5-aminolevulinic acid phosphate and preparation method thereof

Abstract

The invention relates to 5-aminolevulinic acid phosphate and a preparation method thereof, and belongs to the technical field of bioengineering. Comprising the following steps: carrying out membrane filtration on fermentation liquor containing 5-aminolevulinic acid, and removing thalli, proteins and macromolecular organic matters to obtain membrane filtration clear liquor; adding an organic extraction agent into the membrane filtration clear liquid, stirring, extracting under the condition that the pH value is 3.5-5, extracting the 5-aminolevulinic acid in the water phase into an organic phase, and separating and collecting the organic phase; and adding a phosphoric acid solution into the organic phase, performing back extraction under the conditions that the temperature is 30-35 DEG C and the pH value is 1-2, so that the 5-aminolevulinic acid in the organic phase is back-extracted into the water phase to obtain a 5-aminolevulinic acid phosphate solution, and sequentially performing decoloration, concentration and crystallization to obtain a finished product of the 5-aminolevulinic acid phosphate. According to the method, the 5-aminolevulinic acid phosphate is prepared by combining the organic extraction agent with phosphoric acid back extraction, the efficiency is high, and the extraction agent can be recycled.

Description

Technical Field

[0001] The invention belongs to the technical field of bioengineering, and particularly relates to 5-aminolevulinic acid phosphate and a preparation method thereof. Background Art

[0002] 5-Aminolevulinic acid (5-ALA) is a non-protein amino acid that is widely present in living organisms and is an essential precursor for the biosynthesis of tetrapyrrole compounds such as heme, chlorophyll, and vitamin B12. Due to the key metabolic nodes in the body and the important physiological functions of its downstream metabolites, 5-ALA has important application value and broad application prospects in medicine, health care, animal health, and plant nutrition. As a second-generation photosensitizer, 5-ALA has been used in photodynamic therapy of skin diseases and photodynamic diagnosis and auxiliary resection of cancer since the 1990s. 5-ALA is also used as a green and safe plant growth regulator to promote crop growth under adverse conditions and fruit coloring. Based on the important role of heme and vitamin B12 in animal energy and material metabolism, exogenous supplementation of 5-ALA can promote the metabolism of humans and livestock and poultry, and enhance the vitality and immunity of the body.

[0003] However, 5-ALA is unstable and easily degraded. Most of the 5-ALA on the market is in the form of 5-aminolevulinic acid hydrochloride. A large amount of concentrated hydrochloric acid is used in the preparation process. Concentrated hydrochloric acid is highly volatile and can corrode equipment and produce a pungent odor. As a result, in the prior art, the finished product of 5-aminolevulinic acid hydrochloride also has a certain pungent odor, which not only pollutes the environment, but also the residual chlorine element may cause certain harm to humans or livestock and poultry during later use. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a 5-aminolevulinic acid phosphate and a preparation method thereof, so as to solve one of the technical problems faced in the process of preparing 5-aminolevulinic acid hydrochloride in the prior art.

[0005] The purpose of the present invention is mainly achieved through the following technical solutions:

[0006] In one aspect, the present invention provides a method for preparing 5-aminolevulinic acid phosphate, comprising the following steps:

[0007] Step S1, performing membrane filtration on the fermentation broth containing 5-aminolevulinic acid to remove bacteria, proteins and macromolecular organic matter to obtain a membrane filtration clear liquid;

[0008] Step S2, adding an organic extractant to the membrane filtered clear liquid, stirring, extracting at a pH value of 3.5-5, extracting 5-aminolevulinic acid in the aqueous phase into the organic phase, and separating and collecting the organic phase;

[0009] Step S3, adding phosphoric acid solution to the organic phase, and performing back extraction at a temperature of 30-35° C. and a pH of 1-2 to back extract 5-aminolevulinic acid in the organic phase into the aqueous phase, reacting to obtain a 5-aminolevulinic acid phosphate solution, and sequentially decolorizing, concentrating, and crystallizing to obtain a 5-aminoacetic acid propionic acid phosphate product.

[0010] Furthermore, the membrane filtration in step S1 includes:

[0011] The fermentation liquid is filtered through a ceramic membrane to remove the bacteria, and the ceramic membrane clear liquid is collected; wherein the pore size of the ceramic membrane is 50-200nm, the operating pressure is 0.2-0.6MPa, the operating temperature is 25-35°C, and the operating pH value is 3.5-5;

[0012] The ceramic membrane clear liquid is filtered through an ultrafiltration membrane to remove proteins and macromolecular organic matter, and the ultrafiltration membrane clear liquid is collected; wherein, the pore size of the ultrafiltration membrane is 1000-10000Da, the operating pressure is 0.3-0.8MPa, the operating temperature is 25-35°C, and the operating pH value is 3.5-5.

[0013] Furthermore, in step S2, the organic extractant is a mixed solvent of di(2-ethylhexyl) phosphate and ethyl acetate; wherein, in the organic extractant, the volume ratio of di(2-ethylhexyl) phosphate to ethyl acetate added is 1:0.8-1.2.

[0014] Furthermore, in step S2, the amount of the organic extractant added is 0.2 to 1 times the volume of the membrane filtered clear liquid.

[0015] Furthermore, in step S3, the concentration of the phosphoric acid solution is 10 wt% to 20 wt%, and the amount of the phosphoric acid solution added is 0.5 to 1 times the volume of the organic phase.

[0016] Furthermore, in step S3, the decolorization comprises: adding 3-5% of the volume of the aqueous solution of activated carbon to the aqueous solution containing 5-aminolevulinic acid phosphate, decolorizing for 20-40 minutes, and filtering and collecting the decolorized solution.

[0017] Furthermore, in step S3, the concentration includes: concentrating the decolorized solution under the conditions of a vacuum degree of <-0.09 MPa and a temperature of 50-80° C. to a solid content of 40-60% to obtain a concentrated solution.

[0018] Furthermore, in step S3, the crystallization includes: adding 0.1-0.5% of the volume of the concentrated solution as seed crystals to the concentrated solution at a temperature of 40-50°C and a stirring rate of 50-200rpm, keeping the temperature for 1-2h, then cooling to 5-10°C at a rate of 3-5°C / h, filtering, washing with 2-4°C cold water, and drying to obtain the finished 5-aminoacetic acid propionic acid phosphate.

[0019] Furthermore, based on the volume of each liter of the fermentation liquid, the fermentation liquid includes 20 to 30 g / L of 5-aminolevulinic acid, and the remainder is bacteria, protein, macromolecular organic matter and water.

[0020] In a second aspect, the present invention further provides a 5-aminolevulinic acid phosphate prepared by the above-mentioned preparation method of 5-aminolevulinic acid phosphate, wherein the 5-aminolevulinic acid phosphate is a white crystal with uniform particles, and more than 90% of the particles are between 20-30 meshes.

[0021] Compared with the prior art, the present invention can achieve at least one of the following technical effects:

[0022] (1) The preparation method of 5-aminolevulinic acid phosphate provided by the present invention combines an organic extractant with phosphoric acid back extraction to prepare 5-aminolevulinic acid phosphate, which has high efficiency and the extractant can be reused. Compared with the prior art of using resin adsorption and analysis to prepare 5-ALA, the method has high yield, less time, less wastewater, no need for regenerated resin, and less investment; in addition, during the preparation process of 5-aminolevulinic acid phosphate, concentrated hydrochloric acid that is volatile and easy to corrode equipment is not used, which is friendly to the environment and personal safety; compared with 5-aminolevulinic acid hydrochloride, 5-aminolevulinic acid phosphate has lower solubility, and the same quality of fermentation broth can obtain more products, thereby reducing production costs. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] In the prior art, 5-ALA is mainly produced by microbial fermentation and chemical synthesis. The high complexity and high pollution of the chemical synthesis process limit the scale of its industrial production. The multi-step catalytic reaction and low product yield also further increase the production cost of the product, thereby limiting its large-scale application and promotion in various fields. The microbial fermentation method is a cheap method for producing 5-ALA, but the fermentation broth contains a large amount of sugars, proteins, amino acids, organic acids, metal ions and other compounds that affect the purification of 5-ALA. Therefore, the present invention provides a method for separating and purifying 5-ALA from a 5-ALA fermentation broth, and further using 5-ALA to prepare 5-aminolevulinic acid phosphate.

[0025] In one aspect, the present invention provides a method for preparing 5-aminolevulinic acid phosphate, comprising the following steps:

[0026] Step S1, performing membrane filtration on the fermentation broth containing 5-aminolevulinic acid to remove bacteria, proteins and macromolecular organic matter to obtain a membrane filtration clear liquid;

[0027] Step S2, adding an organic extractant to the membrane filtered clear liquid, stirring, extracting at a pH value of 3.5-5, extracting 5-aminolevulinic acid in the aqueous phase into the organic phase, and separating and collecting the organic phase;

[0028] Step S3, adding phosphoric acid solution to the organic phase, and performing back extraction at a temperature of 30-35° C. and a pH of 1-2 to back extract 5-aminolevulinic acid in the organic phase into the aqueous phase, reacting to obtain a 5-aminolevulinic acid phosphate solution, and sequentially decolorizing, concentrating, and crystallizing to obtain a 5-aminoacetic acid propionic acid phosphate product.

[0029] Specifically, the membrane filtration in step S1 includes ceramic membrane filtration and ultrafiltration membrane filtration arranged in sequence. Among them, the fermentation broth can remove the bacteria by ceramic membrane filtration, and the clear liquid of the ceramic membrane is collected and then enters the ultrafiltration membrane filtration to remove proteins and macromolecular organic matter. The purpose of membrane filtration is to reduce the emulsification phenomenon in the subsequent extraction process, which affects the extraction and separation effect. Among them, the pore size of the ceramic membrane is 50-200nm, the operating pressure is 0.2-0.6MPa, the operating temperature is 25-35℃, and the operating pH value is 3.5-5; the pore size of the ultrafiltration membrane is 1000-10000Da, the operating pressure is 0.3-0.8MPa, the operating temperature is 25-35℃, and the operating pH value is 3.5-5. It should be noted that the suitable pH values ​​of the ceramic membrane and ultrafiltration membrane used for membrane filtration in the embodiment of the present invention are both 3.5-5. Therefore, before membrane filtration, the pH value of the fermentation broth needs to be adjusted to, and glacial acetic acid is generally selected to adjust the pH value of the fermentation broth to 3.5-5 before membrane filtration.

[0030] Specifically, in step S2, the organic extractant is a mixed solvent of di(2-ethylhexyl) phosphate and ethyl acetate; wherein, in the organic extractant, the volume ratio of di(2-ethylhexyl) phosphate to the amount of ethyl acetate added is 1:0.8-1.2. For example, the volume ratio of di(2-ethylhexyl) phosphate to the amount of ethyl acetate added can be 1:0.8, 1:0.95, 1:1, 1:1.05 or 1:1.2, etc. Within this ratio range, the extraction yield of 5-ALA by the extractant is greater than 95%. In particular, when the volume ratio of di(2-ethylhexyl) phosphate to the amount of ethyl acetate added is 1:(0.95-1.05), the extraction yield of 5-ALA by the extractant can be as high as greater than 98%. The high extraction yield greatly improves the finished product yield of the 5-aminolevulinic acid phosphate finally obtained, and the finished product yield can reach more than 80%.

[0031] In addition, in step S2, the amount of the organic extractant added can be selected as 0.2 to 1 times the volume of the membrane filtration clear liquid. For example, the amount of the organic extractant added can be 0.2 times, 0.4 times, 0.6 times, 0.8 times or 1 times the volume of the membrane filtration clear liquid. The extraction condition is room temperature extraction, and the extraction process can be carried out at a stirring rate of 50 to 200 rpm. For example, the stirring rate can be selected as 50 rpm, 100 rpm, 150 rpm or 200 rpm, and the preferred stirring rate is 100 to 150 rpm. At this stirring rate, the organic extractant can more fully extract 5-ALA in the membrane filtration clear liquid. The extraction time can generally be controlled at 0.5h to 2h. For example, the extraction time can be selected as 0.5h, 1.0h, 1.5h or 2.0h. Through this step, 5-ALA in the aqueous phase (i.e., ultrafiltration membrane clear liquid) can be extracted into the organic phase.

[0032] It should also be noted that when using an organic extractant to extract the membrane filtration supernatant, the pH value of the membrane filtration supernatant needs to be maintained at 3.5-5. If necessary, glacial acetic acid can be used to adjust the pH value of the membrane filtration supernatant to 3.5-5, and then the organic extractant is added to the membrane filtration supernatant. The extraction is fully stirred at the above stirring rate to allow 5-ALA to be fully extracted into the organic extractant. Under this pH condition, 5-ALA can be stably present in the organic phase after extraction. The organic phase is collected for later use, and the aqueous phase can be treated for sewage discharge.

[0033] Specifically, in step S3, the concentration of the phosphoric acid solution is 10wt% to 20wt%, and the amount of the phosphoric acid solution added is 0.5 to 1 times the volume of the organic phase. Stirring is controlled to be 50-200rpm, the back extraction time is 0.5-2h, and the back extraction is performed at a temperature of 30 to 35°C and a pH value of 1 to 2, so that 5-ALA in the organic phase can be back extracted into the aqueous phase, and a 5-aminolevulinic acid phosphate solution is obtained by reaction, and the aqueous phase is separated and collected for standby use, and the organic phase can be recycled and repeated to step S2 for the next batch of extraction.

[0034] By adopting the above technical scheme, the organic phase containing 5-ALA is back-extracted by a phosphoric acid solution, 5-ALA is back-extracted into the phosphoric acid solution, and reacted with phosphoric acid to prepare 5-aminolevulinic acid phosphate. In the embodiment of the present invention, the phosphoric acid solution is used to replace the concentrated hydrochloric acid that is volatile and corrosive to equipment commonly used in the prior art during the preparation process. On the one hand, it is friendly to the environment and personal safety. On the other hand, under the above temperature and pH conditions, compared with the 5-aminolevulinic acid hydrochloride in the prior art, the solubility of 5-aminolevulinic acid phosphate is lower, and when the solubility of the product is low, it is easier to make the 5-aminolevulinic acid phosphate solution reach an oversaturated state, thereby prompting the excess solute 5-aminolevulinic acid phosphate to precipitate in a solid form, that is, more products can be generated, so the same quality of fermentation broth will obtain more 5-aminolevulinic acid phosphate products, reducing production costs.

[0035] Specifically, in step S3, the decolorization includes: adding 3-5% of the volume of the aqueous phase solution to the aqueous phase solution containing 5-aminolevulinic acid phosphate, decolorizing for 20-40 minutes, and filtering and collecting the decolorized liquid. It should be understood that the specific surface area of ​​the activated carbon in the embodiment of the present invention can be 800-1200㎡ / g.

[0036] Specifically, in step S3, the concentration includes: concentrating the decolorized solution under the conditions of a vacuum degree of <-0.09MPa and a temperature of 50-80°C, concentrating to a solid content of 40-60%, and obtaining a concentrated solution. For example, during concentration, the vacuum degree can be selected to be, and the temperature can be selected to be 50°C, 60°C, 70°C or 80°C, etc. The concentrated solid content can be selected to be 40%, 50% or 60%, etc. By concentrating under certain vacuum degree and temperature conditions, the solute concentration in the concentrated solution can be increased to promote subsequent crystallization, improve the crystallization yield, and improve the crystal purity.

[0037] Furthermore, in step S3, the crystallization comprises: adding 0.1-0.5% of the volume of the concentrated solution to the concentrated solution at a temperature of 40-50°C and a stirring rate of 50-200rpm, keeping the temperature for 1-2h, then cooling to 5-10°C at a rate of 3-5°C / h, filtering, washing with 2-4°C cold water, and drying to obtain the finished product of 5-aminoacetic acid propionic acid phosphate. By adopting the above technical scheme, under the above-mentioned heat preservation and crystallization conditions, in combination with the above-mentioned cooling rate and final crystallization temperature, the grain size and morphology can be controlled to a certain extent, the crystallization process is optimized, and the 5-aminoacetic acid propionic acid phosphate white crystal product with uniform particles and more than 90% of the particles between 20-30 meshes can be obtained.

[0038] Further, the fermentation liquid includes 20 to 30 g / L of 5-aminolevulinic acid per liter of the volume of the fermentation liquid, and the remainder is bacteria, protein, macromolecular organic matter and water. It should be understood that the fermentation liquid used in the embodiment of the present invention can be a fermentation liquid containing 5-aminolevulinic acid obtained by conventional fermentation in the prior art. For example, the conventional fermentation method can be referred to as follows: using Corynebacterium glutamicum as a fermentation strain and glycine as a substrate, a fermentation liquid containing 5-aminolevulinic acid can be obtained after adding an inducer. In addition, the content of bacteria, protein, macromolecular organic matter and water in the fermentation liquid can generally be referred to as follows: 200 to 300 g / L of bacteria, 20 to 40 g / L of protein, 20 to 50 g / L of macromolecular organic matter, and the remainder is water.

[0039] In a second aspect, the present invention further provides a 5-aminolevulinic acid phosphate prepared by the above-mentioned preparation method of 5-aminolevulinic acid phosphate, wherein the 5-aminolevulinic acid phosphate is a white crystal with uniform particles, and more than 90% of the particles are between 20-30 meshes.

[0040] 5-aminolevulinic acid phosphate and its preparation method are further described in detail below in conjunction with specific examples. These examples are only for comparison and explanation purposes, and the present invention is not limited to these examples.

[0041] Example 1

[0042] The method for preparing 5-aminolevulinic acid phosphate in the embodiment of the present invention comprises the following steps:

[0043] Step S1, taking 5L of fermentation broth containing 5-aminolevulinic acid, wherein the fermentation broth, based on the volume of each liter of fermentation broth, includes 21g / L of 5-aminolevulinic acid, 202g / L of bacteria, 21g / L of protein, 23g / L of macromolecular organic matter, and the remainder is water;

[0044] Step S2, filtering the fermentation liquid in step S1 with a ceramic membrane to remove the bacteria, and collecting the ceramic membrane clear liquid; wherein the pore size of the ceramic membrane is 50 nm, the operating pressure is 0.6 MPa, the operating temperature is 35° C., and the operating pH value is 3.5;

[0045] Step S3, filtering the ceramic membrane clear liquid in step S2 with an ultrafiltration membrane to remove proteins and macromolecular organic matter, and collecting the ultrafiltration membrane clear liquid; wherein the pore size of the ultrafiltration membrane is 1000Da, the operating pressure is 0.8MPa, the operating temperature is 35°C, and the operating pH value is 3.5;

[0046] Step S4, taking a mixed solvent of di(2-ethylhexyl) phosphate and ethyl acetate, wherein the volume ratio of di(2-ethylhexyl) phosphate to ethyl acetate is 1:0.8, adding 0.2 times the volume of the mixed solvent of the ultrafiltration membrane supernatant to the ultrafiltration membrane supernatant in step S3, performing sufficient extraction under the conditions of pH value of 3.5 and stirring rate of 50 rpm, the extraction time is 2 hours, so that 5-aminolevulinic acid in the aqueous phase is extracted into the organic phase, and the organic phase is separated and collected;

[0047] Step S5, adding a 10wt% phosphoric acid solution to the organic phase in step S4, wherein the amount of the phosphoric acid solution added is 1 times the volume of the organic phase, and performing back extraction under the conditions of a stirring rate of 200rpm, a temperature of 30°C, and a pH value of 2. The extraction time is 2h, so that the 5-aminolevulinic acid in the organic phase is back extracted into the aqueous phase to obtain a 5-aminolevulinic acid phosphate solution.

[0048] Step S6, adding 3% of the volume of the solution to the 5-aminolevulinic acid phosphate solution in step S5 for decolorization for 40 minutes, filtering, and collecting the decolorized solution;

[0049] Step S7, vacuum concentrating the decolorized liquid in step S6 at a vacuum degree of -0.09 MPa and a temperature of 50° C., concentrating the decolorized liquid to a solid content of 40% to obtain a concentrated liquid.

[0050] Step S8, when the concentrated solution in step S7 is heated to 40°C, stirring is controlled at 200 rpm, seed crystals accounting for 0.15% of the volume of the concentrated solution are added, the mixture is kept warm for 2 hours, and then the temperature is lowered to 10°C at a rate of 3°C / h, filtered, washed with 2°C cold water, and dried to obtain 140.5 g of 5-aminoacetic acid propionic acid phosphate product, with a yield of 80.4%.

[0051] Example 2

[0052] The method for preparing 5-aminolevulinic acid phosphate in the embodiment of the present invention comprises the following steps:

[0053] Step S1, taking 5L of fermentation broth containing 5-aminolevulinic acid, wherein the fermentation broth, based on the volume of each liter of fermentation broth, includes 25g / L of 5-aminolevulinic acid, 257g / L of bacteria, 28g / L of protein, 37g / L of macromolecular organic matter, and the remainder is water;

[0054] Step S2, filtering the fermentation liquid in step S1 with a ceramic membrane to remove the bacteria, and collecting the ceramic membrane clear liquid; wherein the pore size of the ceramic membrane is 100 nm, the operating pressure is 0.4 MPa, the operating temperature is 30° C., and the operating pH value is 4.0;

[0055] Step S3, filtering the ceramic membrane clear liquid in step S2 with an ultrafiltration membrane to remove proteins and macromolecular organic matter, and collecting the ultrafiltration membrane clear liquid; wherein the pore size of the ultrafiltration membrane is 5000Da, the operating pressure is 0.6MPa, the operating temperature is 30°C, and the operating pH value is 4.0;

[0056] Step S4, taking a mixed solvent of di(2-ethylhexyl) phosphate and ethyl acetate, wherein the volume ratio of di(2-ethylhexyl) phosphate to ethyl acetate is 1:1, adding 0.5 times the volume of the mixed solvent of the ultrafiltration membrane supernatant in step S3, performing sufficient extraction under the conditions of pH 4.0 and stirring rate of 150 rpm, the extraction time is 1 hour, so that 5-aminolevulinic acid in the aqueous phase is extracted into the organic phase, and the organic phase is separated and collected;

[0057] Step S5, adding a 15wt% phosphoric acid solution to the organic phase in step S4, wherein the amount of the phosphoric acid solution added is 0.7 times the volume of the organic phase, and performing back extraction under the conditions of a stirring rate of 150rpm, a temperature of 30°C, and a pH value of 1.5, and the extraction time is 1.0h, so that the 5-aminolevulinic acid in the organic phase is back extracted into the aqueous phase to obtain a 5-aminolevulinic acid phosphate solution.

[0058] Step S6, adding 4% of the volume of the solution to the 5-aminolevulinic acid phosphate solution in step S5 for decolorization for 30 minutes, filtering, and collecting the decolorized solution;

[0059] Step S7, vacuum concentrating the decolorized liquid in step S6 at a vacuum degree of -0.09 MPa and a temperature of 60° C., concentrating the decolorized liquid to a solid content of 50% to obtain a concentrated liquid.

[0060] Step S8, when the concentrated solution in step S7 is heated to 45°C, stirring is controlled at 150 rpm, seed crystals accounting for 0.3% of the volume of the concentrated solution are added, the mixture is kept warm for 1.5 hours, and then the temperature is lowered to 10°C at a rate of 4°C / h, filtered, washed with 3°C cold water, and dried to obtain 186.4 g of 5-aminoacetic acid propionic acid phosphate product, with a yield of 85.3%.

[0061] Example 3

[0062] The method for preparing 5-aminolevulinic acid phosphate in the embodiment of the present invention comprises the following steps:

[0063] Step S1, taking 5L of fermentation broth containing 5-aminolevulinic acid, wherein the fermentation broth, based on the volume of each liter of fermentation broth, includes 30g / L of 5-aminolevulinic acid, 297g / L of bacteria, 40g / L of protein, 51g / L of macromolecular organic matter, and the remainder is water;

[0064] Step S2, filtering the fermentation liquid in step S1 with a ceramic membrane to remove the bacteria, and collecting the ceramic membrane clear liquid; wherein the pore size of the ceramic membrane is 200 nm, the operating pressure is 0.2 MPa, the operating temperature is 25° C., and the operating pH value is 5;

[0065] Step S3, filtering the ceramic membrane clear liquid in step S2 with an ultrafiltration membrane to remove proteins and macromolecular organic matter, and collecting the ultrafiltration membrane clear liquid; wherein the pore size of the ultrafiltration membrane is 10000Da, the operating pressure is 0.3MPa, the operating temperature is 25°C, and the operating pH value is 5;

[0066] Step S4, taking a mixed solvent of di(2-ethylhexyl) phosphate and ethyl acetate, wherein the volume ratio of di(2-ethylhexyl) phosphate to ethyl acetate is 1:1.2, adding 1 times the volume of the mixed solvent to the ultrafiltration membrane supernatant in step S3, performing sufficient extraction under the conditions of pH 5 and stirring rate of 200 rpm, the extraction time is 0.5 h, so that 5-aminolevulinic acid in the aqueous phase is extracted into the organic phase, and the organic phase is separated and collected;

[0067] Step S5, adding a 20wt% phosphoric acid solution to the organic phase in step S4, wherein the amount of the phosphoric acid solution added is 0.5 times the volume of the organic phase, and performing back extraction under the conditions of a stirring rate of 50rpm, a temperature of 35°C, and a pH value of 1. The extraction time is 0.5h, so that the 5-aminolevulinic acid in the organic phase is back extracted into the aqueous phase to obtain a 5-aminolevulinic acid phosphate solution.

[0068] Step S6, adding 5% of the volume of activated carbon to the 5-aminolevulinic acid phosphate solution in step S5 for decolorization for 20 minutes, filtering, and collecting the decolorized solution;

[0069] Step S7, vacuum concentrating the decolorized liquid in step S6 at a vacuum degree of -0.09 MPa and a temperature of 80°C, concentrating the decolorized liquid to a solid content of 60% to obtain a concentrated liquid.

[0070] Step S8, when the concentrated solution in step S7 is heated to 50°C, stirring is controlled at 50 rpm, seed crystals accounting for 0.5% of the volume of the concentrated solution are added, the mixture is kept warm for 1 hour, and then the temperature is lowered to 5°C at a rate of 5°C / h, filtered, washed with 4°C cold water, and dried to obtain 214.5 g of 5-aminoacetic acid propionic acid phosphate product, with a yield of 81.8%.

[0071] Comparative Example 1

[0072] Compared with Example 2, the difference between Comparative Example 1 and Example 2 is that in step S5, the pH value of the stripping is set to 3.0, and other conditions remain unchanged. After testing, the prepared 5-ALA product is 80.7 g, and the yield is only 46.2%.

[0073] Comparative Example 2

[0074] Compared with Example 2, the difference between Comparative Example 2 and Example 2 is that in step S4, an equal amount of ethyl acetate is replaced by di(2-ethylhexyl) phosphate as an organic extractant, and other conditions remain unchanged. After testing, the prepared 5-ALA product is 24.3 g, and the yield is only 13.9%.

[0075] Comparative Example 3

[0076] Compared with Example 2, the difference between Comparative Example 3 and Example 2 is that in step S4, an equal amount of di(2-ethylhexyl) phosphate is replaced with ethyl acetate as an organic extractant, and other conditions remain unchanged. After testing, no extraction reaction occurs, and no 5-ALA finished product is obtained.

[0077] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing 5-aminolevulinic acid phosphate, characterized in that: The steps include: Step S1, performing membrane filtration on the fermentation broth containing 5-aminolevulinic acid to remove bacteria, proteins and macromolecular organic matter to obtain a membrane filtration clear liquid; Step S2, adding an organic extractant to the membrane filtered clear liquid, stirring, extracting at a pH value of 3.5-5, extracting 5-aminolevulinic acid in the aqueous phase into the organic phase, and separating and collecting the organic phase; Step S3, adding phosphoric acid solution to the organic phase, and performing back extraction at a temperature of 30-35° C. and a pH of 1-2 to back extract 5-aminolevulinic acid in the organic phase into the aqueous phase, reacting to obtain a 5-aminolevulinic acid phosphate solution, and sequentially decolorizing, concentrating, and crystallizing to obtain a 5-aminoacetic acid propionic acid phosphate product.

2. The method according to claim 1, characterized in that The membrane filtration in step S1 comprises: The fermentation liquid is filtered through a ceramic membrane to remove the bacteria, and the ceramic membrane clear liquid is collected; wherein the pore size of the ceramic membrane is 50-200nm, the operating pressure is 0.2-0.6MPa, the operating temperature is 25-35°C, and the operating pH value is 3.5-5; The ceramic membrane clear liquid is filtered through an ultrafiltration membrane to remove proteins and macromolecular organic matter, and the ultrafiltration membrane clear liquid is collected; wherein, the pore size of the ultrafiltration membrane is 1000-10000Da, the operating pressure is 0.3-0.8MPa, the operating temperature is 25-35°C, and the operating pH value is 3.5-5.

3. The method according to claim 1, characterized in that: In step S2, the organic extractant is a mixed solvent of di(2-ethylhexyl) phosphate and ethyl acetate; wherein the volume ratio of di(2-ethylhexyl) phosphate to ethyl acetate in the organic extractant is 1:0.8-1.

2.

4. The method according to claim 1 or 3, characterized in that: In the step S2, the amount of the organic extractant added is 0.2 to 1 times the volume of the membrane filtered clear liquid.

5. The method according to claim 1, characterized in that In the step S3, the concentration of the phosphoric acid solution is 10 wt% to 20 wt%, and the amount of the phosphoric acid solution added is 0.5 to 1 times the volume of the organic phase.

6. The method according to claim 1, characterized in that In the step S3, the decolorization comprises: Add 3-5% activated carbon of the volume of the aqueous phase solution to the aqueous phase solution containing 5-aminolevulinic acid phosphate, decolorize for 20-40 minutes, and collect the decolorized solution by filtration.

7. The method according to claim 1 or 6, characterized in that: In step S3, the concentration includes: The decolorized solution is concentrated under the conditions of vacuum degree <-0.09MPa and temperature of 50-80°C to a solid content of 40-60% to obtain a concentrated solution.

8. The method according to claim 7, characterized in that In the step S3, the crystallization comprises: The concentrated solution is added with 0.1-0.5% seed crystals by volume at a temperature of 40-50° C. and a stirring rate of 50-200 rpm, and the concentrated solution is kept warm for 1-2 hours to grow crystals, then cooled to 5-10° C. at a rate of 3-5° C. / h, filtered, washed with 2-4° C. cold water, and dried to obtain the finished 5-aminoacetic acid propionic acid phosphate.

9. The method according to claim 1, characterized in that: Calculated per liter of the fermentation liquid, the fermentation liquid includes 20 to 30 g / L of 5-aminolevulinic acid, and the remainder is bacteria, protein, macromolecular organic matter and water.

10. A 5-aminolevulinic acid phosphate, characterized in that The 5-aminolevulinic acid phosphate is prepared by the preparation method of any one of claims 1 to 9. The 5-aminolevulinic acid phosphate is white crystals with uniform particles, and more than 90% of the particles are between 20 and 30 meshes.