Preparation method of magnesium threonate

Abstract

The invention relates to a preparation method of magnesium threonate, which comprises the following steps: taking magnesium hydroxide, vitamin C and hydrogen peroxide which are cheap and easy to obtain as raw materials, reacting in ethanol to obtain a target product, and recrystallizing through an ethanol and water system to obtain pure magnesium threonate.

Description

Technical Field

[0001] The invention relates to the technical field of organic synthesis, in particular to a method for preparing magnesium threonate. Background Art

[0002] Magnesium L-threonate (abbreviated as Magtein, pronounced "Megtai") is a chemical substance with the chemical formula:

[0003] Professor Liu Guosong, together with teams from Tsinghua University and MIT, discovered that magnesium threonate has the effects and functions of enhancing memory, improving sleep quality, relieving anxiety, improving immunity, and promoting bone health.

[0004] The existing preparation methods of magnesium threonate are as follows: (1) Acid hydrolysis: Corn starch or beet starch is hydrolyzed under the action of acid to produce glucose, which is then fermented to produce L-threose. Finally, L-threose is reacted with magnesium hydroxide to produce magnesium L-threonate.

[0005] (2) Direct synthesis method: Glucose is directly reacted with magnesium hydroxide to produce L-magnesium threonate.

[0006] (3) Enzymatic hydrolysis: Use enzymes to hydrolyze corn starch or beet starch into glucose, which is then fermented to produce L-threose. Finally, L-threose is reacted with magnesium hydroxide to produce magnesium L-threonate.

[0007] Among the above three methods, acid hydrolysis and direct synthesis require the use of a large amount of acid and alkali, which have a certain impact on the environment, while enzymatic hydrolysis can reduce the use of acid and alkali to a certain extent and has less impact on the environment, but the process is more complicated. Therefore, a new preparation method is needed to solve the above problems. Summary of the invention

[0008] In view of the above-mentioned deficiencies of the prior art, the present invention provides a method for preparing magnesium threonate, which uses cheap and readily available magnesium hydroxide, vitamin C, and hydrogen peroxide as raw materials, reacts in ethanol to obtain a target product, and then recrystallizes through an ethanol and water system to obtain pure magnesium threonate.

[0009] The technical solution adopted by the present invention is: A method for preparing magnesium threonate comprises the following steps: 1) Add a certain amount of water and vitamin C to the container, control the temperature at 0-15°C, add magnesium hydroxide in batches, and react for 1-5 hours; 2) After the reaction in step 1, the solution was cooled to -10~5℃, and a certain amount of hydrogen peroxide was slowly added. After the addition was completed, the temperature was raised to 25℃ and reacted for 2h; 3) After the reaction is completed, the temperature is raised to 85°C and stirred for 2 hours, the hydrogen peroxide is evaporated to remove, the mixture is cooled to room temperature, the pH is adjusted to 5.5-6.5, and then the solvent is removed by rotary evaporation to obtain crude magnesium threonate; 4) Add a certain amount of water and heat to dissolve, then add a certain amount of ethanol dropwise until a white solid precipitates and then disappears immediately, cool naturally to room temperature, and stir continuously to crystallize for 5 hours; filter and rinse the solid phase with ethanol, and dry to obtain magnesium threonate.

[0010] Furthermore, the volume of water in step 1 is 4-10 times the mass of vitamin C.

[0011] Preferably, in step 1, the temperature is controlled at 10° C. and the reaction is carried out for 2 hours.

[0012] Preferably, the temperature is lowered to 0°C in step 2.

[0013] Preferably, the pH in step 3 is 6.

[0014] Beneficial effects of the present invention: Compared with the prior art, the preparation method of the present invention effectively reduces the synthesis cost, avoids the use of dangerous and toxic reagents, effectively reduces the generation of industrial waste, and has simple process, convenient operation, cheap and easily available raw materials, high yield, and is conducive to large-scale industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the nuclear magnetic resonance test result of the magnesium threonate prepared by the present invention; Figure 2 The following are the TGA and DSC curves of the magnesium threonate prepared in the present invention. DETAILED DESCRIPTION

[0016] The present invention is further described below in conjunction with specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0017] In order to make the technical means, creative features, purpose and efficacy of the present invention easy to understand, the present invention is further explained in conjunction with specific examples below. In the following examples, unless otherwise specified, the operating methods used are conventional operating methods, the equipment used are conventional equipment, and the raw materials used are commercially available. The present invention is further described below in conjunction with examples.

[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows.

[0019] Example 1 Step 1: Add 4L of water and vitamin C (1244.17g, 1.940mol) into a 50L reactor and control the temperature at 10°C. Add magnesium hydroxide (74.5g, 1.940mol) into the reactor in batches and react for 2h. The solution in the reactor changes from clear to milky white turbid.

[0020] Step 2: Preparation of magnesium threonate The 50L reactor was cooled to 0°C, and hydrogen peroxide (606.29 g, 4.65 mol) was added dropwise under constant stirring. The temperature was then raised to 25°C and stirred for reaction for 2 h. The reaction raw material vitamin C was observed by TLC plate. The reaction was completed when the fluorescent spot disappeared.

[0021] After the reaction was completed, the solution in the reactor was heated to 85° C., stirred in the open air for about 2 h, and then cooled to 25° C. The solvent was removed by rotary evaporation to obtain 1136.22 g of pale yellow crude magnesium threonate.

[0022] 1136.22 g of the crude product was heated to 80°C with 5.5 L of water to dissolve, and 5.5 L of ethanol was slowly added until a white solid precipitated and dissolved. The product was naturally cooled to room temperature, stirred for crystallization at room temperature for 5 h, and then filtered and rinsed with 3.3 L of ethanol to obtain a white solid, which is pure magnesium threonate. The solid was dried at 65°C to obtain 1145.32 g, with a yield of 82.47%.

[0023] Example 2 Step 1: Add 4L of water and vitamin C (1244.17g, 1.940mol) into a 50L reactor and control the temperature at 10°C. Add magnesium hydroxide (74.5g, 1.940mol) into the reactor in batches and react for 2h. The solution in the reactor changes from clear to milky white turbid.

[0024] Step 2: Preparation of magnesium threonate The 100L reactor was cooled to 0°C, and hydrogen peroxide (1212.3 g, 9.3 mol) was added dropwise under constant stirring. The temperature was then raised to 25°C and stirred for reaction for 2 h. The reaction raw material vitamin C was observed by TLC plate. The reaction was completed when the fluorescent spot disappeared.

[0025] After the reaction was completed, the solution in the reactor was heated to 85° C. and stirred in the open air for about 2 h. The temperature was then lowered to 25° C. The solvent was removed by rotary evaporation to obtain 2311.22 g of pale yellow crude magnesium threonate.

[0026] 2311.22 g of the above crude product was heated to 80°C with 11 L of water to dissolve, and 11 L of ethanol was slowly added until a white solid precipitated and dissolved. The mixture was naturally cooled to room temperature, stirred for crystallization at room temperature for 5 h, and then filtered and rinsed with 6.6 L of ethanol to obtain a white solid, which is pure magnesium threonate. The solid was dried at 65°C to obtain 2393.32 g, with a yield of 81.88%.

[0027] By drying magnesium L-threonate at 155°C to constant weight and TGA / DSC thermodynamic analysis, it was found that this product contains 0.5 crystal water.

[0028] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown here.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing magnesium threonate, characterized in that: The following steps are involved: 1) Add a certain amount of water and vitamin C to the container, control the temperature at 0-15°C, add magnesium hydroxide in batches, and react for 1-5 hours; 2) After the reaction in step 1, the solution was cooled to -10~5℃, and a certain amount of hydrogen peroxide was slowly added. After the addition was completed, the temperature was raised to 25℃ and reacted for 2h; 3) After the reaction is completed, the temperature is raised to 85°C and stirred for 2 hours, the hydrogen peroxide is evaporated to remove, the mixture is cooled to room temperature, the pH is adjusted to 5.5-6.5, and then the solvent is removed by rotary evaporation to obtain crude magnesium threonate; 4) Add a certain amount of water and heat to dissolve, then add a certain amount of ethanol dropwise until a white solid precipitates and then disappears immediately, cool naturally to room temperature, and stir continuously to crystallize for 5 hours; filter and rinse the solid phase with ethanol, and dry to obtain magnesium threonate.

2. The method for preparing magnesium threonate according to claim 1, characterized in that: The volume of water in step 1 is 4-10 times the mass of vitamin C.

3. The method for preparing magnesium threonate according to claim 1, characterized in that: In step 1, the temperature is controlled at 10° C. and the reaction is performed for 2 hours.

4. The method for preparing magnesium threonate according to claim 1, characterized in that: In the step 2, the temperature is lowered to 0°C.

5. The method for preparing magnesium threonate according to claim 1, characterized in that: In step 3, the pH is 6.

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