A STING small molecule inhibitor, its preparation method and application

Abstract

The present invention discloses a STING small molecule inhibitor, its preparation method and application, belonging to the technical field of synthetic medicine. As an allenyne compound, the STING small molecule inhibitor can act on the stimulator of interferon genes (STING) protein efficiently and specifically, inhibit the cGAS-STING signaling pathway by binding thereto, thereby reducing the type I interferon response induced by HT-DNA. First, the present invention conducts a 1,4-difunctionalization of 1,3-alkene with N-fluorobenzenesulfonimide through copper catalysis, and then uses Raw-lucia / ISG tool cells to screen the biological functions of a large number of synthesized allenyne compounds, thereby obtaining the STING small molecule inhibitor. The STING small molecule inhibitor prepared by the present invention can be applied to the preparation of drugs for type I interferon diseases caused by abnormal activation of the cGAS-STING pathway, and can be combined with acceptable carriers or excipients according to the preparation requirements in the pharmaceutical field to form drugs in various dosage forms such as tablets, capsules, oral liquids, injections, freeze-dried injections for injection or powder injections.

Description

Technical Field

[0001] The present invention belongs to the technical field of synthetic medicine, and particularly relates to a STING small molecule inhibitor, a preparation method thereof, and an application thereof. Background Art

[0002] Interferon (IFN) plays a huge role in the immune function of the body and is closely related to the resistance to pathogen infection, the occurrence and development of tumors and autoimmune diseases. A group of monogenic hereditary immunodeficiency diseases characterized by the overexpression and activation of type I interferon are classified together and are called type I interferonopathies. The abnormal expression of non-inflammatory interferon is often induced by nucleic acids. Cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) has the function of recognizing double-stranded DNA and activates the stimulator of interferon genes (STING). STING is an essential adaptor protein for cytosolic DNA-mediated type I IFN responses. STING can be activated by a variety of cyclic dinucleotides (CDNs), including mammalian 2'3'-cGAMP (produced by DNA-activated cGAS), bacterial second messengers c-di-AMP and c-di-GMP. The human STING protein has four transmembrane regions (NTD, 1-137AA), which anchor the STING protein to the endoplasmic reticulum, a cyclic nucleotide binding region (CBD, 138-240AA), which is the CDN binding region, and a C-terminal region (CTT, 241-379AA). The CCT region has the function of recruiting TANK-binding kinase (TBK1).

[0003] During the activation process of STING, the assembly of STING multimers is accompanied and transported from the Golgi apparatus to the Golgi apparatus, and this process is necessary for the complete activation of STING. STING can not only induce the occurrence of diseases due to abnormal upstream signals, but also its own mutations can lead to the occurrence of autoimmune diseases. For example, STING-associated vasculopathy (SAVI) occurring in infancy is due to abnormal mutations in the STING gene, resulting in the transport of STING from the endoplasmic reticulum to the Golgi apparatus. However, this process often responds to cytoplasmic DNA signaling, and this abnormal process leads to the continuous expression of type I interferon. In addition, more and more evidence indicates that STING plays a pathogenic role in a series of more complex inflammatory diseases. Therefore, STING is an attractive target for treatment and intervention.

[0004] In the exploration of drugs targeting STING, significant progress has been made in both high-throughput drug screening and the development of derivatives of known compounds. However, the screening of STING inhibitors based on large-scale novel compounds still requires continuous exploration. The invention patent with the publication number CN114533715A provides a small molecule inhibitor targeting the STING target and its applications. The small molecule inhibitor is one or more of arachidonic acid or its derivatives, analogs, and pharmaceutically acceptable salts. However, as a common essential fatty acid, arachidonic acid can be transformed into various metabolites in the body and is involved in inflammatory reactions. How to enable arachidonic acid or its derivatives and analogs to maintain the biological function of inhibiting inflammation under specific circumstances has not been solved yet. The invention with the publication number CN107335049A discloses the application of Asteraceae-type cyclic peptide compounds as inhibitors of the cGAS-STING signaling pathway, revealing that Asteraceae-type cyclic peptide compounds are inhibitors of the cGAS-STING signaling pathway. However, this invention can only inhibit the expression of downstream genes IFNβ, IFNα4, and CXCL10 of the cGAS-STING signaling pathway stimulated by the DNA analog ISD, and does not mention the expression of type I interferon induced by HT-DNA. Summary of the Invention

[0005] To solve the problems existing in the prior art, the purpose of the present invention is to provide a STING small molecule inhibitor, its preparation method and applications, which can efficiently and specifically act on the stimulator of interferon genes (STING) protein, and inhibit the cGAS-STING signaling pathway by binding to it, thereby reducing the type I interferon response induced by HT-DNA.

[0006] The technical solution of the present invention is as follows:

[0007] One of the purposes of the present invention is to provide a STING small molecule inhibitor, and the STING small molecule inhibitor is an allene compound with the following structure:

[0008] 。

[0009] Another purpose of the present invention is to provide a preparation method of a STING small molecule inhibitor. An allene compound is synthesized by copper-catalyzed 1,4-difunctionalization of 1,3-alkenes and N-fluorobenzenesulfonimide, and then a large number of synthesized allene compounds are screened for biological functions using tool cells, thereby obtaining a STING small molecule inhibitor. The tool cells are Raw-lucia / ISG tool cells.

[0010] Furthermore, the synthesis reaction process of the allene compound is as follows:

[0011]

[0012] Among them, S1 is phenylbutanone, S2 is p-methylphenylacetylene, S3 is 1-p-methylphenyl-3-phenyl-3-hexyn-1-ol, and S4 is 1-p-methylphenyl-3-phenyl-3-hexen-1-yn.

[0013] Furthermore, it includes the following steps:

[0014] (1) Charge p-methylphenylacetylene and tetrahydrofuran into a round-bottom flask, cool the solution and add n-butyllithium, stir the resulting solution at room temperature and then cool it again, add phenylbutanone dropwise, warm the reaction mixture to room temperature and monitor the completion of the reaction;

[0015] (2) When completed, quench the reaction mixture with saturated aqueous NH4Cl solution, extract the aqueous layer with ethyl acetate and wash the combined organic layers with brine, dry over MgSO4 and filter, then concentrate under reduced pressure to obtain the raw material 1-p-methylphenyl-3-phenyl-3-hexyn-1-ol;

[0016] (3) Dissolve the obtained crude 1-p-methylphenyl-3-phenyl-3-hexyn-1-ol in dry dichloromethane, cool the mixture to 0 °C with a cooling bath, add triethanolamine and methanesulfonyl chloride to this solution in sequence, after sufficient reaction, monitor the completion of the reaction;

[0017] (4) When the reaction is completed, quench the reaction product with saturated aqueous NH4Cl solution, extract the aqueous layer with ethyl acetate and wash the combined organic layers with brine, dry over MgSO4 and filter, then concentrate under reduced pressure, purify the crude extract by flash chromatography to obtain 1-p-methylphenyl-3-phenyl-3-hexen-1-yn;

[0018] (5) In a dry sealed tube, dissolve copper(I) thiophene-2-carboxylate and 1,10-phenanthroline in CH3CN under a nitrogen atmosphere and stir the mixture at room temperature, then add 1-p-methylphenyl-3-phenyl-3-hexen-1-yn, N-fluorobenzenesulfonimide and trimethylsilyl cyanide in sequence, stir the reaction mixture, evaporate the solvent under reduced pressure after the reaction is completed, purify the residue by flash column chromatography on silica gel to obtain the light yellow solid 1,4-sulfonimide-cyanated allene, namely the STING small molecule inhibitor.

[0019] Furthermore, in the step (1), the amount of p-methylphenylacetylene is 1 equivalent (20 mmol), the amount of n-BuLi is 1 equivalent (2.5 M in THF, 8 mL, 20 mmol), and the amount of phenylbutanone is 1 equivalent (20 mmol).

[0020] Furthermore, in the steps (1) and (3), TLC thin layer chromatography is used to monitor the completion of the reaction.

[0021] Further, in the step (3), 5 equivalents (100 mmol) of triethanolamine and 2.5 equivalents (50 mmol) of methylsulfonyl chloride are used.

[0022] Further, in the step (5), 1 equivalent (20 mmol) of 1-(p-tolyl)-3-phenylhex-3-en-1-yne, 1.5 equivalents (30 mmol) of N-fluorobenzenesulfonimide, and 1.5 equivalents (30 mmol) of trimethylsilyl cyanide are used.

[0023] A third object of the present invention is to provide an application of a STING small molecule inhibitor in the preparation of a drug for treating type I interferon diseases caused by abnormal activation of the cGAS-STING pathway. The STING small molecule inhibitor can specifically inhibit the type I interferon response induced by HT-DNA and is formulated into a drug in combination with acceptable carriers and excipients according to the preparation requirements in the pharmaceutical field.

[0024] Further, the dosage form of the drug is tablets, capsules, oral liquids, injections, freeze-dried injections for injection, or powder injections.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. The present invention for the first time reveals that 1,4-sulfonylimide-cyanated allelene and its racemates, stereoisomers, tautomers, polymorphs, and solvates are used as an inhibitor of the cGAS-STING signaling pathway. This compound can act on the STING protein efficiently and selectively, effectively inhibit the expression of type I interferon genes caused by the cGAS-STING signaling pathway under HT-DNA stimulation, and can be applied to the preparation of drugs for diseases caused by abnormal activation of the cGAS-STING signaling pathway, especially for autoimmune-related diseases caused by STING protein mutations, and can meet the diverse requirements of drug dosage forms and administration methods, having broad clinical application prospects.

[0027] 2. During the conduction of innate immune signaling pathways, the cGAS-STING pathway and the RIG-MAVS pathway mediate DNA and RNA immune responses, respectively, leading to the expression of IFN-β and downstream ISG cytokines. Therefore, exogenous stimulation with HT-DNA and POLY(I:C) (RNA analogs) can reflect the activation of the cGAS-STING and RIG-MAVS pathways. In the preparation method, the present invention creatively selects Raw-Lucia / ISG cells as tool cells for biological function screening of ligand compounds. Using the Lucia luciferase reporter gene induced by interferon regulatory factors (IRFs), changes in Lucia content in the culture supernatant can be detected, thereby determining the activation of the cGAS-STING and RIG-MAVS pathways and quickly and accurately screening for STING small molecule inhibitors.

[0028] 3. The target of the STING small molecule inhibitor described in the present invention is STING, which can effectively inhibit the IFNβ downstream response induced by STING overexpression and has the effect of specifically inhibiting the cGAS-STING pathway. Therefore, when this STING small molecule inhibitor is used in the preparation of drugs for type I interferon diseases, it can not only effectively treat type I interferon diseases induced by TREX1 gene deletion, including AGS, familial pernio-like lupus, systemic lupus erythematosus and leukodystrophy-related retinopathy, but also provide theoretical support for the use of this STING small molecule inhibitor in the clinical treatment of type I interferon diseases. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the synthesis technology route of the STING small molecule inhibitor described in the present invention;

[0030] Figure 2 A is the cytotoxicity assay result of the STING small molecule inhibitor in Raw-lucia / ISG cells in Comparative Example 1 of the present invention; Figure 2 B is the inhibitory effect of STING small molecule inhibitors on IFN-β response induced by HT-DNA and POLY(I:C);

[0031] Figure 3 The results of determining the target locations of the STING small molecule inhibitors in Comparative Examples 2 and 3 of the present invention are as follows;

[0032] Figure 4 AC is detected by qPCR in Comparative Example 4 of the present invention Trex1 - / - Changes in cardiac inflammatory factor levels in mice after treatment; Figure 4 DG was detected by flow cytometryTrex1 - / - Changes in the level of activated T cells after mouse treatment. Specific implementation manners

[0033] The present invention will be further described below in conjunction with the accompanying drawings and preferred embodiments. The provided embodiments are only for clarifying the present invention and not for limiting the scope of the present invention.

[0034] The materials, reagents, etc. used in the following embodiments can be obtained from commercial channels without special instructions;

[0035] The experimental methods in the following embodiments are all conventional methods without special instructions;

[0036] All the experiments in the following embodiments were independently completed at least 3 times, and all results were expressed as mean ± standard deviation (SD);

[0037] Two groups of data were analyzed by t-test, and multiple groups of data were analyzed by one-way ANOVA;

[0038] The statistical tests performed are illustrated in the figure: *p < 0.05, **p < 0.01, p < 0.001, ****p < 0.0001, and a p-value < 0.05 was considered significant.

[0039] Example 1

[0040] This example provides a STING small molecule inhibitor, and its preparation method includes the following steps:

[0041] (1) Charge 20 mmol, 1 equivalent of p-methylphenylacetylene and 40 mL of tetrahydrofuran into a 100 mL round-bottom flask. Cool the solution to -78 °C and add n-butyllithium. Stir the resulting solution at room temperature for 20 min and then cool it to -78 °C again. Dropwise add 20 mmol, 1 equivalent of phenylbutanone, and allow the reaction mixture to warm to room temperature and monitor the completion of the reaction by TLC;

[0042] (2) When completed, quench the reaction mixture with 40 mL of saturated aqueous NH4Cl solution, extract the aqueous layer with ethyl acetate, and wash the combined organic layers with 30 mL of brine. Dry over MgSO4 and filter, then concentrate under reduced pressure to obtain the raw material 1-p-methylphenyl-3-phenyl-3-hexyn-1-ol;

[0043] (3) Dissolve the obtained crude 1-p-methylphenyl-3-phenyl-3-hexyn-1-ol in 40 mL of dry dichloromethane. Cool the mixture to 0 °C with a cooling bath, and sequentially add 100 mmol, 5 equivalents of triethanolamine and 50 mmol, 2.5 equivalents of methanesulfonyl chloride to the solution. Monitor the completion of the reaction by TLC after 30 min;

[0044] (4) Upon completion, the reaction mixture was quenched with 40 mL of saturated aqueous NH4Cl, the aqueous layer was extracted with ethyl acetate and the combined organic layers were washed with 30 mL of brine, dried over MgSO4 and filtered, then concentrated under reduced pressure. The crude product was purified by flash chromatography to obtain 1-p-tolyl-3-phenyl-3-hexen-1-yne.

[0045] (5) In a dry sealed tube, 0.025 mmol, 5 mol % of copper(I) thiophene-2-carboxylate and 0.035 mmol, 7 mol % of 1,10-phenanthroline were dissolved in 2 mL of CH3CN under a nitrogen atmosphere and the mixture was stirred at room temperature for 30 min. Then, 0.5 mmol, 1 equiv of 1-p-tolyl-3-phenyl-3-hexen-1-yne, 0.75 mmol, 1.5 equiv of N-fluorobenzenesulfonimide and 0.75 mmol, 1.5 equiv of trimethylsilyl cyanide were added successively. The reaction mixture was stirred for 12 h. After completion of the reaction, the solvent was evaporated under reduced pressure and the residue was purified by flash column chromatography on silica gel to give a pale yellow solid of 1,4-sulfonimide-cyanated allene, namely the STING small molecule inhibitor.

[0046] Among them, the NMR spectrum of 1-p-tolyl-3-phenyl-3-hexen-1-yne is as follows: 1 H NMR (600 MHz, CDCl3) δ 7.68 (d, J = 7.4 Hz, 2H), 7.37 (t, J = 6.9 Hz, 2H), 7.32 - 7.26 (m, 2H), 7.17 (d, J = 7.2 Hz, 1H), 6.45 (t, J = 6.8 Hz, 2H), 2.61 (p, J = 7.4 Hz, 2H), 2.38 (s, 3H), 1.18 (t, J = 7.5 Hz, 3H);

[0047] 13 C NMR (150 MHz, CDCl3) δ 140.08, 138.49, 138.39, 131.52, 129.21, 128.44, 127.50, 126.10, 123.11, 120.63, 95.43, 86.18, 24.85, 21.61, 13.69).

[0048] The NMR spectrum of 1,4-sulfonimide-cyanated allene is as follows: 11H NMR (600 MHz, CDCl3) δ 8.06 - 7.92 (m, 1H), 7.89 - 7.66 (m, 5H), 7.65 - 7.51 (m, 3H), 7.49 - 7.21 (m, 11H), 5.36 - 5.32 (m, 1H), 2.36 (s, 3H), 2.30 - 2.13 (m, 1H), 1.69 - 1.56 (m, 1H), 0.96 (t, J = 7.1 Hz, 3H);

[0049] 13 13C NMR (150 MHz, CDCl3) δ 214.30, 139.66, 135.95, 133.92, 132.89, 130.01, 129.94, 129.57, 129.11, 129.08, 128.91, 128.58, 128.21, 126.40, 126.22, 116.14, 113.53, 90.88, 63.86, 27.79, 21.40, 12.69).

[0050] Comparative Example 1

[0051] This comparative example provides cytotoxicity testing of STING small molecule inhibitors in Raw-lucia / ISG cells and inhibitory effect testing on HT-DNA and POLY(I:C)-stimulated IFNβ responses, including the following steps:

[0052] (1) The cell viability was detected using a CCK-8 kit (TransGen Biotech, Beijing, China). The cells were seeded in a 96-well plate at 100 μL / well and 1×104 cells / mL for 24 h, then different concentrations of STING small molecule inhibitors were added and incubated at 37 °C for different times.

[0053] (2) CCK-8 solution was added to each well plate, then incubated at 37 °C for 1 h, and the absorbance at 450 was measured to calculate the cell inhibition rate. The calculation formula is as follows: Cell inhibition rate = [1 - (ODexperimental - ODblank) / (ODcontrol - ODblank)] × 100%.

[0054] (3) All experiments were repeated 3 times and independently replicated 3 times. RAW264.7 LuciaTM ISG cells were seeded in a 96-well plate and treated with the specified dose of STING small molecule inhibitor. After 12 h, HT-DNA and poly(I:C) were transfected respectively, and the luciferase activity in the cell supernatant was detected after static culture for 16 h.

[0055] Comparative Example 2

[0056] This comparative example provides a test for the action target position of the STING small molecule inhibitor, including the following steps:

[0057] (1) Pretreat 1.5 × 106 cells / mL of Raw264.7 cells with the STING small molecule inhibitor for 12 hours, and then stimulate with 250 μg / mL and 20 μg / mL of CMA DMXAA for 2 hours, and then stimulate with 0.5 μg / mL of cGAMP for 4 hours to collect samples. −1 of Raw264.7 cells in the STING small molecule inhibitor for 12 hours, and then with 250 μg / mL −1 and 20 μg / mL −1 CMA DMXAA for 2 h, and then with 0.5 μg / mL −1 cGAMP for 4 h to collect samples.

[0058] (2) Use TRIzol reagent to extract the total RNA of the cells, perform reverse transcription using the cDNA Synthesis Kit, and then use FastStart Universal SYBR Green Master (Rox) for real-time quantitative PCR to detect gene transcripts. The thermal cycling conditions are: 95°C for 10 min; 95°C for 15 s, 58°C for 30 s, 72°C for 30 s, for a total of 40 cycles, with GAPDH as the internal reference gene.

[0059] Comparative Example 3

[0060] This comparative example provides a test for the action target of the STING small molecule inhibitor, including the following steps:

[0061] (1) Transfect 1.0×106 cells / mL of HEK293T with pCDNA3.1-Flag-STING, pCDNA3.1-Flag-TBK1, pCDNA3.1-Flag-IRF3, pCDNA3.1-Flag-MAVS. After 6 hours of transfection, replace the medium with the STING small molecule inhibitor and DMSO respectively and culture overnight. After 16 - 18 hours, collect the samples and detect the change of the IFN-β downstream cytokine CXCL10 by qPCR. −1 HEK293T cells were transfected with pCDNA3.1-Flag-STING, pCDNA3.1-Flag-TBK1, pCDNA3.1-Flag-IRF3, pCDNA3.1-Flag-MAVS. After 6 h of transfection, the medium was replaced with the medium containing the STING small molecule inhibitor and DMSO respectively and cultured overnight. After 16 - 18 h, the samples were collected and the change of the IFN-β downstream cytokine CXCL10 was detected by qPCR.

[0062] (2) Wash the HEK293T cells in PBS and dissolve them in the lysis buffer containing protease and phosphatase inhibitors for 30 minutes, including 50 mM Tris-Cl, 150 mM NaCl, 1 mM EDTA, 0.5 mM EGT A, 10% glycerol, 0.5% NP40 at pH 7.5.

[0063] (3) Centrifuge the reaction mixture at 13000 rpm for 10 min and collect the supernatant, and perform Western blot detection after denaturation.

[0064] Comparative Example 4

[0065] This comparative example provides a feasibility test of a STING small molecule inhibitor in the treatment of type I interferon diseases, including the following steps:

[0066] (1) Wild-type mice at 4-5 weeks of age and Trex1 - / - mice were randomly divided into WT+DMSO, Trex1 - / - +DMSO, WT+DWL-4-140, Trex1 - / - +DWL-4-140 groups. 200 μl of STING small molecule inhibitor and DMSO were respectively injected intraperitoneally. Among them, 5% DMSO, 10% PEG300, and 2.5% Tween-80 were dissolved in PBS, once a day for 30 days.

[0067] (2) Mouse blood was collected by orbital blood sampling to obtain serum. The mice were euthanized with CO2, and the mouse heart tissue was collected for qPCR to detect the changes in inflammatory factors.

[0068] (3) The mouse spleen was collected and separated, and then filtered through a cell strainer in PBS containing 1% FBS. The cells were collected by centrifugation at 1500 rpm for 5 min. Red blood cells were removed with red blood cell lysis buffer. The remaining cells were resuspended and incubated with antibodies CD3-BV421, CD4-PECy7, CD8-BB515, and CD69-BV711 in the dark on ice for 20 min. The separated cells were resuspended in PBS and analyzed with a FACSymphonyTM A5 instrument.

[0069] As Figure 2 shown in A, the STING small molecule inhibitor has basically no cytotoxicity at the indicated concentration. The STING small molecule inhibitor can effectively inhibit the IFN-β response induced by HT-DNA, and there is a dose effect; as Figure 2 shown in B, it has basically no effect on the IFN-β response induced by POLY(I:C), indicating that the STING small molecule inhibitor has a specific effect of inhibiting the cGAS-STING pathway.

[0070] As Figure 3 shown in A, the STING small molecule inhibitor can effectively inhibit the IFN-β response induced by the STING agonist. This indicates that the target of the STING small molecule inhibitor should be on or downstream of STING; as Figure 3As shown in Figure B, the STING small molecule inhibitor can effectively inhibit the downstream response of IFN-β induced by overexpression of STING, but has no response to the downstream response of IFNβ induced by overexpression of TBK1, IRF3, or MAVS. Therefore, it can be inferred that the target of the STING small molecule inhibitor is STING.

[0071] As Figure 4 shown in A-C, Trex1 - / - After treatment with the STING small molecule inhibitor, the lupus phenotype of the mice was significantly alleviated. Trex1 - / - The levels of cardiac inflammatory factors in the mice decreased significantly; as Figure 4 shown in D-G, the levels of similarly activated T cells were also improved, indicating that the STING small molecule inhibitor can effectively treat type I interferon diseases induced by TREX1 gene deletion, and also providing a theoretical basis for the use of the STING small molecule inhibitor in the clinical treatment of type I interferon diseases.

[0072] The above are only embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A STING small molecule inhibitor, characterized in that: The STING small molecule inhibitor is an allene compound with the following structure: 。 2. A method for preparing the STING small molecule inhibitor according to claim 1, characterized in that, The allene compound is synthesized by copper-catalyzed 1,4-difunctionalization of 1,3-alkenes with N-fluorobenzenesulfonimide, and then a large number of synthesized allene compounds are screened for biological functions using tool cells, and the tool cells are Raw-lucia / ISG tool cells, so as to obtain the STING small molecule inhibitor.

3. The preparation method of a STING small molecule inhibitor according to claim 2, characterized in that, It includes the following steps: (1) Charge p-methylphenylacetylene and tetrahydrofuran into a round-bottom flask, cool the solution and add n-butyllithium (n-BuLi), stir the resulting solution at room temperature and then cool it again, and add phenylbutanone dropwise, heat the reaction mixture to room temperature and monitor the completion of the reaction; (2) At the completion, quench the reaction mixture with saturated aqueous NH4Cl solution, extract the aqueous layer with ethyl acetate and wash the combined organic layers with brine, dry over MgSO4 and filter, and then concentrate under reduced pressure to obtain the raw material 1-p-methylphenyl-3-phenyl-3-hexyn-1-ol; (3) Dissolve the obtained crude 1-p-methylphenyl-3-phenyl-3-hexyn-1-ol in dry dichloromethane, cool the mixture to 0 °C with a cooling bath, and sequentially add triethanolamine and methanesulfonyl chloride to this solution, after sufficient reaction, monitor the completion of the reaction; (4) At the completion of the reaction, quench the reaction product with saturated aqueous NH4Cl solution, extract the aqueous layer with ethyl acetate and wash the combined organic layers with brine, dry over MgSO4 and filter, and then concentrate under low pressure, and the crude extract is purified by flash chromatography to obtain 1-p-methylphenyl-3-phenyl-3-hexen-1-yn; (5) In a dry sealed tube, dissolve copper(I) thiophene-2-carboxylate and 1,10-phenanthroline in CH3CN under a nitrogen atmosphere, stir the mixture at room temperature, and then sequentially add 1-p-methylphenyl-3-phenyl-3-hexen-1-yn, N-fluorobenzenesulfonimide and trimethylsilyl cyanide, stir the reaction mixture, evaporate the solvent under low pressure after the reaction is completed, and purify the residue by flash column chromatography on silica gel to obtain the 1,4-sulfonimide-cyanated allene in the form of a pale yellow solid, that is, the STING small molecule inhibitor.

4. The preparation method of a STING small molecule inhibitor as described in claim 3, characterized in that, In the step (1), p-methylphenylacetylene is 1 equivalent, n-butyllithium (n-BuLi) is 1 equivalent of a 2.5 M THF solution, and phenylbutanone is 1 equivalent.

5. The preparation method of a STING small molecule inhibitor according to claim 3, characterized in that, In the steps (1) and (3), TLC thin layer chromatography is used to monitor the completion of the reaction.

6. The preparation method of a STING small molecule inhibitor according to claim 3, characterized in that, In the step (3), triethanolamine is 5 equivalents and methanesulfonyl chloride is 2.5 equivalents.

7. The preparation method of a STING small molecule inhibitor according to claim 3, characterized in that In the step (5), 1-p-methylphenyl-3-phenyl-3-hexen-1-yn is 1 equivalent, N-fluorobenzenesulfonimide is 1.5 equivalents, and trimethylsilyl cyanide is 1.5 equivalents.

8. Use of a STING small molecule inhibitor as described in claim 1 in the preparation of a medicament for type I interferon diseases caused by abnormal activation of the cGAS-STING pathway, characterized in that, The STING small molecule inhibitor can specifically inhibit the type I interferon response induced by HT-DNA, and is formulated into a drug according to the preparation requirements in the pharmaceutical field and in combination with acceptable carriers and excipients.

9. Use of a STING small molecule inhibitor as described in claim 8, characterized in that, The dosage form of the drug is tablets, capsules, oral liquids, injections, freeze-dried injections for injection or powder injections.

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