Synthesis method and application of high-purity somatotropin

Abstract

This invention discloses a method for synthesizing high-purity Bosein and its application, belonging to the field of Bosein synthesis technology. The method for synthesizing high-purity Bosein of this invention includes the following steps: S1. Dispersing xylose, deionized water, and catalyst by stirring to obtain a mixture A; S2. Dissolving acetylacetone in tetrahydrofuran, then adding it to mixture A, then heating the reaction, cooling, filtering, washing the filtrate with ethyl acetate to remove acetylacetone, collecting the aqueous layer, and distilling under reduced pressure to obtain 1-C-(β-D-xylanopyranosyl)acetone; S3. Mixing 1-C-(β-D-xylanopyranosyl)acetone and anhydrous ethanol, adding sodium triacetoxyborohydride at 0-5°C and stirring to obtain Bosein; the catalyst is obtained by thermal polymerization of dicyandiamide as a precursor and modified dendritic nano-silica spheres as a carrier; the modified dendritic nano-silica spheres are obtained by reacting dendritic nano-silica spheres with imidazole after chlorination functionalization.

Description

Technical Field

[0001] This invention relates to the field of Bosein synthesis technology, specifically to a method for synthesizing high-purity Bosein and its application. Background Technology

[0002] As a core ingredient in anti-aging cosmetics, the market demand for Boseine continues to grow. Its synthesis uses D-xylose as a raw material, through intermediate preparation and reduction reactions. However, traditional processes rely on alkaline catalysts such as sodium hydroxide, which have significant drawbacks: First, while alkaline catalysts like sodium hydroxide can catalyze the reaction, they have poor selectivity and are prone to side reactions, resulting in an intermediate conversion rate of less than 85%, low product purity (impurities > 5%), and difficulty in separating the reactant from the product, requiring frequent replacement and generating large amounts of alkaline waste liquid, increasing treatment costs and pollution risks. Second, strong alkaline catalysts corrode reaction equipment, shortening production line lifespan and posing leakage risks during operation, threatening production safety. Third, product separation is complex, requiring cumbersome processes such as acid neutralization and multiple crystallizations to separate Boseine, with a yield of only 60%–70%, and residual alkaline liquid affecting product stability.

[0003] Therefore, there is an urgent need to develop a method for synthesizing Bosein with high yield and high purity. Summary of the Invention

[0004] The purpose of this invention is to provide a method for synthesizing high-purity Bosein and its application, so as to solve the technical problems mentioned in the background art.

[0005] The technical solution to achieve the objective of this invention is: In a first aspect, the present invention provides a method for synthesizing high-purity Bosein, comprising the following steps: S1. Stir xylose, deionized water and catalyst for 10-20 minutes to obtain mixture A; S2. Dissolve acetylacetone in tetrahydrofuran, then add mixture A, then heat the reaction, cool, filter and collect the filtrate, wash with ethyl acetate to remove acetylacetone, collect the aqueous layer, and distill under reduced pressure to obtain 1-C-(β-D-xylanosyl)acetone; S3. Mix 1-C-(β-D-xylopyranosyl)acetone and anhydrous ethanol, add sodium triacetoxyborohydride at 0~5℃ and stir for 4.5~5.5 h. After the reaction is complete, slowly add hydrochloric acid to adjust the pH to neutral, add ethyl acetate to extract and separate the liquid, take the organic phase and evaporate to dryness to obtain bosine.

[0006] Furthermore, the catalyst is obtained by thermal polymerization using dicyandiamide as a precursor and modified dendritic nano silica spheres as a carrier; the amount of the catalyst is (60~100) mg / 10 mmol xylose.

[0007] Further, the catalyst is prepared as follows: 6 parts by mass of dicyandiamide and 80-100 parts by mass of ethanol solution are heated and stirred at 88-92°C until completely dissolved. Then, 8-10 parts by mass of modified dendritic nano silica spheres are added, and the mixture is heated and stirred until the ethanol evaporates to dryness. Then, under nitrogen protection, the temperature is raised to 500-600°C and held for 2-3 hours in a tube furnace to obtain the catalyst.

[0008] Furthermore, the modified dendritic nano silica spheres are obtained by reacting dendritic nano silica spheres with imidazole after chlorination functionalization.

[0009] Further, the modified dendritic nano silica spheres are prepared as follows: 0.5 parts by mass of chlorine-functionalized dendritic nano silica spheres and 120-150 parts by mass of ethanol are mixed and stirred to disperse evenly. Then, a 1M imidazole ethanol solution is added, and the mixture is stirred at 300-500 rpm for 20-40 min under nitrogen protection. Subsequently, the mixture is reacted at 65-75℃ for 47-49 h. After cooling to room temperature, the ethanol is removed by vacuum distillation. Then, the mixture is washed with toluene and dried under vacuum to obtain the modified dendritic nano silica spheres.

[0010] Furthermore, the mass of the imidazole is 0.13 to 0.15 times the mass of the chlorinated dendritic silica nanospheres.

[0011] Further, the preparation steps of the chlorine-functionalized dendritic silica nanospheres are as follows: 0.5 parts by mass of dendritic silica nanospheres and 130-150 parts by mass of toluene are added to a flask and mixed and stirred until evenly dispersed. Then, 12-13 parts by mass of 3-chloropropyltriethoxysilane are added and refluxed for 23-25 ​​hours. After the reaction is completed, the solid phase is filtered out and washed three times with anhydrous ethanol. Then, it is placed in a vacuum oven at 40-50°C and dried for 11-13 hours to obtain chlorine-functionalized dendritic silica nanospheres.

[0012] Further, the preparation steps of the dendritic nano-silica spheres are as follows: 70 parts by mass of deionized water, 13-15 parts by mass of n-hexane, and 8-10 parts by mass of anhydrous ethanol are added sequentially to a flask and stirred thoroughly until homogeneous. Then, 0.5 parts by mass of hexadecyltrimethylammonium bromide is added and stirred until homogeneous to form an emulsion. Then, 5.1-5.3 parts by mass of tetraethyl orthosilicate and 0.72-0.8 parts by mass of ammonia are added and stirred at 1200-1500 r / min for 3-5 h at room temperature. 1.1-1.2 parts by mass of hydrochloric acid are added to terminate the alkaline catalytic reaction. The solid phase is then separated by centrifugation, washed once with anhydrous ethanol, and dried in a vacuum oven at 40-50℃ for 11-13 h. Then, it is ground and calcined in a tube furnace at 500-600℃ under air conditions for 7-9 h to obtain dendritic nano-silica spheres.

[0013] Furthermore, the reaction temperature in step S2 is 40~50℃, and the reaction time is 50~70min.

[0014] Secondly, the present invention provides an application of high-purity BOXIN, wherein the BOXIN synthesized according to the synthesis method of high-purity BOXIN according to the first aspect is applied in the field of cosmetics.

[0015] By adopting the above technical solution, the present invention has the following beneficial effects: (1) The synthesis steps of the high-purity Bosein of the present invention are as follows: First, xylose and deionized water are stirred under the action of a catalyst to obtain a mixture A; then, acetylacetone is dissolved in tetrahydrofuran and slowly added to the mixture A and heated to react. After the reaction is completed, the mixture is cooled and filtered. The filtrate is washed with ethyl acetate to remove residual acetylacetone. The aqueous layer is collected and distilled under reduced pressure to obtain the key intermediate 1-C-(β-D-pyranoxylosyl)acetone, with a conversion rate of up to 99.6%. The conversion rate is still above 95% after the catalyst is recycled 10 times, which significantly improves the utilization efficiency of raw materials and reduces production costs. Next, the intermediate is mixed with anhydrous ethanol and sodium triacetoxyborohydride is slowly added at low temperature for reduction reaction. After the reaction is completed, the pH of the system is adjusted to neutral with hydrochloric acid. The organic phase is separated by ethyl acetate extraction and the solvent is removed by rotary evaporation. Finally, Bosein with a purity of over 90% is obtained. This synthesis process avoids the corrosiveness and separation problems of traditional strong base catalysts, has a high conversion rate and high product purity, and the operating conditions are mild with low impact on equipment.

[0016] (2) The catalyst of the present invention is obtained by thermal polymerization of dicyandiamide as a precursor and modified dendritic nano silica spheres as a carrier; the amount of the catalyst is (60~100) mg / 10 mmol xylose; the catalyst has excellent catalytic activity and cycle stability. In the reaction of preparing xylose intermediates, the initial conversion rate can reach 99.6%, and after 10 consecutive cycles, the conversion rate can still be maintained at more than 95%, which has excellent reusability; compared with traditional alkaline catalysts, this catalyst avoids the problems of strong corrosion and complex product separation, while achieving high conversion rate and product purity.

[0017] (3) Under the action of a catalyst, the reaction temperature in the preparation of xylose intermediates in this invention is only 40~50℃, the reaction time is shortened to 50~70min, the reaction conditions are mild and the energy consumption is low, and the production cycle is greatly shortened.

[0018] (4) In the preparation of the catalyst of the present invention, firstly, the dendritic nano silica spheres are subjected to chlorine functionalization treatment to graft chlorine groups onto their surface, and then react with imidazole molecules to form a polyimide chloride functional layer on the support surface through the reaction polymerization of chlorine atoms with secondary and tertiary amines in the imidazole structure; then, using dicyandiamide as a precursor, the modified dendritic nano silica spheres are used as a support for thermal polymerization, so that graphitic carbonitrides are attached to the support surface in situ and embedded in the polyimide chloride network; the high specific surface area and three-dimensional mesoporous structure of the modified dendritic nano silica spheres provide active site attachment space for graphitic carbonitrides, increase the collision probability between reactant molecules and catalyst active centers, and significantly reduce mass transfer resistance; the polyimide chloride network not only acts as an "anchor" to enhance the binding strength of graphitic carbonitrides on the support surface, but its own weakly basic sites also participate in the catalytic reaction, forming a "dual active center" effect, further improving the catalytic efficiency, and the resulting catalyst has excellent catalytic activity and cycle stability. Attached Figure Description

[0019] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein... Figure 1 This is a schematic diagram of the structure of 1-C-(β-D-xylanosyl)acetone according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of Bosein according to an embodiment of the present invention. Detailed Implementation

[0021] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0023] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0024] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0025] Example 1 A method for synthesizing high-purity Bosein, comprising the following steps: S1. Stir 20 mmol xylose, 50 g deionized water and 120 mg catalyst for 10 min to obtain mixture A; S2. Dissolve 22 mol of acetylacetone in 10 mL of tetrahydrofuran, then add mixture A, then heat to 40 °C and react for 70 min, cool, filter and collect the filtrate, wash with ethyl acetate to remove acetylacetone, collect the aqueous layer, and distill under reduced pressure to obtain 1-C-(β-D-xylanosyl)acetone; S3. Mix 1-C-(β-D-xylopyranosyl)acetone and 250 mL of anhydrous ethanol, add 28 mmol of sodium triacetoxyborohydride at 0 °C and stir for 5.5 h. After the reaction is complete, slowly add 2 M hydrochloric acid to adjust the pH to neutral, add ethyl acetate to extract and separate the liquid, take the organic phase and evaporate to dryness, purify by column chromatography with the eluent polarity of ethyl acetate:ethanol = 20:1, to obtain bosine.

[0026] The catalyst preparation steps are as follows: 6 parts by mass of dicyandiamide and 80 parts by mass of ethanol solution are heated and stirred at 88°C until completely dissolved. Then, 8 parts by mass of modified dendritic nano silica balls are added, and the mixture is heated and stirred until the ethanol evaporates to dryness. Then, under nitrogen protection, the temperature is raised to 500°C and held for 3 hours in a tube furnace to obtain the catalyst.

[0027] The modified dendritic silica nanospheres are prepared as follows: 0.5 parts by mass of chlorine-functionalized dendritic silica nanospheres and 120 parts by mass of ethanol are mixed and stirred to disperse evenly. Then, a 1M imidazole 95% ethanol solution is added, wherein the mass of imidazole is 0.13 times the mass of the chlorine-functionalized dendritic silica nanospheres. The mixture is stirred at 300 rpm for 40 min under nitrogen protection, and then reacted at 65℃ for 49 h. After cooling to room temperature, the ethanol is removed by vacuum distillation, followed by washing with toluene and vacuum drying to obtain the modified dendritic silica nanospheres.

[0028] The preparation steps of chlorine-functionalized dendritic silica nanospheres are as follows: 0.5 parts by mass of dendritic silica nanospheres and 130 parts by mass of toluene are added to a flask and mixed and stirred until evenly dispersed. Then, 12 parts by mass of 3-chloropropyltriethoxysilane are added and refluxed for 23 hours. After the reaction is completed, the solid phase is separated by filtration, washed three times with anhydrous ethanol, and then dried in a vacuum oven at 40°C for 13 hours to obtain chlorine-functionalized dendritic silica nanospheres.

[0029] The preparation steps of dendritic nano-silica spheres are as follows: 70 parts by mass of deionized water, 13 parts by mass of n-hexane and 8 parts by mass of anhydrous ethanol are added to a flask in sequence and stirred thoroughly. Then, 0.5 parts by mass of hexadecyltrimethylammonium bromide is added and stirred until an emulsion is formed. Then, 5.1 parts by mass of tetraethyl orthosilicate and 0.72 parts by mass of ammonia are added and stirred at 1200 r / min for 3 h at room temperature. 1.1 parts by mass of 1M hydrochloric acid is added to terminate the alkaline catalytic reaction. The solid phase is then separated by centrifugation, washed once with anhydrous ethanol, and dried in a vacuum oven at 40℃ for 13 h. Then, it is ground and calcined at 500℃ in air for 9 h in a tube furnace to obtain dendritic nano-silica spheres.

[0030] Example 2 A method for synthesizing high-purity Bosein, comprising the following steps: S1. Stir 20 mmol xylose, 50 g deionized water and 160 mg catalyst for 15 min to obtain mixture A; S2. Dissolve 22 mol of acetylacetone in 10 mL of tetrahydrofuran, then add mixture A, heat to 45 °C and react for 60 min, cool, filter and collect the filtrate, wash with ethyl acetate to remove acetylacetone, collect the aqueous layer, and distill under reduced pressure to obtain 1-C-(β-D-xylanosyl)acetone. S3. Mix 1-C-(β-D-xylopyranosyl)acetone and 250 mL of anhydrous ethanol, add 28 mmol of sodium triacetoxyborohydride at 0 °C and stir for 5 h. After the reaction is complete, slowly add 2 M hydrochloric acid to adjust the pH to neutral, add ethyl acetate to extract and separate the liquid, take the organic phase and evaporate to dryness, purify by column chromatography with the eluent polarity of ethyl acetate:ethanol = 20:1, to obtain bosine.

[0031] The catalyst preparation steps are as follows: 6 parts by mass of dicyandiamide and 90 parts by mass of ethanol solution are heated and stirred at 90°C until completely dissolved. Then, 9 parts by mass of modified dendritic nano silica spheres are added, and the mixture is heated and stirred until the ethanol evaporates to dryness. Then, under nitrogen protection, the temperature is raised to 550°C and held for 2.5 hours in a tube furnace to obtain the catalyst.

[0032] The modified dendritic silica nanospheres are prepared as follows: 0.5 parts by mass of chlorine-functionalized dendritic silica nanospheres and 120 parts by mass of ethanol are mixed and stirred to disperse evenly. Then, a 1M imidazole 95% ethanol solution is added, wherein the mass of imidazole is 0.14 times the mass of the chlorine-functionalized dendritic silica nanospheres. The mixture is stirred at 400 rpm for 30 min under nitrogen protection, and then reacted at 70℃ for 48 h. After cooling to room temperature, the ethanol is removed by vacuum distillation, followed by washing with toluene and vacuum drying to obtain the modified dendritic silica nanospheres.

[0033] The preparation steps of chlorine-functionalized dendritic silica nanospheres are as follows: 0.5 parts by mass of dendritic silica nanospheres and 140 parts by mass of toluene are added to a flask and mixed and stirred until evenly dispersed. Then, 12.5 parts by mass of 3-chloropropyltriethoxysilane are added and refluxed for 24 hours. After the reaction is completed, the solid phase is separated by filtration, washed three times with anhydrous ethanol, and then dried in a vacuum oven at 45°C for 12 hours to obtain chlorine-functionalized dendritic silica nanospheres.

[0034] The preparation steps of dendritic nano-silica spheres are as follows: 70 parts by mass of deionized water, 14 parts by mass of n-hexane and 9 parts by mass of anhydrous ethanol are added to a flask in sequence and stirred thoroughly. Then, 0.5 parts by mass of hexadecyltrimethylammonium bromide is added and stirred until an emulsion is formed. Then, 5.2 parts by mass of tetraethyl orthosilicate and 0.76 parts by mass of ammonia are added and stirred at 1300 r / min for 4 h at room temperature. 1.15 parts by mass of 1M hydrochloric acid is added to terminate the alkaline catalytic reaction. The solid phase is then separated by centrifugation, washed once with anhydrous ethanol, and dried in a vacuum oven at 45℃ for 12 h. Then, it is ground and calcined at 550℃ in air for 8 h in a tube furnace to obtain dendritic nano-silica spheres.

[0035] Example 3 A method for synthesizing high-purity Bosein, comprising the following steps: S1. Stir 20 mmol xylose, 50 g deionized water and 200 mg catalyst for 20 min to obtain mixture A; S2. Dissolve 22 mol of acetylacetone in 10 mL of tetrahydrofuran, then add mixture A, heat to 50 °C and react for 50 min, cool, filter and collect the filtrate, wash with ethyl acetate to remove acetylacetone, collect the aqueous layer, and distill under reduced pressure to obtain 1-C-(β-D-xylanosyl)acetone. S3. Mix 1-C-(β-D-xylanosyl)acetone and 250 mL of anhydrous ethanol, add 28 mmol of sodium triacetoxyborohydride at 5 °C and stir for 5.5 h. After the reaction is complete, slowly add 2 M hydrochloric acid to adjust the pH to neutral, add ethyl acetate to extract and separate the liquid, take the organic phase and evaporate to dryness, purify by column chromatography with the eluent polarity of ethyl acetate:ethanol = 20:1, to obtain bosine.

[0036] The catalyst preparation steps are as follows: 6 parts by mass of dicyandiamide and 100 parts by mass of ethanol solution are heated and stirred at 92°C until completely dissolved. Then, 10 parts by mass of modified dendritic nano silica balls are added, and the mixture is heated and stirred until the ethanol evaporates to dryness. Then, under nitrogen protection, the temperature is raised to 600°C and held for 2 hours in a tube furnace to obtain the catalyst.

[0037] The modified dendritic silica nanospheres are prepared as follows: 0.5 parts by mass of chlorine-functionalized dendritic silica nanospheres and 150 parts by mass of ethanol are mixed and stirred to disperse evenly. Then, a 1M imidazole ethanol solution is added, wherein the mass of imidazole is 0.15 times the mass of the chlorine-functionalized dendritic silica nanospheres. The mixture is stirred at 500 rpm for 40 min under nitrogen protection, and then reacted at 75℃ for 47 h. After cooling to room temperature, the ethanol is removed by vacuum distillation, followed by washing with toluene and vacuum drying to obtain the modified dendritic silica nanospheres.

[0038] The preparation steps of chlorine-functionalized dendritic silica nanospheres are as follows: 0.5 parts by mass of dendritic silica nanospheres and 150 parts by mass of toluene are added to a flask and mixed and stirred until evenly dispersed. Then, 13 parts by mass of 3-chloropropyltriethoxysilane are added and refluxed for 25 h. After the reaction is completed, the solid phase is separated by filtration, washed three times with anhydrous ethanol, and then dried in a vacuum oven at 50 °C for 11 h to obtain chlorine-functionalized dendritic silica nanospheres.

[0039] The preparation steps of dendritic nano-silica spheres are as follows: 70 parts by mass of deionized water, 15 parts by mass of n-hexane and 10 parts by mass of anhydrous ethanol are added to a flask in sequence and stirred thoroughly. Then, 0.5 parts by mass of hexadecyltrimethylammonium bromide is added and stirred until an emulsion is formed. Then, 5.3 parts by mass of tetraethyl orthosilicate and 0.8 parts by mass of ammonia are added and stirred at 1500 r / min for 5 h at room temperature. 1.2 parts by mass of hydrochloric acid is added to terminate the alkaline catalytic reaction. The solid phase is then separated by centrifugation, washed once with anhydrous ethanol, and dried in a vacuum oven at 50 ℃ for 11 h. Then, it is ground and calcined at 600 ℃ in air for 7 h in a tube furnace to obtain dendritic nano-silica spheres.

[0040] Example 4 The only difference between Examples 4-7 and Example 2 is that the amount of catalyst used is 60 mg / 10 mmol xylose, 70 mg / 10 mmol xylose, 90 mg / 10 mmol xylose, and 100 mg / 10 mmol xylose.

[0041] Comparative Example 1 The only difference between Comparative Example 1 and Example 2 is that the catalyst was obtained by thermal polymerization using dicyandiamide as a precursor and dendritic nano silica spheres as a carrier.

[0042] Comparative Examples 2-3 The only difference between Comparative Examples 2 and 3 and Example 2 is that the catalyst dosage is 50 mg / 10 mmol xylose and 55 mg / 10 mmol xylose, respectively.

[0043] Comparative Example 4 The difference between Comparative Example 4 and Example 2 is that Boseine is synthesized using a traditional synthesis process with sodium hydroxide as a catalyst.

[0044] Example of effect The catalyst filtered in step S2 was washed three times each with ethanol and water, dried under vacuum, and then used in the next reaction.

[0045] Table 1 below shows the yield of 1-C-(β-D-pyranoxyl)acetone, the intermediate for Bosein in Examples 1-7 and Comparative Examples 1-4, the yield after 10 cycles of catalyst reuse, and the purity of Bosein.

[0046] Table 1 As shown in Table 1, the intermediates of Bosein prepared in Examples 1-7 have high yields and high purity, and the yield is still over 95% after the catalyst is reused 10 times.

[0047] Comparative Example 1 catalyst was obtained by thermal polymerization using dicyandiamide as a precursor and dendritic nano silica spheres as a carrier. The intermediate of Bosein prepared in Example 2 had a high yield and high purity of Bosein. The yield of the catalyst decreased significantly after being reused 10 times, indicating that the introduction of polyimide chloride can promote the improvement of the catalyst's cycle stability and catalytic activity, thereby effectively improving the yield of Bosein and having a positive promoting effect on improving the purity of Bosein.

[0048] Comparative Examples 2 and 3 differed only in the catalyst dosage: 50 mg / 10 mmol xylose and 55 mg / 10 mmol xylose. Examples 2 and 4-7 had catalyst dosages of 80 mg / 10 mmol xylose, 60 mg / 10 mmol xylose, 70 mg / 10 mmol xylose, 90 mg / 10 mmol xylose, and 100 mg / 10 mmol xylose, respectively. As the catalyst dosage increased, the intermediate yield increased and then stabilized, indicating that the optimal catalyst dosage was 60 mg / 10 mmol xylose.

[0049] Comparative Example 4: Bosein was synthesized using a traditional synthesis process with sodium hydroxide as a catalyst. The intermediate yield was only 90.4%, and the purity was 91.8%, which was far lower than that of the examples.

[0050] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for synthesizing high-purity Bosein, characterized in that the steps include... include: S1. Stir xylose, deionized water and catalyst for 10-20 minutes to obtain mixture A; S2. Dissolve acetylacetone in tetrahydrofuran, then add mixture A, then heat the reaction, cool, filter and collect the filtrate, wash with ethyl acetate to remove acetylacetone, collect the aqueous layer, and distill under reduced pressure to obtain 1-C-(β-D-xylanosyl)acetone; S3. Mix 1-C-(β-D-xylopyranosyl)acetone and anhydrous ethanol, add sodium triacetoxyborohydride at 0~5℃ and stir for 4.5~5.5 h. After the reaction is complete, slowly add hydrochloric acid to adjust the pH to neutral, add ethyl acetate to extract and separate the liquid, take the organic phase and evaporate to dryness to obtain bosine.

2. The method for synthesizing high-purity Bosein according to claim 1, characterized in that, The catalyst is obtained by thermal polymerization of dicyandiamide as a precursor and modified dendritic nano silica spheres as a carrier; the amount of the catalyst is (60~100) mg / 10 mmol xylose.

3. The method for synthesizing high-purity Bosein according to claim 2, characterized in that, The catalyst is prepared as follows: 6 parts by mass of dicyandiamide and 80-100 parts by mass of ethanol solution are heated and stirred at 88-92°C until completely dissolved. Then, 8-10 parts by mass of modified dendritic nano silica balls are added, and the mixture is heated and stirred until the ethanol evaporates to dryness. Then, under nitrogen protection, the temperature is raised to 500-600°C in a tube furnace and held for 2-3 hours to obtain the catalyst.

4. The method for synthesizing high-purity Bosein according to claim 3, characterized in that, The modified dendritic silica nanospheres are obtained by reacting dendritic silica nanospheres with imidazole after chlorination functionalization.

5. The method for synthesizing high-purity Bosein according to claim 4, characterized in that, The modified dendritic nano silica spheres are prepared as follows: 0.5 parts by mass of chlorine-functionalized dendritic nano silica spheres and 120-150 parts by mass of ethanol are mixed and stirred to disperse evenly. Then, a 1M imidazole ethanol solution is added, and the mixture is stirred at 300-500 rpm for 20-40 min under nitrogen protection. Subsequently, the mixture is reacted at 65-75℃ for 47-49 h. After cooling to room temperature, the ethanol is removed by vacuum distillation. The mixture is then washed with toluene and dried under vacuum to obtain the modified dendritic nano silica spheres.

6. The method for synthesizing high-purity Bosein according to claim 5, characterized in that, The mass of the imidazole is 0.13 to 0.15 times the mass of the chlorine-functionalized dendritic silica nanospheres.

7. The method for synthesizing high-purity Bosein according to claim 6, characterized in that, The preparation steps of the chlorine-functionalized dendritic silica nanospheres are as follows: 0.5 parts by mass of dendritic silica nanospheres and 130-150 parts by mass of toluene are added to a flask and mixed and stirred until evenly dispersed. Then, 12-13 parts by mass of 3-chloropropyltriethoxysilane are added and refluxed for 23-25 ​​hours. After the reaction is completed, the solid phase is separated by filtration, washed three times with anhydrous ethanol, and then dried in a vacuum oven at 40-50℃ for 11-13 hours to obtain chlorine-functionalized dendritic silica nanospheres.

8. The method for synthesizing high-purity Bosein according to claim 7, characterized in that, The preparation steps of the dendritic nano-silica spheres are as follows: 70 parts by mass of deionized water, 13-15 parts by mass of n-hexane and 8-10 parts by mass of anhydrous ethanol are added to a flask in sequence and stirred thoroughly until homogeneous. Then, 0.5 parts by mass of hexadecyltrimethylammonium bromide is added and stirred until homogeneous to form an emulsion. Then, 5.1-5.3 parts by mass of tetraethyl orthosilicate and 0.72-0.8 parts by mass of ammonia are added and stirred at 1200-1500 r / min for 3-5 h at room temperature. 1.1-1.2 parts by mass of hydrochloric acid are added to terminate the alkaline catalytic reaction. The solid phase is then separated by centrifugation, washed once with anhydrous ethanol, and dried in a vacuum oven at 40-50℃ for 11-13 h. The solid phase is then ground and calcined in a tube furnace at 500-600℃ for 7-9 h under air conditions to obtain dendritic nano-silica spheres.

9. The method for synthesizing high-purity Bosein according to claim 1, characterized in that, The reaction temperature in step S2 is 40~50℃, and the reaction time is 50~70min.

10. An application of high-purity Bosein, characterized in that, The high-purity BOXER synthesized by the method according to any one of claims 1 to 9 is used in the cosmetics field.

Images