A thio-carbonate based hydrogen sulfide donor and methods of making and using the same

Abstract

The present application relates to a kind of thio carbonates-based hydrogen sulfide donor and its preparation method and application.The thio carbonates-based hydrogen sulfide donor includes at least one alanine residue that can be broken by aminopeptidase N catalysis in its structure and at least one thiophenyl carbonate element or its derivative that can release carbonyl sulfide, also includes amino benzyl connecting element or its derivative that connects alanine residue and thiophenyl carbonate element.The hydrogen sulfide donor prepared by the present application can be triggered to release by aminopeptidase N specificity, realizes inflammation microenvironment specificity hydrogen sulfide delivery, compared with existing hydrogen sulfide donor, the hydrogen sulfide donor of the present application has greater advantage in the aspect of inflammation regulation.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to a hydrogen sulfide donor based on thiocarbonate, its preparation method, and its application. Background Technology

[0002] Hydrogen sulfide is an important gaseous signaling molecule that plays a key regulatory role in many physiological and pathological processes in the human body. Nature Reviews Drug Discovery , 2007, 6, 917. Currently, hydrogen sulfide-based therapies have achieved extensive preclinical research progress in areas including inflammation, tumors, tissue defects, and cardiovascular-related diseases ( , 2007, 6, 917). Bioactive Materials (2023, 19, 198.). However, the main factor limiting research on the physiological effects of hydrogen sulfide remains the difficulty in achieving controllable hydrogen sulfide delivery. Because hydrogen sulfide has a short half-life in the physiological environment, typically only a few seconds to a few minutes, direct inhalation of hydrogen sulfide gas makes it difficult to reach deep lesions, and the inhaled dose is difficult to control, posing significant safety risks during treatment. To address this issue, researchers have developed a series of hydrogen sulfide donor molecules that can sustainably release hydrogen sulfide in response to specific endogenous or exogenous stimuli. Biochemical Pharmacology (2018, 149, 110). However, most donor molecules are developed based on chemical reactions that produce hydrogen sulfide, and there are no specific rules to follow in their structural design, making it even more difficult to customize donor molecules for specific stimuli.

[0003] In 2016, researchers including Michael D. Pluth proposed a strategy using self-decomposing hydrogen sulfide donors. Journal of the American Chemical Society Based on this, a series of hydrogen sulfide donors based on thiocarbamates / thiocarbonates were constructed. The structural characteristic of these donor molecules is that after deprotection or other chemical reactions under external stimuli, a nucleophilic group is exposed, triggering a spontaneous 1,4- or 1,6-elimination reaction that cleaves the thiocarbonate or thiocarbamate, releasing one molecule of carbonyl sulfide, which is then converted into hydrogen sulfide by carbonic anhydrases widely present in the human body. To date, self-decomposing hydrogen sulfide donors responding to endogenous or exogenous stimuli, including pH, reactive oxygen species, nitroreductases, tetrazine, and light, have been reported. Accounts of Chemical Research (2019, 52, 2723). This strategy allows for the modulation of stimulus-response behavior by altering the protective matrix structure and has broad applicability.

[0004] The human body contains abundant proteases and peptidases, which can recognize specific amino acid sequences and hydrolyze amide bonds to exert their physiological functions. Furthermore, many proteases are highly expressed at pathological sites, participating in the formation of characteristic pathological microenvironments. Targeting the specific responses of proteases or peptidases highly expressed at pathological sites to specific amino acid sequences holds promise for constructing pathological microenvironment-responsive, self-decomposing hydrogen sulfide donors, enabling controllable hydrogen sulfide delivery and precise gas therapy. However, research on such protease or peptidase-responsive hydrogen sulfide donors based on specific polypeptide sequences is still in its early stages. In 2023, John B. Matson and Wang Yin et al. prepared a thiocarbonate-type hydrogen sulfide donor coupled with an alanine-alanine-asparagine sequence, which can be specifically cleaved by asparagine endopeptidases, triggering a self-decomposition reaction to release carbonyl sulfide, and enhancing the chemokinetic therapeutic effect by inhibiting the activity of catalase in tumor cells. AngewandteChemie International Edition (2023, 62,e202302303), but it increased the content of ROS and aggravated the level of inflammation.

[0005] Aminopeptidase N is a type II metalloproteinase belonging to the M1 zinc metallopeptidase family. It cleaves the N-terminal neutral amino acid residues (especially alanine) of various bioactive peptides to regulate their activity. Simultaneously, aminopeptidase N can also act as a cell surface receptor, participating in and regulating various physiological and pathological functions. In the immune system, aminopeptidase N can affect cell transport, antigen and inflammatory mediator processing, and can also regulate the activity of various hormones involved in inflammation by cleaving the N-terminus. Reports indicate that aminopeptidase N is highly expressed on the surface of monocytes, macrophages, and dendritic cells, mediating phagocytosis and is highly correlated with the activation and differentiation of immune cells. The Journal of Immunology (2020, 204, 3). Therefore, aminopeptidase N has been considered an important potential target for the treatment of inflammatory diseases. Given that the exact mechanism of action of hydrogen sulfide on the inflammatory response remains to be further investigated, there is an urgent need to develop donor molecules that can controllably deliver hydrogen sulfide to the inflammatory microenvironment. This would not only help elucidate the complex inflammatory regulatory role of hydrogen sulfide but also hold promise for developing novel hydrogen sulfide therapies for inflammatory diseases. However, no hydrogen sulfide donors that specifically respond to the inflammatory microenvironment have been reported to date. Utilizing the high expression of aminopeptidase N on the surface of immune cells, constructing self-degrading hydrogen sulfide donors responsive to aminopeptidase N may be a way to solve the above problems. Summary of the Invention

[0006] Based on the aforementioned shortcomings and deficiencies in the prior art, one of the objectives of this invention is to at least solve one or more of the aforementioned problems in the prior art. In other words, one of the objectives of this invention is to provide a hydrogen sulfide donor based on thiocarbonate, a method for its preparation, and its application that meets one or more of the aforementioned requirements.

[0007] To achieve the above object, the present application adopts the following technical scheme:

[0008] A thio-carbonate-based hydrogen sulfide donor, which comprises at least one alanine residue that can be catalytically broken by aminopeptidase N, at least one thio-carbonate phenyl ester element or its derivative that can release carbonyl sulfide, and a p-aminobenzyl connecting element or its derivative connecting the alanine residue and the thio-carbonate phenyl ester element.

[0009] Optionally, the structural formula of the hydrogen sulfide donor is:

[0010] Or

[0011] Wherein, R1 is selected from any one of CH3, F, Cl and Br, and R2 is selected from any one of CH3, F, Cl and Br.

[0012] The present application also provides a preparation method of the hydrogen sulfide donor as described in the above scheme, comprising the following steps:

[0013] (1) N - acid amine condensation reaction of t-butyloxycarbonyl-L-alanine and 4-aminobenzyl alcohol or its derivative to synthesize a primary intermediate product;

[0014] (2) condensation reaction of the primary intermediate product and thio-chloroformate phenyl ester or its derivative to synthesize a secondary intermediate product;

[0015] (3) removal of the t-butyloxycarbonyl protecting group from the secondary intermediate product to obtain the target product.

[0016] Optionally, the step (1) is subjected to acid amine condensation reaction under the action of a coupling agent 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline EEDQ, the reaction solvent is dichloromethane DCM, and the reaction time is 12-24 hours, and the reaction route is as follows:

[0017] .

[0018] Optionally, the amount of 4-aminobenzyl alcohol is 1.2-1.5 equivalents, and the amount of EEDQ is 1.5-2 equivalents, relative to N t-butyloxycarbonyl-L-alanine.

[0019] Optionally, the step (2) is subjected to condensation reaction under the catalysis of pyridine, the reaction solvent is dichloromethane, the reaction temperature is 0°C to room temperature, and the reaction time is 12-24 hours, and the reaction route is as follows:

[0020] .

[0021] Optionally, the amount of phenyl chlorothioformate is 1.5-2 equivalents, and the amount of pyridine is 2-3 equivalents, relative to the primary intermediate product.

[0022] Optionally, the reaction solvent of step (3) is trifluoroacetic acid (TFA) and dichloromethane (DCM), and the reaction time is 15-30 minutes, and the reaction route is as follows:

[0023] .

[0024] Optionally, in step (3), the target product is further purified by using a reversed-phase chromatographic column, and the gradient elution solvent is acetonitrile and water.

[0025] The application also provides the use of the hydrogen sulfide donor in the anti-inflammatory drug as described in the above scheme.

[0026] Compared with the prior art, the application has the following beneficial effects:

[0027] (1) The hydrogen sulfide donor prepared by the application can be specifically triggered to release by aminopeptidase N, and realizes specific hydrogen sulfide delivery in an inflammatory microenvironment, and compared with the prior hydrogen sulfide donor, the hydrogen sulfide donor of the application has greater advantages in the aspect of inflammation regulation;

[0028] (2) The hydrogen sulfide donor prepared by the application has more excellent anti-inflammatory effect than the general hydrogen sulfide donor, and compared with sodium sulfide, the pro-inflammatory index of the donor is significantly reduced under the same drug concentration for lipopolysaccharide (LPS)-induced macrophages;

[0029] (3) The preparation method of the application has the advantages of easy-to-obtain raw materials, short reaction route, no need for column chromatography purification of intermediate products, and simple operation. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 FIG. 1 is a schematic diagram of the preparation route of the hydrogen sulfide donor of Example 1 of the application;

[0031] Figure 2 FIG. 3 is a schematic diagram of the mechanism of the hydrogen sulfide donor of Example 1 of the application responding to aminopeptidase N to deliver hydrogen sulfide;

[0032] Figure 3 FIG. 4 (A) is the ultraviolet-visible absorption spectrum change of the donor after aminopeptidase N treatment, (B) is the hydrogen sulfide standard curve (determined by using sodium sulfide), (C) is the hydrogen sulfide release curve of the donor triggered by aminopeptidase N, and (D) is the relative response of the donor to aminopeptidase N and other enzymes, ions, amino acids, peptides, and active oxygen in the body fluid;

[0033] Figure 4Graphical comparison of the inhibitory effect of the hydrogen sulfide donor and sodium sulfide of Example 1 of the present application on the secretion of (A) nitric oxide, (B) tumor necrosis factor-alpha, and (C) interleukin-6 from LPS mouse macrophages. DETAILED DESCRIPTION

[0034] The present application will be described in detail below with specific examples. The following examples will help those skilled in the art to further understand the present application, but in no way limit the present application. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made. These are within the scope of the present application.

[0035] Unless otherwise specified, all chemicals purchased from commercial suppliers were used as received.

[0036] All solvents were of analytical grade.

[0037] The product was purified using a SHIMADZU LC-20AR semi-preparative liquid chromatograph using a reverse phase column.

[0038] Mass spectrometry data was determined using an Agilent 6230 time-of-flight liquid chromatography-mass spectrometry (TOF-LC / MS) instrument.

[0039] 1 H NMR data was determined using an Agilent 400 MHz NMR instrument using DMSO- d 6 as solvent.

[0040] The product was subjected to spectroscopic analysis using a SHIMADZU UV-2700 ultraviolet-visible spectrophotometer.

[0041] Standard methylene blue colorimetric method and Thermo Varioskan Flash multifunctional enzyme marker were used to determine the release of hydrogen sulfide from the donor.

[0042] Standard Griess method was used to detect the production of inflammatory marker nitric oxide.

[0043] Commercial enzyme-linked immunosorbent assay (ELISA) kit (Solarbio) was used to determine the secretion amount of pro-inflammatory cytokines.

[0044] Example 1:

[0045] As Figure 1 shown, the preparation method of the hydrogen sulfide donor of the present embodiment comprises the following steps:

[0046] (I) Synthesis of compound 2, the synthetic route of which is as follows:

[0047]

[0048] The specific synthesis steps are as follows: ... N -tert-Butoxycarbonyl-L-alanine (946 mg, 5 mmol), 4-aminobenzyl alcohol (924 mg, 7.5 mmol), and EEDQ (2473 mg, 10 mmol) were dissolved in 10 mL of dichloromethane and stirred at room temperature for 12 hours to carry out the acid-amine condensation reaction. The reaction solution was diluted with 20 mL of dichloromethane and washed with 0.5 M hydrochloric acid (30 mL × 3). The organic layer was separated, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to give the crude product 2 (1222 mg, 83% yield) as a white powder. This product can be used for subsequent reactions without further purification. ESI-MS: [M+Na] + The theoretical value is 317.1472, and the measured value is 317.1467.

[0049] (ii) The synthesis of compound 3, and its synthetic route is as follows:

[0050]

[0051] The specific synthetic steps were as follows: Compound 2 (1177 mg, 4 mmol) was dissolved in 20 mL of dichloromethane, and 632 μL of pyridine was added. The solution was cooled to 0°C in an ice bath, and phenyl thiochloroformate (800 μL, 6 mmol) was added dropwise with vigorous stirring. The reaction was stirred for 12 hours, and the mixture was gradually brought back to room temperature. The reaction solution was then washed with 0.5 M hydrochloric acid (30 mL × 3). The organic layer was separated, dried over anhydrous sodium sulfate, and the solvent was removed under reduced pressure to obtain the crude product of compound 3, which was a pale yellow oil. This product can be used in subsequent reactions without further purification. ESI-MS: [M + Na] + The theoretical value is 453.1455, and the measured value is 453.1348.

[0052] (III) The synthesis of compound 4 (hydrogen sulfide donor) is as follows:

[0053]

[0054] The specific synthetic steps were as follows: To remove the tert-butyloxycarbonyl protecting group, compound 3 was dissolved in 5 mL of a 1:1 mixture of trifluoroacetic acid and dichloromethane and stirred at room temperature for 15 minutes. The solvent was dried using an air pump to obtain the crude product of compound 4. The crude product was purified by semi-preparative high-performance liquid chromatography (HPLC) using a reverse-phase column with acetonitrile / deionized water as the gradient elution reagent and a detection wavelength of 220 nm. The purified compound 4 was a white powder solid (753 mg, 57%). ESI-MS: [M+H]+ The theoretical value is 331.1111, and the measured value is 331.1119. 1 H NMR (400 MHz, DMSO-) d 6) δ10.51 (s, 1H), δ8.27 (s, 2H), δ7.59-7.54 (d, 2H), δ7.47-7.41 (t, 2H), δ7.40-7.36 (d, 2H), δ 7.43-7.27 (t, 1H), δ7.24-7.17 (d, 2H), δ4.21 (s, 2H), δ4.05-3.96 (dd, 1H), δ1.50-1.39 (d, 3H).

[0055] like Figure 2 As shown, the mechanism by which hydrogen sulfide donors respond to aminopeptidase N to deliver hydrogen sulfide is as follows: hydrogen sulfide donors can specifically respond to the high expression of aminopeptidase N in the inflammatory microenvironment and undergo a self-decomposition reaction to release carbonyl sulfide, which is then converted into hydrogen sulfide under the action of carbonic anhydrase, exhibiting excellent anti-inflammatory effects at the cellular level.

[0056] The following analysis examines the hydrogen sulfide donor in this embodiment:

[0057] (I) Spectroscopic properties of hydrogen sulfide donors

[0058] Prepare a stock solution of hydrogen sulfide donor (10 mM in deionized water) and a stock solution of aminopeptidase N (1.9 mg / mL in deionized water), and dilute them to 3 mL of 1×PBS to achieve a final concentration of 50 μM for hydrogen sulfide donor and 1 μg / mL for aminopeptidase N. Incubate the above solutions in a shaker at 37°C. At set times (15, 30, 45, 60, 90, 120, 150, and 180 minutes), measure the absorption spectra in the range of 200–400 nm. The results are shown in [Figure number missing]. Figure 3 A (time increases sequentially along the arrow direction). As time progresses, the characteristic absorption at 249 nm gradually decreases, indicating that the donor is degraded by aminopeptidase N.

[0059] (II) Determination of hydrogen sulfide release from donors triggered by aminopeptidase N using the methylene blue method

[0060] 1. Plotting the standard curve

[0061] Prepare a 20 mM solution in 7.2 M hydrochloric acid. N,N 1-Dimethyl-p-phenylenediamine sulfate solution was prepared into a 30 mM ferric chloride solution in 1.2 M hydrochloric acid. A 10 mM sodium sulfide stock solution was prepared using PBS and diluted to 100, 50, 25, 12.5, 6.25, and 3.125 μM in 96-well plates, 100 μL per well. Subsequently, 25 μL of the solution was added to each well.N,N - 25 μL of dimethyl-p-phenylenediamine sulfate solution and 25 μL of ferric chloride solution, and the absorbance of the solution at 750 nm was measured after incubation at room temperature for 30 minutes. The standard curve was plotted with the concentration of sodium sulfide as the abscissa and the absorbance as the ordinate, and the regression equation was calculated by linear fitting using Origin software, as shown in Figure 3 B.

[0062] 2. Determination of hydrogen sulfide release curve

[0063] The mother liquor of each component was prepared using deionized water, including aminopeptidase N (1.9 mg / mL), carbonic anhydrase (10 mg / mL), and a donor (10 mM), and was diluted in 1x PBS to a final concentration of aminopeptidase N (1 μg / mL), carbonic anhydrase (25 μg / mL), and a donor (100 μM). The experiment was set up in triplicate, and the group without aminopeptidase N was used as a control. The above solution was incubated at 37°C on a shaking table, and 100 μL was taken at the set time (15, 30, 45, 60, 90, 120, 150, and 180 minutes) in a 96-well plate, and N, N - 25 μL of dimethyl-p-phenylenediamine sulfate solution and 25 μL of ferric chloride solution, and the absorbance of the solution at 750 nm was measured after incubation at room temperature for 30 minutes. The standard curve was plotted with the concentration of sodium sulfide as the abscissa and the absorbance as the ordinate, and the regression equation was calculated by linear fitting using Origin software, as shown in Figure 3 C. The results show that H2S is slowly released in the presence of aminopeptidase N and carbonic anhydrase, and reaches a maximum at 120 minutes. No release of hydrogen sulfide was detected in the absence of aminopeptidase N.

[0064] 3. Specific response of the donor to aminopeptidase N

[0065] The specificity of the donor to aminopeptidase N was verified, and enzymes, metal ions, amino acids, peptides, and active oxygen commonly found in the body fluid environment were selected as triggers. Deionized water was used to prepare the mother liquor of each component, including the donor 10 mM, carbonic anhydrase 10 mg / mL, enzymes (aminopeptidase N, aminopeptidase P, trypsin) 1 mg / mL, inorganic salts (sodium chloride, magnesium chloride, calcium chloride, ferric chloride, copper chloride) 100 mM, amino acids (L-glycine, L-arginine, L-cysteine) 100 mM, L-glutathione 100 mM, and hydrogen peroxide 100 mM. Each component mother liquor was dissolved in 1xPBS to a final concentration of 100 μM donor, 25 μg / mL carbonic anhydrase, 1 μg / mL trigger enzyme, 1 mM inorganic salt, 1 mM amino acid, 1 mM L-glutathione, and 1 mM hydrogen peroxide. Three groups were set up in parallel. The above solutions were incubated at 37°C for 1 h, 100 μL of each group was added to a 96-well plate, and the color developing agent was added and incubated for 30 min. The absorbance of the solution at 750 nm was measured using an enzyme marker, and the relative response factor A / A0 of each group was calculated (where A refers to the absorbance of the reaction solution, and A0 refers to the absorbance of the blank solution with only the trigger and carbonic anhydrase). The results are shown in Table 1. Figure 3 D. The results show that only when aminopeptidase N is present can the donor trigger the release of hydrogen sulfide, and it is not affected by other components in the body fluid.

[0066] (III) In vitro anti-inflammatory experiment of the donor

[0067] Mouse monocyte macrophage leukemia cells RAW264.7 were inoculated in a 24-well plate at a density of 10 5 cells / well. DMEM medium (containing 10% fetal bovine serum and 1% penicillin-streptomycin mixture) 500 μL was used to culture overnight to allow the cells to adhere. LPS (final concentration 0.1 μg / mL) was added to stimulate macrophages for 24 hours, and each well was replaced with fresh medium containing the donor or sodium sulfide (concentration 50, 100 μM) described in the application and continued to culture for 24 hours. The culture supernatant was centrifuged, and the contents of nitric oxide (NO) Figure 4 A) and pro-inflammatory cytokines (IL-1β, TNF-α) Figure 4 B, C) were detected using the standard Griess method and commercial ELISA kit (Solarbio).

[0068] The results show that the inflammation indicators after the hydrogen sulfide donor provided in the embodiment are significantly lower than the general donor sodium sulfide at the same administration concentration, and are almost reduced to the level of the control group without LPS stimulation, while the down-regulation of nitric oxide and inflammatory cytokines by sodium sulfide is not obvious. The above differences show that the inflammation microenvironment-controllable hydrogen sulfide slow release has a more significant in-vitro anti-inflammatory effect than the rapid burst release, further proving that the aminopeptidase N-responsive hydrogen sulfide donor provided in the application as an anti-inflammatory drug has great potential in the development of new hydrogen sulfide anti-inflammatory therapy.

[0069] Embodiment 2:

[0070] The hydrogen sulfide donor of the embodiment is different from that of embodiment 1 in that:

[0071] The number of alanine residues that can be catalytically cleaved by aminopeptidase N and the number of phenylthiocarbonates that can release carbonyl sulfide in the structure of the hydrogen sulfide donor of the embodiment can be designed to be multiple, which can be determined according to actual application requirements, and the effect of aminopeptidase N-specific response can also be achieved to achieve anti-inflammatory effect.

[0072] Other embodiments can refer to embodiment 1.

[0073] Embodiment 3:

[0074] The hydrogen sulfide donor of the embodiment is different from that of embodiment 1 in that:

[0075] The hydrogen sulfide donor of the embodiment is a derivative of the hydrogen sulfide donor of embodiment 1, and its structural formula is:

[0076]

[0077] wherein R1 is selected from any one of CH3, F, Cl and Br, and R2 is selected from any one of CH3, F, Cl and Br, which can be determined according to actual application requirements;

[0078] The raw materials of the hydrogen sulfide donor of the embodiment can be selected from derivatives of the corresponding raw materials, and the specific process steps can refer to embodiment 1, which will not be described here.

[0079] Since there are many embodiments of the present application, each component and process parameter can be determined according to actual needs within the corresponding range, and the experimental data of each embodiment is large and numerous, which is not suitable for listing and explaining one by one here. However, the content to be verified and the final conclusion obtained by each embodiment are similar. Therefore, the verification content of each embodiment will not be described one by one here, and only the above embodiments are used as representatives to illustrate the advantages of the present application.

[0080] The above merely describes the preferred embodiments and principles of the present application in detail, and for those skilled in the art, according to the ideas provided by the present application, there will be changes in the specific implementation manner, and these changes should also be considered as the protection scope of the present application.

Claims

1. A thio carbonic acid ester based hydrogen sulfide donor characterized in that, The structural formula is: or Wherein, R1 is selected from any one of CH3, F, Cl, Br, and R2 is selected from any one of CH3, F, Cl, Br.

2. The method for preparing a hydrogen sulfide donor according to claim 1, wherein The method comprises the following steps: (1) N - acid amine condensation of tert-butyloxycarbonyl-L-alanine with 4- aminobenzyl alcohol or derivatives thereof to synthesize the primary intermediate; (2) the primary intermediate product is condensed with phenyl chlorothioformate or its derivative to synthesize a secondary intermediate product; (3) the secondary intermediate product is deprotected from a tert-butyloxycarbonyl group to obtain the target product.

3. The preparation method according to claim 2, characterized in that, The step (1) is an acid-amine condensation reaction under the action of a coupling agent 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinoline EEDQ, the reaction solvent is dichloromethane DCM, and the reaction time is 12-24 hours, and the reaction route is as follows: 。 4. The production method according to claim 3, characterized by, with respect to N - t-butyloxycarbonyl-L-alanine, 4-aminobenzyl alcohol was used in an amount of 1.2 to 1.5 equivalents, and EEDQ was used in an amount of 1.5 to 2 equivalents.

5. The preparation method according to claim 3, characterized in that, The step (2) is a condensation reaction under the catalysis of pyridine, the reaction solvent is dichloromethane, the reaction temperature is 0-25°C, and the reaction time is 12-24 hours, and the reaction route is as follows: 。 6. The preparation method according to claim 5, characterized in that, The amount of phenyl chlorothioformate is 1.5-2 equivalents relative to the primary intermediate product, and the amount of pyridine is 2-3 equivalents.

7. The preparation method according to claim 6, characterized in that, The reaction solvent of the step (3) is trifluoroacetic acid TFA and dichloromethane DCM, and the reaction time is 15-30 minutes, and the reaction route is as follows: 。 8. The preparation method according to claim 6, characterized in that, In the step (3), the target product is also purified by using a reversed-phase chromatographic column, and the gradient elution solvent is acetonitrile and water.

9. Use of the hydrogen sulfide donor of claim 1 in the preparation of an anti-inflammatory drug.

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