Salt of leucine dipeptide

Abstract

Disclosed are a physiologically acceptable salt of leucine dipeptide and a preparation method therefor. The present invention provides a method for enabling the efficient and stable production of the salt of leucine dipeptide; the salt of the present invention can have wider application prospects in the fields such as dietary supplements and food.

Description

Salt of leucine dipeptide Technical Field

[0001] The present invention relates to physiologically acceptable salts of leucine dipeptide and methods for preparing the same. Background Art

[0002] Leucine dipeptide is a dipeptide formed by a peptide bond between two L-leucine amino acids. It is increasingly recognized that leucine dipeptide has numerous physiological activities, such as fat loss and muscle growth, and has many health benefits. It has broad application prospects in dietary supplements, food, medicine, and other fields.

[0003] However, despite its numerous health benefits, leucine dipeptide faces several technical bottlenecks in its practical application. Leucine dipeptide's low solubility limits its use in dosage forms such as liquid foods, beverages, oral solutions, or injections. Low solubility not only affects its bioavailability but can also lead to poor product stability, unpleasant taste, or inconvenience, reducing consumer acceptance and thus hindering its application. Avoiding these issues and enabling its wider application remains a key area of ​​research for those skilled in the art. Summary of the Invention

[0004] The present invention can prepare a stable physiologically acceptable salt of leucine dipeptide, which has the advantages of low energy consumption and material consumption, and the leucine dipeptide salt of the present invention can be better applied in the fields of dietary supplements, food and the like.

[0005] In one aspect, the present invention provides a physiologically acceptable salt of leucine dipeptide, wherein the salt is selected from one or more of sodium salt, potassium salt, calcium salt, and magnesium salt.

[0006] In some embodiments, the molar ratio of leucine dipeptide to metal is 1: 1 to 2: 1. In some embodiments, the molar ratio of leucine dipeptide to metal is 1: 1, 2: 1.

[0007] In some embodiments, the salt is in a crystalline form, an amorphous form, or a mixture thereof.

[0008] In some embodiments, the X-ray powder diffraction pattern of sodium leucine dipeptide comprises peaks at diffraction angles (2θ) of 5.53°±0.20°, 6.23±0.20°, 13.30±0.20°, and 22.80±0.20°.

[0009] In some embodiments, the X-ray powder diffraction pattern of sodium leucine dipeptide further comprises one or more peaks at diffraction angles (2θ) of 7.27±0.20°, 17.83±0.20°, and 29.37±0.20°.

[0010] In some embodiments, the X-ray powder diffraction pattern of sodium leucine dipeptide further comprises one or more peaks at diffraction angles (2θ) of 10.05±0.20°, 17.29±0.20°, and 18.79±0.20°.

[0011] In some embodiments, the X-ray powder diffraction pattern of sodium leucine dipeptide is as shown in FIG1 .

[0012] In some embodiments, the infrared spectrum of sodium leucine dipeptide has the following absorption bands, expressed as the inverse of the wavelength (cm -1 )(±2cm -1 ): 3314, 2955, 2870, 1634, 1597, 1531, 1468, 1400, 1366, 1163, 932, 868, 833, 766, 517, 469.

[0013] In some embodiments, the X-ray powder diffraction pattern of potassium dipeptide leucine includes peaks at diffraction angles (2θ) of 5.24°±0.20°, 9.35°±0.20°, 18.58°±0.20°, and 22.05°±0.20°.

[0014] In some embodiments, the X-ray powder diffraction pattern of potassium dipeptide leucine further comprises one or more peaks at diffraction angles (2θ) of 6.53°±0.20°, 10.77°±0.20°, and 26.96°±0.20°.

[0015] In some embodiments, the X-ray powder diffraction pattern of potassium dipeptide leucine further comprises one or more peaks at diffraction angles (2θ) of 7.38°±0.20°, 16.10°±0.20°, and 19.34°±0.20°.

[0016] In some embodiments, the X-ray powder diffraction pattern of potassium dipeptide leucine is as shown in FIG2 .

[0017] In some embodiments, the infrared spectrum of potassium dipeptide leucine has the following absorption bands, expressed as the inverse of the wavelength (cm -1 )(±2cm -1 ): 3314, 2955, 2868, 1639, 1589, 1522, 1468, 1391, 1364, 1161, 1138, 930, 866, 756, 565, 517, 471.

[0018] In some embodiments, the X-ray powder diffraction pattern of leucine dipeptide calcium includes peaks at diffraction angles (2θ) of 4.53°±0.20°, 6.11°±0.20°, 13.47°±0.20°, and 17.88°±0.20°.

[0019] In some embodiments, the X-ray powder diffraction pattern of leucine dipeptide calcium further comprises one or more peaks at diffraction angles (2θ) of 5.32°±0.20°, 9.01°±0.20°, and 19.44°±0.20°.

[0020] In some embodiments, the X-ray powder diffraction pattern of leucine dipeptide calcium further comprises one or more peaks at diffraction angles (2θ) of 7.07°±0.20°, 14.44°±0.20°, and 24.58°±0.20°.

[0021] In some embodiments, the X-ray powder diffraction pattern of leucine dipeptide calcium is as shown in FIG3 .

[0022] In some embodiments, the infrared spectrum of calcium leucine dipeptide has the following absorption bands, expressed as the inverse of the wavelength (cm -1 )(±2cm -1 ): 3339, 2957, 2870, 1639, 1593, 1574, 1470, cm -1 、1423、1387、1368、1169、868、579。

[0023] In some embodiments, the magnesium dipeptide leucine has an X-ray powder diffraction pattern comprising peaks at diffraction angles (2θ) of 6.23°±0.20° and 18.25°±0.20°.

[0024] In some embodiments, the X-ray powder diffraction pattern of leucine dipeptide magnesium is as shown in FIG4 .

[0025] In some embodiments, the infrared spectrum of magnesium leucine dipeptide has the following absorption bands, expressed as the inverse of the wavelength (cm -1 )(±2cm -1 ): 2957, 2870, 1636, 1526, 1470, 1420, 1387, 1368, 1169.

[0026] In another aspect, the present invention provides a method for preparing the salt as described above, comprising: reacting leucine dipeptide with an alkaline metal compound; concentrating, adding a solvent, heating, and dissolving; cooling to precipitate a solid, and drying to obtain the salt.

[0027] In some embodiments, the basic metal compound is selected from one or more of the following: oxides, peroxides, hydrides, hydroxides, and organic metal bases of sodium, potassium, calcium, and magnesium. In some embodiments, the organic metal base includes methoxide, ethoxide, and the like.

[0028] In some embodiments, the solvent is selected from one or more of the following: methanol, ethanol, propanol, isopropanol, butanol, acetonitrile, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, isopropyl acetate, and water.

[0029] In some embodiments, the temperature is raised to 40-80°C.

[0030] In some embodiments, the salt is used in the preparation of a food, a beverage, a supplement, or a nutraceutical.

[0031] In another aspect, the present invention provides a composition comprising the salt as described above, and a leucine dipeptide.

[0032] In some embodiments, the physiologically acceptable salt of the leucine dipeptide and the composition of the leucine dipeptide have a proportion of the physiologically acceptable salt of the leucine dipeptide greater than 55%. In some embodiments, the proportion of the salt is greater than 60%, 65%, 70%, 75%, 80%, 90%, or 99%.

[0033] In some embodiments, the composition further comprises a physiologically acceptable carrier.

[0034] In some embodiments, the composition is used to prepare a food, a beverage, a supplement, or a nutraceutical.

[0035] Compared with the prior art, the present invention can efficiently and stably produce the salt of leucine dipeptide; and the leucine dipeptide salt of the present invention has good stability and better solubility, and can have a wider application prospect in the fields of dietary supplements, food and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG1 is an XRPD diagram of sodium leucine dipeptide of the present invention.

[0037] FIG2 is an XRPD pattern of leucine dipeptide potassium of the present invention.

[0038] FIG3 is an XRPD pattern of leucine dipeptide calcium of the present invention.

[0039] FIG4 is an XRPD pattern of leucine dipeptide magnesium of the present invention.

[0040] FIG5 is an infrared spectrum (IR) of sodium leucine dipeptide of the present invention.

[0041] FIG6 is an infrared spectrum (IR) of leucine dipeptide potassium of the present invention.

[0042] FIG7 is an infrared spectrum (IR) of leucine dipeptide calcium of the present invention.

[0043] FIG8 is an infrared spectrum (IR) of leucine dipeptide magnesium of the present invention.

[0044] FIG9 is a TGA diagram of sodium leucine dipeptide of the present invention.

[0045] FIG10 is a TGA diagram of potassium leucine dipeptide of the present invention.

[0046] FIG11 is a TGA diagram of leucine dipeptide calcium of the present invention.

[0047] FIG12 is a TGA chart of leucine dipeptide magnesium of the present invention.

[0048] FIG13 is a DSC spectrum of sodium leucine dipeptide of the present invention.

[0049] FIG14 is a DSC spectrum of potassium leucine dipeptide of the present invention.

[0050] FIG15 is a DSC spectrum of leucine dipeptide calcium of the present invention.

[0051] FIG16 is a DSC spectrum of leucine dipeptide magnesium of the present invention. DETAILED DESCRIPTION

[0052] The preferred embodiments of the present invention will now be described in detail with reference to the embodiments thereof. Although the present invention will be described in conjunction with the preferred embodiments, it should be understood that they are not intended to limit the present invention to these embodiments. On the contrary, the present invention is intended to cover substitutions, modifications and equivalents, which may be included within the spirit and scope of the present invention as defined in the claims. In addition, in the detailed description of the present invention, many specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that the present invention can be practiced without these specific details. In other cases, well-known methods, procedures, components and other features are not described in detail to avoid unnecessarily obscuring various aspects of the present invention.

[0053] As used herein, the term "or" is intended to include "and" and "or." In other words, the term "or" can also be replaced with "and / or."

[0054] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0055] As used herein, the term "comprises" or "includes" or variations thereof refers to instances where the term is used in its non-limiting sense, meaning that items following the term are included, but items not specifically mentioned are not excluded. It also includes the more restrictive verbs 'consisting essentially of' and 'consisting of.'

[0056] As used herein, the terms "about" and "approximately" provide flexibility in numerical values ​​by providing that a given value may be "slightly higher" or "less than" an endpoint. The flexibility of this term can be determined by the specific variables and is within the knowledge of those skilled in the art to determine based on experience and the relevant description herein.

[0057] As used herein, the term "physiologically acceptable" refers to pharmaceutically, physiologically, dietary, nutritionally acceptable, and refers to those compositions or agents, materials or combinations of compositions and / or dosage forms thereof that are within the scope of sound medical judgment, suitable for contact with human and animal tissues, compatible with other ingredients of the composition, without excessive toxicity, irritation, allergic response or other problems or complications, and commensurate with a reasonable benefit / risk ratio.

[0058] In some embodiments, the salts of the present invention can be prepared as compositions together with dietary or pharmaceutically acceptable carriers. In the present invention, the administration form of the composition is provided and involves liquid or solid fillers, diluents, excipients, solvents or encapsulating materials. Each carrier must be "acceptable" in the sense that it is compatible with the other ingredients of the composition and is harmless to the subject, i.e., suitable for consumption or nutritionally acceptable.

[0059] In some embodiments, the salts of the present invention may be administered with other supplements, such as vitamins, minerals, nootropics, and other supplements known in the art.

[0060] The following examples are illustrative of selected embodiments of the present invention and are not intended to limit the scope of the invention.

[0061] The experimental methods described in the examples are conventional methods unless otherwise specified; the reagents and materials used are commercially available unless otherwise specified.

[0062] Example 1. Preparation of sodium leucine dipeptide

[0063] Leucine dipeptide (50 g, 1.0 eq) and sodium hydroxide (8.2 g, 1.0 eq) were placed in 250 mL of purified water and heated to 50-60°C for 4 h to dissolve completely. The solution was concentrated to remove water, and 100 mL of isopropanol was added and heated to 60°C to dissolve the solution. The solution was then slowly cooled to crystallize, filtered, and dried to obtain 50.5 g of a white solid with a yield of 92.7%.

[0064] Example 2. Preparation of potassium leucine dipeptide

[0065] Preparation 1: Leucine dipeptide (50 g, 1.0 eq) and potassium hydroxide (11.5 g, 1.0 eq) were placed in 250 mL of purified water and heated to 50-60°C for 4 h to dissolve the mixture. The mixture was concentrated to remove the water, and 100 mL of isopropanol was added and heated to 60°C to dissolve the mixture. The mixture was slowly cooled to crystallize, filtered, and dried to obtain 52.4 g of a white solid (90.7% yield).

[0066] Preparation 2: Leucine dipeptide (50 g, 1.0 eq) and potassium peroxide (14.57 g, 1.0 eq) were placed in 250 mL of purified water and heated to 50-60°C for 4 h to dissolve completely. The mixture was concentrated to remove water, and 100 mL of ethanol was added and heated to 50°C to dissolve the clear solution. The mixture was slowly cooled to crystallize, filtered, and dried to obtain 51.5 g of a white solid (89.1% yield).

[0067] Example 3. Preparation of Leucine Dipeptide Calcium

[0068] Preparation 1: Leucine dipeptide (50 g, 1.0 eq) and calcium hydroxide (7.6 g, 0.5 eq) were placed in 250 mL of purified water and heated to 60-70°C for 4 h to dissolve the mixture. The mixture was concentrated to remove the water, and 100 mL of isopropanol was added and heated to 60°C to dissolve the mixture. The mixture was slowly cooled to crystallize, filtered, and dried to obtain 50.1 g of a white solid (92.9% yield).

[0069] Preparation 2: Leucine dipeptide (50 g, 1.0 eq) and calcium oxide (5.7 g, 0.5 eq) were placed in 250 mL of purified water and heated to 60-70°C for 4 h to dissolve completely. The solution was concentrated to remove water, and 100 mL of water was added and heated to 70°C to dissolve the solution. The solution was slowly cooled to crystallize, filtered, and dried to obtain 41.3 g of a white solid (76.6% yield).

[0070] Example 4. Preparation of magnesium leucine dipeptide

[0071] Preparation 1: Leucine dipeptide (50 g, 1.0 eq) and magnesium hydroxide (6.0 g, 0.5 eq) were placed in 250 mL of purified water and heated to 80-90°C for 8 h until completely dissolved. The solution was concentrated to remove the water, and 100 mL of isopropanol was added and heated to 60°C to dissolve the solution. The solution was slowly cooled to crystallize, filtered, and dried to obtain 47.6 g of a white solid (91.1% yield).

[0072] Preparation 2: Leucine dipeptide (50 g, 1.0 eq) and magnesium methoxide (8.8 g, 0.5 eq) were placed in 250 mL of purified water and heated to 40-50°C for 8 h until completely dissolved. The water was concentrated to remove the water, and 100 mL of methanol was added and heated to 60°C to dissolve the solution. The solution was slowly cooled to crystallize, filtered, and dried to obtain 43.4 g of a white solid (83.0% yield).

[0073] Content determination

[0074] For the leucine dipeptide salt of each example, the leucine dipeptide content and the metal ion content were measured, and the results are shown in the following table.

[0075] Solubility

[0076] The solubility of leucine dipeptide and the leucine dipeptide salts of various examples at 20° C. was measured, and the results are shown in the following table.

[0077] X-ray diffraction

[0078] The X-ray powder diffraction pattern was obtained using a SmartLab 3KW X-ray powder diffractometer under the following conditions: diffraction line: Cu_K-beta (40KV, 40mA), scanning rate: 20.00deg / min, scanning range: 5°~40°.

[0079] The XRPD pattern of sodium leucine dipeptide obtained in Example 1 is shown in FIG1 , and the data are shown in Table 1.

[0080] Table 1

[0081] The XRPD pattern of the potassium leucine dipeptide obtained in Example 2 is shown in FIG2 , and the data are shown in Table 2.

[0082] Table 2

[0083] The XRPD pattern of the leucine dipeptide calcium obtained in Example 3 is shown in FIG3 , and the data are shown in Table 3.

[0084] Table 3

[0085] The XRPD pattern of the magnesium leucine dipeptide obtained in Example 4 is shown in FIG4 , and the data are shown in Table 4.

[0086] Table 4

[0087] Infrared spectroscopy analysis

[0088] The infrared spectrum of the leucine dipeptide salt of each example was analyzed using a Shimadzu Fourier transform attenuated total reflection infrared spectrometer. Figure 5 is the infrared spectrum (IR) of leucine dipeptide sodium. It can be seen that the IR spectrum at 3314 cm -1 、2955cm -1 、2870cm -1 、1634cm -1 、1597cm-1 、1531cm -1 、1468cm -1 , 1400cm -1 、1366cm -1 、1163cm -1 、932cm -1 、868cm -1 、833cm -1 、766cm -1 、517cm -1 、469cm -1 Figure 6 is the infrared spectrum (IR) of potassium leucine dipeptide. It can be seen that the absorption peak at 3314 cm -1 、2955cm -1 、2868cm -1 、1639cm -1 、1589cm -1 、1522cm - 1 、1468cm -1 、1391cm -1 、1364cm -1 、1161cm -1 、1138cm -1 , 930cm - 1 、866cm -1 、756cm -1 、565cm -1 、517cm -1 、471cm -1 Figure 7 is the infrared spectrum (IR) of leucine dipeptide calcium. It can be seen that the absorption peak at 3339 cm -1 、2957cm -1 、2870cm -1 、1639cm -1 、1593cm -1 、1574cm -1 、1470cm -1 、cm -1 、1423cm -1 、1387cm -1 、1368cm -1 、1169cm -1 、868cm -1 、579cm - 1 Figure 8 is the infrared spectrum (IR) of leucine dipeptide magnesium. It can be seen that the absorption peak at 2957cm -1 、2870cm-1 、1636cm -1 、1526cm -1 、1470cm -1 、1420cm -1 、1387cm -1 、1368cm -1 、1169cm -1 There is a characteristic absorption peak.

[0089] Thermogravimetric analysis (TGA)

[0090] Figure 9 is a TGA chart of sodium leucine dipeptide, which shows a weight loss of 0.78% when heated from 26.0°C to 100.0°C, a weight loss of 0.58% when heated from 100.0°C to 210.0°C, and a weight loss of 3.37% when heated from 210.0°C to 300.0°C. Figure 10 is a TGA chart of potassium leucine dipeptide, which shows a weight loss of 0.66% when heated from 26.0°C to 100.0°C, a weight loss of 1.27% when heated from 100.0°C to 200.0°C, a weight loss of 5.03% when heated from 200.0°C to 250.0°C, and a weight loss of 3.22% when heated from 250.0°C to 290.0°C. Figure 11 is a TGA chart of leucine dipeptide calcium, which shows a 1.90% weight loss when heated from 26.5°C to 70.0°C, a 2.14% weight loss when heated from 70.0°C to 130.0°C, and a 2.36% weight loss when heated from 130.0°C to 230.0°C. Figure 12 is a TGA chart of leucine dipeptide magnesium, which shows a 0.67% weight loss when heated from 26.7°C to 100.0°C, and a 0.69% weight loss when heated from 100.0°C to 140.0°C.

[0091] Differential Scanning Calorimetry

[0092] Differential scanning calorimetry (DSC) was performed using a TA Q2000 module with a thermal analysis controller. Data were collected and analyzed using TA Instruments Thermal Solutions software. Approximately 1-5 mg of sample was accurately weighed into a custom aluminum crucible with a lid. Samples were analyzed from 40°C to approximately 300°C using a linear heating device at 10°C / min. During use, the DSC cell was purged with dry nitrogen.

[0093] Figure 13 is the DSC spectrum of sodium leucine dipeptide, including endothermic peaks at 193.99°C ± 3°C and 347.51°C ± 3°C. Figure 14 is the DSC spectrum of potassium leucine dipeptide, including endothermic peaks at 302.27°C ± 3°C and 342.94°C ± 3°C. Figure 15 is the DSC spectrum of calcium leucine dipeptide, including endothermic peaks at 77.68°C ± 3°C, 175.84°C ± 3°C, and 332.62°C ± 3°C. Figure 16 is the DSC spectrum of magnesium leucine dipeptide, including an endothermic peak at 296.33°C ± 3°C.

[0094] Elemental analysis

[0095] The leucine dipeptide salts of the examples were subjected to elemental analysis using an elemental analyzer, and the elemental analysis results of the salts were substantially consistent with those of the examples.

[0096] Quantitative NMR

[0097] The spectrometer records the leucine dipeptide salt of each example. 1 H NMR spectrum. 1 HNMR (400MHz, D2O): δ4.12-4.16(m,1H),3.95(t,1H),1.54-1.73(m,6H),0.82-0.92(m,12H).

[0098] Bare material placement-stability test

[0099] The leucine dipeptide salts of each example were placed under high temperature (60° C.) and light (4500 lux ± 500 lux) experimental conditions for 10 days to test their stability. The content results are shown in the following table:

[0100] The present invention can efficiently and stably produce a salt of leucine dipeptide; the leucine dipeptide salt of the present invention has good stability and better solubility; as well as better dissolution, performs excellently in an in vitro dissolution simulation experiment, and can have a wider application prospect in the fields of dietary supplements, food, etc.

[0101] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any person skilled in the art may make various changes, modifications, substitutions and variations to these embodiments without departing from the principles and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A physiologically acceptable salt of a leucine dipeptide, characterized in that The salt is selected from one or more of sodium salt, potassium salt, calcium salt and magnesium salt.

2. The salt according to claim 1, characterized in that The molar ratio of the leucine dipeptide to the metal is 1:1 to 2:

1.

3. The salt according to claim 1 or 2, characterized in that The salt is in crystalline form, amorphous form or a mixture thereof.

4. The salt according to any one of claims 1 to 3, characterized in that The X-ray powder diffraction pattern of the sodium leucine dipeptide includes peaks at diffraction angles (2θ) of 5.53°±0.20°, 6.23±0.20°, 13.30±0.20°, and 22.80±0.20°.

5. The salt according to claim 4, characterized in that The X-ray powder diffraction pattern of the sodium leucine dipeptide further includes one or more peaks at diffraction angles (2θ) of 7.27±0.20°, 17.83±0.20°, and 29.37±0.20°.

6. The salt according to claim 4 or 5, characterized in that The X-ray powder diffraction pattern of the sodium leucine dipeptide further includes one or more peaks at diffraction angles (2θ) of 10.05±0.20°, 17.29±0.20°, and 18.79±0.20°.

7. The salt according to any one of claims 1 to 6, characterized in that The X-ray powder diffraction pattern of the sodium leucine dipeptide is shown in FIG1 .

8. The salt according to any one of claims 1 to 3, characterized in that The infrared spectrum of the sodium leucine dipeptide has the following absorption bands, expressed as the reciprocal of the wavelength (cm -1 )(±2cm - 1 ): 3314, 2955, 2870, 1634, 1597, 1531, 1468, 1400, 1366, 1163, 932, 868, 833, 766, 517, 469.

9. The salt according to any one of claims 1 to 3, characterized in that The X-ray powder diffraction pattern of the potassium dipeptide leucine includes peaks at diffraction angles (2θ) of 5.24°±0.20°, 9.35°±0.20°, 18.58°±0.20°, and 22.05°±0.20°.

10. The salt according to claim 9, characterized in that The X-ray powder diffraction pattern of the potassium dipeptide leucine further includes one or more peaks at diffraction angles (2θ) of 6.53°±0.20°, 10.77°±0.20°, and 26.96°±0.20°.

11. The salt according to claim 9 or 10, characterized in that The X-ray powder diffraction pattern of the potassium dipeptide leucine further includes one or more peaks at diffraction angles (2θ) of 7.38°±0.20°, 16.10°±0.20°, and 19.34°±0.20°.

12. The salt according to any one of claims 1 to 3, 9 to 11, characterized in that The X-ray powder diffraction pattern of the leucine dipeptide potassium is shown in FIG2 .

13. The salt according to any one of claims 1 to 3, characterized in that The infrared spectrum of the potassium leucine dipeptide has the following absorption bands, expressed as the reciprocal of the wavelength (cm -1 )(±2cm -1 ): 3314, 2955, 2868, 1639, 1589, 1522, 1468, 1391, 1364, 1161, 1138, 930, 866, 756, 565, 517, 471.

14. The salt according to any one of claims 1 to 3, characterized in that The X-ray powder diffraction pattern of the leucine dipeptide calcium includes peaks at diffraction angles (2θ) of 4.53°±0.20°, 6.11°±0.20°, 13.47°±0.20°, and 17.88°±0.20°.

15. The salt according to claim 14, characterized in that The X-ray powder diffraction pattern of the leucine dipeptide calcium further includes one or more peaks located at diffraction angles (2θ) of 5.32°±0.20°, 9.01°±0.20°, and 19.44°±0.20°.

16. The salt according to claim 14 or 15, characterized in that The X-ray powder diffraction pattern of the leucine dipeptide calcium further includes one or more peaks located at diffraction angles (2θ) of 7.07°±0.20°, 14.44°±0.20°, and 24.58°±0.20°.

17. The salt according to any one of claims 1 to 3, 14 to 16, characterized in that The X-ray powder diffraction pattern of the leucine dipeptide calcium is shown in FIG3 .

18. The salt according to any one of claims 1 to 3, characterized in that The infrared spectrum of the calcium leucine dipeptide has the following absorption bands, expressed as the reciprocal of the wavelength (cm -1 )(±2cm -1 ): 3339, 2957, 2870, 1639, 1593, 1574, 1470, cm -1 、1423、1387、1368、1169、868、579。 19. The salt according to any one of claims 1 to 3, characterized in that The X-ray powder diffraction pattern of the leucine dipeptide magnesium includes peaks at diffraction angles (2θ) of 6.23°±0.20° and 18.25°±0.20°.

20. The salt according to any one of claims 1 to 3 and 19, characterized in that The X-ray powder diffraction pattern of the leucine dipeptide magnesium is shown in FIG4 .

21. The salt according to any one of claims 1 to 3, characterized in that The infrared spectrum of the leucine dipeptide magnesium has the following absorption bands, expressed as the reciprocal of the wavelength (cm -1 )(±2cm -1 ): 2957, 2870, 1636, 1526, 1470, 1420, 1387, 1368, 1169.

22. A method for preparing the salt according to any one of claims 1 to 21, characterized in that: The method comprises: reacting leucine dipeptide with an alkaline metal compound; concentrating, adding a solvent, heating, dissolving; cooling to precipitate a solid, and drying to obtain the salt.

23. The preparation method according to claim 22, characterized in that The alkaline metal compound is selected from one or more of the following: oxides, peroxides, hydrides, hydroxides, and organic metal bases of sodium, potassium, calcium, and magnesium.

24. The preparation method according to claim 22 or 23, characterized in that: The solvent is selected from one or more of the following: methanol, ethanol, propanol, isopropanol, butanol, acetonitrile, acetone, methyl ethyl ketone, ethyl acetate, butyl acetate, isopropanol acetate, and water.

25. The preparation method according to any one of claims 22 to 24, characterized in that Raise the temperature to 40-80℃.

26. The salt according to any one of claims 1 to 21, characterized in that The salt is used to prepare food, beverages, supplements, and nutritional products.

27. A composition, characterized in that The composition comprises the salt of any one of claims 1 to 21, and a leucine dipeptide.

28. The composition according to claim 27, characterized in that The proportion of the physiologically acceptable salt of the leucine dipeptide is greater than 55%.

29. The composition according to claim 27 or 28, characterized in that The composition also includes a physiologically acceptable carrier.

30. The composition according to any one of claims 27 to 29, characterized in that The composition is used for preparing food, beverage, supplement and nutrition product.

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