Reduced beta-nicotinamide mononucleotide disodium salt amorphous compound and preparation method thereof

Abstract

The invention relates to a reduced beta-nicotinamide mononucleotide disodium salt amorphous compound and a preparation method thereof, and belongs to the field of raw materials of health care products, cosmetics and food additives. The preparation method disclosed by the invention mainly comprises the following five main steps: adding a poor solvent into a reduced beta-nicotinamide mononucleotide disodium salt concentrated aqueous solution, adding a seed crystal, stirring to generate a precipitate, continuously dropwise adding the poor solvent to further separate out the precipitate, filtering and carrying out vacuum drying. The prepared reduced beta-nicotinamide mononucleotide disodium salt is an amorphous compound, the obtained amorphous compound does not contain crystal water, the water content is lower than 5%, and the amorphous compound can be stably stored for more than 3 months under the condition that the temperature is 20-30 DEG C and is isolated from air, and has the outstanding stability advantage.

Description

Technical Field

[0001] The invention belongs to the field of raw materials for health products, cosmetics and food additives, and specifically relates to a reduced β-nicotinamide mononucleotide disodium salt amorphous compound and a preparation method thereof. Background Art

[0002] Nicotinamide adenine dinucleotide (NAD+) is an important coenzyme required for more than 500 enzymatic reactions. An increasing number of studies have shown that increasing NAD+ equivalents can significantly improve multi-organ function, including liver function, kidney function, heart function, and skeletal muscle function. NAD+ can be synthesized using tryptophan in the de novo biosynthesis pathway, nicotinic acid (NA) in the preiss-handler pathway, and nicotinamide (NAM), nicotinamide riboside (NR), and nicotinamide mononucleotide (NMN) in the salvage pathway. In particular, as key NAD+ intermediates, NAM, NR, and NMN have been extensively studied for their potential therapeutic effects in many mouse disease models. Although increasing NAD+ levels by supplementing intermediates contributes to health and prolongs lifespan, their pharmacokinetics and metabolic fate in different organs under different disease conditions are still under investigation. In addition, it is unclear whether supplementing NAD+ precursors can prevent liver damage or liver fibrosis by maintaining redox homeostasis. Key NAD intermediates like NMN (often referred to as "NAD supplements") have attracted the attention of researchers, investors, and consumers for their significant effects related to disease and aging. Traditional NAD supplements such as NMN are oxidized NAD precursors. Studies have shown that a new reduced form of NAD precursor, reduced β-nicotinamide mononucleotide (NMNH), has better NAD-boosting effects than NMN and other biological functions such as increasing cellular antioxidant capacity, reducing fat accumulation, reducing inflammatory responses, and inhibiting tumor cell growth.

[0003] The synthesis process of reduced β-nicotinamide mononucleotide disodium salt (NMNH) is still in the laboratory research and development stage and cannot be industrialized. The main technical difficulties are: first, NMNH is the reduced form of NMN and is easily oxidized by air; second, the existing preparation methods mostly require freeze-vacuum drying to obtain amorphous solids, which has high production costs and cannot be industrialized. The NMNH products prepared by the existing technology have the problems of low purity, poor fluidity, easy moisture absorption and oily state, and rapid degradation. The freeze-drying process is usually accompanied by a certain degree of degradation, resulting in low purity of the obtained product, which cannot meet the product application requirements. Poor fluidity and easy moisture absorption make the product unable to be filled, tableted, or molded during preparation processing. The freeze-dried powder obtained by freeze-drying is needle-shaped, with a large specific surface area, and the contact surface with air and water increases, resulting in accelerated degradation. Therefore, it is of positive significance to develop new NMNH with good stability, good fluidity, and suitability for industrialization. Summary of the invention

[0004] In view of the problems raised in the background technology, the first purpose of the present invention is to provide a method for preparing reduced β-nicotinamide mononucleotide disodium salt, which has the characteristics of simple operation, high product purity, high yield, no need to use high-input and low-output equipment such as freeze-drying, and is easier to achieve industrialization. The second purpose of the present invention is to provide reduced β-nicotinamide mononucleotide disodium salt obtained by the preparation method of the present invention, which is an amorphous compound, has two characteristic glass transition temperatures in the temperature range of 63.69℃-74.67℃ and 85.52℃-131.99℃, and the peak values ​​of these two glass transition temperatures are 68.78℃ and 112.93℃ respectively; has a characteristic melting point temperature in the range of 217.21℃-241.88℃, and the peak value of the characteristic melting point temperature is 231.70℃. Raman spectrum shows that the amorphous compound has a Raman shift of 814cm -1 and 845cm -1 The reduced β-nicotinamide mononucleotide disodium salt amorphous compound has the advantages of high purity, less than 5% water content, high content of active ingredients, low hygroscopicity, and good formability. Compared with the crystalline reduced β-nicotinamide mononucleotide disodium salt, it has a lower water content and can be stably stored for more than 3 months at a temperature of 20℃-30℃, with outstanding stability advantages.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions: The method for preparing reduced β-nicotinamide mononucleotide disodium salt provided by the present invention comprises the following steps: (1) Using β-nicotinamide mononucleotide as a raw material, thiourea dioxide as a reducing agent, and pure water as a reaction solvent, the reduced β-nicotinamide mononucleotide aqueous solution is obtained by reaction under alkaline conditions; (2) separating and purifying the reduced β-nicotinamide mononucleotide aqueous solution using a high performance preparative liquid chromatography; (3) removing the ammonium salt with a strong acidic cation exchange resin, concentrating the solution through nanofiltration with a nanofiltration membrane, and adjusting the pH with a sodium hydroxide solution to obtain a concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt; (4) adding a poor solvent to the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt; (5) stirring and adding seed crystals; (6) Continuously stirring and producing suspended sediment; (7) Continue to add poor solvent to increase the yield; (8) Filter and dry to obtain the reduced β-nicotinamide mononucleotide disodium salt amorphous compound.

[0006] Furthermore, in step (1), a β-nicotinamide mononucleotide aqueous solution is first prepared, and a base is added to adjust the pH value to 9.5-10.0, and then thiourea dioxide is added to the solution to start the reaction. During the reaction process, the pH value of the reaction solution is maintained at 9.5-10.0.

[0007] Furthermore, the poor solvent in step (2) is ethanol, and in step (4), the temperature of the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt is 0° C.-25° C., and the poor solvent is ethanol.

[0008] Furthermore, the seed crystal is ribose or glucose or reduced β-nicotinamide mononucleotide disodium salt prepared using ribose or glucose as a precipitation primer.

[0009] Furthermore, the reduced β-nicotinamide mononucleotide disodium salt in the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt in step (4) has a mass percentage of 5%-15%.

[0010] Furthermore, the reaction temperature of step (1) is 39°C-44°C; and the drying temperature of step (8) is 20°C-35°C.

[0011] Furthermore, the amount of the poor solvent added in step (4) is 1.5-4.0 times the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt; and the amount of the poor solvent added in step (7) is 3.5-6.0 times the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt.

[0012] The present invention also provides the reduced β-nicotinamide mononucleotide disodium salt obtained by the above preparation method.

[0013] Further, the reduced β-nicotinamide mononucleotide disodium salt is an amorphous compound. When tested by differential scanning calorimeter, the temperature was increased from 10°C to 300°C at a heating rate of 10°C / min. The compound had two characteristic glass transition temperatures at 63.69°C-74.67°C and 85.52°C-131.99°C, and the peak values ​​of the two characteristic glass transition temperatures were 68.78°C and 112.93°C, respectively. The compound had a characteristic melting point temperature at 217.21°C-241.88°C, and the peak value of the characteristic melting point temperature was 231.70°C. The compound was scanned by laser confocal Raman spectrometer with an excitation wavelength of 532nm, a grating of 600 lines, an objective lens of 50 times, an integration time of 5s, and an accumulation number of 3 times. The test results showed that the compound had a Raman shift of 814cm -1 and 845cm -1 There are characteristic peaks.

[0014] The reduced β-nicotinamide mononucleotide disodium salt amorphous compound obtained by the preparation method of the present invention is used as a raw material for preparing health products, cosmetics and food additives.

[0015] Beneficial effects of the present invention: The invention can prepare the reduced β-nicotinamide mononucleotide disodium salt without using freeze-drying equipment, and the preparation method is simple to operate, low in cost, and more suitable for industrial production.

[0016] The reduced β-nicotinamide mononucleotide disodium salt prepared by the present invention is an amorphous compound: (1) detected by differential scanning calorimeter, the temperature is increased from 10°C to 300°C, the heating rate is 10°C / min, and it has two characteristic glass transition temperatures at 63.69°C-74.67°C and 85.52°C-131.99°C, and the peak values ​​of the two characteristic glass transition temperatures are 68.78°C and 112.93°C respectively; it has a characteristic melting point temperature at 217.21°C-241.88°C, and the peak value of the characteristic melting point temperature is 231.70°C; (2) scanned by laser confocal Raman spectrometer, the excitation wavelength is 532nm, the grating is 600 lines, the objective lens is 50 times, the integration time is 5s, the accumulation number is 3 times, the detection results show that at the Raman shift of 814cm -1 and 845cm -1 (3) It has a characteristic peak at the bottom; (3) It has good appearance and color, high purity, less than 5% water, high content of active ingredients, low hygroscopicity, and good formability. It can be stably stored at a temperature of 20℃-30℃ for more than 3 months. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is the XRPD pattern of the NMNH amorphous compound of Example 5 of the present invention; Figure 2is the H NMR spectrum of the NMNH amorphous compound of Example 5 of the present invention; Figure 3 is the mass spectrometer negative electrode mode spectrum of the NMNH amorphous compound of Example 5 of the present invention; Figure 4 is the mass spectrometry positive mode spectrum of the NMNH amorphous compound of Example 5 of the present invention; Figure 5 is a thermogravimetric analysis (TGA) spectrum of the NMNH amorphous compound of Example 5 of the present invention; Figure 6 is a thermogravimetric analysis (TGA) spectrum of the reduced β-nicotinamide mononucleotide disodium salt lyophilized powder of Example 2 of the present invention; Figure 7 is a differential scanning calorimetry (DSC) spectrum of the NMNH amorphous compound of Example 5 of the present invention; Figure 8 is a differential scanning calorimetry (DSC) spectrum of the reduced β-nicotinamide mononucleotide disodium salt lyophilized powder of Example 2 of the present invention; Fig. 9 is the Raman spectrum of the NMNH amorphous compound of Example 5 of the present invention; Fig.10 is the Raman spectrum of the reduced β-nicotinamide mononucleotide disodium salt lyophilized powder of Example 2 of the present invention; Fig.11 is the XRPD spectrum of the reduced β-nicotinamide mononucleotide disodium salt lyophilized powder of Example 2 of the present invention; Fig.12 It is the HPLC spectrum of the NMNH amorphous compound of Example 5 of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0019] A method for preparing reduced β-nicotinamide mononucleotide disodium salt comprises the following steps: (1) First, prepare a β-nicotinamide mononucleotide aqueous solution, add alkali to adjust the pH value to 9.5-10.0, then add thiourea dioxide to the solution to start the reaction. During the reaction, the pH value of the reaction solution is maintained at 9.5-10.0 to obtain a reduced β-nicotinamide mononucleotide aqueous solution.

[0020] (2) separating and purifying the reduced β-nicotinamide mononucleotide aqueous solution by high performance preparative liquid chromatography; (3) Use strong acid cation exchange resin to remove ammonium salts, (4) After nanofiltration and concentration through a nanofiltration membrane, the pH value is adjusted with a sodium hydroxide solution to obtain a concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt; (5) controlling the temperature of the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt to be 0°C-25°C and the mass percentage concentration to be 5%-15%, and adding ethanol, wherein the mass of ethanol added is 1.5-4.0 times of the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt; (6) stirring and adding seed crystals, wherein the seed crystals are ribose or glucose or reduced β-nicotinamide mononucleotide disodium salt prepared using ribose or glucose as a precipitation primer; (7) Continuously stirring and producing suspended sediment; (8) Continue to add poor solvent to improve the yield. The mass of the poor solvent added in Example 5 is 3.5-6.0 times the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt. (9) Filter and dry at 20°C-35°C to obtain the reduced β-nicotinamide mononucleotide disodium salt amorphous compound.

[0021] In order to more clearly illustrate the present invention, it is described in detail through the following examples.

[0022] Example 1 Preparation of lyophilized powder of reduced β-nicotinamide mononucleotide disodium salt (omitting the above step (3) and obtaining the product by lyophilization) Preparation of reduced β-nicotinamide mononucleotide disodium salt aqueous solution: Add 15L of pure water to a 50L glass reactor, heat to 40°C, add 1.52kg of nicotinamide mononucleotide (NMN) to the glass reactor, and adjust the pH to 9.5-10.0 with 10mol / L sodium hydroxide solution under stirring conditions to dissolve and clarify. Add 0.80kg of thiourea dioxide to the glass reactor, control the temperature at 39°C-44°C, and react for 5 hours under stirring. During the reaction, adjust the pH value with 10mol / L sodium hydroxide solution to control the pH to 9.0-10.0. After the reaction is completed, adjust the pH value to 10.5-11.0 with 10mol / L sodium hydroxide solution. Use a high performance preparative liquid chromatograph (chromatographic column diameter 15cm, column volume 6L, filler is polystyrene reverse phase filler, filler model is Unis P40-300, provided by Nanovita Technology Co., Ltd., the mobile phase is water and ethanol, the single loading volume of the reaction solution is 1.5L-2.0L, after loading, the product is eluted with pure water, and the fractions with a purity greater than 98.50% are collected in sections as qualified products to enter the next process step, and the fractions with a purity less than 98.50% are collected as unqualified products and incorporated into the reaction solution for purification again. Each purification takes 25-30 minutes. After 10 purifications, the reaction solution is eluted with 20% ethanol aqueous solution to remove impurities from the chromatographic column. After the chromatographic column is rinsed with pure water, the reaction solution can be loaded for purification. The reduced β-nicotinamide mononucleotide aqueous solution was purified and separated by nanofiltration (ultraviolet detector wavelength 340 nm); the reduced β-nicotinamide mononucleotide aqueous solution was concentrated to 14 L by nanofiltration membrane, and the pH value was adjusted with 10 mol / L sodium hydroxide solution during the nanofiltration concentration process to maintain the pH at 10.5-11.0 to obtain the reduced β-nicotinamide mononucleotide disodium salt concentrated aqueous solution, and the high performance liquid chromatography (C18 chromatographic column, detection wavelength 340 nm, external standard method detection, standard products purchased from Hubei Wei's Chemical Reagent Co., Ltd.) contained 1.66 kg of reduced β-nicotinamide mononucleotide disodium salt.

[0023] Preparation of freeze-dried powder: The concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt was loaded into a 2-square-meter vacuum freeze dryer for freeze drying, pre-frozen at -50℃ for 2h, and gradually heated to 30℃. After 72h, 1.69kg of amorphous pine needle-like light yellow powder was obtained, which was amorphous freeze-dried powder of reduced nicotinamide mononucleotide disodium salt, which was soft like cotton wool. The freeze-dried powder of reduced nicotinamide mononucleotide disodium salt remaining on the drying plate became viscous after being exposed to air for half an hour, and became oily after one hour. The drying loss of the 120℃ reduced nicotinamide mononucleotide disodium salt freeze-dried powder was 6.48%, and the sodium ion content was 11.05% detected by ion chromatography. The sodium ion content was calculated to be 11.81% after deducting water. The obtained freeze-dried powder had a pungent ammonia smell, and no free ammonium ions were detected by ion chromatography. It was speculated that the ammonium ions replaced part of the sodium ions and combined with NMNH to form salts.

[0024] Example 2 Preparation of lyophilized powder of reduced β-nicotinamide mononucleotide disodium salt (product obtained by lyophilization method) Preparation of reduced β-nicotinamide mononucleotide disodium salt aqueous solution: Add 15L of pure water to a 50L glass reactor, heat to 44°C, add 1.55kg of nicotinamide mononucleotide (NMN) to the glass reactor, adjust the pH to 9.5-10.0 with 10mol / L sodium hydroxide solution under stirring, and dissolve and clarify. Add 0.82kg of thiourea dioxide to the glass reactor, control the temperature at 39°C-44°C, and react for 6 hours under stirring. During the reaction, adjust the pH with 10mol / L sodium hydroxide solution to control the pH to 9.0-10.0. After the reaction is completed, adjust the pH to 10.5-11.0 with 10mol / L sodium hydroxide solution. Use a high-performance preparative liquid chromatograph (chromatographic column diameter 15cm, column volume 6L, filler is polystyrene reverse phase filler, filler model is Unis P40-300, provided by Nanovita Technology Co., Ltd., the mobile phase is water and ethanol, the single loading volume of the reaction solution is 1.5L-2.0L, after loading, the product is eluted with pure water, and the fractions with a purity greater than 98.50% are collected in sections as qualified products to enter the next process step, and the fractions with a purity lower than 98.50% are collected as unqualified products and incorporated into the reaction solution for purification again. Each purification takes 25-30 minutes. After 10 times of purification, the reaction solution is eluted with 20% ethanol aqueous solution. After the chromatographic column is rinsed with pure water, the reaction solution can be continued for sample loading and purification. The ultraviolet detector wavelength is 340nm) to purify and separate the reduced β-nicotinamide mononucleotide aqueous solution; the obtained reduced β-nicotinamide mononucleotide aqueous solution is passed through 001X7 strong acid cation exchange resin for ammonia removal purification operation (resin volume 6L Before purification, the reduced β-nicotinamide mononucleotide aqueous solution was treated with 0.5-1mol / L sodium hydroxide solution to form a sodium type, and then washed with purified water to pH 7-9 to load the reduced β-nicotinamide mononucleotide aqueous solution, and then eluted with pure water at a flow rate of 1-1.5 times the column volume / hour). After purification by 001X7 strong acid cation exchange resin, a reduced β-nicotinamide mononucleotide purified solution was obtained, and the reduced β-nicotinamide mononucleotide purified solution was concentrated to 16L by nanofiltration membrane. During the nanofiltration concentration process, the pH value was adjusted with 10mol / L sodium hydroxide solution to maintain the pH at 10.5-11.0 to obtain a concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt, and the high performance liquid chromatography detection (C18 chromatographic column, detection wavelength 340nm, external standard method detection, standard products purchased from Hubei Wei's Chemical Reagent Co., Ltd.) contained 1.68kg of reduced β-nicotinamide mononucleotide disodium salt.

[0025] Preparation of freeze-dried powder: The concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt was loaded into a 2-square-meter vacuum freeze dryer for freeze drying, pre-frozen at -50°C for 2 hours, and gradually heated to 30°C. After 72 hours, 1.71 kg of amorphous pine needle-like light yellow powder was obtained, which was amorphous freeze-dried powder of reduced nicotinamide mononucleotide disodium salt, which was soft like cotton wool. The freeze-dried powder of reduced nicotinamide mononucleotide disodium salt remaining on the drying plate became viscous after being exposed to air for half an hour, and became oily after one hour. The drying loss of the 120°C reduced nicotinamide mononucleotide disodium salt freeze-dried powder was 5.89%, and the purity was 99.18% as detected by high performance liquid chromatography (C18 column, mobile phase: water / methanol, detection wavelength 340nm). The sodium ion content detected by ion chromatograph was 11.41%, and the sodium ion content calculated after deducting water was 12.12%. The obtained freeze-dried powder has no pungent ammonia smell, and the sodium ion content is close to the theoretical content of disodium salt 12.11%. The thermogravimetric analysis spectrum of the obtained reduced β-nicotinamide mononucleotide disodium salt freeze-dried powder is shown in the attached figure. Figure 6 The differential calorimetry analysis spectrum is shown in the attached Figure 8 The Raman spectrum is shown in the attached Fig.10 The X-ray powder diffraction pattern is shown in the attached Fig.11 As shown, the X-ray powder diffraction pattern has obvious amorphous characteristic peaks, that is, there is no sharp absorption peak, and it is a diffuse type. The differential calorimetry analysis spectrum shows that the obtained freeze-dried powder has two characteristic glass transition temperatures in the temperature range of 50.92℃-56.94℃ and the temperature range of 80℃-110℃, and the peak values ​​of the two glass transition temperatures are 53.99℃ and 94.30℃, respectively. The obtained freeze-dried powder has a characteristic melting point temperature in the temperature range of 201.37℃-236.92℃, and further, the peak value of the characteristic melting point temperature is 224.36℃. The Raman spectrum of the obtained freeze-dried powder has a Raman shift (cm -1 )942cm -1 and 983cm -1 There is a stronger characteristic peak.

[0026] Example 3 Preparation of Reduced β-Nicotinamide Mononucleotide Disodium Salt Amorphous Compound (Omitting the above step (3) and obtaining the product by crystallization) Preparation of reduced β-nicotinamide mononucleotide disodium salt aqueous solution: Add 15L of pure water to a 50L glass reactor, heat to 39°C, add 1.49kg of nicotinamide mononucleotide (NMN) to the glass reactor, adjust the pH to 9.5-10.0 with 10mol / L sodium hydroxide solution under stirring, and dissolve and clarify. Add 0.78kg of thiourea dioxide to the glass reactor, control the temperature at 39°C-44°C, and react for 7h under stirring. During the reaction, adjust the pH with 10mol / L sodium hydroxide solution to control the pH to 9.5-10.5. After the reaction is completed, adjust the pH to 10.5-11.0 with 10mol / L sodium hydroxide solution. Use a high-performance preparative liquid chromatograph (chromatographic column diameter 15cm, column volume 6L, filler is polystyrene reverse phase filler, filler model is Unis P40-300, provided by Nanovita Technology Co., Ltd., the mobile phase is water and ethanol, the single loading volume of the reaction solution is 1.5L-2.0L, after loading, the product is eluted with pure water, and the fractions with a purity greater than 98.50% are collected in sections as qualified products to enter the next process step, and the fractions with a purity less than 98.50% are collected as unqualified products and incorporated into the reaction solution for purification again. Each purification takes 25-30 minutes. After 10 purifications, the reaction solution is eluted with 20% ethanol aqueous solution to remove impurities from the chromatographic column. After the chromatographic column is rinsed with pure water, the reaction solution can be loaded for purification. The reduced β-nicotinamide mononucleotide aqueous solution was purified and separated by nanofiltration (ultraviolet detector wavelength 340 nm); the reduced β-nicotinamide mononucleotide aqueous solution was concentrated to 12 L by nanofiltration membrane, and the pH value was adjusted with 10 mol / L sodium hydroxide solution during the nanofiltration concentration process to maintain the pH at 10.5-11.0 to obtain the reduced β-nicotinamide mononucleotide disodium salt concentrated aqueous solution, and the high performance liquid chromatography (C18 chromatographic column, detection wavelength 340 nm, external standard method detection, standard products purchased from Hubei Wei's Chemical Reagent Co., Ltd.) contained 1.52 kg of reduced β-nicotinamide mononucleotide disodium salt.

[0027] Preparation of amorphous compound of reduced β-nicotinamide mononucleotide disodium salt: Add the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt to a 50L glass reactor, add 24L ethanol at room temperature (20℃-25℃), continue stirring for 2h, and the solution remains clear. Under stirring, add 0.74kg xylose, continue stirring at room temperature (20℃-25℃) for 0.5h, the solution becomes clear, a layer of oil appears at the bottom, continue stirring at room temperature (20℃-25℃) for 2.5h, the oil at the bottom gradually increases, and no precipitation occurs. Under stirring, continue to add 12L ethanol dropwise at a rate of 3.0L / h. After the addition is completed, no precipitation occurs. Continue stirring at room temperature (20℃-25℃) for 2h, and a large amount of oil occurs at the bottom of the reactor, and no precipitation occurs. Under stirring, cool down to (10℃-15℃), stir for 2h, and no precipitation occurs. Under stirring, cool down to (0℃-5℃), stir for 2h, and no precipitation occurs. The preparation of reduced β-nicotinamide mononucleotide disodium salt amorphous compound failed.

[0028] Example 4 Preparation of Reduced β-Nicotinamide Mononucleotide Disodium Salt Amorphous Compound Preparation of reduced β-nicotinamide mononucleotide disodium salt aqueous solution: Add 30L of pure water to a 50L glass reactor, heat to 42°C, add 3.12kg of nicotinamide mononucleotide (NMN) to the glass reactor, adjust the pH to 9.5-10.5 with 10mol / L sodium hydroxide solution under stirring, and dissolve and clarify. Add 1.72kg of thiourea dioxide to the glass reactor, control the temperature at 39°C-44°C, and react for 7h under stirring. During the reaction, adjust the pH with 10mol / L sodium hydroxide solution to control the pH to 9.5-10.5. After the reaction is completed, adjust the pH to 10.5-11.0 with 10mol / L sodium hydroxide solution. Use a high-performance preparative liquid chromatograph (chromatographic column diameter 15cm, column volume 6L, filler is polystyrene reverse phase filler, filler model is Unis P40-300, provided by Nanovita Technology Co., Ltd., the mobile phase is water and ethanol, the single loading volume of the reaction solution is 1.5L-2.0L, after loading, the product is eluted with pure water, and the fractions with a purity greater than 98.50% are collected in sections as qualified products to enter the next process step, and the fractions with a purity less than 98.50% are collected as unqualified products and incorporated into the reaction solution for purification again. Each purification takes 25-30 minutes. After 10 times of purification, the reaction solution is eluted with 20% ethanol aqueous solution. After the chromatographic column is rinsed with pure water, the reaction solution can be continued to be loaded and purified. The ultraviolet detector wavelength is 340nm) to purify and separate the reduced β-nicotinamide mononucleotide aqueous solution; the obtained reduced β-nicotinamide mononucleotide aqueous solution is passed through 001X7 strong acid cation exchange resin for ammonia removal purification operation (resin volume 12 The purified β-nicotinamide mononucleotide solution was washed with purified water to pH 7-9, and the reduced β-nicotinamide mononucleotide aqueous solution was loaded, and then eluted with pure water at a flow rate of 1-1.5 times the column volume / hour). The purified β-nicotinamide mononucleotide solution was purified by 001X7 strong acid cation exchange resin to remove ammonia and obtain a purified β-nicotinamide mononucleotide solution. The solution was concentrated to 36 L by nanofiltration with a nanofiltration membrane. During the nanofiltration concentration process, the pH value was adjusted with a 10 mol / L sodium hydroxide solution to maintain the pH at 10.5-11.0 to obtain a concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt. The solution was detected by high performance liquid chromatography (C18 column, detection wavelength 340 nm, external standard method, and the standard product was purchased from Hubei Wei's Chemical Reagent Co., Ltd.). The solution contained 3.24 kg of reduced β-nicotinamide mononucleotide disodium salt.

[0029] Preparation of amorphous compound of reduced β-nicotinamide mononucleotide disodium salt: Take 6L of concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt obtained in the previous step (high performance liquid chromatography detected 0.53kg of reduced β-nicotinamide mononucleotide disodium salt) and add it to a 50L glass reactor. Add 12L of ethanol at room temperature (20℃-25℃) and continue stirring for 2h. The solution is still clear. Under stirring conditions, add 0.74kg of xylose and continue stirring at room temperature (20℃-25℃) for 0.5h. The solution is clear, and a layer of oil appears at the bottom. The oil at the bottom is gradually converted into powder and precipitated. There is a precipitate suspended in the solution. Continue stirring at room temperature (20℃-25℃) for 2.5h, a large amount of precipitate is precipitated, the solution is turbid, and some precipitates are agglomerated in blocks. Under stirring conditions, continue to drop 12L of ethanol at a rate of 3.0L / h. After the addition is completed, continue stirring at room temperature (20℃-25℃) for 2h. The high performance liquid chromatography detected that the supernatant of the crystallization mother liquor contained 0.24kg of reduced β-nicotinamide mononucleotide disodium salt. Under stirring conditions, continue to drop 12L of ethanol at a rate of 3.0L / h. After the addition is completed, continue stirring at room temperature (20℃-25℃) for 2h. The high performance liquid chromatography detected that the supernatant of the crystallization mother liquor contained 0.12kg of reduced β-nicotinamide mononucleotide disodium salt. Under stirring conditions, continue to drop 6L of ethanol at a rate of 3.0L / h. After the addition is completed, continue stirring at room temperature (20℃-25℃) for 2h. The high performance liquid chromatography detected that the supernatant of the crystallization mother liquor contained 0.068kg of reduced β-nicotinamide mononucleotide disodium salt. The material was discharged, filtered, and the filter cake was washed with 5L ethanol and vacuum dried in a vacuum drying oven at 30°C for 15h to obtain 0.45kg of off-white dry solid powder. The reduced nicotinamide mononucleotide disodium salt freeze-dried powder remaining on the drying plate was still in powder form after being exposed to the air for half an hour, and was still in powder form after one hour, without irritating ammonia smell. Compared with the reduced β-nicotinamide mononucleotide disodium salt freeze-dried powder prepared in Example 2, it has better fluidity and appearance color. The drying loss at 120°C was 2.59%, and the purity was 98.89% as detected by high performance liquid chromatography (C18 chromatographic column, mobile phase: water / methanol, detection wavelength 340nm). The sodium ion content detected by ion chromatograph was 11.77%, and the sodium ion content was calculated to be 12.08% after deducting water. The obtained freeze-dried powder had no pungent ammonia smell, and the sodium ion content was close to the theoretical content of disodium salt 12.11%, that is, the obtained off-white dry solid powder was an amorphous compound of reduced β-nicotinamide mononucleotide disodium salt.

[0030] Example 5 Preparation of Reduced β-Nicotinamide Mononucleotide Disodium Salt Amorphous Compound Preparation of reduced β-nicotinamide mononucleotide disodium salt amorphous compound: Take 6L of the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt obtained in Example 4 (high performance liquid chromatography detected that it contained 0.54kg of reduced β-nicotinamide mononucleotide disodium salt) and add it to a 50L glass reactor. Add 12L of ethanol at room temperature (20°C-25°C) and continue stirring for 2h. The solution is still clear. Under stirring conditions, add 0.02kg of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound obtained in Example 4, continue stirring at room temperature (20°C-25°C) for 0.5h, and a precipitate is suspended in the solution. Continue stirring at room temperature (20°C-25°C) for 2.5h, a large amount of precipitate is precipitated, the solution is turbid, and there is no agglomeration phenomenon. Under stirring conditions, the temperature was lowered (10℃-15℃), and 12L of ethanol was continued to be added dropwise at a rate of 4.0L / h. After the addition was completed, stirring was continued at low temperature (10℃-15℃) for 2h. The HPLC detected that the supernatant of the crystallization mother liquor had a residual reduced β-nicotinamide mononucleotide disodium salt of 0.18kg. Under stirring conditions at low temperature (10℃-15℃), 12L of ethanol was continued to be added dropwise at a rate of 4.0L / h. After the addition was completed, stirring was continued at low temperature (10℃-15℃) for 2h. The HPLC detected that the supernatant of the crystallization mother liquor had a residual reduced β-nicotinamide mononucleotide disodium salt of 0.086kg. Under stirring conditions at low temperature (10℃-15℃), 6L of ethanol was continued to be added dropwise at a rate of 4.0L / h. After the addition was completed, stirring was continued at low temperature (10℃-15℃) for 2h. The HPLC detected that the supernatant of the crystallization mother liquor had a residual reduced β-nicotinamide mononucleotide disodium salt of 0.044kg. Discharge, filter, wash the filter cake with 5L ethanol, and use a vacuum drying oven at 25°C for 24h to obtain 0.48kg of off-white dry solid powder. The lyophilized powder of reduced nicotinamide mononucleotide disodium salt remaining on the drying plate is still in powder state after being exposed to the air for half an hour, and is still in powder state after one hour, without irritating ammonia smell. Compared with the amorphous compound of reduced β-nicotinamide mononucleotide disodium salt prepared in Example 4, the fluidity and appearance color are consistent, and there is no agglomeration phenomenon. The drying loss at 120°C is 3.70%, and the purity is 99.53% detected by high performance liquid chromatography (C18 chromatographic column, mobile phase: water / methanol, detection wavelength 340nm). Compared with Example 4, the obtained solid powder has significantly improved purity and significantly improved yield. The sodium ion content detected by ion chromatograph is 11.66%, and the sodium ion content calculated after deducting water is 12.11%. The obtained freeze-dried powder has no pungent ammonia smell, and the sodium ion content meets the standard of 12.11% of the theoretical content of disodium salt, that is, the obtained off-white dry solid powder is a reduced β-nicotinamide mononucleotide disodium salt amorphous compound. The obtained reduced β-nicotinamide mononucleotide disodium salt amorphous compound X powder diffraction spectrum is as shown in the attached Figure 1As shown, the X-ray powder diffraction spectrum has obvious amorphous characteristic peaks, that is, there is no sharp absorption peak, which is a diffuse type, proving that the obtained solid is an amorphous compound of reduced β-nicotinamide mononucleotide disodium salt. Figure 2 The mass spectrometer negative mode spectrum is shown in the attached Figure 3 The mass spectrometry positive mode spectrum is shown in the attached Figure 4 Thermogravimetric analysis spectra are shown in the attached Figure 5 The differential calorimetry analysis spectrum is shown in the attached Figure 7 The Raman spectrum is shown in the attached Fig. 9 As shown, the HPLC chromatogram of high performance liquid chromatography detection is shown in the attached Fig.12 As shown. The obtained reduced β-nicotinamide mononucleotide disodium salt amorphous compound is characterized in that the differential calorimetry spectrum of the amorphous compound has two characteristic glass transition temperatures in the temperature range of 63.69°C-74.67°C and the temperature range of 85.52°C-131.99°C. Furthermore, the peak values ​​of the two glass transition temperatures are 68.78°C and 112.93°C, respectively. The obtained amorphous compound has a characteristic melting point temperature in the temperature range of 217.21°C-241.88°C, and the peak value of the characteristic melting point temperature is 231.70°C. The Raman spectrum of the obtained amorphous compound has a Raman shift (cm -1 )814cm -1 and 845cm -1 There is a stronger characteristic peak.

[0031] Example 6 Preparation of Reduced β-Nicotinamide Mononucleotide Disodium Salt Amorphous Compound Preparation of reduced β-nicotinamide mononucleotide disodium salt amorphous compound: Take 6L of the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt obtained in Example 4 (high performance liquid chromatography detected that it contained 0.52kg of reduced β-nicotinamide mononucleotide disodium salt) and add it to a 50L glass reactor. Add 12L of ethanol at room temperature (20°C-25°C) and continue stirring for 2h. The solution is still clear. Under stirring conditions, add 0.02kg of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound obtained in Example 5, continue stirring at room temperature (20°C-25°C) for 0.5h, and a precipitate is suspended in the solution. Continue stirring at room temperature (20°C-25°C) for 2.5h, a large amount of precipitate is precipitated, the solution is turbid, and there is no agglomeration phenomenon. Under stirring conditions, the temperature was lowered (0℃-5℃), and 12L of ethanol was continued to be added dropwise at a rate of 6.0L / h. After the addition was completed, stirring was continued at low temperature (0℃-5℃) for 2h. The HPLC detected that the supernatant of the crystallization mother liquor had a residual reduced β-nicotinamide mononucleotide disodium salt of 0.14kg. Under stirring conditions at low temperature (0℃-5℃), 12L of ethanol was continued to be added dropwise at a rate of 6.0L / h. After the addition was completed, stirring was continued at low temperature (0℃-5℃) for 2h. The HPLC detected that the supernatant of the crystallization mother liquor had a residual reduced β-nicotinamide mononucleotide disodium salt of 0.0686kg. Under stirring conditions at low temperature (10℃-15℃), 6L of ethanol was continued to be added dropwise at a rate of 6.0L / h. After the addition was completed, stirring was continued at low temperature (0℃-5℃) for 2h. The HPLC detected that the supernatant of the crystallization mother liquor had a residual reduced β-nicotinamide mononucleotide disodium salt of 0.035kg. Discharge, filter, wash the filter cake with 5L ethanol, and use a vacuum drying oven at 25°C for 24h to obtain 0.49kg of off-white dry solid powder. The lyophilized powder of reduced nicotinamide mononucleotide disodium salt remaining on the drying plate is still in powder state after being exposed to the air for half an hour, and is still in powder state after one hour, without irritating ammonia smell. Compared with the amorphous compound of reduced β-nicotinamide mononucleotide disodium salt prepared in Example 5, the fluidity and appearance color are consistent, and there is no agglomeration phenomenon. The drying loss at 120°C is 3.58%, and the purity is 99.44% detected by high performance liquid chromatography (C18 chromatographic column, mobile phase: water / methanol, detection wavelength 340nm). Compared with Example 5, the obtained solid powder has a decreased purity and an increased yield. The sodium ion content detected by ion chromatograph is 11.67%, and the sodium ion content calculated after deducting water is 12.10%. The obtained freeze-dried powder has no pungent ammonia smell, and the sodium ion content meets the standard of 12.11% of the theoretical content of disodium salt, that is, the obtained off-white dry solid powder is a reduced β-nicotinamide mononucleotide disodium salt amorphous compound.

[0032] Note: In all embodiments of the present invention, unless otherwise specified, the ethanol and poor solvent referred to herein refer to 95% ethanol.

[0033] Product performance analysis of each embodiment: Detection of reduced β-nicotinamide mononucleotide disodium salt obtained in Examples 1 to 6: The theoretical value of the sodium ion content of the reduced β-nicotinamide mononucleotide disodium salt is 12.105%, the molecular weight is 380, and the molecular weight in the sodium-free state is 336. The sodium ion content of the solids obtained in Examples 1 to 6 was tested respectively (see each example for details). The results show that the sodium ion content of the products obtained in Examples 1 to 6, except for Example 1, is between 12.08% and 12.12% after deducting the moisture content of the solid powder (the sodium ion content in Example 1 is significantly different from the theoretical value due to residual ammonia), which is consistent with the characterization of the reduced β-nicotinamide mononucleotide disodium salt. Furthermore, the solid obtained in Example 5 was subjected to nuclear magnetic resonance and hydrogen spectrum detection, and high-resolution positive and negative mass spectrometry detection (XRPD spectrum is attached as shown in the figure). Figure 1 The hydrogen spectrum is shown in the attached Figure 2 The mass spectrometer negative mode is shown in the attached Figure 3 As shown, the mass spectrometer positive mode Figure 4 As shown), the molecular ion peak of the obtained solid high-resolution mass spectrometry positive mode is M+: 381.0305, which is consistent with the molecular weight of the reduced β-nicotinamide mononucleotide disodium salt, and the molecular ion peak of the obtained solid high-resolution mass spectrometry negative mode is M-: 335.0684, which is consistent with the molecular weight of the reduced β-nicotinamide mononucleotide disodium salt in the sodium-free state of 336, proving that the obtained solid is the reduced β-nicotinamide mononucleotide disodium salt, and the structural formula is as follows:

[0034] In the purification process of Example 1 and Example 2, after adding step (3), the residual ammonia odor in the product is effectively removed, avoiding the health and safety risks that may arise during the application of the product.

[0035] In the crystallization process of Examples 4 to 6, after adding the poor solvent and stirring for 2 hours, the solution is still clear, indicating that it is difficult to precipitate the reduced β-nicotinamide mononucleotide disodium salt without adding seed crystals. After adding the seed crystals, the temperature is maintained and stirred for a certain period of time to start precipitation. After the precipitation, the poor solvent is continued to be added dropwise, and the reduced β-nicotinamide mononucleotide disodium salt continues to precipitate, and the product yield is continuously improved. At the same time, in the stage of adding the poor solvent, different temperatures have a significant effect on the product yield and product purity. From the results of Examples 4 to 6, it can be seen that the most suitable temperature range is 10°C-15°C, which not only ensures a higher yield, but also obtains the highest product purity, which is more conducive to industrial production.

[0036] By comparing the product purity, fluidity, hygroscopicity and room temperature stability (as shown in the stability test below) of Example 5 and Example 2, the reduced β-nicotinamide mononucleotide disodium salt amorphous compound obtained in Example 5 has higher purity, better fluidity, lower hygroscopicity and better room temperature stability. It has a wider application prospect in the fields of health care products, cosmetics, food additives, etc.

[0037] Comparison of Differential Scanning Calorimetry and Thermogravimetric Analysis Different amorphous states of amorphous compounds have unique physical, thermodynamic and kinetic characteristics. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) can detect the unique thermodynamic properties or weight loss percentage of amorphous compounds.

[0038] By comparing the DSC analysis of Example 5 and Example 2, the amorphous product of Example 5 has a higher melting point temperature and a higher glass transition temperature. A higher melting point and a higher glass transition temperature represent that the product has higher thermal stability.

[0039] By comparing the product analysis of Example 5 and Example 2, the TG curve shows that the product of Example 5 has a more obvious curve platform area, and the DTG curve shows that the product of Example 5 has a higher maximum weight loss rate temperature. Generally, the higher the maximum weight loss rate temperature, the higher the thermal decomposition temperature of the sample, and the better the thermal stability.

[0040] Raman spectrum comparative analysis: Since amorphous compounds show diffuse peaks in PXRD and do not have sharp diffraction peaks, it is difficult to identify amorphous compounds using traditional powder X-ray diffraction technology (PXRD). Raman spectroscopy technology uses the vibration-rotation transition energy level differences or molecular polarizability changes of certain chemical bonds in amorphous compound molecules to identify them through differences in frequency, peak shape, peak position, peak intensity, etc. of characteristic spectra, which helps to more accurately identify the amorphous state of amorphous compounds. By comparing Raman spectra (see Appendix Fig. 9 and 10 ) It can be seen that the Raman spectra of the amorphous compound obtained by crystallization in Example 5 of the present invention and the amorphous compound obtained by freeze-drying in Example 2 have obvious differences in displacement and intensity, indicating that the two amorphous compounds have different amorphous forms, and this difference directly affects the stability, hygroscopicity and other properties of the amorphous compound.

[0041] Raman spectrum test was performed by scanning with a laser confocal Raman spectrometer, with an excitation wavelength of 532 nm, a grating of 600 lines, a 50x objective lens, an integration time of 5 s, and 3 accumulation times.

[0042] By comparing the Raman spectra of the products of Example 5 and Example 2, it can be seen that the characteristic peak shifts and intensities of the two are different, indicating that the two exist in different amorphous forms.

[0043] Stability test 1: The reduced β-nicotinamide mononucleotide disodium salt amorphous compound prepared in Example 5 of the present invention and the amorphous lyophilized powder obtained in Example 2 were respectively placed in sealed ziplock bags, and the stability was investigated at room temperature of 25° C.-35° C. and 65%-85% RH. The stability investigation results were shown in the following table.

[0044]

[0045] As can be seen from the above table, the room temperature stability of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound prepared in Example 5 of the present invention is significantly better than the reduced nicotinamide mononucleotide disodium salt amorphous lyophilized powder prepared in Example 2 of the present invention, and the purity decreases by less than 1% within 3 months under the condition of being placed in a sealed ziplock bag at room temperature (25°C-35°C, 65%-85%RH), and the stability is significantly increased. At the same time, it can be seen from the above table that the residual moisture of the obtained reduced nicotinamide mononucleotide disodium salt solid powder has a significant effect on the room temperature stability of the product. After the residual moisture exceeds 10%, the degradation is significantly accelerated. The room temperature stability of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound prepared in Example 5 of the present invention is significantly better than the reduced nicotinamide mononucleotide disodium salt amorphous lyophilized powder obtained in Example 2. From the perspective of the rate of water increase during storage at room temperature, the rate of water increase of the reduced nicotinamide mononucleotide disodium salt amorphous freeze-dried powder obtained in Example 2 is significantly higher than that of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound obtained in Example 5, and the reduced β-nicotinamide mononucleotide disodium salt amorphous compound obtained in Example 5 has a lower initial residual water.

[0046] Stability investigation 2: The reduced β-nicotinamide mononucleotide disodium salt amorphous compound prepared in Example 5 and the amorphous lyophilized powder obtained in Example 2 were placed in a constant temperature and humidity chamber at 25° C. and 65% RH, respectively, and the stability was investigated under room temperature. The stability investigation results were shown in the following table.

[0047]

[0048] As can be seen from the above table, the open room temperature stability of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound of Example 5 is significantly better than the reduced nicotinamide mononucleotide disodium salt amorphous freeze-dried powder of Example 2. At the same time, it can be seen from the above table that residual moisture has a significant effect on the room temperature stability of the product. The room temperature stability of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound obtained in Comparative Example 5 is significantly better than the reduced nicotinamide mononucleotide disodium salt amorphous freeze-dried powder obtained in Example 2. From the perspective of the rate of increase in moisture during open room temperature placement, the rate of increase in moisture of the reduced nicotinamide mononucleotide disodium salt amorphous freeze-dried powder prepared in Example 2 is significantly higher than that of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound prepared in Example 5. At the same time, the obtained reduced nicotinamide mononucleotide disodium salt solid powder soon darkened in color to varying degrees and degraded rapidly when exposed to air. It is speculated that this may be due to the high reduction activity of the 1,4-dihydropyridine ring in the structure of reduced β-nicotinamide mononucleotide disodium salt, which is easily degraded by redox reaction with oxygen in the air under high humidity conditions. Therefore, the humidity of reduced β-nicotinamide mononucleotide disodium salt should be controlled under long-term storage conditions, and the air should be isolated as much as possible.

[0049] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for preparing reduced β-nicotinamide mononucleotide disodium salt, characterized in that: The following steps are included: (1) Using β-nicotinamide mononucleotide as a raw material, thiourea dioxide as a reducing agent, and pure water as a reaction solvent, the reduced β-nicotinamide mononucleotide aqueous solution is obtained by reaction under alkaline conditions; (2) separating and purifying the reduced β-nicotinamide mononucleotide aqueous solution using a high performance preparative liquid chromatography; (3) removing the ammonium salt with a strong acidic cation exchange resin, concentrating the solution through nanofiltration with a nanofiltration membrane, and adjusting the pH value with a sodium hydroxide solution to obtain a concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt; (4) adding a poor solvent to the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt; (5) stirring and adding seed crystals; (6) Continuously stirring and producing suspended sediment; (7) Continue to add poor solvent to increase the yield; (8) Filter and dry to obtain the reduced β-nicotinamide mononucleotide disodium salt amorphous compound.

2. The preparation method according to claim 1, characterized in that: In step (1), a β-nicotinamide mononucleotide aqueous solution is first prepared, and a base is added to adjust the pH value to 9.5-10.0, and then thiourea dioxide is added to the solution to start the reaction. The pH value is maintained at 9.5-10.0 during the reaction process.

3. The preparation method according to claim 1, characterized in that: In step (4), the temperature of the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt is 0°C-25°C, and the poor solvent is 95% ethanol.

4. The preparation method according to claim 1, characterized in that: The seed crystal is ribose or glucose or reduced β-nicotinamide mononucleotide disodium salt prepared by using ribose or glucose as a precipitating primer.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The mass percentage concentration of reduced β-nicotinamide mononucleotide disodium salt in the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt in step (4) is 5%-15%.

6. The preparation method according to claim 5, characterized in that: The reaction temperature of step (1) is 39°C-44°C; the drying temperature of step (8) is 20°C-35°C.

7. The preparation method according to claim 4, characterized in that: The poor solvent is 95% ethanol. The mass of the poor solvent added in step (4) is 1.5-4.0 times the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt. The mass of the poor solvent added dropwise in step (7) is 3.5-6.0 times the concentrated aqueous solution of reduced β-nicotinamide mononucleotide disodium salt.

8. The reduced β-nicotinamide mononucleotide disodium salt obtained by the preparation method according to any one of claims 1 to 7.

9. The reduced β-nicotinamide mononucleotide disodium salt according to claim 8, characterized in that The reduced β-nicotinamide mononucleotide disodium salt is an amorphous compound. When detected by differential scanning calorimeter, it has two characteristic glass transition temperatures at 63.69°C-74.67°C and 85.52°C-131.99°C, and the peak values ​​of the two characteristic glass transition temperatures are 68.78°C and 112.93°C, respectively; it has a characteristic melting point temperature at 217.21°C-241.88°C, and the peak value of the characteristic melting point temperature is 231.70°C; when scanned by laser confocal Raman spectrometer, the Raman shift is 814cm -1 and 845cm -1 There are characteristic peaks.

10. Use of the reduced β-nicotinamide mononucleotide disodium salt amorphous compound as claimed in claim 8 as a raw material for preparing health products, cosmetics and food additives.

Images