Method for simultaneously extracting 7-dehydrocholesterol and vitamin D3

Abstract

The invention relates to a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, which comprises the following steps: carrying out light conversion on a sample containing 7-dehydrocholesterol to obtain a light conversion solution; performing thermal conversion on the light conversion liquid to obtain thermal conversion liquid; concentrating the thermal conversion solution to obtain a concentrated solution, and stirring to obtain a first precipitate; mixing and dissolving the first precipitate and a first polar solvent, cooling to obtain a precipitate, namely 7-dehydrocholesterol, and drying supernate to obtain the vitamin D3. The sample containing the 7-dehydrocholesterol can be directly actinized without any treatment, the vitamin D3 can be obtained through saponification thermal conversion of the actinized reaction liquid, the vitamin D3 and the 7-dehydrocholesterol are jointly separated out through low-temperature crystallization and separated from other impurities, then the 7-dehydrocholesterol and the vitamin D3 are separated, and the 7-dehydrocholesterol and the vitamin D3 are separated. The purity and the yield of the two are greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical industry and relates to a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3. Background Art

[0002] 7-Dehydrocholesterol (7-DHC) is a 5,7-conjugated diene sterol and a precursor for cholesterol biosynthesis. Vitamin D3 (VD3), also known as cholecalciferol, is a type of vitamin D. When 7-dehydrocholesterol is exposed to ultraviolet B radiation, it can produce vitamin D3, hence the name provitamin D3. Traditionally, 7-DHC is prepared by isolating and extracting it from pigskin. Alternatively, crude wool esters can be used as raw materials, where cholesterol is produced through saponification. Cholesterol is then acylated, oxidized, hydrazonated, dehydrazonated, and saponified. Reports such as CN116790393A, CN116751698A, CN112813129A, CN116179384A, and CN115044603B focus on improvements and innovations in the fermentation technology for 7-DHC production using Saccharomyces cerevisiae. However, there are relatively few reports on the extraction and purification of 7-DHC from fermentation broths. CN115594727A discloses a method for extracting 7-DHC from fermentation broth, but this method uses supercritical extraction to extract and purify 7-DHC, which requires high equipment conditions. CN117362376A uses centrifugation, alkaline cell wall breaking, organic reagent extraction and crystallization to extract and purify 7-DHC from fermentation broth.

[0003] 7-DHC is a sterol that is insoluble in water, soluble in small amounts in chloroform, slightly soluble in DMSO, and slightly soluble in ethyl acetate. Therefore, conventional methods for extracting 7-dehydrocholesterol exploit its low solubility and employ organic solvent extraction and crystallization. However, the present invention discovered that 7-DHC in biosynthetic fermentation broth primarily exists as an ester. Furthermore, in addition to 7-DHC, some impurities are produced through similar metabolic pathways. Because these impurities have similar solubility to 7-DHC, solvent extraction and crystallization methods cannot yield high-purity 7-DHC.

[0004] Therefore, providing a method for extracting high-purity 7-DHC and obtaining high-purity vitamin D3 during the extraction process is an urgent problem to be solved in this field. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0008] (1) performing photoconversion on a sample containing 7-dehydrocholesterol to obtain a photoconversion solution;

[0009] (2) performing thermal conversion on the light-converted liquid to obtain a thermal conversion liquid;

[0010] (3) concentrating the thermal conversion liquid to obtain a concentrated liquid, stirring the concentrated liquid to obtain a first precipitate;

[0011] (4) mixing and dissolving the first precipitate with the first polar solvent, cooling the resulting precipitate to obtain 7-dehydrocholesterol, and drying the supernatant to obtain vitamin D3.

[0012] The present invention allows direct photochemical reaction of samples containing 7-dehydrocholesterol without any further treatment. The photochemical reaction liquid undergoes saponification and thermal conversion to produce vitamin D3. By controlling the 7-DHC conversion rate and combining it with low-temperature crystallization, the incompletely converted 7-DHC and vitamin D3 are precipitated as a "7-DHC-VD3" composition, which is then separated from other impurities. The composition is then resolved using a dissolution-recrystallization method, resulting in a 7-dehydrocholesterol content of 90% and a vitamin D3 content of over 80%.

[0013] Preferably, the conversion rate of 7-dehydrocholesterol in the photoconversion is 40-60%, for example, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 60%, etc. Other specific point values ​​within the above numerical range can be selected and will not be repeated here.

[0014] The conversion rate of 7-dehydrocholesterol is the conversion rate of 7-dehydrocholesterol into vitamin D3. When it is within the above-mentioned specific range, the yield and purity of the obtained product are higher.

[0015] Preferably, the wavelength of the light conversion is 275-300nm, for example, 275nm, 278nm, 280nm, 282nm, 285nm, 288nm, 290nm, 292nm, 295nm, 298nm, 300nm, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0016] Preferably, the sample containing 7-dehydrocholesterol includes yeast fermentation broth or 7-dehydrocholesterol solution.

[0017] Preferably, the weight percentage of solids in the yeast fermentation broth is 5-10%, for example, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, etc. Other specific values ​​within the above numerical range can be selected and will not be repeated here.

[0018] The solid includes bacterial cells, culture medium and the like.

[0019] Preferably, the yeast comprises any one of Saccharomyces cerevisiae, Pichia pastoris, Yarrowia lipolytica or Candida tropicalis, or a combination of at least two thereof.

[0020] Preferably, the temperature of the thermal conversion is 60-80° C., and the time is 4-6 hours.

[0021] The temperature can be selected as 60℃, 62℃, 65℃, 68℃, 70℃, 72℃, 75℃, 78℃, 80℃, etc. The time can be selected as 4h, 4.2h, 4.5h, 4.8h, 5h, 5.2h, 5.5h, 5.8h, 6h, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be listed here.

[0022] Preferably, the photoconversion liquid obtained after photoconversion of the yeast fermentation liquid is further mixed with an alkali during the thermal conversion.

[0023] Preferably, the base comprises sodium hydroxide.

[0024] Preferably, the amount of base added is 1-2% by mass of the yeast fermentation broth, for example, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, etc. Other specific values ​​within the above numerical range can be selected and will not be repeated here.

[0025] Preferably, the heat conversion liquid obtained after the yeast fermentation liquid is subjected to photoconversion and heat conversion is further mixed with the second polar solvent and separated 2-4 times, for example, 2 times, 3 times, 4 times, etc., before being concentrated.

[0026] Preferably, the mass ratio of the thermal conversion liquid to the second polar solvent in a single treatment is 1:(0.3-0.5), wherein the specific point values ​​in (0.3-0.5) can be selected from 0.3, 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, 0.46, 0.48, 0.5, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0027] Preferably, the temperature of mixing the thermal conversion liquid and the second polar solvent is 25-30° C. and the time is 0.5-1 h.

[0028] The temperature can be selected as 25℃, 25.5℃, 26℃, 26.5℃, 27℃, 27.5℃, 28℃, 28.5℃, 29℃, 29.5℃, 30℃, etc. The time can be selected as 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1h, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be listed here.

[0029] Preferably, the second polar solvent includes any one of n-hexane, petroleum ether, and pentane, or a combination of at least two thereof.

[0030] Preferably, the mass of the concentrated liquid is 5.5%-9% of the mass of the second polar solvent layer, for example, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, etc. Other specific point values ​​within the above numerical range can be selected and will not be repeated here.

[0031] The product of the thermal conversion liquid and the polar solvent mixture is combined and then concentrated. The mass of the concentrated liquid is 5.5-9% of the total mass of the second polar solvent layer after combination.

[0032] Preferably, the mass of the concentrated liquid is 5.5%-9% of the mass of the thermal conversion liquid, for example, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, etc. Other specific point values ​​within the above numerical range can be selected and will not be repeated here.

[0033] Preferably, the stirring temperature is -10 to -5°C and the stirring time is 2 to 4 hours.

[0034] The temperature can be selected as -10℃, -9.5℃, -9℃, -8.5℃, -8℃, -7.5℃, -7℃, -6.5℃, -6℃, -5.5℃, -5℃, etc. The time can be selected as 2h, 2.2h, 2.5h, 2.8h, 3h, 3.2h, 3.5h, 3.8h, 4h, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be listed here.

[0035] Preferably, the first polar solvent includes any one of methanol, ethanol, and isopropanol, or a combination of at least two of them.

[0036] Preferably, the mass ratio of the first polar solvent to the sample containing 7-dehydrocholesterol is (0.3-0.5):1, and the specific point values ​​in (0.3-0.5) can be selected from 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.45, 0.48, 0.5, etc. Other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0037] Preferably, the cooling temperature is 5-10℃, for example, 5℃, 5.5℃, 6℃, 6.5℃, 7℃, 7.5℃, 8℃, 8.5℃, 9℃, 9.5℃, 10℃, etc. Other specific point values ​​within the above numerical range can be selected, so they will not be repeated here.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) Samples containing 7-dehydrocholesterol can be directly photochemically treated without any treatment, and the photochemical reaction solution can be converted into VD3 through saponification heat.

[0040] (2) By controlling the conversion rate of 7-DHC and combining it with low-temperature crystallization, the incompletely converted 7-DHC and VD3 are precipitated in the form of a "7-DHC-VD3" composition, and then separated from other impurities.

[0041] (3) The composition is split by a dissolution-recrystallization method, and after splitting, the 7-dehydrocholesterol content can reach 90% and the VD3 content can reach more than 80%. DETAILED DESCRIPTION

[0042] In order to further illustrate the technical means and effects adopted by the present invention, the technical solutions of the present invention are further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0043] The calculation method of conversion rate in the following examples is as follows:

[0044]

[0045] The samples include yeast fermentation liquid and 7-DHC crystal dissolution liquid.

[0046] The yeast Saccharomyces cerevisiae used in the following examples is Saccharomyces cerevisiae S288C, the Pichia pastoris is Pichia pastoris X-33, and the Candida tropicalis is Candida tropicalis CICC 1798.

[0047] Example 1

[0048] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0049] (1) Photoconversion of a fermentation broth of Saccharomyces cerevisiae with a solid content of 8% was performed under irradiation with a 100W ultraviolet lamp at a wavelength of 280 nm, with the fermentation broth flow rate controlled at 5.0 mL / min and the 7-DHC conversion rate controlled at 50% to obtain a photoconversion broth;

[0050] (2) mixing the photoconversion liquid with sodium hydroxide, wherein the sodium hydroxide content is 1.5% of the mass of the saccharomyces cerevisiae fermentation liquid, and performing thermal conversion at a temperature of 70° C. for 5 h to obtain a thermal conversion liquid;

[0051] (3) The thermal conversion liquid was mixed with n-hexane at a mass ratio of 1:0.4 at 28°C for 0.8h, separated, and the mixing and separation were repeated three times. The n-hexane layers were combined and concentrated to obtain a concentrate. The mass of the concentrate was 6.7% of the mass of the combined n-hexane layers. The concentrate was stirred at -8°C and 200 rpm for 3h to obtain the first precipitate;

[0052] (4) The first precipitate is mixed and dissolved with methanol, with the mass ratio of methanol to fermentation liquid being 0.4:1, and the temperature is lowered to 8°C. The resulting precipitate is 7-dehydrocholesterol, and the solution is a vitamin D3 solution.

[0053] Example 2

[0054] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0055] (1) Pichia pastoris fermentation broth with a solid content of 5% was subjected to photoconversion under irradiation with a 100W ultraviolet lamp at a wavelength of 275 nm, with the fermentation broth flow rate controlled at 5.0 mL / min and the 7-DHC conversion rate controlled at 40%, to obtain a photoconversion broth;

[0056] (2) mixing the photoconversion liquid with sodium hydroxide, wherein the sodium hydroxide is 1% by mass of the Pichia pastoris fermentation liquid, and performing thermal conversion at a temperature of 80° C. for 4 h to obtain a thermal conversion liquid;

[0057] (3) The thermal conversion liquid and pentane were mixed at a mass ratio of 1:0.3 at 25°C for 0.5h, separated, and the mixing and separation were repeated three times. The pentane layers were combined and concentrated to obtain a concentrate. The mass of the concentrate was 6% of the mass of the combined pentane layers. The concentrate was stirred at -5°C and 200 rpm for 4h to obtain the first precipitate;

[0058] (4) The first precipitate is mixed and dissolved with methanol, with the mass ratio of methanol to fermentation liquid being 0.3:1, and the temperature is lowered to 10°C. The resulting precipitate is 7-dehydrocholesterol, and the solution is a vitamin D3 solution.

[0059] Example 3

[0060] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0061] (1) A Candida tropicalis fermentation broth with a solid content of 10% was subjected to photoconversion under irradiation with a 100W ultraviolet lamp at a wavelength of 300 nm, with the fermentation broth flow rate controlled at 5.0 mL / min and the 7-DHC conversion rate controlled at 60%, to obtain a photoconversion broth;

[0062] (2) mixing the photoconversion liquid with sodium hydroxide, wherein the sodium hydroxide is 2% by mass of the Candida tropicalis fermentation liquid, and performing thermal conversion at a temperature of 60° C. for 6 hours to obtain a thermal conversion liquid;

[0063] (3) The thermal conversion liquid and n-hexane were mixed at a mass ratio of 1:0.5 at 30°C for 0.8h, separated, and the mixing and separation were repeated three times. The n-hexane layers were combined and concentrated to obtain a concentrate. The mass of the concentrate was 5.5% of the mass of the combined n-hexane layers. The concentrate was stirred at -10°C and 200 rpm for 2h to obtain the first precipitate;

[0064] (4) The first precipitate is mixed and dissolved with methanol, with the mass ratio of methanol to fermentation liquid being 0.5:1, and the temperature is lowered to 5°C. The resulting precipitate is 7-dehydrocholesterol, and the solution is a vitamin D3 solution.

[0065] Example 4

[0066] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3. The only difference from Example 1 is that step (1) is "photoconversion of a fermentation broth of Saccharomyces cerevisiae with a solid content of 8% under irradiation with a 100W ultraviolet lamp at a wavelength of 280nm, controlling the fermentation broth flow rate to 5.0mL / min, and controlling the 7-DHC conversion rate to 70% to obtain a photoconversion liquid." The other operations remain unchanged.

[0067] Example 5

[0068] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3. The only difference from Example 1 is that step (1) is "photoconversion of a fermentation broth of Saccharomyces cerevisiae with a solid content of 8% under irradiation with a 100W ultraviolet lamp at a wavelength of 280nm, controlling the fermentation broth flow rate to 5.0mL / min and the 7-DHC conversion rate to 30% to obtain a photoconversion liquid." The other operations remain unchanged.

[0069] Example 6

[0070] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, which differs from Example 1 only in that step (3) is "mixing the thermal conversion liquid with n-hexane at a mass ratio of 1:0.4 at 28°C for 0.8h, separating the liquids, repeating the mixing and separation three times, combining and concentrating the n-hexane layers to obtain a concentrated liquid, the mass of which is 6.7% of the mass of the combined n-hexane layers, stirring at -20°C and 200 rpm for 3h to obtain a first precipitate", and the other operations remain unchanged.

[0071] Example 7

[0072] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, which differs from Example 1 only in that step (3) is "mixing the thermal conversion liquid with n-hexane at a mass ratio of 1:0.4 at 28°C for 0.8h, separating the liquids, repeating the mixing and separation three times, combining and concentrating the n-hexane layers to obtain a concentrated liquid, the mass of the concentrated liquid being 6.7% of the mass of the combined n-hexane layers, stirring at 0°C and 200 rpm for 3h to obtain a first precipitate", and the other operations remain unchanged.

[0073] Example 8

[0074] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0075] (1) lanolin-derived 7-DHC crystals were dissolved in n-hexane to form a solution with a solid content of 1%, and photoconversion was performed under irradiation with a 100W ultraviolet lamp at a wavelength of 275 nm. The flow rate of the solution was controlled at 5.0 mL / min, and the 7-DHC conversion rate was controlled at 50% to obtain a photoconversion solution;

[0076] (2) subjecting the photoconversion liquid to thermal conversion at a temperature of 80° C. for 4 h to obtain a thermal conversion liquid;

[0077] (3) Concentrating the thermal conversion solution to a concentration of 6% of the mass of the dissolved solution, stirring at -5°C and 200 rpm for 4 h to obtain a first precipitate;

[0078] (4) The first precipitate is mixed and dissolved with methanol, with the mass ratio of methanol to the dissolving solution being 0.3:1, and the temperature is lowered to 10°C. The resulting precipitate is 7-dehydrocholesterol, and the solution is a vitamin D3 solution.

[0079] Example 9

[0080] This embodiment provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0081] (1) Dissolving plant-derived 7-DHC crystals in n-hexane to form a solution with a solid content of 1%, and performing photoconversion under irradiation with a 100W ultraviolet lamp at a wavelength of 275 nm, controlling the flow rate of the solution to 5.0 mL / min and the 7-DHC conversion rate to 50%, to obtain a photoconversion solution;

[0082] (2) subjecting the photoconversion liquid to thermal conversion at a temperature of 80° C. for 4 h to obtain a thermal conversion liquid;

[0083] (3) Concentrating the thermal conversion solution to a concentration of 6% of the mass of the dissolved solution, stirring at -5°C and 200 rpm for 4 h to obtain a first precipitate;

[0084] (4) The first precipitate is mixed and dissolved with methanol, with the mass ratio of methanol to the dissolving solution being 0.3:1, and the temperature is lowered to 10°C. The resulting precipitate is 7-dehydrocholesterol, and the solution is a vitamin D3 solution.

[0085] Comparative Example 1

[0086] This comparative example provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0087] (1) Photoconversion of a fermentation broth of Saccharomyces cerevisiae with a solid content of 8% was performed under irradiation with a 100W ultraviolet lamp at a wavelength of 280 nm, with the fermentation broth flow rate controlled at 5.0 mL / min and the 7-DHC conversion rate controlled at 50% to obtain a photoconversion broth;

[0088] (2) mixing the photoconversion liquid with sodium hydroxide, wherein the sodium hydroxide content is 1.5% of the mass of the saccharomyces cerevisiae fermentation liquid, and performing thermal conversion at a temperature of 70° C. for 5 h to obtain a thermal conversion liquid;

[0089] (3) The thermal conversion liquid and n-hexane were mixed at a mass ratio of 1:0.4 at 28°C for 0.8h, and the mixture was separated. The mixing and separation were repeated three times. The n-hexane layers were combined, concentrated, and dried to obtain the product.

[0090] Comparative Example 2

[0091] This comparative example provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0092] (1) mixing a fermentation broth of Saccharomyces cerevisiae with a solid content of 8% with sodium hydroxide, wherein the amount of sodium hydroxide is 1.5% by mass of the fermentation broth, and performing thermal conversion at a temperature of 70° C. for 5 hours to obtain a thermal conversion liquid;

[0093] (2) The thermal conversion liquid and n-hexane were mixed at a mass ratio of 1:0.4 at 28°C for 0.8h, and the mixture was separated. The mixing and separation were repeated three times. The n-hexane layers were combined, concentrated, and dried to obtain the product.

[0094] Comparative Example 3

[0095] This comparative example provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, the method comprising:

[0096] (1) mixing a fermentation broth of Saccharomyces cerevisiae with a solid content of 8% with sodium hydroxide, wherein the amount of sodium hydroxide is 1.5% by mass of the fermentation broth, and performing thermal conversion at a temperature of 70° C. for 5 hours to obtain a thermal conversion liquid;

[0097] (2) The thermal conversion liquid and n-hexane were mixed at a mass ratio of 1:0.4 at 28°C for 0.8h, separated, and the mixing and separation were repeated three times. The n-hexane layers were combined and concentrated to obtain a concentrated solution. The mass of the concentrated solution was 6.7% of the mass of the n-hexane layer. The solution was stirred at -8°C and 200 rpm for 3h, and the precipitate was obtained.

[0098] Comparative Example 4

[0099] This comparative example provides a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, comprising: mixing a fermentation broth of brewer's yeast having a solid content of 8% with n-hexane at a mass ratio of 1:0.4 at 28° C. for 0.8 h, separating the liquids, repeating the mixing and separation three times, combining and concentrating the n-hexane layers to obtain a concentrated solution, and drying the solution.

[0100] Comparative Example 5

[0101] The separation method of this comparative example refers to Example 1 in CN114369047 A.

[0102] Test Example 1

[0103] Yield and purity test

[0104] The contents of 7-DHC and VD3 in the filter cake and fermentation broth were determined by liquid phase external standard method, and the contents were compared with the contents of 7-DHC and VD3 standards.

[0105] The specific parameters are:

[0106] Wavelength: 264 nm, chromatographic column: C18 column, mobile phase: methanol, flow rate: 0.7 mL / min

[0107]

[0108] Table 1

[0109]

[0110]

[0111] As shown in Table 1, the 7-dehydrocholesterol and vitamin D3 extracted by the method described herein have both high yields and high purity. Excessively high or low conversion rates of 7-dehydrocholesterol have a significant impact on yield. Excessively high or low temperatures during impurity removal also have an impact on both yield and purity.

[0112] The applicant declares that the present invention uses the above-mentioned embodiment to illustrate a method for simultaneously extracting 7-dehydrocholesterol and vitamin D3. However, the present invention is not limited to the above-mentioned embodiment, that is, it does not mean that the present invention must rely on the above-mentioned embodiment to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacement of various raw materials in the product of the present invention, addition of auxiliary ingredients, selection of specific methods, etc., are all within the scope of protection and disclosure of the present invention.

[0113] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0114] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A method for simultaneously extracting 7-dehydrocholesterol and vitamin D3, characterized in that: The method comprises: (1) performing photoconversion on a sample containing 7-dehydrocholesterol to obtain a photoconversion solution; (2) performing thermal conversion on the light-converted liquid to obtain a thermal conversion liquid; (3) concentrating the thermal conversion liquid to obtain a concentrated liquid, stirring the concentrated liquid to obtain a first precipitate; (4) mixing and dissolving the first precipitate with the first polar solvent, cooling the resulting precipitate to obtain 7-dehydrocholesterol, and drying the supernatant to obtain vitamin D3.

2. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to claim 1, wherein The conversion rate of 7-dehydrocholesterol in the photoconversion is 40-60%; Preferably, the wavelength of the light conversion is 275-300 nm.

3. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to claim 1 or 2, wherein: The sample containing 7-dehydrocholesterol includes yeast fermentation broth or 7-dehydrocholesterol solution; Preferably, the solid content in the yeast fermentation broth is 5-10% by weight; Preferably, the yeast comprises any one of Saccharomyces cerevisiae, Pichia pastoris, Yarrowia lipolytica or Candida tropicalis, or a combination of at least two thereof.

4. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to any one of claims 1 to 3, characterized in that The temperature of the thermal conversion is 60-80° C. and the time is 4-6 hours.

5. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to claim 3 or 4, characterized in that The photoconversion liquid obtained after the photoconversion of the yeast fermentation liquid is further mixed with alkali during the thermal conversion; Preferably, the base comprises sodium hydroxide; Preferably, the added amount of the alkali is 1-2% of the mass of the yeast fermentation broth.

6. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to any one of claims 3 to 5, characterized in that The heat conversion liquid obtained after the yeast fermentation liquid is subjected to light conversion and heat conversion is further mixed and separated with a second polar solvent 2-4 times before being concentrated; Preferably, the mass ratio of the thermal conversion liquid to the second polar solvent in a single treatment is 1:(0.3-0.5); Preferably, the temperature of the mixing of the thermal conversion liquid and the second polar solvent is 25-30° C. and the time is 0.5-1 h; Preferably, the second polar solvent includes any one of n-hexane, petroleum ether, and pentane, or a combination of at least two thereof; Preferably, the mass of the concentrated solution is 5.5%-9% of the mass of the second polar solvent layer; Preferably, the mass of the concentrated liquid is 5.5%-9% of the mass of the thermal conversion liquid.

7. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to any one of claims 1 to 6, characterized in that The stirring temperature is -10 to -5°C and the stirring time is 2 to 4 hours.

8. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to any one of claims 1 to 7, characterized in that The first polar solvent includes any one of methanol, ethanol, and isopropanol, or a combination of at least two of them.

9. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to any one of claims 1 to 8, characterized in that The mass ratio of the first polar solvent to the sample containing 7-dehydrocholesterol is (0.3-0.5):

1.

10. The method for simultaneously extracting 7-dehydrocholesterol and vitamin D3 according to any one of claims 1 to 9, characterized in that: The cooling temperature is 5-10℃.

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