Novel synthesis process of Urantide polypeptide

Abstract

The invention relates to the technical field of medicine and biology, and discloses a novel synthesis process of Urantide polypeptide, which discovers that specific impurity products always exist in mass spectrum identification of end products through multiple times of synthesis according to conventional methods and means, and through comparison, the part of impurities are substances with fragment sequence 1, and the content of the impurities in the product is higher than that in the prior art. Theoretically, impurity products are caused by polypeptide sequence breakage and existence of specific inherent impurities, a chemical fragment method is adopted in the scheme mentioned in the invention, reaction positions where polypeptide is prone to breakage are skipped, substances without fragment breakage before oxidation can be obtained, the product yield is greatly increased, the purification difficulty is reduced, and the method is suitable for industrial production. The unique Dmso / DMF oxidation condition is adopted, the condition oxidation effect is good, the oxidation process is stable, and the final product does not have other obvious impurities.

Description

Technical Field

[0001] The present invention relates to the fields of medicine and biotechnology, and specifically to a novel synthesis process of Urantide polypeptide. Background Art

[0002] Urantide: Asp-{Pen}-Phe-{d-Trp}-{Orn}-Tyr-Cys-Val (Disulfide bridge: Pen2-Cys7) (see the related structure in the appendix Figure 1 ).

[0003] Urantide is a peptide-based UT receptor antagonist derived from hUⅡ (Urotensin Ⅱ). Urotensin Ⅱ is a growth hormone-like neuropeptide that was initially isolated from the caudal part of the spinal cord of teleost fish and was later found to be widespread in mammals including humans, and is widely distributed in the spinal cord, brain tissue, and cardiovascular tissue.

[0004] The application of Urantide mainly focuses on its protective effect on myocardial ischemia and ischemia-reperfusion injury. Studies have shown that urantide can reduce membrane lipid peroxidation, increase NO production, reduce calcium overload, etc., thus having a protective effect on the heart muscle.

[0005] In addition, Urantide is also used in the field of scientific research and development. Especially in the research and development of multiple scientific fields such as cancer, immunology, cardiovascular system, respiration, neuroscience, etc., due to the specific chemical structure and properties of Urantide, it can be used as a potential target or tool for studying the disease mechanisms and drug action mechanisms in these fields.

[0006] As a polypeptide drug, the synthesis process of Urantide is relatively complex and requires precise amino acid sequences and specific chemical modifications, which increases the difficulty and cost of production. The synthesis of polypeptide drugs usually requires high-quality raw materials and advanced production equipment, all of which will increase the production cost.

[0007] The current Urantide production scheme on the market is based on the SPPS polypeptide synthesis process, and the target product is oxidized by the air oxidation method, such as the application of Urantide disclosed in Chinese Patent Authorization Publication No. CN104189884A.

[0008] Existing production schemes for Urantide basically adopt the chemical SPPS process. After the polypeptide sequence is completed, the polypeptide is dissolved under weakly alkaline conditions and stirred in air until oxidation is completed. For this process, the present invention has conducted multiple experiments, which prove that there is peptide chain breakage in the Urantide polypeptide before oxidation, with special cleavage sites. At the same time, the oxidation scheme is not satisfactory, and more impurities are generated after oxidation (see appendix Figure 2 ). This is not conducive to large-scale production.

[0009] Therefore, on this basis, the present invention proposes a new synthesis process for Urantide polypeptide. Summary of the Invention

[0010] The purpose of the present invention is to provide a new synthesis process for Urantide polypeptide to solve the problems raised in the above background technology.

[0011] To solve the above technical problems, the present invention provides the following technical solution: A new synthesis process for Urantide polypeptide, S1: Put wang Resin into a reaction tube, add DCM (15 ml / g), and oscillate for 30 min for resin swelling;

[0012] S2: Filter out the solvent, add 3-fold molar excess of Fmoc-Val-OH, dissolve in DMF, then add 3 eq DCC and 0.1 eq DMAP and oscillate for 60 min. After the reaction is completed, cap with acetic anhydride:pyridine (1:1) for 30 min;

[0013] S3: Remove the solvent, add 20% piperidine / DMF solution (15 ml / g) for 5 min, remove and then add 20% piperidine / DMF solution (15 ml / g) for 15 min for deprotection;

[0014] S4: Draw out the piperidine solution, take a dozen resin particles, wash three times with ethanol, add Kaiser reagent, heat at 105 °C - 110 °C for 5 min, and a dark blue color change indicates a positive reaction for detection;

[0015] S5: Wash twice with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g);

[0016] S6: Add 3-fold excess of the amino acid Fmoc-Cys(trt)-OH and HBTU, both dissolved in as little DMF as possible, add to the reaction tube, immediately add 10-fold excess of DIEA, and react for 30 min for linkage;

[0017] S7: Drain the solution, take a dozen resin particles, wash them three times with ethanol, add Kaiser reagent, heat at 105°C - 110°C for 5 min. A colorless result indicates a negative reaction, showing that the reaction is complete for detection.

[0018] S8: Wash once with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g).

[0019] S9: Repeat the operations in steps S3 to S8 above, and sequentially connect Fmoc-Tyr(tbu)-OH, Fmoc-Orn(boc)-OH, Fmoc-D-Trp(boc)-OH, Fmoc-Phe-OH. After completion, use 20% piperidine / DMF solution to remove the Fmoc of the last amino acid to obtain fragment sequence 1.

[0020] Preferably, S10: Put 2 cl CTC Resin into a reaction tube, add DCM (15 ml / g), and shake for 30 min to swell the resin of fragment 2.

[0021] S11: Filter off the solvent, add 3-fold molar excess of Fmoc-Pen-OH, dissolve in DCM, then add 3 eq DIEA and shake for 30 min. After the reaction is completed, add methanol solution to cap for 15 min.

[0022] S12: Remove the solvent, add 20% piperidine / DMF solution (15 ml / g) for 5 min, remove it and then add 20% piperidine / DMF solution (15 ml / g) for 15 min for deprotection.

[0023] S13: Drain the piperidine solution, take a dozen resin particles, wash them three times with ethanol, add Kaiser reagent, heat at 105°C - 110°C for 5 min. A dark blue color indicates a positive reaction for detection.

[0024] S14: Wash twice with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g).

[0025] S15: Add three-fold excess of amino acid Fmoc-Asp(Otbu)-OH and HBTU, both dissolved in as little DMF as possible, add to the reaction tube, immediately add 10-fold excess of DIEA, and react for 30 min for linkage.

[0026] S16: Carry out protected cleavage. Add the Asp(Otbu)-pen resin peptide to 30% trifluoroethanol + 70% DCM solution, stir and react for 2 h. After completion, filter off the resin, and the remaining solution is rotary evaporated to obtain solid powder fragment sequence 2.

[0027] Preferably, after dissolving the fragment sequence 2 in DMF, add it to the fragment sequence 1, along with 3 eq of DIEA and 3 eq of HATU, and stir and react for 30 min to obtain the pre-oxidized disulfide bond end-product resin peptide.

[0028] Preferably, add the resin peptide to 95% TFA, 1% water, 2% EDT, and 2% TIS, shake well and react for 120 min.

[0029] Preferably, dry the cleavage solution as much as possible with nitrogen, wash it six times with ether, and then volatilize it at room temperature to obtain the crude product before oxidation.

[0030] Preferably, take a small sample of the crude product for HPLC analysis. Set the time from 0 - 20 min, set the gradient from 5 - 95 for detection. According to the peak elution time, set the gradient from 35 - 100 to balance the preparative HPLC. The stationary phase of the chromatographic column is alkyl-bonded silica gel, and the mobile phase is acetonitrile-trifluoroacetate solution. Collect the eluate of the target peak.

[0031] Preferably, lyophilize to obtain the white powder-like pre-oxidized end-product of Urantide polypeptide.

[0032] Preferably, after dissolving the pre-oxidized end-product of Urantide polypeptide clearly with 80% water and 20% acetonitrile, add the DMSO / DMF solution with a DMSO concentration of 10% - 20% (v / v), and oxidize for 8 - 12 h until the reaction ends.

[0033] Preferably, obtain the solution-like end-product after rotary evaporation, and then lyophilize again to obtain the white powder-like end-product of Urantide polypeptide.

[0034] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0035] First, in the present invention, through multiple syntheses according to conventional methods and means, it is found that there are always specific impurity products in the mass spectrometry identification of the end product. By comparison, this part of the impurity is the substance of fragment sequence 1. Therefore, theoretically, the reason for the generation of impurity products is the cleavage of the polypeptide sequence, and there are specific inherent impurities. The scheme mentioned in the present invention uses the chemical fragment method, which skips the reaction positions where the polypeptide is prone to cleavage, and can obtain substances without fragment cleavage before oxidation, greatly improving the product yield and reducing the purification difficulty (see attached Figure 4 ).

[0036] Second, in the present invention, the unique DMSO / DMF oxidation condition is adopted, with good oxidation effect, stable oxidation process, and no other obvious impurities in the end product (see attached Figure 5 and 6 ). Brief Description of the Drawings

[0037] Figure 1 It is the structural diagram of Urantide;

[0038] Figure 2 In the middle is the impurity analysis diagram after the existing conventional oxidation method and after oxidizing the disulfide bond;

[0039] Figure 3 Among them, 831.64 is the impurity analysis diagram after the peptide chain breaks at Pen (L-penicillamine);

[0040] Figure 4 Among them, it is obvious that the peak is a clean spectrum without impurities before the disulfide bond of the Urantide polypeptide is oxidized;

[0041] Figure 5 Among them, the obvious peak is the clean spectrum of the final product after the disulfide bond of the Urantide polypeptide is oxidized;

[0042] Figure 6 In the middle is the analysis diagram of the final product through the disulfide bond oxidation scheme. Specific implementation mode

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0044] The present invention provides the following technical solutions:

[0045] Embodiment

[0046] Please refer to Figure 1 、 Figure 3 、 Figure 4 、 Figure 5 and Figure 6 , a new synthesis process of Urantide polypeptide. S1: Put wangResin resin into a reaction tube, add DCM (15 ml / g), and oscillate for 30 min for resin swelling;

[0047] S2: Filter out the solvent, add 3 times the molar excess of Fmoc-Val-OH, dissolve it with DMF, then add 3 eq DCC and 0.1 eq DMAP and oscillate for 60 min. After the reaction is completed, cap it with acetic anhydride:pyridine (1:1) for 30 min;

[0048] S3: Remove the solvent, add 20% piperidine / DMF solution (15 ml / g) for 5 min, remove it and then add 20% piperidine / DMF solution (15 ml / g) for 15 min for deprotection;

[0049] S4: Withdraw the piperidine solution, take a dozen or so resin particles, wash them three times with ethanol, add Kaiser reagent, heat at 105°C - 110°C for 5 min, and perform detection with a dark blue color change indicating a positive reaction;

[0050] S5: Wash twice with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g);

[0051] S6: Add three - fold excess of amino acid Fmoc - Cys(trt)-OH and HBTU, dissolve them both in as little DMF as possible, add them to the reaction tube, immediately add ten - fold excess of DIEA, and react for 30 min for linkage;

[0052] S7: Withdraw the solution, take a dozen or so resin particles, wash them three times with ethanol, add Kaiser reagent, heat at 105°C - 110°C for 5 min, and perform detection with a colorless solution indicating a negative reaction, showing that the reaction is complete;

[0053] S8: Wash once with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g);

[0054] S9: Repeat the above steps S3 to S8, sequentially link Fmoc - Tyr(tbu)-OH, Fmoc - Orn(boc)-OH, Fmoc - D - Trp(boc)-OH, Fmoc - Phe - OH. After completion, use 20% piperidine / DMF solution to remove the Fmoc of the last amino acid to obtain fragment sequence 1.

[0055] Through the above technical solution, first, in the first step, Wang Resin is prepared and placed in a reaction tube. DCM is added with a dosage of 15 ml / g of resin, and it is oscillated for 30 min to fully swell the resin. Then, in the second step, the solvent is removed by suction filtration through a sintered glass filter. 3-fold molar excess of Fmoc-Val-OH is added and dissolved in DMF. Then 3 eq of DCC and 0.1 eq of DMAP are added, and it is oscillated for 60 min for reaction. After the reaction is completed, it is capped with acetic anhydride:pyridine (1:1) for 30 min. Then, in the third step, the deprotection operation is carried out to remove the solvent. 20% piperidine / DMF solution is added with a dosage of 15 ml / g, and after reacting for 5 min, this solution is removed. 20% piperidine / DMF solution is added again with a dosage of 15 ml / g and reacted for 15 min. Subsequently, in the fourth step, the piperidine solution is removed by suction. A dozen or so resin particles are taken, washed three times with ethanol, then Kaiser reagent is added, and it is heated at 105 °C - 110 °C for 5 min. If it turns dark blue, it is a positive reaction indicating successful deprotection. Then, in the fifth step, the washing operation is carried out, alternately washing twice with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g). Then, in the sixth step, 3-fold excess of the amino acid Fmoc-Cys(trt)-OH and HBTU are added and dissolved in as little DMF as possible. The dissolved substance is added to the reaction tube, and immediately 10-fold excess of DIEA is added, and it is reacted for 30 min. In the seventh step, the solution is removed by suction. A dozen or so resin particles are taken, washed three times with ethanol, then Kaiser reagent is added, and it is heated at 105 °C - 110 °C for 5 min. If it is colorless, it is a negative reaction indicating complete reaction. Then, in the eighth step, it is washed once with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g). Finally, in the ninth step, the above operations from S3 to S8 are repeated to sequentially connect Fmoc-Tyr(tbu)-OH, Fmoc-Orn(boc)-OH, Fmoc-D-Trp(boc)-OH, Fmoc-Phe-OH. After completion, the Fmoc of the last amino acid is removed using 20% piperidine / DMF solution to obtain fragment sequence 1.

[0056] S10: Place 2 cl of CTC Resin in a reaction tube, add DCM (15 ml / g), and oscillate for 30 min to swell the resin for fragment 2;

[0057] S11: Filter off the solvent, add 3-fold molar excess of Fmoc-Pen-OH, dissolve it in DCM, then add 3 eq of DIEA and oscillate for 30 min. After the reaction is completed, cap it with methanol solution for 15 min;

[0058] S12: Remove the solvent, add 20% piperidine / DMF solution (15 ml / g), for 5 min, remove and then add 20% piperidine / DMF solution (15 ml / g) again for 15 min for deprotection;

[0059] S13: Suck out the piperidine solution, take a dozen or so resin particles, wash them three times with ethanol, add Kaiser reagent, heat at 105 °C - 110 °C for 5 min, and a dark blue color indicates a positive reaction for detection;

[0060] S14: Wash twice with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g);

[0061] S15: Add three-fold excess of amino acid Fmoc-Asp(Otbu)-OH and HBTU, both dissolved in as little DMF as possible, add to the reaction tube, immediately add ten-fold excess of DIEA, and react for 30 min for linkage;

[0062] S16: Carry out protected cleavage. Add the Asp(Otbu)-pen resin peptide to a 30% trifluoroethanol + 70% DCM solution, stir and react for 2 h. After completion, filter off the resin, and the remaining solution is rotary evaporated to obtain a solid powder fragment sequence 2.

[0063] Through the above technical solution, in the tenth step, put 2cl CTC Resin into the reaction tube, add DCM (15 ml / g), oscillate for 30 min for resin swelling. In the eleventh step, suck out the solvent through a sintered glass filter, add 3-fold molar excess of Fmoc-Pen-OH, dissolve in DCM, then add 3eq DIEA and oscillate for 30 min. After the reaction is completed, add methanol solution to cap for 15 min. In the twelfth step, remove the solvent, add 20% piperidine / DMF solution (15 ml / g), for 5 min, remove and then add 20% piperidine / DMF solution (15 ml / g) again for 15 min for deprotection. In the thirteenth step, suck out the piperidine solution, take a dozen or so resin particles, wash them three times with ethanol, add Kaiser reagent, heat at 105 °C - 110 °C for 5 min, and a dark blue color indicates a positive reaction for detection. In the fourteenth step, wash twice with DMF (10 ml / g), twice with methanol (10 ml / g), and twice with DMF (10 ml / g). In the fifteenth step, add three-fold excess of amino acid Fmoc-Asp(Otbu)-OH and HBTU, both dissolved in as little DMF as possible, add to the reaction tube, immediately add ten-fold excess of DIEA, and react for 30 min for linkage. In the sixteenth step, add the Asp(Otbu)-pen resin peptide to a 30% trifluoroethanol + 70% DCM solution, stir and react for 2 h. After completion, filter off the resin, and the remaining solution is rotary evaporated to obtain a solid powder fragment sequence 2.

[0064] After dissolving the fragment sequence 2 in DMF, it was added to the fragment sequence 1, along with 3 eq of DIEA and 3 eq of HATU, and stirred for reaction for 30 min to obtain the resin peptide as the pre-final product of the disulfide bond oxidation.

[0065] Through the above technical solution, when fragment 2 was dissolved in DMF and then added to the fragment 1 resin, along with 3 equivalents of DIEA and HATU (high-efficiency coupling reagent), and reacted for 30 minutes, the two fragments were connected by an amide bond to form a complete peptide chain (containing two sulfhydryl groups).

[0066] The resin peptide was added to 95% TFA, 1% water, 2% EDT, and 2% TIS, shaken evenly and then reacted for 120 min.

[0067] Through the above technical solution, the resin peptide was added to 95% TFA, 1% water, 2% EDT, and 2% TIS, shaken evenly and then reacted for 120 min for the cleavage reaction. TFA could remove all protecting groups (such as Boc, tBu, Trt, etc.), and EDT and TIS were used as scavengers to prevent oxidation side reactions.

[0068] The cleavage solution was dried as much as possible with nitrogen, washed six times with ether, and then volatilized at room temperature to obtain the crude product before oxidation.

[0069] Through the above technical solution, before the subsequent purification, it was washed six times with ether to remove TFA, and then volatilized at room temperature to obtain the crude product before oxidation.

[0070] A small sample of the crude product was taken for HPLC analysis. The time was set from 0 - 20 min, the gradient was set from 5 - 95 for detection. According to the peak elution time, the gradient was set from 35 - 100 to balance the preparative HPLC. The stationary phase of the chromatographic column was alkyl-bonded silica gel, the mobile phase was acetonitrile-trifluoroacetate solution, and the eluent of the target peak was collected.

[0071] Through the above technical solution, first, a small amount of the crude product was taken as a sample for HPLC analysis. The analysis time was set to 0 - 20 minutes, the gradient was set to 5 - 95 for detection. Then, according to the time of the detected peak, the gradient was adjusted to 35 - 100 to balance the preparative HPLC. During this process, the stationary phase of the chromatographic column was alkyl-bonded silica gel, and the mobile phase was acetonitrile-trifluoroacetate solution. Finally, the eluent of the target peak was collected.

[0072] It was freeze-dried to obtain the pre-final product of the Urantide polypeptide before oxidation in the form of a white powder.

[0073] Through the above technical solution, the eluent of the target peak was collected and freeze-dried. After freeze-drying, the pre-final product before oxidation (containing free sulfhydryl groups) was obtained.

[0074] After dissolving the final product before oxidizing the Urantide polypeptide clearly with 80% water and 20% acetonitrile, add the DMSO / DMF solution with the DMSO concentration of 10% - 20% (v / v), and oxidize for 8 - 12 h until the reaction ends.

[0075] Through the above technical solution, first dissolve the final product before oxidizing the Urantide polypeptide with 80% water and 20% acetonitrile to make the solution clear. Then add the DMSO / DMF solution with the DMSO concentration of 10% - 20% (v / v), and then carry out the oxidation reaction for 8 - 12 h until the reaction ends.

[0076] After rotary evaporation, a solution-like final product is obtained, and then lyophilized again to obtain the white powder-like Urantide polypeptide final product.

[0077] Through the above technical solution, after completing the above series of reaction steps, rotary evaporate the product. At this time, the obtained is a solution-like final product. Then, lyophilize the solution-like final product again to finally obtain the white powder-like Urantide polypeptide final product.

[0078] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A novel synthesis process of Urantide polypeptide, characterized in that: The following steps are involved: S1: Put Wang Resin into a reaction tube, add DCM (15 ml / g), and shake for 30 min to dissolve the resin; S2: Filter off the solvent, add 3-fold molar excess of Fmoc-Val-OH, add DMF to dissolve, then add 3eq DCC and 0.1eq DMAP and shake for 60 min. After the reaction is completed, cap the reaction with acetic anhydride: pyridine (1:1) for 30 min. S3: Remove the solvent, add 20% piperidine / DMF solution (15 ml / g) for 5 min, remove and then add 20% piperidine / DMF solution (15 ml / g) for 15 min for deprotection; S4: Drain the piperidine solution, take a dozen resins, wash them three times with ethanol, add Kaiser reagent, heat at 105℃-110℃ for 5 minutes, and detect when it turns dark blue for positive reaction; S5: Wash with DMF (10 ml / g) twice, methanol (10 ml / g) twice, and DMF (10 ml / g) twice; S6: Add three times excess amino acids Fmoc-Cys(trt)-OH and HBTU, both dissolved in as little DMF as possible, add to the reaction tube, immediately add ten times excess DIEA, and react for 30 minutes for linkage; S7: Drain the solution, take a dozen resins, wash them three times with ethanol, add Kaiser reagent, heat at 105℃-110℃ for 5min, colorless is a negative reaction, indicating that the reaction is complete, and then proceed to detection; S8: Wash with DMF (10 ml / g) once, methanol (10 ml / g) twice, and DMF (10 ml / g) twice; S9: Repeat the above steps S3 to S8 to connect Fmoc-Tyr(tbu)-OH, Fmoc-Orn(boc)-OH, Fmoc-D-Trp(boc)-OH, and Fmoc-Phe-OH in sequence. After completion, use 20% piperidine / DMF solution to remove the Fmoc of the last amino acid to obtain fragment sequence 1.

2. A novel synthesis process of Urantide polypeptide according to claim 1, characterized in that: Also includes: S10: Place 2clCTC Resin in a reaction tube, add DCM (15 ml / g), and shake for 30 min to dissolve the fragment 2 resin; S11: Filter off the solvent, add 3 times molar excess of Fmoc-Pen-OH, add DCM to dissolve, then add 3eq DIEA and shake for 30 min. After the reaction is complete, add methanol solution to seal the head for 15 min; S12: Remove the solvent, add 20% piperidine / DMF solution (15 ml / g) for 5 min, remove and then add 20% piperidine / DMF solution (15 ml / g) for 15 min for deprotection; S13: Drain the piperidine solution, take a dozen resins, wash them three times with ethanol, add Kaiser reagent, heat at 105℃-110℃ for 5min, and detect when it turns dark blue for positive reaction; S14: Wash with DMF (10 ml / g) twice, methanol (10 ml / g) twice, and DMF (10 ml / g) twice; S15: Add three times excess amino acids Fmoc-Asp(Otbu)-OH and HBTU, both dissolved in as little DMF as possible, add to the reaction tube, immediately add ten times excess DIEA, and react for 30 minutes for linkage; S16: Protected cleavage, add Asp(Otbu)-pen resin peptide to 30% trifluoroethanol + 70% DCM solution, stir and react for 2 hours, filter out the resin after completion, and rotary evaporate the remaining solution to obtain solid powder fragment sequence 2.

3. The method for synthesizing Urantide polypeptide according to claim 2, characterized in that: After fragment sequence 2 was dissolved in DMF, it was added to fragment sequence 1, 3eq DIEA, and 3eq HATU, and stirred for reaction for 30 minutes to obtain the final product resin peptide before oxidation of disulfide bonds.

4. A novel synthesis process of Urantide polypeptide according to claim 3, characterized in that: The resin peptide was added with TFA 95%, water 1%, EDT 2%, TIS 2%, and the mixture was shaken evenly and reacted for 120 min.

5. A novel synthesis process of Urantide polypeptide according to claim 4, characterized in that: The cleavage solution was blown dry with nitrogen as much as possible, washed with ether six times, and then evaporated at room temperature to obtain a crude product before oxidation.

6. A novel synthesis process of Urantide polypeptide according to claim 5, characterized in that: Take a small sample of the crude product for HPLC analysis, set the time to 0-20min, set the gradient to 5-95, perform detection, set the gradient to 35-100 equilibrium preparation HPLC according to the peak time, the chromatographic column stationary phase is alkyl bonded silica gel, the mobile phase is acetonitrile-trifluoroacetate solution, and collect the eluent of the target peak.

7. A novel synthesis process of Urantide polypeptide according to claim 6, characterized in that: The final product of Urantide peptide before oxidation was obtained by freeze drying in the form of white powder.

8. A novel synthesis process of Urantide polypeptide according to claim 7, characterized in that: The final product before oxidation of Urantide peptide was dissolved in 80% water and 20% acetonitrile until clear, and then Dmso / DMF solution was added, with the DMSO concentration being 10% to 20% (v / v), and the oxidation was performed for 8 to 12 hours until the reaction was completed.

9. A novel synthesis process of Urantide polypeptide according to claim 8, characterized in that: The final product was obtained as a solution after rotary evaporation, and then freeze-dried again to obtain the final product of Urantide polypeptide as a white powder.

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