Fatty acid chain for modifying GLP-1 / GIP / glucagon receptor agonist and application of fatty acid chain

Abstract

The invention discloses a fatty acid chain for modifying a GLP-1 / GIP / glucagon receptor stimulant and application thereof, the fatty acid chain is used for modifying the receptor stimulant by improving the aspects of the carbon chain length, the functional group type and the like of the fatty acid chain, the treatment effect of the receptor stimulant on the aspects of reducing blood sugar and reducing body weight is remarkably improved, and the fatty acid chain can be used for modifying the GLP-1 / GIP / glucagon receptor stimulant. The fatty acid chain and the receptor agonist modified by the fatty acid chain can reduce the blood sugar level and improve the sugar tolerance; meanwhile, the effects of controlling appetite, ingestion and calorie intake, increasing energy consumption, preventing weight gain, promoting weight loss and reducing overweight are achieved; in addition, the fatty acid chain and the receptor agonist modified by the fatty acid chain have a long half-life period, and the action time of drugs in vivo can be effectively prolonged.

Description

Technical Field

[0001] The present invention relates to the field of compound synthesis, and in particular to a fatty acid chain for modifying a GLP-1 / GIP / glucagon receptor agonist and applications thereof. Background Art

[0002] With social development and changes in lifestyle, the number of overweight and obese people worldwide continues to increase. Obesity can lead to metabolic abnormalities, which in turn cause numerous health problems, such as cardiovascular disease and type 2 diabetes. Type 2 diabetes, the most common form of diabetes, is caused by impaired β-cell function, relative insulin deficiency, and insulin resistance, and is also a common cause of non-alcoholic fatty liver disease. Incretins, secreted by the gastrointestinal tract, play a crucial role in maintaining blood glucose homeostasis. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulin-releasing peptide (GIP) are two major incretin hormones that increase glucose-dependent insulin secretion to exert a glucose-lowering effect. Glucagon, a hormone secreted by pancreatic α-cells, acts on the liver under stressful conditions such as cold and hunger, breaking down glycogen in the liver and raising blood glucose. In addition to its blood glucose-raising effects, glucagon also promotes lipolysis, fat oxidation, and fever.

[0003] Triple agonists that act simultaneously on the GLP-1, GIP, and glucagon receptors can simultaneously exert the activities of GLP-1, GIP, and glucagon. GLP-1 can lower blood sugar and suppress appetite; glucagon can break down fat and reduce weight, but its blood sugar-raising effects can be offset by the glucose-lowering activity of GLP-1; GIP primarily stimulates insulin secretion. The three activities of triple agonists of the GLP-1, GIP, and glucagon receptors work together to form a feedback mechanism based on blood sugar levels, achieving both blood sugar control and fat breakdown and weight reduction. For the treatment of diabetes and obesity, triple agonists of the GLP-1 / GIP / glucagon receptors offer significant advantages over single GLP-1 analogs and dual agonists of the GLP-1 / GIP receptors. By adjusting the fatty acid side chain structure of the agonist, single-target, dual-target or triple-target agonists of receptors such as GLP-1 / GIP / glucagon can be developed, which will have greater potential in the development of drugs to treat metabolic syndromes such as type 2 diabetes, obesity, non-alcoholic steatohepatitis, etc.

[0004] Patent document CN115806593B discloses a fatty acid chain-modified dual agonist of glucose-dependent insulin-releasing peptide and glucagon-like peptide-1 receptors, which is modified by introducing side chains of different lengths. It has the effects of lowering blood sugar and controlling weight, and can be used as an effective raw material for the preparation of a drug for treating or preventing related metabolic diseases such as diabetes, obesity and non-alcoholic steatohepatitis. The results of the mouse weight loss experiment in Example 12 thereof were compared with those of the present application. It was found that when the dosage was the same but the dosing frequency was much higher than that of the present application, the polypeptide compound of the patent document was less effective in reducing the weight of DIO mice than that of the present application. Specifically, taking the 10th day after administration as an example, the weight of mice administered with JK-1246R-007 in the present application decreased by about 37% (100%-63%=37%), while the weight of mice administered with the synthetic polypeptide compound in the patent document decreased by up to about 32% (13 / 40×100%=32%).

[0005] Patent document WO2013127779A1 discloses a glucagon-like peptide 1, which is a GLP-1 prodrug, and its side chain structure can be: However, the role of this side chain structure is only to prolong the half-life of the drug, rather than enhancing the hypoglycemic and weight-reducing effects of the present application.

[0006] In view of the defects in the above-mentioned existing technologies, there is an urgent need to develop new fatty acid side chains to modify GLP-1 / GIP / glucagon receptor agonists, thereby improving the efficacy of receptor agonists in lowering blood sugar and reducing weight. Summary of the Invention

[0007] The first aspect of the present invention provides a fatty acid chain having a structure shown in formula (I):

[0008]

[0009] Where R1 is C 1-12 Straight chain / branched chain alkyl or

[0010] R2 is a free single bond or c is an integer selected from 1-30 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30);

[0011] a and b are each independently selected from an integer of 1-30 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30).

[0012] Preferably, a is an integer selected from 1-20, more preferably, a is 17.

[0013] Preferably, b is an integer selected from 1-20, more preferably, b is 19.

[0014] Preferably, c is an integer selected from 1-10, more preferably, c is an integer selected from 1-5, and most preferably, c is 2.

[0015] In one embodiment of the present invention, R1 is

[0016] In one embodiment of the present invention, R2 is a free single bond.

[0017] In one embodiment of the present invention, R2 is In one embodiment of the present invention, the fatty acid chain has a structure shown in formula (II):

[0018]

[0019] In one embodiment of the present invention, the fatty acid chain has a structure shown in formula (II-1):

[0020]

[0021] In one embodiment of the present invention, the fatty acid chain has a structure shown in formula (II-2):

[0022]

[0023] In one embodiment of the present invention, the fatty acid chain has a structure shown in formula (III):

[0024] In one embodiment of the present invention, the fatty acid chain has a structure shown in formula (III-1):

[0025]

[0026]

[0027] In one embodiment of the present invention, the fatty acid chain has a structure shown in formula (III-2):

[0028]

[0029] The second aspect of the present invention provides a receptor agonist, wherein the receptor agonist is modified by the fatty acid chain as described in the first aspect.

[0030] Furthermore, the amino acid sequence of the receptor agonist is shown in SEQ ID NO: 1:

[0031] Tyr-{Aib}-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-{Aib}-Leu-Asp-Lys-Ile-Ala-Gln-Ly s-Ala-Phe-Val-Gln-Trp-Leu-Ile-Ala-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

[0032] Furthermore, the lysine at position 20 of the receptor agonist is connected to the fatty acid chain as described in the first aspect.

[0033] The third aspect of the present invention provides a use of the fatty acid chain described in the first aspect in modifying a receptor agonist.

[0034] Furthermore, the receptor agonist is selected from a single receptor agonist, a dual receptor agonist or a triple receptor agonist.

[0035] In one embodiment of the present invention, the receptor is selected from one or a combination of two or more of GLP-1, GIP and glucagon.

[0036] The fourth aspect of the present invention provides a use of the receptor agonist as described in the second aspect.

[0037] Furthermore, the application is one or more of the following:

[0038] (1) Application in the preparation of products for preventing and treating diabetes;

[0039] (2) Application in the preparation of products for improving glucose tolerance;

[0040] (3) Application in the preparation of products for lowering blood sugar;

[0041] (4) Use in the preparation of products for controlling appetite, food intake or calorie intake;

[0042] (5) Application in the preparation of products that increase energy consumption;

[0043] (6) Use in the preparation of products for preventing weight gain;

[0044] (7) Use in the preparation of products that promote weight loss;

[0045] (8) Use in the preparation of products for reducing excess body weight;

[0046] (9) Application in the preparation of products for treating obesity.

[0047] Furthermore, the product also includes a pharmaceutically acceptable carrier, diluent or excipient.

[0048] Beneficial effects:

[0049] The present invention improves the carbon chain length, functional group types, etc. of fatty acid chains and uses them to modify receptor agonists, significantly improving the therapeutic effects of receptor agonists in lowering blood sugar and reducing weight. The effects are comparable to or even better than those of positive drugs. The fatty acid chains of the present invention and the modified receptor agonists thereof can lower blood sugar levels and improve glucose tolerance; at the same time, they have the effects of controlling appetite, food intake and calorie intake, increasing energy expenditure, preventing weight gain, promoting weight loss and reducing overweight. In addition, the fatty acid chains of the present invention and the modified receptor agonists thereof have a long half-life and can effectively prolong the duration of drug action in the body.

[0050] The term C in the present invention 1-12 Straight chain / branched chain alkyl, including methyl, ethyl, C3 straight chain / branched chain alkyl, C4 straight chain / branched chain alkyl, C5 straight chain / branched chain alkyl, C6 straight chain / branched chain alkyl, C7 straight chain / branched chain alkyl, C8 straight chain / branched chain alkyl, C9 straight chain / branched chain alkyl, C 10 Straight chain / branched chain alkyl, C 11 Straight chain / branched chain alkyl, C 12 Straight chain / branched chain alkyl. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The non-fasting blood glucose levels of db / db mice in each group at different time points within 6 hours after drug administration.

[0052] Figure 2 The blood glucose AUC of db / db mice in each group 6 hours after drug administration.

[0053] Figure 3 The body weight changes of C57BL / 6N mice at different time points within 23 days of continuous administration of 30 nmol / kg.

[0054] Figure 4 The blood glucose AUC was observed in C57BL / 6N mice after continuous administration of 30 nmol / kg for 23 days.

[0055] Figure 5This is the NMR spectrum of the side chain compound 1.

[0056] Figure 6 This is the NMR spectrum of the side chain compound 2.

[0057] Figure 7 This is the NMR spectrum of the side chain compound 3.

[0058] Figure 8 This is the NMR spectrum of the side chain compound 4.

[0059] Figure 9 Shown are the glucose tolerance of C57BL / 6J mice in each group at different time points within 24 to 26 hours after drug administration.

[0060] Figure 10 The blood glucose AUC of C57BL / 6J mice in each group 24 to 26 hours after drug administration. DETAILED DESCRIPTION

[0061] In order to enable a clearer understanding of the technical content of the present invention, the following embodiments are given in detail to provide a clear and complete description of the technical solutions of the present invention. The purpose is only to better understand the content of the present invention but not to limit the scope of protection of the present invention. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0062] The term "DIEA" is N,N-diisopropylethylamine;

[0063] The term "TSTU" is 2-succinimidyl-1,1,3,3-tetramethyluronium tetrafluoroborate;

[0064] The term "DCM" is dichloromethane;

[0065] The term "TEA" is triethylamine;

[0066] The term "MTBE" is methyl tert-butyl ether;

[0067] The term "NMP" is N-methylpyrrolidone.

[0068] Example 1 Synthesis of fatty acid side chains

[0069] 1. Synthesis of side chain compound 1:

[0070]

[0071] Dissolve 1.0g of mono-tert-butyl eicosandioate in 20ml of dichloromethane, add 0.46ml of DIEA, then add 0.83g of TSTU, stir for 3 hours, add 0.42ml of TEA, then add 0.56g of 1-tert-butyl L-glutamate, and stir overnight. After the reaction is complete, wash twice with 20ml of 0.2N HCl, dry the DCM phase, and filter. Add 0.46ml of DIEA to the filtrate, then add 0.83g of TSTU, stir for 3 hours, then add 0.42ml of TEA and 0.92g of NH2-PEG5-CM, stir overnight. After the reaction is complete, wash twice with 20ml of 0.2N HCl, dry the dichloromethane phase, filter, and concentrate to obtain the crude product. The crude product was purified by column chromatography to obtain compound 1tBuO-ICO-Glu(PEG5-OH)-OtBu (1.1g, white solid) with a yield of 51%. The NMR spectrum is shown in Figure 2. Figure 5 .

[0072] MSm / z(ESI):861.6[M+1]

[0073] 2. Synthesis of side chain compound 2

[0074]

[0075] Dissolve 1.0g of mono-tert-butyl eicosandioate in 20ml of dichloromethane, add 0.46ml of DIEA, then add 0.83g of TSTU, stir for 3 hours, add 0.42ml of TEA, then add 0.56g of 1-tert-butyl L-glutamate, and stir overnight. After the reaction is complete, wash twice with 20ml of 0.2N HCl, dry the DCM phase, and filter. Add 0.46ml of DIEA to the filtrate, then add 0.83g of TSTU, stir for 3 hours, then add 0.42ml of TEA and 1.07g of NH2-PEG3-PEG2-CM, stir overnight. After the reaction is complete, wash twice with 20ml of 0.2N HCl, dry the dichloromethane phase, filter, and concentrate to obtain the crude product. The crude product was purified by column chromatography to obtain the compound 2tBuO-ICO-Glu(PEG3-PEG2-OH)-OtBu (1.0g, white solid) with a yield of 44%. The NMR spectrum is shown in Figure 4. Figure 6 .

[0076] MSm / z(ESI):918.6[M+1]

[0077] 3. Synthesis of side chain compound 3

[0078]

[0079] Dissolve 0.5g of mono-tert-butyl docosanoate in 10ml of dichloromethane, add 0.21ml of DIEA, then add 0.39g of TSTU, stir for 3 hours, add 0.2ml of TEA, then add 0.26g of 1-tert-butyl L-glutamate, and stir overnight. After the reaction is complete, wash twice with 10ml of 0.2N HCl, dry the DCM phase, and filter. Add 0.21ml of DIEA to the filtrate, then add 0.39g of TSTU, stir for 3 hours, then add 0.2ml of TEA and 0.5g of NH2-PEG3-PEG2-CM, stir overnight. After the reaction is complete, wash twice with 10ml of 0.2N HCl, dry the dichloromethane phase, filter, and concentrate to obtain the crude product. The crude product was purified by column chromatography to obtain compound 3tBuO-DOC-Glu(PEG3-PEG2-OH)-OtBu (0.32g, white solid) with a yield of 30%. The NMR spectrum is shown in Figure 2. Figure 7 .

[0080] MSm / z(ESI):946.7[M+1]

[0081] 4. Synthesis of side chain compound 4

[0082]

[0083] Dissolve 0.5g of eicosanoic acid in 10ml of dichloromethane, add 0.3ml of DIEA, then add 0.53g of TSTU, stir for 3 hours, add 0.27ml of TEA, then add 0.36g of 1-tert-butyl L-glutamate, and stir overnight. After the reaction is complete, wash twice with 10ml of 0.2N HCl, dry the DCM phase, filter, add 0.3ml of DIEA to the filtrate, then add 0.53g of TSTU, stir for 3 hours, then add 0.27ml of TEA and 0.68g of NH2-PEG3-PEG2-CM, stir overnight, and after the reaction is complete, wash twice with 10ml of 0.2N HCl, dry the dichloromethane phase, filter, and concentrate to obtain the crude product. The crude product was purified by column chromatography to obtain compound 4ARA-Glu(PEG3-PEG2-OH)-OtBu (0.8g, white solid) with a yield of 60%. The NMR spectrum is shown in FIG. Figure 8 .

[0084] MSm / z(ESI):832.6[M+1]

[0085] Example 2 Synthesis of Compound JK1246R-003

[0086]

[0087] Dissolve 300 mg of the side chain compound 1 from Example 1 in acetonitrile and add 106 mg (3.0 eq) of TEA. Dissolve 100 mg (1.1 eq) of 3,5-dichloro-2-hydroxybenzenesulfonyl chloride in tetrahydrofuran and add dropwise to the reaction system. Stir at room temperature overnight.

[0088] After the reaction was complete, the solvent was removed by rotary evaporation, and MTBE was added with stirring to precipitate a white solid. The white solid was removed by suction filtration to obtain a clear filtrate. The filtrate was then rotary evaporated to remove the solvent to obtain a yellow oil. This was used directly in the next reaction.

[0089]

[0090] Dissolve the oil in 10V formic acid and stir at room temperature for approximately 20 hours. After the reaction is complete, remove the reaction mixture by rotary evaporation to obtain an oily product, which is used directly in the coupling reaction.

[0091] To 100 mg of telpotide, add 3 mL of water and adjust the pH to 10 with TEA. Dissolve 28 mg (1.2 eq, 0.0295 mmol) of the active ester of side chain compound 1 in 0.3 mL of NMP and add dropwise to the alkaline aqueous solution of the peptide. During the reaction, maintain the pH between 11.0 and 12.0 with 1 M NaOH. Allow to react for 2 h.

[0092] After the reaction was complete, acetic acid was added dropwise to quench the reaction, and 3 mL of acetonitrile was added to clarify the system. Purification was performed using reverse-phase high-pressure preparative liquid chromatography, and high-purity fractions were collected. The fractions were desalted using a gel column and lyophilized to obtain a white powdery solid.

[0093]

[0094] Example 3 Synthesis of Compound JK1246R-007

[0095]

[0096] Dissolve 200 mg of the side chain compound 3 from Example 1 in acetonitrile and add 64 mg (3.0 eq) of TEA. Dissolve 60 mg (1.1 eq) of 3,5-dichloro-2-hydroxybenzenesulfonyl chloride in tetrahydrofuran and add dropwise to the reaction system. Stir at room temperature overnight.

[0097] After the reaction was complete, the solvent was removed by rotary evaporation, and MTBE was added with stirring to precipitate a white solid. The white solid was removed by suction filtration to obtain a clear filtrate. The filtrate was then rotary evaporated to remove the solvent to obtain a yellow oil. This was used directly in the next reaction.

[0098]

[0099] Dissolve the oil in 10V formic acid and stir at room temperature for approximately 20 hours. After the reaction is complete, remove the reaction mixture by rotary evaporation to obtain an oily product, which is used directly in the coupling reaction.

[0100] To 100 mg of telpotide, add 3 mL of water and adjust the pH to 10 with TEA. Dissolve 32 mg (1.2 eq, 0.0295 mmol) of the active ester of side chain compound 3 in 0.3 mL of NMP and add dropwise to the alkaline aqueous solution of the peptide. During the reaction, maintain the pH between 11.0 and 12.0 with 1 M NaOH. Allow to react for 2 h.

[0101] After the reaction was complete, acetic acid was added dropwise to quench the reaction, and 3 mL of acetonitrile was added to clarify the system. Purification was performed using reverse-phase high-pressure preparative liquid chromatography to collect high-purity fractions containing the product of lysine 16 substitution in the tepol peptide chain. Each fraction was desalted using a gel column and lyophilized to obtain a white powdery solid.

[0102]

[0103] Comparative Example 1 Synthesis of Compound JK1246R-002

[0104]

[0105] Dissolve 300 mg of the side chain compound 2 from Example 1 in acetonitrile and add 100 mg (3.0 eq) of TEA. Dissolve 98 mg (1.1 eq) of 3,5-dichloro-2-hydroxybenzenesulfonyl chloride in tetrahydrofuran and add dropwise to the reaction system. Stir at room temperature overnight.

[0106] After the reaction was complete, the solvent was removed by rotary evaporation, and MTBE was added with stirring to precipitate a white solid. The white solid was removed by suction filtration to obtain a clear filtrate. The filtrate was then rotary evaporated to remove the solvent to obtain a yellow oil. This was used directly in the next reaction.

[0107]

[0108] Dissolve the oil in 10V formic acid and stir at room temperature for approximately 20 hours. After the reaction is complete, remove the reaction mixture by rotary evaporation to obtain an oily product, which is used directly in the coupling reaction.

[0109] To 100 mg of telpotide, add 3 mL of water and adjust the pH to 10 with TEA. Dissolve 50 mg (2.0 eq, 0.0492 mmol) of the active ester of side chain compound 2 in 0.3 mL of NMP and add dropwise to the alkaline aqueous solution of the peptide. During the reaction, maintain the pH between 11.0 and 12.0 with 1 M NaOH. Allow to react for 2 h.

[0110] After the reaction was complete, acetic acid was added dropwise to quench the reaction, and 3 mL of acetonitrile was added to clarify the system. Purification was performed using reverse-phase high-pressure preparative liquid chromatography, and high-purity fractions were collected. The fractions were desalted using a gel column and lyophilized to obtain a white powdery solid.

[0111]

[0112] Comparative Example 2 Synthesis of Compound JK1246R-004

[0113]

[0114] Dissolve 300 mg of the side chain compound 4 from Example 1 in acetonitrile and add 110 mg (3.0 eq) of TEA. Dissolve 100 mg (1.1 eq) of 3,5-dichloro-2-hydroxybenzenesulfonyl chloride in tetrahydrofuran and add dropwise to the reaction system. Stir at room temperature overnight.

[0115] After the reaction was complete, the solvent was removed by rotary evaporation, and MTBE was added with stirring to precipitate a white solid. The white solid was removed by suction filtration to obtain a clear filtrate. The filtrate was then rotary evaporated to remove the solvent to obtain a yellow oil. This was used directly in the next reaction.

[0116]

[0117] Dissolve the oil in 10V formic acid and stir at room temperature for approximately 20 hours. After the reaction is complete, remove the reaction mixture by rotary evaporation to obtain an oily product, which is used directly in the coupling reaction.

[0118] To 100 mg of telpotide, add 3 mL of water and adjust the pH to 10 with TEA. Dissolve 28 mg (1.2 eq, 0.0295 mmol) of the active ester of side chain compound 4 in 0.3 mL of NMP and add dropwise to the alkaline aqueous solution of the peptide. During the reaction, maintain the pH between 11.0 and 12.0 with 1 M NaOH. Allow to react for 2 h.

[0119] After the reaction was complete, acetic acid was added dropwise to quench the reaction, and 3 mL of acetonitrile was added to clarify the system. Purification was performed using reverse-phase high-pressure preparative liquid chromatography, and high-purity fractions containing the lysine 20 substitution product in the tepol peptide chain were collected. Each fraction was desalted using a gel column and lyophilized to obtain a white powdery solid.

[0120]

[0121] Comparative Example 3 Synthesis of Compound JK1246R-005

[0122]

[0123] Dissolve 300 mg of the side chain compound 4 from Example 1 in acetonitrile and add 110 mg (3.0 eq) of TEA. Dissolve 100 mg (1.1 eq) of 3,5-dichloro-2-hydroxybenzenesulfonyl chloride in tetrahydrofuran and add dropwise to the reaction system. Stir at room temperature overnight.

[0124] After the reaction was complete, the solvent was removed by rotary evaporation, and MTBE was added with stirring to precipitate a white solid. The white solid was removed by suction filtration to obtain a clear filtrate. The filtrate was then rotary evaporated to remove the solvent to obtain a yellow oil. This was used directly in the next reaction.

[0125]

[0126] Dissolve the oil in 10V formic acid and stir at room temperature for approximately 20 hours. After the reaction is complete, remove the reaction mixture by rotary evaporation to obtain an oily product, which is used directly in the coupling reaction.

[0127] To 100 mg of telpotide, add 3 mL of water and adjust the pH to 10 with TEA. Dissolve 28 mg (1.2 eq, 0.0295 mmol) of the active ester of side chain compound 4 in 0.3 mL of NMP and add dropwise to the alkaline aqueous solution of the peptide. During the reaction, maintain the pH between 11.0 and 12.0 with 1 M NaOH. Allow to react for 2 h.

[0128] After the reaction was complete, acetic acid was added dropwise to quench the reaction, and 3 mL of acetonitrile was added to clarify the system. Purification was performed using reverse-phase high-pressure preparative liquid chromatography, and high-purity fractions containing the lysine 16 substitution product in the tepol peptide chain were collected. Each fraction was desalted using a gel column and lyophilized to obtain a white powdery solid.

[0129]

[0130] Comparative Example 4 Synthesis of Compound JK1246R-006

[0131]

[0132] Dissolve 200 mg of side chain compound 3 in acetonitrile and add 64 mg (3.0 eq) of TEA. Dissolve 60 mg (1.1 eq) of 3,5-dichloro-2-hydroxybenzenesulfonyl chloride in tetrahydrofuran and add dropwise to the reaction system. Stir at room temperature overnight.

[0133] After the reaction was complete, the solvent was removed by rotary evaporation, and MTBE was added with stirring to precipitate a white solid. The white solid was removed by suction filtration to obtain a clear filtrate. The filtrate was then rotary evaporated to remove the solvent to obtain a yellow oil. This was used directly in the next reaction.

[0134]

[0135] Dissolve the oil from the previous step in 10V formic acid and stir at room temperature for approximately 20 hours. After the reaction is complete, remove the reaction solution by rotary evaporation to obtain an oil, which is used directly in the coupling reaction. Add 3mL of water to 100mg of telpotide and adjust the pH to 10 with TEA. Dissolve 32mg (1.2eq, 0.0295mmol) of the active ester of side chain compound 3 in 0.3mL of NMP and add dropwise to the alkaline aqueous solution of the peptide. During the reaction, adjust the pH of the system to 11.0-12.0 with 1M NaOH. Allow to react for 2 hours.

[0136] After the reaction was complete, acetic acid was added dropwise to quench the reaction, and 3 mL of acetonitrile was added to clarify the system. Purification was performed using reverse-phase high-pressure preparative liquid chromatography, and high-purity fractions containing the lysine 20 substitution product in the tepol peptide chain were collected. Each fraction was desalted using a gel column and lyophilized to obtain a white powdery solid.

[0137]

[0138] Example 4 Evaluation of the hypoglycemic effect of JK1246R-002, JK1246R-003, JK1246R-004, JK1246R-005, JK1246R-006 and JK1246R-007

[0139] 1. Intraperitoneal glucose tolerance test (iPTGG) in normal mice

[0140] 1. Experimental Design

[0141] Each group contained 6 male C57BL / 6J mice, which were subsequently given the test article. The experimental design was as follows:

[0142]

[0143] 2. Grouping

[0144] After 3 days of adaptive feeding, the mice were weighed and randomly divided into groups according to their body weight and blood glucose levels, with 6 mice in each group.

[0145] 3. Dosage method

[0146] All mice in the dosing groups were dosed 24 h in advance on the same day. The dosage was calculated based on the most recent weight of the animals. The drugs were administered by subcutaneous injection, with a single dose. The animals in each group were randomly dosed in alternating order.

[0147] 4. Intraperitoneal glucose tolerance test

[0148] After administration, mice were placed in metabolic cages and fasted for 12 h. Blood was collected from the tail 1 h before glucose administration (recorded as 0-min blood glucose). Glucose (2 g / kg) was injected intraperitoneally 15 min later, and blood glucose levels were measured 15, 30, 45, 60, and 120 min after glucose administration. Animals remained fasted during the experiment to prevent interference with food intake.

[0149] 5. Experimental results

[0150] like Figure 9 and Figure 10 As shown, the blood glucose of wild-type mice in the vehicle group rose rapidly 15 minutes after intraperitoneal injection of glucose and then dropped to near the baseline level at 120 minutes.

[0151] Compared with the vehicle group, the tirzepatide group still showed significant improvement in glucose tolerance 24 to 26 hours after a single subcutaneous injection of 30 nmol / kg into wild-type mice (p < 0.05).

[0152] Compared with the vehicle group, the six compounds JK-1246R-(002-007) had significant glucose tolerance improving activity within 24-26 hours after a single subcutaneous injection of 30 nmol / kg into wild-type mice (p < 0.05).

[0153] Compared with the tirzepatide group, 24 to 26 hours after administration, the activity of JK-1246R-002 in improving glucose tolerance was comparable to that of tirzepatide, with no significant difference;

[0154] Compared with the tirzepatide group, JK-1246R-003 and JK-1246R-004 showed slightly weaker glucose tolerance-improving activity than tirzepatide 24 to 26 hours after administration;

[0155] Compared with the tirzepatide group, 24 to 26 hours after administration, the three compounds JK-1246R-005, JK-1246R-006 and JK-1246R-007 were all superior to tirzepatide in improving glucose tolerance, with statistically significant differences.

[0156] 2. Evaluation of hypoglycemic effects in db / db mice

[0157] 1. Experimental design

[0158] Each group contained 8 male db / db mice, which were subsequently given the test article. The experimental design was as follows:

[0159]

[0160]

[0161] 2. Experimental Grouping

[0162] The mice were adaptively fed for 4 days and randomly divided into 5 groups according to body weight and pre-drug blood glucose, with 8 mice in each group.

[0163] 3. Dosage method

[0164] On the day of dosing, the dose was calculated based on the animal's most recent weight and administered subcutaneously (simulating the intended clinical route of administration, with the administration site as consistent as possible). Dosing was a single dose. Subcutaneous administration of the animal was performed according to the facility's standard operating procedures.

[0165] 4. Blood glucose monitoring

[0166] Free blood glucose (non-fasting blood glucose) was measured at the corresponding time points according to the group table. The animals were free to eat and drink during the experiment.

[0167] 5. Data Analysis

[0168] All data will be entered into an Excel document and expressed as "mean ± standard error" and converted to a percentage of pre-drug blood glucose. Statistical analysis will be performed using GraphPad Prism 8 (one-way ANOVA, Dunnett's method for multiple comparisons). A P value of less than 0.05 was considered significant.

[0169] 6. Experimental Results

[0170] like Figure 1 and 2 As shown, the non-fasting blood glucose of db / db mice in the vehicle group had no statistical difference at all time points within 6 hours after drug administration compared with that before drug administration, and was relatively stable;

[0171] Compared with the vehicle group at the same time points after administration, the non-fasting blood glucose and corresponding AUC of db / db mice were reduced at 1, 3, and 6 hours after a single subcutaneous injection of 30 nmol / kg in the tirzepatide group (p < 0.05);

[0172] Compared with the vehicle group at the same time points, the six compounds JK-1246R-(002-007) at a single dose of 30 nmol / kg were injected subcutaneously into db / db mice at 1, 3, and 6 hours after non-fasting blood glucose and the corresponding AUC decreased (p < 0.05);

[0173] Compared with the tirzepatide group at the same time point after administration, the non-fasting blood glucose and corresponding AUC of db / db mice 6 hours after a single subcutaneous injection of 30 nmol / kg in the JK-1246R-003 (Example 2) and JK-1246R-007 (Example 3) groups decreased (p < 0.05), indicating that the hypoglycemic effects of JK-1246R-003 and JK-1246R-007 of the present invention are superior to those of the positive drug tirzepatide. Compared with the tirzepatide group at the same time point after administration, the non-fasting blood glucose and corresponding AUC of db / db mice 6 hours after a single subcutaneous injection of 30 nmol / kg in the JK-1246R-002 (Comparative Example 1) and JK-1246R-006 (Comparative Example 4) groups decreased, but there was no significant difference compared with the tirzepatide group.

[0174] Compared with the tirzepatide group at the same time point after administration, the non-fasting blood glucose and corresponding AUC of the JK-1246R-004 (Comparative Example 2) and JK-1246R-005 (Comparative Example 3) groups in db / db mice 6 hours after a single subcutaneous injection were higher than those of the tirzepatide group, indicating that their hypoglycemic effects are weaker than those of tirzepatide.

[0175] Example 5 Evaluation of the Body Weight Loss Effect of JK1246R-003, JK1246R-006, and JK1246R-007

[0176] 1. Experimental Design

[0177] Each group contained 6 male C57BL / 6N mice, which were subsequently given the test article. The experimental design was as follows:

[0178]

[0179] 2. Modeling method

[0180] After one week of adaptive feeding with the basic diet, all animals were given a high-fat diet for modeling.

[0181] Guarantee measures: To reduce fighting between mice: add toys, observe whether the mice are injured every time the water is changed, and promptly raise the injured mice in separate cages; to reduce the high-fat feed being too soft, which makes it difficult for mice to grind off their teeth and thus affects their eating ability, add teeth grinding sticks.

[0182] 3. Grouping method

[0183] Before the first administration, the mice were randomly divided into 5 groups according to body weight, with 6 mice in each group.

[0184] 4. Dosage method

[0185] On the day of dosing, the dose was calculated based on the animal's most recent body weight and administered subcutaneously 30-90 minutes before the onset of the dark cycle. Dosing was repeated every three days until Day 20. Animals in each group were randomly assigned to alternate dosing schedules.

[0186] 5. Weigh yourself

[0187] All animals were weighed weekly during modeling. After dosing began, they were weighed daily. All animals were weighed when found dead, moribund, or subjected to unplanned euthanasia, as well as before planned euthanasia.

[0188] 6. Observe food intake

[0189] Monitor 24-h food intake once a week.

[0190] 7. Data analysis and test report

[0191] All data will be entered into an Excel file and expressed as "mean ± standard error". Statistical analysis was performed using GraphPad Prism 8 (one-way ANOVA, Dunnett's method for multiple comparisons). P values ​​less than 0.05 were considered significant.

[0192] 8. Experimental Results

[0193] like Figure 3 and Figure 4 As shown, compared with the vehicle group at the same time point after administration, the body weight and corresponding AUC of tirzepatide, JK-1246R-003, JK-1246R-006 and JK-1246R-007 were reduced after continuous administration at a dose of 30 nmol / kg for 23 days (p < 0.05).

[0194] Compared with the tirzepatide group at the same time point after administration, body weight and corresponding AUC of JK-1246R-003 and JK-1246R-006 after 23 days of continuous administration at a dose of 30 nmol / kg were not significantly different from those of the tirzepatide group. This suggests that JK-1246R-003 and JK-1246R-006 are as effective at reducing body weight as tirzepatide. Body weight and corresponding AUC of JK-1246R-007 after 23 days of continuous administration at a dose of 30 nmol / kg were lower than those of the tirzepatide group (p < 0.05), indicating that JK-1246R-007 is more effective than tirzepatide in reducing body weight.

Claims

1. A fatty acid chain having the structure shown in formula (I): in, R1 is C 1-12 Straight chain / branched chain alkyl or R2 is a free single bond or c is an integer selected from 1-30; a and b are each independently selected from an integer of 1-30.

2. The fatty acid chain according to claim 1, wherein Said a is an integer selected from 1-20, preferably, a is 17.

3. The fatty acid chain according to claim 1, wherein Said b is an integer selected from 1-20, preferably, b is 19.

4. The fatty acid chain according to claim 1, wherein Said c is an integer selected from 1-10, preferably, c is an integer selected from 1-5, and more preferably, c is 2.

5. The fatty acid chain according to claim 1, wherein The R1 is 6. The fatty acid chain according to claim 1, wherein The R2 is a free single bond.

7. The fatty acid chain according to claim 1, wherein The R2 is 8. The fatty acid chain according to claim 1, wherein The fatty acid chain has the structure shown in formula (II): Preferably, the fatty acid chain has the structure shown in formula (II-1): More preferably, the fatty acid chain has a structure shown in formula (II-2):

9. The fatty acid chain according to claim 1, wherein The fatty acid chain has a structure shown in formula (III): Preferably, the fatty acid chain has a structure shown in formula (III-1): More preferably, the fatty acid chain has a structure shown in formula (III-2):

10. A receptor agonist, characterized in that The receptor agonist is modified by the fatty acid chain as claimed in claim 1; The fatty acid chain has a structure shown in formula (II-2) or formula (III-2): The amino acid sequence of the receptor agonist is shown in SEQ ID NO: 1: Tyr-{Aib}-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-{Aib}-Leu-Asp-Lys-Ile-Ala-Gln-Ly s-Ala-Phe-Val-Gln-Trp-Leu-Ile-Ala-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2.

11. Use of the fatty acid chain according to any one of claims 1 to 9 in modifying a receptor agonist.

12. A use of the receptor agonist according to claim 10, wherein the use is one or more of the following: (1) Application in the preparation of products for preventing and treating diabetes; (2) Application in the preparation of products for improving glucose tolerance; (3) Application in the preparation of products for lowering blood sugar; (4) Use in the preparation of products for controlling appetite, food intake or calorie intake; (5) Application in the preparation of products that increase energy consumption; (6) Use in the preparation of products for preventing weight gain; (7) Use in the preparation of products that promote weight loss; (8) Use in the preparation of products for reducing excess body weight; (9) Application in the preparation of products for treating obesity.

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