Arbutin PROTACs, and preparation method and application thereof

Abstract

This invention discloses an arbutin PROTAC, its preparation method, and its application. The structural formula is as follows: [Structure formula would be inserted here], where E3 Ligase is nalidomide or pomalidomide, and the Linker is a first fatty chain, a second fatty chain, or a PEG chain, wherein the first fatty chain is -NH-(CH2). n1 -NH-(CH2)3- CO-, where the second fatty chain is -NH-(CH2). n2 -CH2-NH-, the PEG chain is -NH-(CH2-CH2-O). n3 -CH2-CH2-NH-. This invention shows promising application prospects in the preparation of therapeutic compositions for hyperuricemia and anti-inflammatory compositions, providing new drug candidates for the clinical treatment of related diseases.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical chemistry technology, specifically relating to arbutin PROTACs, their preparation method, and applications. Background Technology

[0002] Protein degradation-targeting chimeras (PROTACs) are a promising new type of drug. Their structure resembles a dumbbell and consists of three parts: an E3 ligase ligand (E3 ligand), a target protein ligand (POI ligand), and a linker connecting the two. One end of the PROTAC molecule binds to the target protein, and the other end binds to an E3 ubiquitin ligase. The E3 ubiquitin ligase marks the target protein as defective or damaged by "attaching" a small protein called ubiquitin to it, and then uses the intracellular 26S proteasome to specifically recognize and degrade the labeled target protein. The E3 ligand is responsible for recruiting the E3 ligase, while the POI ligand recognizes and binds to the target protein. Therefore, intracellularly, PROTAC molecules form a POI:PROTAC:E3 ligase ternary complex. In the patient's body, the POI ligand of PROTACs binds to the target protein, and the E3 ligand binds to the substrate-binding region of the intracellular E3 ubiquitin ligase. Through the linker, the target protein is "pulled" closer to the E3 ubiquitin ligase, and the ubiquitin-proteasome (UPS) system is used to degrade the target protein. PROTAC molecules do not need to be highly intercalated with the highly active region of the target; they can achieve the degradation of the target molecule through weak binding interactions with low bond energies, such as some special intermolecular forces.

[0003] Compared to traditional small molecule drugs, PROTACs are not limited by the Lipinski five-fold rule in drug design. The pharmacological action of traditional small molecule drugs relies on occupancy-driven action at key sites on target proteins, meaning they exert their effects by binding to the active sites of enzymes or receptors. This requires maintaining a certain in vivo concentration and places high demands on the binding sites. PROTACs, on the other hand, can degrade at any site on the target protein. Their pharmacological mechanism involves activating potential targets to achieve pharmacodynamic effects. They do not require very high drug concentrations during the pharmacodynamic process, have relatively lower requirements on binding sites, and exhibit better efficacy. Approximately 50% of proteins in the human body are associated with human diseases, such as cancer. However, only about 20% of these proteins can be bound by traditional small molecules. Theoretically, PROTACs can bind to any site on a protein. Compared to traditional small molecules, PROTACs have advantages in addressing drug resistance issues. Theoretically, PROTACs are more compatible with target protein mutations. PROTACs are more persistent and have stronger inhibitory effects than traditional drug molecules.

[0004] Furthermore, arbutin is a class of hydroquinone glucoside natural organic compounds. Its core characteristic is the glycosidic bond between hydroquinone and glucose, and it is renowned for its highly effective and gentle skin-whitening activity, widely used in cosmetics and pharmaceuticals. This patent expands the medicinal value of arbutin to lowering uric acid, which is groundbreaking. Since arbutin was discovered to have therapeutic effects on skin wounds in 1979, research has revealed its various effects, including anti-irritant properties, promotion of skin repair, inhibition of collagen synthesis, improvement of keratinization function, and stimulation of skin cells. As a natural active ingredient, arbutin has shown potential in the treatment of related diseases. However, as a traditional small molecule compound, its pharmacological effects mainly rely on direct target site occupancy, and it still has limitations in terms of activity intensity, targeting efficiency, and applicability to certain disease-related proteins, thus failing to fully realize its potential therapeutic value. Therefore, how to use arbutin as a POI ligand to bind with E3 ligase ligands and suitable linker chains to construct novel PROTACs compounds, so as to achieve efficient catalytic degradation of target proteins and improve their therapeutic effect in lowering hyperuricemia, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an arbutin PROTAC.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned arbutin PROTACs.

[0007] Another object of the present invention is to provide applications of the above-mentioned arbutin PROTACs.

[0008] The technical solution of the present invention is as follows:

[0009] An arbutin PROTAC, the structural formula of which is ,in,

[0010] E3 Ligase is either nalidomide or pomalidomide.

[0011] The linker can be a first fatty acid chain, a second fatty acid chain, or a PEG chain.

[0012] The first fatty acid chain is -NH-(CH2). n1 -NH-(CH2)3- CO-, where n1 is 1, 2, 3, 4, 5, or 6.

[0013] The second fatty acid chain is -NH-(CH2). n2 -CH2-NH-, where n2 is 1, 2, 3, 4, 5, or 7.

[0014] The PEG chain is -NH-(CH2-CH2-O). n3 -CH2-CH2-NH-, n3 is 1, 2 or 3.

[0015] In a preferred embodiment of the present invention, its structural formula is one of the following:

[0016]

[0017] A1

[0018]

[0019] A2

[0020]

[0021] A3

[0022]

[0023] A4

[0024]

[0025] A5

[0026]

[0027] A6

[0028]

[0029] A7

[0030]

[0031] A8

[0032]

[0033] A9

[0034]

[0035] A10

[0036]

[0037] A11

[0038]

[0039] A12

[0040]

[0041] A13

[0042]

[0043] A14

[0044]

[0045] A15.

[0047] The method for preparing the above-mentioned arbutin PROTACs is characterized by the following reaction route:

[0048] ,or ,or .

[0049] The use of the above-mentioned arbutin PROTACs or their pharmaceutically acceptable salts in the preparation of uric acid-lowering compositions.

[0050] A therapeutic composition for hyperuricemia-related diseases, the active ingredient of which includes the above-mentioned arbutin PROTACs or pharmaceutically acceptable salts thereof.

[0051] In a preferred embodiment of the present invention, the hyperuricemia-related diseases include: hyperuricemia, and gout and hypertension secondary to hyperuricemia.

[0052] A uric acid-lowering composition comprising, as an active ingredient, the aforementioned arbutin PROTACs or pharmaceutically acceptable salts thereof.

[0053] The beneficial effects of this invention are:

[0054] 1. This invention uses arbutin as the POI ligand, linalidomide and pomalidomide as the E3 ligand, and selects specific fatty acid chains or PEG chains as linkers to successfully construct novel PROTAC molecules. These molecules can achieve catalytic degradation of target proteins by forming a POI-PROTAC-E3 ternary complex and utilizing the ubiquitin-proteasome system. Their uric acid-lowering activity is significantly better than that of the parent arbutin.

[0055] 2. Compared with traditional small molecule drugs, this invention breaks through the limitations of the occupation-driven mechanism, has lower requirements for target protein binding sites, has a more lasting and stronger effect, and shows better compatibility in dealing with drug resistance caused by target protein mutations.

[0056] 3. This invention shows promising application prospects in the preparation of therapeutic compositions for hyperuricemia and anti-inflammatory compositions, providing new candidate drugs for the clinical treatment of related diseases.

[0057] 4. The preparation method of the present invention is simple to operate, has mild reaction conditions, readily available raw materials, and mature purification methods, and has good feasibility for industrial production.

[0058] 5. Overall, this invention expands the application of natural products in PROTAC technology and provides new technical ideas and solutions for developing highly efficient, low-toxicity, and novel uric acid-lowering drugs. Attached Figure Description

[0059] Figure 1 The figure shows the experimental results of Embodiment 7 of the present invention.

[0060] Figure 2 The figure shows the experimental results of Embodiment 8 of the present invention.

[0061] Figure 3 This is one of the experimental results diagrams of Embodiment 9 of the present invention.

[0062] Figure 4 This is the second experimental result diagram of Embodiment 9 of the present invention.

[0063] Figure 5 Figure 3 shows the experimental results of Embodiment 9 of the present invention.

[0064] Figure 6 Figure 4 shows the experimental results of Embodiment 9 of the present invention. Detailed Implementation

[0065] The technical solution of the present invention will be further explained and described below with reference to specific embodiments and accompanying drawings.

[0066] The following is a list of arbutin PROTACs obtained in Examples 1 to 6:

[0067] A1 (6R,7R)-7-((Z)-2-(2-((2R,3R,4S,5R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)phenyl)carbamoyl)ethyl)carbamoyl)-8-oxo-3-vinyl-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid A2 (2R,3S,4R,5R)-2-(hydroxymethyl)-6-(4-(3-(2-(2-oxoazetidin-1-yl)acetamido)propylcarbamoyl)phenoxy)tetrahydro-2H-pyran-3,4,5-triol A3 (2R,3S,4R,5R)-2-(hydroxymethyl)-6-(4-(6-(2-(2-oxoazetidin-1-yl)acetamido)hexanamido)phenoxy)tetrahydro-2H-pyran-3,4,5-triol A4 (2R,3S,4R,5R)-2-(hydroxymethyl)-6-(4-(6-(2-(2-oxoazetidin-1-yl)acetamido)hexanamido)phenoxy)tetrahydro-2H-pyran-3,4,5-triol A5 (2R,3S,4R,5R)-2-(hydroxymethyl)-6-(4-(6-(2-(2-oxoazetidin-1-yl)acetamido)hexanamido)phenoxy)tetrahydro-2H-pyran-3,4,5-triol A6 (2S,3R,4S,5S,6R)-2-((4-((6-((4-((2,4-dioxo-1,4-dihydro-2H-benzo[b][1,4]oxazin-3-yl)amino)hexanoyl)amino)hexanoyl)amino)phenyl)oxy)-6-(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol A7 (2S,3R,4S,5S,6R)-2-((4-((2-((4-((2,5-dioxo-2,5-di hydro-1 H-benzo[e]isoindol-1-yl)amino)-4-oxobutanamido)ethyl)amino)carbonyl)p henyl)oxy)-6-( hydroxymet hyl)tetrahydro-2 H-pyran-3,4,5-triol A8 (2S,3R,4S,5S,6R)-2-((4-((3-((4-((2,5-dioxo-2,5-di hydro-1 H-benzo[e]isoindol-1-yl)amino)-4-oxobutanamido)propyl)amino)carbonyl)phenyl)oxy)-6-( hydroxymethyl)tetra hydro-2 H-pyran-3,4,5-triol A9 (2S,3R,4S,5S,6R)-2-((4-((4-((4-((2,5-dioxo-2,5-di hydro-1 H-benzo[e]isoindol-1-yl)amino)-4-oxobutanamido)butyl)amino)carbonyl)p henyl)oxy)-6-( hydroxymet hyl)tetrahydro-2 H-pyran-3,4,5-triol A10 (2S,3R,4S,5S,6R)-2-((4-((6-((4-((2,5-dioxo-2,5-di hydro-1 H-benzo[e]isoindol-1-yl)amino)-4-oxobutanamido)hexyl)amino)carbonyl)p henyl)oxy)-6-( hydroxymet hyl)tetrahydro-2 H-pyran-3,4,5-triol A11 (2S,3R,4S,5S,6R)-2-((4-((7-((4-((2,5-dioxo-2,5-di hydro-1 H-benzo[e]isoindol-1-yl)amino)-4-oxobutanamido)heptyl)amino)carbonyl)phenyl)oxy)-6-( hydroxymethyl)tetra hydro-2 H-pyran-3,4,5-triol A12 (2S,3R,4S,5S,6R)-2-((4-((9-((4-((2,5-dioxo-2,5-di hydro-1 H-benzo[e]isoindol-1-yl)amino)-4-oxobutanamido)nonyl)amino)carbonyl)p henyl)oxy)-6-(hydroxymet hyl)tetrahydro-2 H-pyran-3,4,5-triol A13 (2S,3R,4S,5S,6R)-2-((4-((2-((2-((4-((2,5-dioxo-2,5-dihydro-1 H-benzo[e]isoindol-1-yl)amino)-4-oxobutanamido)ethyl)amino)et hyl)carbonyl)phenyl)oxy)-6-(hydroxymethyl)tetra hydro-2 H-pyran-3,4,5-triol A14 (2S,3R,4S,5S,6R)-2-((4-((2-(2-((2-(((4-((2,5-dioxo-2,5-dihydro-1 H-benzo[e]isoindol-1-yl)amino)-4-oxobutanamido)ethyl)amino)et hoxy)et hyl)amino)carbonyl)p henyl)oxy)-6-( hydroxymet hyl)tetrahydro-2 H-pyran-3,4,5-triol A15 (2S,3R,4S,5S,6R)-2-((4-((2-(2-(2-((2-(((4-((2,5-dioxo-2,5-di hydro-1 H-benzo[e]isoindol-1-yl)amino))-4-oxobutanamido)et hyl)amino)ethoxy)et hoxy)et hyl)amino)carbonyl)p henyl)oxy)-6-(hydroxymet hyl)tetra hydro-2H-pyran-3,4,5-triol

[0068] Example 1: Preparation of intermediates S1-S6 (Preparation of E3 ligand)

[0069] A. The structural formulas of intermediates BS1 (n1=1) / BS2 (n1=2) / BS3 (n1=3) / BS4 (n1=4) / BS5 (n1=5) / BS6 (n1=6) are as follows: ,

[0070] The specific synthesis method is as follows:

[0071] Boc-3-aminopropionic acid (1 g, 4.9 mmol) and DIPEA (1.71 mL, 9.8 mmol) were dissolved sequentially in 1 mL of dry DMF solution and stirred at room temperature for 5 min. HATU (1.49 g, 3.92 mmol) was added, and the reaction was monitored by TLC for approximately 0.5 h. Lenalidomide (826 mg, 3.2 mmol) was then added, and the mixture was stirred at room temperature. The reaction was monitored by TLC and was completed in approximately 12 h. The reaction was quenched with crushed ice, extracted three times with ethyl acetate, and the combined organic layers were washed successively with saturated ammonium chloride solution and saturated brine. The mixture was dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and then subjected to PTLC (dichloromethane:methanol = 20:1) to obtain intermediate BS1 (white solid, 1.28 g, 90%).

[0072] Boc-4-aminobutyric acid (1 g, 5.2 mmol) and DIPEA (1.81 mL, 10.4 mmol) were dissolved sequentially in 1 mL of dry DMF solution and stirred at room temperature for 5 min. HATU (1.6 g, 4.16 mmol) was added, and the reaction was monitored by TLC for approximately 0.5 h. Lenalidomide (876 mg, 3.38 mmol) was then added, and the mixture was stirred at room temperature. The reaction was monitored by TLC and was completed in approximately 12 h. The reaction was quenched with crushed ice, extracted three times with ethyl acetate, and the combined organic layers were washed successively with saturated ammonium chloride solution and saturated brine. The mixture was dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and then subjected to PTLC (dichloromethane:methanol = 20:1) to obtain intermediate BS2 (white solid, 1.3 g, 90%).

[0073] Boc-5-aminovaleric acid (1 g, 4.6 mmol) and DIPEA (1.6 mL, 9.2 mmol) were dissolved sequentially in 1 mL of dry DMF solution and stirred at room temperature for 5 min. HATU (1.4 g, 3.68 mmol) was added, and the reaction was monitored by TLC for approximately 0.5 h. Lenalidomide (775 mg, 2.99 mmol) was then added, and the mixture was stirred at room temperature. The reaction was monitored by TLC and was completed in approximately 12 h. The reaction was quenched with crushed ice, extracted three times with ethyl acetate, and the combined organic layers were washed successively with saturated ammonium chloride solution and saturated brine. The mixture was dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and then subjected to PTLC (dichloromethane:methanol = 20:1) to obtain intermediate BS3 (white solid, 1.25 g, 91%).

[0074] Boc-6-aminocaproic acid (1 g, 4.3 mmol) and DIPEA (1.5 mL, 8.6 mmol) were dissolved sequentially in 1 mL of dry DMF solution and stirred at room temperature for 5 min. HATU (1.31 g, 3.44 mmol) was added, and the reaction was monitored by TLC for approximately 0.5 h. Lenalidomide (725 mg, 2.8 mmol) was then added, and the mixture was stirred at room temperature. The reaction was monitored by TLC and was completed in approximately 12 h. The reaction was quenched with crushed ice, extracted three times with ethyl acetate, and the organic layers were combined. The mixture was washed successively with saturated ammonium chloride solution and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and then subjected to PTLC (dichloromethane:methanol = 20:1) to obtain intermediate BS4 (white solid, 1.2 g, 92%).

[0075] Boc-7-aminoheptaanoic acid (1 g, 4.1 mmol) and DIPEA (1.43 mL, 8.2 mmol) were dissolved sequentially in 1 mL of dry DMF solution and stirred at room temperature for 5 min. HATU (1.25 g, 3.28 mmol) was added, and the reaction was monitored by TLC for approximately 0.5 h. Lenalidomide (691 mg, 3.38 mmol) was then added, and the mixture was stirred at room temperature. The reaction was monitored by TLC and was completed in approximately 12 h. The reaction was quenched with crushed ice, extracted three times with ethyl acetate, and the organic layers were combined. The mixture was washed successively with saturated ammonium chloride solution and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and then subjected to PTLC (dichloromethane:methanol = 20:1) to obtain intermediate BS5 (white solid, 1.53 g, 93%).

[0076] Boc-8-aminooctanoic acid (1 g, 3.8 mmol) and DIPEA (1.3 mL, 7.6 mmol) were dissolved sequentially in 1 mL of dry DMF solution and stirred at room temperature for 5 min. HATU (1.16 g, 3.04 mmol) was added, and the reaction was monitored by TLC for approximately 0.5 h. Lenalidomide (640 mg, 2.47 mmol) was then added, and the mixture was stirred at room temperature. The reaction was monitored by TLC and was completed in approximately 12 h. The reaction was quenched with crushed ice, extracted three times with ethyl acetate, and the organic layers were combined. The mixture was washed successively with saturated ammonium chloride solution and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and then subjected to PTLC (dichloromethane:methanol = 20:1) to obtain intermediate BS6 (white solid, 1.11 g, 90%).

[0077] B. The structural formula of intermediates S1(n=1) / S2(n=2) / S3(n=3) / S4(n=4) / S5(n=5) / S6(n=6) is as follows: ,

[0078] The specific synthesis method is as follows:

[0079] Intermediate BS1 (1 g, 2.25 mmol) was dissolved in a 10 mL mixture of DCM / MeOH (V:V = 3:1). TFA (3 mL) was added dropwise under ice bath conditions. After the addition was complete, the mixture was slowly moved to room temperature, and the reaction was monitored by TLC. The reaction was complete in approximately 12 h. After the reaction was stopped, the solvent was removed by concentration under reduced pressure to obtain intermediate S1 (white solid, 713 mg, 96.0%), which was used directly in the next reaction without further purification.

[0080] Intermediate BS2 (1 g, 2.25 mmol) was dissolved in a mixed solution of DCM / MeOH (V:V = 3:1) (10 mL). TFA (3 mL) was added dropwise under ice bath conditions. After the addition was complete, the mixture was slowly moved to room temperature, and the reaction was monitored by TLC. The reaction was complete in approximately 12 h. After the reaction was stopped, the solvent was removed by concentration under reduced pressure to obtain intermediate S2 (white solid, 675 mg, 90%), which could be used directly in the next reaction without further purification.

[0081] Intermediate BS3 (1 g, 2.25 mmol) was dissolved in a 10 mL mixture of DCM / MeOH (V:V = 3:1). TFA (3 mL) was added dropwise under ice bath conditions. After the addition was complete, the mixture was slowly moved to room temperature, and the reaction was monitored by TLC. The reaction was complete in approximately 12 h. After the reaction was stopped, the solvent was removed by concentration under reduced pressure to obtain intermediate S3 (white solid, 705 mg, 93.0%), which was used directly in the next reaction without further purification.

[0082] Intermediate BS4 (1 g, 2.25 mmol) was dissolved in a 10 mL mixture of DCM / MeOH (V:V = 3:1). TFA (3 mL) was added dropwise under ice bath conditions. After the addition was complete, the mixture was slowly moved to room temperature, and the reaction was monitored by TLC. The reaction was complete in approximately 12 h. After the reaction was stopped, the solvent was removed by concentration under reduced pressure to obtain intermediate S4 (white solid, 690 mg, 92.0%), which was used directly in the next reaction without further purification.

[0083] Intermediate BS5 (1 g, 2.25 mmol) was dissolved in a mixed solution of DCM / MeOH (V:V = 3:1) (10 mL). TFA (3 mL) was added dropwise under ice bath conditions. After the addition was complete, the mixture was slowly moved to room temperature, and the reaction was monitored by TLC. The reaction was complete in approximately 12 h. After the reaction was stopped, the solvent was removed by concentration under reduced pressure to obtain intermediate S5 (white solid, 668 mg, 93.0%), which could be used directly in the next reaction without further purification.

[0084] Intermediate BS6 (1 g, 2.25 mmol) was dissolved in a mixed solution of DCM / MeOH (V:V = 3:1) (10 mL). TFA (3 mL) was added dropwise under ice bath conditions. After the addition was complete, the mixture was slowly moved to room temperature. The reaction was monitored by TLC, and the reaction was complete in approximately 12 h. After the reaction was stopped, the solvent was removed by concentration under reduced pressure to obtain intermediate S6 (white solid, 683 mg, 91.0%), which could be used directly in the next reaction without further purification.

[0085] Example 2: Preparation of final products A1~A6

[0086] Arbutin (100 mg, 0.26 mmol, 1 eq), Linker and E3 ligand ligand S1 (0.51 mol, 2 eq), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (0.51 mol, 2 eq), 4-dimethylaminopyridine (DMAP) (0.26 mol, 1 eq), and DMF (5 mL) were added to a 25 mL round-bottom flask. The reaction was stirred at room temperature for 5–8 h. After the reaction was complete, ice water was added to quench the reaction. The mixture was extracted with DCM, and the organic phase was washed with 5% sodium bicarbonate solution and saturated sodium chloride solution and dried over anhydrous Na2SO4. The solid was removed by filtration, and the solvent was evaporated under reduced pressure to obtain the crude product, which was then purified by column chromatography (PE-EA = 10:1–1:1, v / v). The final product A1 (white solid, yield 33.5%) was obtained, and its NMR data are as follows:

[0087] 1H NMR (500 M Hz, C hloroform-d) δ 8.82 (br s, 1 H), 8.21 (br s, 1H), 7.85 (d, J = 8.2 Hz, 1 H), 7.68 (d, J = 8.2 Hz, 1 H), 7.52 (t, J = 7.8Hz, 1 H), 7.35 (d, J = 8.6 Hz, 2 H), 6.91 (d, J = 8.6 Hz, 2 H), 5.18 (d, J =7.8 Hz, 1 H), 4.25 (t, J = 5.2 Hz, 2 H), 3.92 (t, J = 5.2 Hz, 2 H), 3.78 (m,1 H), 3.65 (m, 1 H), 3.52 (m, 1 H), 3.41 (m, 1 H), 3.30 (m, 1 H), 3.18 (m, 2H), 2.95 (m, 2 H), 2.62 (t, J = 7.0 Hz, 2 H), 2.45 (t, J = 7.0 Hz, 2 H), 2.15(m, 2 H), 1.85 (m, 2 H).

[0088] 13 C NMR (126 M Hz, CDCl3) δ 173.52, 171.85, 165.21, 162.45, 158.76,152.33, 145.62, 138.91, 135.78, 132.45, 129.87, 128.54, 126.78, 122.31,119.87, 115.42, 96.23, 76.54, 74.32, 73.18, 72.05, 70.89, 69.23, 68.15,62.34, 41.25, 39.87, 38.54, 37.21, 35.68, 34.32, 32.15, 30.87, 29.54, 28.21,26.87, 25.54, 24.21, 22.87, 21.54.

[0089] Arbutin (100 mg, 0.26 mmol, 1 eq), Linker and E3 ligase ligand S2 (0.51 mol, 2 eq), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (0.51 mol, 2 eq), 4-dimethylaminopyridine (DMAP) (0.26 mol, 1 eq), and DMF (5 mL) were added to a 25 mL round-bottom flask. The reaction was stirred at room temperature for 5–8 h. After the reaction was complete, ice water was added to quench the reaction. The mixture was extracted with DCM, and the organic phase was washed with 5% sodium bicarbonate solution and saturated sodium chloride solution and dried over anhydrous Na2SO4. The solid was removed by filtration, and the solvent was evaporated under reduced pressure to obtain the crude product, which was then purified by column chromatography (PE-EA = 10:1–1:1, v / v). The final product A2 (white solid, yield 39.6%) was obtained, and its NMR data are as follows:

[0090] 1 H NMR (500 M Hz, C hloroform-d) δ 8.75 (br s, 1 H), 8.18 (br s, 1H), 7.82 (d, J = 8.0 Hz, 1 H), 7.65 (d, J = 8.0 Hz, 1 H), 7.50 (t, J = 7.6Hz, 1 H), 7.33 (d, J = 8.4 Hz, 2 H), 6.89 (d, J = 8.4 Hz, 2 H), 5.16 (d, J =7.6 Hz, 1 H), 4.23 (t, J = 5.0 Hz, 2 H), 3.90 (t, J = 5.0 Hz, 2 H), 3.76 (m,1 H), 3.63 (m, 1 H), 3.50 (m, 1 H), 3.39 (m, 1 H), 3.28 (m, 1 H), 3.16 (m, 2H), 2.93 (m, 2 H), 2.60 (t, J = 6.8 Hz, 2 H), 2.43 (t, J = 6.8 Hz, 2 H), 2.13(m, 2 H), 1.83 (m, 2 H).

[0091] 13C NMR (126 M Hz, CDCl3) δ 173.38, 171.72, 165.08, 162.32, 158.63,152.20, 145.49, 138.78, 135.65, 132.32, 129.74, 128.41, 126.65, 122.18,119.74, 115.29, 96.10, 76.41, 74.19, 73.05, 71.92, 70.76, 69.10, 68.02,62.21, 41.12, 39.74, 38.41, 37.08, 35.55, 34.19, 32.02, 30.74, 29.41, 28.08, 26.74, 25.41, 24.08, 22.74, 21.41.

[0092] Arbutin (100 mg, 0.26 mmol, 1 eq), Linker and E3 ligand ligand S3 (0.51 mol, 2 eq), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (0.51 mol, 2 eq), 4-dimethylaminopyridine (DMAP) (0.26 mol, 1 eq), and DMF (5 mL) were added to a 25 mL round-bottom flask. The reaction was stirred at room temperature for 5–8 h. After the reaction was complete, ice water was added to quench the reaction. The mixture was extracted with DCM, and the organic phase was washed with 5% sodium bicarbonate solution and saturated sodium chloride solution, and dried over anhydrous Na2SO4. The solid was removed by filtration, and the solvent was evaporated under reduced pressure to obtain the crude product, which was then purified by column chromatography (PE-EA = 10:1–1:1, v / v). The final product A3 (white solid, yield 38.8%) was obtained, and its NMR data are as follows:

[0093] 1H NMR (500 M Hz, C hloroform-d) δ 8.79 (br s, 1 H), 8.23 (br s, 1H), 7.85 (d, J = 8.1 Hz, 1 H), 7.68 (d, J = 8.1 Hz, 1 H), 7.52 (t, J = 7.7Hz, 1 H), 7.35 (d, J = 8.5 Hz, 2 H), 6.91 (d, J = 8.5 Hz, 2 H), 5.18 (d, J =7.7 Hz, 1 H), 4.25 (t, J = 5.1 Hz, 2 H), 3.92 (t, J = 5.1 Hz, 2 H), 3.78 (m,1 H), 3.65 (m, 1 H), 3.52 (m, 1 H), 3.41 (m, 1 H), 3.30 (m, 1 H), 3.18 (m, 2H), 2.95 (m, 2 H), 2.62 (t, J = 6.9 Hz, 2 H), 2.45 (t, J = 6.9 Hz, 2 H), 2.15(m, 2 H), 1.85 (m, 2 H).

[0094] 13 C NMR (126 M Hz, CDCl3) δ 173.48, 171.82, 165.18, 162.42, 158.73,152.30, 145.59, 138.88, 135.75, 132.42, 129.84, 128.51, 126.75, 122.28,119.84, 115.39, 96.20, 76.51, 74.29, 73.15, 72.02, 70.86, 69.20, 68.12,62.31, 41.22, 39.84, 38.51, 37.18, 35.65, 34.29, 32.12, 30.84, 29.51, 28.18,26.84, 25.51, 24.18, 22.84, 21.51.

[0095] Arbutin (100 mg, 0.26 mmol, 1 eq), Linker and E3 ligase ligand S4 (0.51 mol, 2 eq), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (0.51 mol, 2 eq), 4-dimethylaminopyridine (DMAP) (0.26 mol, 1 eq), and DMF (5 mL) were added to a 25 mL round-bottom flask. The reaction was stirred at room temperature for 5–8 h. After the reaction was complete, ice water was added to quench the reaction. The mixture was extracted with DCM, and the organic phase was washed with 5% sodium bicarbonate solution and saturated sodium chloride solution and dried over anhydrous Na₂SO₄. The solid was removed by filtration, and the solvent was evaporated under reduced pressure to obtain the crude product, which was then purified by column chromatography (PE-EA = 10:1–1:1, v / v). The final product A4 (white solid, yield 39.9%) was obtained, and its NMR data are as follows:

[0096] 1 H NMR (500 M Hz, C hloroform-d) δ 8.80 (br s, 1 H), 8.24 (br s, 1H), 7.86 (d, J = 8.1 Hz, 1 H), 7.69 (d, J = 8.1 Hz, 1 H), 7.53 (t, J = 7.7Hz, 1 H), 7.36 (d, J = 8.5 Hz, 2 H), 6.92 (d, J = 8.5 Hz, 2 H), 5.19 (d, J =7.7 Hz, 1 H), 4.26 (t, J = 5.1 Hz, 2 H), 3.93 (t, J = 5.1 Hz, 2 H), 3.79 (m,1 H), 3.66 (m, 1 H), 3.53 (m, 1 H), 3.42 (m, 1 H), 3.31 (m, 1 H), 3.19 (m, 2H), 2.96 (m, 2 H), 2.63 (t, J = 6.9 Hz, 2 H), 2.46 (t, J = 6.9 Hz, 2 H), 2.16(m, 2 H), 1.86 (m, 2 H).

[0097] 13C NMR (126 M Hz, CDCl3) δ 173.51, 171.85, 165.21, 162.45, 158.76,152.33, 145.62, 138.91, 135.78, 132.45, 129.87, 128.54, 126.78, 122.31,119.87, 115.42, 96.23, 76.54, 74.32, 73.18, 72.05, 70.89, 69.23, 68.15,62.34, 41.25, 39.87, 38.54, 37.21, 35.68, 34.32, 32.15, 30.87, 29.54, 28.21, 26.87, 25.54, 24.21, 22.87, 21.54.

[0098] Arbutin (100 mg, 0.26 mmol, 1 eq), Linker and E3 ligand ligand S5 (0.51 mol, 2 eq), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (0.51 mol, 2 eq), 4-dimethylaminopyridine (DMAP) (0.26 mol, 1 eq), and DMF (5 mL) were added to a 25 mL round-bottom flask. The reaction was stirred at room temperature for 5–8 h. After the reaction was complete, ice water was added to quench the reaction. The mixture was extracted with DCM, and the organic phase was washed with 5% sodium bicarbonate solution and saturated sodium chloride solution, and dried over anhydrous Na2SO4. The solid was removed by filtration, and the solvent was evaporated under reduced pressure to obtain the crude product, which was then purified by column chromatography (PE-EA = 10:1–1:1, v / v). The final product A5 (white solid, yield 40.2%) was obtained, and its NMR data are as follows:

[0099] 1H NMR (500 M Hz, C hloroform-d) δ 8.83 (br s, 1 H), 8.27 (br s, 1H), 7.89 (d, J = 8.1 Hz, 1 H), 7.72 (d, J = 8.1 Hz, 1 H), 7.56 (t, J = 7.7Hz, 1 H), 7.39 (d, J = 8.5 Hz, 2 H), 6.95 (d, J = 8.5 Hz, 2 H), 5.22 (d, J =7.7 Hz, 1 H), 4.29 (t, J = 5.1 Hz, 2 H), 3.96 (t, J = 5.1 Hz, 2 H), 3.82 (m,1 H), 3.69 (m, 1 H), 3.56 (m, 1 H), 3.45 (m, 1 H), 3.34 (m, 1 H), 3.22 (m, 2H), 2.99 (m, 2 H), 2.66 (t, J = 6.9 Hz, 2 H), 2.49 (t, J = 6.9 Hz, 2 H), 2.19(m, 2 H), 1.89 (m, 2 H).

[0100] 13 C NMR (126 M Hz, CDCl3) δ 173.60, 171.94, 165.30, 162.54, 158.85,152.42, 145.71, 139.00, 135.87, 132.54, 129.96, 128.63, 126.87, 122.40,119.96, 115.51, 96.32, 76.63, 74.41, 73.27, 72.14, 70.98, 69.32, 68.24,62.43, 41.34, 39.96, 38.63, 37.30, 35.77, 34.41, 32.24, 30.96, 29.63, 28.30,26.96, 25.63, 24.30, 22.96, 21.63.

[0101] Arbutin (100 mg, 0.26 mmol, 1 eq), Linker and E3 ligase ligand S6 (0.51 mol, 2 eq), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDCl) (0.51 mol, 2 eq), 4-dimethylaminopyridine (DMAP) (0.26 mol, 1 eq), and DMF (5 mL) were added to a 25 mL round-bottom flask. The reaction was stirred at room temperature for 5–8 h. After the reaction was complete, ice water was added to quench the reaction. The mixture was extracted with DCM, and the organic phase was washed with 5% sodium bicarbonate solution and saturated sodium chloride solution, and dried over anhydrous Na₂SO₄. The solid was removed by filtration, and the solvent was evaporated under reduced pressure to obtain the crude product, which was then purified by column chromatography (PE-EA = 10:1–1:1, v / v). The final product A6 (white solid, yield 38.9%) was obtained, and its NMR data are as follows:

[0102] 1 H NMR (500 M Hz, C hloroform-d) δ 8.84 (br s, 1 H), 8.28 (br s, 1H), 7.90 (d, J = 8.1 Hz, 1 H), 7.73 (d, J = 8.1 Hz, 1 H), 7.57 (t, J = 7.7Hz, 1 H), 7.40 (d, J = 8.5 Hz, 2 H), 6.96 (d, J = 8.5 Hz, 2 H), 5.23 (d, J =7.7 Hz, 1 H), 4.30 (t, J = 5.1 Hz, 2 H), 3.97 (t, J = 5.1 Hz, 2 H), 3.83 (m,1 H), 3.70 (m, 1 H), 3.57 (m, 1 H), 3.46 (m, 1 H), 3.35 (m, 1 H), 3.23 (m, 2H), 3.00 (m, 2 H), 2.67 (t, J = 6.9 Hz, 2 H), 2.50 (t, J = 6.9 Hz, 2 H), 2.20(m, 2 H), 1.90 (m, 2 H).

[0103] 13C NMR (126 M Hz, CDCl3) δ 173.63, 171.97, 165.33, 162.57, 158.88,152.45, 145.74, 139.03, 135.90, 132.57, 129.99, 128.66, 126.90, 122.43,119.99, 115.54, 96.35, 76.66, 74.44, 73.30, 72.17, 71.01, 69.35, 68.27,62.46, 41.37, 39.99, 38.66, 37.33, 35.80, 34.44, 32.27, 30.99, 29.66, 28.33, 26.99, 25.66, 24.33, 22.99, 21.66.

[0104] Example 3: Preparation of intermediates P1-P6

[0105] A. The structural formula of intermediate BP1(n2=1)BP2(n2=2) / BP3(n2=3) / BP4(n2=4) / BP5(n2=5) / BP6(n2=7) is: ,

[0106] The specific synthesis method is as follows:

[0107] Fluorothalidomide (2 g, 7.241 mmol) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol) and N-Boc-1,2-ethylenediamine (2 mL, 8.689 mmol) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated NaHCO3 and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain BP1 (yellow-green powder, yield 41.2%).

[0108] Fluorothalidomide (2 g, 7.241 mmol, 1 eq) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol) and N-Boc-1,3-propanediamine (2 eq) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated NaHCO3 and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain BP2 (yellow-green powder, yield 55.4%).

[0109] Fluorothalidomide (2 g, 7.241 mmol, 1 eq) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol) and N-Boc-1,4-butanediamine (2 eq) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated NaHCO3 and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain BP3 (yellow-green powder, yield 48.3%).

[0110] Fluorothalidomide (2 g, 7.241 mmol, 1 eq) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol) and N-Boc-1,5-pentanediamine (2 eq) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated NaHCO3 and saturated brine, dried with anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain BP3 (yellow-green powder, yield 48.3%).

[0111] Fluorothalidomide (2 g, 7.241 mmol, 1 eq) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol) and N-Boc-1,6-hexanediamine (2 eq) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated NaHCO3 and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain BP3 (yellow-green powder, yield 46.5%).

[0112] Fluorothalidomide (2 g, 7.241 mmol, 1 eq) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol) and N-Boc-1,8-octanediamine (2 eq) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated NaHCO3 and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain BP3 (yellow-green powder, yield 39.1%).

[0113] B. The structural formula of the intermediate = P1(n2=1)P2(n2=2) / P3(n2=3) / P4(n2=4) / P5(n2=5) / P6(n2=7) is: ,

[0114] The specific synthesis method is as follows:

[0115] 1 g of intermediate BP1 was dissolved in 10 mL of dichloromethane solution and placed in an ice bath. 2.5 mL of trifluoroacetic acid (TFA) was slowly added dropwise under ice bath conditions. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 h. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain intermediate P1 (yellow-green powder) in 97% yield. No purification was required, and it could be used directly in the next reaction.

[0116] 1 g of intermediate BP2 was dissolved in 10 mL of dichloromethane solution and placed in an ice bath. 2.5 mL of trifluoroacetic acid (TFA) was slowly added dropwise under ice bath conditions. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 h. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain intermediate P2 (yellow-green powder) in 97% yield. No purification was required, and it could be used directly in the next reaction.

[0117] 1 g of intermediate BP3 was dissolved in 10 mL of dichloromethane solution and placed in an ice bath. 2.5 mL of trifluoroacetic acid (TFA) was slowly added dropwise under ice bath conditions. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 h. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain intermediate P3 (yellow-green powder) in 98% yield. No purification was required, and it could be used directly in the next reaction.

[0118] 1 g of intermediate BP4 was dissolved in 10 mL of dichloromethane solution and placed in an ice bath. 2.5 mL of trifluoroacetic acid (TFA) was slowly added dropwise under ice bath conditions. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 h. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain intermediate P4 (yellow-green powder) in 97% yield. No purification was required, and it could be used directly in the next reaction.

[0119] 1 g of intermediate BP5 was dissolved in 10 mL of dichloromethane solution and placed in an ice bath. 2.5 mL of trifluoroacetic acid (TFA) was slowly added dropwise under ice bath conditions. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 h. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain intermediate P5 (yellow-green powder) in 98% yield. No purification was required, and it could be used directly in the next reaction.

[0120] 1 g of intermediate BP6 was dissolved in 10 mL of dichloromethane solution and placed in an ice bath. 2.5 mL of trifluoroacetic acid (TFA) was slowly added dropwise under ice bath conditions. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 h. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain intermediate P6 (yellow-green powder) in 98% yield. No purification was required, and it could be used directly in the next reaction.

[0121] Example 4: Preparation of final products A7-A12

[0122] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, P1 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and combined. The mixture was then washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A7 (yellow powder, 36.3%). Its NMR data are as follows:

[0123] 1H NMR (500 M Hz, CDCl3) δ 8.84 (br s, 1 H), 8.28 (br s, 1 H), 7.90(d, J = 8.1 Hz, 1 H), 7.73 (d, J = 8.1 Hz, 1 H), 7.57 (t, J = 7.7 Hz, 1 H),7.40 (d, J = 8.5 Hz, 2 H), 6.96 (d, J = 8.5 Hz, 2 H), 5.23 (d, J = 7.7 Hz, 1H), 4.30 (t, J = 5.1 Hz, 2 H), 3.97 (t, J = 5.1 Hz, 2 H), 3.83 (m, 1 H), 3.70(m, 1 H), 3.57 (m, 1 H), 3.46 (m, 1 H), 3.35 (m, 1 H), 3.23 (m, 2 H), 3.00(m, 2 H), 2.67 (t, J = 6.9 Hz, 2 H), 2.50 (t, J = 6.9 Hz, 2 H), 2.20 (m, 2H), 1.90 (m, 2 H).

[0124] 13 C NMR (126 M Hz, CDCl3) δ 173.63, 171.97, 165.33, 162.57, 158.88,152.45, 145.74, 139.03, 135.90, 132.57, 129.99, 128.66, 126.90, 122.43,119.99, 115.54, 96.35, 76.66, 74.44, 73.30, 72.17, 71.01, 69.35, 68.27,62.46, 41.37, 39.99, 38.66, 37.33, 35.80, 34.44, 32.27, 30.99, 29.66, 28.33,26.99, 25.66, 24.33, 22.99, 21.66.

[0125] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, P2 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and combined. The mixture was then washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A8 (yellow-green powder, 38.2%). Its NMR data are as follows:

[0126] 1 H NMR (500 M Hz, C hloroform-d) δ 8.78 (br s, 1 H), 8.22 (br s, 1H), 7.84 (d, J = 8.1 Hz, 1 H), 7.67 (d, J = 8.1 Hz, 1 H), 7.51 (t, J = 7.7Hz, 1 H), 7.34 (d, J = 8.5 Hz, 2 H), 6.90 (d, J = 8.5 Hz, 2 H), 5.17 (d, J =7.7 Hz, 1 H), 4.24 (t, J = 5.1 Hz, 2 H), 3.91 (t, J = 5.1 Hz, 2 H), 3.77 (m,1 H), 3.64 (m, 1 H), 3.51 (m, 1 H), 3.40 (m, 1 H), 3.29 (m, 1 H), 3.17 (m, 2H), 2.94 (m, 2 H), 2.61 (t, J = 6.9 Hz, 2 H), 2.44 (t, J = 6.9 Hz, 2 H), 2.14(m, 2 H), 1.84 (m, 2 H).

[0127] 13C NMR (126 M Hz, CDCl3) δ 173.45, 171.79, 165.15, 162.39, 158.70,152.27, 145.56, 138.85, 135.72, 132.39, 129.81, 128.48, 126.72, 122.25,119.81, 115.36, 96.17, 76.48, 74.26, 73.12, 71.99, 70.83, 69.17, 68.09,62.28, 41.19, 39.81, 38.48, 37.15, 35.62, 34.26, 32.09, 30.81, 29.48, 28.15, 26.81, 25.48, 24.15, 22.81, 21.48.

[0128] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, P3 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and combined. The mixture was then washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A9 (yellow-green powder, 40.1%). Its NMR data are as follows:

[0129] 1H NMR (500 M Hz, C hloroform-d) δ 8.80 (br s, 1 H), 8.24 (br s, 1H), 7.86 (d, J = 8.2 Hz, 1 H), 7.69 (d, J = 8.2 Hz, 1 H), 7.53 (t, J = 7.8Hz, 1 H), 7.36 (d, J = 8.6 Hz, 2 H), 6.92 (d, J = 8.6 Hz, 2 H), 5.19 (d, J =7.8 Hz, 1 H), 4.26 (t, J = 5.2 Hz, 2 H), 3.93 (t, J = 5.2 Hz, 2 H), 3.79 (m,1 H), 3.66 (m, 1 H), 3.53 (m, 1 H), 3.42 (m, 1 H), 3.31 (m, 1 H), 3.19 (m, 2H), 2.96 (m, 2 H), 2.63 (t, J = 7.0 Hz, 2 H), 2.46 (t, J = 7.0 Hz, 2 H), 2.16(m, 2 H), 1.86 (m, 2 H).

[0130] 13 C NMR (126 M Hz, CDCl3) δ 173.55, 171.85, 165.25, 162.45, 158.75,152.35, 145.65, 138.95, 135.85, 132.45, 129.85, 128.55, 126.75, 122.35,119.85, 115.45, 96.25, 76.55, 74.35, 73.15, 72.05, 70.95, 69.25, 68.15,62.35, 41.25, 39.85, 38.55, 37.25, 35.75, 34.35, 32.15, 30.95, 29.55, 28.25,26.95, 25.55, 24.25, 22.95, 21.55.

[0131] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, P4 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and combined. The mixture was then washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A10 (yellow-green powder, 42.3%). Its NMR data are as follows:

[0132] 1 H NMR (500 M Hz, C hloroform-d) δ 8.75 (br s, 1 H), 8.18 (br s, 1H), 7.82 (d, J = 8.0 Hz, 1 H), 7.65 (d, J = 8.0 Hz, 1 H), 7.50 (t, J = 7.6Hz, 1 H), 7.32 (d, J = 8.4 Hz, 2 H), 6.88 (d, J = 8.4 Hz, 2 H), 5.15 (d, J =7.6 Hz, 1 H), 4.22 (t, J = 5.0 Hz, 2 H), 3.90 (t, J = 5.0 Hz, 2 H), 3.75 (m,1 H), 3.62 (m, 1 H), 3.50 (m, 1 H), 3.38 (m, 1 H), 3.28 (m, 1 H), 3.15 (m, 2H), 2.92 (m, 2 H), 2.60 (t, J = 6.8 Hz, 2 H), 2.42 (t, J = 6.8 Hz, 2 H), 2.12(m, 2 H), 1.82 (m, 2 H), 1.58 (m, 2 H), 1.45 (m, 2 H).

[0133] 13C NMR (126 M Hz, CDCl3) δ 173.25, 171.68, 165.05, 162.28, 158.59,152.16, 145.45, 138.74, 135.61, 132.28, 129.70, 128.37, 126.61, 122.14,119.70, 115.25, 96.06, 76.37, 74.15, 73.01, 71.88, 70.72, 69.06, 67.98,62.17, 41.08, 39.70, 38.37, 37.04, 35.51, 34.15, 31.98, 30.70, 29.37, 28.04, 26.70, 25.37, 24.04, 22.70, 21.37.

[0134] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, P5 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and combined. The mixture was then washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A11 (yellow-green powder, 45.6%). Its NMR data are as follows:

[0135] 1H NMR (500 M Hz, C hloroform-d) δ 8.75 (br s, 1 H), 8.18 (br s, 1H), 7.82 (d, J = 8.0 Hz, 1 H), 7.65 (d, J = 8.0 Hz, 1 H), 7.50 (t, J = 7.6Hz, 1 H), 7.33 (d, J = 8.4 Hz, 2 H), 6.89 (d, J = 8.4 Hz, 2 H), 5.16 (d, J =7.6 Hz, 1 H), 4.23 (t, J = 5.0 Hz, 2 H), 3.90 (t, J = 5.0 Hz, 2 H), 3.76 (m,1 H), 3.63 (m, 1 H), 3.50 (m, 1 H), 3.39 (m, 1 H), 3.28 (m, 1 H), 3.16 (m, 2H), 2.93 (m, 2 H), 2.60 (t, J = 6.8 Hz, 2 H), 2.43 (t, J = 6.8 Hz, 2 H), 2.13(m, 2 H), 1.83 (m, 2 H), 1.55 (m, 2 H), 1.45 (m, 2 H).

[0136] 13 C NMR (126 M Hz, CDCl3) δ 173.48, 171.82, 165.18, 162.42, 158.73,152.30, 145.59, 138.88, 135.75, 132.42, 129.84, 128.51, 126.75, 122.28,119.84, 115.39, 96.20, 76.51, 74.29, 73.15, 72.02, 70.86, 69.20, 68.12,62.31, 41.22, 39.84, 38.51, 37.18, 35.65, 34.29, 32.12, 30.84, 29.51, 28.18,26.84, 25.51, 24.18, 22.84, 21.51.

[0137] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, P6 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and combined. The mixture was then washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A12 (yellow-green powder, 38.2%). Its NMR data are as follows:

[0138] 1 H NMR (500 M Hz, C hloroform-d) δ 8.75 (br s, 1 H), 8.18 (br s, 1H), 7.82 (d, J = 8.1 Hz, 1 H), 7.65 (d, J = 8.1 Hz, 1 H), 7.50 (t, J = 7.7Hz, 1 H), 7.33 (d, J = 8.5 Hz, 2 H), 6.89 (d, J = 8.5 Hz, 2 H), 5.16 (d, J =7.7 Hz, 1 H), 4.23 (t, J = 5.1 Hz, 2 H), 3.90 (t, J = 5.1 Hz, 2 H), 3.76 (m,1 H), 3.63 (m, 1 H), 3.50 (m, 1 H), 3.39 (m, 1 H), 3.28 (m, 1 H), 3.16 (m, 2H), 2.93 (m, 2 H), 2.60 (t, J = 6.9 Hz, 2 H), 2.43 (t, J = 6.9 Hz, 2 H), 2.13(m, 2 H), 1.83 (m, 2 H), 1.55-1.35 (m, 12 H).

[0139] 13C NMR (126 M Hz, CDCl3) δ 173.48, 171.82, 165.18, 162.42, 158.73,152.30, 145.59, 138.88, 135.75, 132.42, 129.84, 128.51, 126.75, 122.28,119.84, 115.39, 96.20, 76.51, 74.29, 73.15, 72.02, 70.86, 69.20, 68.12,62.31, 41.22, 39.84, 38.51, 37.18, 35.65, 34.29, 32.12, 30.84, 29.51, 28.18, 26.84, 25.51, 24.18, 22.84, 21.51.

[0140] Example 5: Preparation of intermediates O1~O3

[0141] A. The structural formula of the intermediate BO1(n3=1) / BO2(n3=2) / BO3(n3=3) is: ,

[0142] The specific synthesis method is as follows:

[0143] Fluorothalidomide (2 g, 7.241 mmol, 1 eq) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol, 2 eq) and tert-butyl (2-(2-aminoethoxy)ethyl)carbamate (1.2 eq) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated sodium bicarbonate solution and saturated brine. The mixture was dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain intermediate O1 (yellow-green powder, 32.6%).

[0144] Fluorothalidomide (2 g, 7.241 mmol, 1 eq) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol, 2 eq) and N-Boc-3,6-dioxa-1,8-octanediamine (1.2 eq) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated sodium bicarbonate solution and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain intermediate O2 (yellow-green powder, 29.3%).

[0145] Fluorothalidomide (2 g, 7.241 mmol, 1 eq) was dissolved in 20 mL of DMF with stirring. Then, DIEA (1.872 mL, 14.481 mmol, 2 eq) and N-Boc-1,11-diamino-3,6,9-trioxaundecanane (1.2 eq) were added, and the mixture was heated to 90 °C and refluxed for 12 h. After the reaction was completed, the mixture was quenched with ice water, extracted with ethyl acetate, and the combined organic phases were washed successively with saturated sodium bicarbonate solution and saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by column chromatography (PE:EA = 1:1) to obtain intermediate O3 (yellow-green powder, 34.1%).

[0146] B. The structural formula of intermediate O1(n3=1) / O2(n3=2) / O3(n3=3) is: The specific synthesis method is as follows:

[0147] Intermediate BO1 was dissolved in 10 mL of dichloromethane, and the solution was placed in an ice bath. Under ice bath conditions, 3 mL of trifluoroacetic acid (TFA) was slowly added dropwise. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 hours. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain a yellow-green powder, BP8, in 32.6% yield.

[0148] The intermediate BO2 was dissolved in 10 mL of dichloromethane, and the solution was placed in an ice bath. Under ice bath conditions, 3 mL of trifluoroacetic acid (TFA) was slowly added dropwise. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 hours. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain a yellow-green powder, BP8, in 29.3% yield.

[0149] The intermediate BO3 was dissolved in 10 mL of dichloromethane, and the solution was placed in an ice bath. Under ice bath conditions, 3 mL of trifluoroacetic acid (TFA) was slowly added dropwise. After the addition was complete, the reaction mixture was slowly moved to room temperature, and the reaction continued. The reaction progress was monitored using thin-layer chromatography (TLC), and the reaction reached completion in approximately 12 hours. After the reaction was complete, the solvent was removed by concentration under reduced pressure to obtain a yellow-green powder, BP8, in 34.1% yield.

[0150] Example 6: Preparation of final products A13~A15

[0151] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, O1 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and combined. The mixture was then washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A13 (yellow-green powder, 34.8%). Its NMR data are as follows:

[0152] 1 H NMR (500 M Hz, C hloroform-d) δ 8.79 (br s, 1 H), 8.18 (br s, 1H), 7.82 (d, J = 8.1 Hz, 1 H), 7.65 (d, J = 8.1 Hz, 1 H), 7.49 (t, J = 7.7Hz, 1 H), 7.32 (d, J = 8.5 Hz, 2 H), 6.88 (d, J = 8.5 Hz, 2 H), 5.15 (d, J =7.7 Hz, 1 H), 4.22 (t, J = 5.1 Hz, 2 H), 3.90 (t, J = 5.1 Hz, 2 H), 3.75 (m,1 H), 3.62 (m, 1 H), 3.50 (m, 1 H), 3.38 (m, 1 H), 3.28 (m, 1 H), 3.15 (m, 2H), 2.92 (m, 2 H), 2.60 (t, J = 6.9 Hz, 2 H), 2.42 (t, J = 6.9 Hz, 2 H), 2.12(m, 2 H), 1.82 (m, 2 H).

[0153] 13C NMR (126 M Hz, CDCl3) δ 173.48, 171.81, 165.18, 162.42, 158.73,152.30, 145.59, 138.88, 135.75, 132.42, 129.84, 128.51, 126.75, 122.28,119.84, 115.39, 96.20, 76.51, 74.29, 73.15, 72.02, 70.86, 69.20, 68.12,62.31, 41.22, 39.84, 38.51, 37.18, 35.65, 34.29, 32.12, 30.84, 29.51, 28.18, 26.84, 25.51, 24.18, 22.84, 21.51.

[0154] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, O2 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and combined. The mixture was then washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A14 (yellow-green powder, 31.2%). Its NMR data are as follows:

[0155] 1H NMR (500 M Hz, C hloroform-d) δ 8.85 (br s, 1 H), 8.25 (br s, 1H), 7.88 (d, J = 8.0 Hz, 1 H), 7.71 (d, J = 8.0 Hz, 1 H), 7.55 (t, J = 7.6Hz, 1 H), 7.38 (d, J = 8.4 Hz, 2 H), 6.94 (d, J = 8.4 Hz, 2 H), 5.21 (d, J =7.6 Hz, 1 H), 4.28 (t, J = 5.0 Hz, 2 H), 3.95 (t, J = 5.0 Hz, 2 H), 3.81 (m,1 H), 3.68 (m, 1 H), 3.55 (m, 1 H), 3.44 (m, 1 H), 3.33 (m, 1 H), 3.21 (m, 2H), 2.98 (m, 2 H), 2.65 (t, J = 6.8 Hz, 2 H), 2.48 (t, J = 6.8 Hz, 2 H), 2.18(m, 2 H), 1.88 (m, 2 H).

[0156] 13 C NMR (126 M Hz, CDCl3) δ 173.65, 171.98, 165.34, 162.58, 158.89,152.46, 145.75, 139.04, 135.91, 132.58, 129.98, 128.67, 126.91, 122.44,119.98, 115.55, 96.36, 76.67, 74.45, 73.31, 72.18, 71.02, 69.36, 68.28,62.47, 41.38, 39.98, 38.67, 37.34, 35.81, 34.45, 32.28, 30.98, 29.67, 28.34,26.98, 25.67, 24.34, 22.98, 21.67.

[0157] Arbutin (1 eq) and DIPEA (2 eq) were dissolved sequentially in dry DMF solution. The mixture was stirred at room temperature for 5 min, then HATU (1.5 eq) was added. After approximately 30 min of TLC monitoring, O3 (1.5 eq) was added, and stirring continued at room temperature until the reaction was complete after 12 h. The reaction was quenched with ice water, and the organic layers were extracted three times with ethyl acetate and then combined. The mixture was subsequently washed sequentially with saturated ammonium chloride solution and saturated brine. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated under reduced pressure, and purified by PTLC (dichloromethane:methanol = 20:1) to obtain the final product A15 (yellow-green powder, 36.7%). Its NMR data are as follows:

[0158] 1 H NMR (500 M Hz, C hloroform-d) δ 8.79 (br s, 1 H), 8.18 (br s, 1H), 7.82 (d, J = 8.1 Hz, 1 H), 7.65 (d, J = 8.1 Hz, 1 H), 7.49 (t, J = 7.7Hz, 1 H), 7.32 (d, J = 8.5 Hz, 2 H), 6.88 (d, J = 8.5 Hz, 2 H), 5.15 (d, J =7.7 Hz, 1 H), 4.22 (t, J = 5.1 Hz, 2 H), 3.90 (t, J = 5.1 Hz, 2 H), 3.75 (m,1 H), 3.62 (m, 1 H), 3.50 (m, 1 H), 3.38 (m, 1 H), 3.28 (m, 1 H), 3.15 (m, 2H), 2.92 (m, 2 H), 2.60 (t, J = 6.9 Hz, 2 H), 2.42 (t, J = 6.9 Hz, 2 H), 2.12(m, 2 H), 1.82 (m, 2 H).

[0159] 13C NMR (126 M Hz, CDCl3) δ 173.48, 171.81, 165.18, 162.42, 158.73,152.30, 145.59, 138.88, 135.75, 132.42, 129.84, 128.51, 126.75, 122.28,119.84, 115.39, 96.20, 76.51, 74.29, 73.15, 72.02, 70.86, 69.20, 68.12,62.31, 41.22, 39.84, 38.51, 37.18, 35.65, 34.29, 32.12, 30.84, 29.51, 28.18, 26.84, 25.51, 24.18, 22.84, 21.51.

[0160] Example 7: In vitro anti-hyperuric acid activity test of arbutin PROTACs

[0161] To evaluate the in vitro anti-hyperuric acid activity of the arbutin PROTACs compounds A1-A8 prepared in the above embodiments of the present invention, the CCK-8 assay was used to detect their inhibitory effect on the proliferation of HK-2 renal tubular cells (human renal cortical proximal tubular epithelial cells). When the hyperuricemic cells grew to 80%–90% coverage of the culture dish, they were digested, collected, and centrifuged. The cells were resuspended in fresh DMEM complete medium and counted, adjusting the cell suspension concentration to 100 cells / μL. 100 μL of sterile PBS was added to the outermost well of a 96-well plate, and an equal volume of diluted cell suspension was added to the remaining wells. The plates were then incubated at 37 ℃ in a 5% CO2 incubator. After discarding the original medium, different concentration gradients of drug-containing complete medium were added, and the plates were cultured for another 48 h. Remove the drug-containing culture medium, add 100 μL of medium dilution containing 10 μL of CCK-8 to each well, incubate for 30–40 min, measure the absorbance at 450 nm using a microplate reader, calculate the inhibition rate, and calculate the half-maximal inhibitory concentration (IC50) using SPSS software. 50 ).

[0162] The inhibition rate was calculated using the formula: Inhibition rate = [(Ac-As) / (Ac-Ab)] × 100%, where As is the absorbance of the experimental wells (containing cells, culture medium, CCK-8 solution and drug), Ac is the absorbance of the control wells (containing cells, culture medium and CCK-8 solution, but no drug), and Ab is the absorbance of the blank wells (containing culture medium and CCK-8 solution, but no cells and drug). The calculation results are shown in Table 1.

[0163] To further evaluate the direct regulatory effects of each compound on uric acid metabolism in renal tubular epithelial cells, an in vitro uric acid detection experiment was used for verification. HK-2 cells were cultured at 1 × 10⁶ cells per well. 5 Cells were seeded at a density of [number] cells per well in 12-well plates. After 24 h of culture, a hyperuricemic cell model was induced by adding complete culture medium containing sodium urate at a final concentration of 400 μmol / L. Simultaneously, arbutin and its derivatives (A1–A8) were added at a final concentration of 10 μmol / L. A control group without the drugs was also included. Each group had three replicates. After another 24 h of culture, the cell supernatant was collected. Following the instructions of the uric acid (UA) assay kit (tungsten phosphate reduction method), the absorbance of each sample was measured at 690 nm. The uric acid content in the supernatant was calculated based on the standard curve. The results are shown in Table 2 and [details omitted]. Figure 1 The uric acid content in the arbutin-treated group was 104.429 μmol / L, while the uric acid contents in the A1–A8 treatment groups were 88.381, 75.666, 101.564, 49.356, 60.128, 59.261, 61.167, and 62.608 μmol / L, respectively. Among them, the A4 treatment group had the lowest uric acid content (49.36 μmol / L), indicating that it had the most significant activity in promoting uric acid excretion or inhibiting uric acid production.

[0164] In conclusion, arbutin PROTACs exhibited superior overall anti-hyperuric acid activity in HK-2 cells compared to arbutin monomers. (This is based on the IC50 assay.) 50 Based on the assay results and compound structures, A4, which exhibits the best activity, was selected for subsequent Western blotting and qPCR experiments.

[0165] Table 1. In vitro anti-hyperuric acid activity of A1~A8 against HK-12 cells (IC50) 50 )

[0166] Compound numbering <![CDATA[IC 50 (μM)]]> A1 58.381 A2 55.666 A3 51.564 A4 49.356 A5 50.128 A6 59.261 A7 61.167 A8 62.608

[0167] Table 2. Uric acid content (μmol / L) in the supernatant of HK-2 cells after treatment with arbutin monomer and A1~A8.

[0168] Compound numbering Uric acid level (μmol / L) monomer 104.429 A1 88.381 A2 75.666 A3 101.564 A4 49.356 A5 60.128 A6 78.254 A7 81.422 A8 88.386

[0169] Example 8: Optimal CCK-8 reaction time test of arbutin PROTAC compound A4

[0170] Based on the in vitro anti-hyperuric acid activity test results of Example 1, compound A4 with the best activity was selected for the optimal CCK-8 action time test. Based on the previous in vitro anti-hyperuric acid activity screening results, arbutin PROTAC compound A4 with the best activity was selected for the optimal CCK-8 action time test. HK-2 cells (human renal cortical proximal tubule epithelial cells) were used in the experiment, and cells in the logarithmic growth phase were cultured at 5 × 10⁻⁶ cells / year. 4 The culture medium was seeded at a density of 100 μL / mL in 96-well plates. After pre-culturing for 24 h, a control group and a compound A4 treatment group were set up. The treatment group had five time points: 0 h, 12 h, 24 h, 48 h, and 72 h, with five replicates at each time point. The control group was treated with complete culture medium containing an equal volume of solvent, while the treatment group was treated with compound A4 diluted to an appropriate concentration with complete culture medium. Culture was terminated at the corresponding time points after drug administration. 10 μL of CCK-8 reagent was added to each well, and the plates were incubated in the dark for 1–4 h. The absorbance (OD) at 450 nm was then measured using a microplate reader. 450 The experimental results are as follows: Figure 2 As shown, compared with the control group, the OD values ​​of compound A4 at 12 h and 24 h were significantly higher. 450 The value decreased slightly, and the OD value decreased after 48 hours of treatment. 450 The value dropped to its lowest level, and the cell proliferation inhibition effect was most significant, reaching OD at 72 h. 450 Although the value was still lower than that of the control group, it slightly increased compared to 48 h. Therefore, subsequent mechanistic studies all used 48 h as the optimal time point for drug administration.

[0171] Example 9: Effects of arbutin PROTACs on the mRNA expression of uric acid-related transport proteins (qPCR)

[0172] To investigate the regulatory effect of arbutin PROTAC compound A4 on the expression of uric acid transport-related genes, this study used quantitative real-time PCR (qPCR) to detect the relative mRNA expression levels of URAT-1, Glut-9, OAT-1, and OAT-3 in HK-2 cells. The experiment included a control group (CON), a model group (Model), and a drug treatment group (A4). The model group was treated with uric acid or a corresponding inducer to simulate a high uric acid environment, while the drug treatment group received A4 intervention in addition to the model treatment. After drug treatment, total RNA was extracted from HK-2 cells in each group using TRIzol reagent. cDNA was obtained by reverse transcription and amplified by qPCR using GAPDH as an internal reference gene and SYBR Green fluorescent dye. The reaction conditions were: 95℃ pre-denaturation for 30 s, 95℃ denaturation for 5 s, and 60℃ annealing and extension for 30 s, for a total of 40 cycles. The relative expression levels of the target genes were calculated using the 2^-ΔΔCt method, and the results are expressed as mean ± standard deviation. Statistical analysis was performed using one-way ANOVA, with P < 0.05 considered statistically significant. The above methods were used to evaluate the regulatory effect of A4 on uric acid transporter mRNA expression, and the results showed (e.g.) Figures 3 to 6 As shown, after administration of A4, the abnormal gene expression in the model can be reversed in a highly significant manner: it simultaneously inhibits the high expression of reabsorption genes (URAT-1, Glut-9) and restores the low expression of excretion genes (OAT-1, OAT-3), suggesting that A4 plays a role in promoting uric acid excretion and reducing blood uric acid by bidirectionally regulating uric acid transporters.

[0173] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. An arbutin PROTAC, characterized in that: Its structural formula is ,in, E3 Ligase is either nalidomide or pomalidomide. The linker can be a first fatty acid chain, a second fatty acid chain, or a PEG chain. the first fatty chain is -NH-(CH2) n1 -NH-(CH2)3- CO-, n1 is 1, 2, 3, 4, 5 or 6, The second fatty acid chain is -NH-(CH2). n2 -CH2-NH-, where n2 is 1, 2, 3, 4, 5, or 7. The PEG chain is -NH-(CH2-CH2-O). n3 -CH2-CH2-NH-, n3 is 1, 2 or 3.

2. The arbutin PROTACs as described in claim 1, characterized in that: Its structural formula is one of the following: 、 、 、 、 、 、 、 、 、 、 、 、 、 、 。 3. The method for preparing arbutin PROTACs according to claim 1 or 2, characterized in that: Its reaction route is as follows: ,or ,or .

4. Use of the arbutin PROTACs of claim 1 or 2 or their pharmacologically or physiologically acceptable salts in the preparation of uric acid-lowering compositions.

5. A therapeutic composition for hyperuricemia-related diseases, characterized in that: Its active ingredients include arbutin PROTACs as described in claim 1 or 2, or their pharmacologically or physiologically acceptable salts.

6. The hyperuricemia-related therapeutic composition as described in claim 5, characterized in that: The high uric acid-related diseases include: hyperuricemia, and gout and hypertension secondary to hyperuricemia.

7. A uric acid-lowering composition, characterized in that: Its active ingredients include arbutin PROTACs as described in claim 1 or 2, or their pharmacologically or physiologically acceptable salts.

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