A biomimetic temperature-sensitive composite membrane for chiral separation of phenylalanine, and a preparation method and application thereof

Abstract

The application discloses a kind of for phenylalanine chiral separation biomimetic temperature-sensitive composite membrane and preparation method and application, the present application is with polymer film as substrate, by the method for preparing biomimetic temperature-sensitive hydrogel of chemical crosslinking.Biomimetic temperature-sensitive composite membrane includes the following steps: polymer film is placed in containing o-diphenol group, glycosyl material and temperature-sensitive substance alkaline solution, after a period of time, it is taken out, after deionized water is washed, place in cross-flow membrane filter, chiral separation of phenylalanine can be realized.The modified membrane piece under the operating pressure of 50 kpa and the separation temperature of 40 DEG C, the separation factor of D / L-phenylalanine can reach above 3, maintain higher permeation flux, and anti-pollution performance is significantly enhanced.The preparation method of the biomimetic temperature-sensitive composite membrane disclosed in the application is simple and mild, raw material is cheap and easy to obtain, the prepared biomimetic temperature-sensitive composite membrane has good temperature sensitivity, anti-pollution and excellent chiral separation effect, with the characteristics of resource-saving and environment-friendly.

Description

Technical Field

[0001] This invention belongs to the field of membrane separation, and particularly relates to a biomimetic temperature-sensitive composite membrane for the chiral separation of phenylalanine, its preparation method, and its application. Background Technology

[0002] Chirality refers to a structure that is not exactly identical to its mirror image. Most important artificial drug compounds produced through chemical reactions are chiral. Chirality is widespread in nature, closely related to human production and daily life, and has a significant impact on the development of the biomedical field. These two enantiomers exist as dextrorotatory or levorotatory molecules, possessing almost identical physical and chemical properties, but may have completely different physiological activities. One enantiomer may be effective as a drug, while the other may be ineffective or even toxic. Therefore, the identification and resolution of chiral substances is of great significance to various fields. Chiral separation has become an indispensable process in the production of all chiral drugs, requiring greater precision and efficiency to meet health and drug safety requirements.

[0003] However, due to the similarity in structure and properties of enantiomers, optical separation of enantiomers has always been one of the most challenging separation tasks. For example, amino acids are essential substances for the human body, participating in biochemical metabolism. Most amino acids have chiral structures, and artificially produced amino acids are generally D-form, which needs to be converted into L-form for the body to utilize and absorb. However, excessive D-form amino acids can be harmful to the body, and in severe cases, can cause poisoning. Therefore, the separation of amino acids has broad application prospects. Currently, chiral separation methods mainly include recrystallization, chromatography, enzymatic methods, and membrane separation. Membrane separation technology has significant advantages in terms of production capacity, operating conditions, and cost. However, most existing membrane materials suffer from high manufacturing costs, cumbersome manufacturing processes, and lack of reusability, and their separation efficiency needs further improvement.

[0004] Thermosensitive materials are widely used in biological and pharmaceutical sciences. Their temperature-sensitive deformation properties make them frequently used in the fabrication of capsules, bone-like materials, and other similar products. Loading thermosensitive materials onto membranes to impart temperature-sensitive properties allows for the reuse of membrane materials, reducing costs and conserving resources. These materials hold immense application potential for the future. In addition to their temperature-sensitive properties, thermosensitive materials also possess selective recognition characteristics. In recent years, the combination of thermosensitive materials with ion imprinting technology to create functional ion-discriminating materials has gained significant attention. Capillary gel-free sieving electrophoresis using thermosensitive materials as sieving media can separate DNA. Stimulus-responsive microgel-based composite materials made from thermosensitive materials can selectively identify metal ions in industrial wastewater. In the life sciences, the combination of nano-photocatalysts and thermosensitive materials to create composite thermosensitive systems enables the enrichment and separation of uranium. This invention crosslinks thermosensitive materials onto membranes to achieve the separation of chiral substances, a concept that will open new avenues for chiral separation. Summary of the Invention

[0005] The purpose of this invention is to provide a biomimetic temperature-sensitive composite membrane for the chiral separation of phenylalanine, its preparation method, and its application. This invention utilizes temperature-sensitive materials to achieve membrane separation of phenylalanine. Using a polymer membrane as a substrate, a biomimetic temperature-sensitive hydrogel is prepared through chemical cross-linking. Under an operating pressure of 50 kPa and a separation temperature of 40°C, the separation factor of D / L-phenylalanine can reach above 3, maintaining a high permeation flux and significantly enhancing antifouling performance. The preparation method of the biomimetic temperature-sensitive composite membrane disclosed in this invention is simple and mild, using inexpensive and readily available raw materials. The prepared biomimetic temperature-sensitive composite membrane possesses good temperature sensitivity, antifouling properties, and excellent chiral separation effect, exhibiting resource-saving and environmentally friendly characteristics, and can be mass-produced.

[0006] The technical solution adopted in this invention is as follows:

[0007] A method for preparing a biomimetic temperature-sensitive composite membrane for chiral separation of phenylalanine includes the following steps:

[0008] 1) Dissolve the biomimetic material containing o-diphenol in an alkaline solution to obtain a homogeneous solution, and add a glycosyl chiral recognition material and a thermosensitive substance to it and stir until homogeneous;

[0009] 2) Immerse the polymer film in the solution of step 1), and then react it fully in a water bath at 20℃~50℃ for 1~48h;

[0010] 3) After the reaction is complete, the polymer membrane is removed and rinsed with deionized water to remove unreacted substances from the membrane surface, thus obtaining the biomimetic temperature-sensitive composite membrane for chiral separation of phenylalanine.

[0011] Further, the biomimetic substance containing o-diphenol mentioned in step 1) includes at least one of dopamine, catechol, tannic acid, gallic acid, tea polyphenols, and caffeic acid, and its concentration in alkaline solution is 1-7 g / L.

[0012] Further, in step 1), the alkaline solution is a Tris buffer solution, NaOH solution, or KOH solution with a pH of 8-10, preferably a Tris buffer solution.

[0013] Further, the glycosyl chiral recognition material mentioned in step 1) includes at least one of chitosan, cellulose, starch, β-cyclodextrin and its derivatives, and the mass ratio of the glycosyl chiral recognition material to the biomimetic substance containing o-diphenol is 0.1-2.5:1, preferably 0.125-1:1.

[0014] Further, in step 1), the thermosensitive substance includes at least one of N-isopropylacrylamide and sodium β-glycerophosphate, and its mass ratio with the biomimetic substance containing o-diphenol is 0.1-2.5:1, preferably 0.125-1:1.

[0015] Further, the polymer membrane mentioned in step 2) is a polysulfone ultrafiltration membrane, a polyether ultrafiltration membrane, a polyethersulfone ultrafiltration membrane, a polyvinylidene fluoride membrane, or a polyethylene membrane.

[0016] Furthermore, in step 2), the reaction temperature is 25-35℃ and the reaction time is 1-5h.

[0017] The present invention also provides the application of the aforementioned biomimetic temperature-sensitive composite membrane in the chiral separation of phenylalanine. The biomimetic temperature-sensitive composite membrane is loaded into a cross-flow membrane device, and an aqueous solution containing serum albumin and phenylalanine is used as the feed liquid. The chiral separation of phenylalanine is achieved by cross-flow filtration.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) This invention provides a biomimetic temperature-sensitive composite membrane for the chiral separation of phenylalanine and its preparation method. Compared with the preparation of other chiral separation membranes, the method disclosed in this invention is simple, easy to implement and has low manufacturing cost. The chiral separation of the composite membrane has temperature sensitivity, high efficiency, high flux and strong anti-fouling ability.

[0020] (2) The preparation conditions of the present invention are mild and do not require high temperature, high pressure or vacuum conditions. The cross-linking of the membrane can be achieved by simply shaking.

[0021] (3) The method described in this invention is green and environmentally friendly, and non-toxic and harmless, making it suitable for drug separation. Attached Figure Description

[0022] Figure 1This is a scanning electron microscope image of a commercial membrane;

[0023] Figure 2 This is a scanning electron microscope image of the modified membrane prepared in Example 3 of the present invention;

[0024] Figure 3 The results show a comparison of membrane flux between commercial membranes and the modified membrane prepared in Example 3 of this invention, which are used to test the separation effect. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0026] In this embodiment of the invention, chitosan was purchased from www.macklin.cn, and bovine serum albumin was purchased from www.shyuanye.com. The polyethersulfone ultrafiltration membrane, with a molecular weight of 50,000 Dalton, was purchased from Zhongke Ruiyang Membrane Technology Co., Ltd. The commercial membrane used as a control (i.e., the original membrane) was purchased from Zhongke Ruiyang Membrane Technology Co., Ltd., model number: UE050.

[0027] The separation factor for L / D-phenylalanine is calculated as follows: (concentration of L-phenylalanine in effluent / concentration of D-phenylalanine in effluent) ÷ (concentration of L-phenylalanine in influent / concentration of D-phenylalanine in influent).

[0028] Example 1

[0029] A biomimetic temperature-sensitive composite membrane for chiral separation of phenylalanine and its preparation method are as follows:

[0030] 0.2 g of dopamine and 0.8 g of tannic acid were dissolved in 150 ml of Tris buffer solution with pH = 8.5. 1 g of N-isopropylacrylamide and 1 g of β-cyclodextrin were added to the aqueous solution. The polyethersulfone ultrafiltration membrane was immersed in this solution and reacted at 35 °C for 3 h. The modified membrane was then rinsed with deionized water to obtain the modified membrane of the present invention.

[0031] The separation performance of the modified membrane in Example 1 was evaluated using a cross-flow filtration system. An aqueous solution containing phenylalanine and bovine serum albumin (BSA) was used as the feed solution. The concentrations of phenylalanine and BSA in the feed solution were 0.5 mM and 0.1 mM, respectively. Phenylalanine included both D- and L-configurations, and the molar ratio of D-phenylalanine to L-phenylalanine was 1:1, meaning that the concentrations of both D-phenylalanine and L-phenylalanine in the feed solution were 0.25 mM. Permeate was collected on the other side of the membrane under an applied test pressure. The test conditions were set as follows: feed solution temperature 40°C and test pressure 50 kPa. When the membrane's permeate selectivity was formally tested, the result after 100 minutes was: the flux of the feed solution through the membrane was 3.32 L / m³.2 The separation factor for L / D-phenylalanine was 1.22, and the effluent concentration of D-phenylalanine was 18 mg / L.

[0032] Example 2

[0033] A method for preparing a biomimetic temperature-sensitive composite membrane for the chiral separation of phenylalanine, comprising the following steps:

[0034] 0.2 g of dopamine was dissolved in 150 ml of Tris buffer solution with pH = 8.5. 0.5 g of N-isopropylacrylamide and 0.5 g of chitosan were added to the aqueous solution. The polyethersulfone ultrafiltration membrane was immersed in this solution and reacted at 35 °C for 1 h. The modified membrane was then rinsed with deionized water to obtain the modified membrane of the present invention.

[0035] The separation performance of the modified membrane in Example 2 was evaluated using a cross-flow filtration system. The test conditions were repeated for Example 1, and the results after 100 minutes of testing showed that the flux of the feed liquid through the membrane was 5.86 L / m. 2 The chiral separation factor of L / D-phenylalanine is 1.03, and the effluent concentration of D-phenylalanine is 21 mg / L.

[0036] Example 3

[0037] 0.2 g of dopamine and 0.6 g of tannic acid were dissolved in 150 ml of Tris buffer solution at pH 8.5. 0.1 g of N-isopropylacrylamide and 0.1 g of chitosan were added to this aqueous solution. A polyethersulfone ultrafiltration membrane was immersed in this solution and reacted at 35°C for 1 hour. The modified membrane was then rinsed with deionized water to obtain the modified membrane of this invention. The separation performance of the modified membrane of Example 3 was evaluated using a cross-flow filtration system. The test conditions were repeated in Example 1. The test results for 100 min showed that the flux of the feed liquid through the membrane was 5.69 L / m³. 2 The chiral separation factor of L / D-phenylalanine is 3.46, and the effluent concentration of D-phenylalanine is 6 mg / L.

[0038] The scanning electron microscope image of the modified membrane in Example 3 of this invention is shown below. Figure 2 Scanning electron microscope images of commercial membranes are shown below. Figure 1 ,pass Figure 2 and Figure 1 The comparison shows that the pores of the modified membrane in Example 3 are more uniformly distributed and have a more consistent pore size.

[0039] In addition, the membrane flux comparison results of the separation effect tests between the commercial membrane and the modified membrane prepared in Example 3 of this invention, according to the above test conditions, are shown in the figure. Figure 3As can be seen, the membrane flux dropped sharply during commercial membrane testing, while the service life of the modified membrane in Example 3 of this invention was greatly improved.

[0040] Example 4

[0041] Add 0.1g N-isopropylacrylamide and 0.1g chitosan to 150mL of deionized water, immerse the polyethersulfone ultrafiltration membrane in this solution and react fully at 35°C for 1 hour. Then rinse the modified membrane with deionized water to obtain the modified membrane of the present invention.

[0042] The separation performance of the modified membrane in Example 4 was evaluated using a cross-flow filtration system. The test conditions were the same as in Example 1, and the results after 100 minutes of testing showed that the flux of the feed liquid through the membrane was 3.58 L / m. 2 The chiral separation factor of L / D-phenylalanine was 0.96, and the effluent concentration of D-phenylalanine was 23 mg / L.

[0043] The test results of the modified membranes in Examples 1-4 are summarized in Table 1.

[0044] Table 1

[0045] Grouping Separation factor α (D / L) <![CDATA[Flux L / m 2 / h]]> Example 1 1.22 3.32 Example 2 1.03 5.86 Example 3 3.46 5.69 Example 4 0.96 3.58

[0046] As can be seen from Table 1, the separation performance of the modified membrane in Example 3 is significantly higher than that in Examples 1-2. This may be because chitosan has viscosity and agglomeration properties, and a larger amount of chitosan may not yield good experimental results. Furthermore, a comparison between Example 4 and Example 3 shows that the biomimetic material containing o-diphenol and the alkaline solution have a significant effect on improving the membrane's separation performance.

[0047] The contents described in this specification are merely an enumeration of the implementation forms of the inventive concept, and the scope of protection of this invention should not be regarded as limited to the specific forms described in the embodiments.

Claims

1. Application of a biomimetic temperature-sensitive composite membrane in chiral separation of phenylalanine, characterized in that The preparation method of the biomimetic temperature-sensitive composite membrane comprises the following steps: 1) dissolving a biomimetic substance containing o-diphenol in an alkaline solution to obtain a homogeneous solution, and adding a sugar-based chiral recognition material and a temperature-sensitive substance to the solution and stirring uniformly; 2) immersing a polymer membrane piece in the solution of step 1) and then fully reacting in a water bath environment at 20-50 DEG C for 1-48 h; 3) after the reaction is completed, the polymer membrane piece is taken out and washed with deionized water to remove the unreacted substances from the membrane surface, thereby obtaining a biomimetic temperature-sensitive composite membrane for chiral separation of phenylalanine; The biomimetic substance containing o-diphenol in step 1) comprises at least one of dopamine, catechol, tannic acid, gallic acid, tea polyphenol and coffee acid. The alkaline solution in step 1) is a Tris buffer solution with a pH of 8-10. The sugar-based chiral recognition material in step 1) comprises at least one of chitosan and its derivatives, and the mass ratio of the sugar-based chiral recognition material to the biomimetic substance containing o-diphenol is 0.1-2.5:

1.

2. Use according to claim 1, wherein The concentration of the biomimetic substance containing o-diphenol in the alkaline solution in step 1) is 1-7 g / L.

3. The use according to claim 1, wherein In step 1), the mass ratio of the sugar-based chiral recognition material to the biomimetic substance containing o-diphenol is 0.125-1:

1.

4. The use according to claim 1, characterized in that The temperature-sensitive substance in step 1) comprises at least one of N-isopropyl acrylamide and beta-glycerophosphate sodium, and the mass ratio of the temperature-sensitive substance to the biomimetic substance containing o-diphenol is 0.1-2.5:

1.

5. The use according to claim 4, wherein In step 1), the mass ratio of the temperature-sensitive substance to the biomimetic substance containing o-diphenol is 0.125-1:

1.

6. The use according to claim 1, characterized in that The polymer membrane piece in step 2) is a polysulfone ultrafiltration membrane piece, a polyether ultrafiltration membrane piece, a polyether sulfone ultrafiltration membrane piece, a polyvinylidene fluoride membrane piece or a polyethylene membrane piece.

7. The use according to claim 1, wherein In step 2), the reaction temperature is 25-35 DEG C, and the reaction time is 1-5 h.

8. The use according to claim 1, characterized in that The biomimetic temperature-sensitive composite membrane is loaded into a cross-flow membrane device, an aqueous solution containing serum albumin and phenylalanine is used as a feed liquid, and chiral separation of phenylalanine is realized by cross-flow filtration.

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