Low-odor and high-stability ergothioneine crystal

Abstract

The present application belongs to the technical field of compound crystals, and specifically relates to a low-odor and high-stability ergothioneine crystal. An X-ray diffraction pattern, which is collected using Cu-Kα radiation and plotted against 2θ, of the ergothioneine crystal at least has characteristic peaks at 9.50±0.2º, 15.52±0.2º, 19.06±0.2º, 24.88±0.2º, 25.48±0.2º, 28.74±0.2º, 29.22±0.2º and 35.10±0.2º. The new crystal form of ergothioneine in the present application exhibits good light stability, good moisture absorption resistance, and also a high decomposition temperature.

Description

Low-odor and high-stability ergothioneine crystal TECHNICAL FIELD

[0001] The application belongs to the technical field of compound crystals and particularly relates to a low-odor and high-stability ergothioneine crystal. BACKGROUND

[0002] Ergothioneine (mercaptohistidine trimethyl inner salt, EGT) is a white crystal in pure form, with a molecular formula of C9H 15 N3O2S and a molecular weight of 229.09.

[0003] Ergothioneine has super strong antioxidant capacity and can protect cells in the human body, and 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 isomer forms of thiol and thione, specifically as follows:

[0005] Under light conditions, ergothioneine can be degraded and has a smell of trimethylamine. Meanwhile, the moisture resistance of ergothioneine needs to be improved.

[0006] CN118221592A discloses an ergothioneine crystal and a preparation method thereof. The preparation method provided therein includes the following steps: stirring 98.0%-99.9% pure crude ergothioneine in warm water at 30-40°C until it is dissolved, then cooling at 5-10°C, and standing to obtain the ergothioneine crystal. However, the moisture resistance and light stability of the product are not concerned.

[0007] Currently, there is no prior art that discloses a new ergothioneine crystal that can improve moisture resistance and light stability.

[0008] Therefore, it is particularly important to develop a crystal form that is more resistant to light, more stable, and less prone to moisture absorption. SUMMARY

[0009] The application provides a low-odor and high-stability ergothioneine crystal.

[0010] In one aspect, the application provides a low-odor and high-stability ergothioneine crystal. The ergothioneine crystal has an X-ray diffraction spectrum expressed in 2θ using Cu-Kα radiation, and has characteristic peaks 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°.

[0011] Preferably, the ergothioneine crystal has X-ray diffraction spectrum further having characteristic peaks at 16.10±0.2°, 17.32±0.2°, 20.50±0.2°, 23.98±0.2°, 26.40±0.2°, 38.62±0.2°, using Cu-Ka radiation, expressed in 2θ.

[0012] Further preferably, the ergothioneine crystal has X-ray diffraction spectrum further having 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°, using Cu-Ka radiation, expressed in 2θ.

[0013] Preferably, the ergothioneine crystal has X-ray powder diffraction pattern (Cu-Ka) as shown in Figure 7 and Table 1.

[0014] Table 1 Main XRD peaks of ergothioneine crystal

[0015] Preferably, the ergothioneine crystal has maximum weight loss temperature of 302-305°C.

[0016] Preferably, the ergothioneine crystal has melting point of 275-277°C.

[0017] Preferably, the method for preparing the ergothioneine crystal comprises the following steps:

[0018] (1) mixing crude ergothioneine with water to prepare a crude solution of 70-150 g / L, adding ethanol or methanol, crystallizing to obtain crystal 1;

[0019] (2) mixing crystal 1 with water-containing solvent to prepare solution A of 250-500 g / L;

[0020] (3) adding ethanol or methanol to solution A until crystals precipitate, maintaining the crystals, continuously adding ethanol or methanol, crystallizing, cooling, filtering, and drying to obtain the ergothioneine crystal.

[0021] Further preferably, in step (1), the amount of ethanol or methanol added is 3-7 times the volume of the crude solution, the crystallization temperature is 20-50°C, the crystallization time is 0.5-1.5 h, and the crystallization is performed simultaneously with stirring at a speed of 300-800 rpm.

[0022] Further preferably, the aqueous solvent in step (2) comprises water or the crude 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.

[0023] Further preferably, the temperature after adding ethanol or methanol in step (3) is controlled at 40-80℃, the time for crystal growth is 0.5-2.5h, before the crystal precipitates, stirring is performed at a speed of 200-500rpm while adding ethanol or methanol; the time for crystal growth is 0.5-3h, the temperature is lowered in a gradient manner, i.e. lowering the temperature by 10℃ per hour until the temperature is lowered to 25-50℃, and the drying temperature is 50-80℃.

[0024] In another aspect, the present application also relates to the use of the above ergothioneine crystal in the preparation of food, health products, cosmetics or pharmaceuticals.

[0025] Compared with the prior art, the present application has the following beneficial effects:

[0026] (1) The present application optimizes the concentration of the solution in the secondary crystallization process, and finally prepares a new crystal form of ergothioneine which has excellent light stability, good moisture resistance and high decomposition temperature.

[0027] (2) The present application optimizes the amount of alcohol solvent in the secondary crystallization process, which not only ensures good light stability and moisture resistance, but also improves the purity and yield of the product. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a scanning electron microscope image of the new crystal form of ergothioneine in Example 1.

[0029] Figure 2 is a scanning electron microscope image of the new crystal form of ergothioneine in Example 3.

[0030] Figure 3 is a scanning electron microscope image of the new crystal form of ergothioneine in Example 4.

[0031] Figure 4 is a scanning electron microscope image of the new crystal form of ergothioneine in Comparative Example 5.

[0032] Figure 5 is a scanning electron microscope image of a commercially available ergothioneine product.

[0033] Figure 6 is a powder X-ray diffraction pattern of the new crystal form of ergothioneine in Example 1.

[0034] Figure 7 is a powder X-ray diffraction pattern of the new crystal form of ergothioneine in Example 3.

[0035] Figure 8 is a powder X-ray diffraction pattern of the new crystal form of ergothioneine in Example 4.

[0036] Figure 9 is a powder X-ray diffraction pattern of the new crystal form of ergothioneine in Comparative Example 5.

[0037] Figure 10 is a powder X-ray diffraction pattern of a commercially available ergothioneine product.

[0038] Figure 11 is a thermogravimetric analysis pattern of the ergothioneine new crystal form of Example 3.

[0039] Figure 12 is a thermogravimetric analysis pattern of a commercially available ergothioneine product. DETAILED DESCRIPTION

[0040] The present application will be further described in conjunction with specific examples, which are not intended to limit the present application, but merely to illustrate the present application. The experimental methods used in the following examples are not specifically indicated, and the experimental methods not specifically indicated in the examples are generally performed under conventional conditions. The materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

[0041] Example 1

[0042] The present example provides a low-odor, high-stability ergothioneine crystal having the scanning electron microscope pattern shown in Figure 1 and the powder X-ray diffraction pattern measured using Cu-Ka rays shown in Figure 6.

[0043] The preparation method of the ergothioneine crystal is as follows:

[0044] (1) The crude ergothioneine was dissolved in water to prepare a crude ergothioneine solution of 70 g / L, methanol was added (the amount of methanol added was 5 times the volume of the crude ergothioneine solution), the temperature was controlled at 20°C, and stirring was performed at a speed of 300 rpm, and a first crystallization was performed, the crystal was maintained for 0.5 h, and crystal 1 was obtained;

[0045] (2) Crystal 1 was redissolved in water to obtain solution A with a concentration of 250 g / L, and the temperature was controlled at 40°C;

[0046] (3) Methanol was added to solution A while maintaining the temperature, and stirring was performed at a speed of 200 rpm until crystals precipitated, the crystals were maintained for 0.5 h, methanol was continuously added, the total amount of methanol added was 3.5 times the volume of solution A, the temperature was maintained, the crystals were maintained for 0.5 h, and then the temperature was gradually decreased by 10°C every 1 h until the temperature reached 25°C, the crystals were collected by filtration, and the crystals were dried in an oven at 50°C to obtain the ergothioneine crystal.

[0047] The purity of the ergothioneine crystal was 99.97%, and the yield was 90%.

[0048] Example 2

[0049] The present example provides a low-odor, high-stability ergothioneine crystal, and the preparation method of the ergothioneine crystal is as follows:

[0050] (1) The crude ergothioneine was dissolved in water to prepare a crude ergothioneine solution with a concentration of 150 g / L, anhydrous ethanol was added (the amount of anhydrous ethanol added was 6.5 times the volume of the crude ergothioneine solution), the temperature was controlled at 50°C, and stirring was performed at a speed of 800 rpm to perform a first crystallization, the crystals were maintained for 1.5 h to obtain crystals 1;

[0051] (2) The crystals 1 were redissolved in water to obtain solution A with a concentration of 500 g / L, and the temperature was controlled at 80°C;

[0052] (3) Anhydrous ethanol was added to solution A while maintaining the temperature, and stirring was performed at a speed of 500 rpm until crystals precipitated, the crystals were maintained for 2.5 h, anhydrous ethanol was continuously added, the total amount of anhydrous ethanol added was 6.5 times the volume of solution A, the temperature was maintained, the crystals were maintained for 3 h, the temperature was then gradually reduced by 10°C every 1 h until the temperature reached 50°C, the crystals were collected by filtration, and the crystals were dried in an oven at 80°C to obtain the ergothioneine crystals.

[0053] The purity of the ergothioneine crystals was 99.99%, and the yield was 92%.

[0054] Example 3

[0055] The ergothioneine crystals provided in this example have a low odor and high stability, and have a scanning electron microscope image as shown in FIG. 2 and a powder X-ray diffraction pattern measured using Cu-Kα rays as shown in FIG. 7.

[0056] The preparation method of the ergothioneine crystals is as follows:

[0057] (1) The crude ergothioneine was dissolved in water to prepare a crude ergothioneine solution with a concentration of 110 g / L, methanol was added (the amount of methanol added was 3.5 times the volume of the crude ergothioneine solution), the temperature was controlled at 35°C, and stirring was performed at a speed of 600 rpm to perform a first crystallization, the crystals were maintained for 1 h to obtain crystals 1;

[0058] (2) The crystals 1 were redissolved in water to obtain solution A with a concentration of 400 g / L, and the temperature was controlled at 60°C;

[0059] (3) Methanol was added to solution A while maintaining the temperature, and stirring was performed at a speed of 350 rpm until crystals precipitated, the crystals were maintained for 1.5 h, methanol was continuously added, the total amount of methanol added was 5 times the volume of solution A, the temperature was maintained, the crystals were maintained for 2 h, the temperature was then gradually reduced by 10°C every 1 h until the temperature reached 35°C, the crystals were collected by filtration, and the crystals were dried in an oven at 70°C to obtain the ergothioneine crystals.

[0060] The purity of the ergothioneine crystals was 99.98%, and the yield was 91.5%.

[0061] Example 4

[0062] The embodiment provides a low-odor and high-stability ergothioneine crystal, which has a scanning electron microscope image shown in Figure 3 and a powder X-ray diffraction pattern measured by Cu-Kα ray shown in Figure 8.

[0063] The preparation method of the ergothioneine crystal is as follows:

[0064] (1) The crude ergothioneine is dissolved in water to prepare a crude ergothioneine solution with a concentration of 120 g / L, methanol is added (the amount of methanol is 3 times the volume of the crude ergothioneine solution), the temperature is controlled at 30°C, and stirring is performed at a speed of 500 rpm, one-time crystallization is performed, and the crystals are preserved for 1 h to obtain crystal 1;

[0065] (2) The crystal 1 is redissolved in the crude ergothioneine solution of step (1) to obtain a solution A with a concentration of 350 g / L, and the temperature is controlled at 70°C;

[0066] (3) Methanol is added to the solution A, the temperature is kept unchanged, and stirring is performed at a speed of 300 rpm until crystals are precipitated, the crystals are preserved for 2 h, methanol is continuously added, the total amount of methanol added is 5.5 times the volume of the solution A, the temperature is kept unchanged, the crystals are preserved for 1.5 h, then gradient cooling is performed, the temperature is lowered by 10°C every 1 h, and the temperature is lowered to 40°C, the crystals are collected by filtration, and the crystals are dried in an oven at 60°C to obtain the ergothioneine crystal.

[0067] The purity of the ergothioneine crystal is 99.96%, and the yield is 92.5%.

[0068] Comparative Example 1

[0069] The difference between the comparative example and the embodiment 3 is only that the concentration of the solution A in step (2) is 200 g / L, and the other conditions are the same.

[0070] The purity of the ergothioneine crystal is 99.99%, and the yield is 85%.

[0071] Comparative Example 2

[0072] The difference between the comparative example and the embodiment 3 is only that the concentration of the solution A in step (2) is 600 g / L, and the other conditions are the same.

[0073] The purity of the ergothioneine crystal is 95.96%, and the yield is 91.2%.

[0074] Comparative Example 3

[0075] The difference between the comparative example and the embodiment 3 is only that the total amount of methanol added in step (3) is 3 times the volume of the solution A, and the other conditions are the same.

[0076] The purity of the ergothioneine crystal was 98.24%, and the yield was 85%.

[0077] Comparative Example 4

[0078] The only difference between this comparative example and Example 3 was that the total amount of methanol added in step (3) was 7 times the volume of solution A, and the other conditions were the same.

[0079] The purity of the ergothioneine crystal was 94.15%, and the yield was 91.5%.

[0080] Comparative Example 5

[0081] The only difference between this comparative example and Example 3 was that only one crystallization was performed, i.e., the once-crystallized sample obtained in step (1) of Example 3, which had a scanning electron microscope image shown in Figure 4.

[0082] Effect Test

[0083] Test Example 1 Hygroscopicity Test

[0084] The test method was as follows: 10 new 20 mL glass bottles were selected, and were respectively filled with the ergothioneine crystals of Examples 1-4, Comparative Examples 1-5, and a commercially available ergothioneine crystal. The glass bottles were washed, placed in an oven at 105°C, and dried to a constant weight, and the number and weight were recorded. After the samples of Examples and Comparative Examples and the commercially available product were dried to a constant weight, 1 g of powder was respectively filled into the glass bottles and placed in a constant temperature and humidity chamber (room temperature, 95% humidity). The samples were weighed every 24 h until the weight was constant. Then the hygroscopicity was calculated, and the results are shown in Table 2. The scanning electron microscope image of the commercially available ergothioneine crystal is shown in Figure 5, and the powder X-ray diffraction pattern is shown in Figure 10. The commercially available product was used for testing in the following test examples.

[0085] Table 2 Hygroscopicity Test Results

[0086] Test Example 2 XRD Test

[0087] Test equipment and number: D / max2500 / PC type rotating target X-ray diffractometer

[0088] Test basis: X-ray Diffraction Method, 0451, Chinese Pharmacopoeia 2015, Volume 4.

[0089] The test results of Example 1 are shown in Figure 6, the test results of Example 3 and Example 4 are shown in Figures 7 and 8, the test results of Comparative Example 5 are shown in Figure 9, and the test results of the commercially available product are shown in Figure 10.

[0090] Test Example 3 Odor Test and Light Stability Test

[0091] The test method is: first, different ergothioneine samples are dried to constant weight, 20 mL of transparent glass bottle (with cover) is dried to constant weight, and the content of ergothioneine is tested synchronously, 3 parallel samples for each group;

[0092] 1g of sample powder is weighed into a glass bottle, and whether the initial sample has a smell is judged, and the result is recorded;

[0093] Transfer to sunlight (on the balcony of the office), and evaluate the smell after 1 week and 2 weeks of illumination;

[0094] After 4 weeks of illumination, the content of ergothioneine in the powder is tested again to check the retention rate of ergothioneine.

[0095] The smell evaluation method is: the sample is a bottle with a cover, after the illumination is completed, the cover is opened, and the smell is smelled by the nose, and 5 people are needed for evaluation in each group.

[0096] Ergothioneine powder retention rate test method:

[0097] 1) The initial ergothioneine powder before illumination is dried to constant weight, 0.1g of powder is weighed, dissolved in 100mL of water, the concentration a1 of ergothioneine is tested, and then the content of ergothioneine is converted: content = a1 / 1*100%;

[0098] 2) Content after 4 weeks of illumination: The ergothioneine powder after 4 weeks of illumination is dried to constant weight, 0.1g of powder is weighed, dissolved in 100mL of water, the concentration a2 of ergothioneine is tested, and then the content of ergothioneine is converted: content = a2 / 1*100%;

[0099] 3) 4 weeks of illumination retention rate: = (a1-a2) / a1*100%.

[0100] The test results are shown in Table 3.

[0101] Table 3: Results of odor detection and light stability detection

[0102] Test Example 4: Thermogravimetric Analysis

[0103] Temperature range: room temperature to 800℃; temperature control speed: 10℃ / min; atmosphere: nitrogen atmosphere.

[0104] The test results of Example 3 are shown in Figure 11, and the maximum weight loss temperature is 304.06℃. The test results of the commercially available product are shown in Figure 12, and the maximum weight loss temperature is 299.93℃. The maximum weight loss temperature of the crystal samples of each embodiment of the present application is higher than that of the commercially available product, indicating that the crystal samples of the present application have good thermal stability.

[0105] Test Example 5: Melting Point Test

[0106] The determination of the melting point of ergothioneine crystals was performed according to GB / T 617-2006 4.2. The melting point / melting range measured in Example 3 was 275-277°C.

[0107] The above detailed description is a specific description of one of the possible embodiments of the present application, which is not intended to limit the patent scope of the present application, and any equivalent implementation or change made without departing from the present application shall be included in the scope of the technical solutions of the present application.

Claims

1. A low-odour, high-stability ergothioneine crystal, wherein, The X-ray diffraction spectrum of the ergothioneine crystal has characteristic peaks at 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°, 39.24±0.2°, using Cu-Kα radiation, expressed in 2θ.

2. The ergothioneine crystal according to claim 1, wherein, The maximum weight loss temperature of the ergothioneine crystal is 304.06℃.

3. The ergothioneine crystal of claim 1, wherein, The melting point of the ergothioneine crystal is 275-277℃.

4. The ergothioneine crystal of claim 1, wherein, The preparation method of the ergothioneine crystal is as follows: (1) The crude ergothioneine is dissolved in water to prepare a crude ergothioneine solution with a concentration of 110 g / L, methanol is added, the amount of methanol added is 3.5 times the volume of the crude ergothioneine solution, the temperature is controlled at 35℃, and stirring is carried out at a speed of 600 rpm, once crystallization is carried out, the crystal is preserved for 1 h, and crystal 1 is obtained; (2) Crystal 1 is redissolved in water to obtain solution A with a concentration of 400 g / L, and the temperature is controlled at 60℃; (3) Methanol is added to solution A, the temperature is kept unchanged, and stirring is carried out at a speed of 350 rpm until crystals are precipitated, the crystals are preserved for 1.5 h, methanol is continuously added, the total amount of methanol added is 5 times the volume of solution A, the temperature is kept unchanged, the crystals are preserved for 2 h, then the temperature is gradually reduced by 10℃ per hour, the temperature is reduced to 35℃, the crystals are collected by filtration, and are dried at 70℃ to obtain the ergothioneine crystal.

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