Manganese salt synthesis of sting agonist msa-2 and tumor treatment applications

Abstract

The application provides a manganese salt synthesis of a STING agonist MSA-2 and tumor treatment applications, and relates to the biomedical technical field, wherein the preparation method of the manganese salt of the STING agonist MSA-2 is as follows: S1: 4-(5,6-dimethoxybenzo[B]thiophene-2-yl)-4-oxobutanoic acid and sodium hydroxide are put into a reactor, purified water is added, reaction is carried out at room temperature for 12 hours, the reaction is stopped, and the reaction is not further treated and is left for use in the next step; S2: manganese chloride is taken, dissolved in purified water and then added to the solution in the first step, reaction is carried out at room temperature for 24 hours, the reaction is stopped after waiting for the reaction to be completed, solid is obtained through suction filtration, is recrystallized with water and then dried, and finally the compound is obtained and is recorded as MSA-2-Mn. The metal cation Mn is used to modify the STING agonist, the cGAS-STING signal path is efficiently activated through the Mn, the MSA-2 can be selectively targeted to tumor tissues, shows higher activation STING path capacity, and the effect of tumor immunotherapy is realized.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, and in particular to the synthesis of manganese salts of the STING agonist MSA-2 and their application in tumor therapy. Background Technology

[0002] The cyclic GMP-AMP synthase (cGAS)-interferon gene stimulating factor (STING) signaling pathway responds to double-stranded DNA stimulation, activating innate and adaptive immunity and playing a crucial role in anti-cancer immunity. cGAS binds to double-stranded DNA (dsDNA) and catalyzes the synthesis of the second messenger cGAMP from GTP and ATP. cGAMP binds to STING on the downstream endoplasmic reticulum (ER), promoting a significant conformational change in the STING dimer and triggering its transport from the ER to the Golgi apparatus. In the Golgi apparatus, STING is recruited, and phosphorylation of TBK1 leads to the recruitment of interferon regulatory factor 3 (IRF3), driving the expression of type I interferon IFN-β, thereby inhibiting tumor growth.1

[0003] Recent studies have found that MSA-2 is an orally administered non-nucleotide STING agonist. Due to its unique non-covalent dimer structure, it can effectively activate the STING pathway. Furthermore, MSA-2 is weakly acidic, exhibiting higher permeability in the weakly acidic tumor microenvironment. This allows MSA-2 to enter tumor tissue more extensively, demonstrating a higher ability to activate the STING pathway, thereby more effectively activating the immune system and killing cancer cells. Therefore, further modification and improvement of MSA-2's therapeutic effect on tumors is of great significance. Summary of the Invention

[0004] The purpose of this invention is to synthesize manganese salt modified MSA-2 (MSA-2-Mn), so that MSA-2-Mn can release MSA-2 and Mn at the tumor site. Mn can efficiently activate the cGAS-STING signaling pathway, while MSA-2 can selectively target tumor tissue. The combined effect of the two can significantly enhance the anti-tumor immunotherapy effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A manganese salt (MSA-2-Mn) of the STING agonist MSA-2, the chemical formula of which is shown below:

[0007]

[0008] Preferably, the synthesis route of MSA-2-Mn is as follows:

[0009]

[0010] Preferably, S1: 4-(5,6-dimethoxybenzo[B]thiophen-2-yl)-4-oxobutyric acid and sodium hydroxide are placed in a reactor, purified water is added, and the reaction is carried out at room temperature for 12 hours. The reaction is then stopped, and the reaction is not further processed and is reserved for the next step.

[0011] S2: Take manganese chloride, dissolve it in purified water and add it to the solution from step one. React at room temperature for 24 hours. After the reaction is complete, stop the reaction, filter to obtain a solid, recrystallize it with water and dry it to obtain the compound, denoted as MSA-2-Mn.

[0012] Preferably, in S1, the mass of 4-(5,6-dimethoxybenzo[B]thiophen-2-yl)-4-oxobutyric acid is 58.8 mg (0.2 mmol), and the mass of sodium hydroxide is 8.0 mg (0.2 mmol).

[0013] Preferably, the manganese chloride in S2 is weighed at 12.6 mg (0.1 mmol).

[0014] Preferably, the characterization data of the 1H NMR spectrum of the MSA-2-Mn are as follows: 1H NMR (400MHz, DMSO) δ 8.32 (s, 2H), 7.59-7.48 (m, 4H), 4.18-4.17 (m, 6H), 3.86-3.85 (m, 6H), 2.68 (s, 4H), 1.99 (s, 4H).

[0015] This application also provides the use of the manganese salt of the STING agonist MSA-2 in the preparation of a tumor treatment drug, wherein the manganese salt of the STING agonist MSA-2 is the manganese salt of the STING agonist MSA-2 described above.

[0016] Preferably, the MSA-2-Mn releases Mn and MSA-2 at the tumor site. Mn efficiently activates the cGAS-STING signaling pathway, while MSA-2 can selectively target tumor tissue, exhibiting a higher ability to activate the STING pathway.

[0017] The method for preparing the manganese salt of the STING agonist MSA-2 provided in this application utilizes the metal cation Mn to modify the STING agonist. Mn efficiently activates the cGAS-STING signaling pathway, while MSA-2 can selectively target tumor tissue, exhibiting a higher ability to activate the STING pathway and achieve the effect of tumor immunotherapy. The STING agonist drug MSA-2-Mn containing the cation Mn provided in this application can significantly improve the detection sensitivity of cGAS for DNA and promote its synthesis of the second messenger cGAMP. It can also enhance the binding ability of STING to cGAMP, and has a dual activation effect on the cGAS-STING pathway, providing a promising strategy for enhancing chemotherapy and immunotherapy. Attached Figure Description

[0018] Figure 1 This is a diagram illustrating the mouse treatment steps and experimental results of the verification experiment in Example 2 of the present invention.

[0019] Specifically, this is a schematic diagram illustrating the treatment strategy for B16F10 tumors;

[0020] Figure 2 These are the tumor growth curves of each group of mice in Example 2 of the present invention;

[0021] Figure 3 This is a curve comparing the tumor volume of each group of mice in Example 2 of the present invention;

[0022] Figure 4 This is a graph showing the changes in the survival curves of mice in each group in Example 2 of this application. Detailed Implementation

[0023] This application provides a manganese salt (MSA-2-Mn) of the STING agonist MSA-2, with the following chemical formula:

[0024]

[0025] The synthesis route of MSA-2-Mn is shown below:

[0026]

[0027] This application also provides the application of MSA-2-Mn in the preparation of antitumor drugs, wherein MSA-2-Mn releases Mn and MSA-2 at the tumor site, Mn efficiently activates the cGAS-STING signaling pathway, and MSA-2 can selectively target tumor tissue, exhibiting a higher ability to activate the STING pathway.

[0028] The present application will be described below with reference to specific embodiments:

[0029] Example 1: Preparation of MSA-2-Mn

[0030] S1: Weigh 58.8 mg (0.2 mmol) of 4-(5,6-dimethoxybenzo[B]thiophen-2-yl)-4-oxobutyric acid and 8.0 mg (0.2 mmol) of sodium hydroxide into a reactor, add purified water, react at room temperature for 12 hours, stop the reaction, and leave the reaction for the next step without further processing;

[0031] S2: Weigh 12.6 mg (0.1 mmol) of manganese chloride, dissolve it in purified water and add it to the solution from step one. React at room temperature for 24 hours. After the reaction is complete, stop the reaction, filter to obtain a solid, recrystallize it with water and dry it to obtain 52.56 mg of the compound, denoted as MSA-2-Mn.

[0032] The characterization data of the obtained MSA-2-Mn 1H NMR spectrum are as follows: 1H NMR (400MHz, DMSO) δ 8.32 (s, 2H), 7.59-7.48 (m, 4H), 4.18-4.17 (m, 6H), 3.86-3.85 (m, 6H), 2.68 (s, 4H), 1.99 (s, 4H).

[0033] 13 The 13C NMR spectrum is as follows: 13C NMR (100MHz, DMSO) δ 199.22, 199.10, 189.98, 189.26, 181.31, 177.93, 165.79, 149.96, 149.92, 149.24, 149.20, 139.77, 138.81, 109.15, 107.06, 107.02, 106.95, 106.91, 49.24, 49.23, 49.21, 49.17, 33.16, 32.95, 31.59, 30.62.

[0034] IR(KBr,ν,cm -1 ):3078,2937,1605,1552,1360,1298,1148,1060,1029,613;

[0035] HRMS(ESI-TOF):m / z calcd for:C28H27MnO10S2,642.0426[M+H]+; found:642.0429.

[0036] Example 2: Verification of the antitumor effect of MSA-2-Mn

[0037] Six- to eight-week-old C57BL / 6 female mice were selected and injected subcutaneously with B16F10 cells (2 x 10⁻⁶).5 A mouse tumor model was established, and the tumor volume reached 100 mm². 3 The mice were divided into three groups: Control, MSA-2, and MSA-2-Mn (n=8 per group).

[0038] Three groups of mice were injected three times in situ into the tumor, one with Control (50 mg / kg MSA-2) and the other with MSA-2-Mn (50 mg / kg MSA-2-Mn). (The Control group was injected with a solution of 10% DMSO + 40% PEG300 + 50% (0.9%) NaCl. The solutions for MSA-2 and MSA-2-Mn were 10% DMSO + 40% PEG300 + 50% (0.9%) NaCl.) Please refer to [link / reference]. Figure 1 After the injection is completed on the seventh day, another injection is given every three days, for a total of three injections.

[0039] After injection, the mice were cultured in the same environment, and the survival rate and tumor size of the mice were observed.

[0040] Please see Figure 2 and Figure 3 After treatment with MSA-2-Mn, the size and volume of tumors in mice decreased significantly compared with the control group.

[0041] Please see Figure 4 After treatment with MSA-2-Mn, the survival rate of mice was significantly prolonged compared with that of the control group.

[0042] In summary, the method for preparing the manganese salt of the STING agonist MSA-2 provided in this application utilizes the metal cation Mn to modify the STING agonist. Through the efficient activation of the cGAS-STING signaling pathway by Mn, MSA-2 can selectively target tumor tissue. The combined effect of both significantly enhances the efficacy of anti-tumor immunotherapy. The STING agonist drug MSA-2-Mn containing the cation Mn provided in this application can significantly improve the detection sensitivity of cGAS for DNA and promote its synthesis of the second messenger cGAMP. It can also enhance the binding ability of STING to cGAMP, and has a dual activation effect on the cGAS-STING pathway, providing a promising strategy for enhancing chemotherapy and immunotherapy.

Claims

1. A STING agonist MSA-2-Mn, characterized in that: The chemical formula of MSA-2-Mn is shown below: 。 2. A method for preparing the STING agonist MSA-2-Mn, used to prepare the STING agonist MSA-2-Mn according to claim 1, characterized in that: The synthesis route of MSA-2-Mn is shown below: 。 3. The method for preparing the STING agonist MSA-2-Mn according to claim 2, characterized in that: The preparation method of MSA-2-Mn is as follows: S1: Take 4-(5,6-dimethoxybenzo[B]thiophen-2-yl)-4-oxobutyric acid and sodium hydroxide into a reactor, add purified water, react at room temperature for 12 hours, stop the reaction, and leave the reaction for the next step without further processing. S2: Take manganese chloride, dissolve it in purified water and add it to the solution from step one. React at room temperature for 24 hours. After the reaction is complete, stop the reaction, filter to obtain a solid, recrystallize it with water and dry it to obtain the compound, denoted as MSA-2-Mn.

4. The method for preparing the STING agonist MSA-2-Mn according to claim 3, characterized in that: The mass of 4-(5,6-dimethoxybenzo[B]thiophen-2-yl)-4-oxobutyric acid in S1 is 58.8 mg, and the mass of sodium hydroxide is 8.0 mg.

5. The method for preparing the STING agonist MSA-2-Mn according to claim 3, characterized in that: The manganese chloride in S2 was weighed out to be 12.6 mg by mass.

6. The application of the STING agonist MSA-2-Mn in the preparation of antitumor drugs, characterized in that: The STING agonist MSA-2-Mn is the STING agonist MSA-2-Mn as described in claim 1.

7. The application of the STING agonist MSA-2-Mn according to claim 6 in the preparation of a tumor-treating drug, characterized in that: The MSA-2-Mn releases Mn and MSA-2 at the tumor site. Mn efficiently activates the cGAS-STING signaling pathway, while MSA-2 can selectively target tumor tissue, exhibiting a higher ability to activate the STING pathway.

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