Process for purifying 1-c-(beta-xylopyranosyl)-propanone

Abstract

The application discloses a purification method of 1-C-(beta-pyranylyl) acetone, which comprises the following steps: mixing xylose, acetylacetone and an alkaline catalyst in a solvent to react, synthesizing 1-C-(beta-pyranylyl) acetone, filtering out the alkaline catalyst after the reaction is completed, and obtaining a first intermediate product; diluting the first intermediate product with a diluent, adding a first organic solvent to extract acetylacetone and small-polarity impurities in the first intermediate product, discarding the organic layer, and obtaining a second intermediate product; loading the second intermediate product on a macroporous adsorption resin, eluting the second intermediate product with an eluent, removing sugar impurities and pigments in the second intermediate product, and obtaining effluent; performing rotary evaporation on the effluent, and obtaining a solid-oil mixed product; mixing the solid-oil mixed product with a second organic solvent, and performing cooling crystallization, so as to precipitate 1-C-(beta-pyranylyl) acetone with required purity and sensory quality.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological medicine, more particularly, to a purification method of 1-C-(β-xylopyranosyl)-propanone. BACKGROUND

[0002] Bioss, chemical name hydroxypropyl tetrahydropyran triol, is a kind of bioactive ingredients for cosmetics. It can promote the generation and construction of protein polysaccharide in extracellular matrix, and absorb water, make the matrix gelatinous, increase the tightness of cells and skin, and also stimulate the regeneration of aging cells and prevent skin aging. And non-toxic and no residue, this property further increases the application possibility of bioss in the fields of biology, medicine, cosmetics and the like.

[0003] The reported bioss synthesis route is as follows:

[0004]

[0005] The synthesis of bioss needs two steps, first, xylose and acetylacetone are synthesized into 1-C-(β-xylopyranosyl)-propanone under alkaline conditions, and then bioss is obtained by reduction. Among them, the purity of 1-C-(β-xylopyranosyl)-propanone has a great influence on the sensory quality such as appearance and odor of the final product bioss after reduction.

[0006] At present, the purification of intermediate product 1-C-(β-xylopyranosyl)-propanone mainly adopts acetylation protection and silica gel column chromatography. Chinese patent CN113735811A discloses a method for synthesizing bioss by acetylation protection and then reduction, and the second intermediate product is obtained by acetylation reaction of 1-C-(β-xylopyranosyl)-propanone crude product and acetylation reagent, which is easy to purify. Not only increases the reaction steps, but also the acetylation reagent will be converted into the corresponding acid after the reaction is completed, so that the acid smell in the final product bioss is difficult to remove. US7049300B2 discloses a method by using cation exchange resin Dowex 50X-200, which can only remove cations in the reaction system, and cannot remove pigments and other impurities in the crude product of intermediate product. Moreover, as a strong acid resin, Dowex 50X-200 has poor repeatability and is not suitable for industrial production. Junfeng Wang and Qin Li et al. purify 1-C-(β-xylopyranosyl)-propanone by chromatography silica gel column, which not only consumes a large amount of solvent, but also has a slow chromatography speed, which seriously limits the efficiency required for industrial large-scale production. SUMMARY

[0007] The present application aims at overcoming the above-mentioned defects in the prior art, and provides a method for purifying 1-C-(beta-xylopyranosyl)-propanone, which is optimized and improved so as to make the purity and sensory quality of the 1-C-(beta-xylopyranosyl)-propanone reach the requirements.

[0008] To achieve the above-mentioned object, the technical scheme of the present application is as follows:

[0009] A method for purifying 1-C-(beta-xylopyranosyl)-propanone, comprising the following steps:

[0010] After mixing xylose, acetylacetone and an alkaline catalyst in a solvent, the 1-C-(beta-xylopyranosyl)-propanone is synthesized by reaction, and after the reaction is completed, the alkaline catalyst is removed by filtration to obtain a first intermediate product;

[0011] After the first intermediate product is diluted by a diluent, acetylacetone and small polar impurities in the first intermediate product are removed by adding a first organic solvent for extraction, and the organic layer is discarded to obtain a second intermediate product;

[0012] The second intermediate product is loaded onto a macroporous adsorption resin, and an eluent is used for elution, so as to remove saccharide impurities and pigments in the second intermediate product, and then an effluent is obtained;

[0013] The effluent is subjected to rotary evaporation to obtain a solid-oil mixed product;

[0014] The solid-oil mixed product is mixed with a second organic solvent, and then cooled crystallization is performed to precipitate the 1-C-(beta-xylopyranosyl)-propanone.

[0015] The implementation of the present application has the following beneficial effects:

[0016] The embodiment of the present application optimizes and improves the purification method of 1-C-(β-xylopyranosyl)-propanone, so that the purity and sensory of 1-C-(β-xylopyranosyl)-propanone reach the requirements. In the embodiment of the present application, xylose, acetylacetone and alkaline catalyst are mixed in a solvent to react, after the reaction is completed, the alkaline catalyst is removed by filtration to obtain a first intermediate product; then the first intermediate product diluted is extracted with a first organic solvent to remove acetylacetone and small polar impurities; then the second intermediate product after extraction is separated by macroporous adsorption resin to remove sugar impurities and pigments, and the macroporous adsorption resin has no adsorption performance on 1-C-(β-xylopyranosyl)-propanone, so that the loss of 1-C-(β-xylopyranosyl)-propanone is reduced; then the solid oil mixture evaporated to dryness is mixed with a second organic solvent, and then crystallized after cooling to further purify the impurities and pigments that have not been removed, so that high-purity and high-yield 1-C-(β-xylopyranosyl)-propanone is obtained. Through one-time purification by filtration and extraction, secondary purification by macroporous adsorption resin and three-time purification by crystallization, mutual cooperation is achieved, a large amount of impurities and pigments are removed through early extraction and macroporous adsorption resin purification, so that the high concentration of impurities is avoided, which is not conducive to the precipitation of 1-C-(β-xylopyranosyl)-propanone, and the complete removal of impurities and pigments is further ensured through the crystallization process, so that the yield and purity of 1-C-(β-xylopyranosyl)-propanone are improved. 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 following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0018] Among them:

[0019] Figure 1 The 1-C-(β-xylopyranosyl)-propanone nuclear magnetic resonance hydrogen spectrum of Example 1. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with 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.

[0021] The present application discloses a preparation method of 1-C-(β-xylopyranosyl)-propanone, comprising the following steps:

[0022] 1) mixing xylose, acetylacetone and a basic catalyst in a solvent to react, to synthesize 1-C-(β-xylopyranosyl)-propanone, after the reaction is completed, filtering to remove the basic catalyst to obtain a first intermediate product.

[0023] In specific embodiments, step 1) specifically comprises the following steps:

[0024] 1.1) mixing xylose, acetylacetone and a basic catalyst in a solvent to react at 90-100°C for 5-8h, to synthesize 1-C-(β-xylopyranosyl)-propanone, to obtain a reaction product.

[0025] Specifically, xylose reacts with acetylacetone to synthesize 1-C-(β-xylopyranosyl)-propanone through condensation reaction and hydrolysis decarboxylation in a basic environment.

[0026] In specific embodiments, the molar ratio of xylose, acetylacetone and the basic catalyst is 1.0:(1.0-1.5):(1.0-2.0).

[0027] In specific embodiments, the basic catalyst comprises one or more of sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium hydroxide, potassium hydroxide and lithium hydroxide. Preferably, the basic catalyst is sodium bicarbonate.

[0028] In specific embodiments, the solvent comprises water.

[0029] 1.2) cooling the reaction product to room temperature, the basic catalyst in the reaction product is precipitated, filtering to remove the basic catalyst to obtain the first intermediate product.

[0030] 2) diluting the first intermediate product with a diluent, adding a first organic solvent to extract acetylacetone and small polar impurities in the first intermediate product, discarding the organic layer to obtain a second intermediate product.

[0031] In specific embodiments, step 2) specifically comprises the following steps:

[0032] 2.1) diluting the first intermediate product with a diluent to obtain a diluted first intermediate product.

[0033] In specific embodiments, the diluent is water, which facilitates subsequent resin column purification.

[0034] In specific embodiments, the weight ratio of the diluent to xylose is (0.5-1.5):1.

[0035] 2.2) Add the diluted first intermediate to the first organic solvent and stir until the first organic solvent and the diluted first intermediate are fully mixed. Let stand for 20 min to 30 min to wait for the solution to separate into layers. Discard the organic layer and recover the water layer to remove acetylacetone and small polar impurities generated in step 1) and obtain the second intermediate.

[0036] In one specific embodiment, the extraction is performed 1 to 4 times, with each extraction lasting 20 to 30 minutes and at a temperature of 25°C to 35°C. The water layers after each extraction are combined and recovered.

[0037] In one specific embodiment, the volume of the first organic solvent used in a single application is 0.5 to 1.0 times the volume of the diluted first intermediate product.

[0038] In one specific embodiment, the first organic solvent includes one or more of ethyl acetate, petroleum ether, n-hexane, dichloromethane, and chloroform. Preferably, the first organic solvent is ethyl acetate.

[0039] 3) The second intermediate product is loaded onto a macroporous adsorption resin and eluted with an eluent to remove sugar impurities and pigments from the second intermediate product, thus obtaining the eluent.

[0040] In one specific embodiment, the second intermediate product is loaded onto a macroporous adsorption resin. After all the samples are loaded, elution is performed using an eluent. Pure 1-C-(β-xylanosyl)-acetone is used as a control. Thin-layer chromatography is used for monitoring. Collection is stopped when 1-C-(β-xylanosyl)-acetone disappears, and the eluent after removing sugar impurities and pigments from the second intermediate product is obtained.

[0041] In one specific embodiment, the macroporous adsorption resin has a specific surface area of ​​570 m². 2 / g~700m 2 / g.

[0042] In one specific embodiment, the pore size of the macroporous adsorption resin is 0.3 mm to 1.25 mm.

[0043] Specifically, the pore size and specific surface area of the macroporous adsorption resin are the key to affect its adsorption performance. The adsorption principle of the macroporous adsorption resin is mainly physical adsorption, so the larger the specific surface area, the greater the surface tension, and the higher the adsorption capacity of impurities and pigments. At the same time, the size of the pore size will also affect the adsorption of molecules of different sizes. The comprehensive effect of various factors causes the difference in adsorption capacity of different macroporous adsorption resins, therefore, the macroporous adsorption resin with good pore size and large specific surface area is used in the embodiment of the present application to adsorb and remove the saccharide impurities and pigments from the second intermediate product after extraction, and the macroporous adsorption resin does not have adsorption performance on 1-C-(β-xylopyranosyl)-propanone, thereby reducing the loss of 1-C-(β-xylopyranosyl)-propanone.

[0044] In a specific embodiment, the macroporous adsorption resin comprises one or more of LX-T19, LX-66 and LX-835.

[0045] In a specific embodiment, the weight ratio of the second intermediate product to the adsorption resin is 1:(1-4).

[0046] In a specific embodiment, the eluent comprises one or both of pure water and ethanol. Preferably, the eluent is pure water, and 2-3 column volumes of pure water are used for elution after loading.

[0047] In a specific embodiment, the loading flow rate is 250-350 mL / min.

[0048] In a specific embodiment, the elution flow rate is 300-400 mL / min.

[0049] In a specific embodiment, before loading, the macroporous adsorption resin is also subjected to water washing and activation, and the specific steps are as follows: when activating the macroporous adsorption resin, 2-4 column volumes of pure water are used for elution until the effluent is clear, i.e. the activation of the macroporous adsorption resin is completed.

[0050] In a specific embodiment, after elution, the adsorption resin is also subjected to flushing and regeneration with an ethanol aqueous solution with a volume concentration of 50-95%, and the specific steps are as follows: when regenerating the macroporous adsorption resin, 1-4 column volumes of the ethanol aqueous solution with a volume concentration of 50-95% are used for elution.

[0051] 4) The effluent is subjected to rotary evaporation to obtain a solid-oil mixed product.

[0052] In a specific embodiment, the effluent is added to a rotary evaporation device for rotary evaporation to remove water, the pressure of rotary evaporation is 0.08-0.09 MPa, and the temperature of rotary evaporation is 80-90℃.

[0053] 5) cooling crystallization of the solid oil mixture product after mixing with the second organic solvent to precipitate 1-C-(β-xylopyranosyl)-propanone.

[0054] Specifically, the precipitated crystals are filtered, washed and dried to obtain 1-C-(β-xylopyranosyl)-propanone, which is further purified from impurities and pigments. Since a large amount of impurities has been removed by the previous extraction and macroporous adsorption resin purification, the subsequent crystallization process is reduced, and the high concentration of impurities is avoided, which is not conducive to the precipitation of 1-C-(β-xylopyranosyl)-propanone and affects the yield of 1-C-(β-xylopyranosyl)-propanone.

[0055] In a specific embodiment, the solid oil mixture product is mixed with the second organic solvent, and the obtained solution is filtered to remove the basic catalyst that is not removed in step 1). Then, the filtered solution is heated to 50-65°C until completely dissolved, and then cooled crystallization is carried out at -10-15°C for 12-24h. The precipitated crystals are filtered, washed and dried to obtain 1-C-(β-xylopyranosyl)-propanone.

[0056] In a specific embodiment, the weight ratio of the second organic solvent to the solid oil mixture product is (0.5-2.0):1.

[0057] In a specific embodiment, the second organic solvent includes one or more of acetone, halogenated hydrocarbon, alcohol and acetonitrile. Preferably, the second organic solvent is acetone. Using acetone for crystallization can obtain crystals with good crystal shape, which is conducive to impurity removal and color purification, and has higher yield.

[0058] Compared with the existing acetylation protection and silica gel column chromatography method, the present application first filters and extracts the product to remove the basic catalyst, unreacted acetylacetone and small polar impurities. Then, the second intermediate product after extraction is subjected to macroporous adsorption resin to remove impurities and pigments, thereby removing the sugar impurities and pigments in the reactants. Finally, the solid oil mixture after rotary evaporation is subjected to cooling crystallization to further purify the impurities and pigments that have not been removed, thereby obtaining high-purity and high-yield 1-C-(β-xylopyranosyl)-propanone. The extraction, macroporous adsorption resin and crystallization are mutually coordinated. A large amount of impurities is removed by extraction and macroporous adsorption resin, thereby avoiding the high concentration of impurities that is not conducive to the precipitation of 1-C-(β-xylopyranosyl)-propanone. Further, the complete removal of impurities and pigments is ensured, thereby improving the yield and purity of 1-C-(β-xylopyranosyl)-propanone. Moreover, the purification method of the present application has a simple process flow, does not use a large amount of organic solvent, is safe and environmentally friendly.

[0059] The following are specific embodiments.

[0060] Example 1

[0061] 1) In a 100 L reactor, 10.0 kg of xylose, 8.4 kg of acetylacetone and 8.0 kg of sodium bicarbonate were mixed with 50.0 kg of water and reacted at 100°C for 8 h to synthesize 1-C-(β-xylopyranosyl)-propanone. The reaction product was cooled to room temperature, filtered to remove the precipitated sodium bicarbonate from the reaction product, and a first intermediate product was obtained.

[0062] 2) After the first intermediate product was diluted with 5 kg of water, 5.0 kg of ethyl acetate was added, and the mixture was stirred at 25°C until it was well mixed, and then allowed to stand for 30 min to separate the layers. The organic layer was discarded, and the water layer was recovered. The extraction was repeated twice, and the water layers recovered in each extraction were combined to remove the acetylacetone and small polar impurities generated in step 1), and a second intermediate product was obtained.

[0063] 3) 100 kg of LX-835 having a specific surface area of 680 m2 / g and a pore diameter of 0.5 mm was added to a resin column and activated with 200 kg of water until the effluent was clear. 2

[0064] 4) The second intermediate product was loaded onto the LX-835 obtained in step 3) at a rate of 300 mL / min, and the amount of the second intermediate product loaded was 30 kg. After the loading was completed, the column was eluted with water at a rate of 350 mL / min for 2 column volumes. The elution was followed by thin layer chromatography using 1-C-(β-xylopyranosyl)-propanone as a reference. When 1-C-(β-xylopyranosyl)-propanone disappeared, the collection was stopped, and 60 kg of effluent was obtained. After the elution was completed, the resin was regenerated by eluting it with 2 column volumes of 95% ethanol aqueous solution to be reused.

[0065] 5) The effluent was subjected to rotary evaporation in a rotary evaporator to remove water at a pressure of 0.09 MPa and a temperature of 90°C, and 9.2 kg of a solid-oil mixture was obtained.

[0066] 6) The solid-oil mixture was mixed with 9.2 kg of acetone, and the resulting solution was filtered to remove the sodium bicarbonate not removed in step 1). The filtered solution was heated to 60°C to be completely dissolved, and then cooled to -5°C for 20 h to crystallize. The precipitated crystals were filtered, washed and dried to obtain 7.6 kg of 1-C-(β-xylopyranosyl)-propanone.

[0067] Example 2

[0068] This example differs from Example 1 only in that the extraction was performed once. ​

[0069] The other components and amounts are the same as in Example 1, and 7.2 kg of 1-C-(β-xylopyranosyl)-propanone is obtained according to the preparation method of Example 1.

[0070] Example 3

[0071] This example differs from Example 1 only in that the extraction is performed four times.

[0072] The other components and amounts are the same as in Example 1, and 6.9 kg of 1-C-(β-xylopyranosyl)-propanone is obtained according to the preparation method of Example 1.

[0073] Example 4

[0074] This example differs from Example 1 only in that the first organic solvent is dichloromethane.

[0075] The other components and amounts are the same as in Example 1, and 6.3 kg of 1-C-(β-xylopyranosyl)-propanone is obtained according to the preparation method of Example 1.

[0076] Example 5

[0077] This example differs from Example 1 only in that the first organic solvent is n-hexane.

[0078] The other components and amounts are the same as in Example 1, and 6.8 kg of 1-C-(β-xylopyranosyl)-propanone is obtained according to the preparation method of Example 1.

[0079] Example 6

[0080] This example differs from Example 1 only in that the weight ratio of the second intermediate product to the macroporous adsorption resin is 1:4.

[0081] The other components and amounts are the same as in Example 1, and 7.4 kg of 1-C-(β-xylopyranosyl)-propanone is obtained according to the preparation method of Example 1.

[0082] Example 7

[0083] This example differs from Example 1 only in that the weight ratio of the second intermediate product to the macroporous adsorption resin is 1:1.

[0084] The other components and amounts are the same as in Example 1, and 7.1 kg of 1-C-(β-xylopyranosyl)-propanone is obtained according to the preparation method of Example 1.

[0085] Example 8

[0086] The difference between this example and Example 1 is that the macroporous adsorption resin is LX-T19, the specific surface area of LX-T19 is 580 m 2 / g, and the pore size of LX-T19 is 0.5 mm.

[0087] The other components and contents of this example are the same as those of Example 1, and 1-C-(β-xylopyranosyl)-propanone of 6.5 kg is obtained by the preparation method of Example 1.

[0088] Example 9

[0089] The difference between this example and Example 1 is that the macroporous adsorption resin is LX-66, the specific surface area of LX-66 is 570 m 2 / g, and the pore size of LX-66 is 1.0 mm.

[0090] The other components and contents of this example are the same as those of Example 1, and 1-C-(β-xylopyranosyl)-propanone of 6.7 kg is obtained by the preparation method of Example 1.

[0091] Example 10

[0092] The difference between this example and Example 1 is that ethanol is used as the solvent for crystallization.

[0093] The other components and contents of this example are the same as those of Example 1, and 1-C-(β-xylopyranosyl)-propanone of 7.1 kg is obtained by the preparation method of Example 1.

[0094] Example 11

[0095] The difference between this example and Example 1 is that acetonitrile is used as the solvent for crystallization.

[0096] The other components and contents of this example are the same as those of Example 1, and 1-C-(β-xylopyranosyl)-propanone of 7.0 kg is obtained by the preparation method of Example 1.

[0097] Example 12

[0098] The difference between this example and Example 1 is that the weight ratio of acetone and the mixed product of solid oil is 0.5:1.

[0099] The other components and contents of this example are the same as those of Example 1, and 1-C-(β-xylopyranosyl)-propanone of 7.7 kg is obtained by the preparation method of Example 1.

[0100] Example 13

[0101] This example is compared with Example 1, the only difference being that the weight ratio of acetone and solid oil mixed product is 2:1.

[0102] The other components and amounts are the same as in Example 1, and 1-C-(β-xylopyranosyl)-propanone, 5.9 kg, is obtained according to the preparation method of Example 1.

[0103] Comparative Example 1

[0104] This comparative example is compared with Example 1, the only difference being that no extraction purification is performed.

[0105] The other components and amounts are the same as in Example 1, and 1-C-(β-xylopyranosyl)-propanone, 5.4 kg, is obtained according to the preparation method of Example 1.

[0106] Comparative Example 2

[0107] This comparative example is compared with Example 1, the only difference being that no macroporous adsorption resin purification is performed.

[0108] Comparative Example 3

[0109] This comparative example is compared with Example 1, the only difference being that the weight ratio of the second intermediate product and macroporous adsorption resin is 1:0.5.

[0110] The other components and amounts are the same as in Example 1, and 1-C-(β-xylopyranosyl)-propanone, 6.9 kg, is obtained according to the preparation method of Example 1.

[0111] Comparative Example 4

[0112] This comparative example is compared with Example 1, the only difference being that the macroporous adsorption resin has a specific surface area of 270 m 2 / g and a pore size of 1.6 mm.

[0113] The other components and amounts are the same as in Example 1, and 1-C-(β-xylopyranosyl)-propanone, 4.1 kg, is obtained according to the preparation method of Example 1.

[0114] Comparative Example 5

[0115] This comparative example is compared with Example 1, the only difference being that the weight ratio of acetone and solid oil mixed product is 5:1.

[0116] The other components and amounts are the same as in Example 1, and 1-C-(β-xylopyranosyl)-propanone, 4.0 kg, is obtained according to the preparation method of Example 1.

[0117] Comparative Example 6

[0118] Comparative Example 1 was compared with Example 1, the only difference being that the weight ratio of acetone to solid oil mixture product was 0.1:1.

[0119] Test Example

[0120] 1. The 1-C-(β-xylopyranosyl)-propanone obtained in Example 1 was subjected to nuclear magnetic resonance hydrogen spectrum characterization using DMSO as solvent, and the results are shown in Figure 1. 6 The 1-C-(β-xylopyranosyl)-propanone obtained in Example 1 was subjected to nuclear magnetic resonance hydrogen spectrum characterization using DMSO as solvent, and the results are shown in Figure 1. Figure 1 Figure 1 Figure 1 is the nuclear magnetic resonance hydrogen spectrum of the 1-C-(β-xylopyranosyl)-propanone of Example 1, which proves that the product prepared in Example 1 is 1-C-(β-xylopyranosyl)-propanone.

[0121] 2. The purity and yield of the 1-C-(β-xylopyranosyl)-propanone prepared by different extraction times were studied. The 1-C-(β-xylopyranosyl)-propanone obtained in Examples 1-3 and Comparative Example 1 was subjected to HPLC analysis and detection, and the purity and yield of the 1-C-(β-xylopyranosyl)-propanone were obtained. The test results are shown in Table 1, and Table 1 is the purity and yield of Examples 1-3 and Comparative Example 1.

[0122] Table 1 Purity and yield of Examples 1-3 and Comparative Example 1

[0123]

[0124]

[0125] According to the results in Table 1, the purity of the 1-C-(β-xylopyranosyl)-propanone prepared in Comparative Example 1 without extraction purification is the lowest, because the acetylacetone not involved in the reaction and the small polar substances generated in the reaction are not removed. According to the results in Table 1, when the extraction times are less, the purity of the 1-C-(β-xylopyranosyl)-propanone is poor. With the increase of the extraction times, the purity of the 1-C-(β-xylopyranosyl)-propanone is improved, but the yield of the 1-C-(β-xylopyranosyl)-propanone of Example 3 extracted for 4 times is lower than that of the 1-C-(β-xylopyranosyl)-propanone of Example 1 extracted for 2 times. Therefore, the extraction times are preferably 2 times.

[0126] 3. The purity and yield of the 1-C-(β-xylopyranosyl)-propanone prepared by different extraction solvents were studied. The 1-C-(β-xylopyranosyl)-propanone obtained in Examples 1, 4-5 was subjected to HPLC analysis and detection, and the purity and yield of the 1-C-(β-xylopyranosyl)-propanone were obtained. The test results are shown in Table 2, and Table 2 is the purity and yield of Examples 1, 4-5.

[0127] ​Purity and yield of Example 1, Example 4-5 according to Table 2

[0128] Purity (%) Yield (%) Example 1 99.5 60.0 Example 4 99.4 49.7 Example 5 85.8 53.7

[0129] According to the results of Table 2, the impurity content of 1-C-(β-xylopyranosyl)-propanone as the n-hexane extractant is relatively high, the yield of 1-C-(β-xylopyranosyl)-propanone as the dichloromethane extractant is relatively low, and the yield and purity of 1-C-(β-xylopyranosyl)-propanone obtained by using ethyl acetate as the extractant at room temperature are both optimal.

[0130] 4, The purity and yield of 1-C-(β-xylopyranosyl)-propanone prepared without using the macroporous adsorption resin purification step were studied, and the 1-C-(β-xylopyranosyl)-propanone prepared by Example 1 and Comparative Example 2 was detected by HPLC analysis, and the purity and yield of 1-C-(β-xylopyranosyl)-propanone were obtained, and the test results are shown in Table 3, and Table 3 is the purity and yield of Example 1 and Comparative Example 2.

[0131] Table 3 Purity and yield of Example 1 and Comparative Example 2

[0132]

[0133] From the test data of Table 3, Comparative Example 2 without using macroporous adsorption resin for purification cannot obtain 1-C-(β-xylopyranosyl)-propanone by subsequent crystallization, which is because the macroporous adsorption resin purification can remove sugar substances and pigments, and avoid the problem that the high impurity concentration is not conducive to the precipitation of 1-C-(β-xylopyranosyl)-propanone.

[0134] 5, The purity and yield of 1-C-(β-xylopyranosyl)-propanone prepared by different weight ratios of the second intermediate product and macroporous adsorption resin were studied, and the 1-C-(β-xylopyranosyl)-propanone prepared by Example 1, Example 6-7 and Comparative Example 3 was detected by HPLC analysis, and the purity and yield of 1-C-(β-xylopyranosyl)-propanone were obtained, and the test results are shown in Table 4, and Table 4 is the purity and yield of Example 1, Example 6-7 and Comparative Example 3.

[0135] Table 4 Purity and yield of Example 1, Example 6-7 and Comparative Example 3

[0136] Purity (%) Yield (%) Example 1 99.5 60.0 Example 6 99.5 58.4 Example 7 87.6 56.0 Comparative Example 3 79.8 54.5

[0137] From the data of Table 4, the overloading adsorption of macroporous adsorption resin caused by too much loading of the second intermediate product affects the purity of the obtained 1-C-(β-xylopyranosyl)-propanone. Based on the analysis of Table 4, the weight ratio of the second intermediate product to macroporous adsorption resin is preferably 1:2.

[0138] 6. The purity and yield of 1-C-(β-pyranoxylosyl)-acetone prepared by different macroporous adsorption resins were studied. The 1-C-(β-pyranoxylosyl)-acetone prepared in Examples 1, 8-9 and Comparative Example 4 were analyzed by HPLC and the purity and yield of 1-C-(β-pyranoxylosyl)-acetone were obtained. The test results are shown in Table 5. Table 5 shows the purity and yield of Examples 1, 8-9 and Comparative Example 5.

[0139] Table 5. Purity and yield of Examples 1, 8-9 and Comparative Example 4

[0140] Purity (%) Yield (%) Example 1 99.5 60.0 Example 8 83.4 51.3 Example 9 81.7 52.9 Comparative Example 4 62.3 25.5

[0141] Table 5 shows that macroporous adsorption resins with different pore sizes and specific surface areas affect the yield and purity of 1-C-(β-xylanosyl)-acetone. This is because the pore size and specific surface area of ​​macroporous adsorption resins are key factors affecting their adsorption performance; the larger the specific surface area, the higher the adsorption capacity. Simultaneously, the pore size directly affects the free movement of molecules of different sizes. The combined effect of various factors leads to differences in the adsorption capacity of different macroporous adsorption resins. Table 5 shows that LX-835 in Example 1 exhibits the best adsorption performance.

[0142] 7. The purity and yield of 1-C-(β-xylanopyranosyl)-acetone prepared by different crystallization solvents were studied. The 1-C-(β-xylanopyranosyl)-acetone prepared in Examples 1 and 10-11 were analyzed by HPLC, and the purity and yield of 1-C-(β-xylanopyranosyl)-acetone were obtained. The test results are shown in Table 6. Table 6 shows the purity and yield of Examples 1 and 10-11.

[0143] Table 6. Purity and yield of Examples 1, 10-11

[0144] Purity (%) Yield (%) Example 1 99.5 60.0 Example 10 97.8 56.0 Example 11 98.0 55.3

[0145] The data in Table 6 show that the yield and purity of 1-C-(β-pyranoyl)-acetone using ethanol and acetonitrile as solvents are worse than those using acetone as solvent. Therefore, based on the analysis in Table 6, acetone is the preferred second organic solvent.

[0146] 8. The purity and yield of 1-C-(β-xylanopyranosyl)-acetone prepared by different weight ratios of crystallization solvent and solid-oil mixture were studied. The 1-C-(β-xylanopyranosyl)-acetone prepared in Examples 1, 12-13 and Comparative Examples 5-6 were analyzed by HPLC, and the purity and yield of 1-C-(β-xylanopyranosyl)-acetone were obtained. The test results are shown in Table 7. Table 7 shows the purity and yield of Examples 1, 12-13 and Comparative Examples 5-6.

[0147] Table 7 Purity and yield of Examples 1, 12-13 and Comparative Examples 5-6

[0148]

[0149] The data in Table 7 show that both excessively low and excessively high weight ratios of acetone to the solid-oil mixture will affect the yield and purity of 1-C-(β-xylanosyl)-acetone. The yield difference is relatively large because if too much acetone is added, a hot saturated solution cannot be formed, resulting in insufficient crystallization upon cooling and thus affecting the yield. If too little acetone is added, some of the substances to be crystallized will not dissolve during hot dissolution, which is not conducive to the precipitation of 1-C-(β-xylanosyl)-acetone.

[0150] By comparing the data from various embodiments and comparative examples, it can be seen that the steps in this invention are closely related. To maintain a unified whole, the substitution of any step or parameter will adversely affect the yield and purity of 1-C-(β-xylanopyranosyl)-acetone. Through the purification method of this invention, 1-C-(β-xylanopyranosyl)-acetone with a yield of 60% and a purity of 99.5% can be obtained.

[0151] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A process for the purification of 1-C-( β -xylopyranosyl)-propanone characterized in that, The method comprises the following steps: The xylose, acetylacetone and alkaline catalyst are mixed in a solvent to react, and 1-C-( β -xylopyranosyl)-propanone is synthesized. After the reaction is completed, the alkaline catalyst is removed by filtration to obtain a first intermediate product; wherein the alkaline catalyst is one or more than two of sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, lithium carbonate, sodium hydroxide, potassium hydroxide and lithium hydroxide.​ diluting the first intermediate product with a diluent, adding a first organic solvent to remove acetylacetone and small polar impurities in the first intermediate product by extraction, discarding the organic layer, and obtaining a second intermediate product; wherein the first organic solvent is one or more than two of ethyl acetate, petroleum ether, n-hexane, dichloromethane and chloroform; loading the second intermediate product on a macroporous adsorption resin, eluting the second intermediate product with an eluent, removing saccharide impurities and pigments in the second intermediate product, and obtaining an effluent; rotating and evaporating the effluent to obtain a solid-oil mixed product; cooling crystallization after mixing the solid oil mixture with a second organic solvent, precipitating the 1-C- β pyranosyl)-propanone, wherein the second organic solvent is one or two or more of acetone, halogenated hydrocarbon, alcohol, and acetonitrile.

2. The 1-C-( β - a method for purifying pyranosyl) -propanones, characterized by, the extraction is performed once to four times; the extraction is performed for 20 minutes to 30 minutes; the extraction is performed at a temperature of 20°C to 35°C.

3. The 1-C-( β - a method for purifying pyranosyl) -propanones, characterized by The weight ratio of the second intermediate product to the macroporous adsorption resin is 1: (1-4).

4. The 1-C-( β A method for purifying pyranosyl) -propanone characterized by, The macroporous adsorption resin has a specific surface area of 570 m 2 / g~700 m 2 / g; The pore size of the macroporous adsorption resin is 0.3mm-1.25mm.

5. The 1-C-( β A method for purifying pyranosyl) -propanone characterized in that, The loading flow rate is 250mL / min-350mL / min; The elution flow rate is 300mL / min-400mL / min.

6. The 1-C-( β - a method for purifying pyranosyl) -propanones, characterized by The weight ratio of the second organic solvent to the solid-oil mixed product is (0.5-2.0):

1.

7. The 1-C-( β - Purification method of pyranosyl)-propanone, characterized by, The cooling crystallization temperature is -10°C to 15°C; and the cooling crystallization time is 12h-24h.

8. The 1-C-( β A method for purifying pyranosyl) -propanone characterized in that, The eluent comprises one or both of water and ethanol; The macroporous adsorption resin comprises one or more than two of LX-T19, LX-66 and LX-835; The diluent comprises water; The weight ratio of the diluent to the xylose is (0.5-1.5):

1.

9. The 1-C-( β A method for purifying pyranosyl) -propanone characterized in that, After eluting the second intermediate product with the macroporous adsorption resin, the macroporous adsorption resin is further washed and regenerated with an aqueous ethanol solution with a volume concentration of 50%-95%.

10. The 1-C- ( 2 - Purification method of xylopyranosyl)-propanone, characterized by, The solvent comprises water; ​ The molar ratio of the xylose, the acetylacetone and the basic catalyst is 1.0: (1.0-1.5): (1.0-2.0); The reaction temperature is 90°C-100°C; and the reaction time is 5h-8h.

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