A novel dipeptide sweetener and its synthesis method

Abstract

The application discloses a novel dipeptide sweetener and a synthesis method thereof. The sweetener is N-〔N-(2,3,4,5-tetrahydroxy) methyl-L-alpha-aspartyl〕-L-phenylalanine-1-methyl ester, which is synthesized from aspartame and L-arabinose. The sweetener has a pure taste and is close to the taste of sucrose, the sweetness multiple is 800-1000 times that of sucrose, the synthesis process is simple, the operation is convenient, the cost is relatively low, the green development is met, industrialization is easy to realize, and the sweetener has good use value and economic value in the field of food technology.

Description

Technical Field

[0001] This invention belongs to the field of food additive technology, specifically relating to a novel dipeptide sweetener and its synthesis method. Background Technology

[0002] Sweeteners, as compounds that provide sweetness, are widely used in various products such as food, beverages, and pharmaceuticals to enhance their taste and flavor. Aspartame, a common sweetener, is a dipeptide composed of aspartic acid and phenylalanine, and its sweetness is 180 to 220 times that of sucrose. L-arabinose, a naturally occurring sugar, has a sweetness approximately 0.5% that of sucrose and is often used as a food additive, possessing good sweetness and anti-caries effects. Developing novel sweeteners that can replace sucrose and offer advantages such as high sweetness, safety, and low cost is one of the research goals in the field of food additives. Summary of the Invention

[0003] To address the aforementioned shortcomings of existing technologies, the present invention aims to provide a novel dipeptide sweetener and its synthesis method that is simple to operate, safe, and relatively cost-effective. This novel dipeptide sweetener is N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester, a reaction product of aspartame and L-arabinose. Its sweetness is 800-1000 times that of sucrose, significantly increasing sweetness and providing a taste close to sucrose. It avoids the lingering sweetness and artificial sweetness often associated with high-intensity sweeteners, and can replace sucrose or other sweeteners for widespread use in the food, beverage, and pharmaceutical industries.

[0004] The first objective of this invention is to provide a dipeptide sweetener, namely N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester, with the structural formula shown in Formula I:

[0005]

[0006] A second object of the present invention is to provide a method for synthesizing N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester, comprising the following steps:

[0007] S1. Add ethanol, dehydrating agent, aspartame and L-arabinose to the reaction vessel in sequence and heat until fully dissolved;

[0008] S2. Add palladium on carbon catalyst to the solution and mix thoroughly. Replace the air in the reaction system with a protective gas, then introduce hydrogen gas and pressurize to carry out the hydrogenation reduction reaction.

[0009] S3. After the reaction, the reaction solution is filtered under reduced pressure, the filtrate is collected, concentrated under reduced pressure, and the concentrate is recrystallized and purified to obtain N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester.

[0010] The corresponding synthesis reaction formula is as follows:

[0011]

[0012] In this context, Me represents methyl (methyl group).

[0013] Preferably, in step S1, the molar ratio of L-arabinose to aspartame is 0.5-4:1, the molar ratio of dehydrating agent to aspartame is 1-10:1, the mass ratio of ethanol to aspartame is 5-20:1, and the mass ratio of palladium catalyst on carbon to aspartame is 0.01-0.1:1.

[0014] More preferably, in step S1, the molar ratio of L-arabinose to aspartame is 1.8-4:1, the molar ratio of dehydrating agent to aspartame is 1.9-5.9:1, the mass ratio of ethanol to aspartame is 7.5-14.5:1, and the mass ratio of palladium catalyst on carbon to aspartame is 0.035:1.

[0015] The dehydrating agent is any one or a combination of two or more of the following: anhydrous ferric chloride, anhydrous ferrous chloride, anhydrous magnesium chloride, anhydrous calcium chloride, anhydrous lithium chloride, anhydrous potassium chloride, anhydrous sodium chloride, anhydrous sodium bicarbonate, anhydrous potassium bicarbonate, anhydrous lithium bicarbonate, anhydrous potassium acetate, anhydrous sodium acetate, anhydrous lithium acetate, anhydrous calcium acetate, anhydrous magnesium acetate, anhydrous ferrous acetate, anhydrous sodium sulfate, anhydrous potassium sulfate, anhydrous magnesium sulfate, anhydrous lithium sulfate, anhydrous sodium dihydrogen phosphate, anhydrous disodium hydrogen phosphate, and anhydrous potassium hydrogen phosphate.

[0016] The amount of dehydrating agent used is calculated based on the water content of the reaction system and the dehydrating ability of the dehydrating agent. For example, if the total water content in the solvent and reagents is A, and the dehydrating ability of the dehydrating agent is B, then B must always be greater than A. The purpose of adding a dehydrating agent to the reaction is mainly to bind the water in the reaction system, including water introduced by the reactants and water generated in the reaction, thereby promoting the condensation reaction to proceed fully. Therefore, the amount of dehydrating agent added to the reaction system is usually more than the total amount of water in the reaction system.

[0017] The palladium-on-carbon catalyst has a water content of 40%-60% and a palladium content (excluding water) of 5%-10% by mass. Before use, it is washed with methanol or ethanol to remove more than 90% of the water before being used in the catalytic reaction.

[0018] Preferably, the palladium-on-carbon catalyst has a water content of 50% and a palladium content (excluding water) of 10% by mass. Before use, it is washed with ethanol to remove more than 90% of the water before being used in the catalytic reaction. The amount of palladium-on-carbon catalyst used in the reaction is based on the mass of the catalyst before water removal (i.e., with a water content of 50%).

[0019] Preferably, the heating temperature in step S1 is 30℃-45℃.

[0020] Preferably, in step S2, adding the palladium-on-carbon catalyst to the solution and mixing thoroughly allows the mixing reaction to proceed for 0.5-2 hours. The purpose is to ensure thorough mixing of the palladium-on-carbon catalyst with the solution, which facilitates subsequent catalytic reactions. The protective gas is nitrogen or an inert gas.

[0021] Preferably, in step S2, the hydrogenation reduction reaction involves introducing hydrogen gas and controlling the hydrogen pressure at 8.5–10 atm, the reaction temperature at 30°C–50°C, and the reaction time at 10–16 hours. Lower reaction pressures result in longer reaction times; higher pressures lead to increased byproducts. The hydrogenation reduction reaction time is determined based on HPLC detection results, taking into account both economic cost and the yield of the synthesized product.

[0022] Preferably, the recrystallization purification of the concentrate in step S3 involves adding a 50% (v / v) aqueous ethanol solution to the concentrate to dissolve and crystallize it.

[0023] Preferably, step S3 involves: adding an appropriate amount of water to the reaction solution after the reaction, filtering under reduced pressure, collecting the filtrate, recovering the palladium catalyst on carbon and washing with ethanol, collecting the washing liquid and combining the filtrates, concentrating under reduced pressure, and recrystallizing and purifying the concentrate to obtain N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester. In other words, step S3 may also include a step of recovering the palladium catalyst on carbon, thereby achieving the recycling and utilization of the palladium catalyst on carbon.

[0024] A third object of the present invention is to provide the use of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester in the preparation of products containing sweeteners.

[0025] Preferably, the product containing sweetener is a food, beverage, or pharmaceutical.

[0026] The present invention has the following beneficial effects:

[0027] This invention utilizes aspartame and L-arabinose in a synthetic reaction to produce N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester. This product has a pure taste, close to that of sucrose, and a sweetness multiple 800-1000 times that of sucrose, significantly different in taste from high-intensity sweeteners such as Advantest, neotame, and stevia. The synthesis process of this invention is simple, convenient, and relatively inexpensive, aligning with green development principles and easily industrialized, demonstrating significant practical and economic value in the food processing field. Attached Figure Description

[0028] Figure 1 This is the chromatogram of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester.

[0029] Figure 2 This is the mass spectrum of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester.

[0030] Figure 3 This is a radar chart showing the sensory flavor characteristics of sweeteners. Detailed Implementation

[0031] The following embodiments are further illustrations of the present invention, but not limitations thereof.

[0032] The following reagents were used: Ethanol was purchased from Jinan Century Tongda Chemical Co., Ltd., anhydrous ethanol with a purity of 99.9%; anhydrous sodium chloride was purchased from Aipu Science, model: B1017, purity: ≥99.5%; aspartame was purchased from Jiangsu Hanguang Sweetener Co., Ltd., model: Hanguang aspartame, purity: ≥99.5%; L-arabinose was purchased from Jiangsu Dongju Biotechnology Co., Ltd., model: food grade, purity: 99%; palladium on carbon catalyst was purchased from Sigma-Aldrich (China), model: palladium on carbon (10%).

[0033] The instruments used were: a 400MHz nuclear magnetic resonance spectrometer manufactured by Bruker GmbH, Switzerland, model: AVANCE NEO400MHz NMR SPECTROMETER NANO; an Agilent liquid chromatography / quadrupole-time-of-flight mass spectrometer (LC / Q-TOF); and an Agilent HPLC 1260 Infinity I.

[0034] Example 1

[0035] A method for synthesizing a novel sweetener includes the following steps.

[0036] S1. Add 180mL of ethanol, 11.7g of anhydrous sodium chloride, 10g of aspartame and 20g of L-arabinose to the reaction vessel, heat to 45℃ and dissolve completely;

[0037] S2. Take 0.35g of palladium on carbon catalyst (the water content of palladium on carbon catalyst is 50%, and the mass ratio of palladium excluding water is 10%), wash it twice with 20mL of ethanol to remove more than 90% of the water, and then add it to the solution prepared in step S1. Mix and react for 2 hours before proceeding to step S3.

[0038] S3. Replace the air in the reactor with nitrogen, and then replace the nitrogen in the reactor with hydrogen. Control the hydrogen pressure to 10 atm and the reaction temperature to 50°C to carry out the hydrogenation reduction reaction. After 16 hours of reaction, the reaction solution enters step S4.

[0039] S4. After the reaction is complete, the reaction pressure is released and replaced with nitrogen. 10 mL of water is added to the reaction solution, the solution is filtered under reduced pressure, the filtrate is collected, the palladium on carbon catalyst is recovered and washed with ethanol, the washing liquid is collected and the filtrates are combined and concentrated under reduced pressure to a slurry to obtain the crude product (i.e., the concentrate). Then, a 50% (v / v) ethanol aqueous solution is added to the concentrate to dissolve and crystallize, and a new sweetener is obtained.

[0040] NMR and mass spectrometry analysis confirmed that the sweetener in the product was N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester. The chromatogram of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester is shown below. Figure 1 As shown. HPLC analysis revealed that the purity of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester in the crude product reached 78.09%; 11.5 g of the new sweetener was obtained, of which the purity of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester was 85.4%, and the yield (actual yield divided by theoretical yield) was 82.1%.

[0041] The N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester prepared in Example 1 has the following NMR spectral characteristics: 13C10 NMR (100MHz, CD3Cl): 175.1, 173.2, 171.7, 136.6, 128.6, 128.6, 127.7, 127.7, 125.9, 72.8, 72.1, 72.0, 64.4, 61.2, 56.7, 51.9, 49.9, 40.6, 36.8. The mass spectrum of the prepared N-[N-(2,3,4,5-tetrahydroxymethyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester is shown below. Figure 2 As shown, the mass spectrometry analysis data are as follows: MS (ESI, m / z) 427.17 (MH). + ); The theoretical calculation data for high-resolution electrospray ionization mass spectrometry are [C 19 H 28 N2O9]-(MH + The actual measured value was 427.1737, not 427.1717.

[0042] Example 2

[0043] A method for synthesizing a novel sweetener includes the following steps:

[0044] S1. Add 140mL of ethanol, 7.8g of anhydrous sodium chloride, 10g of aspartame and 20g of L-arabinose to the reaction vessel, heat to 35℃ and dissolve completely;

[0045] S2. Take 0.35g of palladium on carbon catalyst (the water content of palladium on carbon catalyst is 50%, and the mass ratio of palladium excluding water is 10%), wash it twice with 20mL of ethanol to remove more than 90% of the water, and then add it to the solution prepared in step S1. After reacting for 1h, proceed to step S3.

[0046] S3. Replace the air in the reactor with nitrogen, and then replace the nitrogen in the reactor with hydrogen. Control the hydrogen pressure to 8.5 atm, mix and react at 40°C, and carry out the hydrogenation reduction reaction. After reacting for 13 hours, the reaction solution enters step S4.

[0047] S4. After the reaction is complete, the reaction pressure is released and replaced with nitrogen. 10 mL of water is added to the reaction solution, the solution is filtered under reduced pressure, the filtrate is collected, the palladium on carbon catalyst is recovered and washed with ethanol, the washing liquid is collected and the filtrates are combined and concentrated under reduced pressure to a slurry to obtain the crude product (i.e., the concentrate). Then, a 50% (v / v) ethanol aqueous solution is added to the concentrate to dissolve and crystallize, and a new sweetener is obtained.

[0048] HPLC analysis showed that the purity of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester in the crude product reached 77.91%. 10.8 g of the new sweetener was obtained, with the purity of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester at 83.1%, and the yield at 77.1%.

[0049] Example 3

[0050] A method for synthesizing a novel sweetener includes the following steps:

[0051] S1. Add 100mL of ethanol, 3.9g of anhydrous sodium chloride, 10g of aspartame and 10g of L-arabinose to the reaction vessel, heat to 30℃ and dissolve completely;

[0052] S2. Take 0.35g of palladium on carbon catalyst (the water content of palladium on carbon catalyst is 50%, and the mass ratio of palladium excluding water is 10%), wash it twice with 20mL of ethanol to remove more than 90% of the water, and then add it to the solution prepared in step S1. Mix and react for 0.5h before proceeding to step S3.

[0053] S3. Replace the air in the reactor with nitrogen, and then replace the nitrogen in the reactor with hydrogen. Control the hydrogen pressure to 8.5 atm and the reaction temperature to 30°C to carry out the hydrogenation reduction reaction. After reacting for 10 hours, the reaction solution enters step S4.

[0054] S4. After the reaction is complete, the reaction pressure is released and replaced with nitrogen. 10 mL of water is added to the reaction solution, the solution is filtered under reduced pressure, the filtrate is collected, the palladium on carbon catalyst is recovered and washed with ethanol, the washing liquid is collected and the filtrates are combined and concentrated under reduced pressure to a slurry to obtain the crude product (i.e., the concentrate). Then, a 50% (v / v) ethanol aqueous solution is added to the concentrate to dissolve and crystallize, and a new sweetener is obtained.

[0055] HPLC analysis showed that the purity of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester in the crude product reached 66.35%; 6.995 g of the new sweetener was obtained, of which the purity of N-[N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartic acid]-L-phenylalanine-1-methyl ester was 72.6%, and the yield was 67.8%.

[0056] Example 4: Evaluation of the new sweetener

[0057] I. Sweetness Evaluation

[0058] The relative sweetness of the new sweetener prepared in Example 1 was determined by scaling test.

[0059] Ten sucrose solutions of varying concentrations (1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 6.0%, 7.0%, 8.0%, 9.0%, and 10% (w / w)) were prepared as references. Since the new sweetener prepared in Example 1 was too sweet to be properly evaluated, it was first diluted 1000 times with purified water to obtain a 1000-fold dilution. This 1000-fold dilution was then used as a stock solution to prepare 2% and 5% 1000-fold dilutions of the new sweetener (i.e., the mass percentage of the new sweetener component in the 2% 1000-fold dilution was 2% * 1‰, and the mass percentage of the new sweetener component in the 5% 1000-fold dilution was 5% * 1‰) as test samples.

[0060] All experimental sample solutions were prepared using purified water and allowed to stand at room temperature (22±1℃) beforehand. Each solution was prepared based on a mass ratio (w / w). The sample solutions were placed in 50mL test cups.

[0061] Ten experienced perfumers with more than five years of experience were invited to evaluate the sweetener. Each tester was provided with ten reference sucrose solutions of varying concentrations and two test samples of the new sweetener at different concentrations. The sample that best matched the sweetness of sucrose was selected. The test results are shown in Table 1.

[0062] Table 1. Sweetness Test Results

[0063]

[0064]

[0065] Analysis of the test results shows that the sweetness multiple of the new sweetener prepared in Example 1 is 800 to 1000 times that of sucrose, and as the concentration of the new sweetener increases, its sweetness multiple relative to sucrose tends to decrease.

[0066] II. Sweetness Evaluation

[0067] Ten experienced perfumers with over five years of experience were invited to evaluate the sensory flavor characteristics of different sweetener products. Six flavor characteristic indicators were identified through screening: sugar sweetness, artificial sweetness, off-flavor, metallic taste, mouthfeel, and aftertaste, using sucrose flavor characteristics as a reference. Preliminary testing, using 5% sucrose sweetness as a standard, yielded a series of samples with equal sweetness levels of steviol glycosides, sucralose, aspartame, neotame, and the new sweetener prepared in Example 1. The concentrations of each sweetener (Table 2) are explained below:

[0068] Sample No. 1 was prepared by dissolving sucrose in a 5% (w / w) aqueous solution and then used for tasting and evaluation.

[0069] Sample No. 2 was prepared by diluting steviol glycosides 100 times to form a steviol glycoside stock solution (i.e., preparing a 1% steviol glycoside aqueous solution as a steviol glycoside stock solution). Then, 10 mL of the steviol glycoside stock solution was taken and water was added to make up to 1000 mL for dilution and mixing (i.e., preparing a 1% steviol glycoside stock solution). It was then used for tasting and evaluation.

[0070] Sample No. 3 was prepared by diluting sucralose 100 times to make a sucralose stock solution (i.e., preparing a 1% sucralose aqueous solution as the sucralose stock solution). Then, 8 mL of the sucralose stock solution was taken and water was added to make up to 1000 mL for dilution and mixing (i.e., preparing a 0.8% concentration of sucralose stock solution), and then used for tasting and evaluation.

[0071] Sample No. 4 was prepared by diluting aspartame 100 times to make aspartame stock solution (i.e., preparing aspartame into a 1% aspartame aqueous solution as aspartame stock solution). Then, 25 mL of aspartame stock solution was taken and water was added to make up to 1000 mL for dilution and mixing (i.e., preparing aspartame stock solution with a concentration of 2.5%). Then it was used for tasting evaluation.

[0072] Sample No. 5 was prepared by diluting neotame 1000 times to make neotame stock solution (i.e., preparing neotame into a 0.1% mass fraction aqueous solution as neotame stock solution). Then, 6 mL of neotame stock solution was taken, and water was added to make up to 1000 mL for dilution and mixing (i.e., preparing a 0.6% concentration of neotame stock solution), and then used for tasting evaluation.

[0073] Sample No. 6 was prepared by diluting the new sweetener 1000 times to form the new sweetener stock solution (i.e., preparing the new sweetener into a 0.1% (w / w) aqueous solution as the new sweetener stock solution). Then, 40 mL of the new sweetener stock solution was taken, and water was added to make up to 1000 mL for dilution and mixing (i.e., preparing a 4% concentration of the new sweetener stock solution), and then used for tasting evaluation.

[0074] All experimental sample solutions were prepared using purified water and allowed to stand at room temperature (22±1℃) beforehand. Each solution was prepared based on a mass ratio (w / w). The sample solutions were placed in 50mL test cups and evaluated by the evaluators.

[0075] Using sucrose as the standard, the test results are shown in Table 2. The numerical results in Table 2 are scored from 1 to 5, with higher scores indicating more significant indicators.

[0076] Table 2. Results of the sweetness test

[0077]

[0078] A radar chart was plotted based on the intensity of the six sensory characteristic indicators corresponding to each sample in Table 2, thereby determining the flavor characteristics of each sweetener. The radar chart results are shown below. Figure 3 As shown.

[0079] Analysis of the test results shows that the new sweetener prepared in Example 1 has a sweetness and flavor index close to that of sucrose, and has certain advantages over steviol glycosides, sucralose, aspartame, and neotame. This experiment verifies the taste and flavor characteristics of the new sweetener, and it can be considered for future widespread application in the food, beverage, and pharmaceutical industries as a replacement for sucrose or other sweeteners.

Claims

1. A dipeptide sweetener characterized by, N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester, the structural formula is shown as formula I: Formula I.

2. A method for synthesizing N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester, comprising the following steps: S1, ethanol, dehydrating agent, aspartame and L-arabinose are sequentially added into a reaction kettle, heated to 30-45 DEG C to fully dissolve; the mass ratio of L-arabinose to aspartame is 1.8-4:1, the mass ratio of dehydrating agent to aspartame is 1.9-5.9:1, the mass ratio of ethanol to aspartame is 7.5-14.5:1, and the mass ratio of palladium-carbon catalyst to aspartame is 0.035:1; S2, palladium-carbon catalyst is added into the dissolved solution and fully mixed for 0.5-2 h, the air in the reaction system is replaced by protective gas, hydrogen is introduced, the hydrogen pressure is controlled at 8.5-10 atm, the reaction temperature is 30-50 DEG C, and the reaction is carried out for 10-16 h; S3, the reaction liquid after reaction is filtered under reduced pressure, the filtrate is collected, concentrated under reduced pressure, 50% ethanol aqueous solution is added into the concentrated liquid, the crystallization is dissolved, and N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester is obtained.

3. The method of synthesis of claim 2, wherein, The dehydrating agent is any one or a combination of two or more of anhydrous ferric chloride, anhydrous ferrous chloride, anhydrous magnesium chloride, anhydrous calcium chloride, anhydrous lithium chloride, anhydrous potassium chloride, anhydrous sodium chloride, anhydrous sodium bicarbonate, anhydrous potassium bicarbonate, anhydrous lithium bicarbonate, anhydrous potassium acetate, anhydrous sodium acetate, anhydrous lithium acetate, anhydrous calcium acetate, anhydrous magnesium acetate, anhydrous ferrous acetate, anhydrous sodium sulfate, anhydrous potassium sulfate, anhydrous magnesium sulfate, anhydrous lithium sulfate, anhydrous sodium dihydrogen phosphate, anhydrous disodium hydrogen phosphate, and anhydrous potassium hydrogen phosphate; the palladium-carbon catalyst has a water content of 50%, a mass ratio of palladium to other components is 10%, and more than 90% of water is removed by washing with ethanol before use.

4. The method of synthesis of claim 2, wherein, The protective gas is nitrogen or inert gas.

5. The method of synthesis of claim 2, wherein, S3, an appropriate amount of water is added into the reaction liquid after reaction, filtered under reduced pressure, the filtrate is collected, the palladium-carbon catalyst is recovered and washed with ethanol, the washing liquid and the filtrate are collected, concentrated under reduced pressure, 50% ethanol aqueous solution is added into the concentrated liquid, the crystallization is dissolved, and N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester is obtained.

6. Use of N-〔N-(2,3,4,5-tetrahydroxy)methyl-L-α-aspartyl〕-L-phenylalanine-1-methyl ester in preparing a product containing a sweetener.

7. Use according to claim 6, characterized in that, The product containing a sweetener is food, beverage or medicine.

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