A ferulic acid derivative based on protein targeted degradation chimera and its preparation method and application

Abstract

The present invention belongs to the field of biomedicine, and specifically relates to a ferulic acid derivative based on a protein targeted degradation chimera, and a preparation method and application thereof. The present invention uses 3-aminopiperidine-2,6-dione and 4-fluoroisobenzofuran-1,3-dione as raw materials to prepare compound 1, reacts compound a with three alkane chains (b1-b3) and three PEG chains (b4-b6) in the presence of DIPEA to obtain compound c1-c6, and then reacts in the presence of trifluoroacetic acid to obtain d1-d6, and finally reacts with ferulic acid to obtain a ferulic acid derivative of a protein targeted degradation chimera. The ferulic acid derivative based on targeted protein degradation chimera technology provided by the present invention has higher pharmacological activity than the prototype drug, and effectively improves the pharmacodynamic effect of the prototype drug of the monomer of traditional Chinese medicine; the ferulic acid derivative provided by the present invention has a simple preparation process, easy-to-obtain materials, low cost, and is easy to promote, and has good application prospects in transforming and optimizing the monomer structure of traditional Chinese medicine.

Description

Technical Field

[0001] The invention belongs to the field of biomedicine, and specifically relates to a ferulic acid derivative based on a protein targeted degradation chimera, and a preparation method and application thereof. Background Art

[0002] Phenolic compounds in natural products are compounds with one or more aromatic rings and one or more hydroxyl groups, which are widely distributed in plants. Phenolic acids belong to a large class of phenolic compounds, which are divided into two categories: benzoic acid derivatives and cinnamic acid derivatives. Among them, cinnamic acid derivatives are more common in human daily diet and play an important role in human health. Ferulic acid (FA, 4-hydroxy-3-methoxycinnamic acid) is a phenolic acid derivative of cinnamic acid, which exists in various herbal plants, people's daily staple foods and fruits and vegetables. More and more evidence shows that natural products are of great significance in the treatment of cardiovascular diseases.

[0003] PROTAC (Proteolysis Targeting Chimera) is a ternary complex formed by a ligand that binds to a target protein, an E3 ligase ligand, and an appropriate linker connecting the two compounds. Among them, small molecules can attract target proteins, while the E3 ligands at the other end, such as VHL and CRBN, attract E3 ubiquitin ligases to degrade target proteins, which can improve the oral bioavailability of drugs and promote the transformation of small molecule drugs to clinical applications. Natural products are an important source for PROTAC synthesis and modification.

[0004] Ferulic acid has rich pharmacological activities, but its solubility in hydrophobic media is relatively low, which to some extent limits its ability to pass through lipid-rich cell membranes. Based on this, how to structurally modify and optimize ferulic acid to improve its bioactivity and bioavailability has become an urgent problem to be solved. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a ferulic acid derivative based on a protein targeted degradation chimera. The compound prepared by the present invention can effectively improve the pharmacodynamic effect of the monomer prototype drug of traditional Chinese medicine, and has a good application prospect in the transformation and optimization of the monomer structure of traditional Chinese medicine.

[0006] The present invention further provides a method for preparing the ferulic acid derivative.

[0007] Another object of the present invention is to provide the application of the ferulic acid derivatives.

[0008] In order to achieve the above object, the technical solution of the present invention is as follows:

[0009] The present invention provides a ferulic acid derivative based on a targeted protein degradation chimera, wherein the structural formula of the ferulic acid derivative is:

[0010] Formula I: ;

[0011] or

[0012] Formula II ;

[0013] In formula I, n is 2, 3 or 4; in formula II, n is 1, 2 or 3.

[0014] The present invention also provides a method for preparing the ferulic acid derivative, comprising the following steps:

[0015] (1) Potassium acetate (compound a), 3-aminopiperidine-2,6-dione (compound b) and 4-fluoroisobenzofuran-1,3-dione are added to acetic acid, the mixture is heated to reflux for reaction and stirred, then cooled to room temperature, water is added to the reaction solution to form a precipitate which is collected, filtered and dried to obtain compound c;

[0016] (2) Compound c and compound d are added to DMSO (dimethyl sulfoxide), and then DIPEA (N,N-diisopropylethylamine) is added, and the mixture is heated to reflux for reaction. The coolant is cooled to room temperature, and water is added to terminate the reaction. Ethyl acetate is then added for extraction, and the organic phases are combined, washed, and dried, and evaporated under reduced pressure until dry to obtain compound e;

[0017] (3) Compound e was dissolved in DCM (dichloromethane), and TFA (trifluoroacetic acid) was added dropwise under stirring at room temperature. After the reaction was completed, the mixture was extracted with dichloromethane, and the combined organic phase was washed with water, then dried and concentrated to obtain a crude product. The pH value was adjusted, extracted with DCM, and the organic phase was retained and evaporated under reduced pressure until dryness to obtain compound f;

[0018] (4) EDCI (1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride), HOBT (1-hydroxybenzotriazole) and ferulic acid are dissolved in DCM and stirred at room temperature to obtain a reaction solution. Compound f is added to the reaction solution to react. Water is added to terminate the reaction. The mixture is extracted with DCM / H2O. The organic phase is retained and subjected to rotary drying. The crude product is purified by silica gel column chromatography to obtain the product.

[0019] Furthermore, in step (1), the molar ratio of potassium acetate: 3-aminopiperidine-2,6-dione: 4-fluoroisobenzofuran-1,3-dione is 2.5:1:2; and the heating reflux reaction is carried out at 95° C. for 10 hours.

[0020] Furthermore, in step (2), the molar ratio of compound c:compound d:DIPEA is 1:1.2:2; and the heating reflux reaction is carried out at 95°C for 3 hours.

[0021] Furthermore, in step (2), the structural formula of compound c is: ;

[0022] The structural formula of compound d is: , n is 2, 3 or 4; or , n is 1, 2 or 3.

[0023] Furthermore, in step (3), the molar ratio of compound e to TFA is 2:1; the reaction is carried out at room temperature for 3 hours; and the pH value is adjusted to 7 using a saturated sodium bicarbonate solution.

[0024] Furthermore, in step (3), the structural formula of compound e is: , n is 2, 3 or 4; or , n is 1, 2 or 3;

[0025] The structural formula of compound f is: , n is 2, 3 or 4; or , n is 1, 2 or 3.

[0026] In the above compounds, -Boc is tert-butyloxycarbonyl ( t -Butyloxy carbonyl).

[0027] Furthermore, in step (4), the molar ratio of EDCI: HOBT: ferulic acid: compound f is 1.2:1.2:1:1; and the reaction is carried out at room temperature for 6 hours.

[0028] The present invention also provides the use of the ferulic acid derivative in preparing a medicine for protecting vascular endothelium.

[0029] The reaction process of preparing ferulic acid derivatives of the present invention is as follows:

[0030]

[0031]

[0032] Compared with the Chinese medicine monomer prototype, the beneficial effects of the present invention are as follows:

[0033] (1) The ferulic acid derivatives based on targeted protein degradation chimera technology provided by the present invention have higher pharmacological activity than the prototype drug, effectively improving the pharmacodynamic effect of the monomer prototype drug of traditional Chinese medicine;

[0034] (2) The ferulic acid derivatives provided by the present invention have a simple preparation process, readily available materials, low cost, and are easy to promote. They have good application prospects in the transformation and optimization of the monomer structure of traditional Chinese medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 H-NMR spectrum of ferulic acid derivative (FP-1) based on protein-targeted degradation chimera;

[0036] Figure 2 NMR carbon spectrum of ferulic acid derivative (FP-1) based on protein targeted degradation chimera;

[0037] Figure 3 H-NMR spectrum of the ferulic acid derivative (FP-2) based on the protein-targeted degradation chimera;

[0038] Figure 4 NMR carbon spectrum of ferulic acid derivative (FP-2) based on protein targeted degradation chimera;

[0039] Figure 5 H-NMR spectrum of ferulic acid derivative (FP-3) based on protein-targeted degradation chimera;

[0040] Figure 6 NMR carbon spectrum of ferulic acid derivative (FP-3) based on protein targeted degradation chimera;

[0041] Figure 7 H-NMR spectrum of the ferulic acid derivative (FP-4) based on the protein-targeted degradation chimera;

[0042] Figure 8 NMR carbon spectrum of ferulic acid derivative (FP-4) based on protein targeted degradation chimera;

[0043] Fig. 9 H-NMR spectrum of the ferulic acid derivative (FP-5) based on the protein-targeted degradation chimera;

[0044] Fig.10 NMR carbon spectrum of ferulic acid derivative (FP-5) based on protein targeted degradation chimera;

[0045] Fig.11 H-NMR spectrum of the ferulic acid derivative (FP-6) based on the protein-targeted degradation chimera;

[0046] Fig.12 NMR carbon spectrum of ferulic acid derivative (FP-6) based on protein targeted degradation chimera;

[0047] Fig.13 Ferulic acid derivatives (FP-1~FP-6) based on protein-targeted degradation chimeras affect the survival rate of HUVECs;

[0048] Fig.14Ferulic acid derivatives (FP-1~FP-6) based on protein targeted degradation chimeras improve LPS-induced HUVEC migration function; A is the scratch test at different time (6h, 12h, 24h, 48h); B is the statistical analysis of the scratch test at different time (6h, 12h); C is the statistical analysis of the scratch test at different time (24h, 48h);

[0049] Fig.15 Fluorescence images of ferulic acid derivatives (FP-4) based on protein targeted degradation chimeras protecting zebrafish from vascular endothelial damage; A shows the fluorescence intensity of vascular endothelial fluorescent zebrafish at different doses of FP-4; B shows the statistical analysis of the fluorescence intensity of vascular endothelial fluorescent zebrafish at different doses of FP-4. DETAILED DESCRIPTION

[0050] The embodiments of the present invention will be described in detail below in conjunction with specific examples and accompanying drawings, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0051] The first aspect of the present invention is to provide a ferulic acid derivative based on a protein targeted degradation chimera, the structural formula of which is:

[0052]

[0053] ..

[0054] When the ferulic acid derivatives prepared by the present invention are used to detect the fluorescence intensity of the vascular endothelium of zebrafish damaged by LPS, the specific detection steps are as follows: lipopolysaccharide is used to cause vascular endothelial damage in the zebrafish to be tested, high, medium and low dose groups of ferulic acid and ferulic acid derivatives based on targeted protein degradation chimera technology are respectively intervened in the zebrafish, a blank group and a model group are also set up, the fluorescence intensity of each group is detected on a confocal microscope, and the protective effect of the ferulic acid derivatives based on targeted protein degradation chimera technology on the vascular damage of zebrafish is detected.

[0055] Among them, the lower the fluorescence intensity, the higher the degree of vascular damage to the zebrafish.

[0056] Example 1 Synthesis of Ferulic Acid Derivative (FP-1) Based on Protein Targeted Degradation Chimera

[0057] (1) Potassium acetate (245 mg) and 3-aminopiperidine-2,6-dione (128 mg) were added to a stirred solution of 4-fluoroisobenzofuran-1,3-dione (332 mg) in acetic acid (8 mL), and the mixture was heated to 95°C for reflux and stirred for reaction for 10 h, then cooled to room temperature, 50 mL of water was added to the reaction solution, a precipitate was formed and collected, filtered and dried to obtain a gray solid compound c1, which was directly used in the next step without further purification;

[0058] (2) Compound c (276 mg 1 eq) and tert-butyl N-(4-aminobutyl)carbamate (226 mg) were added to 5 mL DMSO, and then DIPEA (258 mg) was added. The mixture was heated to 95 °C and refluxed for 3 h. After standing at room temperature, water (50 mL) was added to terminate the reaction. Ethyl acetate was then added for extraction (20 mL × 3). The organic phases were combined and washed with saturated sodium chloride solution (20 mL × 3). The organic phases were dried over anhydrous sodium sulfate and evaporated under reduced pressure until dry to obtain a green solid compound e1, which was used directly in the next step without further purification.

[0059] (3) Compound e1 (444 mg) was dissolved in an appropriate amount of DCM (5 mL), and TFA (300 µL) was added dropwise under stirring at room temperature. The reaction was monitored by TLC. After 3 hours of reaction, the mixture was extracted with dichloromethane (20 mL×3). The combined organic phase was washed with water (20 mL×3), dried over anhydrous Na2SO4 and concentrated to obtain a crude product. The pH was adjusted to 7 with saturated sodium bicarbonate solution, extracted with DCM (20 mL×3), and the organic phase was retained and evaporated under reduced pressure until dryness to obtain a yellow-green oily solid compound f1, which was directly used in the next step without further purification.

[0060] (4) EDCI (155 mg), HOBT (126 mg) and ferulic acid (192 mg) were dissolved in DCM (8 mL) and stirred at room temperature. Compound f1 (344 mg) was added to the reaction solution and reacted at room temperature for 6 hours. 50 mL of water was added to terminate the reaction, and the mixture was extracted with DCM / H2O. The organic phase was retained and dried by rotation. The crude product was purified by silica gel column chromatography to obtain a yellow solid FP-1.

[0061] The chemical structure of the ferulic acid derivative (FP-1) based on the protein-targeted degradation chimera is: ;

[0062] The H NMR spectrum of FP-1 is shown in Figure 1 , NMR carbon spectrum see Figure 2 .

[0063] Example 2 Synthesis of Ferulic Acid Derivative (FP-2) Based on Protein Targeted Degradation Chimera

[0064] (1) Potassium acetate (245 mg) and 3-aminopiperidine-2,6-dione (128 mg) were added to a stirred solution of 4-fluoroisobenzofuran-1,3-dione (332 mg) in acetic acid (8 mL), and the mixture was heated to 95°C for reflux and stirred for reaction for 10 h, then cooled to room temperature, 50 mL of water was added to the reaction solution, a precipitate was formed and collected, filtered and dried to obtain a gray solid compound c2, which was used directly in the next step without further purification;

[0065] (2) Compound c2 (276 mg 1 eq) and tert-butyl N-(5-aminopentyl)carbamate (242 mg) were added to 5 mL DMSO, and then DIPEA (258 mg) was added. The mixture was heated to 95 °C and refluxed for 3 h. After standing at room temperature, water (50 mL) was added to terminate the reaction. Ethyl acetate was then added for extraction (20 mL × 3). The organic phases were combined and washed with saturated sodium chloride solution (20 mL × 3). The organic phases were dried over anhydrous sodium sulfate and evaporated under reduced pressure until dry to obtain a green solid compound e2, which was used directly in the next step without further purification.

[0066] (3) Compound e2 (500 mg) was dissolved in an appropriate amount of DCM (5 mL), and TFA (300 µL) was added dropwise under stirring at room temperature. The reaction was monitored by TLC. After 3 hours of reaction, the mixture was extracted with dichloromethane (20 mL×3). The combined organic phase was washed with water (20 mL×3), dried over anhydrous Na2SO4 and concentrated to obtain a crude product. The pH was adjusted to 7 with saturated sodium bicarbonate solution, extracted with DCM (20 mL×3), and the organic phase was retained and evaporated under reduced pressure until dryness to obtain a yellow-green oily solid compound f2, which was directly used in the next step without further purification.

[0067] (4) EDCI (155 mg), HOBT (126 mg) and ferulic acid (192 mg) were dissolved in DCM (8 mL) and stirred at room temperature. Compound f2 (400 mg) was added to the reaction solution and reacted at room temperature for 6 hours. 50 mL of water was added to terminate the reaction, and the mixture was extracted with DCM / H2O. The organic phase was retained and dried by rotation. The crude product was purified by silica gel column chromatography to obtain a yellow solid FP-2.

[0068] The chemical structure of the ferulic acid derivative (FP-2) based on the protein-targeted degradation chimera is: .

[0069] The H NMR spectrum of FP-2 is shown in Figure 3 , NMR carbon spectrum see Figure 4 .

[0070] Example 3 Synthesis of Ferulic Acid Derivative (FP-3) Based on Protein Targeted Degradation Chimera

[0071] (1) Potassium acetate (245 mg) and 3-aminopiperidine-2,6-dione (128 mg) were added to a stirred solution of 4-fluoroisobenzofuran-1,3-dione (332 mg) in acetic acid (8 mL), and the mixture was heated to 95°C for reflux and stirred for reaction for 10 h, then cooled to room temperature, 50 mL of water was added to the reaction solution, a precipitate was formed and collected, filtered and dried to obtain a gray solid compound c3, which was directly used in the next step without further purification;

[0072] (2) Compound c3 (276 mg 1 eq) and tert-butyl N-(6-aminohexyl)carbamate (260 mg) were added to 5 mL DMSO, and then DIPEA (258 mg) was added. The mixture was heated to 95 °C and refluxed for 3 h. After standing at room temperature, water (50 mL) was added to terminate the reaction. Ethyl acetate was then added for extraction (20 mL × 3). The organic phases were combined and washed with saturated sodium chloride solution (20 mL × 3). The organic phases were dried over anhydrous sodium sulfate and evaporated under reduced pressure until dry to obtain a green solid compound e3, which was used directly in the next step without further purification.

[0073] (3) Compound e3 (526 mg) was dissolved in an appropriate amount of DCM (5 mL), and TFA (300 µL) was added dropwise under stirring at room temperature. The reaction was monitored by TLC. After 3 hours of reaction, the mixture was extracted with dichloromethane (20 mL×3). The combined organic phase was washed with water (20 mL×3), dried over anhydrous Na2SO4 and concentrated to obtain a crude product. The pH was adjusted to 7 with saturated sodium bicarbonate solution, extracted with DCM (20 mL×3), and the organic phase was retained and evaporated under reduced pressure until dryness to obtain a yellow-green oily solid compound f3, which was directly used in the next step without further purification.

[0074] (4) EDCI (155 mg), HOBT (126 mg) and ferulic acid (192 mg) were dissolved in DCM (8 mL) and stirred at room temperature. Compound f3 (426 mg) was added to the reaction solution and reacted at room temperature for 6 hours. 50 mL of water was added to terminate the reaction, and the mixture was extracted with DCM / H2O. The organic phase was retained and dried by rotation. The crude product was purified by silica gel column chromatography to obtain a yellow solid FP-3.

[0075] The chemical structure of the ferulic acid derivative (FP-3) of the targeted degradation chimera is:

[0076] ;

[0077] The H NMR spectrum of FP-3 is shown in Figure 5 , NMR carbon spectrum see Figure 6 .

[0078] Example 4 Synthesis of Ferulic Acid Derivative (FP-4) Based on Protein Targeted Degradation Chimera

[0079] (1) Potassium acetate (245 mg) and 3-aminopiperidine-2,6-dione (128 mg) were added to a stirred solution of 4-fluoroisobenzofuran-1,3-dione (332 mg) in acetic acid (8 mL), and the mixture was heated to 95°C for reflux and stirred for reaction for 10 h, then cooled to room temperature, 50 mL of water was added to the reaction solution, a precipitate was formed and collected, filtered and dried to obtain a gray solid compound c4, which was used directly in the next step without further purification;

[0080] (2) Compound c4 (276 mg 1 eq) and amino-diethylene glycol-tert-butyloxycarbonyl (245 mg) were added to 5 mL DMSO, and then DIPEA (258 mg) was added. The mixture was heated to 95 °C and refluxed for 3 h. After standing at room temperature, water (50 mL) was added to terminate the reaction, and then ethyl acetate was added for extraction (20 mL × 3). The organic phases were combined and washed with saturated sodium chloride solution (20 mL × 3). The organic phases were dried over anhydrous sodium sulfate and evaporated under reduced pressure until dry to obtain a green solid compound e4, which was directly used in the next step without further purification.

[0081] (3) Compound e4 (465 mg) was dissolved in an appropriate amount of DCM (5 mL), and TFA (300 µL) was added dropwise under stirring at room temperature. The reaction was monitored by TLC. After 3 hours of reaction, the mixture was extracted with dichloromethane (20 mL×3). The combined organic phase was washed with water (20 mL×3), dried over anhydrous Na2SO4 and concentrated to obtain a crude product. The pH was adjusted to 7 with saturated sodium bicarbonate solution, extracted with DCM (20 mL×3), and the organic phase was retained and evaporated under reduced pressure until dryness to obtain a yellow-green oily solid compound f4, which was directly used in the next step without further purification.

[0082] (4) EDCI (155 mg), HOBT (126 mg) and ferulic acid (192 mg) were dissolved in DCM (8 mL) and stirred at room temperature. Compound f4 (365 mg) was added to the reaction solution and reacted at room temperature for 6 hours. 50 mL of water was added to terminate the reaction, and the mixture was extracted with DCM / H2O. The organic phase was retained and dried by rotation. The crude product was purified by silica gel column chromatography to obtain a yellow solid FP-4.

[0083] The chemical structure of the ferulic acid derivative (FP-4) based on the protein-targeted degradation chimera is:

[0084] ;

[0085] The H NMR spectrum of FP-4 is shown in Figure 7 , NMR carbon spectrum see Figure 8 .

[0086] Example 5 Synthesis of Ferulic Acid Derivative (FP-5) Based on Protein Targeted Degradation Chimera

[0087] (1) Potassium acetate (245 mg) and 3-aminopiperidine-2,6-dione (128 mg) were added to a stirred solution of 4-fluoroisobenzofuran-1,3-dione (332 mg) in acetic acid (8 mL), and the mixture was heated to 95°C for reflux and stirred for reaction for 10 h, then cooled to room temperature, 50 mL of water was added to the reaction solution, a precipitate was formed and collected, filtered and dried to obtain a gray solid compound c5, which was used directly in the next step without further purification;

[0088] (2) Compound c5 (276 mg 1 eq) and amino-diethylene glycol-tert-butyloxycarbonyl (298 mg) were added to 5 mL DMSO, and then DIPEA (258 mg) was added. The mixture was heated to 95 °C and refluxed for 3 h. After standing at room temperature, water (50 mL) was added to terminate the reaction, and then ethyl acetate was added for extraction (20 mL × 3). The organic phases were combined and washed with saturated sodium chloride solution (20 mL × 3). The organic phases were dried over anhydrous sodium sulfate and evaporated under reduced pressure until dry to obtain a green solid compound e5, which was directly used in the next step without further purification.

[0089] (3) Compound e5 (556 mg) was dissolved in an appropriate amount of DCM (5 mL), and TFA (300 µL) was added dropwise under stirring at room temperature. The reaction was monitored by TLC. After 3 hours of reaction, the mixture was extracted with dichloromethane (20 mL×3). The combined organic phase was washed with water (20 mL×3), dried over anhydrous Na2SO4 and concentrated to obtain a crude product. The pH was adjusted to 7 with saturated sodium bicarbonate solution, extracted with DCM (20 mL×3), and the organic phase was retained and evaporated under reduced pressure until dryness to obtain a yellow-green oily solid compound f5, which was directly used in the next step without further purification.

[0090] (4) EDCI (155 mg), HOBT (126 mg) and ferulic acid (192 mg) were dissolved in DCM (8 mL) and stirred at room temperature. Compound f5 (456 mg) was added to the reaction solution and reacted at room temperature for 6 hours. 50 mL of water was added to terminate the reaction, and the mixture was extracted with DCM / H2O. The organic phase was retained and dried by rotation. The crude product was purified by silica gel column chromatography to obtain a yellow solid FP-5.

[0091] The chemical structure of the ferulic acid derivative (FP-5) based on the protein-targeted degradation chimera is:

[0092] ;

[0093] The H NMR spectrum of FP-5 is shown in Fig. 9 , NMR carbon spectrum see Fig.10 .

[0094] Example 6 Synthesis of Ferulic Acid Derivative (FP-6) Based on Protein Targeted Degradation Chimera

[0095] (1) Potassium acetate (245 mg) and 3-aminopiperidine-2,6-dione (128 mg) were added to a stirred solution of 4-fluoroisobenzofuran-1,3-dione (332 mg) in acetic acid (8 mL), and the mixture was heated to 95°C for reflux and stirred for reaction for 10 h, then cooled to room temperature, 50 mL of water was added to the reaction solution, a precipitate was formed and collected, filtered and dried to obtain a gray solid compound c6, which was used directly in the next step without further purification;

[0096] (2) Compound c6 (276 mg 1 eq) and 1,1-dimethylethyl 13-amino-5,8,11-trioxa-2-azatridecanoate (350 mg) were added to 5 mL DMSO, and then DIPEA (258 mg) was added. The mixture was heated to 95°C and refluxed for 3 h. After standing at room temperature, water (50 mL) was added to terminate the reaction. Ethyl acetate was then added for extraction (20 mL × 3). The organic phases were combined and washed with saturated sodium chloride solution (20 mL × 3). The organic phases were dried over anhydrous sodium sulfate and evaporated under reduced pressure until dry to obtain a green solid compound e6, which was used directly in the next step without further purification.

[0097] (3) Compound e6 (608 mg) was dissolved in an appropriate amount of DCM (5 mL), and TFA (300 µL) was added dropwise under stirring at room temperature. The reaction was monitored by TLC. After 3 hours of reaction, the mixture was extracted with dichloromethane (20 mL×3). The combined organic phase was washed with water (20 mL×3), dried over anhydrous Na2SO4 and concentrated to obtain a crude product. The pH was adjusted to 7 with saturated sodium bicarbonate solution, extracted with DCM (20 mL×3), and the organic phase was retained and evaporated under reduced pressure until dryness to obtain a yellow-green oily solid compound f6, which was directly used in the next step without further purification.

[0098] (4) EDCI (155 mg), HOBT (126 mg) and ferulic acid (192 mg) were dissolved in DCM (8 mL) and stirred at room temperature. Compound f6 (508 mg) was added to the reaction solution and reacted at room temperature for 6 hours. 50 mL of water was added to terminate the reaction, and the mixture was extracted with DCM / H2O. The organic phase was retained and dried by rotation. The crude product was purified by silica gel column chromatography to obtain a yellow solid FP-6.

[0099] The chemical structure of the ferulic acid derivative (FP-6) based on the protein-targeted degradation chimera is:

[0100] ;

[0101] The H NMR spectrum of FP-6 is shown in Fig.11 , NMR carbon spectrum see Fig.12 .

[0102] Effect Example 1 Ferulic acid derivatives (FP-1 to FP-6) based on protein targeted degradation chimeras affect the survival rate of HUVEC

[0103] At the same concentration and intervention time, CCK8 was used to test the cell survival activity of FA and ferulic acid derivatives (FP-1~FP-6) prepared in Examples 1-6 on HUVEC. The cells were evenly distributed on a 96-well plate (5000-10000 / well) and incubated overnight. Each tested compound was gradiently diluted into the cells and incubated for 24 hours. After intervention, 100 uL of 10% CCK-8 solution was added to each well and incubated for 2 hours. The absorbance at 450 nm was measured using a full-wavelength microplate reader to calculate cell viability. The half-inhibitory concentration value was calculated and fitted using GraphPad Prism 5.0. 50 )value( Fig.13 ). FP-4~FP-6 IC 50 The values ​​were 31.57, 16.36 and 14.39 µM, respectively, which showed significant antiproliferative activity against HUVEC. Different types and lengths of linkers affect the physicochemical properties and pharmacological activities of ferulic acid derivatives. The ferulic acid derivatives based on protein-targeted degradation chimeras with PEG chains have stronger antiproliferative activity against HUVEC, which may be due to the better cell membrane permeability of the PEG chain structure, which acts through the cells. When comparing different derivatives of the same type of linker, the length of 9 atoms between them may have lower cytotoxicity.

[0104] Effect Example 2 Ferulic acid derivatives (FP-1 to FP-6) based on protein targeted degradation chimeras improve LPS-induced HUVEC migration function

[0105] The cell migration test is a direct test to evaluate the function of vascular endothelial cells. The cell scratch test was performed on HUVEC to test the in vitro efficacy of ferulic acid derivatives (FP-1~FP-6) based on protein targeted degradation chimeras. The performance trend of each compound was basically stable in four time periods ( Fig.14 .A). At 12 hours, there were significant differences between the treatment groups and the model group, with FP-4 performing best ( Fig.14 .B, P<0.001). After 24-48 hours of intervention, FP-5 and FP-6 showed no significant difference compared with the model group, while FP-4 showed no difference compared with the normal group at 24 hours and 48 hours (P>0.05), showing significant pharmacological effects ( Fig.14 .C).

[0106] Effect Example 3 Study on the protection of zebrafish vascular endothelial injury by ferulic acid derivative (FP-4) based on protein targeted degradation chimera

[0107] Transgenic zebrafish (Tg(Fli:EGFP)) 5 days after fertilization were randomly divided into 6 groups, and 20 fish in each group were cultured in six-well plates at 28°C. The model group was modeled with LPS (10µg / mL) for 36 hours, and the drug groups were divided into ferulic acid group (5µmol), FP-4 low-dose group (0.5µmol), FP-4 medium-dose group (1µmol) and FP-4 high-dose group (2µmol). After immersion in LPS for 12 hours, the zebrafish were anesthetized with tetracaine solution (0.016%) for confocal microscopy fluorescence imaging. The fluorescence intensity value of zebrafish endothelial cells was used as the measurement standard to evaluate the intervention effect of ferulic acid and its synthetic derivative FP-4 on lipopolysaccharide-induced endothelial damage. The images were processed and the fluorescence intensity was measured using Image J software, see. Fig.15 , the intensity of green fluorescent protein (GFP) in LPS-induced larvae decreased, indicating that this may indicate a decrease in the number of endothelial cells. Each group received 24 hours of drug intervention 12 hours after LPS modeling, and then fluorescence imaging was performed. There was a significant difference between the FA group (10 µM) and the model group (P<0.01), which had a certain repair effect on zebrafish endothelial injury. Among the FP-4 groups with different concentrations, there was almost no difference between the low-dose group (0.5µmol) and the model group. The medium-dose group (1µM) and the high-dose group (2µM) significantly increased the fluorescence intensity of endothelial cells, which was significantly different from the model group, proving that FP-4 can effectively improve LPS-induced endothelial cell damage.

Claims

1. A ferulic acid derivative based on a targeted protein degradation chimera, characterized in that: The structural formula of the ferulic acid derivative is: Formula I: or Formula II ; In formula I, n is 2, 3 or 4; in formula II, n is 1, 2 or 3.

2. A method for preparing a ferulic acid derivative based on a targeted protein degradation chimera as claimed in claim 1, characterized in that: The following steps are involved: (1) adding potassium acetate, 3-aminopiperidine-2,6-dione and 4-fluoroisobenzofuran-1,3-dione to acetic acid, heating the mixture to reflux for reaction and stirring, then cooling to room temperature, adding water to the reaction solution to form a precipitate which is collected, filtered and dried to obtain compound c; (2) Compound c and compound d are added to DMSO, and then DIPEA is added, and the mixture is heated under reflux for reaction. The coolant is cooled to room temperature, water is added to terminate the reaction, and then ethyl acetate is added for extraction. The organic phases are combined, washed, and dried, and evaporated under reduced pressure until dry to obtain compound e; (3) Compound e was dissolved in DCM, TFA was added dropwise under stirring at room temperature, and after the reaction was completed, the mixture was extracted with dichloromethane, the combined organic phase was washed with water, and then dried and concentrated to obtain a crude product, the pH value was adjusted, extracted with DCM, the organic phase was retained, and evaporated under reduced pressure until dryness to obtain compound f; (4) dissolving EDCI, HOBT and ferulic acid in DCM and stirring at room temperature to obtain a reaction solution, adding compound f to the reaction solution for reaction, adding water to terminate the reaction, extracting with DCM / H2O, retaining the organic phase for rotary drying, and purifying the crude product by silica gel column chromatography to obtain the product; The structural formula of compound c is: ; The structural formula of compound d is: , n is 2, 3 or 4; or , n is 1, 2 or 3; The structural formula of compound e is: , n is 2, 3 or 4; or , n is 1, 2 or 3; The structural formula of compound f is: , n is 2, 3 or 4; or , n is 1, 2 or 3.

3. The preparation method according to claim 2, characterized in that: In step (1), the molar ratio of potassium acetate: 3-aminopiperidine-2,6-dione: 4-fluoroisobenzofuran-1,3-dione is 2.5:1:2; the heating reflux reaction is carried out at 95° C. for 10 hours.

4. The preparation method according to claim 2, characterized in that: In step (2), the molar ratio of compound c: compound d: DIPEA is 1:1.2:2; the heating reflux reaction is carried out at 95° C. for 3 hours.

5. The preparation method according to claim 2, characterized in that: In step (3), the molar ratio of compound e to TFA is 2:1; the reaction is carried out at room temperature for 3 hours; and the pH value is adjusted to 7 using a saturated sodium bicarbonate solution.

6. The preparation method according to claim 2, characterized in that: In step (4), the molar ratio of EDCI: HOBT: ferulic acid: compound f is 1.2:1.2:1:1; the reaction is carried out at room temperature for 6 hours.

7. Use of the ferulic acid derivative according to claim 1 in the preparation of a drug for protecting vascular endothelium.

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