A fatty acid side-chain modified GLP-2-derived polypeptide and its application in the preparation of antiseptic drugs

Abstract

This invention discloses a GLP-2-derived polypeptide modified with a fatty acid side chain, or a pharmaceutically acceptable salt thereof, wherein the amino acid sequence of the GLP-2-derived polypeptide is shown in general formula (I). Wherein, X1 is A or K, and X2 is K or D; the ε-amino group in K is linked to a side chain modifying group R, wherein R is selected from γGlu-fatty acid or OEG-OEG-γGlu-fatty acid, the fatty acid being selected from C8-C18 fatty acids, and OEG being an 8-amino-3,6-dioxanoic acid linker; wherein, when R does not contain an OEG linker, the ε-amino group in K forms an amide bond with the α-carboxyl group of γGlu, and the α-amino group of γGlu forms an amide bond with the carboxyl group of the fatty acid; when R contains an OEG linker, the ε-amino group in K is sequentially linked to γGlu via two OEGs, with amide bonds forming between adjacent linker units, and the α-amino group of γGlu forms an amide bond with the carboxyl group of the fatty acid. This derived polypeptide has a novel structure, possesses GLP-2R agonist activity, and can be used to prepare drugs for the treatment of sepsis.

Description

Technical Field

[0001] This invention relates to a fatty acid side-chain modified GLP-2-derived polypeptide and its application in the preparation of antiseptic drugs, belonging to the field of polypeptide technology. Background Technology

[0002] Sepsis is a life-threatening organ dysfunction resulting from infection-induced host response dysregulation. Its pathological process involves excessive inflammation, immunosuppression, metabolic reprogramming, microcirculatory disturbances, intestinal barrier disruption, and multiple organ dysfunction. Current clinical treatment mainly relies on early anti-infection, infection source control, fluid resuscitation, hemodynamic support, and organ support. Specific drugs targeting the host response imbalance itself remain limited.

[0003] The gut is not only a major organ affected by sepsis but can also be a source of persistent and amplified inflammation. Disruption of the intestinal barrier can lead to increased intestinal permeability, bacterial and bacterial translocation, gut microbiota imbalance, and metabolic phenotype disturbances, thereby further exacerbating systemic inflammation and organ damage. Therefore, improving intestinal barrier function has potential value for drug development.

[0004] GLP-2 is an intestinal peptide hormone that promotes intestinal mucosal growth, maintains tight junctions, and improves intestinal barrier function. However, natural GLP-2 is easily degraded by dipeptidyl peptidase IV and has a short half-life. Summary of the Invention

[0005] Objective of the Invention: To address the aforementioned technical problems, this invention provides a GLP-2-derived polypeptide modified with a fatty acid side chain and its application in the preparation of antiseptic drugs. Based on the structure-activity relationship of GLP-2, this invention enhances stability through 2-position anti-enzymatic modification, C-terminal amidation, and fatty acid side chain modification, thereby forming a novel antiseptic candidate molecule.

[0006] Technical solution: To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a fatty acid side-chain modified GLP-2-derived polypeptide or a pharmaceutically acceptable salt thereof, the amino acid sequence of which is shown in the following general formula (I):

[0008] H2N-HAibDGSFSDEMNTILDNLX1ARDFINWLIOTKITX2-CONH2

[0009] (I)

[0010] Where X1 is A or K, and X2 is K or D;

[0011] The ε-amino group in K is connected to the side chain modification group R, wherein R is selected from γGlu-fatty acid or OEG-OEG-γGlu-fatty acid, wherein the fatty acid is selected from C8-C18 fatty acid, and OEG is an 8-amino-3,6-dioxanoic acid linking unit.

[0012] Wherein, when R does not contain an OEG linker, the ε-amino group in K forms an amide bond with the α-carboxyl group of γGlu, and the α-amino group of γGlu forms an amide bond with the carboxyl group of the fatty acid; when R contains an OEG linker, the ε-amino group in K is sequentially linked to γGlu via two OEGs, and amide bonds are formed between adjacent linker units, and the α-amino group of γGlu forms an amide bond with the carboxyl group of the fatty acid.

[0013] As a specific implementation scheme, X1 is A and X2 is K; or X1 is K and X2 is D.

[0014] As a specific implementation, the fatty acid is selected from C8 fatty acids, C12 fatty acids, or C18 fatty acids.

[0015] In this invention, OEG refers to the 8-amino-3,6-dioxanoic acid linker introduced by Fmoc-AEEA-OH, and OEG-OEG represents two OEG linkers connected in series. This invention uses γGlu to represent the glutamyl linker introduced by Fmoc-Glu-OtBu: its α-carboxyl group forms an amide bond with the ε-amino group of Lys or the amino group of the preceding OEG linker, and its α-amino group forms an amide bond with the carboxyl group of a fatty acid; its side-chain carboxyl group is a free carboxyl group in the final product. Preferably, C8, C12, and C18 fatty acids represent octanoic acid, dodecanoic acid, and octadecanoic acid residues, respectively.

[0016] Preferably, the GLP-2-derived polypeptide is selected from one of the following polypeptides:

[0017] Polypeptide I-1:

[0018] ;

[0019] Polypeptide I-2:

[0020] ;

[0021] Polypeptide I-3:

[0022] ;

[0023] Polypeptide I-4:

[0024] ;

[0025] Peptide I-5:

[0026] ;

[0027] Polypeptide I-6:

[0028] ;

[0029] Polypeptide I-7:

[0030] ;

[0031] Polypeptide I-8:

[0032] ;

[0033] Polypeptide I-9:

[0034] ;

[0035] Polypeptide I-10:

[0036] ;

[0037] Polypeptide I-11:

[0038] ;

[0039] Polypeptide I-12:

[0040] ;

[0041] Wherein, K is connected to a side-chain modifying group via an ε-amino group.

[0042] As a specific implementation, the salt is a salt formed by a GLP-2 derived polypeptide and one of the following compounds: acetic acid, salicylic acid, lauric acid, cinnamic acid, lactic acid, or succinic acid.

[0043] In a second aspect, the present invention provides a pharmaceutical composition comprising a therapeutically effective amount of at least one of the GLP-2-derived peptides or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier and / or excipients.

[0044] As a specific implementation, the dosage form of the composition is, as described in pharmaceutical science, a tablet, capsule, tincture, inhaler, spray, injection, film, patch, powder, granule, emulsion, or suppository.

[0045] Thirdly, the present invention provides the use of the GLP-2 derived polypeptide or a pharmaceutically acceptable salt thereof, and the pharmaceutical composition thereof, in the preparation of GLP-2 receptor agonists.

[0046] Fourthly, the present invention provides the use of the GLP-2 derived polypeptide or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition described in 7, in the preparation of medicaments for the prevention and / or treatment of sepsis.

[0047] Fifthly, the present invention provides the use of the GLP-2 derived polypeptide or a pharmaceutically acceptable salt thereof, and the pharmaceutical composition thereof, in the preparation of medicaments for the prevention, mitigation, and / or treatment of sepsis-like injury or intestinal barrier damage.

[0048] The drugs described in this invention can improve the survival rate and / or prolong the survival time of sepsis-like models, reduce sepsis-related intestinal permeability, alleviate intestinal barrier damage, and / or reduce amplified intestinal inflammation. They can also reduce the levels of one or more inflammatory factors among IL-1β, TNF-α, and IL-6.

[0049] Unless the context otherwise requires, “septicemia-like injury” as used in this article refers to decreased survival, systemic inflammatory response, increased intestinal permeability and related tissue damage in animal models induced by lipopolysaccharide; “intestinal barrier injury” refers to abnormalities in the integrity or permeability of the intestinal epithelial barrier; and “systemic inflammatory response” refers to elevated levels of one or more circulating inflammatory factors, including IL-1β, TNF-α and IL-6.

[0050] The method for synthesizing GLP-2-derived peptide compounds according to the present invention includes: elongating the peptide chain from the C-terminus to the N-terminus using the Fmoc solid-phase peptide synthesis method, and using Fmoc-Lys(Dde)-OH at the Lys site to be modified; after completing the main chain synthesis, selectively removing the Dde protecting group using a hydrazine hydrate / DMF system; for compounds without OEG linker units, sequentially coupling Fmoc-Glu-OtBu, removing the Fmoc protecting group, and coupling octanoic acid, dodecanoic acid, or octadecanoic acid; for compounds containing OEG-OEG linker units, sequentially coupling two Fmoc-AEEA-OH linker units, removing the corresponding Fmoc protecting group after each coupling, and then coupling Fmoc-Glu-OtBu, removing the Fmoc protecting group, and coupling octanoic acid, dodecanoic acid, or octadecanoic acid; subsequently, cleaving using a TFA / TIS / water / EDT cleavage system, followed by ether precipitation, reversed-phase high-performance liquid chromatography purification, and liquid chromatography-mass spectrometry confirmation.

[0051] This invention, based on the structure-activity relationship of GLP-2, introduces α-aminoisobutyric acid (Aib) at the 2-position to amidate the C-terminus, and introduces γGlu or OEG-OEG-γGlu linker units and fatty acids of different lengths through specific Lys side chains to improve peptide stability and construct a new antiseptic candidate molecule. The theoretical basis for this design is as follows: the 2-position of natural GLP-2 is the main recognition and cleavage site of dipeptidyl peptidase IV (DPP-IV). Introducing the non-natural amino acid Aib at the 2-position increases the steric hindrance of this site, reducing the likelihood of it being recognized and hydrolyzed by DPP-IV; C-terminal amidation reduces the terminal charge and decreases the likelihood of carboxypeptidase recognizing the C-terminus; the fatty acid side chain has the potential to undergo reversible hydrophobic interactions with serum albumin; the OEG linker unit increases the flexibility and hydrophilicity of the linker arm and reduces the steric interference of fatty acid modification on the receptor binding region.

[0052] Technical Effects: Compared with existing technologies, this invention provides a series of novel GLP-2-derived peptides modified with fatty acid side chains. In vitro cAMP receptor activity experiments show that these peptides possess GLP-2R agonist activity. Furthermore, experimental results also show that these peptide derivatives can significantly improve the survival rate of sepsis-like mice and reduce intestinal permeability and the levels of some inflammatory factors. Therefore, these GLP-2-derived peptides can be used to prepare drugs for the prevention, mitigation, and / or treatment of sepsis-like injury and its associated intestinal barrier damage and inflammatory responses. Attached Figure Description

[0053] Figure 1 The concentration-effect curves of peptides I-1 to I-6 on GLP-2R are shown.

[0054] Figure 2 The effect of peptides on the 5-day survival rate of LPS-induced sepsis-like mice.

[0055] Figure 3 To optimize the effect of peptides on intestinal permeability in LPS-induced sepsis-like mice.

[0056] Figure 4 To optimize the effect of peptides on serum IL-1β, TNF-α and IL-6 levels in LPS-induced sepsis-like mice. Detailed Implementation

[0057] The invention will be further illustrated below with specific examples.

[0058] Unless otherwise defined herein, the scientific and technical terms used in this application shall have the meanings commonly understood by one of ordinary skill in the art. Generally, the terms and methods used herein in connection with chemistry, biology, and pharmacology are well-known and commonly used in the art.

[0059] In addition, the abbreviations in the structural formula of this invention represent specific amino acids, and adjacent amino acids are connected by peptide bonds. The amino acids are abbreviated according to the IUPAC-IUB naming rules as follows:

[0060] Alanine (Ala, A); Arginine (Arg, R); Asparagine (Asn, N); Aspartic acid (Asp, D); Cysteine ​​(Cys, C); Glutamic acid (Glu, E); Glutamine (Gln, Q); Glycine (Gly, G); Histidine (His, H); Isoleucine (Ile, I); Leucine (Leu, L); Lysine (Lys, K); Methionine (Met, M); Phenylalanine (Phe, F); Proline (Pro, P); Serine (Ser, S); Threonine (Thr, T); Tryptophan (Trp, W); Tyrosine (Tyr, Y); Valine (Val, V).

[0061] In addition, unless otherwise specified, all amino acid residues in the polypeptide compounds of the present invention are preferably in the L configuration.

[0062] In addition to natural amino acids, α-aminoisobutyric acid (Aib) is also used in the sequence of this invention.

[0063] Additionally, the "-NH2" portion at the C-terminus of the sequence indicates an amide group (-CONH) at the C-terminus.

[0064] The present invention is illustrated by the following embodiments, but these embodiments are not intended to limit the rights of the present invention in any way.

[0065] Example 1: Synthesis of GLP-2 Derivative Peptides

[0066] Based on the GLP-2 sequence, this invention introduces Aib at position 2 to improve tolerance to DPP-IV degradation. γGlu or OEG-OEG-γGlu linker units are connected via Lys side chains at positions 18 or 33, and further linked with C8, C12, or C18 fatty acids to obtain I-1 to I-12 with different side chain lengths and linker arm combinations. Their specific structures are shown in the peptides I-1 to I-12 described above.

[0067] The specific synthesis process and identification of this series of polypeptides are as follows:

[0068] (1) Solid-phase synthesis and side chain modification

[0069] Fmoc-Rink Amide-MBHA resin was placed in a solid-phase synthesis tube, swollen with dichloromethane for 30 min, and washed with DMF. The Fmoc protecting groups were removed in stages using 20% ​​piperidine / DMF, followed by washing with DMF, and the free amino groups were detected using ninhydrin / phenol colorimetric assay. Amino acids were sequentially coupled to the target peptide chain from the C-terminus to the N-terminus. Approximately 4 molar equivalents of Fmoc-protected amino acids were used in each step, with HBTU / HOBt as the condensation system and DIPEA as the activating base, and coupling was performed in DMF for approximately 2 h.

[0070] Fmoc-Lys(Dde)-OH was used at the Lys18 or Lys33 modification sites. After the main chain synthesis was completed, the Dde protecting group was selectively removed using a 2% hydrazine hydrate / DMF system. For I-1 to I-3 and I-7 to I-9, Fmoc-Glu-OtBu was coupled first, and its Fmoc protecting group was removed before coupling with octanoic acid, dodecanoic acid, or octadecanoic acid, respectively. For I-4 to I-6 and I-10 to I-12, two Fmoc-AEEA-OH linking units were coupled sequentially, and the corresponding Fmoc protecting group was removed after each coupling. Then, Fmoc-Glu-OtBu was coupled, and its Fmoc protecting group was removed before coupling with the corresponding fatty acid, respectively.

[0071] After peptide chain and side chain synthesis, a lysis buffer with a TFA / TIS / water / EDT volume ratio of 94:1:2.5:2.5 was added, and the reaction was carried out at room temperature for about 3 hours. The resin was removed by filtration, and the lysis buffer was added to pre-cooled anhydrous diethyl ether to precipitate the crude peptide. After centrifugation and washing with diethyl ether, the peptide was dried.

[0072] (2) Purification and structural confirmation

[0073] The crude peptide was dissolved in 25% acetonitrile / water solution, sonicated, and centrifuged. The supernatant was filtered through a 0.22 μm filter membrane. Purification was performed using a C18 reversed-phase preparative column with mobile phase A of 0.1% TFA / water and mobile phase B of 0.1% TFA / acetonitrile at a flow rate of 5 mL / min and a detection wavelength of 214 nm. A gradient elution of 25%–75% B for 55 min was used. The target peak was collected, acetonitrile was removed, and the peptide was lyophilized. Purity was determined by analytical HPLC, and molecular weight was confirmed by LC-MS.

[0074] The structure, modification, and analytical data of the derived peptides are shown in the table below:

[0075]

[0076] Example 2: GLP-2R agonist activity of GLP-2 derived peptides

[0077] In this embodiment, the receptor agonist activity of the CHO cell line CHO-GLP-2R#, which stably expresses the human GLP-2 receptor, was evaluated. Cells were cultured at 37 °C, 5% CO2, and saturated humidity in F-12 complete medium containing 10% fetal bovine serum, with 8 μg / mL puromycin added to maintain stable expression selection pressure. Cell status was maintained through regular passages, and cell confluence was controlled to approximately 80% before the experiment.

[0078] During cell passage, the original culture medium was removed, adherent cells were washed with pre-cooled PBS, and 1 mL of pre-warmed (37 °C) non-enzymatic cell dissociation buffer was added. Cells were incubated at 37 °C for 2–3 min until detachment occurred. 5 mL of complete culture medium was added to terminate dissociation. Cells were gently pipetted to prepare a single-cell suspension and centrifuged at 1000 rpm for 5 min. Cells in the logarithmic growth phase were collected and counted.

[0079] Following the operating instructions of the LANCE Ultra cAMP assay kit, a fresh 1× assay buffer was prepared. This assay buffer consisted of Hank's balanced salt solution containing 5 mM HEPES, 0.1% bovine serum albumin, and 500 μM IBMX. Cells I-1 to I-6 and the native GLP-2 positive control were serially diluted with 1× stimulation buffer to prepare a 10-fold working solution. Cells were seeded at 9 μL / well in 384-well polystyrene white flat-bottom microplates, approximately 2000 cells per well. Then, 1 μL of the compound working solution was added to each well, and the mixture was centrifuged and incubated at 37 °C for 30 min.

[0080] After incubation, the detection reagents were diluted to the working concentration with detection buffer according to the kit instructions, added to each well, centrifuged, and incubated at room temperature in the dark for 1 h. Dual-wavelength detection was performed using a Pherastar FSX multi-mode microplate reader, with detection wavelengths set at 665 nm and 620 nm. The intracellular cAMP response was characterized by the 665 nm / 620 nm fluorescence ratio. EC50 was calculated using a four-parameter logistic equation to perform nonlinear regression on the concentration-response curves in GraphPad Prism 9.0 software. Each compound was tested in triplicate (n=3).

[0081]

[0082] The concentration-response curves of I-1 to I-6 on GLP-2R are as follows: Figure 1As shown, all compounds exhibit a receptor agonistic effect that increases with increasing concentration. The corresponding EC₅₀ results are shown in the table data: I-1 to I-6 all retain GLP-2R agonistic activity, wherein the EC₅₀ of I-6 is 0.15±0.24 nM, which has the strongest activity among the compounds in this group; I-7 to I-12 were not tested separately in this in vitro receptor assay.

[0083] Example 3 In vivo experiment of GLP-2 derived polypeptide

[0084] I. Effect on survival rate of LPS-induced sepsis-like mice

[0085] The animals used in this example are male C57BL / 6J mice aged 6-8 weeks and weighing about 25 g, which were purchased from Zhejiang Vital River Laboratory Animal Technology Co., Ltd., and the production license number of experimental animals is SCXK (Zhejiang) 2025-0007. After one week of adaptive feeding, the animals were grouped by random number table method according to body weight. Drug administration, LPS modeling and sample collection were performed by different experimenters, and the experimenters who detected the experimental indicators did not know the grouping information during detection. The sample size was determined based on the research group's preliminary experiment and similar LPS models, with 7 mice in each group. The pre-set exclusion criteria are: death before modeling, failed administration, obvious non-experiment-related trauma or failed sample collection. All animal experiments were implemented in accordance with the management and use requirements of experimental animals, and approved by the animal ethics committee of the institution where the experiments were conducted.

[0086] The test polypeptide is prepared according to the administration dose of 30 nmol / kg: place the calculated amount of the polypeptide in a centrifuge tube, first dissolve it with a small amount of 1,2-propanediol, then dilute it to the required volume with normal saline, sonicate until the solution is clear, and store it in aliquots at -20 °C; restore to room temperature before administration. LPS is prepared with normal saline immediately before use. Weigh the body weight of each mouse before administration, and calculate the actual administration volume according to the administration volume of 0.01 mL / g body weight.

[0087] Mice were randomly divided into normal control group (NC), LPS model group, semaglutide group, teduglutide group, dapiglutide group and each test polypeptide group of I-1 to I-12. On days -5, -4, -3, -2 and -1, each drug group was subcutaneously administered 30 nmol / kg of the corresponding drug, and the NC group and LPS model group were administered an equal volume of normal saline; on day 0, all groups except the NC group were intraperitoneally injected with 30 mg / kg LPS, and the NC group was injected with an equal volume of normal saline. Continuous observation was carried out for 5 days after LPS injection, and the death was recorded every 6 hours, while the activity status, hair and behavior were observed. Death was taken as the endpoint event, and mice that were still alive at the end of the observation period were treated as censored data.

[0088] Statistical analysis was performed using GraphPad Prism 9.0. Survival curves were plotted using the Kaplan-Meier method, and differences between groups were analyzed using the log-rank test (Mantel-Cox test). Multiple group comparisons were corrected using the Holm-Sidak method. Final survival rates for each group were expressed as the number of surviving individuals / total number and as a percentage. The area under the survival curve (AUC) was calculated using the trapezoidal method to help evaluate overall survival during the observation period. A p-value < 0.05 was considered statistically significant.

[0089]

[0090]

[0091] The 5-day survival curves for each group are as follows: Figure 2 As shown in the figure, compared with the LPS model group, the 5-day survival rate of groups I-1, I-5, and I-7 all increased to 42.86%, with group I-5 showing a relatively high AUC. In the figure, semaglutide, teduglutide, and dapiglutide correspond to semaglutide, teduglutide, and dapiglutide, respectively; the asterisk indicates P < 0.05 compared to the LPS model group.

[0092] II. Effects of I-5 on intestinal permeability

[0093] Another batch of 6-8 week old male C57BL / 6J mice meeting the above-mentioned source and quality control requirements were randomly divided into four groups: normal control (NC), LPS model group, semaglutide group, tiduglutide group, dapoxetine group, 30 nmol / kg I-5 group, and 100 nmol / kg I-5 group, with 7 mice in each group. On days -5, -4, -3, -2, and -1, the I-5 group was subcutaneously administered 30 nmol / kg or 100 nmol / kg I-5, respectively. The three control drug groups were subcutaneously administered the corresponding drug at 30 nmol / kg. The NC group and LPS model group were given an equal volume of physiological saline. On day 0, except for the NC group, all mice were intraperitoneally injected with 10 mg / kg LPS, while the NC group was injected with an equal volume of physiological saline.

[0094] Twenty-one hours after LPS injection, mice in each group were administered 500 mg / kg fluorescein isothiocyanate-glucan (FD4) by gavage, with the entire process conducted in the dark. Twenty-four hours after LPS injection, mice were sacrificed and ocular blood was collected. Blood samples were allowed to stand at 4 °C for 1–2 hours, then centrifuged at 4 °C and 3000 rpm for 15 min to collect serum. The fluorescence intensity of serum samples and FD4 standard solutions was measured using a SpectraMax M5 microplate reader with an excitation wavelength of 485 nm and an emission wavelength of 528 nm. Serum FD4 concentration was calculated based on the standard curve.

[0095] Data were analyzed using GraphPad Prism 9.0 and are expressed as mean ± standard deviation. One-way ANOVA was used for comparisons between groups, followed by Tukey's multiple comparison test; p < 0.05 was considered statistically significant, and "*" in the figure indicates p < 0.05 compared to the LPS model group. Results are as follows... Figure 3 As shown, compared with the LPS model group, the serum FD4 concentration in the I-5 intervention group was lower, suggesting that I-5 can improve LPS-induced increased intestinal permeability.

[0096] III. Effects of I-5 on inflammatory factors

[0097] Another batch of 6-8 week old male C57BL / 6J mice meeting the above-mentioned source and quality control requirements were randomly divided into a normal control group (NC), an LPS model group, a semaglutide group, a tiduglutide group, a dapoxetine group, and an I-5 group, with 7 mice in each group. On days -5, -4, -3, -2, and -1, the I-5 group and the three control drug groups were subcutaneously administered 30 nmol / kg of the corresponding drug, while the NC group and the LPS model group were administered an equal volume of physiological saline. On day 0, except for the NC group, all mice were intraperitoneally injected with 10 mg / kg LPS, while the NC group was injected with an equal volume of physiological saline.

[0098] Mice were sacrificed 24 h after LPS injection, and ocular blood was collected. Blood samples were allowed to stand at 4 °C for 1–2 h, then centrifuged at 4 °C and 3000 rpm for 15 min to collect serum. Serum concentrations of IL-1β, TNF-α, and IL-6 were measured according to the respective ELISA kit instructions. Reproduced wells were set for each sample and standard as required by the kit, and the concentrations of each inflammatory factor were calculated based on the standard curve.

[0099] Data were analyzed using GraphPad Prism 9.0 and are expressed as mean ± standard deviation. One-way ANOVA was used for comparisons between groups, followed by Tukey's multiple comparison test; p < 0.05 was considered statistically significant. Results are as follows: Figure 4 As shown, compared with the LPS model group, I-5 can reduce serum IL-1β, TNF-α and IL-6 levels, with the improvement on TNF-α and IL-6 reaching statistical significance, suggesting that I-5 has an inflammatory regulatory effect.

[0100] In summary, peptides I-1, I-5, and I-7 exhibit survival protection effects, with I-5 showing potential for both improved intestinal permeability and inflammation regulation, making it a preferred candidate lead compound for the development of subsequent antiseptic drugs.

[0101] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A fatty acid side-chain modified GLP-2 derived polypeptide or a pharmaceutically acceptable salt thereof, characterized in that, The amino acid sequence of the GLP-2 derived polypeptide is shown in the following general formula (I): H2N-HAibDGSFSDEMNTILDNLX1ARDFINWLIOTKITX2-CONH2 （I） Where X1 is A or K, and X2 is K or D; The ε-amino group in K is connected to the side chain modification group R, wherein R is selected from γGlu-fatty acid or OEG-OEG-γGlu-fatty acid, wherein the fatty acid is selected from C8-C18 fatty acid, and OEG is an 8-amino-3,6-dioxanoic acid linking unit. Wherein, when R does not contain an OEG linker, the ε-amino group in K forms an amide bond with the α-carboxyl group of γGlu, and the α-amino group of γGlu forms an amide bond with the carboxyl group of the fatty acid; when R contains an OEG linker, the ε-amino group in K is sequentially linked to γGlu via two OEGs, and amide bonds are formed between adjacent linker units, and the α-amino group of γGlu forms an amide bond with the carboxyl group of the fatty acid.

2. The fatty acid side-chain modified GLP-2 derived polypeptide or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that, X1 is A and X2 is K; or X1 is K and X2 is D.

3. The fatty acid side-chain modified GLP-2 derived polypeptide or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that, The fatty acid is selected from C8 fatty acids, C12 fatty acids, or C18 fatty acids.

4. The fatty acid side-chain modified GLP-2 derived polypeptide or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that, The GLP-2-derived polypeptide is selected from one of the following polypeptides: Polypeptide I-1: ； Polypeptide I-2: ； Polypeptide I-3: ； Polypeptide I-4: ； Peptide I-5: ； Polypeptide I-6: ； Polypeptide I-7: ； Polypeptide I-8: ； Polypeptide I-9: ； Polypeptide I-10: ； Polypeptide I-11: ； Polypeptide I-12: ； Wherein, K is connected to a side-chain modifying group via an ε-amino group.

5. The fatty acid side-chain modified GLP-2 derived polypeptide or a pharmaceutically acceptable salt thereof according to claim 1, characterized in that, The salt is a salt formed by a GLP-2 derived polypeptide and one of the following compounds: acetic acid, salicylic acid, lauric acid, cinnamic acid, lactic acid, or succinic acid.

6. A pharmaceutical composition comprising a therapeutically effective amount of at least one GLP-2-derived polypeptide as described in any one of claims 1-5 or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier and / or excipient.

7. The composition according to claim 6, characterized in that, The dosage form of the composition is, as described in pharmaceutical science, a tablet, capsule, tincture, inhaler, spray, injection, film, patch, powder, granule, emulsion, or suppository.

8. The use of the GLP-2 derived polypeptide of any one of claims 1-5 or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claim 6 or 7, in the preparation of a GLP-2 receptor agonist.

9. The use of the GLP-2 derived polypeptide of any one of claims 1-5 or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claim 6 or 7, in the preparation of a medicament for the prevention and / or treatment of sepsis.

10. The use of the GLP-2 derived polypeptide of any one of claims 1-5 or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claim 6 or 7, in the preparation of a medicament for the prevention, mitigation, and / or treatment of sepsis-related damage.

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