Preparation process of curcumin ester derivative
By modifying curcumin with borneol, curcumin borneol succinate was prepared, which solved the problems of insufficient antioxidant capacity of curcumin and complex preparation process, and realized the production of antioxidants with high efficiency and low cost, which is suitable for oral drugs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 于慧敏
- Filing Date
- 2023-02-21
- Publication Date
- 2026-05-12
AI Technical Summary
There is room for improvement in the antioxidant capacity of existing curcumin, and the preparation process is complicated, costly, and difficult to industrialize.
Borneol was used to esterify curcumin to generate borneol ester by reacting succinic anhydride with borneol. Then, borneol ester was reacted with curcumin, and curcumin borneol ester was obtained by washing, drying, rotary evaporation, vacuum drying and silica gel column separation. This simplified the preparation process and improved the antioxidant capacity.
It significantly improves the antioxidant capacity of curcumin, reduces preparation costs, simplifies the process, facilitates industrial production, and has good biodegradability, making it suitable for oral medication.
Smart Images
Figure CN116283569B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical synthesis and improving the antioxidant properties of natural products, and mainly to a preparation process of curcumin esterification derivatives, providing curcumin esterification product—curcumin borneol ester, which improves the antioxidant capacity of curcumin. Background Technology
[0002] Curcumin was first isolated from turmeric in 1870 as a low molecular weight polyphenolic compound. It is an orange-yellow crystalline powder with a slightly bitter taste and is insoluble in water. With in-depth research on curcumin, it has been found to possess a wide range of pharmacological activities, including anti-inflammatory, antioxidant, lipid-regulating, antiviral, anti-infective, antitumor, anticoagulant, anti-liver fibrosis, and anti-atherosclerotic effects, with low toxicity and few adverse reactions. Given that modern medical research has found that the occurrence of many human diseases is related to the formation of free radicals and the involvement of inflammatory responses, the antioxidant and anti-inflammatory effects of curcumin have attracted widespread attention from scholars both domestically and internationally.
[0003] Borneol, also known as camphor or borneol, is obtained by steam distillation and recrystallization of the stems and leaves of *Asteraceae* or *Camellia sinensis* (a plant in the Lauraceae family). Its chemical composition is 2-borneol, and its chemical formula is C6H2O. 10 H 18 O. It can also be obtained from turpentine oil through a series of chemical processes. It can be used to clear the orifices, disperse stagnant heat, remove corneal opacity and improve vision, reduce swelling and relieve pain, clear heat and detoxify, and treat breast lumps, stroke with lockjaw, fever with delirium, epilepsy with phlegm, deafness due to qi stagnation, sore throat, canker sores, otitis media, carbuncles, hemorrhoids, corneal opacity, pinworm infection, etc. Summary of the Invention
[0004] Based on the above facts, this invention selects borneol to modify the structure of curcumin, significantly improving its antioxidant capacity while maintaining its original activity. Furthermore, the esterified derivatives of curcumin were comprehensively characterized. This process has the advantages of simple operation, short preparation cycle, low cost, easy scaling up, and easy industrialization.
[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:
[0006] This invention provides a process for preparing curcumin esterified derivatives, comprising the following steps:
[0007]
[0008] (1) Dissolve succinic anhydride and a certain amount of catalyst in a solvent and stir and reflux at a certain temperature.
[0009] (2) Dissolve a certain amount of borneol in a solvent and add it dropwise to the reaction solution in step (1), and let it react for a period of time.
[0010] (3) Wash the reaction solution from step (2) with washing solution until it is neutral.
[0011] (4) Add a desiccant to the reaction solution of step (3) and dry it. Then, rotary evaporate and vacuum dry to obtain borneol succinate.
[0012] (5) Dissolve curcumin and a certain amount of catalyst in a solvent and stir and reflux at a certain temperature.
[0013] (6) Dissolve a certain amount of borneol succinate obtained in step (4) in a solvent and add it dropwise to the reaction solution in step (5), and react for a period of time.
[0014] (7) Wash the reaction solution from step (6) with washing solution until it is neutral.
[0015] (8) The reaction solution from step (7) was dried with a desiccant, and then rotary evaporated and vacuum dried to obtain the crude product of curcumin borneol succinate.
[0016] (9) The crude product from step (8) was separated by silica gel column chromatography to obtain pure curcumin borneol succinate.
[0017] Preferably, the molar ratio of borneol to succinic anhydride in steps (1) and (2) is 1:0.1 to 1:3.
[0018] Preferably, the reaction solvent in steps (1) and (2) is dichloromethane.
[0019] Preferably, the catalyst in step (1) is 4-dimethylaminopyridine (DMAP) and triethylamine. The feeding ratio is based on the amount of succinic anhydride added, and the molar ratio is: succinic anhydride:DMAP:triethylamine = 1:0.1:0.1 to 1:3:3.
[0020] Preferably, the reaction temperature of borneol and succinic anhydride in steps (1) and (2) is 25-60 °C, and the reaction time is 12-48 h.
[0021] Preferably, the washing solutions in steps (3) and (4) are 0.1 mol / mL dilute hydrochloric acid and pure water, respectively. The drying agent is anhydrous sodium sulfate.
[0022] Preferably, the molar ratio of borneol to curcumin in steps (5) and (6) is 1:0.1 to 1:3.
[0023] Preferably, the reaction solvent in steps (5) and (6) is dichloromethane.
[0024] Preferably, the catalyst in step (5) is 4-dimethylaminopyridine (DMAP) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), and the feeding ratio is based on the amount of curcumin added, with a molar ratio of curcumin:DMAP:EDC = 1:0.1:0.1 to 1:3:3.
[0025] Preferably, the reaction temperature of borneol and curcumin in steps (5) and (6) is 25-60 °C, and the reaction time is 12-48 h.
[0026] Preferably, the washing solutions in steps (7) and (8) are saturated sodium bicarbonate solution and saturated sodium chloride solution, respectively. The drying agent is anhydrous sodium sulfate.
[0027] Preferably, the silica gel used in step (9) is 100-500 mesh, and the mobile phase is petroleum ether: ethyl acetate = 1:2-2:1.
[0028] The obtained borneol succinate infrared spectrum at 1744 cm⁻¹ -1 and 2900 cm -1 There is a characteristic peak at this location.
[0029] The obtained borneol succinate 1 Characteristic peaks are observed at 2.23 ppm and 4.8 ppm in the H NMR spectrum.
[0030] The obtained curcumin borneol ester infrared spectrum at 1250 cm⁻¹ -1 and 1730 cm -1 There is a characteristic peak at this location.
[0031] The obtained curcumin borneol ester 1 Characteristic peaks are observed at 3.8 ppm and 6.7 ppm in the H NMR spectrum.
[0032] This invention provides a process for preparing curcumin esterified derivatives, comprising the following steps: dissolving succinic anhydride and a certain amount of catalyst in a solvent, stirring and refluxing at a certain temperature; dissolving a certain amount of borneol in a solvent and adding it dropwise to the succinic anhydride reaction solution; after reacting for a period of time, washing the reaction solution sequentially with washing solution until neutral; adding a desiccant to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain borneol succinate; dissolving curcumin and a certain amount of catalyst in a solvent, stirring and refluxing at a certain temperature; dissolving a certain amount of borneol succinate in a solvent and adding it dropwise to the curcumin reaction solution; after reacting for a period of time, washing the reaction solution sequentially with washing solution until neutral; adding a desiccant to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain crude curcumin borneol succinate; and separating the crude product by silica gel column chromatography to obtain pure curcumin borneol succinate.
[0033] Infrared spectroscopy, thermogravimetric analysis, differential thermal scanning spectroscopy, 1 Characterization by 1H nuclear magnetic resonance spectroscopy and other methods revealed that the infrared spectrum of borneol succinate at 1744 cm⁻¹... -1 and 2900 cm -1 There is a characteristic peak at this location. 1 The H NMR spectrum shows characteristic peaks at 2.23 ppm and 4.8 ppm, indicating a change in thermodynamic properties. The obtained curcumin-borneol infrared spectrum shows a peak at 1250 cm⁻¹. -1 and 1730 cm -1 There is a characteristic peak at this location. 1 Characteristic peaks were observed at 3.8 ppm and 6.7 ppm in the 1H NMR spectrum, indicating a change in thermodynamic properties. This confirms the successful preparation of curcumin borneol ester. The IC50 value for DPPH scavenging by curcumin borneol ester was determined by DPPH and ABTS radical scavenging assays. 50 The value is 2.86 × 10 -3 mg / mL, lower than the 4.22×10 mg / mL of curcumin technical grade. -3 mg / mL. Curcumin-borneol scavenging IC50 of ABTS 50 The value is 1.14 × 10 -2 mg / mL, significantly lower than the 1.26 × 10 mg / mL of curcumin technical grade. -1 The concentration of mg / mL demonstrates a significant improvement in the antioxidant capacity of curcumin-borneol succinate. This invention utilizes borneol to modify the curcumin structure, resulting in good biodegradability, high biocompatibility, and facilitated intestinal absorption, making it suitable for oral medication preparation. The solvents used in this process are all non-toxic or low-toxicity, environmentally friendly, inexpensive, and the process is simple and easily scaled up for industrial production. Data from the examples show that the yield of borneol succinate in this invention is as high as 83.6%, the yield of curcumin-borneol succinate is 30.15%, and the purity is 95.27%. Attached Figure Description
[0034] Figure 1 Infrared spectroscopy images of curcumin technical (a), borneol succinate (b), and curcumin borneol succinate (c) prepared according to the present invention;
[0035] Figure 2 Thermogravimetric analysis (TGA) results for curcumin technical and borneol succinate and curcumin borneol succinate prepared according to this invention.
[0036] Figure 3 Differential thermal scanning chromatograms of curcumin technical and borneol succinate and curcumin borneol succinate prepared in this invention.
[0037] Figure 4 X-ray diffraction patterns of curcumin technical and borneol succinate and curcumin borneol succinate prepared in this invention;
[0038] Figure 5 The present invention comprises curcumin technical and borneol ester and curcumin borneol ester prepared by the present invention. 1 H-NMR detection map; Detailed Implementation
[0039] This invention provides a curcumin esterified derivative and its preparation process, comprising the following steps:
[0040] Succinic anhydride and a certain amount of catalyst are dissolved in a solvent and stirred and refluxed at a certain temperature.
[0041] A certain amount of borneol is dissolved in a solvent and added dropwise to the reaction solution in step (1), and the reaction is allowed to proceed for a period of time.
[0042] Wash the reaction solution from step (2) with washing solution until it is neutral;
[0043] Add a desiccant to the reaction solution in step (3) and dry it. Then, evaporate it by rotary evaporation and vacuum drying to obtain borneol succinate.
[0044] Curcumin and a certain amount of catalyst are dissolved in a solvent and stirred and refluxed at a certain temperature.
[0045] A certain amount of borneol succinate obtained in step (4) is dissolved in a solvent and added dropwise to the reaction solution in step (5), and the reaction is carried out for a period of time;
[0046] Wash the reaction solution from step (6) with washing solution until it is neutral;
[0047] The reaction solution from step (7) was dried with a desiccant, and then rotary evaporated and vacuum dried to obtain the crude product of curcumin borneol succinate.
[0048] The crude product from step (8) was separated by silica gel column chromatography to obtain pure curcumin borneol succinate.
[0049] Succinic anhydride and a certain amount of catalyst were dissolved in a solvent and stirred under reflux at a certain temperature. A certain amount of borneol was dissolved in a solvent and added dropwise to the reaction solution of step (1), and the reaction was allowed to proceed for a period of time.
[0050] In this invention, the molar ratio of borneol to succinic anhydride in steps (1) and (2) is 1:0.1 to 1:3, more preferably 1:1 to 1:2, and most preferably 1:1. The reaction solvent is dichloromethane. The catalysts are 4-dimethylaminopyridine (DMAP) and triethylamine, with the feeding ratio based on the amount of succinic anhydride added, and the molar ratio is: succinic anhydride:DMAP:triethylamine = 1:0.1:0.1 to 1:3:3, more preferably 1:1 to 1:2, and most preferably 1:1.2. The reaction temperature is 25 to 60 °C, more preferably 30 to 50 °C, and most preferably 40 °C. The reaction time is 12 to 48 h, more preferably 18 to 30 h, and most preferably 24 h.
[0051] The reaction solution from step (2) was washed sequentially with washing solution until neutral. A desiccant was added to the reaction solution from step (3) and dried by rotary evaporation and vacuum drying to obtain borneol succinate.
[0052] In this invention, the washing solutions in steps (3) and (4) are 0.1 mol / mL dilute hydrochloric acid and pure water, respectively. The drying agent is anhydrous sodium sulfate.
[0053] Curcumin and a certain amount of catalyst were dissolved in a solvent and stirred under reflux at a certain temperature. A certain amount of borneol obtained in step (4) was dissolved in a solvent and added dropwise to the reaction solution in step (5), and the reaction was allowed to proceed for a period of time.
[0054] In this invention, the molar ratio of borneol to curcumin in steps (5) and (6) is 1:0.1 to 1:3, more preferably 1:1 to 1:2, and most preferably 1:1.2. The reaction solvent is dichloromethane. The catalysts are 4-dimethylaminopyridine (DMAP) and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), with the molar ratio based on the amount of curcumin added: curcumin:DMAP:EDC = 1:0.1:0.1 to 1:3:3, more preferably 1:1 to 1:2, and most preferably 1:1.2. The reaction temperature is 25 to 60 °C, more preferably 40 to 50 °C, and most preferably 45 °C. The reaction time is 12 to 48 h, more preferably 18 to 30 h, and most preferably 24 h.
[0055] The reaction solution from step (6) was washed sequentially with washing solution until neutral. The reaction solution from step (7) was dried with a desiccant, and then rotary evaporated and vacuum dried to obtain the crude product of curcumin borneol succinate.
[0056] In this invention, the washing solutions in steps (7) and (8) are, respectively, saturated sodium bicarbonate solution and saturated sodium chloride solution. The drying agent is anhydrous sodium sulfate.
[0057] The crude product from step (8) was separated by silica gel column chromatography to obtain pure curcumin borneol succinate.
[0058] In this invention, the silica gel used in step (9) is 100-500 mesh, more preferably 200-400 mesh, and most preferably 300 mesh. The mobile phase is petroleum ether:ethyl acetate = 1:2-2:1, more preferably 1:1-2:1, and most preferably 3:2.
[0059] To further illustrate the present invention, the synthesis method of curcumin borneol ester provided by the present invention will be described in detail below with reference to examples, but these should not be construed as limiting the scope of protection of the present invention.
[0060] Example 1
[0061] Borneol and succinic anhydride (molar ratio 1:1) were weighed out. Succinic anhydride, DMAP, and triethylamine were dissolved in dichloromethane and refluxed at 25°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the succinic anhydride reaction solution. After reacting for 24 h, the reaction solution was washed successively with 0.1 mol / mL dilute hydrochloric acid and pure water until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain borneol succinate. Borneol and curcumin (molar ratio 1:0.5) were weighed out. Curcumin, DMAP, and EDC were dissolved in dichloromethane and refluxed at 25°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the curcumin reaction solution. After reacting for 8 h, the reaction solution was washed successively with saturated sodium bicarbonate solution and saturated sodium chloride solution until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain crude curcumin borneol succinate. The crude product was separated by a 300-mesh silica gel column with petroleum ether:ethyl acetate = 3:2 as the mobile phase to obtain pure curcumin borneol ester with a purity of 94.88% and a yield of 14.75%.
[0062] Example 2
[0063] Borneol and succinic anhydride (molar ratio 1:1) were weighed out. Succinic anhydride, DMAP, and triethylamine were dissolved in dichloromethane and refluxed at 25°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the succinic anhydride reaction solution. After reacting for 24 h, the reaction solution was washed successively with 0.1 mol / mL dilute hydrochloric acid and pure water until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain borneol succinate. Borneol and curcumin (molar ratio 1:1.2) were weighed out. Curcumin, DMAP, and EDC were dissolved in dichloromethane and refluxed at 45°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the curcumin reaction solution. After reacting for 24 h, the reaction solution was washed successively with saturated sodium bicarbonate solution and saturated sodium chloride solution until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain crude curcumin borneol succinate. The crude product was separated by a 300-mesh silica gel column with petroleum ether:ethyl acetate = 3:2 as the mobile phase to obtain pure curcumin borneol ester with a purity of 95.23% and a yield of 30.15%.
[0064] Example 3
[0065] Borneol and succinic anhydride (molar ratio 1:1) were weighed out in a specific molar ratio. Succinic anhydride, DMAP, and triethylamine were dissolved in dichloromethane and refluxed at 25°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the succinic anhydride reaction solution. After reacting for 24 h, the reaction solution was washed successively with 0.1 mol / mL dilute hydrochloric acid and pure water until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain borneol succinate. Borneol and curcumin (molar ratio 1:1) were weighed out in a specific molar ratio. Curcumin, DMAP, and EDC were dissolved in dichloromethane and refluxed at 35°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the curcumin reaction solution. After reacting for 24 h, the reaction solution was washed successively with saturated sodium bicarbonate solution and saturated sodium chloride solution until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain crude curcumin borneol succinate. The crude product was separated by a 300-mesh silica gel column with petroleum ether:ethyl acetate = 3:2 as the mobile phase to obtain pure curcumin borneol ester with a purity of 95.27% and a yield of 24.37%.
[0066] Example 4
[0067] Borneol and succinic anhydride (molar ratio 1:1) were weighed out. Succinic anhydride, DMAP, and triethylamine were dissolved in dichloromethane and refluxed at 25°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the succinic anhydride reaction solution. After reacting for 24 h, the reaction solution was washed successively with 0.1 mol / mL dilute hydrochloric acid and pure water until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain borneol succinate. Borneol and curcumin (molar ratio 1:1.2) were weighed out. Curcumin, DMAP, and EDC were dissolved in dichloromethane and refluxed at 45°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the curcumin reaction solution. After reacting for 12 h, the reaction solution was washed successively with saturated sodium bicarbonate solution and saturated sodium chloride solution until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain crude curcumin borneol succinate. The crude product was separated by a 300-mesh silica gel column with petroleum ether:ethyl acetate = 3:2 as the mobile phase to obtain pure curcumin borneol ester with a purity of 95.12% and a yield of 21.76%.
[0068] Example 5
[0069] Borneol and succinic anhydride (molar ratio 1:1) were weighed out at a specific molar ratio. Succinic anhydride, DMAP, and triethylamine were dissolved in dichloromethane and refluxed at 25°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the succinic anhydride reaction solution. After reacting for 24 h, the reaction solution was washed successively with 0.1 mol / mL dilute hydrochloric acid and pure water until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain borneol succinate. Borneol and curcumin (molar ratio 1:1) were weighed out at a specific molar ratio. Curcumin, DMAP, and EDC were dissolved in dichloromethane and refluxed at 35°C with stirring. Borneol was dissolved in dichloromethane and added dropwise to the curcumin reaction solution. After reacting for 48 h, the reaction solution was washed successively with saturated sodium bicarbonate solution and saturated sodium chloride solution until neutral. Anhydrous sodium sulfate was added to the reaction solution for drying, followed by rotary evaporation and vacuum drying to obtain crude curcumin borneol succinate. The crude product was separated by a 300-mesh silica gel column with petroleum ether:ethyl acetate = 3:2 as the mobile phase to obtain pure curcumin borneol ester with a purity of 94.76% and a yield of 28.62%.
[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A preparation process for a curcumin esterified derivative, characterized in that, Includes the following steps: (1) Succinic anhydride and a certain amount of catalyst 4-dimethylaminopyridine DMAP and triethylamine are dissolved in a solvent and stirred and refluxed at a certain temperature. The feeding ratio is based on the amount of succinic anhydride added, and the molar ratio is: succinic anhydride:DMAP:triethylamine = 1:0.1:0.1~1:3:3; (2) Dissolve a certain amount of borneol in a solvent and add it dropwise to the reaction solution of step (1), and let it react for a period of time; (3) Wash the reaction solution from step (2) with washing solution until it is neutral; (4) Add a desiccant to the reaction solution of step (3) and dry it by rotary evaporation and vacuum drying to obtain borneol succinate; (5) Dissolve curcumin with a certain amount of catalyst 4-dimethylaminopyridine DMAP and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride EDC in a solvent, stir and reflux at a certain temperature, and the feeding ratio is based on the amount of curcumin added, with a molar ratio of curcumin:DMAP:EDC=1:0.1:0.1~1:3:3; (6) Dissolve a certain amount of borneol obtained in step (4) in a solvent and add it dropwise to the reaction solution in step (5), and react at 35-60℃ for 12-48 h, wherein the molar ratio of borneol to curcumin is 1:1-1:
3. (7) Wash the reaction solution from step (6) with washing solution until it is neutral; (8) The reaction solution from step (7) was dried with a desiccant, and then rotary evaporated and vacuum dried to obtain the crude product of curcumin borneol succinate; (9) The crude product from step (8) was separated by silica gel column chromatography to obtain pure curcumin borneol succinate.
2. The preparation process of a curcumin esterified derivative according to claim 1, characterized in that, The molar ratio of borneol to succinic anhydride in steps (1) and (2) is 1:0.1 to 1:
3.
3. The preparation process of a curcumin esterified derivative according to claim 1, characterized in that, The reaction solvent in steps (1) and (2) is dichloromethane.
4. The preparation process of a curcumin esterified derivative according to claim 1, characterized in that, The reaction temperature of borneol and succinic anhydride in steps (1) and (2) is 25-60 °C, and the reaction time is 12-48 h.
5. The preparation process of a curcumin esterified derivative according to claim 1, characterized in that, The reaction solvent in steps (5) and (6) is dichloromethane.
6. The preparation process of a curcumin esterified derivative according to claim 1, characterized in that, The silica gel used in step (9) is 100-500 mesh, and the mobile phase is petroleum ether: ethyl acetate = 1:2-2:
1.
7. The preparation process of a curcumin esterified derivative according to claim 1, characterized in that, The obtained infrared spectrum of borneol succinate at 1744 cm⁻¹ -1 and 2900 cm -1 There is a characteristic peak at this location.
8. The preparation process of a curcumin esterified derivative according to claim 1, characterized in that, The obtained borneol succinate 1 Characteristic peaks are observed at 2.23 ppm and 4.8 ppm in the H NMR spectrum.
9. The preparation process of a curcumin esterified derivative according to claim 2, characterized in that, The obtained curcumin borneol ester infrared spectrum at 1250 cm⁻¹ -1 and 1730 cm -1 There is a characteristic peak at this location.
10. The preparation process of a curcumin esterified derivative according to claim 2, characterized in that, The obtained curcumin borneol succinate 1 Characteristic peaks are observed at 3.8 ppm and 6.7 ppm in the H NMR spectrum.