Application of dihydrochalcone compounds in preparation of medicines for resisting skin pigmentation or reducing uric acid

Abstract

The invention relates to the technical field of medicines, and discloses an application of a dihydrochalcone compound in preparation of a medicine for resisting skin pigmentation or reducing uric acid, the structural formula of the dihydrochalcone compound is as shown in formula I. In the formula I, R1 is tert-butyl or hydrogen; r2 is ethyl, propyl, chlorine, fluorine, hydrogen or tertiary butyl; and R3 and R4 are respectively hydroxyl or benzyloxy. The compound has obvious in-vitro skin pigmentation disease resistance activity, has strong tyrosinase inhibition capability on B16F10 mouse melanoma cells, has good xanthine oxidase (XOD) inhibition activity, can obviously reduce uric acid in an HK-2 hyperuricemia cell model, and has good potential medicinal value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medicine, in particular to the application of dihydrochalcone compounds in the preparation of drugs for resisting skin pigmentation or reducing uric acid. BACKGROUND

[0002] The statements herein are provided only to enhance understanding of the present application and are not necessarily intended to constitute the prior art.

[0003] Skin pigmentation diseases (such as chloasma, post-inflammatory hyperpigmentation, Riehl melanosis, freckles, etc.) are caused by abnormal synthesis and secretion of melanin granules by melanocytes, and the incidence is closely related to genetic susceptibility, ultraviolet radiation, endocrine disorders and inflammatory reactions. Such diseases not only affect the appearance of patients, but also may cause psychological problems such as anxiety and depression, and reduce the quality of life. The commonly used drugs such as hydroquinone and kojic acid have defects such as strong irritation and easy drug resistance, which are difficult to meet the needs.

[0004] Hyperuricemia and its complications (gout, uric acid nephropathy) have become a global metabolic problem, and its incidence is closely related to high purine diet, alcohol intake, obesity and genetic susceptibility. By promoting oxidative stress, inflammatory response and metabolic disorders, it is closely related to the occurrence and development of hypertension, type 2 diabetes, cardiovascular disease and chronic kidney disease. The existing uric acid-lowering drugs (allopurinol, febuxostat, benzbromarone) have the risk of allergy, cardiovascular controversy or drug contraindications, and the development of new drugs is imminent. SUMMARY

[0005] In view of the deficiencies in the prior art, the purpose of the present application is to provide the application of dihydrochalcone compounds in the preparation of drugs for resisting skin pigmentation or reducing uric acid.

[0006] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme: In the first aspect, the present application provides the application of dihydrochalcone compounds in any of the following: 1) preparation of drugs for resisting skin pigmentation; 2) preparation of drugs for reducing uric acid; the structural formula of the dihydrochalcone compound is shown as formula I: ; In formula I, R1 is tert-butyl or hydrogen; R2 is ethyl, propyl, chlorine, fluorine, hydrogen or tert-butyl; R3 and R4 are hydroxyl or benzyloxy, respectively.

[0007] In the second aspect, the present application provides a pharmaceutical composition for treating skin pigmentation or reducing uric acid, which comprises the dihydrochalcone compound and adjuvants.

[0008] The beneficial effects achieved by one or more embodiments of the present application are as follows: The compound has significant in-vitro anti-skin pigmentation disease activity, strong tyrosinase inhibiting ability on B16F10 mouse melanoma cells, good xanthine oxidase (XOD) inhibiting activity, and significantly reduces uric acid in a HK-2 high uric acid cell model, has good potential medicinal value, and can be used for preparation of various anti-skin pigmentation disease or uric acid reducing drugs. BRIEF DESCRIPTION OF DRAWINGS

[0009] The accompanying drawings, which form a part of the specification, are included to provide a further understanding of the application and are incorporated herein in conjunction with the description of the application. The embodiments of the present application, together with its advantages, can best be understood by referring to the following description taken in conjunction with the accompanying drawings in which:

[0010] Figure 1 A nuclear magnetic resonance hydrogen spectrum of a product prepared in Example 1 of the present application; Figure 2 A nuclear magnetic resonance carbon spectrum of the product prepared in Example 1 of the present application; Figure 3 A high performance liquid chromatogram of the product prepared in Example 1 of the present application; Figure 4 A nuclear magnetic resonance hydrogen spectrum of a product prepared in Example 2 of the present application; Figure 5 A nuclear magnetic resonance carbon spectrum of the product prepared in Example 2 of the present application; Figure 6 A high performance liquid chromatogram of the product prepared in Example 2 of the present application; Figure 7 A nuclear magnetic resonance hydrogen spectrum of a product prepared in Example 3 of the present application; Figure 8 A nuclear magnetic resonance carbon spectrum of the product prepared in Example 3 of the present application; Figure 9 A high performance liquid chromatogram of the product prepared in Example 3 of the present application; Figure 10 A nuclear magnetic resonance hydrogen spectrum of a product prepared in Example 4 of the present application; Figure 11 A nuclear magnetic resonance carbon spectrum of the product prepared in Example 4 of the present application; Figure 12 A high performance liquid chromatogram of the product prepared in Example 4 of the present application; Figure 13 A nuclear magnetic resonance hydrogen spectrum of a product prepared in Example 5 of the present application; Figure 14 A nuclear magnetic resonance carbon spectrum of the product prepared in Example 5 of the present application; Figure 15 A high performance liquid chromatogram of the product prepared in Example 5 of the present application; Figure 16 A nuclear magnetic resonance hydrogen spectrum of a product prepared in Example 6 of the present application; Figure 17 The nuclear magnetic resonance carbon spectrum of the product obtained in Example 6 of this invention; Figure 18 This is a high-performance liquid chromatogram of the product obtained in Example 6 of the present invention. Detailed Implementation

[0011] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0012] This invention provides the application of dihydrochalcone compounds in any of the following: 1) preparation of anti-skin pigmentation drugs; 2) preparation of uric acid-lowering drugs; the structural formula of the dihydrochalcone compound is shown in Formula I: ; In Formula I, R1 is tert-butyl or hydrogen; R2 is ethyl, propyl, chlorine, fluorine, hydrogen or tert-butyl; R3 and R4 are hydroxyl or benzyloxy, respectively.

[0013] The above compounds exhibit strong inhibitory activity against tyrosinase in B16F10 mouse melanoma cells and significant in vitro anti-pigmentation activity; they also show good inhibitory activity against xanthine oxidase (XOD) and can significantly reduce uric acid levels in the HK-2 hyperuricemia cell model, demonstrating highly effective targeted therapy.

[0014] In some embodiments, the dihydrochalcone compound is selected from at least one of the following compounds: .

[0015] In some embodiments, the method for preparing the dihydrochalcone compound includes the following steps: ; In step a, compound III and compound II undergo an aldol condensation reaction under base catalysis to prepare compound IV; Step b: Prepare a solution of compound IV, introduce hydrogen gas into it, and catalytically hydrogenate to obtain compound I.

[0016] Preferably, the molar ratio of compound III to compound II is 1:1-1.2, and more preferably 1:1.05.

[0017] Preferably, in step a, the base is sodium hydroxide or potassium hydroxide, and the molar ratio of the base to compound III is 2-6:1.

[0018] Preferably, step a further includes the steps of extraction, vacuum distillation, and purification of the reaction solution. The extraction method is as follows: first, extract with ethyl acetate at least twice, collect the organic phase, and then wash the organic phase with saturated brine. The purpose of extraction with saturated brine here is to reduce the solubility of the product in the organic phase (ethyl acetate) in water, thereby reducing the loss of the target compound; at the same time, wash away residual water-soluble impurities in the organic phase (such as excess sodium hydroxide, reaction byproducts, etc.), and promote the separation of the organic and aqueous phases through the salting-out effect, thereby improving the efficiency of subsequent drying and purification steps.

[0019] More preferably, in step a, the purification method is recrystallization using ethanol.

[0020] Preferably, the reaction temperature in step a is 75-85℃ and the reaction time is 2-4h.

[0021] Preferably, the reaction temperature in step b is 25-35℃ and the reaction time is 1-2h.

[0022] Preferably, the catalyst used in step b is palladium hydroxide / carbon.

[0023] Preferably, step b further includes a step of vacuum distillation and purification of the reacted solution, wherein the purification method is silica gel column chromatography, and the eluent is a mixture of petroleum ether and ethyl acetate in a volume ratio of 25-35:1.

[0024] The present invention provides a pharmaceutical composition for treating skin pigmentation and / or lowering uric acid, comprising the dihydrochalcone compound and excipients.

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] Example 1 This embodiment provides a dihydrochalcone compound, 2,4-dihydroxy-4'-chlorodihydrochalcone, containing a resorcinol structure as shown in Formula I-1.

[0027]

[0028] The method for synthesizing the above-mentioned dihydrochalcone compounds containing a resorcinol structure includes the following steps: Step a: Compound III (3.1 mmol, 1.0 eq) was dissolved in 100 mL of ethanol, sodium hydroxide (15.7 mmol, 5.0 eq) was added, the mixture was stirred, and 4-chloroacetophenone (3.3 mmol, 1.05 eq) was added dropwise. After the addition was complete, the mixture was heated to reflux at 80 °C for 3 hours. The reaction mixture was quenched with ice water, the aqueous phase was extracted three times with ethyl acetate, the organic phase was retained, the organic phase was washed once with saturated sodium chloride solution, dried over anhydrous sodium sulfate, the solvent was removed by vacuum distillation, and 20 mL of ethanol was added for recrystallization to give intermediate IV-1 (1.4 g, yield 93.9%, purity 98.8%).

[0029] Step b: Intermediate IV-1 (0.1 mmol, 1.0 eq) was dissolved in 5 mL of dichloromethane, hydrogen gas was introduced, palladium hydroxide / carbon was added, and the mixture was stirred and reacted at room temperature for 1.5 hours. The palladium hydroxide / carbon was removed by filtration, the solvent was removed by vacuum distillation, and the product was purified by silica gel column chromatography (PE / EA = 30:1) to obtain the target compound (28.6 mg, yield 94.2%, purity 98.7%), as shown in Formula I-1. The 1H NMR spectrum of the target compound is shown below. Figure 1 As shown, the carbon NMR spectrum is as follows: Figure 2 As shown, the high-performance liquid chromatogram is as follows: Figure 3 As shown, Figure 3 The integration results are shown in Table 1.

[0030] Table 1 Figure 3 Table of integrated results of medium liquid chromatogram

[0031] Examples 2 to 6 Examples 2 to 6 provide a dihydrochalcone compound containing a resorcinol structure as shown in Formula I-2 to Formula I-6, namely Compound I-2 to Compound I-6.

[0032] The synthesis method of the above-mentioned dihydrochalcone compounds containing resorcinol structure is similar to that of Example 1, except that acetophenone in step a is replaced accordingly, and the remaining steps are the same as in Example 1, and will not be repeated here.

[0033] It should be noted that the molecular weight of the target compound was determined by Q-TOF-HRMS with a mobile phase of 100% acetonitrile solution and a flow rate of 0.1 mL / min. The NMR and mass spectrometry data of dihydrochalcone compounds containing resorcinol structures are shown in Table 7.

[0034] The proton NMR spectrum of the compound of formula I-2 prepared in Example 2 is shown below. Figure 4 As shown, the carbon NMR spectrum is as follows:Figure 5 As shown, the high-performance liquid chromatogram is as follows: Figure 6 As shown in Table 2, the integration results are as follows; Table 2 Figure 6 Table of integrated results of medium liquid chromatogram

[0035] The proton NMR spectrum of the compound of formula I-3 prepared in Example 3 is shown below. Figure 7 As shown, the carbon NMR spectrum is as follows: Figure 8 As shown, the high-performance liquid chromatogram is as follows: Figure 9 As shown, the integration results are shown in Table 3; Table 3 Figure 9 Table of integrated results of medium liquid chromatogram

[0036] The proton NMR spectrum of the compound of formula I-4 prepared in Example 4 is shown below. Figure 10 As shown, the carbon NMR spectrum is as follows: Figure 11 As shown, the high-performance liquid chromatogram is as follows: Figure 12 As shown, the integration results are shown in Table 4; Table 4 Figure 12 Table of integrated results of medium liquid chromatogram

[0037] The proton NMR spectra of the compounds of formula I-5 prepared in Example 5 are as follows: Figure 13 As shown, the carbon NMR spectrum is as follows: Figure 14 As shown, the high-performance liquid chromatogram is as follows: Figure 15 As shown, the integration results are shown in Table 5; Table 5 Figure 15 Table of integrated results of medium liquid chromatogram

[0038] The proton NMR spectra of the compounds of formula I-6 prepared in Example 6 are as follows: Figure 16 As shown, the carbon NMR spectrum is as follows: Figure 17 As shown, the high-performance liquid chromatogram is as follows: Figure 18 As shown in Table 6, the integration results are as follows; Table 6 Figure 18 Table of integrated results of medium liquid chromatogram

[0039] Table 7. NMR and mass spectrometry data of the target compounds in Examples 1-6

[0040] Pharmacological activity experiment examples Antioxidant activity determination of compounds in Examples 1-6: Experimental methods (1) In a 96-well plate, 180 μL of DPPH methanol solution (0.2 mM) and 20 μL of representative compounds (compounds I-1 to I-6 were prepared to 100 μM using DMSO) were mixed. L-ascorbic acid was used as a standard reference, and 20 μL of DMSO was added to the blank group; (2) Then the 96-well plate was incubated in the dark for 1 hour, and the absorbance was measured at 517 nm using an enzyme-linked immunosorbent assay (ELISA) reader. All experiments were repeated three times.

[0041] The DPPH radical scavenging activity of the representative compound is calculated using the following formula: Radical scavenging rate % = [(Ac-As) / Ac] × 100%, where Ac refers to the absorbance of the blank group and As refers to the absorbance of the test group.

[0042] The test results are shown in Table 8.

[0043] Table 8. Results of antioxidant activity tests on compounds from Examples 1 to 6 at 100 μM.

[0044] The data in Table 8 show that all tested compounds exhibited significant DPPH free radical scavenging ability at a concentration of 100 μM, with scavenging rates ranging from 63.80% to 76.35%. Among them, Example 3 showed the most outstanding activity, reaching 76.35%, which is close to the effect of the positive control L-ascorbic acid (82.02%). This preliminarily suggests that these compounds have the potential to alleviate oxidative stress, which is one of the common pathogenesis mechanisms of skin pigmentation and hyperuricemia.

[0045] Cytotoxicity assays of the compounds in Examples 1-6 on B16F10 mouse melanoma cells: Experimental methods (1) B16F10 cells were used to represent the cytotoxicity analysis of compounds I-1 to I-6. Cells were cultured in DMEM high-glucose medium containing 10% fetal bovine serum. Cells in the logarithmic growth phase were digested, counted, and resuspended at 3 × 10⁻⁶ cells / cells. 3 Inoculate the cells per well into 96-well plates and culture.

[0046] (2) After culturing for 24 hours, different concentrations of the example (5 μM, 10 μM and 50 μM) were added to it, and it was incubated for another 72 hours in a 37°C, 5% CO2 incubator (the blank control group was given an equal amount of culture medium). Then, 20 μL of 5 mg / L MTT was added to it, and after culturing in the incubator for 4 hours, the culture medium was aspirated, and formazan was dissolved in 150 μL of DMSO. The absorbance at 490 nm was measured using an ELISA reader.

[0047] The experimental results are shown in Table 9.

[0048] Table 9. Cytotoxic effects of compounds from Examples 1-6 on B16F10.

[0049] Table 9 shows the toxicity of the compounds to B16F10 mouse melanoma cells assessed using the MTT assay. Within the concentration range of 5–50 μM, cell viability in all compound-treated groups remained above 90% compared to the blank control group (100%). Even at the high concentration of 50 μM, the lowest cell viability (Example 5, 90.66%) showed no significant toxicity. This indicates that the compounds are safe for the relevant cell models at concentrations exhibiting potent tyrosinase inhibitory activity, and that their antipigmentation activity is not due to cytotoxicity, ruling out false positives and enhancing the reliability of the experimental conclusions.

[0050] Tests of the inhibitory activity of compounds from Examples 1 to 6 on intracellular tyrosinase: Experimental methods (1) After digesting, resuspending, and counting B16F10 cells in the logarithmic growth phase, they were then subjected to 3 × 10⁻⁶ cells per cell. 4 Cells were seeded into 24-well plates at a rate of 1 cell per well and incubated in a 37°C, 5% CO2 incubator for 24 hours. The obtained cells were then divided into three groups: blank control group, positive control group, and experimental group. (2) 1 μM of α-melanocyte-stimulating hormone (α-MSH) was added to the blank control group, positive control group and experimental group. The positive control group was treated with 25 μM of kojic acid. The experimental group was treated with 5 μM, 10 μM and 25 μM of compound I-1 to compound I-6. DMSO (<0.3%) was added to the blank control group.

[0051] (3) After incubating the cells from each group treated in step (2) in an incubator for 24 hours, collect the cells into centrifuge tubes, wash the cells twice with 1 mL PBS, and then add 100 μM of 1% Triton X-100 containing 0.1 mM PMSF (prepared with 50 mM, pH = 6.8 PBS) to lyse the cells. After incubating at -80 ℃ for 30 minutes, allow them to thaw at room temperature, and then incubate at -4 ℃ for 1.2 × 10⁻⁶ cells / mL. 4 After centrifugation at rpm for 15 minutes, 80 μL of the supernatant was added to a 96-well plate, followed by 20 μL of L-Dopa (2 mM) substrate. The plate was then incubated at 37 °C for 1 hour, and the absorbance at 490 nm was measured every 10 minutes using a microplate reader. The experiment was repeated three times. Tyrosinase activity % = OD experimental group / OD blank control group × 100%.

[0052] The experimental results are shown in Table 10.

[0053] Table 10 Inhibitory activity of compounds from Examples 1 to 6 against tyrosinase

[0054] Tests on the inhibitory activity of compounds from Examples 1 to 6 on intracellular melanin content: Experimental methods (1) After digesting, resuspending, and counting B16F10 cells in the logarithmic growth phase, they were then subjected to 3 × 10⁻⁶ cells per cell. 4 Cells were seeded into 24-well plates at a rate of 1 cell per well and incubated in a 37 °C, 5% CO2 incubator for 24 hours. The obtained cells were then divided into three groups: blank control group, positive control group, and experimental group. (2) 1 μM of α-melanocyte-stimulating hormone (α-MSH) was added to the blank control group, positive control group and experimental group. The positive control group was treated with 25 μM of kojic acid. The experimental group was treated with 5 μM, 10 μM and 25 μM of compound I-1 to compound I-6 respectively. DMSO (<0.3%) was added to the blank control group. (3) After incubating the cells treated in step (2) in an incubator for 24 hours, the cells were collected into centrifuge tubes, washed twice with 1 mL PBS, and then 100 μM 1M NaOH was added. The cells were incubated at 60 °C for 1 hour. The supernatant was transferred to a 96-well plate and its absorbance at 405 nm was measured using an ELISA reader. The test results are shown in Table 6.

[0055] The experiment was repeated three times to reduce experimental error and ensure the accuracy and reliability of the results.

[0056] Melanin content % = OD experimental group / OD blank control group × 100%.

[0057] The experimental results are shown in Table 11.

[0058] Table 11. Inhibitory activity of compounds from Examples 1 to 6 on melanin content.

[0059] Table 11 directly measured the effects of the compounds on melanin production in B16F10 cells, providing the final phenotypic evidence of their anti-pigmentation activity. Consistent with the tyrosinase inhibition results, all compounds significantly and dose-dependently reduced intracellular melanin content at concentrations of 5–25 μM. At 25 μM, melanin content was inhibited to 60.65%–65.30% of the blank control, demonstrating effects superior to or comparable to the positive control kojic acid (75.31%), proving that these compounds possess clear anti-pigmentation efficacy at the cellular level.

[0060] Tests of the inhibitory activity of compounds from Examples 1 to 6 against xanthine oxidase (XOD): Experimental methods (1) Dissolve compounds I-1 to I-6 in DMSO to prepare a 10 mM stock solution for later use; (2) Use 0.067 M PBS with a pH of 6.8 to serially dilute the stock solution in step (1) to 5 μM, 10 μM and 25 μM; (3) The compounds of different concentrations in step (2) were incubated with 1 μM XOD at 37 °C for 15 minutes (the blank control group was added with an equal amount of PBS). Then, 1 μM substrate xanthine solution was added and pre-incubated at 37 °C for 10 minutes. The system was immediately placed in a microplate reader and the absorbance at 295 nm was detected. PBS solvent was used as a blank control. The measurements were performed three times in parallel. The results are shown in Table 7.

[0061] XOD activity % = OD experimental group / OD blank control group × 100%.

[0062] The experimental results are shown in Table 12.

[0063] Table 12 Inhibitory activity of compounds in Examples 1-6 against xanthine oxidase

[0064] Table 12 shifts the research focus to uric acid-lowering activity, evaluating the compounds' inhibitory ability on xanthine oxidase (XOD, a key enzyme in uric acid production). The results show that all compounds exhibit strong inhibitory effects on XOD at concentrations ranging from 5 to 25 μM, in a concentration-dependent manner. At 25 μM, the inhibition rates reached as high as 90.08% to 94.72%, with Example 3 showing the strongest activity. This indicates that these compounds can block uric acid production by directly inhibiting XOD, which is the clear mechanism by which they exert their uric acid-lowering effect.

[0065] The HK-2 human renal cortical proximal tubular epithelial cell toxicity assay of the compounds in Examples 1-6: Experimental methods (1) Cells were cultured in DMEM high-glucose medium containing 10% fetal bovine serum. Cells in the logarithmic growth phase were digested, counted, and resuspended at 3 × 10⁻⁶ cells / mL. 3 Inoculate the cells / wells into 96-well plates and culture them. (2) After culturing for 24 hours, different concentrations of compounds from Examples 1 to 6 (5 μM, 10 μM and 50 μM) were added to the culture medium. The culture was then continued for 72 hours in a 37 °C, 5% CO2 incubator. Then, 20 μL of 5 mg / L MTT was added to the culture medium. After culturing for 4 hours in the incubator, the culture medium was removed, and formazan was dissolved in 150 μL of DMSO. The absorbance at 450 nm was measured using an ELISA reader.

[0066] The experimental results are shown in Table 13.

[0067] Table 13 Cytotoxic effects of compounds in Examples 1-6 on HK-2 cells

[0068] Table 13 assessed the toxicity of the compounds to human renal cortical proximal tubular epithelial cells (HK-2), as the kidney is a vital organ for uric acid excretion, and uric acid-lowering drugs need to act safely in this site. Similar to the results in B16F10 cells, all compounds had no significant effect on the activity of HK-2 cells at concentrations ranging from 5 to 50 μM, with cell viability remaining above 92%. This demonstrates the excellent biocompatibility of the compounds in target organ-related cell models, supporting their safety as uric acid-lowering drugs.

[0069] Effects of Compounds from Examples 1-6 on Uric Acid Content in the HK-2 Hyperuricemia Cell Model: Experimental methods (1) After digesting, resuspending, and counting HK-2 cells in the logarithmic growth phase, they were then subjected to 3 × 10⁻⁶ cells / mL. 4Cells were seeded into 24-well plates at a rate of 1 cell per well and incubated in a 37 °C, 5% CO2 incubator for 24 hours. The obtained cells were then divided into three groups: blank control group, positive control group, and experimental group. (2) 1 μM adenosine was added to the blank control group, positive control group and experimental group. The positive control group was treated with 25 μM febuxostat. The experimental group was treated with 5 μM, 10 μM and 25 μM of compound I-1 to compound I-6. DMSO (<0.3%) was added to the blank group.

[0070] (3) After incubating the cells from each group treated in step (2) in an incubator for 24 hours, the cells were collected into centrifuge tubes, washed twice with 1 mL PBS, and cultured in serum-free medium containing 1 μM adenosine for 24 hours. Then, 0.5 μM xanthine oxidase (XOD) was added and cultured for 1 hour. The supernatant was transferred to a 96-well plate and its absorbance at 295 nm was measured using a microplate reader. The experiment was repeated three times. Uric acid content % = OD experimental group / OD control group × 100%.

[0071] The experimental results are shown in Table 14.

[0072] Table 14 Inhibitory activity of compounds from Examples 1 to 6 on uric acid levels

[0073] Table 14 validates the actual uric acid-lowering effects of the compounds in a hyperuricemia model constructed in HK-2 cells. Data shows that all compounds effectively reduced uric acid levels in the cell model at concentrations ranging from 5 to 25 μM, with the effect being concentration-dependent. At 25 μM, the uric acid level was reduced to 53.21%–62.81% of the control, an effect comparable to that of the 25 μM positive control drug febuxostat (55.01%). This ultimately confirms at the cellular level that these compounds do indeed possess significant uric acid-lowering functions.

[0074] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. The application of dihydrochalcone compounds in any of the following: 1) preparation of anti-pigmentation drugs; 2) preparation of uric acid-lowering drugs; the structural formula of the dihydrochalcone compound is shown in Formula I: ； In Formula I, R1 is tert-butyl or hydrogen; R2 is ethyl, propyl, chlorine, fluorine, hydrogen or tert-butyl; R3 and R4 are hydroxyl or benzyloxy, respectively.

2. The application according to claim 1, characterized in that: The dihydrochalcone compound is selected from at least one of the following compounds: 。 3. The application according to claim 1, characterized in that: The method for preparing the dihydrochalcone compound includes the following steps: ； In step a, compound III and compound II undergo an aldol condensation reaction under base catalysis to prepare compound IV; Step b: Prepare a solution of compound IV, introduce hydrogen gas into it, and catalytically hydrogenate to obtain compound I.

4. The application according to claim 3, characterized in that: The molar ratio of compound III to compound II is 1:1-1.2, and the base is sodium hydroxide or potassium hydroxide, with a molar ratio of base to compound III of 2-6:

1.

5. The application according to claim 3, characterized in that: Step a also includes the steps of extraction, vacuum distillation and purification of the reaction solution. The extraction method is as follows: first extract with ethyl acetate at least twice, collect the organic phase, and then wash the organic phase with saturated brine.

6. The application according to claim 3, characterized in that: The reaction temperature in step a is 75-85℃, and the reaction time is 2-4h.

7. The application according to claim 3, characterized in that: The reaction temperature in step b is 25-35℃, and the reaction time is 1-2 hours.

8. The application according to claim 3, characterized in that: The catalyst used in step b is palladium hydroxide / carbon.

9. The application according to claim 3, characterized in that: Step b also includes the step of vacuum distillation and purification of the reaction solution. The purification method is silica gel column chromatography, and the eluent is a mixture of petroleum ether and ethyl acetate in a volume ratio of 25-35:

1.

10. A pharmaceutical composition for treating skin pigmentation or lowering uric acid, characterized in that: It includes dihydrochalcone compounds and excipients in any of the applications described in claims 1-9.

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