An antioxidant and anti-inflammatory prodrug and its preparation and application

Abstract

The present invention relates to the field of pharmaceutical technology, and in particular to an antioxidant and anti-inflammatory prodrug, its preparation, and use. The antioxidant and anti-inflammatory prodrug is gallic acid-dexamethasone ester, obtained by ester-bonding gallic acid with antioxidant activity and dexamethasone with anti-inflammatory activity, with the structural formula shown in Formula I. The technical solution disclosed in the present invention not only provides a method for synthesizing the antioxidant and anti-inflammatory prodrug, but also provides a suspension eye drop formulation with significant anti-inflammatory and antioxidant activity. Specifically, the anti-inflammatory effects of dexamethasone and the antioxidant effects of gallic acid can synergistically treat systemic or localized inflammatory diseases, achieving a synergistic effect of increasing efficacy and reducing toxicity, providing a new approach for the treatment of inflammatory diseases. #imgabs0#

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to an antioxidant and anti-inflammatory prodrug and its preparation and application. Background Art

[0002] Inflammation is a common clinical pathological process. Most inflammatory conditions produce a persistent oxidative stress state during the onset of disease, leading to the production of large amounts of pro-inflammatory cytokines, exacerbating the inflammatory response and harming organs and tissues throughout the body. When non-infectious inflammatory diseases occur, such as iritis, keratitis, cyclitis, non-infectious uveitis, hepatitis, meningitis, nephritis, otitis media, and some autoimmune diseases, the severity of the disease is positively correlated with the body's oxidative stress state. Therefore, the design and development of a co-delivery system for drugs with anti-inflammatory and antioxidant effects can effectively control inflammation by both anti-inflammatory and oxidative stress reduction.

[0003] Gallic acid (GA), chemically known as 3,4,5-trihydroxybenzoic acid, is a phenolic compound naturally present in several plants, including mountain ash, fir, rice, guava, zygote, grape, and Virginia broom. GA is known for its antioxidant activity. In elastase-induced emphysema in rats, GA has been shown to inhibit inflammation and oxidative stress by regulating the Nrf2-HO-1-NF-xB signaling pathway. Furthermore, GA has been shown to have antioxidant and nephroprotective effects against paraquat-induced renal injury in male rats. However, due to its polyhydroxylated structure, GA has low intestinal permeability and is readily metabolized by metabolic enzymes in vivo. Previous studies have shown that only 0.012% of the initial oral GA dose can be detected in plasma. This extremely low bioavailability makes single-dose GA ineffective for the treatment of inflammatory diseases.

[0004] Dexamethasone (DEX) is a synthetic steroid widely used to treat a variety of inflammatory diseases due to its anti-inflammatory, anti-allergic, and immunosuppressive properties. However, high-dose or long-term use of dexamethasone can cause serious side effects, such as hypertension, peptic ulcers, hyperglycemia, and fluid and electrolyte imbalances. To address the shortcomings of these two antioxidant and anti-inflammatory drugs in clinical application, a novel drug delivery system is needed to co-deliver these two drugs, thereby increasing their efficacy and reducing their toxic side effects. Summary of the Invention

[0005] The present invention provides an antioxidant and anti-inflammatory prodrug as well as preparation and application thereof.

[0006] The present invention achieves the above-mentioned objectives through the following technical solutions:

[0007] An antioxidant and anti-inflammatory prodrug, wherein the antioxidant and anti-inflammatory prodrug is gallic acid with antioxidant activity and dexamethasone with anti-inflammatory activity connected by forming an ester bond to obtain gallic acid-dexamethasone ester, the structural formula of which is shown in Formula I:

[0008]

[0009] A method for preparing the antioxidant and anti-inflammatory prodrug, the synthesis route is as follows:

[0010]

[0011] Specific synthesis steps:

[0012] A. Protect the phenolic hydroxyl and carboxyl groups of gallic acid with protective groups, and then remove the protection of the carboxyl group by adding acetic acid-water;

[0013] B. Gallic acid protected with a protecting group is esterified with dexamethasone in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI), 4-dimethylamino-pyridine (DMAP) and 1-hydroxybenzotriazole (HOBT) to produce an intermediate;

[0014] C. The intermediate is deprotected in the presence of tetrabutylammonium fluoride (TBAF) / tetrahydrofuran (THF) to generate the final product, dexamethasone gallate (DG).

[0015] The protecting group in step A is selected from one of tert-butyldimethylsilyl, tert-butyldiphenylsilyl and triethylsilyl.

[0016] In the step A, the gallic acid solution and the protecting group solution are mixed by stirring at room temperature at a stirring speed of 500-800 rpm.

[0017] In the step B, the mass ratio of gallic acid, EDCI, DMAP, HOBT, and dexamethasone is 4:3-5:1-3:1-3:6.

[0018] The organic solvents in each step may be the same or different and may be selected from one or more of N,N-dimethylformamide, ethyl acetate, tetrahydrofuran and methanol.

[0019] Further,

[0020] S1, dissolving gallic acid (GA) in an organic solvent to form a gallic acid solution; dissolving tert-butyldimethylsilyl chloride in an organic solvent to form a tert-butyldimethylsilyl chloride solution, and dissolving tetrabutylammonium fluoride in an organic solvent to form a tetrabutylammonium fluoride solution;

[0021] S2, mixing the gallic acid solution and the tert-butyldimethylsilyl chloride solution with stirring for 24 hours, wherein the mass ratio of the gallic acid solution to the tert-butyldimethylsilyl chloride solution is 1:4-6. After the reaction is completed, the reaction solution is diluted with ethyl acetate and extracted with water; the organic layer is dried over sodium sulfate, and the organic solvent is removed by rotary evaporation to obtain a white solid product A;

[0022] S3. The obtained white solid A was dissolved in an organic solvent, and a mixture of acetic acid and water (3:1 (v / v)) was added. The reaction was stirred at room temperature for 24 h. After the reaction was completed, the reaction solution was poured into cold water, and the product was extracted with ethyl acetate. The organic matter was dried over Na2SO4 and concentrated in vacuo to obtain tert-butyldimethylsilane-protected gallic acid (TBS-GA);

[0023] S4. TBS-GA was dissolved in an organic solvent and cooled to 0°C. 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, 4-dimethylaminopyridine, and 1-hydroxybenzotriazole were then added in sequence and stirred for 2 hours to activate the carboxylic acid. After activation, dexamethasone was added and the mixture was stirred at room temperature for 24 hours. After the reaction, the organic solvent was removed to obtain a crude product, which was purified by column chromatography to obtain intermediate product B.

[0024] S5. The intermediate product B was dissolved in an organic solvent, and tetrabutylammonium fluoride solution was added to continue the reaction for 2 hours. After the reaction was completed, the reaction solution was diluted with ethyl acetate, washed with saturated brine, and purified by preparative liquid chromatography to obtain the final product DG.

[0025] In step S2, the mass ratio of gallic acid solution, tert-butyldimethylchlorosilane solution and imidazole is 1:4-6:3-5.

[0026] In step S3, the volume ratio of the white solid A to the acetic acid-water mixture is 1:1-3.

[0027] The prodrug is first frozen at -80°C, then freeze-dried using a vacuum freeze dryer, and then stored for a long time at -20°C in the absence of light and under nitrogen protection.

[0028] An application of the antioxidant and anti-inflammatory prodrug, and an application of the antioxidant and anti-inflammatory prodrug in the preparation of a drug for preventing or treating non-infectious inflammatory diseases.

[0029] A drug for preventing or treating inflammation, comprising the antioxidant and anti-inflammatory prodrug.

[0030] The dosage form of the medicine is suspension, tablet, capsule, suppository, solution, dripping pill, powder or injection emulsion.

[0031] The inflammation includes but is not limited to non-infectious inflammatory diseases such as non-infectious uveitis, iritis, keratitis, cyclitis, hepatitis, meningitis, nephritis, and otitis media.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. The present invention adopts a synergistic anti-inflammatory and antioxidant strategy, and utilizes an esterification reaction to couple dexamethasone and gallic acid to form dexamethasone gallate.

[0034] 2. When the dexamethasone gallate prodrug synthesized by the present invention acts on the site of inflammation, it can release the active ingredients dexamethasone and gallic acid through cleavage by esterases in the body. Dexamethasone binds to the glucocorticoid receptors at the site of inflammation, thereby exerting an anti-inflammatory effect. Gallic acid removes reactive oxygen species through its antioxidant effect, further reducing the damage caused by inflammation to the body. The synergistic effect of anti-inflammatory and antioxidant effects can reduce the dosage of glucocorticoid drugs such as dexamethasone in inflammatory diseases and reduce their adverse reactions. This improves the safety of the drug.

[0035] 3. The compound of the present invention utilizes an ester bond to link the anti-inflammatory drug dexamethasone with the antioxidant gallic acid, resulting in a dual-active pharmaceutical ingredient with anti-inflammatory and antioxidant properties. Furthermore, compared to the corresponding gallic acid used alone, the fat-soluble structure of dexamethasone in the compound enhances the cellular permeability of gallic acid, thereby increasing its effectiveness. Compared to the corresponding dexamethasone used alone, the compound achieves synergistic anti-inflammatory and antioxidant effects to treat inflammatory diseases, minimizes the dexamethasone dosage, and further improves the safety of the drug.

[0036] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 H NMR spectrum of dexamethasone gallate;

[0039] Figure 2 Mass spectrum of dexamethasone gallate;

[0040] Figure 3 This is a transmission electron microscope image of gallic acid-dexamethasone ester suspension;

[0041] Figure 4 The particle size distribution diagrams of dexamethasone suspension (DEX) and gallic acid-dexamethasone ester suspension (GD);

[0042] Figure 5 The in vitro release curves of dexamethasone suspension (DEX) and gallic acid-dexamethasone ester suspension (GD);

[0043] Figure 6 This is a test chart of the DPPH free radical scavenging ability of dexamethasone gallate;

[0044] Figure 7 This is a test chart of the ABTS free radical scavenging ability of dexamethasone gallate;

[0045] Figure 8 This is a test chart of the HO· free radical scavenging ability of dexamethasone gallate;

[0046] Figure 9 This is a test diagram of the NO scavenging ability of gallic acid-dexamethasone ester;

[0047] Figure 10 This is the anterior segment scoring diagram (slit lamp microscopy) of rats with non-infectious uveitis treated with gallic acid-dexamethasone ester suspension;

[0048] Figure 11 This is the change of intraocular pressure in rats after non-infectious uveitis was treated with gallic acid-dexamethasone ester suspension eye drops;

[0049] Figure 12 This is the H&E section scoring diagram of the anterior segment iris of rats with non-infectious uveitis treated with gallic acid-dexamethasone ester suspension eye drops;

[0050] Figure 13 This is the H&E section scoring diagram of the anterior segment ciliary body of rats with non-infectious uveitis treated with gallic acid-dexamethasone ester suspension eye drops;

[0051] Figure 14 This is the H&E section scoring diagram of the posterior segment optic disc and retina of rats with non-infectious uveitis treated with gallic acid-dexamethasone ester suspension eye drops;

[0052] in, Figure 10 and Figure 12-14In the table, significance compared with the positive group (EAU group) is indicated by *, * represents p < 0.05, ** represents p < 0.01, *** represents p < 0.001, and **** represents p < 0.0001. DETAILED DESCRIPTION

[0053] The following examples are intended to further illustrate the present invention, but are not intended to limit the present invention in any way.

[0054] Example 1 Synthesis of Gallic Acid-Dexamethasone Ester.

[0055] Gallic acid (2 g, 11.76 mmol) was weighed and dissolved in N,N-dimethylformamide to form a gallic acid solution; tert-butyldimethylsilyl chloride (TBSCl, 10 g, 66.34 mmol) was weighed and dissolved in N,N-dimethylformamide to form a tert-butyldimethylsilyl chloride solution. The gallic acid solution, tert-butyldimethylsilyl chloride solution and imidazole (IMD, 8 g, 117.51 ​​mmol) were mixed and stirred for 24 h. After the reaction was completed, the reaction solution was diluted with ethyl acetate (160 mL) and washed with water (6 × 40 mL) extraction; the organic layer was dried over sodium sulfate, and the organic solvent was rotary evaporated to obtain a white solid product A (6.83 g, yield 93%); the obtained white solid A was dissolved in tetrahydrofuran, and a mixture of acetic acid and water (3:1 (v / v)) was added, and the reaction was stirred at room temperature for 24 hours. After the reaction, the reaction solution was poured into cold water, and the product was extracted with ethyl acetate. The organic matter was dried over Na2SO4 and concentrated in vacuo to obtain tert-butyldimethylsilane-protected gallic acid (TBS-GA) (1.54 g, 94%);

[0056] TBS-GA (615.5 mg, 1.2 mmol) was dissolved in dichloromethane and cooled to 0°C. EDCI (690.12 mg, 3.6 mmol), DMAP (457.67 mg, 3.6 mmol), and HOBT (486.43 mg, 3.6 mmol) were then added sequentially and stirred for 2 hours to activate the carboxylic acid. After activation, dexamethasone (785 mg, 2.0 mmol) was added and stirred at room temperature for 24 hours. After completion of the reaction, the organic solvent was removed to obtain a crude product, which was purified by column chromatography to obtain intermediate B (798.15 mg, 75%).

[0057] The intermediate product B (300 mg, 0.338 mmol) was weighed and dissolved in an organic solvent. Tetrabutylammonium fluoride solution was added and the reaction was continued for 2 h. After the reaction was completed, the reaction solution was diluted with ethyl acetate and washed with saturated brine 2-4 times. The final product, dexamethasone gallate (163.37 mg, 89%), was purified by preparative liquid chromatography. The structure of dexamethasone gallate was confirmed by nuclear magnetic resonance and mass spectrometry. Figure 1 and Figure 2 shown.

[0058] Figure 1 The NMR spectrum of gallic acid-dexamethasone ester shows that 7.43 ppm corresponds to H-1 on the dexamethasone molecule, 7.09 ppm corresponds to H-3' and H-7' on the gallic acid molecule, 6.29 ppm corresponds to H-2 on the dexamethasone molecule, 6.08 ppm corresponds to H-4 on the dexamethasone molecule, 5.11 ppm corresponds to H-21 on the dexamethasone molecule, 4.29 ppm corresponds to H-11 on the dexamethasone molecule, 3.09-3.00 ppm corresponds to H-16 on the dexamethasone molecule, 2.73 ppm corresponds to Ha-6 on the dexamethasone molecule, 2.48 ppm corresponds to H-8 on the dexamethasone molecule, and 2.40 ppm corresponds to H-9 on the dexamethasone molecule. 1.60 ppm corresponds to Hb-19 on the dexamethasone molecule, 1.54 ppm corresponds to Hb-7 on the dexamethasone molecule, 1.21 ppm corresponds to Hb-15 on the dexamethasone molecule, 1.05 ppm corresponds to H-18 on the dexamethasone molecule, and 0.88 ppm corresponds to H-22 on the dexamethasone molecule.

[0059] Figure 2 The mass spectrometry results of gallic acid-dexamethasone ester show that the peak at 545.2186 is [M+H] and the peak at 567.1993 is [M+Na]. The molecular formula is C 29 H 33 FO9.

[0060] Example 2 Preparation of Dexamethasone or Gallic Acid-Dexamethasone Ester Suspension

[0061] Table 1: Components and proportions of dexamethasone suspension

[0062] Components Quantity (% w / v) Dexamethasone 1.50 γ-cyclodextrin 14.00 Edetate disodium 0.10 Poloxamer 407 2.50 Sodium chloride 0.57 Sodium thiosulfate 0.3 Water for injection Full amount 100.00

[0063] Table 2: Components and proportions of gallic acid-dexamethasone ester suspension

[0064] Components Quantity (% w / v) Gallic acid-dexamethasone ester obtained in the above embodiment 1.50 γ-cyclodextrin 14.00 Edetate disodium 0.10 Poloxamer 407 2.50 Sodium chloride 0.57 Sodium thiosulfate 0.3 Water for injection Full amount 100.00

[0065] Prepare the suspension as follows:

[0066] Cyclodextrin and poloxamer 407 were added to water to form a suspension, and dexamethasone was added to the suspension. The mixture was stirred at 95°C for 15 minutes until the dexamethasone and cyclodextrin were substantially dissolved to form a colorless, clear solution. The resulting solution was cooled to 25°C over 15 minutes while stirring to obtain a coarse suspension of a solid complex of dexamethasone and cyclodextrin. Finally, a certain amount of 0.5 mm zirconium oxide grinding beads was added, and the grinding tube was placed in a grinder. The grinding parameters were adjusted to obtain a dexamethasone suspension (DEX). Simultaneously, a gallic acid-dexamethasone ester suspension (GD) was prepared according to the above table and preparation process.

[0067] The transmission electron microscope photograph of the obtained gallic acid-dexamethasone ester suspension is as follows: Figure 3 The particle size of the suspension was measured by laser diffraction, and the particle size distribution was shown as follows. Figure 4 As shown. Figure 4 It can be seen that the particle sizes of DEX and GD are both in the micron order, which indicates that the dispersion state of dexamethasone and gallic acid-dexamethasone ester in water is in the form of suspension, and after gallic acid and dexamethasone are prepared into a prodrug, the particle size of the suspension of the prodrug is slightly smaller than that of DEX.

[0068] Example 3 In vitro release curve of dexamethasone or gallic acid-dexamethasone ester suspension

[0069] Dynamic dialysis was used to evaluate the release of gallic acid-dexamethasone ester suspension in artificial tears (ATF). 0.678 g NaCl, 0.138 g KCl, 0.0063 g CaCl2 and 0.218 g NaHCO3 were dissolved in 100 mL of pure water to prepare ATF. 0.5 mL of the gallic acid-dexamethasone ester suspension or dexamethasone suspension prepared in the above example was placed in a dialysis bag with a molecular weight of 1 KDa, stirred at 34.5 ± 0.5 ° C, and immersed in 375 mL ATF. Samples (4 ml) were collected at predetermined time points and replaced with fresh ATF at the same temperature. The concentrations of dexamethasone and gallic acid-dexamethasone ester were determined by UV-visible spectrophotometry, and their in vitro release curves were shown in Figure 3. Figure 5 shown.

[0070] Depend on Figure 5 As can be seen, the release rate of the gallic acid-dexamethasone ester suspension eye drops was lower than that of the dexamethasone suspension eye drops. By 12 hours, the cumulative release of dexamethasone reached approximately 90%, while the gallic acid-dexamethasone ester had only released approximately 60%. The complete release of gallic acid and dexamethasone from the formulation indicated that the formation of CD aggregates allowed for the gradual dissociation into nanoparticles and further release from the inclusion complex. The prolonged release time reduced rapid drug clearance due to tear turnover, thereby retaining the drug on the ocular surface.

[0071] Example 4 In vitro DPPH free radical scavenging ability test of gallic acid-dexamethasone ester suspension

[0072] The DPPH free radical scavenging activity assay was performed as follows: different concentrations of dexamethasone-gallate methanol solutions (12.5, 25, 50, 100, 200, and 400 μg / mL) were mixed with a 2 mM DPPH free radical solution for 30 minutes. The absorbance was measured at 517 nm, and the DPPH free radical inhibition percentage (I%) was calculated as follows:

[0073] I%=(A blank -A sample ) / A sample ×100%

[0074] Among them A blank is the absorbance of the control reaction (containing all reagents except the test compound), A sample is the absorbance of the test compound. Figure 6 shown.

[0075] Depend on Figure 6 It can be seen that with the increase of gallic acid-dexamethasone ester concentration, the corresponding free radicals were rapidly scavenged. Under the treatment of 25μg / mL DG, the DPPH· free radical scavenging rate reached about 80%, showing the highest scavenging ability.

[0076] Example 5 In vitro ABTS free radical scavenging ability test of gallic acid-dexamethasone ester

[0077] The specific operation of the ABTS free radical scavenging ability determination is as follows: dexamethasone gallate methanol solution of different concentrations is mixed with ABTS·free radical working solution at room temperature for 6 minutes, the absorbance is measured at 734 nm, and the ABTS·free radical inhibition rate is calculated according to the above formula.

[0078] I%=(A blank -A sample ) / A sample ×100%

[0079] Among them A blank is the absorbance of the control reaction (containing all reagents except the test compound), A sample is the absorbance of the test compound. Figure 7 shown.

[0080] Depend on Figure 7It can be seen that when the concentration of gallic acid-dexamethasone ester reaches 50μg / mL, its ABTS· free radical scavenging rate can reach nearly 90%. Among a series of polyphenol compounds, DG showed excellent free radical scavenging ability.

[0081] Example 6 Test of the ability of gallic acid-dexamethasone ester to scavenge hydroxyl radicals in vitro

[0082] The specific operation of the hydroxyl radical scavenging ability test is as follows: a mixture of 1,1-phenanthroline methanol solution (1,1-phenanthroline concentration is 0.99 mg / mL, 30 μL), PBS buffer (80 μL) and different concentrations of dexamethasone gallate methanol solution (200 μL) was prepared, ferrous sulfate and 0.1% hydrogen peroxide solution were added, and the mixture was incubated at 37°C for 30 minutes. The absorbance was measured at 510 nm, and the hydroxyl radical inhibition rate was calculated:

[0083] I%=(A o +A j -A i ) / A0×100%

[0084] Where A0 is the absorbance of the negative control reaction (containing methanol solution without test compound), A j is the absorbance of the positive control reaction (containing vitamin C aqueous solution without test compound), A i is the absorbance of the test compound. Figure 8 shown.

[0085] Depend on Figure 8 As can be seen, when the concentration of gallic acid-dexamethasone ester reaches 100 μg / mL, the scavenging rate of ·OH free radicals is close to 40%, but when the concentration reaches 400 μg / mL, the scavenging rate of ·OH free radicals is close to 80%. The above phenomenon shows that gallic acid-dexamethasone ester has excellent scavenging ability for ·OH free radicals. Based on its strong scavenging ability for the three free radicals, it can be inferred that gallic acid-dexamethasone ester has strong antioxidant capacity.

[0086] Example 7 In vitro NO scavenging ability test of gallic acid-dexamethasone ester

[0087] The NO scavenging capacity assay was performed by mixing different concentrations of gallic acid-dexamethasone ester methanol solution with sodium nitroprusside (7.5 mM) (volume ratio: 9:1) and incubating at 25°C for 2 hours. NO scavenging capacity was measured using Griess reagent at 540 nm. The NO scavenging rate was calculated as follows:

[0088] NO clearance rate (%) = (1-A sample / A blank )×100%

[0089] Among them A blank is the absorbance of the control reaction (containing all reagents except the test compound), A sample is the absorbance of the test compound. Figure 9 shown.

[0090] Depend on Figure 9 As can be seen, at a concentration of 100 μg / ml, dexamethasone gallate eliminated over 30% of NO. NO is a reactive nitrogen species (RNS), and therefore, reactive oxygen species (ROS) and RNS generated by oxidative stress are considered the initial pathological events leading to the uveitis-induced damage observed during the amplification phase. Studies have shown that reducing NO effectively alleviates uveitis inflammation in rats. Dexamethasone gallate not only possesses anti-inflammatory capabilities but also antioxidant properties, potentially reducing ROS by eliminating free radicals and NO, which may be more effective in treating uveitis.

[0091] Example 8: Verification of the efficacy of gallic acid-dexamethasone ester suspension in treating non-infectious uveitis in rats

[0092] A non-infectious uveitis model was established in female Lewis rats (6-8 weeks old, 160-180 g). Bovine IRBP R16 was emulsified in complete Freund's adjuvant (CFA) containing 2 mg / mL of Mycobacterium tuberculosis H37RA. On day 0, 125 μL of the antigen emulsion was subcutaneously injected into the hind footpads of the rats. On the 6th day after immunization, the rats were randomly divided into 5 groups (n=3 in each group): (1) Normal group: non-immunized group, no drug administration; (2) EAU group: immunized rats without treatment; (3) DEX group: rats were given dexamethasone suspension eye drops (15 mg / mL, 10 μL / eye, the ingredients and preparation method are as described in Example 2) 3 times a day; (4) Low dosage group: rats were given gallic acid-dexamethasone suspension eye drops (10 mg / mL, 10 μL / eye, the ingredients and preparation method are as described in Example 2) 3 times a day; (5) High dosage group: rats were given gallic acid-dexamethasone suspension eye drops (10 mg / mL, 10 μL / eye, the ingredients and preparation method are as described in Example 2) 6 times a day. Clinical signs of ocular inflammation were examined and scored using a slit lamp biomicroscope every 2 days. Figure 10 To exclude any side effects of dexamethasone eye drops, the changes in intraocular pressure (IOP) of each group were monitored. The results are shown in Figure 11 shown.

[0093] from Figure 10It can be concluded that on the 14th day after immunization, the EAU group showed obvious clinical symptoms of uveitis (i.e., pupil occlusion and ptosis), while the drug-treated group showed almost no inflammatory response.

[0094] from Figure 11 It can be concluded that after administration, the IOP of the dexamethasone group increased significantly; in contrast, the IOP of the low-dose and high-dose gallic acid-dexamethasone ester groups decreased more. These results indicate that gallic acid-dexamethasone ester suspension can alleviate the adverse reactions caused by dexamethasone and has a positive therapeutic effect on non-infectious uveitis in rats.

[0095] Example 9 Scoring of Dexamethasone Gallate Suspension in Sections of the Anterior and Posterior Segments of the Eyes in Rats with Non-infectious Uveitis

[0096] On the 14th day after immunization, rats in each group were killed and their eyeballs were removed for histopathological analysis. After dehydration, the fixed samples were embedded in paraffin, sliced ​​into 5 μm thick slices, and stained with hematoxylin and eosin (H&E). Pathologists evaluated the inflammatory response and retinal damage. On the 14th day after immunization, the iris, ciliary body, and retina of each group were histopathologically sectioned and scored. The results of H&E section scoring of the anterior and posterior segments of the eyes of rats with non-infectious uveitis treated with dexamethasone gallate suspension are shown in Figure 2. Figure 12-14 shown.

[0097] from Figure 12 and 13 It can be seen that in the anterior segment of the rat eye, a large number of inflammatory cells infiltrated the iris and ciliary body in the EAU group, while the influx of inflammatory cells was significantly reduced in the DEX, low-dose group and high-dose group. Figure 14 It can be concluded that in the posterior segment of the rat eye, the EAU group showed accumulation of large amounts of inflammatory exudates in the retina and optic disc, accompanied by severe damage to the retinal structure (i.e., retinal wrinkles). Dexamethasone, low-dose dexamethasone gallate, and high-dose dexamethasone gallate groups all reduced inflammatory responses in the retina and optic disc.

Claims

1. An antioxidant and anti-inflammatory prodrug, characterized in that The antioxidant and anti-inflammatory prodrug is gallic acid with antioxidant activity and dexamethasone with anti-inflammatory activity, which are connected by forming an ester bond to obtain gallic acid-dexamethasone ester, and its structural formula is shown in Formula I:

2. A method for preparing the antioxidant and anti-inflammatory prodrug according to claim 1, characterized in that: The synthetic route is as follows:

3. The method for preparing the antioxidant and anti-inflammatory prodrug according to claim 2, characterized in that: The synthesis steps include: A. Protect the phenolic hydroxyl and carboxyl groups of gallic acid with protective groups, and then remove the protection of the carboxyl group by adding acetic acid-water; B. Gallic acid protected with a protecting group is esterified with dexamethasone in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCI), 4-dimethylamino-pyridine (DMAP) and 1-hydroxybenzotriazole (HOBT) to produce an intermediate; C. The intermediate is deprotected in the presence of tetrabutylammonium fluoride (TBAF) / tetrahydrofuran (THF) to generate the final product, gallic acid-dexamethasone ester.

4. The method for preparing the antioxidant and anti-inflammatory prodrug according to claim 3, characterized in that: The protecting group in step A is selected from one of tert-butyldimethylsilyl, tert-butyldiphenylsilyl and triethylsilyl.

5. The method for preparing the antioxidant and anti-inflammatory prodrug according to claim 3, characterized in that: In the step A, the gallic acid solution and the protecting group solution are mixed by stirring at room temperature at a stirring speed of 500-800 rpm.

6. The method for preparing the antioxidant and anti-inflammatory prodrug according to claim 3, characterized in that: In the step B, the mass ratio of gallic acid, EDCI, DMAP, HOBT, and dexamethasone is 4:3-5:1-3:1-3:

6.

7. The method for preparing the antioxidant and anti-inflammatory prodrug according to claim 3, characterized in that: The organic solvents in each step may be the same or different and may be selected from one or more of N,N-dimethylformamide, ethyl acetate, tetrahydrofuran and methanol.

8. Use of the antioxidant and anti-inflammatory prodrug according to claim 1, characterized in that: Application of the antioxidant and anti-inflammatory prodrug in the preparation of drugs for preventing or treating non-infectious inflammatory diseases.

9. A drug for preventing or treating inflammation, characterized in that: The medicine contains the antioxidant and anti-inflammatory prodrug according to claim 1.

10. The anti-inflammatory drug according to claim 9, characterized in that: The dosage form of the medicine is suspension, tablet, capsule, suppository, solution, dripping pill, powder or injection emulsion.

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