Application of natural derivative in preparation of medicine for treating nephropathy and / or renal fibrosis

Abstract

The invention relates to the technical field of biological medicines, and discloses an application of a hypoxanthine derivative in preparation of a medicine for treating renal fibrosis and / or nephropathy, and the pharmacological activity of the hypoxanthine derivative subjected to structure modification and transformation is detected to treat renal fibrosis and / or nephropathy. The pharmacological activity of the compound is tested in an animal disease model, and the data of the activity of preventing and treating renal fibrosis and / or nephropathy is provided, which proves that the compound has good activity, and the effect is obviously superior to that of clinically common positive drugs nintedanib and losartan; the effect is obviously superior to those of hypoxanthine derivatives A, B and C and other hypoxanthine derivatives in the prior art. The hypoxanthine derivative disclosed by the invention can provide a novel skeleton for screening a novel compound for preparing a medicine for treating renal fibrosis and / or nephropathy, and lays a theoretical foundation for developing a novel lead compound.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, and in particular to the use of a hypoxanthine derivative in the preparation of drugs for treating kidney disease and / or renal fibrosis. Background Technology

[0002] Nephropathy is a common disease of the urinary system, caused by various factors such as diabetic nephropathy, glomerulonephritis, and hypertensive glomerular arteriosclerosis, resulting in structural and functional defects in the kidneys. Currently, there are no effective treatments for nephropathy; it is a relatively common and difficult-to-treat disease and has become a global public health concern.

[0003] Renal fibrosis is an important pathological process in the progression of various kidney diseases to chronic kidney disease. Renal fibrosis involves the damage of nephrons, the excessive proliferation of fibroblasts in the interstitium, the transformation of renal tubular epithelial cells into myofibroblasts, the excessive deposition of extracellular matrix in the renal interstitium, the infiltration of various inflammatory cells, and the atrophy of renal tubules, ultimately leading to the complete loss of renal function.

[0004] Renal fibrosis is mainly manifested as glomerular sclerosis and tubulointerstitial fibrosis. The main pathological changes of renal fibrosis are excessive deposition of extracellular matrix, infiltration of inflammatory cells, progressive reduction of nephrons, which leads to the destruction of normal nephron structure and loss of renal function [1]. When renal tubular epithelial cells are damaged, apoptosis and epithelial cell phenotypic transformation, namely epithelial-mesenchymal transition, occur, which produces a large number of growth factors, such as TGF, FGFs, PDGF, etc. Fibroblasts respond to these factors and differentiate into myofibroblasts, leading to renal tubular atrophy and excessive accumulation of extracellular matrix around the tubules [2]. Excessive accumulation of extracellular matrix in the interstitium increases the distance between capillaries and adjacent nephrons, and the microvessels around the tubules become sparse, resulting in insufficient oxygen and energy supply to renal tubular epithelial cells, cell dysfunction, further aggravating hypoxia, inducing damage and inflammatory response, forming a vicious cycle, thereby aggravating fibrosis [3].

[0005] Renal fibrosis is an irreversible process, eventually leading to kidney failure and severely impacting patients' lives. China has over 100 million kidney disease patients, including over 1.5 million with end-stage renal disease, and this number is increasing annually, placing a significant economic burden on my country's healthcare system. Currently, the main drugs used to treat kidney disease include RASS, SARA, and SGLT2 inhibitors; however, the global standardized mortality rate for kidney disease has only decreased by 2.8% over 30 years, indicating a very limited improvement. For example, losartan, an angiotensin II receptor antagonist (AIIA), is widely used clinically to treat kidney disease, but it lacks anti-fibrotic activity; it only improves symptoms and cannot halt disease progression.

[0006] Currently, only two anti-fibrotic drugs are used clinically: nintedanib and pirfenidone. However, due to the different pathogenesis of fibrosis in different organs, their efficacy in treating kidney disease and / or renal fibrosis is not good. The FDA has only approved their clinical indication for pulmonary fibrosis. Pulmonary fibrosis is caused by type II epithelial cells secreting pro-fibrotic factors after injury, mediating epithelial-mesenchymal transition, fibroblast differentiation into myofibroblasts, secretion of collagen, etc., resulting in excessive deposition of extracellular matrix, ultimately leading to pulmonary fibrosis and permanent loss of lung function.

[0007] Nintedanib has been approved for indications including idiopathic pulmonary fibrosis (IPF), non-small cell lung cancer (NSCLC), systemic sclerosis-associated interstitial lung disease (SSc-ILD), and progressive fibrotic interstitial lung disease (PF-ILD). Nintedanib is attempting to expand its indications to include endometrial fibrosis in a Phase II / III clinical trial (NCT05635071), but this has not yet been approved. Pirfenidone has been approved for indications including idiopathic pulmonary fibrosis (IPF). Pirfenidone is attempting to expand its indications to include liver fibrosis (NCT02161952), renal fibrosis (NCT04258397), post-myocardial infarction myocardial fibrosis (NCT05531955), and multiple sclerosis (NCT03109288) in a Phase I / II clinical trial, but none of these have yet been approved.

[0008] Currently, there are no drugs to treat renal fibrosis. Research on drugs targeting kidney disease and renal fibrosis with novel mechanisms and targets has become a hot topic, with significant social implications and value. Therefore, finding a drug that can prevent and treat kidney disease and / or renal fibrosis is crucial for the prevention and treatment of kidney disease.

[0009] Hypoxanthine, also known as 6-hydroxypurine, is a naturally occurring purine compound and a precursor for the synthesis of purine nucleotides in nucleic acids. Currently, there are no reports of hypoxanthine derivatives blocking the progression of kidney disease and / or renal fibrosis or reversing pathological damage. We have developed a series of hypoxanthine derivatives that can effectively improve kidney disease and / or renal fibrosis. Summary of the Invention

[0010] The purpose of this invention is to propose the application of a hypoxanthine derivative in the preparation of drugs for treating kidney disease and / or renal fibrosis, thereby accelerating the development of new drugs for treating kidney disease and / or renal fibrosis. The numerous technical effects of the preferred embodiment of this invention are detailed below.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] The first aspect of this invention relates to the use of hypoxanthin derivatives in the preparation of drugs for treating nephropathy and / or renal fibrosis, wherein the hypoxanthin derivatives have activity for treating nephropathy and / or renal fibrosis, and wherein the hypoxanthin derivatives have one of the following structures:

[0013]

[0014] in:

[0015] R1 can be any of O, N, C, S or = O;

[0016] R2, R3, and R4 can be chosen as H and C1-C, respectively. 18 Alkyl or halogen-substituted C1-C 18 Alkyl, trifluoromethyl, sulfonyl, sulfonamide, sulfinyl, amino acid, 2-[bis(neopentyloxy)methoxy]phosphonomethoxyethyl, C1-C 18 Fatty acid group, C3-C 12 Heterocyclic groups, C1-C 18 Fatty acids; or C1-C atoms in which R2, R3, and R4 are optionally substituted with oxygen, sulfur, or nitrogen atoms. 18 The alkyl or fatty acid group; when R3 or R4 is substituted, the double bond is attached to the unsubstituted N position, and when all are substituted, there is no double bond.

[0017] The second aspect of this invention relates to compounds having the following structure:

[0018]

[0019] in:

[0020] R1 can be any of O, N, C, S or = O;

[0021] R2, R3, and R4 can be chosen as H and C1-C, respectively. 18 Alkyl or halogen-substituted C1-C 18 Alkyl, trifluoromethyl, sulfonyl, sulfonamide, sulfinyl, amino acid, 2-[bis(neopentyloxy)methoxy]phosphonomethoxyethyl, C1-C 18 Fatty acid group, C3-C 12 Heterocyclic groups, C1-C 18 Fatty acids; or C1-C atoms in which R2, R3, and R4 are optionally substituted with oxygen, sulfur, or nitrogen atoms. 18 The alkyl or fatty acid group; when R3 or R4 is substituted, the double bond is attached to the unsubstituted N position, and when all are substituted, there is no double bond.

[0022] According to a preferred embodiment, the compound is selected from the group consisting of:

[0023]

[0024] A third aspect of the present invention relates to pharmaceutical compositions comprising the compounds of the present invention or pharmaceutically acceptable salts thereof.

[0025] According to a preferred embodiment, the pharmaceutical composition further comprises pharmaceutically acceptable excipients or auxiliary ingredients.

[0026] According to a preferred embodiment, the pharmaceutical composition is an oral formulation, an injectable formulation, or a nasal mucosal administration formulation.

[0027] The fourth aspect of the present invention relates to a method for treating kidney disease and / or renal fibrosis by administering an effective amount of the compound of the present invention or a pharmaceutically acceptable salt thereof, or a pharmaceutical composition of the present invention, to an individual in need.

[0028] According to a preferred embodiment, the drug for treating kidney disease and / or renal fibrosis is a formulation prepared by adding pharmaceutically acceptable excipients or auxiliary ingredients, with hypoxanthine derivatives or their salts as the active ingredient.

[0029] According to a preferred embodiment, the formulation is an oral formulation, an injectable formulation, or a nasal mucosal administration formulation.

[0030] According to a preferred embodiment, the kidney disease and / or renal fibrosis refers to structural and functional disorders of the kidney caused by various reasons, wherein the kidney disease includes one or more of idiopathic kidney disease and secondary kidney disease, and the renal fibrosis includes one or more of idiopathic renal fibrosis and secondary renal fibrosis.

[0031] Terminology definition:

[0032] The compounds and derivatives provided by this invention can be named according to the IUPAC (International Union of Pure and Applied Chemistry) or CAS (Chemical Abstracts Service, Columbus, OH) nomenclature systems.

[0033] The term "alkyl" refers to a straight-chain or branched saturated hydrocarbon group. Examples of C1 to C3 alkyl groups include methyl (C1), ethyl (C2), n-propyl (C3), and isopropyl (C3).

[0034] The term "pharmaceutically acceptable" means that a carrier, delivery substance, diluent, excipient, and / or the salt formed therefrom is generally chemically or physically compatible with other components constituting a drug dosage form and physiologically compatible with receptors.

[0035] The term "pharmaceutically acceptable salt" refers to acidic and / or basic salts formed by the compounds of this invention with inorganic and / or organic acids and bases, including zwitterionic salts (internal salts) and quaternary ammonium salts, such as alkylammonium salts. These salts can be obtained directly during the final separation and purification of the compounds. Alternatively, they can be obtained by mixing the aforementioned compounds with appropriate (e.g., equimolar) amounts of an acid or base. These salts may form precipitates in solution and be collected by filtration, or be recovered after solvent evaporation, or be prepared by freeze-drying after reaction in an aqueous medium. The salts described in this invention can be hydrochlorides, sulfates, citrates, benzenesulfonates, hydrobromides, hydrofluoric acids, phosphates, acetates, propionates, succinates, oxalates, malates, succinates, fumarates, maleates, tartrates, or trifluoroacetates of the compounds.

[0036] There are no particular limitations on the administration of the compounds or pharmaceutical compositions of the present invention. Representative administration methods include (but are not limited to): oral, parenteral (intravenous, intramuscular or subcutaneous) and topical administration.

[0037] Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In these solid dosage forms, the active compound is mixed with at least one conventional inert excipient (or carrier), such as sodium citrate or dicalcium phosphate, or with: (a) fillers or solubilizers, such as starch, lactose, sucrose, glucose, mannitol, and silica; (b) binders, such as hydroxymethyl cellulose, alginate, gelatin, polyvinylpyrrolidone, sucrose, and gum arabic; (c) humectants, such as glycerin; (d) disintegrants, such as agar, calcium carbonate, potato starch or cassava starch, alginate, certain complex silicates, and sodium carbonate; (e) slowing agents, such as paraffin wax; (f) absorption accelerators, such as quaternary ammonium compounds; (g) wetting agents, such as cetyl alcohol and glyceryl monostearate; (h) adsorbents, such as kaolin; and (i) lubricants, such as talc, calcium stearate, magnesium stearate, solid polyethylene glycol, sodium dodecyl sulfate, or mixtures thereof. Buffers may also be included in capsules, tablets, and pills.

[0038] Solid dosage forms such as tablets, sugar pills, capsules, pellets, and granules can be prepared using coatings and shells, such as casings and other materials known in the art. They may contain opacifying agents, and the release of the active compound or compound from such compositions can be delayed in a portion of the digestive tract. Examples of encapsulating components that can be used are polymeric substances and waxes. If necessary, the active compound may also be formed into microcapsules with one or more of the excipients described above.

[0039] Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, or tinctures. In addition to the active compound, liquid dosage forms may contain inert diluents conventionally used in the art, such as water or other solvents, solubilizers and emulsifiers, e.g., ethanol, isopropanol, ethyl carbonate, ethyl acetate, propylene glycol, 1,3-butanediol, dimethylformamide, and oils, particularly cottonseed oil, peanut oil, corn germ oil, olive oil, castor oil, and sesame oil, or mixtures of these substances.

[0040] In addition to these inert diluents, the composition may also contain auxiliaries such as wetting agents, emulsifiers and suspending agents, sweeteners, flavoring agents and fragrances.

[0041] In addition to the active compound, the suspension may contain suspending agents such as ethoxylated isooctadecyl alcohol, polyoxyethylene sorbitol and dehydrated sorbitol esters, microcrystalline cellulose, aluminum methoxide and agar, or mixtures of these substances.

[0042] Compositions for parenteral injection may comprise physiologically acceptable sterile aqueous or anhydrous solutions, dispersions, suspensions, or emulsions, and sterile powders for reconstitution into sterile injectable solutions or dispersions. Suitable aqueous and non-aqueous carriers, diluents, solvents, or excipients include water, ethanol, polyols, and suitable mixtures thereof.

[0043] Dosage forms of the compounds of the present invention for topical administration include ointments, powders, patches, sprays, and inhalers, such as nasal mucosal delivery formulations. The active ingredient is mixed under sterile conditions with a physiologically acceptable carrier and any preservatives, buffers, or propellants that may be necessary.

[0044] The pharmaceutically acceptable excipients described in this invention refer to substances other than the active ingredient contained in the dosage form.

[0045] The pharmaceutically acceptable adjuvant component described in this invention possesses certain physiological activities. However, the addition of this component does not alter the dominant role of the aforementioned pharmaceutical composition in the disease treatment process; rather, it merely exerts an adjuvant effect. These adjuvant effects are simply the utilization of the known activity of the component, and are a commonly used adjuvant therapy method in the pharmaceutical field. If the aforementioned adjuvant component is used in combination with the pharmaceutical composition of this invention, it should still fall within the scope of protection of this invention.

[0046] Specifically, the hypoxanthin derivatives provided by this invention, when used in the preparation of drugs for treating nephropathy and / or renal fibrosis, can significantly improve nephropathy and / or renal fibrosis. More importantly, the hypoxanthin derivatives provided by this invention can improve one or more types of idiopathic, secondary nephropathy and / or renal fibrosis.

[0047] The hypoxanthin derivatives provided by this invention have at least the following beneficial technical effects:

[0048] This invention provides the application of hypoxanthine derivatives in the preparation of drugs for treating kidney disease and / or renal fibrosis. The pharmacological activity of structurally modified and altered hypoxanthine derivatives in treating kidney disease and / or renal fibrosis was tested in various animal disease models. Data on the activity in preventing and treating different types of kidney disease and / or renal fibrosis are provided, confirming that they all have good activity, with effects significantly superior to the clinically commonly used drug nintedanib, and also significantly superior to hypoxanthine derivatives A, B, and C and other hypoxanthine derivatives in the prior art. In other words, this invention provides a novel framework for screening new compounds for the preparation of drugs for treating kidney disease and / or renal fibrosis, laying a theoretical foundation for the development of novel lead compounds. Brief description of the attached figures

[0049] Figure 1 HE images of the kidneys of mice in each group in a mouse model of renal interstitial fibrosis induced by unilateral ureteral ligation.

[0050] Figure 2 Masson plots of the kidneys of mice in different groups of a mouse model of renal interstitial fibrosis induced by unilateral ureteral ligation.

[0051] Figure 3 HE images of the kidneys of mice in different groups in a mouse model of adenine-induced kidney injury. Detailed Implementation

[0052] To make the objectives, advantages, and technical solutions of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementations obtained by those skilled in the art without creative effort, including extended studies on the treatment of nephropathy and / or renal fibrosis using hypoxanthine derivatives of this invention, are within the scope of protection of this invention.

[0053] Through research on the medicinal chemistry and chemical processes of natural products, numerous plant endogenous compounds and derivatives have been developed. Modification and alteration of the structures of natural products have yielded many derivatives with excellent pharmacological and chemical activities. This invention provides the application of hypoxanthine derivatives in the preparation of drugs for treating kidney disease and / or renal fibrosis. By testing the pharmacological activity of structurally modified hypoxanthine derivatives in treating kidney disease and / or renal fibrosis, and by evaluating their pharmacological activity in various animal disease models, data on their activity in preventing and treating different types of kidney disease and / or renal fibrosis are provided, confirming that they all possess good activity, with effects significantly superior to the clinically commonly used drug nintedanib, and also significantly superior to hypoxanthine derivatives A, B, and C, and other hypoxanthine derivatives in the prior art. Therefore, this invention provides a novel framework for screening new compounds for the preparation of drugs for treating kidney disease and / or renal fibrosis, laying a theoretical foundation for the development of novel lead compounds.

[0054] The structures of hypoxanthine derivatives A (control 1), B (control 2), and C (control 3) are shown below:

[0055]

[0056] Hypoxanthine derivatives A (control 1), B (control 2), and C (control 3) were prepared according to the method used to prepare compounds 17, 13, and 7, respectively.

[0057] The application of the hypoxanthine derivatives provided by the present invention in the preparation of drugs for treating kidney disease and / or renal fibrosis is described in detail below with reference to Examples 1 to 3.

[0058] Example 1: Preparation method of compounds 1 to 18

[0059] According to a preferred embodiment, compounds 1 to 18 are prepared by alkylation of hypoxanthin.

[0060] This embodiment provides preparation methods for 18 compounds, and the structures of all obtained compounds were determined by nuclear magnetic resonance spectroscopy and mass spectrometry.

[0061] Preparation of Compound 1 and Compound 5

[0062] The synthetic routes for compounds 1 and 5 are shown below:

[0063]

[0064] Reaction: (1) At 0℃, 3.45g NaH (4.5eq) was added to a 250mL four-necked flask. After evacuating the gas 3 times, 40mL (8V) of anhydrous THF was slowly added under N2 atmosphere; (2) 12.3mL of isopropanol (4.5eq) was slowly added dropwise to the system and the reaction was allowed to proceed for 30min; (3) Subsequently, 5g of compound 1 (1.0eq) was slowly added dropwise to a 100mL (20V) isopropanol mixture to the reaction system; (4) The temperature was raised to 80℃ and the system was allowed to react for 10h.

[0065] Post-processing: (1) After the reaction was complete, water was added to quench the reaction and acetic acid was added to neutralize the pH to 8-10; (2) Ethyl acetate was extracted 5 times and the organic phases were combined; (3) The organic phase was dried with anhydrous sodium sulfate, concentrated and then separated by rapid silica gel column chromatography to obtain a pale yellow solid; (4) TLC monitoring: developing solvent: dichloromethane / methanol = 10:1 Rf(compound 1) = 0.4.

[0066] The relevant spectral data for compounds 1 and 5 are as follows:

[0067] Compound 1: 1H NMR (400MHz, DMSO-d6) δ 13.33 (s, 1H), 8.44 (s, 1H), 8.32 (s, 1H), 5.55 (hept, J = 6.1Hz, 1H), 1.37 (d, J = 6.2Hz, 6H). HRMS (ESI-TOF) calculated for C8H10N4OH+[M+H+]: 179.09; found 179.10.

[0068] Compound 5: 11H NMR (400MHz, DMSO-d6) δ 13.37 (s, 1H), 8.47 (s, 1H), 8.35 (s, 1H), 5.57 (hept, J = 6.2Hz, 1H), 1.39 (d, J = 6.2Hz, 6H). HRMS (ESI-TOF) [M+H+]: 179.09; found 179.00.

[0069] Preparation of compounds 2, 4 and 6

[0070] The synthetic routes for compounds 2, 4, and 6 are shown below:

[0071]

[0072] The relevant spectral data for compounds 2, 4, and 6 are as follows:

[0073] Compound 2: 1found 179.30.

[0074] Compound 4: 1 H NMR(400MHz,Chloroform-d)δ8.58(s,1H),8.07(s,1H),5.63(hept,J=6.2Hz,1H),4.90(hept,J =6.7Hz,1H),1.59(d,J=6.8Hz,6H),1.44(d,J=6.2Hz,6H).HRMS(ESI-TOF)[M+H+]:221.27; found 221.20.

[0075] Compound 6: 1 found 179.30.

[0076] Preparation of compound 3

[0077] The synthetic route for compound 3 is shown below:

[0078]

[0079] The relevant spectral data for compound 3 are as follows:

[0080] Compound 3: 1 H NMR (400MHz, DMSO-d6) δ8.43 (s, 1H), 8.19 (s, 1H), 5.08 (hept, J = 6.9 Hz, 1H), 4.71 (hept, J = 6. 8Hz,1H),1.52(d,J=6.8Hz,6H),1.41(d,J=6.9Hz,6H).HRMS(ESI-TOF)[M+H+]:221.27; found 221.30.

[0081] Preparation of compounds 7 to 15

[0082] Compounds 7 through 15 were prepared using the same method as compound 3 described above.

[0083] The relevant spectral data for compounds 7 through 15 are as follows:

[0084] Compound 7: 1 found 193.10.

[0085] Compound 8: 1 H NMR(500MHz,Chloroform-d)δ8.55(s,1H),7.95(d,J=0.9Hz,1H),4.85(heptd,J=5.2,0.5Hz,1H) ,4.62(q,J=6.5Hz,2H),1.57(s,3H),1.50(t,J=6.5Hz,3H).HRMS(ESI-TOF)[M+H+]:207.12; found 207.10.

[0086] Compound 9: 1 H NMR (500MHz, Chloroform-d) δ8.51 (s, 1H), 7.57 (d, J = 0.3Hz, 1H), 4.57 (heptd, J = 5.0, 0.7Hz, 1H), 4.61 (t, J = 5. 4Hz,2H),1.90(qt,J=7.3,5.9Hz,2H),1.63(s,6H),1.15(t,J=7.4Hz,3H).HRMS(ESI-TOF)[M+H+]:221.13; found 221.10.

[0087] Compound 10: 1 H NMR(500MHz,Chloroform-d)δ8.37(s,1H),5.33–5.27(m,3H),4.74–4.64(m,2H),1.25 (d,J=6.2Hz,6H),1.17(dd,J=6.7,5.2Hz,12H).HRMS(ESI-TOF)[M+H+]:265.20; found 265.20.

[0088] Compound 11: 1H NMR (500MHz, Chloroform-d) δ7.99–7.88 (m, 2H), 4.83 (pd, J=5.6, 0.8Hz, 1H), 2.32 (s, 3H), 1.53 (s, 6H). HRMS (ESI-TOF) [M+H+]: 221.10; found 221.10.

[0089] Compound 12: 1 H NMR(500MHz,Chloroform-d)δ7.99–7.90(m,2H),4.85(heptd,J=5.2,0.5Hz,1H),2.54( q,J=7.7Hz,2H),1.55(s,3H),1.19–1.11(m,3H).HRMS(ESI-TOF)[M+H+]:235.10; found 235.10.

[0090] Compound 13: 1 H NMR(500MHz,Chloroform-d)δ8.42(s,1H),7.84(s,1H),4.61(s,1H),1.52(s,6H).HRMS(ESI-TOF)[M+H+]:179.09; found 179.09.

[0091] Compound 14: 1 H NMR(500MHz,Chloroform-d)δ8.43(s,1H),8.32(s,1H),4.73(s,1H),1.32(s,6H).HRMS(ESI-TOF)[M+H+]:179.09; found 179.09.

[0092] Compound 15: 1 H NMR(500MHz,Chloroform-d)δ8.46(s,1H),8.32(s,1H).HRMS(ESI-TOF)[M+H+]:137.05; found 137.05.

[0093] Preparation of compounds 16-18

[0094] The synthetic routes for compounds 16 to 18 are shown below:

[0095]

[0096] The relevant spectral data of compounds 16 to 18 are as follows:

[0097] Compound 16: 1H NMR(500MHz,Chloroform-d)δ8.07(s,1H),7.82(s,1H),4.61(s,1H),1.52(s,6H).HRMS(ESI-TOF)[M+H+]:179.09; found 179.09.

[0098] Compound 17: 1 H NMR(500MHz,Chloroform-d)δ8.32(s,1H),8.05(s,1H),4.35(s,1H),1.35(s,6H).HRMS(ESI-TOF)[M+H+]:179.09; found 179.10.

[0099] Compound 18: 1 H NMR(500MHz,Chloroform-d)δ8.32(s,1H),8.02(s,1H).HRMS(ESI-TOF)[M+H+]:137.05; found 137.04.

[0100] Example 2: The anti-renal fibrosis activity of compounds 1-18 obtained in Example 1.

[0101] Experimental Methods: A mouse model of renal fibrosis induced by unilateral ureteral ligation was established. The principle is as follows: after obstruction, urine retention compresses the renal tubules, leading to progressive necrosis of the tubular epithelial cells, infiltration of interstitial inflammatory cells, and gradual replacement of the necrotic tubular tissue by fibrous scarring, ultimately resulting in progressive renal fibrosis. This is similar to the dilation of the renal pelvis and calyces due to urinary tract obstruction (kidney stones) in clinical practice, where urine retention is collectively referred to as hydronephrosis. Because of the accumulation of urine within the kidney, the pressure increases, causing the renal pelvis and calyces to enlarge and the renal parenchyma to atrophy, ultimately leading to renal tissue necrosis and loss of function.

[0102] After one week of acclimatization feeding, SPF-grade male C57BL / 6 mice (weighing approximately 22–25 g) were randomly divided into a blank control group and a model group according to their body weight. In the model group, the left ureter was bluntly dissected (to reduce additional damage), and permanent ligation was performed at the renal pelvis orifice and the upper 1 / 3 of the ureter. The left ureter was then cut between the two ligation points, and the abdomen was closed by suturing layer by layer. In the sham surgery group, the ureter was freed after abdominal opening, but without ligation, and the abdomen was closed directly. One week after modeling, surviving mice were randomly divided into three groups based on their body weight and other indicators: model group, control groups 1-4, and compound groups 1-18, with 15 mice in each group. Mice in each group were administered medication via gavage. The blank control group and model group received the same volume of physiological saline as the drug groups. Control groups 1-3 received hypoxanthin derivatives A-C at 60 mg / kg / day, control group 4 received the control drug nintedanib at 60 mg / kg / day, and compound groups 1-18 received compounds 1-18 at 60 mg / kg / day. Administered twice daily for 7 consecutive days.

[0103] Mice were fasted for 12 hours before sampling, and urine was collected from each group of mice. Mice were anesthetized with tribromoethanol solution (300 mg / kg), the thoracic cavity was opened, and blood was collected from the right atrium. The blood was centrifuged to separate the supernatant serum. Biochemical indicators in urine and serum, namely CREA2, UA2, and UREAL, were detected to evaluate renal function. Kidney tissue was collected for HE and MASSON staining, and scored according to the 5-grade histological scoring system. The results are shown below.

[0104] HE results from the kidneys of mice in each group ( Figure 1 It can be seen that, compared with the blank group, the model group showed severe vacuolar degeneration of renal tubular epithelial cells, more severe dilation of renal tubules, and hemorrhage in the renal tubular spaces. Compared with the model group, the renal tissue of the compound 1-18 intervention group showed a significant reduction in the degree of vacuolar degeneration of renal tubular epithelial cells, less obvious dilation of renal tubules, and significantly reduced hemorrhage in the renal tubular spaces. This indicates that the compounds 1-18 have a significant anti-renal fibrosis effect and are significantly better than the control groups 1-3 (hypoxanthin derivatives A-C) and nintedanib.

[0105] Table 1. HE score of mouse kidney tissue in each group

[0106] Group score Group score Blank control group 0.6±0.2 Compound 7 1.6±0.1 Model group 3.2±0.2 Compound 8 1.2±0.2 Control group 1 3.0±0.3 Compound 9 1.7±0.1 Control group 2 2.9±0.2 Compound 10 2.2±0.1 Control group 3 3.1±0.3 Compound 11 2.3±0.1 Control group 4 2.4±0.2 Compound 12 2.1±0.1 Compound 1 1.8±0.1 Compound 13 2.2±0.1 Compound 2 1.5±0.2 Compound 14 1.7±0.2 Compound 3 1.4±0.1 Compound 15 1.9±0.1 Compound 4 2.0±0.1 Compound 16 2.1±0.2 Compound 5 2.3±0.1 Compound 17 1.9±0.1 Compound 6 1.7±0.2 Compound 18 2.0±0.1

[0107] Masson staining from each group ( Figure 2 The results showed that, compared with the control group, the renal tubular epithelial cells in the model group had irregular morphology, and a large number of purple collagen fibers were aggregated between the tissues. The number of purple collagen fibers in the kidney tissue of the intervention groups of compounds 1-18 was significantly reduced compared with the model group (P<0.05).

[0108] Table 2. Semi-quantitative analysis results of Masson staining collagen volume fraction in kidney tissue of mice in each group.

[0109]

[0110]

[0111] As shown in Tables 1 and 2, compared with the blank group, the HE score and semi-quantitative analysis of stained collagen volume fraction in serum and urine of the model group were significantly increased. Compared with the model group, the HE score and semi-quantitative analysis of stained collagen volume fraction in the intervention groups of compounds 1-18 were significantly decreased. This indicates that compounds 1-18 can improve renal function in mouse models of renal interstitial fibrosis induced by unilateral ureteral ligation, and the improvement effect is better than that of control groups 1-3 (hypoxanthin derivatives A-C) and control group 4 nintedanib.

[0112] Table 3. Results of serum renal function indicators in each group

[0113]

[0114]

[0115] Table 4. Results of urine renal function tests for each group

[0116]

[0117]

[0118] As shown in Tables 3 and 4, compared with the blank group, the serum and urine CREA2, UA2, and UREAL levels in the model group were significantly increased. Compared with the model group, the CREA2, UA2, and UREAL levels in the compound 1-18 intervention group were significantly decreased. This indicates that compounds 1-18 can improve renal function in mouse models of renal fibrosis induced by unilateral ureteral ligation, and the improvement effect is better than that of control groups 1-3 (hypoxanthin derivatives A-C) and control group 4 (nintedanib).

[0119] Example 3: The anti-nephropathy activity of compounds 1-18 obtained in Example 1.

[0120] Experimental Methods: An adenine-induced kidney injury mouse model was established, which is a typical model of kidney disease and kidney injury. The principle behind long-term administration of adenine to mice is to induce metabolic abnormalities similar to those in human kidney failure. These disorders include azotemia, uremic toxin deposition, amino acid and electrolyte metabolic disorders, and hormonal imbalances. The adenine-induced kidney disease mouse model effectively mimics the progression of human kidney disease by promoting renal tubular interstitial fibrosis, tubular atrophy, and crystal formation.

[0121] SPF-grade male C57BL / 6 mice (approximately 22–25 g) were acclimatized for one week, and then all mice were randomly divided into four groups according to body weight: blank control group, model group, control groups 1–4, and compound groups 1–18, with 15 mice in each group. Adenine was administered via gavage to establish the model. The model group, control groups 1–4, and compound groups 1–18 were given adenine suspension at 250 mg / kg / day, while the blank control group received the same volume of physiological saline as the drug group daily for 7 consecutive days. Except for the blank control group, all other groups were then administered adenine at 135 mg / kg via gavage every other day for 21 days. After modeling, mice in each group were administered medication via gavage. The blank control group and model group were given the same volume of physiological saline as the drug groups based on their body weight. Control groups 1-3 were given hypoxanthin derivatives A-C at 60 mg / kg / day, control group 4 was given the control drug losartan at 20 mg / kg / day, and groups 1-18 were given compounds 1-18 at 60 mg / kg / day. Administered twice daily for 28 consecutive days.

[0122] Mice were fasted for 12 hours before sampling, and urine was collected from each group of mice. Mice were anesthetized with tribromoethanol solution (300 mg / kg), the thoracic cavity was opened, and blood was collected from the right atrium. The blood was centrifuged to separate the supernatant serum. Biochemical indicators in urine and serum were detected: CREA2, UA2, and UREAL to evaluate renal function. Serum TNF-α and IL-6 were detected to evaluate inflammation. Kidney tissue was collected for HE staining and scored according to a 5-grade histological scoring system. The results are shown below.

[0123] HE description

[0124] HE results from the kidneys of mice in each group ( Figure 3 As shown in Table 5, the HE scores of the kidney tissues of mice in each group indicate that, compared with the blank group, the model group showed severe vacuolar degeneration of renal tubular epithelial cells and a large number of inflammatory cell infiltrations. Compared with the model group, the kidney tissues of the compound 1-18 intervention group showed significantly reduced vacuolar degeneration of renal tubular epithelial cells and significantly reduced inflammatory cells, indicating that the compounds 1-18 have significant anti-nephropathy effects and are superior to the control groups 1-3 (hypoxanthin derivatives A-C) and 4 losartan.

[0125] Table 5. HE score of mouse kidney tissue in each group

[0126]

[0127]

[0128] Kidney function description

[0129] As shown in Tables 6 and 7, compared with the blank group, the serum and urine CREA2, UA2, and UREAL levels in the model group were significantly increased. Compared with the model group, the CREA2, UA2, and UREAL levels in the compound 1-18 intervention group were significantly decreased, indicating that compounds 1-18 can improve renal function in adenine-induced renal injury mouse model, and the improvement effect is better than that of control group 1-3 (hypoxanthine derivatives A-C) and control group 4 losartan.

[0130] Table 6. Results of serum renal function indicators in each group

[0131]

[0132]

[0133] Table 7. Results of urine renal function tests for each group

[0134]

[0135]

[0136] As shown in Table 8, compared with the blank group, the serum levels of IL-6 and TNF-α in the model group were significantly increased, indicating that an inflammatory response occurred in the mice. Compared with the model group, the serum levels of IL-6 and TNF-α in the compound 1-18 intervention groups were significantly decreased, indicating that compounds 1-18 can improve the inflammatory response in the adenine-induced kidney injury mouse model, and the improvement effect is better than that of control groups 1-3 (hypoxanthine derivatives A-C) and control group 4 (losartan).

[0137] Table 8. Results of serum IL-6 and TNF-α levels in each group

[0138]

[0139]

[0140] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0141] References

[0142] 1. Liu Y.Renal fibrosis:new insights into the pathogenesis andtherapeutics.Kidney Int.2006Jan;69(2):213-7.doi:10.1038 / sj.ki.5000054.PMID:16408108.

[0143] 2. Yan Qing, Cheng Zhimei, Zhang Shuai, et al. Therapeutic effect and molecular mechanism of pirfenidone on renal fibrosis rats [J]. Journal of Guizhou Medical University, 2024, 49(03):354-360. DOI:10.19367 / j.cnki.2096-8388.2024.03.005.

[0144] 3. Nastase MV, Zeng-Brouwers J, Wygrecka M, Schaefer L. Targeting renal fibrosis: Mechanisms and drug delivery systems. Adv Drug Deliv Rev. 2018Apr; 129: 295-307. doi: 10.1016 / j.addr.2017.12.019. Epub 2017Dec 27.PMID:29288033.

[0145] 4. Si Changxing, Ding Yanyan, Yin Fengxian. Gingerol alleviates bleomycin-induced pulmonary fibrosis in mice [J]. Basic Medicine and Clinical Practice, 2023, 43(12):1827-1833.

Claims

1. The use of a hypoxanthine derivative in the preparation of drugs for treating kidney disease and / or renal fibrosis, characterized in that, The hypoxanthin derivative has therapeutic activity for nephropathy and / or renal fibrosis, and the hypoxanthin derivative has one of the following structures: in: R1 can be any of O, N, C, S or = O; R2, R3, and R4 can be chosen as H and C1-C, respectively. 18 Alkyl or halogen-substituted C1-C 18 Alkyl, trifluoromethyl, sulfonyl, sulfonamide, sulfinyl, amino acid, 2-[bis(neopentyloxy)methoxy]phosphonomethoxyethyl, C1-C 18 Fatty acid group, C3-C 12 Heterocyclic groups, C1-C 18 Fatty acids; or C1-C atoms in which R2, R3, and R4 are optionally substituted with oxygen, sulfur, or nitrogen atoms. 18 The alkyl or fatty acid group; when R3 or R4 is substituted, the double bond is attached to the unsubstituted N position, and when all are substituted, there is no double bond.

2. The use of the hypoxanthine derivative according to claim 1 in the preparation of drugs for treating kidney disease and / or renal fibrosis, characterized in that, The hypoxanthine derivatives mentioned are one or more of the following compounds:

3. The use of the hypoxanthine derivative according to claim 1 in the preparation of drugs for treating kidney disease and / or renal fibrosis, characterized in that, The medications mentioned for treating kidney disease and / or renal fibrosis include those that have the efficacy of preventing and treating kidney disease and / or renal fibrosis and their complications.

4. The use of the hypoxanthine derivative according to claim 1 in the preparation of drugs for treating kidney disease and / or renal fibrosis, characterized in that, The aforementioned drug for treating kidney disease and / or renal fibrosis is a preparation made by adding pharmaceutically acceptable excipients or auxiliary ingredients, with hypoxanthine derivatives or their salts as the active ingredient.

5. The use of the hypoxanthine derivative according to claim 4 in the preparation of drugs for treating kidney disease and / or renal fibrosis, characterized in that, The preparation is an oral preparation, an injectable preparation, or a nasal mucosal delivery preparation.

6. The use of the hypoxanthine derivative according to claim 1 in the preparation of drugs for treating nephropathy and / or renal fibrosis, characterized in that, The kidney disease includes one or more of idiopathic nephropathy and secondary nephropathy, and the renal fibrosis includes one or more of idiopathic renal fibrosis and secondary renal fibrosis.

7. Compounds having the following structure: in: R1 can be any of O, N, C, S or = O; R2, R3, and R4 can be chosen as H and C1-C, respectively. 18 Alkyl or halogen-substituted C1-C 18 Alkyl, trifluoromethyl, sulfonyl, sulfonamide, sulfinyl, amino acid, 2-[bis(neopentyloxy)methoxy]phosphonomethoxyethyl, C1-C 18 Fatty acid group, C3-C 12 Heterocyclic groups, C1-C 18 Fatty acids; or C1-C atoms in which R2, R3, and R4 are optionally substituted with oxygen, sulfur, or nitrogen atoms. 18 The alkyl or fatty acid group; when R3 or R4 is substituted, the double bond is attached to the unsubstituted N position, and when all are substituted, there is no double bond.

8. The compound according to claim 7, selected from the group consisting of:

9. A pharmaceutical composition comprising the compound of claim 7 or 8 or a pharmaceutically acceptable salt thereof.

10. The pharmaceutical composition according to claim 9, further comprising a pharmaceutically acceptable excipient or auxiliary ingredient.

11. The pharmaceutical composition according to claim 9 or 10, wherein it is an oral formulation, an injectable formulation, or a nasal mucosal administration formulation.

12. A method for treating kidney disease and / or renal fibrosis, characterized in that, Administer to an individual in need an effective amount of the compound of claim 7 or 8 or a pharmaceutically acceptable salt thereof, or the pharmaceutical composition of claims 9-11.

13. The method according to claim 12, characterized in that, The kidney disease includes one or more of idiopathic nephropathy and secondary nephropathy, and the renal fibrosis includes one or more of idiopathic renal fibrosis and secondary renal fibrosis.

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