CN114246851B - Synthesis method and use of a small molecule inhibitor of histone methyltransferase SMYD3 - Google Patents

Abstract

The invention relates to a histone methyltransferase SMYD3 small molecule inhibitor, which belongs to the field of western medicine pharmacy, and mainly relates to the structure, synthesis and application of the histone methyltransferase SMYD3 small molecule inhibitor in treating cancers such as liver cancer and the like. According to the invention, a novel SMYD3 small molecule inhibitor is screened, simulated and synthesized by a computer, and the results of in-vitro and in-vitro experimental model researches show that the histone methyltransferase SMYD3 small molecule inhibitor can be combined with SMYD3 protein in an energy dose-dependent manner in vitro, so that the activity of the SMYD3 enzyme is reduced, and the histone methyltransferase SMYD3 small molecule inhibitor has good drug properties by computer analysis. Can reduce proliferation of various cancer cells at the cellular level in a dose-dependent manner, and has no obvious toxicity to mice. Can inhibit the growth of in-situ liver HepG2 tumor of NTG mice, can reduce the expression level of liver SMYD3 protein of mice with in-situ liver tumor in the mice, and proves that the histone methyltransferase SMYD3 small molecule inhibitor has remarkable therapeutic effect on liver cancer, and is safe and effective.

Description

Synthesis method and method of a small molecule inhibitor of histone methyltransferase SMYD3 use

Technical field

The present invention relates to the technical field of western medicine pharmaceuticals, and specifically to a small molecule inhibitor of histone methyltransferase SMYD3 and its synthesis method and use.

Background technique

SMYD3 (SET and MYND domain protein 3) is a protein with histone methylation function discovered in recent years. It can cause dimethylation or trimethylation of chromosomal histones (H3K4, etc.), leading to changes in the spatial structure of chromosomes, changing the tightness and openness of the transcription complex, regulating gene transcription, thereby affecting downstream oncogenes and cell cycle genes. , nuclear hormone receptors, adhesion-related genes, inhibit tumor cell apoptosis, and promote cell proliferation, invasion and metastasis. Multiple studies have confirmed that SMYD3 is highly expressed in different types of cancer cells, while the expression level in corresponding normal tissues is low or even undetectable. SMYD3 gene silencing experiments observed significant tumor cell growth inhibition and increased apoptosis. Therefore, SMYD3 has become a new epigenetic target for anti-tumor drugs. The vast majority of SMYD3 inhibitors reported in the literature are polypeptides, and there is still a lack of research on small molecule inhibitors. Compared with biological macromolecules, small molecule inhibitors have the advantages of being relatively easy to synthesize due to their simple structure, can be taken orally, are easy to store and transport, have good tissue permeability, can partially pass through the blood-brain barrier, and have no immunogenicity; it has been reported Although several small molecule inhibitors can inhibit the expression of SMYD3 to a certain extent, they have problems such as poor biocompatibility and low inhibition efficiency. There are no reports on efficient, safe and selective small molecule targeted anti-cancer drugs targeting the SMYD3 target.

Contents of the invention

In view of this, it is necessary to provide a small molecule inhibitor of histone methyltransferase SMYD3.

It is also necessary to provide a synthesis method of a small molecule inhibitor of histone methyltransferase SMYD3.

There is also a need to provide a small molecule inhibitor of histone methyltransferase SMYD3.

A small molecule inhibitor of histone methyltransferase SMYD3. The molecular formula of the small molecule inhibitor of histone methyltransferase SMYD3 is: C ₂₅ H ₂₄ N ₂ O ₂ .

Preferably, the chemical structural formula of the histone methyltransferase SMYD3 small molecule inhibitor is:

A method for synthesizing a small molecule inhibitor of histone methyltransferase SMYD3, including the following steps:

Weigh the corresponding compound 1,3-indandione into a flask, add anhydrous acetonitrile, stir to dissolve, then add methyl iodide and potassium fluoride, fill the reaction system with nitrogen, react at 70 degrees Celsius, and then Check the progress of the reaction. After the reaction is completed, cool to room temperature, then add H ₂ O to the reaction solution for quenching, extract with CH ₂ Cl ₂ , collect the organic phase, dry over anhydrous Na ₂ SO ₄ , and concentrate under reduced pressure. The intermediate 2,2-dimethylindandione is obtained through column chromatography separation;

Weigh the above intermediate 2,2-dimethylindandione and place it in a flask. Add anhydrous toluene and stir to dissolve. Then add p-anisidine and potassium fluoride and slowly drip in under stirring conditions. Add 1-2 drops of p-toluenesulfonic acid, react under reflux conditions, and then check the reaction progress. After the reaction is completed, cool to room temperature, add H ₂ O to the reaction solution to quench, extract with CH ₂ Cl ₂ , and collect The organic phase was dried over anhydrous Na ₂ SO ₄ , concentrated under reduced pressure, and separated by column chromatography to obtain a small molecule inhibitor of histone methyltransferase SMYD3, which was defined as ZYZ384.

Preferably, in the synthesis method of the histone methyltransferase SMYD3 small molecule inhibitor, use an electronic analytical balance to weigh 2 mmol of the corresponding compound 292.2 mg of 1,3-indandione, place it in a 25 mL round-bottomed flask, and add 2 mL Anhydrous acetonitrile, stir to dissolve, then add 6 mmol methyl iodide and 10 mmol potassium fluoride, and use thin layer chromatography to detect the reaction progress. After the reaction is completed, cool to room temperature, add H ₂ O to the reaction solution to quench, and use 3×20mL CH ₂ Cl ₂ extraction;

Use an electronic analytical balance to weigh 1 mmol of the above intermediate 2,2-dimethylindandione (174.1 mg), place it in a 25 mL round bottom flask, add 2 mL of anhydrous toluene, stir to dissolve, and then add 2.5 mmol of p-fennel Take 308 mg of amine and 10 mmol of potassium fluoride, slowly add 1-2 drops of p-toluenesulfonic acid under stirring conditions, react under reflux conditions, and use thin layer chromatography and TLC to detect the reaction progress. After the reaction is completed, cool to room temperature. , add H ₂ O to the reaction solution for quenching, and extract with 3 × 20 mL CH ₂ Cl ₂ .

A small molecule inhibitor of histone methyltransferase SMYD3 is used to reduce the proliferation of cancer cells.

Preferably, the small molecule inhibitor of histone methyltransferase SMYD3 is used as a therapeutic drug for liver cancer.

Preferably, a small molecule inhibitor of histone methyltransferase SMYD3 is used to inhibit the growth of liver in situ tumors.

Preferably, the small molecule inhibitor of histone methyltransferase SMYD3 is used to reduce the proliferation of lung cancer cells, human colon cancer cells, human breast cancer cells or human pancreatic adenocarcinoma cells.

The present invention performs virtual screening through Schrödinger software, tests 100,000 candidate small molecules to identify SMYD3 inhibitors, and selects the top-ranked molecules to evaluate their binding activity through BLI (Bio-layer interferometry, biological film layer interference technology) experiments. Lead compound. The structure of the lead compound was modified and a series of new small molecule inhibitors were synthesized. Their inhibitory activities were measured using BLI and SMYD3 enzyme activity experiments. Among them, the small molecule inhibitor of histone methyltransferase SMYD3 showed the best binding ability. and inhibitory potency. After computer analysis of the druggability of histone methyltransferase SMYD3 small molecule inhibitors, the anticancer activity of histone methyltransferase SMYD3 small molecule inhibitors against different cancer cell lines in vitro was further tested. After using C57 mice to evaluate the safety of small molecule inhibitors of histone methyltransferase SMYD3, an orthotopic HepG2 orthotopic tumor model was established in NTG mice. After three weeks of intragastric administration, materials were collected. The livers and spleens of each group were collected and observed. Statistical Analysis.

The results show that small molecule inhibitors of histone methyltransferase SMYD3 bind to SMYD3 protein in a dose-dependent manner and reduce SMYD3 enzyme activity. Small molecule inhibitors of histone methyltransferase SMYD3 significantly reduced the proliferation of different cancer cells in a dose-dependent manner: including human liver cancer cell HepG2, human non-small cell lung cancer cell A549, human colon cancer cell HTC116, and human breast cancer cell MDA- MB-231 and human pancreatic adenocarcinoma cell Miapaca2. Among them, small molecule inhibitors of histone methyltransferase SMYD3 showed significant inhibitory effects on HepG2 proliferation and had anti-cancer cell proliferation effects. The maximum dose of a small molecule inhibitor of histone methyltransferase SMYD3 was administered to C57 mice at one time and then observed for fourteen days. No mouse died within fourteen days. Small molecule inhibitors of histone methyltransferase SMYD3 can inhibit the growth of HepG2 orthotopic implanted tumors in the liver of NTG (severe combined immunodeficiency) mice, and can reduce the expression of SMYD3 protein in the liver of orthotopic tumor models in vivo. In this way, the small molecule inhibitor of histone methyltransferase SMYD3 provided by the present invention has a significant therapeutic effect on liver cancer, is safe and effective, and can be used to prepare drugs for the treatment of liver cancer and other cancers.

Description of the drawings

Figure 1 is a schematic diagram of the chemical structural formula of a small molecule inhibitor of histone methyltransferase SMYD3;

Figure 2 is a schematic diagram of the synthesis route of small molecule inhibitors of histone methyltransferase SMYD3;

Figure 3 is a schematic diagram of the binding and dissociation curves of ZYZ384 and SMYD3 protein at different concentrations using BLI experiments;

In the figure: Curve a is the binding and dissociation curve of 200 μM, curve b is the binding and dissociation curve of 100 μM, curve c is the binding and dissociation curve of 50 μM, curve d is the binding and dissociation curve of 25 μM, and curve e is the binding of 12.25 μM. Dissociation curve, curve f is the binding and dissociation curve of 6.25μM;

Figure 4 is a schematic diagram of the fitting curve using BLI experiment to detect ZYZ384 and SMYD3 proteins;

In the figure: KD: equilibrium dissociation constant, Kon: binding constant, Kdis: dissociation constant, R2: linear regression coefficient of determination;

Figure 5 is a schematic diagram of the interaction site between ZYZ384 and SMYD3 protein based on molecular docking simulation;

Figure 6 is a schematic diagram of the analysis results of ZYZ384 inhibiting SMYD3 enzyme activity in vitro;

Figure 7 is a schematic diagram of the druggability research analysis curve of the SMYD3 small molecule inhibitor ZYZ384 and its related inhibitors;

Figure 8 is a schematic diagram of using the MTT method to detect the inhibitory effect of ZYZ384 on the proliferation of different cancer cells;

In the picture: HepG2: human liver cancer cell, Miapaca2: human pancreatic adenocarcinoma cell, MDA-MB-231 human breast cancer cell, HTC116 human colon cancer cell, A549: human non-small cell lung cancer cell. **: p<0.01; ***: p<0.001;

Figure 9 is a schematic diagram of the results of evaluating the safety of ZYZ384 using the mouse acute toxicity test method;

Figure 10 is a schematic diagram of the results of testing the anti-tumor effect of ZYZ384 using the NTG mouse orthotopic tumor model;

Among them: Control: normal control group, Model: model group, ZYZ384: model+ZYZ384. ###:p<0.001vsControl; ***:p<0.001vs Model; **:p<0.01vs Model

Figure 11 is a schematic diagram of the results of detecting SMYD3 protein levels in mouse liver tissue using immunohistochemistry and Westernblot methods;

In the figure, the data is compared with the target gene and the corresponding internal reference GAPDH; where: control: normal control group, Model: model group, ZYZ384: model + ZYZ384, *: p<0.05vs Control; #: p<0.05vs Model.

Detailed ways

In order to make the technical solution of the present invention easier to understand, the technical solution of the present invention is now clearly and completely described by way of specific embodiments in conjunction with the accompanying drawings.

Example 1, please refer to Figure 1 and Figure 2 at the same time. The specific synthesis route of the histone methyltransferase SMYD3 small molecule inhibitor is:

Use an electronic analytical balance to weigh the corresponding compound 1,3-Indanedione (292.2 mg, 2 mmol) into a 25 mL round-bottomed flask, add 2 mL anhydrous acetonitrile, stir to dissolve, and then add Methyl iodide (6mmol)) and potassium fluoride (10mmol), fill the reaction system with nitrogen, react at 70 degrees, use thin layer chromatography (TLC) to detect the reaction progress, after the reaction is completed, cool to room temperature, the reaction solution Add H ₂ O to quench, extract with CH ₂ Cl ₂ (3 × 20 mL), collect the organic phase, dry over anhydrous Na ₂ SO ₄ , concentrate under reduced pressure, and separate by column chromatography to obtain the intermediate 2,2-bis Methylindanedione (2,2-Dimethylindan-1,3-dione) 313 mg, yield 90%. Nuclear magnetic resonance spectrum: ¹ H NMR (600MHz DMSO) δ7.99-8.03 (m, 4H), 1.18 (s, 6H); ¹³ C NMR (150MHz, DMSO) δ 203.24, 139.23, 135.92, 122.84, 48.63, 19.47.

Use an electronic analytical balance to weigh the above intermediate 2,2-dimethylindandione (174.1 mg, 1 mmol) into a 25 mL round-bottomed flask, add 2 mL anhydrous toluene, stir to dissolve, and then add p-fennel Amine (308 mg, 2.5 mmol)), potassium fluoride (10 mmol), slowly drop 1-2 drops of p-toluenesulfonic acid under stirring conditions, react under reflux conditions, and use thin layer chromatography (TLC) to detect the reaction. After the reaction is completed, cool to room temperature, add H ₂ O to the reaction solution to quench, extract with CH ₂ Cl ₂ (3×20 mL), collect the organic phase, dry over anhydrous Na ₂ SO ₄ , and concentrate under reduced pressure , column chromatography separated and obtained 238 mg of histone methyltransferase SMYD3 small molecule inhibitor with a yield of 62%. Nuclear magnetic resonance spectrum: ¹ H NMR (600MHz, DMSO) δ8.08 (dd, J＝1.6, 7.6Hz, 2H), 7.74 (dd, J＝1.6, 7.6Hz, 2H), 7.38 (d, J＝7.6Hz ,4H,6.96(d,J＝7.6Hz,4H),3.79(s,6H),1.03(s,6H); ¹³ C NMR(150MHz,DMSO)δ165.4,158.2,144.5,132.8,131.4,131.0,122.9 ,114.9,56.0,44.1,26.2.

The molecular formula of the small molecule inhibitor of histone methyltransferase SMYD3 is: C ₂₅ H ₂₄ N ₂ O ₂ .

The chemical structural formula of the small molecule inhibitor of histone methyltransferase SMYD3 is shown in Figure 1, and the synthetic route is shown in Figure 2. The naming method of the small molecule inhibitor of histone methyltransferase SMYD3 adopts the name of the research and development project group of this application. Abbreviation ZYZ and molecular weight designation, named ZYZ384.

Example 2 Experiment on the binding ability of ZYZ384 and SMYD3 protein

Methods: SMYD3-GST tagged protein was immobilized on glutathione S-transferase (GST) biosensor (Fortebio). ZYZ384 was diluted into different concentrations, ranging from 6.25 μM to 200 μM. After setting the baseline with PBS, the biosensor tip was immersed in wells containing serial dilutions of ZYZ384 for 180 seconds of association and 180 seconds of dissociation. Save the data, use the 1:1 binding model in data analysis software 9.0 (Fortebio) to calculate the KD value, and monitor the binding and dissociation curves in real-time mode. Please also refer to Figure 3. Curve a is the binding and dissociation curve of 200 μM, and curve b is The binding and dissociation curve of 100 μM, curve c is the binding and dissociation curve of 50 μM, curve d is the binding and dissociation curve of 25 μM, curve e is the binding and dissociation curve of 12.25 μM, and curve f is the binding and dissociation curve of 6.25 μM; computer According to the binding and dissociation curve analysis in Figure 3, the results shown in Figure 4 are calculated, showing that the linear regression determination coefficient R ² =0.9563, according to the simple 1:1 binding mode, the equilibrium dissociation constant of the interaction between SMYD3 and ZYZ384 (KD) is 79.9 μM, and the binding and dissociation of ZYZ384 and SMYD3 are dose-dependent.

Example 3 Molecular docking of ZYZ-384 and SMYD3 protein

ZYZ-384 and SMYD3 protein were analyzed by molecular docking using CDOCKER of Discovery Studio (2021) software. The optimal binding mode and interaction were analyzed by Discovery Studio software and Pymol (Version 2.5.2) software. The binding energy of ZYZ-384 and SMYD3 is -8.73kcal/mol, and the binding pocket is reasonable, which is conducive to maintaining the stable conformation of ZYZ-384 and SMYD3. As shown in Figure 5, the binding region includes SER-182, PHE-183, and CYS-186. , MET-190, ILE-214, TYR-257, LYS-297, HIS-366 and VAL-368 and other amino acid residues, can form various interactions such as hydrogen bonds, van der Waals forces and Pi-Pi conjugation, Among them, the methoxy group on ZYZ-384 forms hydrogen bond interactions with TYR-257, SER-182, ASP-332 and LYS-297 of Smyd3 protein, and PHE-183, ILE-214, HIS-366, VAL- of SMYD3 368 and MET-190 have conjugated interactions with ZYZ-384. These interactions are important for maintaining the stability of the complex between ZYZ-384 and SMYD3. These action sites may be key sites for the physiological effects of ZYZ-384.

Example 4 ZYZ384 inhibition of SMYD3 enzyme activity experiment

Methods: Using the SMYD3 homogeneous detection kit (BPS bioscience, USA), methyltransferase activity can be detected in just three simple steps on a microtiter plate. First, samples containing the SMYD3 enzyme were incubated with substrate and varying concentrations of inhibitor (ZYZ384) for three hours. Next, acceptor beads and primary antibodies are added, and finally donor beads are added, and the alpha count is read.

The experimental results show in Figure 6 that ZYZ384 can reduce SMYD3 enzyme activity in a dose-dependent manner.

Example 5 ADMET prediction of Smyd3 inhibitor ZYZ-384 and its related inhibitors

Method: Use Discovery Studio software to calculate ADMET (drug absorption

, Distribution, Metabolism, Excretion and Toxicity) Properties: aqueous solubility at 25 degrees Celsius; blood brain barrier permeability (BBB); Cytochrome P4502D6 inhibition (Cytochrome P4502D6inhibition), hepatotoxicity (hepatotoxicity); human intestinal absorption (HIA), plasma protein binding rate (plasma protein binding), through Small Molecules|CalculateMolecular Properties|ADMET Descriptors in Discovery Studio, parameter selection default settings, ZYZ-384 will be calculated The ADMET properties of its related inhibitors, the results are shown in Figure 3 and Figure 4. The ADMET plot is a two-dimensional graph of ADMET_PSA_2D vsADMET_AlogP98. The two-dimensional graph respectively represents the blood-brain barrier permeability (BBB) model95 % and 99% confidence intervals, as well as the 95% and 99% confidence intervals of the Human Intestinal Absorption (HIA) model. As shown in Figure 7, ZYZ-384 has good ADMET properties and good drugability.

Example 6 ZYZ384 cytotoxicity experiment.

Method: Cells (1×104/well) in 100 mL culture medium were seeded in a 96-well plate and treated with ZYZ384. After 24 hours of treatment, cell viability was determined by adding 1 mg/ml MTT-containing medium for 4 hours and then adding 100 ml DMSO to dissolve formazan. A microplate UV/VIS spectrophotometer (Tecan, Mannedorf, Switzerland) was used to record the absorbance at 570 nm and cell proliferation. The results are shown in Figure 8, which shows that ZYZ384 significantly reduces the proliferation of different cancer cells in a dose-dependent manner: including Human liver cancer cell HepG2, adenocarcinoma human alveolar basal epithelial cell A549, human colon cancer cell HTC116, human breast cancer cell MDA-MB-231 and human pancreatic adenocarcinoma cell Miapaca2. Among them, ZYZ384 showed a significant inhibitory effect on HepG2 proliferation ( IC50=5.23μM).

Experimental results prove that the ZYZ384 has significant inhibitory effects on the proliferation of various cancer cells.

Example 7 ZYZ384 animal toxicity test

Grouping of C57 mice: 20 C57 male mice in good condition, 6 weeks old and weighing 22-26g, weighing 18-22g were randomly selected and randomly divided into a blank group and a drug administration group (n=10). The maximum dose of 2g/kg/time was given via intragastric administration once, and the patient was observed continuously for 14 days. As shown in Figure 9, the experimental results showed that no case died within 14 days after administration, and no abnormalities were found in the mice's food intake, water intake, and spontaneous activities. The LD50 of ZYZ384>2g/kg.

Example 8 Experiment on ZYZ384 inhibiting the growth of liver orthotopic tumors in NTG mice

Grouping of NTG mice: Randomly select 30 male NTG mice that are 6 weeks old and weigh 22-26g and are in good condition, and randomly divided into 3 groups (n=10), namely: ①CON is the normal control group; ②MODEL is the model group; ③ZYZ384 Add ZYZ384 group to the model group; mice in groups ② and ③ were anesthetized by intraperitoneal injection of 0.8% sodium pentobarbital (75 mg/kg), fixed in a supine position, shaved abdominal hair, and cut the skin upward along the midline of the abdomen 2cm below the sternum. About 1cm, separate and cut the peritoneum, expose the liver, press the abdomen gently, squeeze out the left lobe of the liver, and use a syringe to slowly inject 100μL of HepG2 cell suspension (1×106/100μL) into the liver parenchyma under the liver capsule. The needle is in contact with the liver. The surface is at an angle of about 30° and the penetration depth is 1cm. If the liver tissue at the injection site turns white, it proves that the injection is successful. Slowly remove the needle and gently press the injection site with hemostatic cotton to prevent bleeding and cell overflow. The liver was returned to its natural position, and the peritoneal and skin incisions were sutured with No. 6.0 absorbable surgical sutures. At 3 weeks after inoculation, the appearance of small gray-white nodules at the inoculation site on the surface of the liver indicated the success of the model. Administration: Group ③ was given ZYZ384 100 mg/kg/day by intragastric administration every day. After 3 weeks, the mice were sacrificed, and the livers and spleens were isolated for subsequent analysis and detection. The experimental data were subjected to one-way analysis of variance, p<0.05.

Please refer to Figure 10 and Figure 11 at the same time: After harvesting liver materials from NTG mice, it can be observed that the liver morphology of the blank group is normal, the liver of the model group is severely adhesions, shrunken, irregular in shape, and diffuse masses are prominent; the morphology of the drug group is relatively normal , less lumps. The weight of liver and spleen in the model group increased compared with the blank group, and the weight decreased after treatment. The statistical results are shown in Figure 10. HE staining results showed that the liver cells in the blank group had complete morphology, and the blue staining inside the cells was the nucleus. The nucleus was large, round, and centered, and the cytoplasm was rich and mostly eosinophilic. The hepatocyte morphology in the model group was missing, the nucleus was obviously atypia, and the cytoplasm was deeply stained and obviously basophilic. In the administration group, normal cells and atypical cells coexisted. The cell nuclei were of different sizes, the cytoplasm was slightly darkly stained, and the cell morphology was often different. The immunohistochemistry and western blot results of liver tissue showed that SMYD3 was highly expressed in the model group, while the expression level was low in the blank and drug treatment groups. The statistical results are shown in Figure 11. It is proved that ZYZ384 can significantly inhibit the growth of liver tumor in situ.

It should be noted that the embodiments described here are only some of the embodiments of the present invention, rather than all implementations of the present invention. The embodiments are only illustrative, and their function is only to provide a more intuitive and clear understanding of the content of the present invention. way, rather than limiting the technical solutions described in the present invention. Without departing from the concept of the present invention, all other implementations that those skilled in the art can think of without creative work, as well as other simple replacements and various changes of the technical solutions of the present invention, all belong to the protection of the present invention.

Claims (6)

1. A small molecule inhibitor of histone methyltransferase SMYD3, characterized in that: the molecular formula of the small molecule inhibitor of histone methyltransferase SMYD3 is: C ₂₅ H ₂₄ N ₂ O ₂ ; The chemical structural formula of the small molecule inhibitor of histone methyltransferase SMYD3 is: 2. The synthetic method of histone methyltransferase SMYD3 small molecule inhibitor as claimed in claim 1, characterized in that: the synthetic method of histone methyltransferase SMYD3 small molecule inhibitor includes the following steps: Weigh the corresponding compound 1,3-indandione into a flask, add anhydrous acetonitrile, stir to dissolve, then add methyl iodide and potassium fluoride, fill the reaction system with nitrogen, react at 70 degrees Celsius, and then Check the progress of the reaction. After the reaction is completed, cool to room temperature, then add H ₂ O to the reaction solution for quenching, extract with CH ₂ Cl ₂ , collect the organic phase, dry over anhydrous Na ₂ SO ₄ , and concentrate under reduced pressure. The intermediate 2,2-dimethylindandione is obtained through column chromatography separation; Weigh the above intermediate 2,2-dimethylindandione and place it in a flask. Add anhydrous toluene and stir to dissolve. Then add p-anisidine and potassium fluoride and slowly drip in under stirring conditions. Add 1-2 drops of p-toluenesulfonic acid, react under reflux conditions, and then check the reaction progress. After the reaction is completed, cool to room temperature, add H ₂ O to the reaction solution to quench, extract with CH ₂ Cl ₂ , and collect The organic phase was dried over anhydrous Na ₂ SO ₄ , concentrated under reduced pressure, and separated by column chromatography to obtain a small molecule inhibitor of histone methyltransferase SMYD3. 3. The synthetic method of histone methyltransferase SMYD3 small molecule inhibitor as claimed in claim 2, characterized in that: in the synthetic method of histone methyltransferase SMYD3 small molecule inhibitor, an electronic analytical balance is used to weigh the corresponding 292.2 mg of the compound 2 mmol of 1,3-indandione was placed in a 25 mL round-bottomed flask, and 2 mL of anhydrous acetonitrile was added, stirred to dissolve, then 6 mmol of methyl iodide and 10 mmol of potassium fluoride were added, and thin layer chromatography was performed. Check the reaction progress. After the reaction is completed, cool to room temperature, add H ₂ O to the reaction solution to quench, and extract with 3 × 20 mL CH ₂ Cl ₂ ; Use an electronic analytical balance to weigh 1 mmol of the above intermediate 2,2-dimethylindandione (174.1 mg), place it in a 25 mL round bottom flask, add 2 mL of anhydrous toluene, stir to dissolve, and then add 2.5 mmol of p-fennel Take 308 mg of amine and 10 mmol of potassium fluoride, slowly add 1-2 drops of p-toluenesulfonic acid under stirring conditions, react under reflux conditions, and use thin layer chromatography and TLC to detect the reaction progress. After the reaction is completed, cool to room temperature. , add H ₂ O to the reaction solution for quenching, and extract with 3 × 20 mL CH ₂ Cl ₂ . 4. Use of the small molecule inhibitor of histone methyltransferase SMYD3 as claimed in claim 1, characterized in that: the small molecule inhibitor of histone methyltransferase SMYD3 is used to prepare therapeutic drugs for liver cancer. 5. The use of the histone methyltransferase SMYD3 small molecule inhibitor as claimed in claim 1, characterized in that: the histone methyltransferase SMYD3 small molecule inhibitor is used to prepare and reduce lung cancer cells, human colon cancer cells, Proliferation drugs for human breast cancer cells or human pancreatic adenocarcinoma cells. 6. The use of the histone methyltransferase SMYD3 small molecule inhibitor as claimed in claim 1, characterized in that: the histone methyltransferase SMYD3 small molecule inhibitor is used to prepare drugs that inhibit the growth of liver in situ tumors.