Preparation method and application of royal jelly acid

Abstract

The invention discloses a preparation method and application of royal jelly acid, belongs to the technical field of chemical synthesis, and solves the problem that preparation of royal jelly acid in the prior art cannot simultaneously have simple steps and mild conditions. The method comprises the following steps: carrying out esterification reaction on 9-bromine-1-nonene and acrylic acid under the action of an organic solvent and alkali to obtain acrylic acid-8-nonene-1-yl ester of which the structural formula is shown as a formula I; under the action of a catalyst, acrylic acid-8-nonene-1-yl ester is subjected to an olefin metathesis reaction to obtain a compound with a structural formula as shown in a formula II; and carrying out hydrolysis reaction under an alkaline condition, and acidifying to obtain the royal jelly acid. According to the method provided by the invention, the raw materials are wide in source and relatively low in price, the synthesis efficiency and the product yield are improved, the equipment cost and the production risk are reduced, and implementation of industrial production is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical synthesis, and more specifically to a preparation method and application of royal jelly acid. Background Art

[0002] Royal jelly acid, namely 10-hydroxy-2-decenoic acid, is the characteristic active ingredient in royal jelly. Its content in royal jelly is relatively stable, accounting for about 1.4% to 2.4% of the dry matter of royal jelly.

[0003] Royal jelly acid has many important physiological functions. It has significant antibacterial and anti-inflammatory properties, can effectively inhibit the growth and reproduction of a variety of bacteria and fungi, and plays a positive role in maintaining the health of the body. In terms of immune regulation, it can enhance the body's immunity and help the body resist the invasion of external pathogens. At the same time, royal jelly acid also plays an important role in the anti-oxidation process, helping to remove free radicals in the body and slow down cell oxidative damage, which is of great significance for delaying aging and preventing chronic diseases.

[0004] Currently, there are many chemical synthesis methods for royal jelly acid, including Grignard reagent method, Witting-Horner reagent method, ozonation method, bromination method, Knoevenagel condensation method, etc. However, these synthesis routes are either cumbersome steps or have high raw material costs and harsh reaction conditions, and are not suitable for large-scale production. Summary of the invention

[0005] The present invention provides a preparation method and application of royal jelly acid, which are used to solve the problem that the preparation of royal jelly acid in the prior art cannot have both simple steps and mild conditions.

[0006] In a first aspect, the present invention provides a method for preparing royal jelly acid, comprising the following steps: 9-bromo-1-nonene and acrylic acid undergo an esterification reaction under the action of an organic solvent and a base to obtain 8-nonen-1-yl acrylate, the structural formula of which is shown in Formula I; an olefin metathesis reaction occurs under the action of a catalyst to obtain an intermediate product with a structural formula shown in Formula II; a hydrolysis reaction occurs under alkaline conditions, followed by acidification to obtain the royal jelly acid;

[0007]

[0008] As a possible implementation manner, the organic solvent is any one of dichloromethane, tetrahydrofuran, toluene, 1,4-dioxane, and N,N-dimethylformamide; and / or the base is any one of potassium carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, triethylamine, pyridine, N-methylmorpholine, and DBU; and / or the catalyst is any one of Grubbs first-generation catalyst, Grubbs second-generation catalyst, and Hoveyda-Grubbs catalyst.

[0009] As a possible implementation, the 9-bromo-1-nonene, the acrylic acid, the organic solvent and the base are mixed and heated to 60-70 °C, and the reaction is carried out for 4-6 h. After the reaction is complete, it is cooled to room temperature, and liquid separation operation is carried out. The organic phase is retained, and the 8-nonen-1-yl acrylate is obtained after purification; the dosage of the catalyst is 0.5%-1% of the mass of the 8-nonen-1-yl acrylate; the acidification is to adjust the pH of the reaction system to 3-4.

[0010] As a possible implementation, the yield of this preparation method is greater than 85%.

[0011] In a second aspect, the present invention provides royal jelly acid prepared by the preparation method according to any one of the possible implementations in the first aspect, and the purity of the royal jelly acid is greater than 99%.

[0012] In a third aspect, the present invention provides the use of the royal jelly acid prepared by the preparation method according to any one of the possible implementations in the first aspect or the royal jelly acid according to any one of the possible implementations in the second aspect in the preparation of antioxidant preparations.

[0013] As a possible implementation, the royal jelly acid is used to scavenge free radicals.

[0014] As a possible implementation, the antioxidant preparation is a skin care product or a cosmetic.

[0015] In the preparation method provided by the present invention, the bromine atom in 9-bromo-1-nonene undergoes a nucleophilic substitution reaction with acrylic acid under the action of a base to generate 8-nonen-1-yl acrylate. The presence of the base promotes the progress of the reaction. By providing an alkaline environment, the activity of the nucleophile is enhanced. The Grubbs second-generation catalyst coordinates with the carbon-carbon double bond in compound I to form a metal heterocyclic intermediate. The intermediate undergoes a series of rearrangement, cleavage and recombination processes to achieve olefin metathesis and obtain compound II. Under alkaline conditions, the ester group in compound II undergoes a hydrolysis reaction to generate carboxylate and alcohol. After adding hydrochloric acid for acidification, the carboxylate is converted into royal jelly acid, and by controlling the pH value, the royal jelly acid is precipitated in the free form.

[0016] In the preparation method provided by the present invention, the starting material 9-bromo-1-nonene has a wide source, relatively low price, and is easily obtainable in the market, which reduces the production cost and provides a solid raw material basis for large-scale industrial production. The target product, royal jelly acid, can be obtained only through three steps of reactions: esterification, olefin metathesis, and hydrolysis. Compared with the traditional multi-step synthesis route, the intermediate links are reduced, which not only shortens the reaction time but also reduces the probability of side reactions, improving the synthesis efficiency and product yield. The reaction temperature for each step is moderate and carried out within conventional temperature ranges such as 60-70 °C and 40-50 °C, requiring no special high-temperature and high-pressure equipment for the reaction, which reduces the equipment cost and production risk and is conducive to the implementation of industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0018] Figure 1 1H NMR spectrum of pure royal jelly acid provided by an embodiment of the present invention.

[0019] Figure 2 HPLC spectrum of pure royal jelly acid provided by an embodiment of the present invention.

[0020] Figure 3 Experimental results of the free radical scavenging rate of vitamin C provided by an embodiment of the present invention.

[0021] Figure 4 Experimental results of the free radical scavenging rate of royal jelly acid provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0023] The technical solutions of the present invention will be further elaborated below with reference to specific embodiments.

[0024] Example 1

[0025] This example provides an experiment for the preparation of royal jelly acid.

[0026] Esterification reaction: 100.0 g (0.487 mol, 1.0 eq.) of 9-bromo-1-nonene, 200 mL of tetrahydrofuran, 42.2 g (0.585 mol, 1.2 eq.) of acrylic acid and 101.1 g (0.731 mol, 1.5 eq.) of potassium carbonate were successively added to a 500 mL three-necked flask. Heating and stirring were started, and the temperature was raised to 65 °C. The reaction was carried out for 6 h. After monitoring by TLC that the raw materials had been completely converted, it was cooled to room temperature. 200 mL of ethyl acetate and 200 mL of water were added to the reaction system, and after stirring and salting out in the system, it was transferred to a separatory funnel for liquid separation. The organic phase was washed 3 times with 100 mL of saturated brine, and after evaporation to dryness, 89.0 g of white solid 8-nonen-1-yl acrylate was obtained, with a yield of 93.0%.

[0027] Olefin metathesis reaction: 80.0 g of the prepared 8-nonen-1-yl acrylate was dissolved in 800 mL of dichloromethane. After deoxygenation by nitrogen bubbling, 0.4 g of Grubbs second-generation catalyst was added to the solution under nitrogen protection, and the temperature was raised to 40 °C for reaction for 4 h. After the reaction was completed, most of the solvent was removed by distillation under reduced pressure, and it was added to 240 mL of a mixed solvent (dichloromethane:n-hexane = 2:1). It was cooled to 5 °C for recrystallization, and white solid was precipitated. After filtration and drying, 61.8 g of compound (Ⅱ) was obtained, with a yield of 90.1%.

[0028] Hydrolysis and acidification reaction: 60.0 g of the prepared compound (Ⅱ), 180 mL of ethanol, and 120 mL of 20% sodium hydroxide aqueous solution were added to a 500 mL single-necked flask, and the temperature was raised to 75 °C for reaction for 2 h. After the reaction was completed, ethanol was removed by distillation under reduced pressure. Concentrated hydrochloric acid was added dropwise to the residual aqueous solution to adjust the pH of the solution to 3 - 4. Then, 300 mL of ethyl acetate was added for extraction 3 times. After liquid separation, the ethyl acetate layer was evaporated to dryness to obtain 68.0 g of crude 10-hydroxy-2-decenoic acid. The crude product was recrystallized in 180 mL of a mixed solvent (petroleum ether:ethyl acetate = 2:1) by cooling to 0 °C, and white solid was precipitated. After filtration and drying, 62.5 g of pure 10-hydroxy-2-decenoic acid was obtained, with a yield of 94.1%. After detection by HPLC (high performance liquid chromatography), the purity was 99.0%, and the spectrum was as Figure 2 shown. Its 1H spectrum was as Figure 1 shown.

[0029] 1 HNMR(CDCl3,δ(ppm),TMS): δ1.33 - 1.58(m,10H), 2.21(q,2H), 3.65(t,2H), 5.81(d,1H), 6.34 - 6.82(s,br,2H), 7.06(dt,1H)

[0030] Example 2

[0031] This example provides an experimental preparation of 10-hydroxy-2-decenoic acid.

[0032] In the esterification reaction, 101.1 g (0.731 mol, 1.5 eq.) of potassium carbonate was replaced with 41.1 g (0.731 mol, 1.5 eq.) of potassium hydroxide, and the remaining operations were the same as in Example 1; 86.8 g of 8-nonen-1-yl acrylate was obtained, with a yield of 92.1%. The subsequent operations were the same as in Example 1 to prepare pure 10-hydroxy-2-decenoic acid.

[0033] Example 3

[0034] This example provides an experiment for the preparation of 10-hydroxy-2-decenoic acid.

[0035] In the esterification reaction, 101.1 g (0.731 mol, 1.5 eq.) of potassium carbonate was replaced with 29.2 g (0.731 mol, 1.5 eq.) of sodium hydroxide, and the remaining operations were the same as in Example 1; 85.5 g of 8-nonen-1-yl acrylate was obtained, with a yield of 89.4%. The subsequent operations were the same as in Example 1 to prepare pure 10-hydroxy-2-decenoic acid.

[0036] Example 4

[0037] This example provides an experiment for the preparation of 10-hydroxy-2-decenoic acid.

[0038] In the esterification reaction, 200 mL of tetrahydrofuran was replaced with 200 mL of 1,4-dioxane. The remaining raw materials were the same as in Example 1. All the raw materials were added into a 500 mL three-necked flask, heated and stirred, and the temperature was raised to 80 °C and reacted for 4 h. The remaining operations were the same as in Example 1; 89.6 g of 8-nonen-1-yl acrylate was obtained, with a yield of 93.6%. The subsequent operations were the same as in Example 1 to prepare pure 10-hydroxy-2-decenoic acid.

[0039] Example 5

[0040] This example provides an experiment for the preparation of 10-hydroxy-2-decenoic acid.

[0041] In the esterification reaction, 200 mL of tetrahydrofuran was replaced with 200 mL of toluene. The remaining raw materials were the same as in Example 1. All the raw materials were added into a 500 mL three-necked flask, heated and stirred, and the temperature was raised to 80 °C and reacted for 4 h. The remaining operations were the same as in Example 1; 87.5 g of 8-nonen-1-yl acrylate was obtained, with a yield of 91.4%. The subsequent operations were the same as in Example 1 to prepare pure 10-hydroxy-2-decenoic acid.

[0042] Example 6

[0043] This example provides an experiment for the preparation of 10-hydroxy-2-decenoic acid.

[0044] In the olefin metathesis reaction, 0.4 g of the second-generation Grubbs catalyst was replaced with 0.4 g of the first-generation Grubbs catalyst, and the temperature was raised to 40 °C and reacted for 3 h. The remaining operations were the same as those in Example 1; 59.3 g of compound (II) was obtained, and the yield was 86.5%. The subsequent operations were the same as those in Example 1 to prepare pure royal jelly acid.

[0045] Example 7

[0046] This example provides an experiment for the preparation of royal jelly acid.

[0047] In the olefin metathesis reaction, 0.4 g of the second-generation Grubbs catalyst was replaced with 0.4 g of the first-generation Hoveyda-Grubbs catalyst, and the temperature was raised to 40 °C and reacted for 3 h. The remaining operations were the same as those in Example 1; 61.3 g of compound (II) was obtained, and the yield was 89.4%. The subsequent operations were the same as those in Example 1 to prepare pure royal jelly acid.

[0048] Example 8

[0049] This example provides an experiment for the preparation of royal jelly acid.

[0050] In the olefin metathesis reaction, 0.4 g of the second-generation Grubbs catalyst was replaced with 0.4 g of the second-generation Hoveyda-Grubbs catalyst, and the temperature was raised to 40 °C and reacted for 3 h. The remaining operations were the same as those in Example 1; 62.8 g of compound (II) was obtained, and the yield was 91.6%. The subsequent operations were the same as those in Example 1 to prepare pure royal jelly acid.

[0051] Example 9

[0052] This example provides an experiment for the preparation of royal jelly acid.

[0053] In the hydrolysis acidification reaction, the reaction system was heated to 60 °C and reacted for 6 h. The remaining operations were the same as those in Example 1; 61.9 g of pure royal jelly acid was obtained, and the yield was 93.2%. After detection by HPLC (high performance liquid chromatography), the purity was 98.9%.

[0054] Example 10

[0055] This example provides an experiment for the preparation of royal jelly acid.

[0056] In the hydrolysis acidification reaction, 180 mL of ethanol was replaced with 180 mL of isopropanol, and the other raw materials were the same as those in Example 1. The reaction system was heated to 80 °C and reacted for 2 h. The remaining operations were the same as those in Example 1; 60.5 g of pure royal jelly acid was obtained, and the yield was 91.1%. After detection by HPLC (high performance liquid chromatography), the purity was 99.1%.

[0057] Example 11

[0058] This embodiment provides an application experiment of 10 - hydroxy - 2 - decenoic acid (10 - HDA).

[0059] Dissolve the 10 - HDA prepared in Example 1 in pentanediol to obtain sample solutions with final concentrations of 640 μmol / mL, 320 μmol / mL, 160 μmol / mL, 80 μmol / mL, 40 μmol / mL, 20 μmol / mL, 10 μmol / mL, and 5 μmol / mL respectively. Mix 10 μL of each sample solution with 190 μL of 0.25 mmol / L ABTS working solution uniformly and shake well to obtain the ABTS working solution of the sample; mix 10 μL of each sample solution with 190 μL of pentanediol uniformly and shake well to obtain the pentanediol solution of the sample. Incubate all the ABTS working solutions of the samples and all the pentanediol solutions of the samples at room temperature for 6 minutes, and measure the absorbance at 405 nm. The absorbance of the ABTS working solution of the sample is denoted as A1, the absorbance of the pentanediol solution of the sample is denoted as A2, and the absorbance of the blank ABTS working solution and the blank pentanediol is denoted as A3. Calculate the ABTS radical scavenging rate according to the formula ABTS scavenging rate = [1 - (A1 - A2) / A3]×100%. Among them, for the positive control group: load vitamin C at concentrations of 3200 nmol / mL, 1600 nmol / mL, 800 nmol / mL, 400 nmol / mL, 200 nmol / mL, 100 nmol / mL, 50 nmol / mL, and 25 nmol / mL. The results are as shown in Figure 3 、 Figure 4 and Table 1.

[0060] Table 1 Radical Scavenging Rate of 10 - HDA

[0061]

[0062] It can be seen from Figure 3 that the IC 50 of the positive control VC is 0.251 μmol / mL, within the range of 0.23 - 0.40 μmol / mL. Therefore, it is considered that this test system is effective. It can be seen from Table 1 and Figure 4 that the IC 50 of the ABTS scavenging rate of 10 - HDA is 50.418 μmol / mL. The 10 - HDA prepared in the present invention has excellent antioxidant efficacy.

[0063] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications once they learn the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0064] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing 10-hydroxy-2-decenoic acid, characterized in that, It includes the following steps: 9-bromo-1-nonene and acrylic acid react under the action of an organic solvent and a base to undergo an esterification reaction to obtain 8-nonen-1-yl acrylate, and its structural formula is as shown in Formula I; Under the action of a catalyst, the 8-nonen-1-yl acrylate undergoes olefin metathesis reaction to obtain a compound with a structural formula as shown in Formula II; After undergoing a hydrolysis reaction under alkaline conditions, acidification is carried out to obtain the royal jelly acid; 2. The preparation method according to claim 1, wherein The organic solvent is any one of dichloromethane, tetrahydrofuran, toluene, 1,4-dioxane, N,N-dimethylformamide; And / or, the base is any one of potassium carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, triethylamine, pyridine, N-methylmorpholine, DBU; And / or, the catalyst is any one of Grubbs first-generation catalyst, Grubbs second-generation catalyst, and Hoveyda-Grubbs catalyst.

3. The preparation method according to claim 1, characterized in that, Mix the 9-bromo-1-nonene, the acrylic acid, the organic solvent, and the base, heat up to 60-70 °C, react for 4-6 h, after the reaction is complete, cool to room temperature, carry out a liquid separation operation, retain the organic phase, and obtain the 8-nonen-1-yl acrylate after purification; The dosage of the catalyst is 0.5%-1% of the mass of the 8-nonen-1-yl acrylate; The acidification is to adjust the pH of the reaction system to 3-4.

4. The preparation method according to claim 1, characterized in that, The yield of this preparation method is greater than 85%. The 10 - hydroxy - 2 - decenoic acid prepared by the preparation method according to any one of claims 1 to 4, characterized in that, The purity of the royal jelly acid is greater than 99%.

6. Use of the royal jelly acid prepared by the preparation method according to any one of claims 1-4 or the royal jelly acid according to claim 5 in the preparation of an antioxidant preparation.

7. The application according to claim 6, wherein The royal jelly acid is used for scavenging free radicals.

8. The application according to claim 6, wherein The antioxidant preparation is a skin care product or a cosmetic.

Images