Multifunctional silica support, process for its preparation and use

Abstract

The present application relates to a kind of multifunctional silica carrier and its preparation method and application, belong to inorganic material technical field.The preparation method of the present application includes the following steps: S1, polystyrene-divinylbenzene microspheres are dispersed in first solvent, after adjusting pH to 9.5-10, dropwise addition tetraethyl orthosilicate solution is reacted, after washing, drying, calcination, obtain porous silica microspheres;S2, porous silica microspheres are dispersed in second solvent, after reflux pretreatment, add silane coupling agent and reflux reaction, after centrifugation, washing, drying, obtain aminated porous silica microspheres;S3, Fmoc linker, condensing agent, condensing adjuvant and aminated porous silica microspheres are stirred in third solvent, after washing, using acetic anhydride-diisopropylethylamine mixed system is acetylated and capped, obtain multifunctional silica carrier.

Description

Technical Field

[0001] This invention belongs to the field of inorganic materials technology, and particularly relates to a multifunctional silica carrier, its preparation method and application. Background Technology

[0002] Peptides, with their excellent bioactivity and biocompatibility, possess immense application value in numerous fields such as biomedicine, biomaterials, and clinical diagnostic reagents. With the rapid expansion and technological iteration of the global peptide drug industry, solid-phase peptide synthesis technology has become a core supporting technology for the industrial-scale production of peptides. As a core component of this technology, the solid support not only undertakes the fundamental function of immobilizing the first amino acid molecule but also plays a decisive role in the diffusion rate of reactants, the efficiency of amino acid coupling reactions, and the purity and yield of the final peptide product. Therefore, the structural characteristics and physicochemical properties of the solid support directly determine the overall process level and product quality of solid-phase peptide synthesis.

[0003] Currently, the mainstream solid-phase peptide synthesis carriers in the industrial field are mainly divided into two types: cross-linked polystyrene matrix resins and polyethylene glycol hydrophilic resins. Among them, cross-linked polystyrene resins, represented by Merrifield resin, have the advantages of excellent mechanical strength and high functional group substitution degree. However, the matrix of this type of carrier is highly hydrophobic and has poor swelling performance in polar reaction solvents, which will significantly limit the penetration and diffusion of reagents inside the resin, thereby reducing the coupling reaction efficiency of peptide chains. Polyethylene glycol hydrophilic resins, represented by PEG-based resins and PEG-PS copolymer resins, have good hydrophilicity and solvent compatibility, which can effectively improve the diffusion effect of reagents. However, they generally have the disadvantage of weak mechanical strength. In large-scale industrial stirring reactions and production scale-up processes, problems such as carrier compression and breakage are prone to occur, resulting in a short service life and difficulty in adapting to the needs of continuous industrial production.

[0004] At the same time, existing traditional peptide synthesis resin carriers generally have pore structure defects, mostly small pore structure or non-porous structure, with pore size concentrated in the range of tens to hundreds of angstroms. When synthesizing long-chain peptides or amino acid derivatives with large steric hindrance, they will severely restrict the diffusion rate of reactants, and are very likely to cause side reactions such as incomplete coupling reaction and sequence deletion, generating a large number of impurity by-products, which will significantly reduce the purity of peptide products and the success rate of synthesis.

[0005] In summary, existing peptide synthesis carriers generally suffer from numerous technical defects, such as poor solvent suitability, unreasonable pore structure design, insufficient mechanical stability, and uneven distribution of structure and functional groups. They are unable to simultaneously achieve excellent hydrophilicity, high mechanical stability, and a macroporous structure suitable for long peptide synthesis, which seriously restricts the improvement of peptide synthesis efficiency and the upgrading of product quality.

[0006] Therefore, developing a multifunctional peptide synthesis carrier that combines high mechanical stability, excellent hydrophilicity, and macroporous structure is of great practical significance and application value for promoting the high-quality development of the peptide synthesis industry. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a multifunctional silica carrier, its preparation method, and its application.

[0008] The first objective of this invention is to provide a method for preparing a multifunctional silica carrier, comprising the following steps: S1. Polystyrene-divinylbenzene microspheres were dispersed in a first solvent, and after adjusting the pH to 9.5-10, tetraethyl orthosilicate solution was added dropwise to carry out the reaction. After washing, drying and calcination, porous silica microspheres were obtained. S2. The porous silica microspheres described in S1 are dispersed in a second solvent, and after reflux pretreatment, a silane coupling agent is added for reflux reaction. After centrifugation, washing, and drying, aminated porous silica microspheres are obtained. S3, Fmoc linker, condensing agent, condensing aid, and the aminated porous silica microspheres described in S2 are stirred and reacted in a third solvent. After washing, the microspheres are acetylated and capped using an acetic anhydride-diisopropylethylamine mixture. After washing and drying, the multifunctional silica carrier is obtained.

[0009] In one embodiment of the present invention, in S1, the average particle size of the polystyrene-divinylbenzene microspheres is 65 μm-75 μm and the average pore size is 1450 Å-1550 Å. And / or, the mass fraction of the tetraethyl orthosilicate solution is 8%-10%; And / or, the mass-to-volume ratio of the polystyrene-divinylbenzene microspheres to the tetraethyl orthosilicate solution is 5 g: (148-152) mL.

[0010] In one embodiment of the present invention, in S1, the dripping rate is 0.1 mL / min - 0.2 mL / min; And / or, the reaction is carried out at a temperature of 25°C-30°C for a time of 24-30 hours; And / or, the drying temperature is 50℃-60℃, and the time is 24h-30h; And / or, the calcination is carried out by heating to 550℃-600℃ at a rate of 5℃ / min-10℃ / min and holding at that temperature for 10h-12h.

[0011] In one embodiment of the present invention, in S2, the silane coupling agent is selected from (3-aminopropyl)triethoxysilane and / or (3-aminopropyl)trimethoxysilane; And / or, the mass-to-volume ratio of the porous silica microspheres to the aminosilane reagent is 0.5 g: (0.8-1) mL.

[0012] In one embodiment of the present invention, in S2, the temperature of the reflux pretreatment is 100℃-110℃ and the time is 28min-32min; And / or, the reflux reaction is carried out at a temperature of 100℃-110℃ for a time of 24h-30h.

[0013] In one embodiment of the present invention, in S3, the condensing agent is selected from diisopropylcarbodiimide and / or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride; And / or, the condensation aid is selected from 1-hydroxybenzotriazole and / or 1-hydroxy-7-azobenzotriazole; And / or, based on the amino equivalent content of the aminated porous silica microspheres, the equivalent ratio of Fmoc linker, condensing agent, condensing aid to aminated porous silica microspheres is 3:(3.8-4.2):(5.8-6.2).

[0014] In one embodiment of the present invention, in S3, the stirring speed is 30 rpm-40 rpm and the time is 3 h-4 h.

[0015] In one embodiment of the present invention, in S3, the molar ratio of acetic anhydride to diisopropylethylamine in the acetic anhydride-diisopropylethylamine mixed system is 1:(1.8-2.2). And / or, the equivalent ratio of the Fmoc linker and the acetic anhydride-diisopropylethylamine mixture is 3:(9-11).

[0016] A second objective of this invention is to provide a multifunctional silica carrier prepared by the method described above.

[0017] A third objective of this invention is to provide an application of the aforementioned multifunctional silica support in solid-phase synthesis of polypeptides.

[0018] The technical solution of the present invention has the following advantages compared with the prior art: (1) The preparation method of the present invention uses polystyrene-divinylbenzene microspheres as hard templates, selects tetraethyl orthosilicate as silicon source, constructs a weakly alkaline reaction system with the help of ammonia water, and prepares porous silica microspheres by relying on alkaline catalytic sol-gel reaction. In the system, tetraethyl orthosilicate first undergoes hydrolysis reaction, and the ethoxy groups in the molecule are gradually replaced by hydroxyl groups to generate highly reactive silanol intermediates. The silanols further carry out dehydration and de-alcoholization condensation reactions with each other and with incompletely hydrolyzed silicate esters, gradually constructing a continuous Si-O-Si three-dimensional network structure. At the same time, the operation mode of low-speed dropwise addition of silicon source solution can balance and control the hydrolysis and condensation reaction process, avoid the problem of pore blockage caused by local rapid gelation, and with constant temperature and long-term reaction, the silanols can be fully The polystyrene-divinylbenzene template with regular particle size and interconnected channels penetrates into the interior of the microspheres, uniformly depositing and completing polycondensation on the inner wall of the channels. This completely replicates the internal pore structure of the template, preventing the formation of a thin coating layer only on the surface of the microspheres. After the reaction, the product is washed with solvent, dried at low temperature, and then calcined at a programmed temperature. During the calcination process, the organic polystyrene-divinylbenzene template is completely decomposed and removed by heat, while the thermally stable Si-O-Si inorganic three-dimensional network structure is preserved. Finally, porous silica microspheres with an interconnected macroporous structure that maintain a complete spherical appearance are obtained. This macroporous structure can meet the diffusion and transport requirements of biomacromolecules during peptide synthesis and is also suitable for subsequent functionalization modification processes such as silane amination modification and Fmoc linker grafting.

[0019] (2) The preparation method of the present invention uses an amino-based silane coupling agent to perform surface amination modification on porous silica microspheres in a reflux system. The reflux heating pretreatment can fully activate the silanol groups on the surface of silica microspheres. The alkoxy groups in the silane coupling agent molecules first undergo hydrolysis to generate highly active silanol intermediates. On the one hand, the silanol intermediates undergo dehydration condensation reaction with the large amount of Si-OH present on the inner and outer surfaces of silica channels to generate stable Si-O-Si covalent bonds, firmly grafting the aminopropyl segments onto the carrier surface. On the other hand, a small amount of silane coupling agent molecules will simultaneously undergo condensation polymerization to form siloxane cross-linked substructures. Because the number of active silanol groups on the silica surface is sufficient, the covalent grafting reaction between the silane coupling agent and the carrier surface always dominates. After modification, a large number of primary amino groups can be uniformly introduced into the entire pores of the porous silica microspheres, providing uniformly distributed and stably bound active reaction sites for subsequent Fmoc linker condensation coupling.

[0020] (3) The preparation method of the present invention uses a condensation system composed of a condensing agent and a condensation aid to covalently bond the Fmoc linker to the surface of the aminated porous silica microspheres. During the reaction, the carboxyl group carried by the Fmoc linker is first activated by the condensing agent to generate a highly active intermediate. This intermediate is unstable and easily triggers side reactions. After adding the condensation aid to the system, an activated ester with stronger stability and higher reactivity can be further generated, which not only improves the coupling efficiency between the amino group and the Fmoc linker, but also inhibits the generation of various side reactions. Subsequently, the amino groups uniformly distributed inside and outside the pores of the porous silica microspheres act as nucleophiles to attack the carbonyl carbon of the activated ester. After transformation by the tetrahedral intermediate and removal of the condensation aid, the carbonyl carbon is removed. An amide bond with excellent chemical stability is formed to achieve a strong covalent bond between the Fmoc linker and the inorganic carrier. This amide bond can withstand multiple acid and base treatments such as deprotection of Fmoc and amino acid coupling throughout the solid-phase peptide synthesis process. After the coupling reaction is completed, an acetylation end-capping treatment is carried out using an acetic anhydride-diisopropylethylamine mixed system to convert the residual primary amino groups on the carrier surface that did not participate in the coupling reaction into a stable acetamide structure, completely eliminating free active amino sites, optimizing the uniformity of functional group distribution on the carrier surface, avoiding side reactions such as sequence deletion induced by residual amino groups during peptide synthesis, reducing the generation of impurities in the peptide, and simultaneously improving the purity of the crude peptide and the overall synthesis yield. Attached Figure Description

[0021] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is the RP-HPLC chromatogram of the nonapeptide synthesized using the multifunctional silica support in Example 1 of this invention. Figure 2 This is the RP-HPLC chromatogram of the nonapeptide synthesized using the multifunctional silica support in Example 2 of this invention. Figure 3 This is the RP-HPLC chromatogram of the synthesis of nonapeptide using the multifunctional polystyrene-divinylbenzene carrier in Comparative Example 1 of this invention. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.

[0023] In this invention, unless otherwise stated, the technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] In this invention, unless otherwise stated, the term "and / or" as used includes any and all combinations of one or more of the associated listed items.

[0025] In this invention, unless otherwise specified, the experimental methods used are conventional methods, and the materials and reagents used are commercially available unless otherwise specified. Example 1

[0026] The multifunctional silica carrier and its preparation method in this embodiment specifically include the following steps: S1. Preparation of porous silica microspheres: 5.0 g of polystyrene-divinylbenzene microspheres with an average particle size of about 70 μm and an average pore size of about 1500 Å were dispersed in a mixed solvent of 200 mL isopropanol and 50 mL ultrapure water. After ultrasonic treatment for 10 min, ammonia was added to adjust the pH of the system to 10. 150 mL of a 10% tetraethyl orthosilicate isopropanol solution was slowly added dropwise at a rate of 0.2 mL / min using a peristaltic pump. The reaction was carried out under continuous stirring at 30 °C for 24 h. After the reaction, the product was washed with ethanol and ultrapure water in sequence. The obtained solid was first dried at 60 °C for 24 h, and then calcined at 600 °C for 10 h at a rate of 10 °C / min to obtain porous silica microspheres with a particle size of about 60 μm and a pore size of about 1200 Å-1300 Å. S2. Preparation of Aminated Porous Silica Microspheres: 0.5 g of porous silica microspheres were dispersed in 50 mL of toluene and refluxed under magnetic stirring at 110 °C. After 30 min of reflux, 1 mL of (3-aminopropyl)triethoxysilane was added, and the mixture was stirred and reacted at the same temperature for 24 h. After the reaction was completed, the mixture was centrifuged, washed with 80% ethanol aqueous solution, and then dried in an oven at 60 °C to obtain aminated porous silica microspheres with an amino loading of 0.69 mmol / g. S3. Preparation of multifunctional silica support: 3 equivalents (based on amino equivalents) of Fmoc-linker, 4 equivalents of diisopropylcarbodiimide (DIC), and 6 equivalents of 1-hydroxybenzotriazole (HOBt) were dissolved in N,N-dimethylformamide (DMF). 1 g of aminated porous silica microspheres were added, and the mixture was placed on a blood rotator at 40 rpm and stirred at room temperature for 3 h. After the reaction was completed, the microspheres were washed with DMF (3 × 5 mL), and then acetylated and capped in a 1:2 molar ratio system of acetic anhydride (Ac2O)-diisopropylethylamine (DIEA) for 30 min to eliminate unreacted residual amino groups in the system. After capping, the microspheres were washed sequentially with DMF (3 × 5 mL) and dichloromethane (DCM) (3 × 5 mL). After drying, a multifunctional silica support with an actual bonding loading of 0.45 mmol / g was obtained. Example 2

[0027] The multifunctional silica carrier and its preparation method in this embodiment specifically include the following steps: S1. Preparation of porous silica microspheres: 5.0 g of polystyrene-divinylbenzene microspheres with an average particle size of about 70 μm and an average pore size of about 1500 Å were dispersed in a mixed solvent of 200 mL isopropanol and 50 mL ultrapure water. After ultrasonic treatment for 10 min, ammonia was added to adjust the pH of the system to 9.5. 150 mL of 8% tetraethyl orthosilicate isopropanol solution was slowly added dropwise at a rate of 0.1 mL / min using a peristaltic pump. The reaction was continuously stirred at 25 °C for 30 h. After the reaction, the product was washed with ethanol and ultrapure water in sequence. The obtained solid was first dried at 50 °C for 30 h, and then calcined at 550 °C for 12 h at a rate of 5 °C / min to obtain porous silica microspheres with a particle size of about 62 μm and a pore size of about 1100 Å-1200 Å. S2. Preparation of aminated porous silica microspheres: 0.5 g of porous silica microspheres were dispersed in 50 mL of xylene and refluxed under magnetic stirring at 100 °C. After 30 min of incubation, 0.8 mL of (3-aminopropyl)trimethoxysilane was added, and the reaction was continued at the same temperature with stirring for 30 h. After the reaction was completed, the microspheres were centrifuged, washed with 75% ethanol aqueous solution, and then dried in an oven at 50 °C to obtain aminated porous silica microspheres with an amino loading of 0.52 mmol / g. S3. Preparation of multifunctional silica support: 3 equivalents (based on amino equivalents) of Fmoc-linker, 4 equivalents of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI), and 6 equivalents of 1-hydroxy-7-azobenzotriazole (HOAt) were dissolved in N-methylpyrrolidone (NMP). 1 g of aminated porous silica microspheres were added, and the mixture was stirred at room temperature for 4 h on a blood rotator at 30 rpm. After the reaction was completed, the microspheres were washed with DMF (3 × 5 mL), and then acetylated and capped for 30 min in a 1:2 molar ratio system of acetic anhydride (Ac2O)-diisopropylethylamine (DIEA) to eliminate unreacted residual amino groups in the system. After capping, the microspheres were washed sequentially with DMF (3 × 5 mL) and dichloromethane (DCM) (3 × 5 mL). After drying, a multifunctional silica support with an actual bonding loading of 0.32 mmol / g was obtained. Comparative Example 1

[0028] Basically the same as Example 1, except that: aminated porous silica microspheres are replaced with aminated polystyrene-divinylbenzene microspheres, and their preparation specifically includes the following steps: S1. Preparation of polystyrene-divinylbenzene microspheres: Add 2.0 g of polyvinyl alcohol (PVA) to 200 mL of deionized water, stir and heat to 60 °C until the solid is completely dissolved, then cool to room temperature to prepare an aqueous solution; weigh 46.2 g of styrene and 0.72 g of divinylbenzene, mix thoroughly, add 0.47 g of benzoyl peroxide (BPO), stir thoroughly to dissolve and prepare an oil solution; at room temperature, mechanically stir at 350 rpm, then quickly pour the oil solution into the aqueous solution, relying on shear force to separate... The mixture was dispersed into uniform oil phase droplets, and nitrogen gas was introduced to purge the system for 15 minutes to remove oxygen. The temperature was raised to 75℃ and kept constant for 2 hours, then raised to 85℃ and kept constant for 4 hours. After the reaction was completed, the mixture was cooled to room temperature. The filtered cake was first washed repeatedly with 70℃ hot water and deionized water, and then washed successively with anhydrous ethanol, acetone and dichloromethane. The obtained solid was dried in a vacuum environment at 50℃ to constant weight. After classification and sieving, polystyrene-divinylbenzene microspheres with a particle size of 75μm-150μm and a crosslinking degree of 1% were obtained. S2. Preparation of Aminated Polystyrene-Divinylbenzene Microspheres: 5.0 g of polystyrene-divinylbenzene microspheres were added to a reactor and 80 mL of dichloromethane was added to swell the microspheres for 30 min. Then, 2.2 g of N-(hydroxymethyl)phthalimide and 1.0 g of methanesulfonic acid were added to the system. The mixture was stirred at 25 °C for 5 h. After the reaction was completed, the microspheres were filtered, and the solid was washed with dichloromethane and methanol and dried. The dried solid was dispersed in anhydrous ethanol, and 40 mL of 20% (v / v) 2-aminoethanol solution was added. The mixture was stirred and heated to reflux and kept at that temperature for 7 h. After the reaction was completed, the solid was cooled to room temperature and filtered. The obtained solid was washed with anhydrous ethanol, N,N-dimethylformamide, and dichloromethane and dried to obtain aminated polystyrene-divinylbenzene microspheres with an amino loading of 0.94 mmol / g. Test Example 1

[0029] 100 mg of the multifunctional silica carriers from Examples 1 and 2, and the multifunctional polystyrene-divinylbenzene carrier prepared in Comparative Example 1 were weighed out respectively. The nonapeptide model H-Met-Pro-Asp-Val-Ala-Glu-Val-Pro-Val-NH2 (MPDVAEVPV) was assembled using the Fmoc / tBu solid-phase peptide synthesis strategy. During the synthesis, the Fmoc-AA-OH / DIC / HOBt condensation system was used, with a molar ratio of 1:1:1 and a feed equivalent of 3 equivalents. Fmoc protection was removed twice using a 20% piperidine DMF solution. The base was removed in 5-minute cycles. Different parameters were set for the washing process: the multifunctional silica carrier was washed three times with 5 times its volume of DMF solution per step, while the multifunctional polystyrene-divinylbenzene carrier was washed three times with 12 times its volume of DMF solution. After polypeptide chain assembly, lysis was performed at room temperature for 2 hours using a 95:2.5:2.5 TFA-TIS-H2O lysis buffer. The nonapeptide was obtained after cold ether precipitation and centrifugation. The purity and impurity distribution of the nonapeptide were finally characterized using RP-HPLC with a detection wavelength of 215 nm and a 5%-95% acetonitrile gradient elution. Figures 1-3 As shown in Table 1: Table 1

[0030] from Figures 1-3As shown in Table 1, different supports have significant effects on the purity of the synthesized nonapeptide and the amount of impurities generated. The nonapeptide sample synthesized by the multifunctional silica support in the examples is generally better than the multifunctional polystyrene-divinylbenzene support in Comparative Example 1. Among them, the nonapeptide sample synthesized by the multifunctional silica carrier in Example 1 had a main peak purity of 84.03% and a product recovery rate of 82.5%, which was the best among the three groups of samples. Combined with the chromatographic data, it can be seen that its target product main peak area ratio was the highest and the peak height was prominent. The number of impurity peaks in the spectrum was small and the area of ​​each impurity peak was at a low level. Only a trace amount of peptide sequence deletion impurities were generated, and the inhibitory ability of coupling side reactions was the strongest. The nonapeptide sample synthesized by the multifunctional silica carrier in Example 2 had a main peak purity of 75.46% and a recovery rate of 78.6%, both of which were higher than those of Comparative Example 1. Although the number of impurity peaks and the total peak area in the chromatography were slightly more than those in Example 1, the overall proportion of various by-products was significantly lower. The nonapeptide sample synthesized by the multifunctional polystyrene-divinylbenzene carrier in Comparative Example 1 had a main peak purity of only 74.93% and a product recovery rate of 76.4%, both of which were the lowest among the three groups. Multiple medium-area impurity peaks appeared in the corresponding chromatography, and the proportion of peptide sequence deletion by-products increased significantly. The macroporous silica carrier of the embodiment demonstrates that its macroporous structure and hydrophilic surface can enhance the penetration and mass transfer efficiency of the reaction reagents inside the carrier pores, effectively reducing side reactions such as incomplete coupling and sequence deletion during long-chain peptide synthesis, and simultaneously improving the purity of the crude peptide main peak and the product recovery efficiency. In contrast, the traditional polystyrene resin matrix is ​​highly hydrophobic and has a small pore size, resulting in poor swelling effect and high internal mass transfer resistance in peptide synthesis solvents. It is also prone to generating a large number of impurities with missing sequences, ultimately causing a simultaneous decrease in the purity of the target peptide crude product and the product yield.

[0031] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing a multifunctional silica carrier, characterized in that, Includes the following steps: S1. Polystyrene-divinylbenzene microspheres were dispersed in a first solvent, and after adjusting the pH to 9.5-10, tetraethyl orthosilicate solution was added dropwise to carry out the reaction. After washing, drying and calcination, porous silica microspheres were obtained. S2. The porous silica microspheres described in S1 are dispersed in a second solvent, and after reflux pretreatment, a silane coupling agent is added for reflux reaction. After centrifugation, washing, and drying, aminated porous silica microspheres are obtained. S3, Fmoc linker, condensing agent, condensing aid, and the aminated porous silica microspheres described in S2 are stirred and reacted in a third solvent. After washing, the microspheres are acetylated and capped using an acetic anhydride-diisopropylethylamine mixture. After washing and drying, the multifunctional silica carrier is obtained.

2. The method for preparing the multifunctional silica carrier according to claim 1, characterized in that, In S1, the average particle size of the polystyrene-divinylbenzene microspheres is 65 μm-75 μm, and the average pore size is 1450 Å-1550 Å. And / or, the mass fraction of the tetraethyl orthosilicate solution is 8%-10%; And / or, the mass-to-volume ratio of the polystyrene-divinylbenzene microspheres to the tetraethyl orthosilicate solution is 5 g: (148-152) mL.

3. The method for preparing the multifunctional silica carrier according to claim 1, characterized in that, In S1, the dropping rate is 0.1 mL / min - 0.2 mL / min; And / or, the reaction is carried out at a temperature of 25°C-30°C for a time of 24-30 hours; And / or, the drying temperature is 50℃-60℃, and the time is 24h-30h; And / or, the calcination is carried out by heating to 550℃-600℃ at a rate of 5℃ / min-10℃ / min and holding at that temperature for 10h-12h.

4. The method for preparing the multifunctional silica carrier according to claim 1, characterized in that, In S2, the silane coupling agent is selected from (3-aminopropyl)triethoxysilane and / or (3-aminopropyl)trimethoxysilane; And / or, the mass-to-volume ratio of the porous silica microspheres to the aminosilane reagent is 0.5 g: (0.8-1) mL.

5. The method for preparing the multifunctional silica carrier according to claim 1, characterized in that, In S2, the reflux pretreatment temperature is 100℃-110℃ and the time is 28min-32min; And / or, the reflux reaction is carried out at a temperature of 100℃-110℃ for a time of 24h-30h.

6. The method for preparing the multifunctional silica carrier according to claim 1, characterized in that, In S3, the condensing agent is selected from diisopropylcarbodiimide and / or 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride; And / or, the condensation aid is selected from 1-hydroxybenzotriazole and / or 1-hydroxy-7-azobenzotriazole; And / or, based on the amino equivalent content of the aminated porous silica microspheres, the equivalent ratio of Fmoc linker, condensing agent, condensing aid to aminated porous silica microspheres is 3:(3.8-4.2):(5.8-6.2).

7. The method for preparing the multifunctional silica carrier according to claim 1, characterized in that, In S3, the stirring speed is 30 rpm-40 rpm and the time is 3 h-4 h.

8. The method for preparing the multifunctional silica carrier according to claim 1, characterized in that, In S3, the molar ratio of acetic anhydride to diisopropylethylamine in the acetic anhydride-diisopropylethylamine mixed system is 1:(1.8-2.2). And / or, the equivalent ratio of the Fmoc linker and the acetic anhydride-diisopropylethylamine mixture is 3:(9-11).

9. The multifunctional silica carrier prepared by the method of any one of claims 1-8.

10. The application of the multifunctional silica support as described in claim 9 in solid-phase synthesis of peptides.

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