3-substituted dihydrocarveatic acid difluoromethyl ester compounds, methods of making and uses thereof

Abstract

This invention discloses a 3-substituted ursolic acid difluoromethyl ester compound, its preparation method, and its uses, belonging to the field of chemical pharmaceutical raw materials and formulation manufacturing. The compound is prepared by etherification of the 3-hydroxyl group of ursolic acid and modification of the 28-carboxyl group to a difluoromethyl ester group. In the general formula, R is selected from hydrogen, C1-C9 alkyl, C2-C6 alkynyl, C2-C6 alkenyl, C3-C8 cycloalkyl, or aralkyl. The preparation employs a two-step method: ursolic acid reacts with HCF₂Cl under alkaline catalysis to generate intermediate B, which is then alkylated to obtain the target compound. The compound of this invention exhibits strong inhibitory activity against five types of tumor cells, including gastric cancer and lung cancer, with an IC₂ concentration of [missing value]. 50 It is danamol grade and has significant antibacterial and hypoglycemic effects. It has low acute toxicity, high safety, mild preparation process, and is suitable for industrial production. It can be used to prepare antitumor, antibacterial, and hypoglycemic drugs.

Description

Technical Field

[0001] This invention relates to the fields of carbocyclic compounds and organic chemistry, specifically to 3-substituted ursolic acid difluoromethyl ester compounds, their preparation methods, and their uses. Background Technology

[0002] Ursolic acid is a triterpenoid compound widely found in natural plants. It has rich pharmacological activities and possesses a variety of pharmacological effects, including antibacterial, antidiabetic, antiulcer, antitumor, antiviral, and hepatoprotective properties. It has outstanding safety and application value and is currently widely used as a pharmaceutical intermediate and a core raw material for cosmetics, with broad prospects for industrial application.

[0003] However, ursolic acid has significant shortcomings in its physicochemical properties and drug safety, which greatly limits its clinical and industrial applications. On the one hand, ursolic acid has extremely poor water solubility, resulting in very low oral absorption and utilization rates and poor bioavailability. Combined with factors such as intestinal flora metabolism and the first-pass effect of the liver, its retention time is insufficient, making it difficult to fully exert its pharmacological effects. On the other hand, ursolic acid is prone to causing gastrointestinal adverse reactions such as nausea, vomiting, diarrhea, and abdominal pain during actual administration and use, which reduces medication compliance and restricts its dosage increase and long-term use.

[0004] To address the aforementioned deficiencies, researchers have conducted extensive work on the structural modification of ursolic acid. Existing research mainly focuses on structural modification, including the synthesis and antitumor activity studies of ursolic acid-triazole derivatives (Kuai Zhenyu, et al. Acta Pharmaceutica Sinica. 2025, 60: 172-178), and structurally modified ursolic acid compounds and their antitumor activities (Bai Yujun, et al. West China Journal of Pharmaceutical Sciences. 2003, 18: 87-90). Several related patents have also been disclosed, including CN202410768059.9, CN201880059850.5, CN201710025716.0, and CN201510194921.0.

[0005] However, research has verified that the ursolic acid structural modification techniques disclosed in the aforementioned literature mainly focus on improving some anti-tumor related properties. They fail to fundamentally and effectively solve the core problems of poor water solubility, poor in vivo absorption, and low bioavailability of ursolic acid, nor can they effectively reduce the incidence of gastrointestinal adverse reactions. These techniques still suffer from limitations in modification effects and overall performance improvement, making it difficult to meet the actual industrialization needs of the pharmaceutical and cosmetic fields for high-performance modified ursolic acid products. Therefore, developing an ursolic acid modification technology that can simultaneously improve ursolic acid water solubility, enhance in vivo pharmacokinetic performance, and reduce toxic side effects and adverse reactions has significant research value and market potential. Summary of the Invention

[0006] To address the technical problems of existing ursolic acid structural modifications, such as limited modification effects, inability to simultaneously solve poor water solubility, low bioavailability, and significant adverse reactions, this invention provides a 3-substituted ursolic acid difluoromethyl ester, its preparation method, and its uses. By introducing specific substituent groups at the 3-hydroxyl and 17-carboxyl groups of ursolic acid, specific substituent groups are introduced to simultaneously improve the water solubility of ursolic acid, enhance its in vivo bioavailability, prolong its retention time in vivo, and effectively reduce its gastrointestinal adverse reactions, thereby better meeting the practical application needs in the pharmaceutical field.

[0007] To enhance the activity of ursolic acid, the inventors introduced fluorine into the carboxyl group of ursolic acid to obtain ursolic acid difluoromethyl ester. Then, they etherified the 3-hydroxyl group of ursolic acid difluoromethyl ester to obtain a new class of 3-substituted ursolic acid difluoromethyl esters, thereby improving the activity of ursolic acid derivatives to meet the needs of clinical drug use.

[0008] The 3-substituted ursolic acid difluoromethyl ester compound of the present invention has the general structural formula shown in formula (I):

[0009] (I),

[0010] In formula (I), R is selected from hydrogen, C1-C9 alkyl, C2-C6 alkynyl, C2-C6 alkenyl, C3-C8 cycloalkyl or aralkyl (more preferably C1-C9 straight-chain or branched alkyl), the 3-position hydroxyl group is etherified to -OR, and the 28-position carboxyl group is modified to difluoromethyl ester (-COOCF2H).

[0011] Furthermore, the 3-substituted ursolic acid difluoromethyl ester compound is selected from one of the following compounds:

[0012] 3-Methoxy-ursolic acid difluoromethyl ester, 3-ethoxy-ursolic acid difluoromethyl ester, 3-propoxy-ursolic acid difluoromethyl ester, 3-pentoxy-ursolic acid difluoromethyl ester, 3-nonoxy-ursolic acid difluoromethyl ester.

[0013] The preparation method of the above compound includes the following steps:

[0014] S1. Following the method disclosed in the literature (Thanassi, JWJ Org. Chem. 1960, 25, 2009), ursolic acid A was reacted with HCF2Cl under the action of a catalyst and solvent to obtain intermediate B.

[0015] The reaction formula is as follows:

[0016] ,

[0017] The reaction temperature is 5~95℃, and the reaction time is 1~24 hours;

[0018] The solvent is selected from at least one of ethanol, methanol, or water, preferably water;

[0019] The catalyst is selected from at least one of KOH, NaOH or Ca(OH)2, preferably NaOH.

[0020] S2, intermediate B and alkylating agent RX undergo 3-position hydroxyl etherification reaction under the action of catalyst and solvent to obtain compound of general formula (I), in which X is halogen and R is selected from hydrogen, C1-C9 alkyl, C2-C6 alkynyl, C2-C6 alkenyl, C3-C8 cycloalkyl or aralkyl.

[0021] The reaction formula is as follows:

[0022] ,

[0023] The reaction temperature is 0~100℃, and the reaction time is 1~36 hours;

[0024] The solvent is selected from at least one of acetone, diethyl ether, ethanol, and methanol, with acetone being preferred;

[0025] The catalyst is selected from KCO3 or DMF, with KCO3 being preferred.

[0026] The following pharmacological experiments were conducted on the compounds of the present invention:

[0027] Antitumor effects include in vivo and in vitro experiments. In vitro experiments used the MTT and SRB methods to detect that compounds of general formula (I) exhibit significant cytotoxic activity, with an IC50 value of [missing information]. 50 The concentration range is 0.05–25.0 nM. In vivo experiments were conducted as follows: Intraperitoneal injection of the compound of general formula (I) into Lewis lung tumor-bearing mice for 9 consecutive days significantly inhibited the growth of Lewis lung tumors, with an inhibition rate of 91.3%. Intraperitoneal injection of 0.5–25 mg / kg of the compound of general formula (I) inhibited the growth of subcutaneously inoculated S-180 tumors in ICR-Jc1 mice, with a half-maximal inhibitory concentration (IC50) of 0.1–10 mg / kg.

[0028] In terms of antibacterial activity: Compounds of general formula (I) have significant antibacterial activity, with a MIC of 0.0016-19.25 μg / ml.

[0029] Regarding blood sugar reduction: After oral administration of 0.1-40 mg / Kg of compound of general formula (I) for 7 days, blood glucose concentration was measured and found that compound of general formula (I) could reduce blood glucose concentration by 39.5-90.1%.

[0030] Acute toxicity test: Mice were administered a single high dose of the compound of formula (I) via gavage. Behavioral activity and the degree of toxicity were continuously observed. Mice were euthanized at the end of the experiment for necropsy to obtain toxicity data for the compound of formula (I). After 14 days of continuous observation, no significant behavioral abnormalities or deaths were observed in the mice. The highest dose set in the experiment, 1000 mg / kg, and doses below this level showed no significant toxicity to the mice.

[0031] Pharmacological experiments have demonstrated that the compounds of this invention have varying degrees of antitumor, hypoglycemic, and antibacterial effects, and exhibit low toxicity.

[0032] Therefore, the compounds and their salts of the present invention can be used to prepare drugs for antitumor (mainly lung cancer, gastric cancer, prostate cancer, cervical cancer or breast cancer), hypoglycemic, and antibacterial (antibacterial includes antibacterial and / or antifungal, bacteria include at least one of Staphylococcus, Streptococcus or Escherichia coli, fungi include at least one of Candida albicans and Cryptococcus neoformans).

[0033] The compounds of the present invention can be administered to patients in need of treatment in the form of a composition comprising a therapeutically effective amount of the compounds of the present invention, their salts, and a pharmaceutically acceptable carrier, said carrier including diluents (such as water), fillers (such as lactose, starch), binders (such as polyvinylpyrrolidone), lubricants (such as magnesium stearate, talc), etc., and prepared into capsules by methods known in the art (such as direct powder filling or wet granulation filling), or into other dosage forms such as tablets, pills, granules, syrups, emulsions, suspensions, and solutions, administered conventionally, preferably orally, at a dose of 0.001 to 30 mg / kg body weight.

[0034] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0035] (1) This invention specifically modifies the characteristic sites of ursolic acid, significantly improving water solubility, increasing absorption and bioavailability, and prolonging the retention time in the body. At the same time, it reduces gastrointestinal irritation and adverse reactions, thus simultaneously improving the core defects and overcoming the technical problem of existing technologies that only optimize a single defect and cannot take into account multiple defects.

[0036] (2) The present invention adopts a specific directional modification process, which optimizes the physicochemical properties and safety while fully preserving the original multiple pharmacological activities of ursolic acid, such as antibacterial, antitumor, and hepatoprotective effects, thus avoiding the problem of loss of efficacy caused by conventional modification.

[0037] (3) The preparation process of this invention is simple and mild, requiring no high-risk equipment or expensive reagents, effectively reducing preparation costs. It also has good reaction orientation, few by-products, high product yield and purity, and good reproducibility, which is conducive to large-scale industrial production.

[0038] (4) The compounds obtained by this invention have excellent biocompatibility and high safety. They can be used to prepare a variety of pharmaceutical preparations and can also be used as cosmetic raw materials. They are widely used and safe, and have outstanding practical value. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to specific embodiments, but the present invention is not limited thereto.

[0040] In the following examples, unless otherwise specified, all raw materials and reagents are commercially available conventional products and are of analytical grade.

[0041] Example 1 Preparation of 3-methoxy-ursolic acid difluoromethyl ester (101)

[0042] Step 1: Preparation of intermediate B of ursolic acid difluoromethyl ester

[0043] Raw material pretreatment: Take 10.0 g of ursolic acid raw material (purity ≥98%, CAS: 77-52-1) and purify it by ethanol recrystallization: Take 50 mL of anhydrous ethanol, heat to 70 °C, add ursolic acid raw material, stir until completely dissolved, cool to 25 °C and stand for 2 h, filter, and vacuum dry at 60 °C for 2 h to obtain purified ursolic acid. Add 50 mL of methanol to the purified ursolic acid, control the temperature at 30 °C, stir for 30 min until completely dissolved, and obtain ursolic acid stock solution.

[0044] The above-mentioned ursolic acid stock solution was added to the reaction flask, followed by 0.8 g of sodium hydroxide (NaOH) as a catalyst. 100 mL of water was added as solvent, and HCF₂Cl gas was introduced under stirring. The reaction temperature was controlled at 50 °C, and the reaction was carried out for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, extracted three times with dichloromethane, and the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain ursolic acid difluoromethyl ester intermediate B. The structure of intermediate B is characterized as follows:

[0045] MS (EI, 70ev) m / z: 506; Anal. Calcd. for C 31 H 48 F2O3: C, 73.48; H, 9.55; F, 7.50; O, 9.47.

[0046] Step 2: Preparation of 3-methoxy-ursolic acid difluoromethyl ester

[0047] Intermediate B (5.06 g), acetone (100 mL), and potassium carbonate (K₂CO₃) (2.76 g) were added to a reaction flask. After thorough mixing, 1.42 g of iodomethane was added, and the mixture was refluxed at 56 °C for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, filtered to remove inorganic salts, and the acetone was recovered from the filtrate under reduced pressure. The residue was purified by silica gel column chromatography to obtain 3-methoxy-ursolic acid difluoromethyl ester (labeled 101). Its structural characterization data are as follows:

[0048] MS (EI, 70ev) m / z: 520; Anal. Calcd. for C 32 H 50 F2O3: C, 73.80; H, 9.69; F, 7.31; O, 9.20.

[0049] Example 2 Preparation of 3-ethoxy-ursolic acid difluoromethyl ester (102)

[0050] The rest is the same as in Example 1, except that bromoethane is used instead of iodomethane to obtain 3-ethoxy-ursolic acid difluoromethyl ester (labeled 102), whose structural characterization data are as follows:

[0051] MS (EI, 70ev) m / z: 534; Anal. Calcd. for C 33 H 52 F2O3: C, 74.12; H, 9.80; F, 7.11; O, 8.98.

[0052] Example 3 Preparation of 3-propoxy-ursolic acid difluoromethyl ester (103)

[0053] The rest is the same as in Example 1, except that bromopropane is used instead of iodomethane to obtain 3-propoxy-ursolic acid difluoromethyl ester (labeled 103), whose structural characterization data are as follows:

[0054] MS (EI, 70ev) m / z: 548; Anal. Calcd. for C 34 H 54 F2O3: C, 74.40; H, 9.93; F, 6.93; O, 8.74.

[0055] Example 4 Preparation of 3-pentoxy-ursolic acid difluoromethyl ester (104)

[0056] The rest is the same as in Example 1, except that bromopentane is used instead of iodomethane to obtain 3-pentoxy-ursolic acid difluoromethyl ester (labeled 104), whose structural characterization data are as follows:

[0057] MS (EI, 70ev) m / z: 548; Anal. Calcd. for C 36 H 58 F2O3: C, 74.96; H, 10.12; F, 6.59; O, 8.33.

[0058] Example 5 Preparation of 3-nonoxy-ursolic acid difluoromethyl ester (105)

[0059] The rest is the same as in Example 1, except that nonane bromo isomethyl iodide is used instead of iodomethane to obtain 3-nonoxy-ursolic acid difluoromethyl ester (labeled 105), whose structural characterization data are as follows:

[0060] MS (EI, 70ev) m / z: 548; Anal. Calcd. for C 40 H 66 F2O3: C, 75.90; H, 10.50; F, 6.01; O, 7.58.

[0061] Example 6: Test of the antitumor activity of the compounds of the present invention

[0062] The in vitro inhibitory activity of some compounds of the present invention against gastric cancer, prostate cancer, cervical cancer, lung cancer and breast cancer cells was determined by the MTT assay reported by Mosman (Mosman, TJ Immunol Methods. 1983, 65, 55). The experimental results are shown in Table 1.

[0063] Specific procedures: Tumor cells in the logarithmic growth phase were digested with trypsin and prepared into a cell suspension. This suspension was then seeded into 96-well culture plates and incubated at 37°C with 5% CO2 for 24 hours. The test compound was dissolved in DMSO and diluted to a series of concentrations. Positive and blank controls were also included. After 48 hours of further incubation, 20 μL of 5 mg / mL MTT solution was added to each well, and incubation continued for another 4 hours. The culture was terminated, the supernatant was carefully aspirated, and 150 μL of DMSO was added to each well. The mixture was shaken for 10 minutes to ensure complete dissolution of the formazan. The absorbance (OD value) at 570 nm was measured using a microplate reader. The cell inhibition rate and the half-maximal inhibitory concentration (IC50) were calculated. 50 ).

[0064] Experimental Results: The compounds of this invention exhibit excellent inhibitory activity against the aforementioned tumor cells, as shown in Table 1. Table 1 shows that compound 101 has an IC50 value against gastric cancer cells. 50 The value was 0.25 nM, and the IC50 value was 0.25 nM for prostate cancer, cervical cancer, lung cancer, and breast cancer cells. 50The values ​​were 1.75 nM, 9.86 nM, 6.03 nM, and 22.12 nM, respectively, demonstrating extremely high selective inhibitory activity against gastric cancer cells. Compound 102 showed IC50 values ​​against gastric and lung cancer cells. 50 The values ​​were 0.07 nM and 1.05 nM, respectively, showing extremely strong inhibitory effects; the IC50 values ​​against prostate cancer, cervical cancer, and breast cancer cells were also observed. 50 The values ​​were 17.31 nM, 21.16 nM, and 7.42 nM, respectively. The IC50 values ​​of compound 104 against various tumor cell lines were... 50 Values ​​ranged from 1.07 nM to 5.52 nM, with stronger inhibitory activity against lung cancer and breast cancer (IC50). 50 The concentrations were 1.07 nM and 2.85 nM, respectively. These results indicate that the compounds of this invention possess broad-spectrum antitumor activity, particularly exhibiting extremely high sensitivity against certain tumor cell lines.

[0065] Table 1

[0066]

[0067] Example 7: Antibacterial activity test of the compounds of the present invention

[0068] Experimental Methods: Refer to the literature (Zhang Juntian, ed., *Modern Pharmacological Experimental Methods*). The minimum inhibitory concentration (MIC) of some compounds of this invention against Staphylococcus, Streptococcus, Escherichia coli, Candida albicans, and Cryptococcus neoformans was determined using the micro-liquid dilution method. Specific procedures: The test compounds were dissolved and diluted to a series of concentrations using DMSO. Each concentration of solution was added to a 96-well plate, and freshly prepared bacterial suspension (bacterial concentration approximately 1 × 10⁻⁶) was added to each well. 5 CFU / mL, fungal concentration approximately 1×10⁻⁶ 4 The concentration of the drug was calculated to be CFU / mL, resulting in a final drug volume of 200 μL. Bacteria were cultured at 37°C for 24 h, and fungi at 28°C for 48 h. The lowest drug concentration at which no bacterial or fungal growth was observed visually was defined as the MIC value. Positive and blank controls were also included.

[0069] Experimental Results: The compounds of this invention exhibited varying degrees of antibacterial activity against the aforementioned strains, as shown in Table 2. Table 2 shows that compound 102 had MIC values ​​of 0.0025 μg / mL and 0.0035 μg / mL against *Escherichia coli* and *Candida albicans*, respectively, demonstrating extremely strong inhibitory effects; it also showed strong activity against *Cryptococcus neoformans* with an MIC value of 0.18 μg / mL. Compound 103 had MIC values ​​of 0.11 μg / mL and 0.013 μg / mL against *Staphylococcus* and *Streptococcus*, respectively, but its activity against fungi was relatively weak. Compound 105 exhibited excellent antifungal activity with an MIC value of 0.0075 μg / mL against *Cryptococcus neoformans*. These results indicate that the compounds of this invention possess broad-spectrum antibacterial activity, especially showing extremely high sensitivity against certain strains.

[0070] Table 2. Antimicrobial activity (MIC) results of the compounds of this invention.

[0071]

[0072] Example 8: Test of the antidiabetic activity of the compounds of the present invention

[0073] Experimental Methods: Male ICR mice were fasted for 12 hours and randomly divided into a blank control group, a positive control group (metformin 250 mg / kg), and different dose groups of the test compound, with 10 mice in each group. Basal blood glucose was measured 30 minutes after gavage administration of the test compound, followed by gavage administration of glucose (2 g / kg). Blood samples were collected from the tail vein at 30, 60, 90, and 120 minutes after glucose administration, and blood glucose levels were measured using the glucose oxidase method. The hypoglycemic effect of the compound was evaluated based on the hypoglycemic rate (based on the peak blood glucose level 30 minutes after glucose administration).

[0074] Experimental Results: The compounds of this invention exhibited significant antidiabetic activity in the oral glucose tolerance test. Compound 101 reduced glucose by 75.3% at a dose of 20 mg / kg; compound 103 reduced glucose by 60.2% at a dose of 40 mg / kg; compound 104 reduced glucose by 83.5% at a dose of 120 mg / kg; and compound 105 reduced glucose by as much as 89.3% at a dose of 200 mg / kg. The positive control, metformin (250 mg / kg), reduced glucose by approximately 50%–70%.

[0075] Example 9 Tablet Composition and Preparation Method Thereof

[0076] This embodiment provides a tablet of a compound of general formula (I), specifically comprising the following components:

[0077] Compound of general formula (I) (specifically compound 101 prepared in Example 1) 125 mg

[0078] Magnesium stearate 5mg

[0079] 5mg talc

[0080] 40mg lactose

[0081] Starch 30mg

[0082] Sodium carboxymethyl starch 15mg

[0083] Microcrystalline cellulose 30mg

[0084] The tablets can be prepared using either direct powder compression or wet granulation compression.

[0085] Direct powder compression method: The active ingredient, filler (lactose, starch, microcrystalline cellulose), disintegrant (sodium carboxymethyl starch), etc. are mixed evenly and then directly compressed into tablets. Wet granulation compression method: The active ingredient and filler are mixed, a binder solution is added for granulation, dried, and then mixed with a lubricant (magnesium stearate, talc) for compression into tablets.

[0086] This embodiment preferably uses wet granulation and tableting, and the specific steps are as follows:

[0087] (1) Pretreatment: Pass the active ingredients through a 100-mesh sieve.

[0088] (2) Mixing and granulation: Mix the sieved active ingredients with lactose and microcrystalline cellulose evenly, add an appropriate amount of purified water to make a soft material, and granulate it through a 20-mesh sieve.

[0089] (3) Drying and granulation: wet granules are dried at 50℃ and the dry granules are granulated by passing them through a 20-mesh sieve.

[0090] (4) Total mixture and tableting: Add magnesium stearate and talc powder, mix and compress to obtain tablets.

[0091] Example 10 Capsule Composition and Preparation Method Thereof

[0092] This embodiment provides a capsule formulation of a compound of general formula (I), specifically comprising the following components:

[0093] 120 mg of compound of general formula (I) (specifically compound 103 prepared in Example 3)

[0094] Magnesium stearate 5mg

[0095] 10mg talc

[0096] Lactose 60mg

[0097] Starch 30mg

[0098] Polyvinylpyrrolidone 10mg

[0099] The capsules can be prepared using either direct powder filling or wet granulation filling.

[0100] Direct powder filling method: Mix the active ingredients and fillers (lactose, starch) evenly, add lubricants (magnesium stearate, talc) and mix thoroughly, then directly fill into the capsule shell.

[0101] Wet granulation and filling method: The active ingredient is mixed with the filler, polyvinylpyrrolidone solution is added for granulation, dried and then mixed with a lubricant to fill capsules.

[0102] This embodiment preferably uses wet granulation and filling, and the specific steps are as follows:

[0103] (1) Pretreatment: Pass the active ingredients through a 100-mesh sieve.

[0104] (2) Mixing and granulation: Mix the sieved active ingredients with lactose and starch evenly, add an appropriate amount of aqueous solution of polyvinylpyrrolidone to make a soft material, and granulate it through a 20-mesh sieve.

[0105] (3) Drying and granulation: wet granules are dried at 50℃ and the dry granules are granulated by passing them through a 20-mesh sieve.

[0106] (4) Total mixture filling: Add magnesium stearate and talc powder to the mixture and fill it into a suitable capsule shell.

[0107] In summary, this invention successfully prepared the aforementioned 3-substituted ursolic acid difluoromethyl ester compounds through directional structural modification of ursolic acid by etherification at the 3-position and difluoromethylation at the 28-position. These compounds not only significantly improve upon the inherent defects of ursolic acid, such as poor water solubility, low bioavailability, and high gastrointestinal irritation, but also exhibit potent broad-spectrum antitumor, significant antibacterial, and highly effective hypoglycemic activities, with low acute toxicity and high safety. Furthermore, the preparation process of this invention is mild, simple, uses readily available raw materials, and is inexpensive, making it suitable for industrial-scale production. The resulting compounds can be widely applied in the development of antitumor, antibacterial, and hypoglycemic drugs, providing new candidate molecules and technical support for the high-value utilization of the natural product ursolic acid and the development of innovative drugs.

Claims

1. A 3-substituted ursolic acid difluoromethyl ester compound, characterized in that, It has the general formula shown in equation (I): （I）， In formula (I), R is selected from hydrogen, C1-C9 alkyl, C2-C6 alkynyl, C2-C6 alkenyl, C3-C8 cycloalkyl or aralkyl, the 3-hydroxyl group is etherified to -OR, and the 28-carboxyl group is modified to difluoromethyl ester.

2. The compound according to claim 1, characterized in that, R is a C1-C9 straight-chain or branched alkyl group.

3. The compound according to claim 1, characterized in that, The 3-substituted ursolic acid difluoromethyl ester compound is selected from one of the following compounds: 3-methoxy-ursolic acid difluoromethyl ester, 3-ethoxy-ursolic acid difluoromethyl ester, 3-propoxy-ursolic acid difluoromethyl ester, 3-pentoxy-ursolic acid difluoromethyl ester, and 3-nonoxy-ursolic acid difluoromethyl ester.

4. A method for preparing the compound according to any one of claims 1-3, characterized in that, Includes the following steps: S1. Ursolic acid reacts with HCF2Cl in the presence of a catalyst and solvent to obtain ursolic acid difluoromethyl ester intermediate B. S2, intermediate B and alkylating agent RX undergo 3-position hydroxyl etherification reaction in the presence of a catalyst and solvent to obtain compound of general formula (I), in which X is a halogen and R is selected from hydrogen, C1-C9 alkyl, C2-C6 alkynyl, C2-C6 alkenyl, C3-C8 cycloalkyl or aralkyl.

5. The preparation method according to claim 4, characterized in that, In step S1, the solvent is selected from at least one of water, methanol, and ethanol, the catalyst is selected from at least one of NaOH, KOH, and Ca(OH)2, the reaction temperature is 5~95℃, and the reaction time is 1~24 hours.

6. The preparation method according to claim 4, characterized in that, In step S2, the solvent is selected from at least one of acetone, diethyl ether, methanol, and ethanol, the catalyst is selected from K2CO3 or DMF, the reaction temperature is 0~100℃, and the reaction time is 1~36 hours.

7. A pharmaceutical composition, characterized in that, It comprises the compound of any one of claims 1 to 3 or a pharmaceutically acceptable salt thereof, and at least one pharmaceutically acceptable carrier.

8. The pharmaceutical composition according to claim 7, characterized in that, Dosage form is selected from tablets, capsules, granules, pills, syrups, emulsions, suspensions or solutions.

9. The use of the compound according to any one of claims 1 to 3 in the preparation of an antitumor drug, characterized in that, The tumor is selected from lung cancer, stomach cancer, prostate cancer, cervical cancer, or breast cancer.

10. The use of the compound according to any one of claims 1 to 3 in the preparation of hypoglycemic drugs or antibacterial drugs, characterized in that, The antibacterial properties include antibacterial and / or antifungal properties, wherein the bacteria include at least one of Staphylococcus, Streptococcus or Escherichia coli, and the fungi include at least one of Candida albicans and Cryptococcus neoformans.

Images