Preparation method of high-purity D-calcium pantothenate

Abstract

This invention belongs to the field of pharmaceutical compound preparation technology and relates to a method for preparing high-purity D-calcium pantothenate. The technical solution adopted in this invention is as follows: A combination of anion exchange resin (converted to hydroxyl form), cation exchange resin (converted to hydrogen form), and weakly polar macroporous adsorption resin is used to treat the bio-fermentation broth of D-calcium pantothenate to obtain a purified D-pantothenic acid solution; this D-pantothenic acid solution is then passed through a cation exchange resin (converted to calcium ion form) to convert it into a D-calcium pantothenate solution, followed by activated carbon decolorization and evaporation concentration to obtain high-purity D-calcium pantothenate. The preparation method of this invention is simple to operate, has a high yield, produces high-quality products, and is suitable for industrialization. The prepared D-calcium pantothenate is suitable for further preparation of pharmaceuticals and health products.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical compound preparation technology, and more specifically, relates to a method for preparing a high-purity chiral compound, D-calcium pantothenate. Background Technology

[0002] D-Calcium pantothenate, a B vitamin, is one of the essential nutrients for normal growth of organisms and is widely used in the medical and health care fields. D-Calcium pantothenate also serves as a component of coenzyme A, participating in the metabolism of carbohydrates, fats, and proteins, and is an indispensable trace element for maintaining normal physiological functions in humans and animals.

[0003] Calcium pantothenate, chemically known as N-(2,4-dihydroxy-3,3-dimethylbutyryl)-β-aminopropionate calcium, also called calcium pantothenate, appears as white or slightly yellow needle-like crystals or powder. Its chemical formula is as follows:

[0004]

[0005] Calcium pantothenate exists in three forms due to the presence of chiral carbon atoms: DL-form (jamutative), D-form (dextral), and L-form (levorotatory), with only D-calcium pantothenate possessing biological activity.

[0006] Many documents report on the chemical synthesis of D-calcium pantothenate, such as the articles "Synthesis Technology and Application of D-Calcium Pantothenate" (Li Lichang, *Hubei Chemical Industry*, 2002, No. 2, pp. 30-31) and "Synthesis Technology and Progress of D-Calcium Pantothenate" (Yang Yihong et al., *Feed Industry*, 2004, Vol. 25, No. 6, pp. 8-11). Patent document CN1319937C relates to a method for synthesizing D-calcium pantothenate. As an example, the synthesis of D-calcium pantothenate is relatively complex, including the following steps: mixing γ-butyrolactone, resolving it, and then amidating it with calcium β-alanine to obtain D-calcium pantothenate; or, mixing γ-butyrolactone without resolving it and amidating it with calcium β-alanine to obtain mixing γ-butyrolactone, which is then resolved to obtain D-calcium pantothenate. It is evident that the chemical synthesis of D-calcium pantothenate uses many chemical reagents, involves many steps, and also involves resolving, which is disadvantageous in terms of toxicity and pollution.

[0007] With the continuous development of biotechnology, the production of D-calcium pantothenate using microbial bio-fermentation has advantages such as low cost, mild reaction conditions, and minimal environmental pollution. Chinese patent document CN1946851B discloses a method for preparing D-calcium pantothenate, which includes separating and purifying D-calcium pantothenate from the fermentation culture broth of microorganisms producing pantothenic acid. The method is characterized by the following steps: (a) eluting D-pantothenic acid from a strongly basic anion exchange resin with a 10-20% w / w aqueous acetic acid solution; (b) neutralizing the eluent by adding a basic calcium salt; and (c) converting the solution into a free-flowing product that can be used as an animal feed supplement.

[0008] Initially, D-calcium pantothenate was mainly used as a feed additive. However, with its increasing application in human health products and pharmaceuticals, there is a need for high-purity, high-quality D-calcium pantothenate. D-calcium pantothenate is produced using microbial bio-fermentation. The fermentation broth contains insoluble substances such as microbial cells, as well as sugars, proteins, inorganic salts, and various unknown impurities. CN1946851B provides feed-grade D-calcium pantothenate raw materials.

[0009] Therefore, it is necessary to conduct continuous research and improvement on the preparation of D-calcium pantothenate in order to meet the demand for D-calcium pantothenate of different qualities and to satisfy the various quality requirements of the market. Summary of the Invention

[0010] Technical issues

[0011] Therefore, this invention was made to solve the above-mentioned problems in the prior art. The purpose of this invention is to provide a method for preparing high-purity D-calcium pantothenate, which is simple to operate, has a high yield, produces high-quality products, and is suitable for industrialization. The prepared D-calcium pantothenate is suitable for further preparation of pharmaceuticals and health products.

[0012] Technical solution

[0013] To achieve the above-mentioned objectives of this invention, the technical solution adopted by this invention is as follows: The bio-fermentation broth of D-calcium pantothenate is treated with a combination of anion exchange resin (converted to hydroxyl form), cation exchange resin (converted to hydrogen form), and weakly polar macroporous adsorption resin to obtain a purified D-pantothenic acid solution; this D-pantothenic acid solution is then converted to a D-calcium pantothenate solution by passing it through a cation exchange resin (converted to calcium ion form), followed by decolorization with activated carbon and evaporation concentration to obtain high-purity D-calcium pantothenate.

[0014] According to the present invention, a method for preparing high-purity D-calcium pantothenate is provided, the method comprising the following steps:

[0015] (1) Purification treatment

[0016] The filtered bio-fermentation broth of D-calcium pantothenate was passed through a hydroxide-type anion exchange resin to obtain a decolorized and desalted fermentation broth. This decolorized and desalted fermentation broth was then passed through a hydrogen-type cation exchange resin for cation exchange, converting it into a D-pantothenic acid solution. The D-pantothenic acid solution was then passed through a weakly polar macroporous adsorption resin, where D-pantothenic acid was adsorbed. The adsorbed D-pantothenic acid was then desorbed using a desorption agent to obtain a D-pantothenic acid desorption solution.

[0017] The hydroxyl-type anion exchange resin is an anion exchange resin that has been transformed into a hydroxyl-type anion exchange resin through alkali activation treatment, and the hydrogen-type cation exchange resin is a cation exchange resin that has been transformed into a hydrogen-type cation exchange resin through acid activation treatment.

[0018] (2) Preparation of D-calcium pantothenate

[0019] The D-pantothenic acid eluent obtained above is passed through a calcium ion-type cation exchange resin to convert it into a D-calcium pantothenic acid solution. The D-calcium pantothenic acid solution is then decolorized with activated carbon and concentrated by evaporation to obtain solid D-calcium pantothenic acid. The calcium ion-type cation exchange resin is a cation exchange resin that has been converted into a calcium ion-type cation exchange resin through acid activation and treatment with calcium chloride solution.

[0020] Beneficial effects

[0021] The advantages of this invention are as follows: The sequential combination of anion exchange resin (converted to hydroxyl form), cation exchange resin (converted to hydrogen form), and weakly polar macroporous adsorption resin effectively purifies the filtered bio-fermentation broth of D-calcium pantothenate, removing impurities such as salts (including inorganic anions and cations), pigments, and nonpolar substances, thus obtaining a purified D-pantothenic acid solution. This D-pantothenic acid solution is then converted into a purified D-calcium pantothenate solution by passing it through a cation exchange resin (converted to calcium ion form), resulting in high-purity D-calcium pantothenate. Furthermore, this preparation method is simple to operate, has a high yield, produces high-quality products, and is suitable for industrialization. Detailed Implementation

[0022] The preparation method of high-purity D-calcium pantothenate according to the present invention will be described in more detail below to aid in understanding the present invention.

[0023] According to one embodiment of the present invention, in the method for preparing high-purity D-calcium pantothenate, an anion exchange resin (converted to hydroxyl form), a cation exchange resin (converted to hydrogen form), and a weakly polar macroporous adsorption resin are sequentially combined to treat the bio-fermentation broth of D-calcium pantothenate to obtain a purified D-pantothenic acid solution. Specifically, in the purification step, the filtered bio-fermentation broth of D-calcium pantothenate is passed through a hydroxyl anion exchange resin to obtain a decolorized and desalted fermentation broth; the decolorized and desalted fermentation broth is then passed through a hydrogen cation exchange resin for cation exchange, converting it into a D-pantothenic acid solution; the D-pantothenic acid solution is then passed through a weakly polar macroporous adsorption resin, where D-pantothenic acid is adsorbed onto the resin; and then a desorption agent is used to desorb the D-pantothenic acid adsorbed on the resin to obtain a D-pantothenic acid desorption solution; wherein, the hydroxyl anion exchange resin is an anion exchange resin converted to hydroxyl anion exchange resin through alkali activation treatment, and the hydrogen cation exchange resin is a cation exchange resin converted to hydrogen cation exchange resin through acid activation treatment.

[0024] The filtered D-calcium pantothenate bio-fermentation broth refers to the clarified fermentation broth obtained by filtering the original D-calcium pantothenate bio-fermentation broth produced through microbial fermentation. The original D-calcium pantothenate bio-fermentation broth is a fermentation broth obtained through microbial fermentation. This broth typically has a pH of 6.5–7.5, and the concentration of D-calcium pantothenate, measured from the centrifuged supernatant, is 60–85 g / L. The liquid phase purity of D-calcium pantothenate is 50%–60%, and the conductivity is 15–30 mS / cm. It also contains sugars, proteins, inorganic salts, and various unknown impurities. Therefore, the liquid phase purity of D-calcium pantothenate refers to the percentage peak area of ​​D-calcium pantothenate in the chromatogram obtained by HPLC analysis.

[0025] Specifically, in the filtration process, a ceramic membrane is used to pre-treat the original bio-fermentation broth of D-calcium pantothenate to remove mycelia and solids from the fermentation broth, resulting in D-calcium pantothenate ceramic filtrate; then, an ultrafiltration membrane is used to ultra-filter the D-calcium pantothenate ceramic filtrate to remove pigments and soluble proteins, resulting in D-calcium pantothenate ultrafiltrate.

[0026] More specifically, firstly, under conditions of 20℃~40℃, the original bio-fermentation broth of D-calcium pantothenate is pretreated by filtration using a ceramic membrane with a filtration precision of 50nm to remove mycelia and solids from the fermentation broth. When the concentration of the fermentation broth reaches 3~5 times, purified water with a volume of 3~4 times the volume of the concentrate is continuously added for washing and filtration, controlling the balance between the influent and filtrate output. The resulting filtrate is the D-calcium pantothenate ceramic filtrate. The concentration of D-calcium pantothenate in the obtained D-calcium pantothenate ceramic filtrate is generally 35~60g / L.

[0027] Next, the D-calcium pantothenate filtrate was subjected to ultrafiltration at 20℃–40℃ using an ultrafiltration membrane with a molecular weight cutoff of 1000–5000 Daltons, more preferably 2000–3000 Daltons, to remove pigments and soluble proteins, yielding a D-calcium pantothenate ultrafiltrate. If necessary, the concentrate can be washed with purified water during the ultrafiltration process to improve the yield. The concentration of D-calcium pantothenate in the obtained D-calcium pantothenate ultrafiltrate is generally 30–55 g / L.

[0028] In this invention, the filtered D-calcium pantothenate bio-fermentation broth is first treated with a hydroxide-oxygen anion exchange resin, that is, the D-calcium pantothenate ultrafiltrate obtained above is first treated with a hydroxide-oxygen anion exchange resin. Specifically, the D-calcium pantothenate ultrafiltrate obtained above is passed through a hydroxide-oxygen anion exchange resin at a certain flow rate for decolorization and desalination. The column outlet effluent with a transmittance greater than 90% (420 nm) is collected, which is the decolorized and desalted fermentation broth.

[0029] The hydroxyl-type anion exchange resin is obtained by converting anion exchange resin into a hydroxyl-type anion exchange resin through alkali activation treatment. The anion exchange resin used is a weakly basic anion exchange resin, which can be commercially available. For example, one can choose the FPA-53 anion exchange resin produced by Rohm and Haas, or either the LXT-267 or LXT-281 anion exchange resin produced by Xi'an Lanxiao Technology New Materials Co., Ltd. Specifically, the hydroxyl-type anion exchange resin is obtained by converting the anion exchange resin through the following method: the anion exchange resin is activated with sodium hydroxide solution, and then washed with purified water until the eluent is neutral and the conductivity is below 50 μS / cm. The hydroxyl-type anion exchange resin is applied in the form of a circular resin column bed using a wet packing process. The D-calcium pantothenate ultrafiltrate obtained above is passed through the hydroxyl-type anion exchange resin column bed at a certain flow rate, for example, at a flow rate of 1 to 3 times the total resin volume per hour. The collected decolorized and desalted fermentation broth generally contains 25–50 g / L of D-calcium pantothenate, and the liquid phase purity of D-calcium pantothenate is 80%–85%.

[0030] Alternatively, in this step, anion exchange resin can be packed into a resin column bed, then activated with alkali to transform it into a hydroxide-type anion exchange resin, and the D-calcium pantothenate ultrafiltrate obtained above can be passed through the resin column bed to obtain a decolorized and desalted fermentation broth.

[0031] Then, the decolorized and desalted fermentation broth is passed through a hydrogen-form cation exchange resin for cation exchange, converting it into a D-pantothenic acid solution. Specifically, the decolorized and desalted fermentation broth is passed through a hydrogen-form cation exchange resin at a certain flow rate for cation exchange, thereby achieving further decolorization, desalination, and acidification. The column effluent with a pH less than 2.0 is collected, which is the converted D-pantothenic acid solution.

[0032] The hydrogen-form cation exchange resin is obtained by acid activation treatment of cation exchange resin. The cation exchange resin used is a strongly acidic cation exchange resin, commercially available, such as either LXT-101 or LXT-105 produced by Xi'an Lanxiao Technology New Materials Co., Ltd. Specifically, the hydrogen-form cation exchange resin is obtained by treating the cation exchange resin with hydrochloric acid solution for activation, followed by rinsing with purified water until the eluent is neutral and has a conductivity below 50 μS / cm. The hydrogen-form cation exchange resin is applied using a wet-packed circular resin column bed. The decolorized and desalted fermentation broth obtained above is passed through the hydrogen-form cation exchange resin column bed at a certain flow rate, for example, 1 to 3 times the total resin volume per hour. The collected D-pantothenic acid solution typically has a D-pantothenic acid concentration (calculated as D-pantothenic acid calcium) of 23–46 g / L and a pantothenic acid liquid phase purity of 86%–92%. Alternatively, in this step, a cation exchange resin can be filled into a resin column bed, then converted to a hydrogen-form cation exchange resin by acid activation treatment, and the decolorized and desalted fermentation broth obtained above can be passed through the resin column bed to obtain a D-pantothenic acid solution.

[0033] Next, the D-pantothenic acid solution is passed through a weakly polar macroporous adsorption resin, where D-pantothenic acid is adsorbed. The weakly polar macroporous adsorption resin can have a pore size of 10–30 nanometers, a particle size of 300–500 micrometers, and a specific surface area of ​​450–800 m². 2 / g of a styrene-based, weakly polar macroporous adsorption resin with a styrene framework. For example, any one of the following weakly polar macroporous adsorption resins produced by Ningbo Zhengguang Resin Co., Ltd. can be selected: DM130, SD-8, and CAD45. The weakly polar macroporous adsorption resin is applied in the form of a circular resin column bed using a wet packing process. The height-to-diameter ratio (height-to-diameter ratio) of the circular resin column bed should be greater than or equal to 4. The obtained D-pantothenic acid solution is passed through the weakly polar macroporous adsorption resin at a certain flow rate, for example, 0.5 to 2 times the total resin volume per hour, preferably 0.5 to 1 times the total resin volume per hour. In actual operation, the flow is stopped upon detection of D-pantothenic acid at the bottom outlet of the column bed.

[0034] D-Pantothenic acid is adsorbed onto a weakly polar macroporous adsorption resin. The adsorbed D-pantothenic acid is then desorbed using a desorbent to obtain a D-pantothenic acid eluent. The desorbent used is a mixture of methanol and water at a volume ratio of 60–100:40–0, preferably 80–100:20–0. The flow rate of the desorbent is 0.5–1 times the total resin volume per hour. Eluent is collected from the start of the desorption process. Collection is stopped when the D-pantothenic acid concentration in the effluent is below 0.5 g / L (calculated as calcium D-pantothenate). This collected portion is the D-pantothenic acid eluent. The typical D-pantothenic acid concentration (calculated as calcium D-pantothenate) is 73–95 g / L, and the liquid phase purity of D-pantothenic acid is greater than or equal to 98%.

[0035] According to one embodiment of the present invention, in step (2) preparation of D-calcium pantothenate, the D-pantothenic acid eluent obtained above is passed through a calcium ion-type cation exchange resin to convert it into a D-calcium pantothenate solution. The D-calcium pantothenate solution is decolorized by activated carbon and concentrated by evaporation to obtain solid D-calcium pantothenate. The calcium ion-type cation exchange resin is a cation exchange resin that has been transformed into a calcium ion-type cation exchange resin by acid activation and treatment with calcium chloride solution.

[0036] The calcium ion-type cation exchange resin is obtained by converting a cation exchange resin into a calcium ion-type cation exchange resin through acid activation and treatment with calcium chloride solution. The cation exchange resin used is a strongly acidic cation exchange resin, which can be commercially available. For example, either LXT-101 or LXT-105 cation exchange resins produced by Xi'an Lanxiao Technology New Materials Co., Ltd., used in step (1), can be selected. Specifically, the calcium ion-type cation exchange resin is converted by treating the cation exchange resin as follows: the cation exchange resin is activated with hydrochloric acid solution to convert it into the hydrogen form, and then rinsed with purified water until the eluent is neutral; then, the resin is treated with calcium chloride solution to convert it into the calcium ion form, and then rinsed with purified water until the eluent does not contain calcium chloride and the conductivity is less than 50 μS / cm. The calcium ion-type cation exchange resin is applied using a wet-packed column in the form of a circular resin bed. The D-pantothenic acid eluent obtained above is passed through the calcium ion-type cation exchange resin column bed at a certain flow rate, for example, 0.5 to 1 times the total resin volume per hour. The column effluent with a pH greater than 6.0 is collected, which is the converted D-calcium pantothenate solution. The collected D-calcium pantothenate solution generally has a D-calcium pantothenate concentration of 70 to 90 g / L, and a liquid phase purity of D-calcium pantothenate greater than or equal to 99%.

[0037] Alternatively, in this step, a cation exchange resin can be filled into a resin column bed, then acid-activated and treated with calcium chloride solution to transform it into a calcium ion-type cation exchange resin. The D-pantothenic acid eluent obtained above can then be passed through the resin column bed to obtain a D-calcium pantothenic acid solution.

[0038] Next, activated carbon is added to the D-calcium pantothenate solution, at a rate of 0.2–0.5 grams per 100 ml of solution. After stirring and decolorizing for 30–60 minutes, the solution is filtered to obtain a decolorized D-calcium pantothenate solution. Then, under vacuum concentration at 60–80°C, methanol and water are removed from the D-calcium pantothenate solution to obtain a D-calcium pantothenate product that meets quality standards. For example, methanol can be recovered first by distillation, and then the D-calcium pantothenate product can be obtained directly by spray drying.

[0039] The following examples illustrate the preparation method of high-purity D-calcium pantothenate according to the present invention in more detail, but the scope of protection of the present invention is not limited to these examples.

[0040] Filtration treatment of D-calcium pantothenate bio-fermentation broth

[0041] 150 L of D-calcium pantothenate bio-fermentation broth was taken, with a pH of 7.2. The concentration of D-calcium pantothenate was measured to be 75 g / L in the centrifuged supernatant, with a liquid phase purity of 53% and a conductivity of 25 mS / cm. The fermentation broth was pretreated by filtration using a ceramic membrane with a filtration precision of 50 nm at 23 °C. After the volume was concentrated to 30 L, the concentrate was continuously washed with 90 L of purified water, yielding 210 L of ceramic filtrate with a D-calcium pantothenate concentration of 46 g / L. The ceramic filtrate was then treated with an ultrafiltration membrane with a molecular weight cutoff of 2500 Daltons, and the concentrate was washed appropriately with purified water, yielding 240 L of ultrafiltrate with a D-calcium pantothenate concentration of 39 g / L.

[0042] Resin treatment

[0043] Hydroxy-type anion exchange resin is obtained by treating anion exchange resin as follows: the anion exchange resin is activated with 4-5% (w / v) sodium hydroxide solution, and then washed with purified water until the eluent is neutral and the conductivity is less than 50 μs / cm.

[0044] Hydrogen-form cation exchange resin is obtained by treating cation exchange resin as follows: the cation exchange resin is activated with 4-5% (w / v) hydrochloric acid solution, and then rinsed with purified water until the washing solution is neutral and the conductivity is less than 50 μs / cm.

[0045] Pretreatment of weakly polar macroporous adsorption resin: activate with methanol, then rinse the resin with purified water until there is no methanol odor;

[0046] The calcium ion cation exchange resin was converted to the cation exchange resin by the following method: the cation exchange resin was activated with 4-5% (w / v) hydrochloric acid solution to convert it to the hydrogen form, and then rinsed with purified water until the eluent was neutral; then, the resin was treated with 0.5 mol / L calcium chloride solution to convert it to the calcium ion form, and then rinsed with purified water until the eluent was free of calcium chloride and the conductivity was less than 50 μS / cm.

[0047] Example 1

[0048] The obtained D-calcium pantothenate ultrafiltrate (97 L) was passed through a hydrogen-oxygen anion exchange resin (LXT-281, wet-packed column, 10 L, aspect ratio 4) at a flow rate of 10 L / h. The column effluent with a transmittance greater than 90% (420 nm) was collected; this was the decolorized and desalted fermentation broth. Then, the decolorized and desalted fermentation broth was passed through a hydrogen-type cation exchange resin (Cation exchange resin type...) at a flow rate of 10 L / h. The column was packed using LXT-101 wet packing (10L capacity, height-to-diameter ratio 4). The effluent with a pH less than 2.0 was collected as the converted D-pantothenic acid solution. This D-pantothenic acid solution was then passed through a weakly polar macroporous adsorption resin (DM130, wet packing, 20L capacity, height-to-diameter ratio 4) at a flow rate of 10L per hour. D-pantothenic acid was adsorbed onto the weakly polar macroporous adsorption resin. The column was stopped when D-pantothenic acid was detected at the bottom of the column bed.

[0049] Then, methanol was used as the eluent to desorb D-pantothenic acid adsorbed on the weakly polar macroporous adsorption resin. Methanol was passed through the resin column bed at a flow rate of 20 L / h. Collection was stopped when the concentration of D-pantothenic acid in the effluent at the bottom of the column was lower than 0.5 g / L, and 40 L of D-pantothenic acid eluent was collected, with a pantothenic acid concentration of 88 g / L (calculated as calcium D-pantothenate) and a liquid phase purity of 98.4%. Next, the D-pantothenic acid eluent was passed through a calcium ion-type cation exchange resin (Cation exchange resin model LXT-101, wet packing, 10 L, height-to-diameter ratio 4) at a flow rate of 10 L / h. The effluent with a pH greater than 6.0 was collected, which was the calcium D-pantothenate solution. Then, 200 g of activated carbon was added, and the mixture was stirred and decolorized for 30 minutes. After filtration, the decolorized calcium D-pantothenate solution was obtained. Then, the methanol and water were removed by vacuum concentration at 70-80℃ to obtain 3485 g of calcium D-pantothenate product. The yield from ultrafiltrate to product was 92.1%. The D-calcium pantothenate product was a white powder with a content of 99.6% and a specific rotation [α]20 / D = 27.5 (C = 5% in H2O).

[0050] Example 2

[0051] The obtained D-calcium pantothenate ultrafiltrate (95 L) was passed through a hydrogen-oxygen anion exchange resin (LXT-281, wet-packed column, 10 L, aspect ratio 4) at a flow rate of 10 L / h. The column effluent with a transmittance greater than 90% (420 nm) was collected; this was the decolorized and desalted fermentation broth. Then, the decolorized and desalted fermentation broth was passed through a hydrogen-type cation exchange resin (Cation exchange resin type...) at a flow rate of 10 L / h. The column was packed using LXT-101 wet packing (10L capacity, height-to-diameter ratio 4). The effluent with a pH less than 2.0 was collected as the converted D-pantothenic acid solution. This D-pantothenic acid solution was then passed through a weakly polar macroporous adsorption resin (CAD45, wet packing, 20L capacity, height-to-diameter ratio 4) at a flow rate of 10L per hour. D-pantothenic acid was adsorbed onto the weakly polar macroporous adsorption resin. The column was stopped when D-pantothenic acid was detected at the bottom of the column bed.

[0052] Then, methanol / water (90:10 by volume) was used as the eluent to desorb D-pantothenic acid adsorbed on the weakly polar macroporous adsorption resin. The methanol / water flow rate was 10 L / h through the resin column bed. Collection was stopped when the concentration of D-pantothenic acid in the effluent at the bottom of the column was less than 0.5 g / L. 40 L of D-pantothenic acid eluent was collected, with a pantothenic acid concentration of 85 g / L (calculated as calcium D-pantothenate) and a liquid phase purity of 98.2%. Next, the D-pantothenic acid eluent was passed through a calcium ion-type cation exchange resin (Cation exchange resin model: LXT-101, wet-packed column, 10L capacity, height-to-diameter ratio: 4) at a flow rate of 10L per hour. The column effluent with a pH greater than 6.0 was collected, which was the D-calcium pantothenate solution. Then, 200g of activated carbon was added, and the mixture was stirred and decolorized for 30 minutes before filtration to obtain the decolorized D-calcium pantothenate solution. Then, the solution was concentrated under vacuum at 70-80℃ to remove methanol and water, yielding 3298g of D-calcium pantothenate product. The yield from ultrafiltrate to product was 89.0%. The D-calcium pantothenate product was a white powder with a purity of 99.5% and a specific rotation [α]20 / D = 27.4 (C = 5% in H2O).

[0053] Example 3

[0054] 100 L of the D-calcium pantothenate ultrafiltrate obtained above was passed through a hydrogen-oxygen anion exchange resin (anion exchange resin type LXT-281, wet-packed column, 10 L capacity, aspect ratio 4) at a flow rate of 10 L per hour. The column effluent with a transmittance greater than 90% (420 nm) was collected, which is the decolorized and desalted fermentation broth. Then, the decolorized and desalted fermentation broth was passed through a hydrogen-type cation exchange resin (cation exchange resin type) at a flow rate of 10 L per hour. The column (model LXT-105, wet packing, 10L capacity, height-to-diameter ratio 4) is used to collect the column effluent with a pH less than 2.0, which is the converted D-pantothenic acid solution. This D-pantothenic acid solution is then passed through a weakly polar macroporous adsorption resin (model CAD45, wet packing, 20L capacity, height-to-diameter ratio 4) at a flow rate of 10L per hour. D-pantothenic acid is adsorbed onto the weakly polar macroporous adsorption resin. The column is stopped when D-pantothenic acid is detected at the bottom outlet of the column bed.

[0055] Then, methanol was used as the eluent to desorb D-pantothenic acid adsorbed on the weakly polar macroporous adsorption resin. Methanol was passed through the resin column bed at a flow rate of 10 L / h. Collection was stopped when the concentration of D-pantothenic acid in the effluent at the bottom of the column was lower than 0.5 g / L, and 40 L of D-pantothenic acid eluent was collected, with a pantothenic acid concentration of 93 g / L (calculated as calcium D-pantothenate) and a liquid phase purity of 98.6%. Next, the D-pantothenic acid eluent was passed through a calcium ion-type cation exchange resin (Cation exchange resin model LXT-105, wet packing, 10 L, height-to-diameter ratio 4) at a flow rate of 10 L / h. The effluent with a pH greater than 6.0 was collected, which was the calcium D-pantothenate solution. Then, 200 g of activated carbon was added, and the mixture was stirred and decolorized for 30 minutes. After filtration, the decolorized calcium D-pantothenate solution was obtained. Then, the methanol and water were removed by vacuum concentration at 70-80℃ to obtain 3646 g of calcium D-pantothenate product. The yield from ultrafiltrate to product was 93.5%. The D-calcium pantothenate product was a white powder with a content of 99.5% and a specific rotation [α]20 / D = 27.6 (C = 5% in H2O).

Claims

1. A method for preparing high-purity D-calcium pantothenate, the method comprising the following steps: (1) Purification treatment The filtered bio-fermentation broth of D-calcium pantothenate was passed through a hydroxide-type anion exchange resin to obtain a decolorized and desalted fermentation broth. This decolorized and desalted fermentation broth was then passed through a hydrogen-type cation exchange resin for cation exchange, converting it into a D-pantothenic acid solution. The D-pantothenic acid solution was then passed through a weakly polar macroporous adsorption resin, where D-pantothenic acid was adsorbed. The adsorbed D-pantothenic acid was then desorbed using a desorption agent to obtain a D-pantothenic acid desorption solution. in, The hydroxide-oxygen anion exchange resin is an anion exchange resin that has been converted to hydroxide-oxygen anion exchange resin through alkali activation treatment, and the anion exchange resin used is a weakly basic anion exchange resin; the hydrogen-form cation exchange resin is a cation exchange resin that has been converted to hydrogen-form cation exchange resin through acid activation treatment, and the cation exchange resin used is a strongly acidic cation exchange resin; the weakly polar macroporous adsorption resin has a pore size of 10-30 nanometers, a particle size of 300-500 micrometers, and a specific surface area of ​​450-800 m². 2 / g of styrene-based styrene-based weakly polar macroporous adsorption resin; (2) Preparation of D-calcium pantothenate The D-pantothenic acid eluent obtained above was passed through a calcium ion-type cation exchange resin to convert it into a D-calcium pantothenic acid solution. This D-calcium pantothenic acid solution was then decolorized with activated carbon and concentrated by evaporation to obtain solid D-calcium pantothenic acid. The calcium ion-type cation exchange resin was converted from a cation exchange resin by acid activation and treatment with calcium chloride solution; the cation exchange resin used was a strongly acidic cation exchange resin. The filtered D-calcium pantothenate bio-fermentation broth refers to the clarified fermentation broth obtained by filtering the original D-calcium pantothenate bio-fermentation broth obtained by microbial fermentation. In the filtration process, a ceramic membrane is used to pre-treat the original D-calcium pantothenate bio-fermentation broth to remove mycelia and solids, resulting in D-calcium pantothenate ceramic filtrate. Then, an ultrafiltration membrane is used to ultra-filter the D-calcium pantothenate ceramic filtrate to remove pigments and soluble proteins, resulting in D-calcium pantothenate ultrafiltrate. The original D-calcium pantothenate bio-fermentation broth has a pH of 6.5–7.5, a D-calcium pantothenate concentration of 60–85 g / L as measured by centrifugation supernatant, a liquid phase purity of 50%–60%, and a conductivity of 15–30 mS / cm. In the purification step, the D-calcium pantothenate ultrafiltrate obtained above is passed through a hydroxide-type anion exchange resin column bed, and the column outlet effluent with a transmittance greater than 90% at 420 nm is collected, which is the decolorized and desalted fermentation broth, wherein the concentration of D-calcium pantothenate is 25-50 g / L; the decolorized and desalted fermentation broth is passed through a hydrogen-type cation exchange resin column bed, and the column outlet effluent with a pH less than 2.0 is collected, which is the converted D-pantothenic acid solution, wherein the concentration of D-pantothenic acid is 23-46 g / L, calculated as D-calcium pantothenate; the D-pantothenic acid solution is passed through a weakly polar macroporous adsorption resin column bed, where D-pantothenic acid is adsorbed onto the weakly polar macroporous adsorption resin, and then the D-pantothenic acid adsorbed on the resin is desorbed using an eluent prepared by methanol and water at a volume ratio of 60-100:40-0, to obtain a D-pantothenic acid eluent, wherein the concentration of D-pantothenic acid is 73-95 g / L, calculated as D-calcium pantothenate; In step (2) preparation of D-calcium pantothenate, the D-pantothenic acid eluent obtained above is passed through a calcium ion-type cation exchange resin column bed, and the column outlet effluent with pH greater than 6.0 is collected, which is the converted D-calcium pantothenate solution, wherein the concentration of D-calcium pantothenate is 70-90 g / L, and the liquid phase purity of D-calcium pantothenate is greater than or equal to 99%.

2. The method for preparing high-purity D-calcium pantothenate according to claim 1, characterized in that, in In the purification process, the hydroxide-type anion exchange resin is converted by treating the anion exchange resin as follows: the anion exchange resin is activated with sodium hydroxide solution, and then rinsed with purified water until the eluent is neutral and the conductivity is less than 50 μs / cm.

3. The method for preparing high-purity D-calcium pantothenate according to claim 1, characterized in that, in In the purification process, the hydrogen-form cation exchange resin is converted to the cation exchange resin by the following method: the cation exchange resin is activated with hydrochloric acid solution, and then rinsed with purified water until the eluent is neutral and the conductivity is less than 50 μs / cm.

4. The method for preparing high-purity D-calcium pantothenate according to claim 1, characterized in that, In step (2) D-calcium pantothenate preparation, the calcium ion type cation exchange resin is converted by treating the cation exchange resin as follows: the cation exchange resin is activated by hydrochloric acid solution to convert it to the hydrogen form, and then rinsed with purified water until the eluent is neutral; then, the resin is treated with calcium chloride solution to convert it to the calcium ion type, and then rinsed with purified water until the eluent does not contain calcium chloride and the conductivity is less than 50 μs / cm.

5. The method for preparing high-purity D-calcium pantothenate according to claim 1, characterized in that, In the filtration process, the concentration of D-calcium pantothenate in the resulting D-calcium pantothenate filtrate is 35–60 g / L.

6. The method for preparing high-purity D-calcium pantothenate according to claim 1, characterized in that, In the filtration process, under conditions of 20℃~40℃, an ultrafiltration membrane with a molecular weight cutoff of 1000~5000 Daltons was used to ultrafilter the D-calcium pantothenate filtrate to obtain D-calcium pantothenate ultrafiltrate. The concentration of D-calcium pantothenate in the obtained D-calcium pantothenate ultrafiltrate is 30~55g / L.

7. The method for preparing high-purity D-calcium pantothenate according to claim 1, characterized in that, in In the purification process, The D-calcium pantothenate ultrafiltrate is passed through a hydrogen-oxygen anion exchange resin column bed at a flow rate of 1 to 3 times the total resin volume per hour. The decolorized and desalted fermentation broth is passed through a hydrogen-type cation exchange resin column bed at a flow rate of 1 to 3 times the total resin volume per hour. The D-pantothenic acid solution is passed through a weakly polar macroporous adsorption resin column at a flow rate of 0.5 to 2 times the total resin volume per hour. D-pantothenic acid is adsorbed onto the weakly polar macroporous adsorption resin. Then, an eluent prepared by mixing methanol and water at a volume ratio of 80 to 100: 20 to 0 is used to elute the D-pantothenic acid adsorbed on the resin to obtain a D-pantothenic acid eluent.

8. The method for preparing high-purity D-calcium pantothenate according to claim 1, characterized in that, In step (2) D-calcium pantothenate preparation, the D-pantothenic acid eluent obtained above is passed through a calcium ion-type cation exchange resin column bed at a flow rate of 0.5 to 1 times the total resin volume per hour.

9. The method for preparing high-purity D-calcium pantothenate according to claim 1, characterized in that, In step (2) of D-calcium pantothenate preparation, the amount of activated carbon used is 0.2 to 0.5 grams of activated carbon added to every 100 ml of D-calcium pantothenate solution. After stirring and decolorizing for 30 to 60 minutes, the solution is filtered to obtain a decolorized D-calcium pantothenate solution. Then, under conditions of 60°C to 80°C, methanol and water in the D-calcium pantothenate solution are removed by vacuum concentration to obtain a D-calcium pantothenate product that meets the quality standards.

Images