阅读说明：本技术 一种新型氨基酸自组装超分子聚合物及其制备方法和应用 (Novel amino acid self-assembled supramolecular polymer and preparation method and application thereof ) 是由 张健 于 2018-08-06 设计创作，主要内容包括：本发明公开了一种新型氨基酸自组装超分子聚合物的制备和应用,该自组装超分子化合物为N-月桂酰-L-丙氨酰-L-丙氨酸或其盐,其盐包括N-月桂酰-L-丙氨酰-L-丙氨酸钠和N-月桂酰-L-丙氨酰-L-丙氨酸钾。本发明公开的聚合物具有更有效的抑菌、去农药等效果,可广泛应用于日化、农业和医药行业。本发明还公开了三种制备该化合物的方法。所述的方法得到的产物产率高,适于工业化生产。(The invention discloses a preparation method and application of a novel amino acid self-assembly supermolecule polymer, wherein the self-assembly supermolecule compound is N-lauroyl-L-alanyl-L-alanine or salt thereof, and the salt comprises N-lauroyl-L-alanyl-L-alanine sodium and N-lauroyl-L-alanyl-L-alanine potassium. The polymer disclosed by the invention has more effective effects of bacteriostasis, pesticide removal and the like, and can be widely applied to the industries of daily chemicals, agriculture and medicines. The invention also discloses three methods for preparing the compound. The method has high product yield and is suitable for industrial production.)

1. A novel monomer of amino acid self-assembly supermolecular polymer is a compound with the following structure:

wherein R is selected from H, Na or K.

2. A novel amino acid self-assembled supramolecular polymer has the following structural characteristics:

3. a novel amino acid self-assembly supermolecule polymer is characterized in that N-lauroyl-L-alanyl-L-alanine is used as a basic unit and is self-assembled into the supermolecule polymer through a hydrogen bond, and the weight average molecular weight data is 5000-500 ten thousand.

4. A novel amino acid self-assembling supramolecular polymer as claimed in claim 3, characterized in that lauric acid weight percentage in said polymer is lower than 0.02%, preferably in the range lower than 0.01%.

5. An amino acid self-assembling supramolecular polymer as claimed in claim 3, wherein said polymer is substantially free of lauric acid, substantially free means lauric acid is not detectable by HPLC.

6. A sodium salt of a novel amino acid self-assembled supramolecular polymer has the following structure:

7. the sodium salt of the novel amino acid self-assembled supramolecular polymer is characterized in that N-lauroyl-L-alanyl-L-alanine sodium is used as a basic unit and is self-assembled into the supramolecular polymer through hydrogen bonds, and the weight average molecular weight data of the supramolecular polymer is 5000-500 ten thousand.

8. A preparation method of a novel amino acid self-assembled supramolecular polymer is characterized by comprising the following preparation steps:

adding a solvent, L-alanyl-L-alanine and a catalyst into the crude product of N-lauroyl-L-alanyl-L-alanine, stirring under a certain condition, cooling, filtering, washing the obtained solid, and drying to obtain the N-lauroyl-L-alanyl-L-alanine.

9. The method of claim 8, wherein the crude N-lauroyl-L-alanyl-L-alanine is prepared by the steps of:

(1) dissolving L-alanyl-L-alanine and metal inorganic base in a mixed solution of distilled water and an organic solvent, and uniformly stirring to obtain an L-alanyl-L-alanine salt solution;

(2) adding lauroyl chloride and metal inorganic alkali into the obtained L-alanyl-L-alanine salt solution in sequence, and then continuously stirring under a certain condition to obtain pasty N-lauroyl-L-alanyl-L-alanine salt;

(3) acidifying the pasty N-lauroyl-L-alanyl-L-alanine salt, gradually precipitating white solid, cooling, and filtering to obtain crude product of N-lauroyl-L-alanyl-L-alanine.

10. The method according to claim 9, wherein the molar ratio of the L-alanyl-L-alanine to the metal inorganic base in the step (1) is 1 (1-1.5); the metal inorganic base is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate; the organic solvent is selected from one or more of acetone, methanol, ethanol, acetonitrile and tetrahydrofuran; the volume ratio of the distilled water to the organic solvent is 1 (1-1.5).

11. The method according to claim 9, wherein the feed molar ratio of lauroyl chloride to L-alanyl-L-alanine in step (2) is (0.8-1): 1; the stirring conditions are as follows: the temperature is 5-50 ℃, and the time is 1-3 h; the concentration of the inorganic base is 30-80%; the metal inorganic base is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate.

12. The method according to claim 9, wherein the solvent in the step (4) is selected from acetone, methanol, ethanol, acetonitrile, tetrahydrofuran or a mixed solvent of the above solvents and water; the catalyst is selected from one or more of sulfuric acid, p-toluenesulfonic acid and an emulsifier; the molar ratio of the N-lauroyl-L-alanyl-L-alanine crude product to the solvent to the L-alanyl-L-alanine to the catalyst is 1 (5-10) to 0.1-0.2 to 0.001-0.1; the stirring conditions are as follows: the temperature is 25-100 ℃, the pressure is 5-50 kg, and the time is 1-3 h.

13. The method of claim 8, wherein the crude N-lauroyl-L-alanyl-L-alanine is prepared by the steps of:

(1) mixing N-lauroyl-L-alanine with a chlorinating reagent for reaction, cooling, adding pentan-2-one and activated carbon, sequentially carrying out decoloration, filtration and reduced pressure distillation, continuously adding an organic solvent, and dissolving acyl chloride in the N-lauroyl-L-alanine to obtain a solution of N-lauroyl-L-alanine acyl chloride;

(2) dissolving L-alanine and metal inorganic base in a mixed solution of distilled water and an organic solvent, and uniformly stirring to obtain an L-alanine salt solution;

(3) adding the solution of N-lauroyl-L-alanyl chloride obtained in the step (1) and a metal inorganic base into the L-alanine salt solution obtained above, and then continuing stirring under certain conditions to obtain a pasty N-lauroyl-L-alanyl-L-alanine salt;

(4) acidifying the pasty N-lauroyl-L-alanyl-L-alanine salt, gradually precipitating white solid, cooling, and filtering to obtain crude product of N-lauroyl-L-alanyl-L-alanine.

14. The method according to claim 13, wherein in the step (1), the molar ratio of the N-lauroyl-L-alanine to the chlorinating agent is (1-1.5): 5; the chlorinating agent can be one or more of thionyl chloride, phosphorus trichloride, triphosgene and N-chlorosuccinimide.

15. The method according to claim 13, wherein the molar ratio of the L-alanine to the inorganic base metal in the step (2) is 1 (1-1.5); the metal inorganic base is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate; the organic solvent is selected from one or more of acetone, methanol, ethanol, acetonitrile and tetrahydrofuran; the volume ratio of the distilled water to the organic solvent is 1 (1-1.5).

16. The method according to claim 13, wherein the molar ratio of the solution of N-lauroyl-L-alaninyl chloride in acetone to L-alanine charged in step (3) is (0.8-1: 1; the stirring conditions are as follows: the temperature is 5-50 ℃, and the time is 1-3 h; the concentration of the inorganic metal alkali is 30-80%; the inorganic metal base is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate.

17. A novel amino acid self-assembled supramolecular polymer, characterized in that it is obtained by the process of preparation according to any one of claims 8 to 16.

18. Use of the novel amino acid self-assembling supramolecular polymers or sodium salts of polymers as claimed in any of claims 2 to 17, characterized by applications as surfactants in the field of daily chemicals, agriculture, pharmaceutical industry.

19. A novel amino acid self-assembled supramolecular polymer or sodium salt of a polymer as claimed in any one of claims 2-7,17, characterized in that the content of N-lauroyl-L-alanine in the structure is between 0-60%.

Technical Field

The invention belongs to the technical field of amino acid type surfactant preparation, and particularly relates to a preparation method and application of a novel amino acid self-assembled supramolecular polymer.

Background

The surfactant is an essential component in many fields such as daily chemical industry, agriculture, pharmaceutical industry and the like. There are dozens of surfactants currently in use, but the surfactants mainly used are sodium dodecylbenzenesulfonate (SLS), sodium laureth sulfate (AES), and sodium laureth sulfate (K12). Since the three surfactants have been used for decades or even hundreds of years, their negative effects have gradually appeared during the use, and the effects on the safety and environment of human body are often reported.

Other surfactants such as alkyl glycoside of saccharide (APG), amino acid surfactants such as lauroyl-L-glutamic acid, lauroyl glycine, lauroyl sarcosine, etc. Although they belong to biological substance-based surfactants, which have high safety, good biodegradability and excellent skin feel, and are receiving more and more attention, these surfactants are rarely used alone as primary surfactants and often used in combination with other primary surfactants due to their poor detergency, and thus the negative problems of safety and biodegradability of daily use primary surfactants are not fundamentally solved.

N-lauroyl-L-alanine self-assembly polymer can be formed under a certain content of lauric acid, but the polymer cannot be obtained by the prior method patent, and the polymer effect is superior to that of the method patent compound, so that the N-lauroyl-L-alanyl-L-alanine is prepared by the application.

N-lauroyl-L-alanyl-L-alanine is a novel amino acid self-assembled supramolecular polymer which is synthesized on the basis of the intensive research on N-lauroyl-L-alanine, and has the basic properties of the N-lauroyl-L-alanine. However, because the structure has a group of hydrogen bonds, the whole structure is more stable and is not easy to split. And the addition of one L-alanine ensures that the whole chain is longer, the L-alanine has the same length as stearic acid and has stronger capacity of combining with oil stains than N-lauroyl-L-alanine, and a formed ring has larger space and can wrap more organic molecular compounds and biological substances, thereby changing some physical properties and chemical properties of the wrapped substances. N-lauroyl-L-alanyl-L-alanine is derived from biological materials, has natural safety and biodegradability, has more applications and has great change to human living environment.

The sodium salt of the self-assembled supermolecular polymer N-lauroyl-L-alanyl-L-alanine has two groups of hydrogen bonds, so that a two-dimensional plane structure formed by the sodium salt has stronger structural connectivity, and a reticular structure is not easy to break. And one L-alanine is added to a single molecule, so that the chain of the single molecule is longer and is similar to the length of sodium stearate with octadecane, and the detergent has stronger detergency and encapsulation.

Disclosure of Invention

In order to obtain a surfactant with good biodegradability and strong decontamination capability, the invention synthesizes a novel amino acid self-assembled supramolecular polymer on the basis of researching N-lauroyl-L-alanine, and compared with the existing surfactant, even N-lauroyl-L-alanine, the compound has more effective decontamination and bacteriostasis performance, and can be well applied to the fields of daily chemical industry, agriculture, medicine industry and the like.

The object of the present invention and the technical problem to be solved are achieved by the following technical means. The novel amino acid self-assembled supramolecular polymer provided by the invention has the following structure:

a novel monomer of amino acid self-assembly supermolecular polymer has the following structure:

wherein R is selected from H, Na or K.

The invention also relates to a novel amino acid self-assembly supermolecule polymer, which is characterized in that N-lauroyl-L-alanyl-L-alanine is used as a basic unit and is self-assembled into the supermolecule polymer through a hydrogen bond, and the weight average molecular weight data is between 5000 and 500 ten thousand.

The lauric acid content of the polymer is less than 0.02% by weight, with a preferred range of less than 0.01%.

The polymer is substantially free of lauric acid, by substantially free is meant no lauric acid is detectable by HPLC.

The invention also relates to a sodium salt of the novel amino acid self-assembled supramolecular polymer, which has the following structure:

the invention also discloses a sodium salt of the novel amino acid self-assembly supramolecular polymer, which takes N-lauroyl-L-alanyl-L-alanine sodium as a basic unit and is self-assembled into the supramolecular polymer through hydrogen bonds, and the weight average molecular weight data of the supramolecular polymer is between 5000 and 500 ten thousand.

The object of the present invention and the technical problem to be solved are also achieved by the following technical means. One proposed method according to the invention for preparing the compounds described above is as follows:

adding a solvent, L-alanyl-L-alanine and a catalyst into the crude product of N-lauroyl-L-alanyl-L-alanine, stirring under a certain condition, cooling, filtering, washing the obtained solid, and drying to obtain the N-lauroyl-L-alanyl-L-alanine.

In the aforementioned method according to the present invention, wherein the solvent is selected from acetone, methanol, ethanol, acetonitrile, tetrahydrofuran or a mixed solvent of the above solvent and water.

In the aforementioned method according to the present invention, wherein the catalyst is selected from one or more of sulfuric acid, p-toluenesulfonic acid, emulsifiers.

In the method according to the invention, the molar ratio of the crude N-lauroyl-L-alanyl-L-alanine, the solvent, the L-alanyl-L-alanine and the catalyst is 1 (5-10): (0.1-0.2): 0.001-0.1.

In the aforementioned method according to the present invention, wherein the stirring conditions are: the temperature is 25-100 ℃, the pressure is 5-50 kg, and the time is 1-3 h.

Preparing a crude product of N-lauroyl-L-alanyl-L-alanine, said process comprising the steps of:

(1) dissolving L-alanyl-L-alanine and metal inorganic base in a mixed solution of distilled water and an organic solvent, and uniformly stirring to obtain an L-alanyl-L-alanine salt solution;

(2) adding lauroyl chloride and metal inorganic alkali into the obtained L-alanyl-L-alanine salt solution in sequence, and then continuously stirring under a certain condition to obtain pasty N-lauroyl-L-alanyl-L-alanine salt;

(3) acidifying the pasty N-lauroyl-L-alanyl-L-alanine salt, gradually precipitating white solid, cooling, and filtering to obtain crude product of N-lauroyl-L-alanyl-L-alanine.

In the aforementioned method according to the present invention, wherein the molar ratio of the L-alanyl-L-alanine to the metal inorganic base in the step (1) is 1 (1 to 1.5).

In the aforementioned method according to the present invention, wherein the metal inorganic base in the step (1) is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

In the aforementioned method according to the present invention, wherein the organic solvent in the step (1) is selected from one or more of acetone, methanol, ethanol, acetonitrile, tetrahydrofuran.

In the aforementioned method according to the present invention, the volume ratio of the distilled water to the organic solvent in the step (1) is 1 (1-1.5).

In the aforementioned method according to the present invention, the feed molar ratio of lauroyl chloride to L-alanyl-L-alanine in the step (2) is (0.8-1): 1.

In the foregoing method according to the present invention, wherein the stirring conditions in the step (2) are: the temperature is 5-50 ℃, and the time is 1-3 h.

In the aforementioned method according to the present invention, wherein the concentration of the inorganic base in the step (2) is 30 to 80%.

In the aforementioned method according to the present invention, wherein the metal inorganic base in the step (2) is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

The object of the present invention and the technical problem to be solved are also achieved by the following technical means. According to the present invention there is provided a process for the preparation of a compound as described above, said process comprising the steps of:

(1) mixing N-lauroyl-L-alanine with a chlorinating reagent for reaction, cooling, adding pentan-2-one and activated carbon, sequentially carrying out decoloration, filtration and reduced pressure distillation, continuously adding an organic solvent, and dissolving acyl chloride in the N-lauroyl-L-alanine to obtain a solution of N-lauroyl-L-alanine acyl chloride;

(2) dissolving L-alanine and metal inorganic base in a mixed solution of distilled water and an organic solvent, and uniformly stirring to obtain an L-alanine salt solution;

(3) adding the acetone solution of N-lauroyl-L-alanyl chloride obtained in the step (1) and a metal inorganic base to the L-alanine salt solution obtained above, and then continuing stirring under certain conditions to obtain a paste-like N-lauroyl-L-alanyl-L-alanine salt;

(4) acidifying the pasty N-lauroyl-L-alanyl-L-alanine salt, gradually precipitating white solid, cooling, and filtering to obtain crude product of N-lauroyl-L-alanyl-L-alanine;

(5) and washing and drying the obtained crude product of the N-lauroyl-L-alanyl-L-alanine to obtain the N-lauroyl-L-alanyl-L-alanine.

In the step 1 of the method according to the invention, the addition amount of the pentan-2-one is 80-100 mL, the addition amount of the activated carbon is 1-3 g, and the addition amount of the organic solvent is 80-100 mL.

In the aforementioned method according to the invention, in the step (1), the molar ratio of the N-lauroyl-L-alanine to the chlorinating agent is (1-1.5): 5, and the chlorinating agent may be one or more of thionyl chloride, phosphorus trichloride, triphosgene and N-chlorosuccinimide.

In the aforementioned method according to the present invention, wherein the molar ratio of the L-alanine to the metal inorganic base in the step (2) is 1 (1-1.5).

In the aforementioned method according to the present invention, wherein the metal inorganic base in the step (2) is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

In the aforementioned method according to the present invention, wherein the organic solvent in the step (2) is selected from one or more of acetone, methanol, ethanol, acetonitrile, tetrahydrofuran.

In the aforementioned method according to the present invention, the volume ratio of the distilled water to the organic solvent in the step (2) is 1 (1-1.5).

In the aforementioned method according to the present invention, the molar ratio of the acetone solution of N-lauroyl-L-alanyl chloride to L-alanine fed in the step (3) is (0.8-1): 1.

In the foregoing method according to the present invention, wherein the stirring conditions in the step (3) are: the temperature is 5-50 ℃, and the time is 1-3 h.

In the aforementioned method according to the present invention, wherein the concentration of the inorganic metal base in the step (3) is 30 to 80%.

In the aforementioned method according to the present invention, wherein the inorganic metal base in the step (3) is selected from one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate.

The object of the present invention and the technical problem to be solved are also achieved by the following technical means. The compound obtained by the preparation method provided by the invention is used as a surfactant and applied to the fields of daily chemicals, agriculture and medicine industry.

The object of the present invention and the technical problem to be solved are also achieved by the following technical means. The compound provided by the invention is used as a surfactant and applied to the fields of daily chemicals, agriculture and medicine industry.

The object of the present invention and the technical problem to be solved are also achieved by the following technical means. According to the present invention, there is provided a supramolecular amino acid formed by hydrogen bonding between N-lauroyl-L-alanyl-L-alanine monomers obtained by the above-mentioned preparation method.

Compared with the prior art, the invention has the beneficial technical effects that:

1. the preparation method of the novel amino acid self-assembly supramolecular polymer has simple process steps, is prepared by condensing natural lauric acid and L-alanyl-L-alanine, is stable in normal state, is non-toxic and harmless to human bodies, can be quickly degraded into lauric acid and L-alanine when entering human bodies and being natural, has the degradation products of natural products, can be recycled, has mild reaction conditions, and is suitable for industrial production.

2. The weight percentage content of lauric acid in the self-assembled supermolecule N-lauroyl-L-alanyl-L-alanine prepared by the method is between 0.0001 percent and 0.02 percent, and the supermolecule N-lauroyl-L-alanyl-L-alanine is basically free of lauric acid, namely the content of lauric acid does not influence the structure and the performance of the N-lauroyl-L-alanyl-L-alanine, and the influence of the lauric acid on the product quality is effectively avoided.

3. The self-assembled supermolecule N-lauroyl-L-alanyl-L-alanine obtained by the method is a three-dimensional network structure, has strong oil stain adsorption and other organic matters, has the pH value of 6-7 in use, is more suitable for the pH requirement of a human body, more than 90 percent of the pH value exists in a sodium salt form, and the rest of the pH value exists in an acid form, coexists in a two-dimensional and three-dimensional manner, and is endowed with strong washing capacity, and the performances of adsorbing bacteria, pesticides, odors and the like.

4. The self-assembled supermolecule N-lauroyl-L-alanyl-L-alanine prepared by the method has stable structural performance and supermolecule property, and the molecules drive liquid components to be static in solution due to the existence of various gel factors such as hydrogen bonds, electrostatic force, hydrophobic force and pi-pi interaction to form the amino acid with a three-dimensional network space structure, so that the method has the characteristics of physical degerming, odor removal, pesticide residue removal and the like: the antibacterial agent has good antibacterial rate, and the inhibition rate of the antibacterial agent on escherichia coli, staphylococcus aureus, candida albicans and pseudomonas aeruginosa can reach 100%; pesticide residues are effectively removed, the removal rate of the methamidophos can reach 90.6 percent, and the removal rate of the acephate can reach 93.2 percent; meanwhile, the deodorant has good peculiar smell removal performance.

5. The novel amino acid self-assembly supermolecule polymer prepared by the method exists in the form of countless columns, huge gaps exist among molecules, and organic matters such as medicine molecules, pesticide residues and tiny inorganic particles can be coated. In the application of the medicine field, the N-lauroyl-L-alanyl-L-alanine can wrap medicine molecules, and slowly release effective components of the medicine under the action of enzyme to play a role of a slow release agent; in the application of the pesticide field, the N-lauroyl-L-alanyl-L-alanine can wrap the pesticide and prevent the pesticide from permeating into the plant; in the application of the cosmetic field, the physical properties of the oil can be changed after the N-lauroyl-L-alanyl-L-alanine is combined with the natural oil, and the oil is close to the oil secreted by a human body and has good experience. N-lauroyl-L-alanyl-L-alanine can encapsulate cosmetic active substance, so that the active substance is not easy to oxidize and deactivate, and the particles can be uniformly dispersed and suspended in cosmetic system.

Drawings

FIG. 1 is the structure of a compound of the present invention;

FIG. 2a is a chemical reaction formula for preparing N-lauroyl-L-alanyl-L-alanine according to the synthesis method in example 1 of the present invention;

FIG. 2b is a chemical reaction formula for preparing N-lauroyl-L-alanyl-L-alanine according to the synthesis method in example 4 of the present invention;

FIG. 2c is a chemical reaction formula for preparing N-lauroyl-L-alanyl-L-alanine according to the synthesis method in example 5 of the present invention;

FIG. 2d is a chemical reaction formula for preparing N-lauroyl-L-alanyl-L-alanine according to the synthesis method in example 7 of the present invention;

FIG. 3 is a nuclear magnetic spectrum of N-lauroyl-L-alanyl-L-alanine obtained by the synthesis method in example 1 according to the present invention;

FIG. 4 is a mass spectrum of N-lauroyl-L-alanyl-L-alanine obtained by the synthesis method in example 1 according to the present invention;

FIG. 5a is a diagram showing the structure formation of supramolecular amino acids formed by the N-lauroyl-L-alanyl-L-alanine monomer according to the synthesis method in example 1 of the present invention;

FIG. 5b is a diagram showing the formation of supramolecular amino acids from N-lauroyl-L-alanyl-L-alanine monomers obtained by the synthesis method in example 1 according to the present invention;

FIG. 6a is a 10000 times electron micrograph of N-lauroyl-L-alanyl-L-alanine obtained by the synthesis method in example 1 according to the present invention;

FIG. 6b is an electron micrograph of N-lauroyl-L-alanyl-L-alanine obtained by the synthesis method in example 1 of the present invention, which is 20000 times larger;

FIG. 6c is a 50000-fold electron micrograph of N-lauroyl-L-alanyl-L-alanine obtained according to the synthesis method in example 1 of the present invention;

FIG. 7 is a diagram showing the formation process of N-lauroyl-L-alanyl-L-alanine further forming supramolecular amino acid sodium salt according to the synthetic method in example 1 of the present invention.

FIG. 3 illustrates in the drawings: ppm is a unit of million molecules of chemical shift;

FIG. 4 is a drawing illustrating: counts vs Mass-to-chord (m/z)

Sample Name ZZXF Sample Name: ZZXF

Inj Vol sample volume

Data filename: ZZXF-07.d data filename: ZZXF-07.d

Position: position of

Injposition: sample introduction position

ACQ method: ACQ method

Instrument name

Sample Type

Comment (Comment)

Username of Username

IRM Calibration data

Accurate Time

Success of Success

PM: in the afternoon.

Detailed Description

The present invention is further illustrated by the following figures and examples, which are to be understood as merely illustrative and not restrictive. Furthermore, it should be understood that various changes and modifications of the present invention may be made by those skilled in the art after reading the teachings herein, and such equivalents may fall within the scope of the invention as defined in the appended claims.

It will be understood by those skilled in the art that the term "lauric acid-free N-lauroyl-L-alanine" as used herein is not absolutely free of lauric acid, but means that the lauric acid content is between 0.0001% and 0.02%, as measured, for example, by high performance liquid chromatography (equipped with a UV detector; column: ODS-2HYPERSIL C18250 x 4.6mm 5 μm; mobile phase vacuum filtration degasser and 0.45 μm organic filter), i.e.the lauric acid content does not affect the nature and structure of N-lauroyl-L-alanine.

One embodiment of the present invention provides a compound having the structure:

wherein R is selected from H, Na or K.

Yet another embodiment of the present invention provides a method of preparing a compound as described above, comprising the steps of: (1) dissolving L-alanyl-L-alanine and metal inorganic base in a mixed solution of distilled water and an organic solvent, and uniformly stirring to obtain an L-alanyl-L-alanine salt solution; (2) sequentially adding lauroyl chloride and metal inorganic base into the obtained L-alanyl-L-alanine salt solution at 5-50 ℃ to enable the pH of a reaction system to be 8-10, and then continuously stirring under certain conditions to obtain pasty N-lauroyl-L-alanyl-L-alanine salt; (3) acidifying the obtained pasty N-lauroyl-L-alanyl-L-alanine salt to a pH value of 3-4, gradually precipitating a white solid, then placing the white solid in an ice bath for 1-3 h, and filtering to obtain a crude product of N-lauroyl-L-alanyl-L-alanine; (4) adding a solvent, L-alanyl-L-alanine and a catalyst into the obtained crude product of the N-lauroyl-L-alanyl-L-alanine, stirring under a certain condition, cooling, filtering, washing the obtained solid, and drying to obtain the N-lauroyl-L-alanyl-L-alanine.

Another embodiment of the present invention is directed to a method of preparing the compound, the method comprising the steps of: (1) dissolving N-lauroyl-L-alanine and triphosgene in chloroform, adding a small amount of catalyst for reaction, and evaporating excessive chloroform to obtain N-lauroyl-L-alanyl chloride; (2) dissolving L-alanine methyl ester hydrochloride, water-soluble organic alkali and the obtained N-lauroyl-L-alanyl chloride in acetone, reacting under a certain condition, heating to room temperature, continuing to react for 4-6 h, and evaporating redundant acetone after the reaction is finished to obtain N-lauroyl-L-alanyl-L-alanine methyl ester; (3) dissolving the obtained N-lauroyl-L-alanyl-L-alanine methyl ester and metal inorganic alkali in a mixed solution of distilled water and an organic solvent for reaction for 4-8 h, and evaporating redundant organic solvent after the reaction is finished to obtain pasty N-lauroyl-L-alanyl-L-alanine salt; (4) acidifying the obtained pasty N-lauroyl-L-alanyl-L-alanine salt to a pH value of 3-4, gradually precipitating a white solid, then placing the white solid in an ice bath for 1-3 h, and filtering to obtain a crude product of N-lauroyl-L-alanyl-L-alanine; (5) and washing and drying the obtained crude product of the N-lauroyl-L-alanyl-L-alanine to obtain the N-lauroyl-L-alanyl-L-alanine.

Yet another embodiment of the present invention provides a method for preparing the compound, the method comprising the steps of: (1) dissolving N-lauroyl-L-alanine and triphosgene in chloroform, adding a small amount of catalyst for reaction, and evaporating excessive chloroform to obtain N-lauroyl-L-alanyl chloride; (2) dissolving L-alanine methyl ester hydrochloride, water-soluble organic alkali and the obtained N-lauroyl-L-alanyl chloride in acetone, reacting under a certain condition, heating to room temperature, continuing to react for 4-6 h, and evaporating redundant acetone after the reaction is finished to obtain N-lauroyl-L-alanyl-L-alanine methyl ester; (3) dissolving the obtained N-lauroyl-L-alanyl-L-alanine methyl ester and metal inorganic alkali in a mixed solution of distilled water and an organic solvent for reaction for 4-8 h, and evaporating redundant organic solvent after the reaction is finished to obtain pasty N-lauroyl-L-alanyl-L-alanine salt; (4) acidifying the obtained pasty N-lauroyl-L-alanyl-L-alanine salt to a pH value of 3-4, gradually precipitating a white solid, then placing the white solid in an ice bath for 1-3 h, and filtering to obtain a crude product of N-lauroyl-L-alanyl-L-alanine; (5) and washing and drying the obtained crude product of the N-lauroyl-L-alanyl-L-alanine to obtain the N-lauroyl-L-alanyl-L-alanine.

Still another embodiment of the present invention is to provide a supramolecular amino acid formed by hydrogen bonding between N-lauroyl-L-alanyl-L-alanine monomers obtained by any one of the aforementioned preparation methods. The above-described embodiments of the present invention will be further described with reference to examples.