Preparation method and application of royal jelly acid

Abstract

The application discloses a preparation method and application of royal jelly acid, and belongs to the technical field of chemical synthesis, and solves the problem that the preparation of royal jelly acid in the prior art cannot have simple steps and mild conditions. The method comprises the following steps: 9-bromo-1 nonene and acrylic acid are subjected to esterification reaction under the action of an organic solvent and an alkali, so that acrylic acid-8-nonene-1-yl ester is obtained, and the structural formula is shown as formula I; under the action of a catalyst, the acrylic acid-8-nonene-1-yl ester is subjected to olefin metathesis reaction, so that a compound with a structural formula shown as formula II is obtained; after hydrolysis reaction under alkaline conditions, acidification is performed, so that royal jelly acid is obtained. The method provided by the application has the advantages of wide raw material sources, relatively low price, improved synthesis efficiency and product yield, reduced equipment cost and production risk, and is beneficial to the implementation of industrialized production.

Description

TECHNICAL FIELD

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

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

[0003] Royal jelly acid has many important physiological functions. Its antibacterial and anti-inflammatory properties are remarkable, and it can effectively inhibit the growth and reproduction of various bacteria and fungi, playing an active 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 external pathogen invasion. At the same time, royal jelly acid also plays an important role in the process of antioxidant, helping to remove free radicals in the body and slow down cell oxidative damage, which is of great significance to delay aging and prevent 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 complicated in steps or have high raw material costs and harsh reaction conditions, which are not suitable for large-scale production. SUMMARY

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

[0006] In a first aspect, the present application provides a preparation method of royal jelly acid, comprising the following steps: 9-bromo-1-nonene and acrylic acid are subjected to esterification reaction under the action of an organic solvent and a base to obtain acrylic acid-8-nonene-1-yl ester, which has a structural formula as shown in Formula I; under the action of a catalyst, olefin metathesis reaction occurs to obtain an intermediate product having a structural formula as shown in Formula II; after hydrolysis reaction under alkaline conditions, acidification is performed 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 manner, the 9-bromo-1-nonene, the acrylic acid, the organic solvent and the base are mixed to be heated to 60-70 DEG C, and reacted for 4-6 hours, the reaction is completed, and the reaction is cooled to room temperature, and the organic phase is reserved after the liquid separation operation, and the acrylic acid-8-nonene-1-yl ester is obtained after purification; the amount of the catalyst is 0.5%-1% of the mass of the acrylic acid-8-nonene-1-yl ester; and the acidification is to adjust the pH of the reaction system to 3-4.

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

[0011] In a second aspect, the application provides royal jelly acid prepared by the preparation method in any possible implementation manner of the first aspect, and the purity of the royal jelly acid is greater than 99%.

[0012] In a third aspect, the application provides application of the royal jelly acid prepared by the preparation method in any possible implementation manner of the first aspect or the royal jelly acid in any possible implementation manner of the second aspect in preparation of an antioxidant preparation.

[0013] As a possible implementation manner, the royal jelly acid is used for scavenging free radicals.

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

[0015] The preparation method provided by the application is as follows: the bromine atom in 9-bromo-1-nonene reacts with acrylic acid under the action of a base to generate acrylic acid-8-nonene-1-yl ester. The presence of the base promotes the reaction, and the activity of the nucleophile is enhanced by providing an alkaline environment. The Grubbs second-generation catalyst is coordinated with the carbon-carbon double bond in compound I to form a metal heterocyclic intermediate, and the intermediate realizes olefin metathesis through a series of rearrangement, breaking and recombination processes to obtain compound II. Under alkaline conditions, the ester group in compound II is hydrolyzed to generate a carboxylate and an alcohol. After hydrochloric acid is added for acidification, the carboxylate is converted into royal jelly acid, and the royal jelly acid is precipitated in a free form by controlling the pH value.

[0016] The preparation method provided by the application has the advantages that the starting material 9-bromo-1-nonene is widely available and relatively low in price, and is easy to obtain on the market, thereby reducing the production cost and providing a solid raw material basis for large-scale industrial production. The target product royal jelly acid can be obtained through only three steps of esterification, olefin metathesis and hydrolysis, compared with the traditional multi-step synthesis route, the intermediate links are reduced, the reaction time is shortened, the probability of side reactions is reduced, the synthesis efficiency and product yield are improved. The reaction temperature of each step is moderate, which is in the conventional temperature range of 60-70 DEG C and 40-50 DEG C, and the reaction equipment requirement is not high, without the need for special high-temperature and high-pressure equipment, thereby reducing the equipment cost and production risk, and being conducive to the implementation of industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0018] Figure 1 The H spectrum of the royal jelly acid pure product provided by the embodiment of the present application.

[0019] Figure 2 The HPLC spectrum of the royal jelly acid pure product provided by the embodiment of the present application.

[0020] Figure 3 The free radical scavenging rate experimental results of vitamin C provided by the embodiment of the present application.

[0021] Figure 4 The free radical scavenging rate experimental results of royal jelly acid provided by the embodiment of the present application. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

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

[0024] Embodiment 1

[0025] The present embodiment provides a preparation experiment of royal jelly acid.

[0026] Esterification reaction: 100.0 g (0.487 mol, 1.0 eq.) of 9-bromo-l-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 sequentially added into a 500 mL three-necked flask, and heating and stirring were started, and the temperature was raised to 65°C, and the reaction was carried out for 6 hours. After the raw material was completely converted as monitored by TLC, the reaction system was cooled to room temperature. 200 mL of ethyl acetate and 200 mL of water were added into the reaction system, and stirring was carried out. After the salts in the system were dissolved, the system was transferred into a separatory funnel for separation. The organic phase was washed with 100 mL of saturated brine for 3 times, and white solid acrylic-8-nonene-l-yl ester was obtained by drying, with a yield of 89.0 g, and a yield of 93.0%.

[0027] Olefin metathesis reaction: 80.0 g of the prepared acrylic-8-nonene-l-yl ester was dissolved in 800 mL of dichloromethane, and oxygen was removed by nitrogen bubbling. Then, 0.4 g of Grubbs second-generation catalyst was added into the solution under nitrogen protection, and the temperature was raised to 40°C, and the reaction was carried out for 4 hours. After the reaction was completed, most of the solvent was removed by distillation under reduced pressure, and the residue was dissolved in 240 mL of mixed solvent (dichloromethane: n-hexane = 2: 1), and the temperature was lowered to 5°C for recrystallization. White solid was precipitated, and compound (II) was obtained by filtration and drying, with a yield of 61.8 g, and 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 into a 500 mL single-necked flask, and the temperature was raised to 75°C, and the reaction was carried out for 2 hours. After the reaction was completed, ethanol was removed by distillation under reduced pressure, and concentrated hydrochloric acid was added into the residual aqueous solution drop by drop, and the pH of the solution was adjusted to 3-4. Then, 300 mL of ethyl acetate was added for extraction for 3 times. After separation, the ethyl acetate layer was dried to obtain propolis acid crude product, with a yield of 68.0 g. The crude product was recrystallized in 180 mL of mixed solvent (petroleum ether: ethyl acetate = 2: 1) at 0°C, and white solid was precipitated. After filtration and drying, propolis acid pure product was obtained, with a yield of 62.5 g, and a yield of 94.1%. The purity was 99.0% as detected by HPLC (high performance liquid chromatography), and the spectrum was as shown in Figure 2 . The H spectrum was as shown in Figure 1 .

[0029] 1 HNMR (CDC13, δ (ppm), TMS): δ 1.33-1.58 (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 a preparation experiment of propolis acid.

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

[0033] Example 3

[0034] This example provides a preparation experiment of royal jelly acid.

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

[0036] Example 4

[0037] This example provides a preparation experiment of royal jelly acid.

[0038] In the esterification reaction, 200 mL of tetrahydrofuran was replaced by 200 mL of 1,4-dioxane, and the rest of the raw materials were the same as in Example 1. All raw materials were added to a 500 mL three-necked flask, and heating and stirring were started. The temperature was raised to 80°C, and the reaction was carried out for 4 h. The rest of the operations were the same as in Example 1; 89.6 g of acrylic acid-8-nonen-1-yl ester was obtained with a yield of 93.6%. The subsequent operations were the same as in Example 1 to prepare pure royal jelly acid.

[0039] Example 5

[0040] This example provides a preparation experiment of royal jelly acid.

[0041] In the esterification reaction, 200 mL of tetrahydrofuran was replaced by 200 mL of toluene, and the rest of the raw materials were the same as in Example 1. All raw materials were added to a 500 mL three-necked flask, and heating and stirring were started. The temperature was raised to 80°C, and the reaction was carried out for 4 h. The rest of the operations were the same as in Example 1; 87.5 g of acrylic acid-8-nonen-1-yl ester was obtained with a yield of 91.4%. The subsequent operations were the same as in Example 1 to prepare pure royal jelly acid.

[0042] Example 6

[0043] This example provides a preparation experiment of royal jelly acid.

[0044] In the olefin metathesis reaction, 0.4 g Grubbs second generation catalyst was replaced by 0.4 g Grubbs first generation catalyst, and the temperature was raised to 40 °C for 3 h. The rest of the operation was the same as Example 1; 59.3 g of compound (II) was obtained with a yield of 86.5%. The subsequent operation was the same as Example 1, and pure royal jelly acid was prepared.

[0045] Example 7

[0046] This example provides a preparation experiment of royal jelly acid.

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

[0048] Example 8

[0049] This example provides a preparation experiment of royal jelly acid.

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

[0051] Example 9

[0052] This example provides a preparation experiment of royal jelly acid.

[0053] In the hydrolysis and acidification reaction, the reaction system was raised to 60 °C for 6 h. The rest of the operation was the same as Example 1; 61.9 g of pure royal jelly acid was obtained with a yield of 93.2%, and the purity was 98.9% detected by HPLC (high performance liquid chromatography).

[0054] Example 10

[0055] This example provides a preparation experiment of royal jelly acid.

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

[0057] Example 11

[0058] This embodiment provides an application experiment of royal jelly acid.

[0059] The royal jelly acid prepared in Example 1 was dissolved in pentylene glycol 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. 10 μL of each sample solution was mixed thoroughly with 190 μL of 0.25 mmol / L ABTS working solution to obtain the ABTS working solution. Similarly, 10 μL of each sample solution was mixed thoroughly with 190 μL of pentylene glycol to obtain the pentylene glycol solution. All ABTS working solution and pentylene glycol solutions were incubated at room temperature for 6 minutes, and absorbance was measured 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 blank pentanediol is denoted as A3. The ABTS free radical scavenging rate is calculated according to the formula: ABTS scavenging rate = [1-(A1-A2) / A3]×100%. The positive control group consisted of vitamin C loaded 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 were as follows... Figure 3 , Figure 4 The results are shown in Table 1.

[0060] Table 1. Free radical scavenging rate of royal jelly acid

[0061]

[0062] Depend on Figure 3 It can be seen that the IC50 of the positive control VC is... 50 The concentration was 0.251 μmol / mL, falling within the range of 0.23–0.40 μmol / mL; therefore, the experimental system is considered effective. (See Table 1 and...) Figure 4 It can be seen that the ABTS scavenging rate IC50 of royal jelly acid is... 50 With a concentration of 50.418 μmol / mL, the royal jelly acid prepared in this invention exhibits excellent antioxidant effects.

[0063] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0064] Obviously, many modifications and variations of the present application are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method for preparing royal jelly acid, characterized by, The method comprises the following steps: 9-bromo-1 nonene and acrylic acid are subjected to esterification in the presence of an organic solvent and a base to obtain 8-nonen-1-yl acrylate, as shown in formula I; The 8-nonen-1-yl acrylate is subjected to olefin metathesis in the presence of a catalyst to obtain a compound as shown in formula II; After hydrolysis under alkaline conditions and acidification, royal jelly acid is obtained; ； Ⅰ Ⅱ。 2. The production method according to claim 1, characterized by, The organic solvent is any one of dichloromethane, tetrahydrofuran, toluene, 1,4-dioxane and N,N-dimethylformamide; The base is any one of potassium carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, triethylamine, pyridine, N-methylmorpholine and DBU; 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, The 9-bromo-1 nonene, the acrylic acid, the organic solvent and the base are mixed and heated to 60-70 DEG C, and then reacted for 4-6 hours, and then cooled to room temperature, and then subjected to liquid separation, and then the organic phase is reserved, and then the 8-nonen-1-yl acrylate is obtained after purification; The amount 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.

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