N-boc-l-phenylalanine molecularly imprinted polymer, its preparation method and application

Abstract

The application discloses an N-Boc-L-phenylalanine molecular imprinting polymer and a preparation method and application thereof. The N-Boc-L-phenylalanine molecular imprinting polymer is prepared by using a bulk polymerization method, taking N-Boc-L-phenylalanine as a template molecule and allylamine as a functional monomer, and under the participation of a crosslinking agent and an initiator. The molecular imprinting polymer has specific recognition ability to N-Boc-L-phenylalanine. The maximum adsorption capacity of the molecular imprinting polymer to N-Boc-L-phenylalanine reaches 14.50 mg / g, and the imprinting factor IF value is as high as 10.33. The adsorption amount of the molecular imprinting polymer to N-Boc-L-phenylalanine is significantly higher than that to N-Boc-D-phenylalanine, and the molecular imprinting polymer has good chiral recognition ability. The molecular imprinting polymer can be used for selective recognition, adsorption and enrichment of N-Boc-L-phenylalanine.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to an N-Boc-L-phenylalanine molecularly imprinted polymer, its preparation method, and its applications. Background Technology

[0002] N-Boc-L-phenylalanine (N-tert-butoxycarbonyl-L-phenylalanine) is an important raw material for the synthesis of peptides, pharmaceutical intermediates, and chiral catalysts, and is widely used in the pharmaceutical and chemical industries. Studies have shown that the selective separation and purification of N-Boc-L-phenylalanine in complex systems (such as fermentation broth, enzyme-catalyzed reaction solutions, and mixtures of peptide synthesis byproducts) has always been a challenge for industry. Traditional separation methods, such as solvent extraction, recrystallization, and column chromatography, suffer from problems such as cumbersome operation, high consumption of organic solvents, low yields, or insufficient selectivity, making it difficult to meet the demands of green chemistry and efficient production.

[0003] Molecular imprinting technology (MIT) is a technique for preparing polymers with excellent molecular recognition properties. Due to its high recognition and selectivity, it offers significant advantages for the separation and enrichment of target molecules in complex sample matrices such as food, environment, and biological samples. In recent years, MIT has been reported to be applied to the separation of amino acids and their derivatives. However, research on molecularly imprinted materials for N-Boc protected amino acids is still insufficient. For example, current techniques for preparing N-Boc protected amino acid molecularly imprinted materials often employ precipitation polymerization and acrylamide functional monomers. Acrylamide can only interact with template molecules through hydrogen bonds, resulting in limited binding strength and insufficient recognition performance of the imprinted polymer. Summary of the Invention

[0004] To address the aforementioned shortcomings of existing technologies, the present invention aims to provide an N-Boc-L-phenylalanine molecularly imprinted polymer, its preparation method, and its applications, thereby solving the problems of cumbersome separation and purification operations, high organic solvent consumption, low yield, insufficient selectivity, low adsorption capacity, and insufficient affinity of binding sites in existing molecularly imprinted materials.

[0005] This invention uses allylamine as the functional monomer, leveraging its basic amino group to form both ionic and hydrogen bonds with the carboxyl group of N-Boc-L-phenylalanine, thereby enhancing the stability of the template-monomer pre-assembled complex. Furthermore, this invention employs bulk polymerization instead of traditional precipitation polymerization, eliminating the need for complex precipitation conditions and solvent systems. It is simple to operate, requires minimal equipment, and is suitable for rapid laboratory-scale preparation and condition screening. During polymerization, the pre-assembled structure of the template molecule and functional monomer is less likely to be destroyed, resulting in a more complete and regular imprinted cavity structure, which is beneficial for improving specific recognition capabilities.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A method for preparing a molecularly imprinted polymer that selectively adsorbs N-Boc-L-phenylalanine includes the following steps:

[0008] S1: Mix the template molecule N-Boc-L-phenylalanine with the porogen, then add the functional monomer allylamine, and perform pre-assembly to obtain a prepolymer solution;

[0009] S2: Add crosslinking agent ethylene glycol dimethacrylate and initiator azobisisobutyronitrile to the prepolymerization solution, and carry out the polymerization reaction under a protective atmosphere to obtain a solid polymer;

[0010] S3: The template molecules are removed by eluting the obtained solid polymer and then dried to obtain N-Boc-L-phenylalanine molecularly imprinted polymer; wherein, the molar ratio of template molecule: functional monomer: crosslinking agent in step S1 is 1:(1~8):(10~50).

[0011] This invention is the first to use allylamine as a functional monomer. The basic amino group of allylamine can form both ionic and hydrogen bonds with the carboxyl group of the template molecule, significantly enhancing the stability of the template-monomer pre-assembled complex. Simultaneously, this invention employs bulk polymerization, and the subsequent grinding process exposes more imprinted cavities within the polymer, effectively increasing the number of specific recognition sites. Based on these synergistic effects, the molecularly imprinted polymer prepared by this invention exhibits higher imprinting factors and adsorption capacities.

[0012] The molar ratio of template molecule to functional monomer is 1:(1~8).

[0013] Preferably, the molar ratio of template molecule: functional monomer: crosslinking agent is 1:(1~8):(10~50).

[0014] Preferably, the crosslinking agent in step S2 is ethylene glycol dimethacrylate.

[0015] Preferably, the initiator in step S2 is azobisisobutyronitrile, and the molar ratio of the initiator to the template molecule is 0.15~0.8:1.

[0016] Preferably, the polymerization reaction temperature in step S2 is 55~65℃, and the reaction time is 12~28 h.

[0017] Preferably, the protective atmosphere in step S2 is nitrogen or argon, and the polymerization process is carried out under stirring at a stirring speed of 200 rpm.

[0018] Preferably, in step S3, a template removal agent is used for elution. The template removal agent is a mixture of methanol and 0.1% sodium hydroxide aqueous solution, with a volume ratio of 1 to 9:1.

[0019] Preferably, after drying in step S3, the material is ground through a 100-500 mesh sieve; the drying temperature is 60-100℃ and the drying time is 6-24h.

[0020] This invention also claims protection for the N-Boc-L-phenylalanine molecularly imprinted polymer obtained by the above preparation method.

[0021] Furthermore, the molecularly imprinted polymer is used for the selective recognition, chiral separation, adsorption, and enrichment of N-Boc-L-phenylalanine.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The preparation method provided by this invention is simple to operate and low in cost. The resulting molecularly imprinted polymer has uniform particle size distribution, high adsorption capacity, fast mass transfer rate, strong specificity, good stability, and can be reused.

[0024] This invention employs bulk polymerization, using N-Boc-L-phenylalanine as the template molecule and allylamine as the functional monomer. Utilizing the hydrogen bonds and other interactions between the template molecule and the functional monomer, and under the action of the crosslinking agent ethylene glycol dimethacrylate, a polymer with a three-dimensional network structure is generated. After eluting the template molecule, holes are exposed that can both match the spatial size of N-Boc-L-phenylalanine and interact with it. These holes significantly reduce the recognition ability of N-Boc-D-phenylalanine, thus achieving the construction of a molecularly imprinted polymer material that selectively recognizes N-Boc-L-phenylalanine. The molecularly imprinted polymer material prepared by this invention achieves an imprinting factor of 10.33 and a maximum adsorption capacity of 14.50 mg / g for N-Boc-L-phenylalanine, demonstrating significant adsorption performance. Attached Figure Description

[0025] Figure 1These are the adsorption performance test results of MIPS and NIPS prepared in different solvents according to the present invention in different solvents;

[0026] Figure 2 This is a saturated adsorption analysis of Example 1 and Comparative Example 1;

[0027] Figure 3 This is the infrared spectral characterization of Example 1. Detailed Implementation

[0028] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0029] The terms “comprising,” “including,” “having,” “containing,” or any other variations thereof, as used herein, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not limited to those elements and may also include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0030] "Optional" or "any one" means that the matter or event described thereafter may or may not occur, and the description includes both the possibility that the event will occur and the possibility that the event will not occur.

[0031] The indefinite articles “a” and “an” preceding an element or component of this invention do not impose any limitation on the quantity (i.e., number of occurrences) of the element or component. Therefore, “an” or “a” should be interpreted as including one or at least one, and the singular form of an element or component also includes the plural form, unless the quantity clearly refers only to the singular form.

[0032] The terms "one embodiment," "some embodiments," "exemplary," "specific example," or "some examples," etc., used in this invention refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this document, the illustrative expressions of the above terms are not necessarily directed at the same embodiment or example.

[0033] The numerical range described in this invention includes not only the point values ​​listed in the embodiments, but also any point values ​​not listed within the numerical range described in this invention. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0034] In the following examples, unless otherwise specified, all reagents and consumables were purchased from conventional reagent manufacturers in the field.

[0035] This embodiment provides a method for preparing a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine, specifically including the following steps:

[0036] S1. The template molecule N-Boc-L-phenylalanine is mixed with a porogen and a functional monomer to carry out a prepolymerization reaction to obtain a prepolymer product;

[0037] S2. Add a crosslinking agent and an initiator to the prepolymer product, and carry out a polymerization reaction under a protective atmosphere to obtain the polymer;

[0038] S3. Use a template removal agent to elute the polymer product, remove the template molecules in the polymer product, and obtain a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine.

[0039] S4. The polymer obtained in step S3 is ground and then sieved to obtain a fine powder material.

[0040] The molecularly imprinted polymer material prepared in this embodiment is a polymer material synthesized using molecular imprinting technology that selectively recognizes and adsorbs specific template molecules and their structural analogs. During its preparation, the template molecule and functional monomer form multiple binding sites and are memorized. When the template molecule is removed, the polymer forms cavities with multiple binding sites that match the spatial configuration of the template molecule, thereby enabling it to specifically recognize the template molecule and its structural analogs.

[0041] In this embodiment, the template molecule is N-Boc-L-phenylalanine;

[0042] In this embodiment, the molar ratio of template molecule, functional monomer, and crosslinking agent is 1:(1~8):(10~50);

[0043] In this embodiment, the functional monomer is allylamine;

[0044] In this embodiment, the crosslinking agent is ethylene glycol dimethacrylate;

[0045] In some specific implementations, the molar ratio of template molecule to functional monomer is 1:(1 ~ 8).

[0046] In one specific embodiment, the molar ratio of template molecule to functional monomer is 1:4. When the molar ratio of template molecule to functional monomer is 1:4, the prepared molecularly imprinted polymer material has good adsorption performance and selectivity.

[0047] In some specific embodiments, the porogen is any one of dichloromethane, methanol, chloroform, dimethyl sulfoxide, acetonitrile, acetone, toluene, and 1,4-dioxane.

[0048] In one specific embodiment, the pore-forming agent is acetonitrile.

[0049] In some specific embodiments, the molar ratio of template molecules to crosslinking agents is 1:(10~50).

[0050] In one specific embodiment, the molar ratio of template molecules to crosslinking agents is 1:20. When the molar ratio of template molecules to crosslinking agents is 1:20, the adsorption performance and selectivity of the prepared molecularly imprinted polymer material are further improved.

[0051] In some specific embodiments, the initiator is azobisisobutyronitrile, and the dosage is 10 to 50 mg.

[0052] In one specific embodiment, the amount of initiator azobisisobutyronitrile is 10 mg, which further improves the adsorption performance and selectivity of the molecularly imprinted polymer material prepared.

[0053] In some specific implementations, the polymerization reaction in step S2 needs to be carried out under a protective atmosphere. As an example, the protective atmosphere may be nitrogen or argon.

[0054] In some specific implementations, the polymerization reaction time in step S2 is 12 to 28 hours. As an example, the polymerization reaction time can be 12 hours, 16 hours, 20 hours, 24 hours, or 28 hours, as long as the polymerization reaction time is within this range.

[0055] In one specific embodiment, the polymerization reaction time is 24 hours. When the polymerization reaction time is 24 hours, the prepared molecularly imprinted polymer material has good adsorption performance and selectivity.

[0056] In some specific embodiments, the template removal agent in step S3 is a mixed solution of methanol and sodium hydroxide aqueous solution. The volume ratio of methanol to 0.1 mol / L sodium hydroxide aqueous solution is (5~10):1. As an example, the volume ratio of methanol to 0.1 mol / L sodium hydroxide aqueous solution can be 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1, as long as the volume ratio of methanol to 0.1 mol / L sodium hydroxide aqueous solution is within this range.

[0057] In one specific embodiment, the volume ratio of methanol to 0.1 mol / L sodium hydroxide aqueous solution is 9:1. When the volume ratio of methanol to 0.1 mol / L sodium hydroxide aqueous solution is 9:1, the elution effect of template molecules is better.

[0058] In some specific embodiments, after elution in step S3, the polymer material needs to be vacuum dried at a temperature of 50~70°C for 12~24 hours. As an example, the drying temperature can be 50°C, 60°C, or 70°C, and the drying time can be 12 hours, 18 hours, or 24 hours, as long as the drying conditions are within this range.

[0059] In one specific implementation, the drying temperature is 70°C and the drying time is 24 hours.

[0060] In some specific embodiments, the dried polymer material needs to be ground to a mesh size of 100-500. For example, the mesh size can be 100, 200, 300, 400, or 500, as long as it falls within this range. In one specific embodiment, the mesh size is 300.

[0061] The present invention will be further illustrated below through specific embodiments:

[0062] Example 1

[0063] 0.4 mmol of template molecule N-Boc-L-phenylalanine was mixed with 2 mL of porogen acetonitrile and 1.6 mmol of functional monomer allylamine to undergo a prepolymerization reaction to obtain a prepolymer product. 8 mmol of crosslinking agent ethylene glycol dimethacrylate and 10 mg of initiator azobisisobutyronitrile were added to the prepolymer product, and polymerization was carried out at 60 °C for 24 h under an argon atmosphere to obtain a polymer. The polymer product was eluted with a template removal agent to remove the template molecules, yielding a molecularly imprinted polymer material selectively adsorbing N-Boc-L-phenylalanine. The template removal agent was a mixed solution of methanol and 0.1 mol / L sodium hydroxide aqueous solution, with a volume ratio of methanol to 0.1 mol / L sodium hydroxide aqueous solution of 9:1. The mixture was then ground and passed through a 300-mesh standard sieve. This yielded the molecularly imprinted polymer material selectively adsorbing N-Boc-L-phenylalanine.

[0064] Example 2

[0065] This embodiment provides a method for preparing a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine. The only difference from Example 1 is that the porogen is replaced with dimethyl sulfoxide.

[0066] Example 3

[0067] This embodiment provides a method for preparing a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine. The only difference from Example 1 is that the pore-forming agent is replaced with methanol.

[0068] Example 4

[0069] This embodiment provides a method for preparing a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine. The only difference from Example 1 is that the porogen is replaced with dichloromethane.

[0070] Example 5

[0071] This embodiment provides a method for preparing a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine. The only difference from Example 1 is that the porogen is replaced with chloroform.

[0072] Example 6

[0073] This embodiment provides a method for preparing a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine. The only difference from Example 1 is that the pore-forming agent is replaced with toluene.

[0074] Example 7

[0075] This embodiment provides a method for preparing a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine. The only difference from Example 1 is that the porogen is replaced with 1,4-dioxane.

[0076] Example 8

[0077] This embodiment provides a method for preparing a molecularly imprinted polymer material that selectively adsorbs N-Boc-L-phenylalanine. The only difference from Example 1 is that the pore-forming agent is replaced with acetone.

[0078] Comparative Example 1

[0079] This comparative example provides a method for preparing a non-imprinted polymer material, which differs from Example 1 only in that template molecules are not added, while the other steps are the same as in Example 1.

[0080] Comparative Example 2

[0081] This comparative example provides a method for preparing a non-imprinted polymer material, which differs from Example 1 only in that template molecules are not added, while the other steps are the same as in Example 2.

[0082] Comparative Example 3

[0083] This comparative example provides a method for preparing a non-imprinted polymer material, which differs from Example 1 only in that template molecules are not added, while the other steps are the same as in Example 3.

[0084] Comparative Example 4

[0085] This comparative example provides a method for preparing a non-imprinted polymer material, which differs from Example 1 only in that template molecules are not added, while the other steps are the same as in Example 4.

[0086] Comparative Example 5

[0087] This comparative example provides a method for preparing a non-imprinted polymer material, which differs from Example 1 only in that template molecules are not added, while the other steps are the same as in Example 5.

[0088] Comparative Example 6

[0089] This comparative example provides a method for preparing a non-imprinted polymer material, which differs from Example 1 only in that template molecules are not added, while the other steps are the same as in Example 6.

[0090] Comparative Example 7

[0091] This comparative example provides a method for preparing a non-imprinted polymer material, which differs from Example 1 only in that template molecules are not added, while the other steps are the same as in Example 7.

[0092] Comparative Example 8

[0093] This comparative example provides a method for preparing a non-imprinted polymer material, which differs from Example 1 only in that template molecules are not added, while the other steps are the same as in Example 8.

[0094] Test Example 1

[0095] The adsorption performance of the MIPS or NIPS materials obtained in Examples 1-8 and Comparative Examples 1-8 was tested. The specific experimental procedure was as follows: A 200 mg / L N-Boc-L-phenylalanine standard solution was prepared using methanol, acetonitrile, PBS buffer (pH=7), and water, respectively. 5 mg of the MIPS and NIPS materials prepared in Examples 1-8 and Comparative Examples 1-8 were weighed into 5 mL centrifuge tubes, and 1 mL of the prepared standard solution was added. After stirring and adsorption for 4 h, the N-Boc-L-phenylalanine content in the supernatant was determined by high-performance liquid chromatography (HPLC). The adsorption capacity and imprinting factor of the polymer material (MIPS or NIPS) for N-Boc-L-phenylalanine were calculated. Adsorption capacity (Q) e The formulas for calculating the imprint factor (IF) are as follows: Qe = m(C0 - Ce) × V IF=Q MIP / Q NIP

[0096] Q e(mg / g) represents the adsorption capacity of the polymer material (MIP or NIP); C0 (mg / L) and Ce (mg / L) are the initial and final concentrations of N-Boc-L-phenylalanine, respectively; m (g) is the mass of the polymer material (MIPS or NIPS); and V (mL) is the solvent volume. Results are as follows: Figure 1 As shown.

[0097] pass Figure 1 It was found that after comparing the adsorption performance of MIPs prepared with eight reaction solvents in four adsorption solvents, the adsorption capacity of MIPs was 5.88 mg / g and that of NIPs was 0.81 mg / g when acetonitrile was used as both the reaction and adsorption solvents, with the highest imprinting factor of 7.35. This indicates that the specific recognition effect was optimal under this combination. It is noteworthy that while some other solvent combinations also showed high adsorption capacities for MIPs, the adsorption capacities for NIPs were also relatively high, resulting in a small difference between the two and an imprinting factor close to 1. Through comprehensive comparison, only the combination of acetonitrile as both the reaction and adsorption solvents could maintain a high adsorption capacity while maximizing the difference between MIPs and NIPs, thus achieving the best imprinting effect.

[0098] The adsorption isotherm conforms to the Langmuir model (R 2 =0.9989), indicating uniform monolayer adsorption; the adsorption kinetics conform to the pseudo-second-order model (R² = 0.9989). 2 =0.9999), indicating that the rate-determining step of the adsorption process is chemisorption.

[0099] Test Example 2

[0100] This test case applies the MIP obtained in Example 1 to a real sample, as follows:

[0101] This test example analyzed the saturated adsorption capacity of Example 1 and Comparative Example 1. Standard solutions of N-Boc-L-phenylalanine with concentrations of 10 mg / L, 50 mg / L, 100 mg / L, 200 mg / L, 300 mg / L, 400 mg / L, 500 mg / L, 600 mg / L, 800 mg / L, and 1000 mg / L were prepared using acetonitrile as the solvent. 5 mg of the MIPS prepared in Example 1 and the NIPS prepared in Comparative Example 1 were weighed into 5 mL centrifuge tubes, and 1 mL of each of the above-mentioned standard solutions of different concentrations were added. The tubes were shaken and adsorbed at 25°C for 4 h. The N-Boc-L-phenylalanine content in the supernatant was determined by high-performance liquid chromatography (HPLC), and the adsorption capacity and imprinting factor of the polymer material (MIPS or NIPS) for N-Boc-L-phenylalanine were calculated. The results are as follows: Figure 2As shown.

[0102] Depend on Figure 2 It was observed that the adsorption capacity of MIP gradually increased with the increase of the initial concentration of N-Boc-L-phenylalanine, reaching saturation at an initial concentration of 600 mg / L, with an adsorption capacity of 14.50 mg / g. Thereafter, further increases in concentration did not significantly alter the adsorption capacity. The adsorption capacity of NIP remained consistently low (0.2–1.5 mg / g), indicating weak non-specific adsorption. The imprinting factor (IF) value reached its highest value (10.33) at 600 mg / L, indicating that the molecularly imprinted polymer exhibited the strongest specific recognition ability for the template molecule at this concentration. Therefore, the optimal initial adsorption concentration was determined to be 600 mg / L. Compared with existing Boc-L-phenylalanine molecularly imprinted polymers prepared by precipitation polymerization (e.g., as reported in the literature "Preparation of Boc-L-phenylalanine Imprinted Polymers by Precipitation Polymerization"), the technical solution of this invention, which combines bulk polymerization with allylamine functional monomers, has the following advantages: First, the imprinting factor is higher (10.33 vs. approximately 2-3), indicating that the specific recognition ability of the material of this invention is significantly enhanced; second, the initial concentration required to reach saturation adsorption is lower (600 mg / L vs. 8000 mg / L), indicating that the material of this invention has a stronger affinity for the template molecule; and third, the stability of the template-monomer pre-assembled complex is enhanced through the dual action of ionic bonds and hydrogen bonds.

[0103] Test Example 3

[0104] This test example demonstrates the chiral selective adsorption of the N-Boc-L-phenylalanine molecularly imprinted polymer material (MIPS) prepared in Example 1 and the non-imprinted polymer material (NIPS) prepared in Comparative Example 1.

[0105] The specific experimental procedure was as follows: Standard solutions of N-Boc-L-phenylalanine and N-Boc-D-phenylalanine with a concentration of 500 mg / L were prepared using acetonitrile as the solvent. 5 mg of the MIP prepared in Example 1 and the NIP prepared in Comparative Example 1 were weighed into 5 mL centrifuge tubes, and 1 mL of the above standard solutions were added to each. The tubes were shaken and adsorbed at 25 °C for 4 h. The equilibrium concentrations of N-Boc-L-phenylalanine and N-Boc-D-phenylalanine in the solutions after adsorption were determined by high-performance liquid chromatography (HPLC). The adsorption capacity and selectivity coefficients of the polymer materials for the two configurations were calculated. The results are shown in Table 1.

[0106] Table 1. Adsorption selectivity of Example 1 and Comparative Example 1 for L-type and D-type substrates

[0107] The results showed that the MIP prepared in Example 1 adsorbed 14.01 mg / g of N-Boc-L-phenylalanine and 8.37 mg / g of N-Boc-D-phenylalanine, with a selectivity coefficient α(L / D) of 1.67. The NIP prepared in Comparative Example 1 adsorbed 1.36 mg / g of N-Boc-L-phenylalanine and 2.13 mg / g of N-Boc-D-phenylalanine. These results indicate that the molecularly imprinted polymer material prepared in this invention preferentially recognizes N-Boc-L-phenylalanine and exhibits good chiral selectivity.

[0108] Test Example 4

[0109] This test example characterizes the MIP obtained in Example 1 using infrared spectroscopy, and the results are as follows: Figure 3 As shown.

[0110] Depend on Figure 3 It can be seen that FTIR characterization of N-Boc-L-Phe-MIPs after complete template elution showed that: 1725 cm⁻¹ -1 A strong ester carbonyl (C=O) stretching vibration peak appears at 1260 cm⁻¹. -1 1160 cm -1 The presence of a strong COC stretching vibration peak at 3350 cm⁻¹ proves that the crosslinking agent EGDMA has successfully polymerized to form a stable three-dimensional polymer backbone; -1 A broad NH stretching vibration peak appears at 1640 cm⁻¹. -1 1550 cm -1 A bending vibration peak of NH appears at 1050 cm⁻¹. -1 A CN stretching vibration peak was observed, confirming the successful bonding of the functional monomer allylamine to the polymer; the spectrum did not show the characteristic benzene ring peak of the template molecule N-Boc-L-phenylalanine (1510 cm⁻¹). -1 750 cm -1 The presence of characteristic peaks for the Boc group and carboxyl group indicates that the template molecule has been completely eluted, successfully constructing a structurally complete and site-defined specific recognition cavity. These results demonstrate that this invention successfully prepared an N-Boc-L-phenylalanine molecularly imprinted polymer that meets the design requirements.

[0111] Obviously, the specific implementation schemes described above are merely a further detailed explanation of the purpose, technical solution and beneficial effects of the present invention. It should be understood that the above descriptions are only specific examples of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a molecularly imprinted polymer that selectively adsorbs N-Boc-L-phenylalanine, characterized in that, Includes the following steps: S1: The template molecule N-Boc-L-phenylalanine is mixed with acetonitrile, and then the functional monomer allylamine is added to perform pre-assembly to obtain a prepolymer solution. S2: Add crosslinking agent and initiator to the prepolymerization solution, and carry out polymerization reaction under a protective atmosphere to obtain solid polymer; S3: The template molecules were removed by eluting the obtained solid polymer and then dried to obtain the N-Boc-L-phenylalanine molecularly imprinted polymer. The molar ratio of template molecule to functional monomer is 1:(1~8).

2. The preparation method according to claim 1, characterized in that, The molar ratio of template molecule: functional monomer: crosslinking agent is 1:(1~8):(10~50).

3. The preparation method according to claim 2, characterized in that, In step S2, the crosslinking agent is ethylene glycol dimethacrylate.

4. The preparation method according to claim 1, characterized in that, In step S2, the initiator is azobisisobutyronitrile, and the molar ratio of the initiator to the template molecule is 0.15~0.8:

1.

5. The preparation method according to claim 1, characterized in that, In step S2, the polymerization reaction temperature is 55~65℃ and the reaction time is 12~28h.

6. The preparation method according to claim 1, characterized in that, The protective atmosphere described in step S2 is nitrogen or argon, and the polymerization process is carried out under stirring at a speed of 200 rpm.

7. The preparation method according to claim 1, characterized in that, In step S3, a template removal agent is used for elution. The template removal agent is a mixture of methanol and 0.1% sodium hydroxide aqueous solution.

8. The preparation method according to claim 1, characterized in that, After drying in step S3, grind the product through a 100-500 mesh sieve; the drying temperature is 60-100℃ and the drying time is 6-24 hours.

9. An N-Boc-L-phenylalanine molecularly imprinted polymer, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the N-Boc-L-phenylalanine molecularly imprinted polymer according to claim 9, characterized in that, The molecularly imprinted polymer is used for the selective recognition, chiral separation, adsorption, and enrichment of N-Boc-L-phenylalanine.

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