell suspension

[0961] 1) The cell lines were cultured in complete culture medium at 37°C and 5% CO2.

[0962] 2) After TrypLE digestion, the cells were resuspended in experimental buffer and seeded into CulturPlate-384 cell culture plates at a seeding density of 2000 cells per well in a seeding volume of 15 μL per well.

[0963] c) Agonist activity assay

[0964] 1) Freeze-thaw Eu-cAMP tracer and dilute it 50-fold with detection buffer; freeze-thaw Ulight-anti-cAMP and dilute it 150-fold with detection buffer.

[0965] 2) Add 5 μL of the test compound to each experimental well of the CulturPlate-384 cell culture plate, centrifuge at 200 g for 30 seconds, and let stand at 37°C for 30 minutes.

[0966] 3) Add 10 μL of Eu-cAMP tracer to each experimental well, and then add 10 μL of Uligh-anti-cAMP to each experimental well.

[0967] 4) Centrifuge the reaction plate at 200 g for 30 seconds at room temperature and let it stand at 25°C for 1 hour.

[0968] 5) Data were collected using Envision 2105, with excitation light at 340 nm and emission light at 665 nm and 615 nm.

[0969] C Experimental Results

[0970] Conclusion: The polypeptide compounds of the present invention exhibit potent agonist activity against GLP-1R / GIPR / GCGR, generally superior to or comparable to that of LY3437943. The introduction of the "staple" structure and its location in the ligands specifically influences the activity of the peptides. Furthermore, the results were consistent in repeated experiments and with other compounds. In optimal conditions, compared to the activity of the control, LY3437943, the compounds of the present invention exhibit 0.05- to 5-fold higher agonist activity against GLP-1R, 0.1- to 5-fold higher agonist activity against GIPR, and 0.2- to 5-fold higher agonist activity against GCGR.

[0971] In summary, the compounds of the present invention have superior in vitro GLP-1R / GIPR / GCGR agonist activity, and are generally better than or not worse than the reference substance LY3437943.

[0972] Study 2: Pharmacokinetic properties of the compound in cynomolgus monkeys

[0973] A. Experimental Purpose

[0974] Pharmacokinetics of test compounds in cynomolgus monkeys

[0975] B. Experimental Operation

[0976] Non-juvenile male cynomolgus monkeys (3 per compound) were used; whole blood was collected at 1h, 2h, 4h, 8h, 16h, 24h, 48h, 72h, 120h, 168h, and 240h after administration to prepare plasma. Drug concentrations were analyzed by LC-MS / MS, and pharmacokinetic parameters were calculated using Phoenix WinNonlin software.

[0977] C. Experimental Results

[0978] The experimental results are shown in the following table.

[0979] Pharmacokinetic test results in cynomolgus monkeys

[0980] Conclusion: In the pharmacokinetic properties of cynomolgus monkeys, the half-life of the compound of the present invention is T 1 / 2The half-life T is greater than 70h, which is significantly better than that of LY-3437943. 1 / 2 and exposure, and its overall advantages are no worse than LY-3437943.

[0981] Furthermore, in repeated experiments, the experimental results obtained by testing other compounds showed the same trend. In the best case, compared with the reference substance LY3437943, the half-life T 1 / 2 and exposure value AUC INF It is 1.1 to 2.5 times that of LY3437943, and its overall properties are better than LY3437943.

[0982] In addition, in further studies, the pharmacokinetic properties of the compound of the present application were tested in C57BL / 6 mice and SD rats. The experimental results were consistent with the pharmacokinetic properties in cynomolgus monkeys, and both showed better pharmacokinetic properties in mice and rats. Compared with the LY-3437943 compound, it has a better or equivalent half-life T 1 / 2 and exposure.

[0983] Experiment 3: Human kidney S9 metabolic stability test

[0984] A. Experimental Purpose

[0985] Evaluate the metabolic stability of compounds in the human kidney to determine whether the drug will be degraded by renal metabolic enzymes, thereby affecting its efficacy and pharmacokinetics.

[0986] B. Experimental Operation

[0987] 1. Prepare relevant solutions.

[0988] 2.a) With cofactors (NADPH & UDPGA): Add NADPH and UDPGA during incubation. The final concentrations of KS9 Fractions, NADPH, and UDPGA are 1 mg / mL, 1 mM, and 2 mM, respectively. b) Without cofactors (NADPH & UDPGA): Add HO to the culture medium. The final concentration of KS9 Fractions is 1 mg / mL. Preheat the mixture at 37°C for 10 minutes.

[0989] 3. Initiate the reaction by adding a 20 μM control compound or a 100 μM test compound solution. 7-Hydroxycoumarin and raloxifene were used as positive controls in this study. The final concentration of the positive control compound was 0.2 μM, and the final concentration of the test compound was 1 μM. Incubate the culture in a 37°C water bath.

[0990] 4. At 0.5, 5, 15, 30, and 60 min, aliquot the reaction solution and stop the reaction with acetonitrile. Centrifuge the samples for 30 min. Mix the supernatant with ultrapure water and use for LC-MS / MS analysis.

[0991] 5. Data Analysis: All calculations were performed using Microsoft Excel. Peak areas and slopes were determined from the extracted ion chromatograms.

[0992] C. Experimental Results

[0993] Table 4 Metabolic stability test results of kidney S9

[0994] Conclusion: The compounds of the present invention have excellent in vitro pharmacokinetic properties.

[0995] Experiment 4: Pharmacodynamic study of the compound in the DIO obese mouse model

[0996] Experimental purpose: To evaluate the effects of repeated administration of the test substance (compound) on body weight and glucose and lipid metabolism.

[0997] In this experiment, mice that had been induced to eat a high-fat diet (Research Diets: D12492) for 8 weeks starting from 4-5 weeks of age were used as test animals. The animals were grouped according to their body weight and fasting blood glucose levels. The average body weight of the model animals was 47.2±0.3g, and the average body weight of the control animals was 27.9±0.3g. The average fasting blood glucose of the model animals was 8.8±0.2mmol / L, and the average fasting blood glucose of the control animals was 6.0±0.2mmol / L. Six animals were administered subcutaneously immediately after grouping, once every three days for 22 consecutive days. Both the normal control group and the model group were given vehicle (20 mM citric acid buffer). Body weight and food intake were measured twice a week. Fasting blood glucose was measured on D10 and D20 after administration, an OGTT test was performed on D20, and blood was collected on D23 to test liver function indicators (ALT, AST, ALP) and serum lipid metabolism indicators (TC, TG, HDL, LDL). Liver tissue was taken to calculate organ index, liver lipid metabolism indicators (liver TC, TG) were measured, and liver tissue was pathologically examined (HE, oil red) to evaluate the effects of the test substances on body weight and glucose and lipid metabolism in the high-fat diet-induced obese mouse model.

[0998] Data for each animal experiment are presented as mean ± standard error (X ± SEM). P < 0.05 was considered statistically significant. All statistical analyses were performed using Graphpad 8.0 software.

[0999] Effects of Table 2 on body weight changes of DIO mice

[1000] Conclusion: The results in the table indicate that the compounds of this invention have a significant weight loss effect, demonstrating comparable or superior weight loss efficacy to that of LY3437943. Furthermore, experimental results obtained from testing other compounds of this invention demonstrate comparable or superior weight loss efficacy to that of LY3437943.

[1001] Effects of Table 2 Compounds on Fasting Blood Glucose Changes in DIO Mice

[1002] Conclusion: As can be seen from the table, the compounds of the present invention have significant hypoglycemic effects, demonstrating comparable or superior hypoglycemic effects to those of LY3437943. Furthermore, experimental results obtained from testing other compounds of the present invention demonstrate comparable or superior hypoglycemic effects to those of LY3437943.

[1003] Table 2 Effects of compounds on liver-to-body ratio in DIO mice

[1004] Conclusion: The results in the table indicate that the compounds of this invention significantly improve the liver-to-body ratio and exhibit comparable or even superior hypoglycemic effects to those of LY3437943. Furthermore, experimental results obtained from testing other compounds of this invention demonstrate comparable or even superior effects to those of LY3437943 in improving the liver-to-body ratio.

[1005] Table 2 Effects of compounds on changes in liver parameters in DIO mice

[1006] Conclusion: From the results in the table, the compounds of the present invention have a significant effect on lowering liver triglycerides. In addition, the experimental results obtained by testing other compounds of the present invention show that they have an effect comparable to or better than LY3437943 in lowering liver triglycerides.

[1007] Further, referring to a similar experimental protocol, the compounds of Example 38 and Example 52 were tested, and the effects on the body weight changes of DIO mice were as follows:

[1008] Effects of Table 2 on body weight changes of DIO mice

[1009] Conclusion: From the results in the table, the compounds of Example 38 and Example 52 of the present invention also have obvious weight loss effects, and show weight loss effects comparable to or better than LY3437943.

[1010] In addition, the pharmacodynamics of the compounds of the present application were further studied in an IPGTT test. The results showed that compared with the vehicle group, the compounds of the present invention exhibited excellent hypoglycemic ability, which showed a hypoglycemic effect comparable to or better than that of LY3437943.

[1011] In summary, this application has newly designed and synthesized a series of peptide compounds with modified structures. These peptides exhibit strong in vitro agonist activity against GLP-1R / GIPR / GCGR, excellent in vitro and in vivo pharmacokinetic properties, good stability, and significant weight loss, glucose-lowering, and lipid-lowering effects. The peptide compounds of this invention have promising drug development prospects as long-acting GLP-1 / GIP / GCGR multi-agonists.

Claims

1. A polypeptide with a modified structure and its pharmaceutically acceptable salts, and the polypeptide sequence is shown as Formula Z-3: X5X0X6GT FTSDY SIX1X7X8 KX9X 10 X 11 X0 X4FX 12 X 13 X 14 LLX 15 GG PSSGA PPPS0 Formula Z-3 Wherein: X5 is selected from tyrosine (Tyr, Y) or histidine (His, H); X0 is independently selected from or Aib or alanine (Ala, A); X6 is selected from glutamine (Gln, Q) or histidine (His, H); X1 can be independently selected from α-methyl-substituted leucine (α-MeLeu, α-MeL) or tyrosine (Tyr, Y); X7 is selected from leucine (Leu, L) or lysine (Lys, K); X8 is selected from aspartic acid (Asp, D) or glutamic acid (Glu, E); X9 is selected from lysine (Lys, K), glutamine (Gln, Q) or glutamic acid (Glu, E); X 10 selected from alanine (Ala, A) or tyrosine (Tyr, Y); X 11 selected from lysine (Lys, K), glutamine (Gln, Q) or alanine (Ala, A); X4 is selected from α-methyl-substituted lysine (α-MeLys, α-MeK), D-lysine (d-K), L-ornithine (L-Ornithine, L-Orn), alanine (Ala, A), lysine (Lys, K) or glutamic acid (Glu, E); X 12 selected from valine (Val, V) or isoleucine (Ile, I); X 13 selected from lysine (Lys, K), glutamine (Gln, Q) or glutamic acid (Glu, E); X 14 selected from lysine (Lys, K), tryptophan (Trp, W), tyrosine (Tyr, Y), glutamic acid (Glu, E) or phenylalanine (Phe, F); X 15 selected from lysine (Lys, K) or glutamic acid (Glu, E); S0 is selected from (i.e., the C-terminal amino acid is optionally amidated to a C-terminal primary amide); and the polypeptide compound has the following modifications: 1) The amino acid side chains at the i position and the i + j position in the sequence can be connected by modification to form a modified structure (stapler) similar to a "stapler" structure, where i is independently selected from 14, 17, 19, 21, 24 or 25, and j is independently selected from 3, 4, 5 or 7, 2) The modification is that the amino group or carboxyl group on the side chain of the two-amino acid unit structure reacts with condensed and linked; X2 is selected from wherein, "*" represents the position connected to X3, and both ends are the positions connected to the corresponding amino or carboxyl group in the modified amino acid; X3 is selected from: R1 and R2 are independently selected from m is selected from 1, 2 or 3; p is selected from 1 or 2; n is selected from 8, 9 or 10.

2. The polypeptide according to claim 1 and its pharmaceutically acceptable salts, characterized in that, In the polypeptide sequence, S0 is 3. The polypeptide according to claim 1 and its pharmaceutically acceptable salts, characterized in that, The amino acid X0 at the 2nd position in the polypeptide sequence is selected from Aib.

4. The polypeptide according to claim 1 and its pharmaceutically acceptable salts, characterized in that, The amino acid X0 at the 20th position in the polypeptide sequence is selected from Aib or A.

5. The polypeptide according to any one of claims 1-2 and its pharmaceutically acceptable salts, characterized in that, The polypeptide sequence is selected from the following sequences: YAibQGT FTSDY SIα-MeLLD KKAQAib KFIEY LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 1) YAibQGT FTSDY SIα-MeLLD KKAQAib AFIKW LLKGG PSSGA PPPS-NH2 (SEQ ID NO: 2) YAibQGT FTSDY SIα-MeLLD KKAQAib AFIEK LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 3) HAibHGT FTSDY SIYLE KKYAAib EFVKW LLKGG PSSGA PPPS-NH2 (SEQ ID NO: 4) HAibHGT FTSDY SIYLE KKYAAib KFVQW LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 5) YAibQGT FTSDY SIα-MeLLD KKAQAib KFIEF LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 15) YAibQGT FTSDY SIα-MeLLD KKAQAib EFIEY LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 16) YAibQGT FTSDY SIα-MeLLD KKAQAib AFIKY LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 17) YAibQGT FTSDY SIα-MeLLD KKAQAib KFIEY LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 18) YAibQGT FTSDY SIα-MeLLD KKAKAib AFIKY LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 19) YAibQGT FTSDY SIα-MeLLD KKAQAib KFIEY LLKGG PSSGA PPPS-NH2 (SEQ ID NO: 20) YAibQGT FTSDY SIα-MeLLD KKAQA α-MeKFIEY LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 21) YAibQGT FTSDY SIα-MeLLD KKAQAib d-KFIEY LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 22) YAibQGT FTSDY SIα-MeLLD KKAQAib L-OrnFIEYLLEGG PSSGA PPPS-NH2 (SEQ ID NO: 23) YAibQGT FTSDY SIα-MeLKD KKAQAib AFIEY LLEGG PSSGA PPPS-NH2 (SEQ ID NO: 24).

6. The polypeptide according to claim 5 and its pharmaceutically acceptable salts, characterized in that, i is 14 and j is 3.

7. The polypeptide according to claim 5 and its pharmaceutically acceptable salts, characterized in that, i is 17 and j is 4.

8. The polypeptide according to claim 5 and its pharmaceutically acceptable salts, characterized in that, i is 17 and j is 7.

9. The polypeptide according to claim 5 and a pharmaceutically acceptable salt thereof, characterized in that, i is 19 and j is 5.

10. The polypeptide according to claim 5 and its pharmaceutically acceptable salts, characterized in that, i is 21 and j is 7.

11. The polypeptide according to claim 5 and its pharmaceutically acceptable salts, characterized in that, i is 24 and j is 4.

12. The polypeptide according to claim 5 and its pharmaceutically acceptable salts, characterized in that, i is 25 and j is 4.

13. The polypeptide according to claim 1 and its pharmaceutically acceptable salts, characterized in that, m is selected from 1, 2.

14. The polypeptide according to claim 1 and its pharmaceutically acceptable salts, characterized in that, p is selected from 1.

15. The polypeptide according to claim 1 and its pharmaceutically acceptable salts, characterized in that, n is selected from 9.

16. The polypeptide according to claim 1 and its pharmaceutically acceptable salts, characterized in that, X3 is selected from: Further preferably:

17. The polypeptide according to claim 1 and a pharmaceutically acceptable salt thereof, characterized in that, Structural unit selected from: More preferably:

18. The polypeptide according to claim 1 and its pharmaceutically acceptable salts, characterized in that, The staple body structure is selected from:

19. The polypeptide compound shown by the following formula and its pharmaceutically acceptable salts:

20. The polypeptide according to any one of claims 1-20 and its pharmaceutically acceptable salts, characterized in that, The salt can be a salt formed with the following acids: inorganic acids include hydrochloric acid, hydrobromic acid, nitric acid, carbonic acid, bicarbonate, phosphoric acid, monohydrogen phosphate, dihydrogen phosphate, sulfuric acid, bisulfate, hydroiodic acid, phosphorous acid; organic acids include acetic acid, trifluoroacetic acid, propionic acid, isobutyric acid, maleic acid, malonic acid, benzoic acid, succinic acid, suberic acid, fumaric acid, lactic acid, mandelic acid, phthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, citric acid, tartaric acid, methanesulfonic acid, mesylate, pamoic acid, arginine, glucuronic acid.

21. A pharmaceutical composition, characterized in that The pharmaceutical composition contains the polypeptide or its pharmaceutically acceptable salt according to any one of claims 1-20.

22. Use of the polypeptide or its pharmaceutically acceptable salt according to any one of claims 1-20, and the pharmaceutical composition according to claim 21 in the preparation of a drug for treating metabolic diseases and related diseases.

23. According to the use of claim 22, the metabolic diseases include diabetes, obesity and non-alcoholic steatohepatitis and related diseases.

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