A low-odor, high-stability ergothioneine crystal

Abstract

The invention belongs to the field of compound crystal technology, and in particular to a kind of thioneine crystal with low peculiar smell and high stability. The thioneine crystal uses Cu-Kα radiation, and the X-ray diffraction spectrum represented by 2θ has characteristic peaks at least at 9.50 ± 0.2°, 15.52 ± 0.2°, 19.06 ± 0.2°, 24.88 ± 0.2°, 25.48 ± 0.2°, 28.74 ± 0.2°, 29.22 ± 0.2°, 35.10 ± 0.2°. The thioneine new crystal form in the present invention has excellent light stability, and good anti-hygroscopicity, while high decomposition temperature resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of compound crystals, and particularly relates to ergothioneine crystals with low odor and high stability. Background Art

[0002] Ergothioneine (mercaptohistidine trimethyl salt, ergothioneine, EGT), the pure product is white crystals, the molecular formula is C9H 15 N3O2S, molecular weight is 229.09.

[0003] Ergothioneine has a strong antioxidant capacity and can protect cells in the human body. It is an important active substance in the body. It has multiple physiological functions such as scavenging free radicals, detoxification, maintaining DNA biosynthesis, normal cell growth and cell immunity.

[0004] Ergothioneine exists in two isomeric forms: thiol and thione, as follows:

[0005]

[0006] Under light conditions, ergothioneine may degrade and have the smell of trimethylamine. At the same time, the anti-hygroscopicity of ergothioneine needs to be improved.

[0007] Chinese invention patent application CN118221592A discloses a thioneine crystal and a preparation method thereof, wherein the preparation method provided comprises the following steps: stirring thioneine crude product with a purity of 98.0% to 99.9% in 30°C to 40°C warm water until dissolved, cooling down at 5°C to 10°C, and standing to obtain thioneine crystal. However, it does not pay attention to the hygroscopicity resistance and light stability of the product.

[0008] Currently, there is no prior art that discloses novel ergothioneine crystals that can improve the hygroscopicity resistance and light stability.

[0009] Therefore, it is particularly important to develop a crystal form that is more light-resistant, more stable, and less prone to hygroscopicity. Summary of the invention

[0010] In view of the deficiencies in the prior art, the present invention provides an ergothioneine crystal with low odor and high stability.

[0011] In order to achieve the above-mentioned purpose of the present invention, the specific technical solution adopted by the present invention is:

[0012] The invention discloses a low-odor and high-stability ergothioneine crystal. The ergothioneine crystal uses Cu-Kα radiation, and an X-ray diffraction spectrum represented by 2θ has characteristic peaks at least at 9.50±0.2°, 15.52±0.2°, 19.06±0.2°, 24.88±0.2°, 25.48±0.2°, 28.74±0.2°, 29.22±0.2°, and 35.10±0.2°.

[0013] Preferably, the ergothioneine crystal uses Cu-Kα radiation, and the X-ray diffraction spectrum represented by 2θ also has characteristic peaks at 16.10±0.2°, 17.32±0.2°, 20.50±0.2°, 23.98±0.2°, 26.40±0.2°, and 38.62±0.2°.

[0014] Further preferably, the thioneine crystal uses Cu-Kα radiation, and the X-ray diffraction spectrum represented by 2θ also has characteristic peaks at 14.46 ± 0.2°, 21.26 ± 0.2°, 22.28 ± 0.2°, 25.92 ± 0.2°, 29.86 ± 0.2°, 30.26 ± 0.2°, 30.72 ± 0.2°, 32.26 ± 0.2°, 32.76 ± 0.2°, 34.66 ± 0.2°, 35.68 ± 0.2°, 36.56 ± 0.2°, 36.98 ± 0.2°, 37.96 ± 0.2°, 39.24 ± 0.2°.

[0015] Preferably, the characteristic peaks in the X-ray powder diffraction pattern (Cu-Kα) corresponding to the ergothioneine crystal are shown in Figure 7 And Table 1.

[0016] Table 1 Main XRD peaks of ergothioneine crystals

[0017]

[0018]

[0019] Preferably, the maximum weight loss temperature of the ergothioneine crystal is 302-305°C.

[0020] Preferably, the melting point of the ergothioneine crystals is 275-277°C.

[0021] Preferably, the preparation method of the ergothioneine crystal comprises the following steps:

[0022] (1) the crude product of thioneine is mixed with water to prepare a crude product solution of 70-150g / L, ethanol or methanol is added, and crystallization is performed to obtain crystal 1;

[0023] (2) mixing crystal 1 with an aqueous solvent to prepare a solution A having a concentration of 250-500 g / L (crystal 1);

[0024] (3) add ethanol or methanol in solution A until there is crystal precipitation, preserve crystal, continue to add ethanol or methanol, grow the grain, lower the temperature, filter, dry, and obtain described thioneine crystal.

[0025] Further preferably, the amount of ethanol or methanol added in step (1) is 3-7 times the volume of the crude solution, the crystallization temperature is 20-50°C, the crystallization time is 0.5-1.5h, and the crystallization is carried out while stirring at a speed of 300-800rpm.

[0026] Further preferably, the aqueous solvent in step (2) includes water or the crude product solution in step (1), and the total amount of ethanol or methanol added in step (3) is 3-7 times the volume of the crystal 1 solution.

[0027] Further preferably, in step (3), the temperature after adding ethanol or methanol is controlled to be 40-80°C, the crystal preservation time is 0.5-2.5h, and before crystal precipitation, stirring is carried out at a speed of 200-500rpm while adding ethanol or methanol; the crystal growth time is 0.5-3h, the cooling is gradient cooling, cooling by 10°C every 1h to 25-50°C, and the drying temperature is 50-80°C.

[0028] The invention also relates to application of the ergothioneine crystal in preparing food, health products, cosmetics or medicines.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention optimizes the concentration of the solution in the secondary crystallization process, and the finally prepared thioneine new crystal has excellent light stability, good anti-hygroscopicity, and a high decomposition temperature resistance.

[0031] (2) The present invention optimizes the amount of alcohol solvent used in the secondary crystallization process, thereby ensuring good light stability and anti-hygroscopicity while also improving the purity and yield of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a scanning electron microscope image of the new crystal form of thioneine in Example 1;

[0033] Figure 2 It is a scanning electron microscope image of the new crystal form of thioneine in Example 3;

[0034] Figure 3 It is a scanning electron microscope image of the new crystal form of thioneine in Example 4;

[0035] Figure 4 It is a scanning electron microscope image of the new crystal form of thioneine in comparative example 5;

[0036] Figure 5 It is a scanning electron micrograph of a commercially available ergothioneine product;

[0037] Figure 6 It is the powder X-ray diffraction pattern of the new crystal form of thioneine in Example 1;

[0038] Figure 7 It is the powder X-ray diffraction pattern of the new crystal form of thioneine in Example 3;

[0039] Figure 8 It is the powder X-ray diffraction pattern of the new crystal form of thioneine in Example 4;

[0040] Fig. 9 The X-ray diffraction pattern of the new crystal form of thioneine in comparative example 5 is shown in FIG.

[0041] Fig.10 It is the powder X-ray diffraction pattern of commercially available ergothioneine products;

[0042] Fig.11 It is the thermogravimetric analysis diagram of the new crystal form of thioneine in Example 3;

[0043] Fig.12 It is the thermogravimetric analysis diagram of commercially available ergothioneine products. DETAILED DESCRIPTION

[0044] The present invention will be further described in detail below in conjunction with specific examples. The following examples are not intended to limit the present invention, but are only intended to illustrate the present invention. The experimental methods used in the following examples are generally conventional, unless otherwise specified, and the materials, reagents, etc. used in the following examples are commercially available, unless otherwise specified.

[0045] Example 1

[0046] A low-odor, high-stability ergothioneine crystal with Figure 1 The scanning electron micrographs and Figure 6 The powder X-ray diffraction pattern measured using Cu-Kα radiation is shown.

[0047] The preparation method of the ergothioneine crystal is:

[0048] (1) the crude thioneine product was dissolved in water to prepare a crude thioneine solution of 70 g / L, methanol was added (the amount of methanol added was 5 times the volume of the crude thioneine solution), the temperature was controlled at 20 ° C, stirred at 300 rpm, and a crystal was crystallized for 0.5 h to obtain crystal 1;

[0049] (2) re-dissolving crystal 1 in water to obtain solution A with a concentration of 250 g / L, and controlling the temperature at 40° C.;

[0050] (3) methanol is added to solution A, the temperature is kept constant, and stirring is carried out at a rotating speed of 200 rpm simultaneously, until there is crystal precipitation, crystal preservation 0.5h, methanol is continued to be added, and the total consumption of adding methanol twice is 3.5 times of solution A volume, the temperature is kept constant, and the crystal is cultivated 0.5, and then gradient cooling, 10 DEG C of cooling is lowered every 1h, and it is cooled to 25 DEG C, and crystals are collected by filtration, and after drying in a 50 DEG C baking oven, the thioneine crystal is obtained.

[0051] The purity of the ergothioneine crystals is 99.97%, and the yield is 90%.

[0052] Example 2

[0053] A low-odor, high-stability ergothioneine crystal, the preparation method of the ergothioneine crystal is:

[0054] (1) thioneine crude product is dissolved in water to prepare 150g / L thioneine crude product solution, anhydrous ethanol is added (the addition amount of anhydrous ethanol is 6.5 times of the volume of thioneine crude product solution), temperature is controlled at 50 DEG C, stirred at 800rpm rotating speed simultaneously, carry out primary crystallization, crystal preservation 1.5h, obtain crystal 1;

[0055] (2) re-dissolving crystal 1 in water to obtain solution A with a concentration of 500 g / L, and controlling the temperature at 80° C.;

[0056] (3) Add anhydrous ethanol to solution A, keep the temperature constant, and stir at 500 rpm until crystals precipitate. Keep the crystals for 2.5 hours, continue to add anhydrous ethanol, and the total amount of anhydrous ethanol added twice is 6.5 times the volume of solution A. Keep the temperature constant and grow the crystals for 3 hours. Then, gradually reduce the temperature by 10°C every hour until the temperature reaches 50°C. Filter and collect the crystals, and dry them in an oven at 80°C.

[0057] The purity of the ergothioneine crystals is 99.99%, and the yield is 92%.

[0058] Example 3

[0059] A low-odor, high-stability ergothioneine crystal with Figure 2 The scanning electron micrographs and Figure 7 The powder X-ray diffraction pattern measured using Cu-Kα radiation is shown.

[0060] The preparation method of the ergothioneine crystal is:

[0061] (1) the crude thioneine product was dissolved in water to prepare a crude thioneine solution of 110 g / L, methanol was added (the amount of methanol added was 3.5 times the volume of the crude thioneine solution), the temperature was controlled at 35 ° C, stirred at a rotating speed of 600 rpm, and a crystal was obtained for 1 h.

[0062] (2) re-dissolving crystal 1 in water to obtain solution A with a concentration of 400 g / L, and controlling the temperature at 60° C.;

[0063] (3) Add methanol to solution A, keep the temperature constant, and stir at 350 rpm until crystals precipitate. Keep the crystals for 1.5 h, continue to add methanol, and the total amount of methanol added twice is 5 times the volume of solution A. Keep the temperature constant and grow the crystals for 2 h. Then gradually reduce the temperature by 10°C every hour until the temperature reaches 35°C. Filter and collect the crystals, and dry them in an oven at 70°C.

[0064] The purity of the ergothioneine crystals is 99.98%, and the yield is 91.5%.

[0065] Example 4

[0066] A low-odor, high-stability ergothioneine crystal with Figure 3 The scanning electron micrographs and Figure 8 The powder X-ray diffraction pattern measured using Cu-Kα radiation is shown.

[0067] The preparation method of the ergothioneine crystal is:

[0068] (1) the crude thioneine product was dissolved in water to prepare a crude thioneine solution of 120 g / L, methanol was added (the amount of methanol added was 3 times the volume of the crude thioneine solution), the temperature was controlled at 30 ° C, stirred at a rotating speed of 500 rpm, and a crystal was obtained for 1 h.

[0069] (2) crystal 1 is redissolved in the crude thioneine solution of step (1), and a solution A having a concentration of 350 g / L is obtained, and temperature is controlled at 70 ° C;

[0070] (3) Add methanol to solution A, keep the temperature constant, and stir at 300 rpm until crystals precipitate. Keep the crystals for 2 h, continue to add methanol, and the total amount of methanol added twice is 5.5 times the volume of solution A. Keep the temperature constant and grow the crystals for 1.5 h. Then, gradually reduce the temperature by 10°C every hour until the temperature reaches 40°C. Filter and collect the crystals, and dry them in an oven at 60°C.

[0071] The purity of the ergothioneine crystals is 99.96%, and the yield is 92.5%.

[0072] Comparative Example 1

[0073] The only difference from Example 3 is that the concentration of solution A in step (2) is different, which is 200 g / L, and the other conditions are the same.

[0074] The purity of the ergothioneine crystals is 99.99%, and the yield is 85%.

[0075] Comparative Example 2

[0076] The only difference from Example 3 is that the concentration of solution A in step (2) is different, which is 600 g / L, and the other conditions are the same.

[0077] The purity of the ergothioneine crystals was 95.96%, and the yield was 91.2%.

[0078] Comparative Example 3

[0079] The difference with Example 3 is only that the total consumption of adding methanol twice in step (3) is 3 times of solution A volume, and all the other conditions are all the same. The purity of thioneine crystal is 98.24%, and yield is 85%.

[0080] Comparative Example 4

[0081] The difference with Example 3 is only that the total consumption of adding methanol twice in step (3) is 7 times of solution A volume, and all the other conditions are all the same. The purity of thioneine crystal is 94.15%, and yield is 91.5%.

[0082] Comparative Example 5

[0083] Compared with Example 3, only one crystallization is performed, that is, the one crystallization sample obtained in step (1) of Example 3 has Figure 4 SEM images shown.

[0084] Effect test

[0085] Test Example 1 Moisture absorption test

[0086] The testing method is: select 10 new 20mL glass bottles, fill embodiment 1-4, comparative example 1-5 and commercially available thioneine crystals respectively, clean and place in 105 DEG C of oven drying to constant weight, and do a good job of numbering and recording gram weight; After the embodiment and comparative example samples and commercially available products are dried to constant weight, 1g of powder is filled in a glass bottle respectively, and placed in a constant temperature and humidity chamber (room temperature, 95% humidity); The sample is weighed every 24h until the sample is constant weight; The moisture absorption rate is then calculated, and the results are shown in Table 2. The scanning electron microscope image of commercially available thioneine crystals is as shown in Table 2. Figure 5 , the powder X-ray diffraction pattern is as follows Fig.10 The following test examples are all tested using this commercially available product.

[0087] Table 2 Moisture absorption test results

[0088]

[0089] Test Example 2XRD Detection

[0090] Testing equipment and number: D / max2500 / PC rotating target X-ray diffractometer;

[0091] Testing basis: "Chinese Pharmacopoeia" 2015 Part IV 0451 X-ray diffraction method.

[0092] Example 1 Test results are as follows Figure 6 As shown, the test results of Example 3 and Example 4 are as follows Figure 7 , Figure 8 As shown, the test results of Comparative Example 5 are as follows Fig. 9 As shown, the test results of commercially available products are as follows Fig.10 shown.

[0093] Test Example 3 Odor Detection and Light Stability Detection

[0094] Testing method is: first different thioneine samples are dried to constant weight, and the transparent glass bottle (with lid) of 20mL is dried to constant weight, and the content of thioneine is tested synchronously, and 3 parallels are arranged in each group;

[0095] Weigh 1g of sample powder into a glass bottle, judge whether the initial sample has taste, and record;

[0096] Transfer to sunlight (on the office balcony) and evaluate the taste after exposure to sunlight for 1 and 2 weeks;

[0097] After 4 weeks of illumination, the ergothioneine content in the powder was tested again to check the retention rate of ergothioneine.

[0098] Taste evaluation method: The sample is in a bottle with a cover. After the light exposure is completed, the bottle cover is opened and people put their noses close to smell the odor. Each group requires 5 people to make the evaluation.

[0099] Ergothioneine powder retention rate test method:

[0100] 1) thioneine powder before initial illumination is dried to constant weight, 0.1g powder is weighed, dissolved in 100mL water, the concentration a1 of thioneine is tested, and then the content of thioneine is converted into: content=a1 / 1*100%;

[0101] 2) content after illumination 4 weeks: thioneine powder after illumination 4 weeks is dried to constant weight, 0.1g powder is weighed, dissolved in 100mL water, the concentration a2 of thioneine is tested, and then converted to the content of thioneine: content=a2 / 1*100%;

[0102] 3) 4-week light retention rate: =(a1-a2) / a1*100%.

[0103] The test results are shown in Table 3.

[0104] Table 3 Odor detection and light stability test results

[0105]

[0106] Test Example 4 Thermogravimetric Analysis

[0107] Temperature range: room temperature to 800°C; temperature control speed: 10°C / min; atmosphere: nitrogen atmosphere.

[0108] Example 3 Test results are as follows Fig.11 As shown in Figure 2, the maximum weight loss temperature is 304.06°C. The test results of commercially available products are as follows: Fig.12 As shown, the maximum weight loss temperature is 299.93° C. The maximum weight loss temperatures of the crystal samples of various embodiments of the present invention are all higher than those of commercially available products, indicating that the crystal samples of the present invention have good thermal stability.

[0109] Test Example 5 Melting Point Test

[0110] The present invention refers to GB / T 617-2006 4.2 to determine the melting point of thioneine crystals. The melting point / melting range measured in Example 3 is 275-277°C.

[0111] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A low-smell, high-stability ergothioneine crystal, characterized in that, The ergothioneine crystal uses Cu-Kα radiation, and the X-ray diffraction spectrum represented by 2θ is at least 9.50±0.2°, 14.46±0.2°, 15.52±0.2°, 16.10±0.2°, 17.32±0.2°, 19.06±0.2°, 20.50±0.2°, 21.26±0.2°, 22.28±0.2°, 23.98±0.2°, 24.88±0.2°, 25.48±0.2°, 25.92±0.2°, 26. .40±0.2°, 28.74±0.2°, 29.22±0.2°, 29.86±0.2°, 30.26±0.2°, 30.72±0.2°, 32.26±0.2°, 32.76±0.2°, 34.66±0.2°, 35.10±0.2°, 35.68±0.2°, 36.56±0.2°, 36.98±0.2°, 37.96±0.2°, 38.62±0.2°, and 39.24±0.2° have characteristic peaks.

2. ergothioneine crystal according to claim 1, is characterized in that, The maximum weight loss temperature of the ergothioneine crystal is 304.06°C.

3. ergothioneine crystal according to claim 1, is characterized in that, The melting point of the ergothioneine crystal is 275-277°C.

4. ergothioneine crystal according to claim 1, is characterized in that, The preparation method of described ergothioneine crystal is as follows: (1) dissolving crude thioneine in water to prepare a 110 g / L crude thioneine solution, adding methanol, wherein the amount of methanol added is 3.5 times the volume of the crude thioneine solution, controlling the temperature at 35° C., stirring at a speed of 600 rpm, performing a primary crystallization, and preserving the crystal for 1 hour to obtain crystal 1; (2) Redissolving crystal 1 in water to obtain solution A with a concentration of 400 g / L and controlling the temperature at 60°C; (3) Add methanol to solution A, keep the temperature constant, and stir at 350 rpm until crystals precipitate. Keep the crystals for 1.5 h, continue to add methanol, and the total amount of methanol added twice is 5 times the volume of solution A. Keep the temperature constant and grow the crystals for 2 h. Then gradually reduce the temperature by 10°C every hour until the temperature reaches 35°C. Filter and collect the crystals, and dry them at 70°C.

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