Small molecule boron-10 carrying agent, preparation method and application

Abstract

The invention relates to a small molecular boron-10 carrying agent, a preparation method and application. The structural formula of the small molecule boron-10 carrying agent is shown as a formula (I). The invention also provides a preparation method of the small molecular boron-10 carrying agent, which comprises the following steps: carrying out condensation connection on a phenylboronic acid derivative and N-(2-aminoethyl) maleimide hydrochloride, and covalently coupling a boron drug to obtain a first intermediate; n < 2 >-(((9H-fluorene-9-yl) methoxy) carbonyl)-N < 6 >-(tert-butoxycarbonyl)-L-lysine, N-(2-aminoethyl) maleimide hydrochloride and a phenylboronic acid derivative are subjected to condensation connection, and a second intermediate is obtained; carrying out esterification connection on a selenium-containing compound and a DNA repair inhibiting compound to obtain a third intermediate; and carrying out condensation connection on the second intermediate and the third intermediate, and connecting the first intermediate to obtain the small molecule boron-10 carrying agent. The invention solves the problems of limited treatment effect and difficulty in inhibiting DNA damage repair in the existing BNCT. # imgabs0 # (I)

Description

Technical Field

[0001] The present invention relates to the technical field of medical drugs, and in particular to a small molecule boron-10 carrier, a preparation method and application thereof. Background Art

[0002] With the continuous increase in the incidence of malignant tumors and their high mortality rate worldwide, the treatment of malignant tumors has become a major challenge facing the field of human health. Currently, chemotherapy, radiotherapy and surgery are the main means of treating malignant tumors. However, compared with traditional radiotherapy, boron neutron capture therapy (BNCT) has demonstrated its unique advantages, such as high selectivity, local high-efficiency lethality, and suitability for the treatment of complex parts, thus helping to solve the problem of tumor targeted radiotherapy. As an emerging binary tumor-targeted radiotherapy mode, the key to the success of BNCT lies in the use of boron carriers and thermal (epithermal) neutron beams. BNCT has shown good therapeutic potential for primary or recurrent malignant tumors that are resistant to conventional therapies. BNCT uses biocompatible boron delivery agents to deliver boron-10 ( 10 B) atoms selectively gather into cancer cells; then the tumor tissue is irradiated with thermal neutrons, which triggers the neutrons to interact with the tumor cells. 10 B occurs 10 B (n,α)7Li nuclear reaction, 10 B captures thermal neutrons to form a composite nucleus 11 B, 11 B rapidly splits into alpha particles (4He) and lithium-7 (7Li) atoms, generating 2.4 MeV of energy. 10 B-atom compounds selectively accumulate in cancer cells, so this radiotherapy can selectively damage tumor cells while having little effect on surrounding healthy cells. BNCT greatly reduces the side effects associated with traditional cancer treatments such as chemotherapy and radiotherapy.

[0003] However, BNCT therapy still faces many difficulties and challenges in practical application. First, it is necessary to develop more tumor-selective and effective BNCTs that can deliver effective BNCTs to tumor tissues. 10B dose (~20μg / g) of boron delivery agent. Secondly, such boron-containing drugs must remain in the tumor tissue for a long enough time and be cleared from the surrounding normal tissues to achieve the ideal effect of a boron drug ratio of greater than 3:1 in the tumor to normal tissue. Although the DNA damage caused by BNCT is very serious, some tumor cells may still repair the damaged DNA chains through their own DNA repair mechanisms. These repair mechanisms include pathways such as non-homologous end joining (NHEJ) and homologous recombination repair (HRR). Possible reasons include: (1) Tumor cells have a complex DNA repair system that can sense and repair DNA damage. The role of these repair mechanisms is to maintain the stability of the genome; (2) The high-energy particles generated by BNCT usually cause severe DNA double-strand breaks, but not all breaks are fatal. Some breaks may be easier to repair or only cause partial DNA damage. Such damage may not immediately lead to cell death, and cells may survive with the help of DNA repair mechanisms; (3) Tumor cells often have higher genomic instability and adaptability. Especially in the face of treatment-induced DNA damage, tumor cells have better repair and survival capabilities than normal cells. Therefore, it is urgent to combine BNCT with chemotherapy or other therapies for BNCT treatment of malignant tumors. 10 BPA boron medicine is approved by FDA for marketing. 10 BPA boron drugs have the disadvantages of poor tumor selectivity, poor water solubility, short blood half-life, low drug enrichment in tumor tissues, and short retention time. In addition, a large amount of excipients such as fructose are used during the treatment process. The infusion of high-dose fructose in the body can easily lead to insulin resistance in diabetic patients and increased uric acid levels in patients with hyperuricemia and gout, which brings serious health risks to some tumor patients, which seriously limits the therapeutic effect of BNCT. Therefore, the development of a new water-soluble small molecule boron-10 carrier that can not only significantly improve the therapeutic effect of BNCT, but also inhibit DNA damage repair and reduce related biological toxicity has become an urgent need in the field of BNCT treatment of malignant tumors. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a small molecule boron-10 carrier, a preparation method and an application, so as to solve the problems of limited therapeutic effect and difficulty in inhibiting DNA damage repair in existing BNCT, and to provide a new boron drug option for enhancing the efficacy of BNCT.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A small molecule boron-10 carrier, the structural formula of which is a compound represented by formula (I) and its racemate, stereoisomer, tautomer or pharmaceutically acceptable salt; (I) In formula (I), C is selected from ; L is selected from .

[0006] The small molecule boron-10 carrier of the above structure can target tumor cells. Phenylboronic acid derivatives can react with sialic acid highly expressed on the surface of tumor cells. Glycolysis is the main metabolic mode of tumor cell metabolism. Tumor cells tend to obtain energy through glycolysis in aerobic or anaerobic conditions, and glycolysis mainly decomposes glucose. Compared with normal cells, tumor cells have more vigorous metabolism, so the uptake of glucose is more significant; phenylboronic acid will form a boric acid ester bond with glucose to prolong the tumor retention time and increase the concentration of tumor boron drug enrichment, thereby enhancing the selective accumulation of drugs.

[0007] Preferably, the small molecule boron-10 carrier is made of boron drugs and at least one of phenylboronic acid derivatives, selenium-containing compounds and DNA repair inhibitory compounds.

[0008] Preferably, the phenylboronic acid derivative is selected from at least one of 4-carboxy-3-fluorophenylboronic acid, 4-carboxy-phenylboronic acid and 5-fluoro-dimethyl-phenylboronic acid.

[0009] Among them, the structural formula of 4-carboxyl-3-fluorophenylboronic acid is .

[0010] The structural formula of 4-carboxyl-phenylboronic acid is .

[0011] The structural formula of 5-fluoro-dimethyl-phenylboronic acid is .

[0012] Preferably, the phenylboronic acid derivative is selected from 4-carboxy-3-fluorophenylboronic acid.

[0013] Preferably, the boron drug is selected from disodium mercapto dodecaborane ( 10 BSH) and L-borylphenylalanine ( 10 BPA) or both.

[0014] Preferably, the selenium-containing compound is selected from at least one of L-selenocysteine, seleno-DL-cystine and selenocystamine.

[0015] The diselenide bonds in selenium-containing compounds are very sensitive to ionizing radiation and can easily break and oxidize to form selenic acid, inducing cancer cells to produce ROS and leading to cell apoptosis.

[0016] Among them, the structural formula of L-selenocysteine ​​is .

[0017] The structural formula of seleno-DL-cystine is .

[0018] The structural formula of selenocystamine is .

[0019] Preferably, the diselenide compound is selected from selenocystamine.

[0020] Among them, nitroimidazole compounds have electrophilic properties. Under the activation of bioreductase in the hypoxic environment of tumors, their electrophilicity becomes stronger and they can directly combine with nucleophilic biological macromolecule free radicals (such as nucleic acids, proteins, etc.) generated by radiation, making it impossible for tumor cells to complete self-repair and thus accelerating their death.

[0021] Preferably, the nitroimidazole compound is at least one selected from metronidazole, ornidazole and 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid.

[0022] Among them, the structural formula of metronidazole is .

[0023] The structural formula of ornidazole is .

[0024] The structural formula of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid is .

[0025] Preferably, the nitroimidazole compound is selected from 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid.

[0026] The present invention also provides a method for preparing a small molecule boron-10 carrier, comprising the following steps: The phenylboronic acid derivative and N-(2-aminoethyl)maleimide hydrochloride are connected through acid-amine condensation, and then the boron drug is covalently coupled through an addition reaction, and then purified to obtain a molecular boron-10 carrier.

[0027] The present invention also provides a method for preparing a small molecule boron-10 carrier, comprising the following steps: Connecting N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine, N-(2-aminoethyl)maleimide hydrochloride and phenylboronic acid derivatives through acid-amine condensation, rotary evaporation and purification to obtain a first intermediate; The selenium-containing compound and the DNA repair inhibiting compound are connected by esterification reaction, and purified to obtain a second intermediate; The first intermediate and the second intermediate are connected through an acid-amine condensation reaction, and then connected to a boron drug through an addition reaction to obtain a small molecule boron-10 carrier.

[0028] Preferably, the preparation method of the small molecule boron-10 carrier comprises the following steps: connecting 4-carboxy-3-fluorophenylboric acid and N-(2-aminoethyl)maleimide hydrochloride by acid-amine condensation, and then covalently coupling by Michael addition reaction. 10 BSH was evaporated and purified by HPLC to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL- 10 BSH (4F-PBA-MAL- 10 BSH).

[0029] Preferably, the preparation method of the small molecule boron-10 carrier comprises the following steps: connecting N2-(((9H-fluoren-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine and N-(2-aminoethyl)maleimide hydrochloride and 4-carboxy-3-fluorophenylboronic acid through acid-amine condensation, rotary evaporation, and HPLC purification to obtain 4F-phenylboronic acid-Linker-maleimide; Selenocysteine ​​and 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid are connected by esterification reaction, and then subjected to rotary evaporation and HPLC purification to obtain selenocysteine-nitroimidazole; 4F-phenylboronic acid-Linker-maleimide and selenocysteine-nitroimidazole were linked by acid-amine condensation reaction, and then connected by Michael addition reaction to disodium mercapto dodecaborane ( 10 BSH), to obtain 4F-phenylboronic acid-maleimide-selenocysteine-nitroimidazole- 10 BSH (4F-PBA-L-Se-Se-MTZ- 10 BSH).

[0030] Preferably, the method for preparing the small molecule boron-10 carrier comprises the following steps: 1.2 mmol of phenylboronic acid derivative was dissolved in an organic solvent, followed by the addition of 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA), and then 1 mmol of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2) for reaction, concentration, and separation to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL; 4-carboxy-3-fluorophenylboronic acid-NH2-MAL was dissolved in an organic solvent, air was removed, and then a boron drug was added, the reaction was stirred at room temperature, purified, and freeze-dried to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL- 10 BSH (compound 1).

[0031] Preferably, the method for preparing the small molecule boron-10 carrier comprises the following steps: S1. Dissolve 1.2 mmol of 4-carboxyl-3-fluorophenylboronic acid in dimethylformamide (DMF), then add 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA), stir at room temperature for 30 min, then add 1 mmol of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2), react for 5 h, detect the completion of the reaction by TLC, concentrate under reduced pressure and separate by silica gel column chromatography to obtain 4-carboxyl-3-fluorophenylboronic acid-NH2-MAL; S2. Dissolve 1 mmol of 4-carboxyl-3-fluorophenylboronic acid-NH2-MAL in acetonitrile, remove air with nitrogen or argon, and then add 10 BSH, stirred at room temperature for 24 hours; after the reaction, it was purified by high performance liquid chromatography (HPLC) and freeze-dried to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL- 10 BSH (compound 1); Wherein, the structural formula of compound 1 is: .

[0032] Preferably, the method for preparing the small molecule boron-10 carrier comprises the following steps: 1 mmol of selenocystamine was dissolved in 5 ml of DMF, and 2 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) and 0.1 mmol of 4-dimethylaminopyridine (DMAP) were added. After reacting at room temperature for 1 hour, a nitroimidazole compound was added, reacted at room temperature overnight, and separated to obtain an intermediate product; then 1.2 mmol of N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine was dissolved in an organic solvent, and then 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl)urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) were added and dissolved in 5 ml of DMF, reacted at room temperature for 30 minutes, and then 1 mmol of the above intermediate product was added, reacted overnight, the solvent was spin-dried, and then purified by HPLC to obtain compound 2; Compound 2 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, reacted at room temperature, dried by rotary evaporation, the compound was precipitated, and the remaining solvent was naturally evaporated to obtain a first crude product; 1 mmol of a phenylboronic acid derivative was dissolved in 5 ml of DMF, 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) were added, and the reaction was carried out at room temperature for 30 min, and the first crude product was added, and the reaction was carried out at room temperature overnight, the solvent was dried by rotary evaporation, and then purified by HPLC to obtain a second crude product; the second crude product was dissolved in a methanol (CH3OH) solution containing 20% ​​N,N-diethylaniline (DEA), reacted at room temperature for 2 h, the solvent was dried by rotary evaporation, precipitated with ether, and the residual solvent was naturally evaporated, and then separated by HPLC to obtain compound 3; 1.2 mmol of compound 3 was dissolved in DMF, and then 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) were added, and the reaction was carried out at room temperature for 30 min. 1 mmol of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2) was added, and the reaction was carried out at room temperature overnight. The solvent was dried by spin drying, and the intermediate product was purified by HPLC. The intermediate product was dissolved in anhydrous acetonitrile and added 10 BSH, reacted at room temperature overnight, and purified by HPLC to obtain compound 4 (i.e., 4F-PBA-L-Se-Se-MTZ- 10 BSH), compound 4 is a small molecule boron-10 carrier.

[0033] Preferably, the method for preparing the small molecule boron-10 carrier comprises the following steps: S1. Dissolve 1 mmol of selenocystamine in 5 ml of DMF, add 2 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) and 0.1 mmol of 4-dimethylaminopyridine (DMAP), react at room temperature for 1 hour, add nitroimidazole compound, react at room temperature overnight, separate and obtain an intermediate product; then dissolve 1.2 mmol of N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine in an organic solvent, then add 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl)urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) and dissolve in 5 ml of DMF, react at room temperature for 30 minutes, then add 1 mmol of the above intermediate product, react overnight, spin dry the solvent, and then purify by HPLC to obtain compound 2; Among them, the structural formula of compound 2 is ; S2, compound 2 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, reacted at room temperature, dried by spin drying, precipitated the compound, and the remaining solvent was naturally evaporated to obtain a first crude product; 1mmol of phenylboronic acid derivative was dissolved in 5ml of DMF, 1.2mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6mmol of N,N-diisopropylethylamine (DIPEA) were added, and the reaction was carried out at room temperature for 30min, the first crude product was added, and the reaction was carried out at room temperature overnight, the solvent was dried by spin drying, and then purified by HPLC to obtain a second crude product; the second crude product was dissolved in a methanol (CH3OH) solution containing 20% ​​N,N-diethylaniline (DEA), reacted at room temperature for 2h, the solvent was dried by spin drying, precipitated with ether, and the residual solvent was naturally evaporated, and then separated by HPLC to obtain compound 3; Among them, the structural formula of compound 3 is ; S3. Dissolve (1.2 mmol) of compound 3 in DMF, then add (1.2 mmol) of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and (6 mmol) of N,N-diisopropylethylamine (DIPEA), react at room temperature for 30 min, add (1 mmol) of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2), react at room temperature overnight, spin dry the solvent, purify by HPLC to obtain an intermediate product; dissolve the intermediate product in anhydrous acetonitrile, add 10 BSH, reacted at room temperature overnight, and purified by HPLC to obtain compound 4 (4F-PBA-L-Se-Se-MTZ- 10 BSH), compound 4 is a small molecule boron-10 carrier.

[0034] Among them, the structural formula of compound 4 is .

[0035] Preferably, the organic solvent is selected from at least one of an alcohol organic solvent, an aprotic solvent, a halogenated hydrocarbon organic solvent, an ester organic solvent and an alkane organic solvent.

[0036] Preferably, the alcohol organic solvent is selected from at least one of methanol, ethanol, isopropanol and butanol.

[0037] Preferably, the halogenated hydrocarbon organic solvent is at least one selected from chloroform, dichloromethane and carbon tetrachloride.

[0038] Preferably, the ester organic solvent is selected from at least one of ethyl acetate, ethyl butyrate and ethyl formate.

[0039] Preferably, the alkane organic solvent is selected from at least one of n-hexane, cyclohexane and petroleum ether.

[0040] Preferably, the aprotic solvent is selected from at least one of acetonitrile, dimethylformamide, dimethyl sulfoxide and hexamethylphosphoric triamide.

[0041] The present invention also provides an application of a small molecule boron-10 carrier, and the application of the small molecule boron-10 carrier in the preparation of a drug for BNCT treatment of tumors.

[0042] The small molecule boron-10 carrier of the present invention does not need any auxiliary materials to be added when actually used, and can be directly dissolved in physiological saline or phosphate buffer solution or sterile water or glucose solution to prepare a boron medicine preparation for infusion.

[0043] Preferably, the tumor includes at least one of malignant melanoma, head and neck squamous cell carcinoma, glioma, nasopharyngeal carcinoma and breast cancer.

[0044] Preferably, the tumor includes at least one of metastatic melanoma, recurrent melanoma, advanced melanoma, metastatic head and neck squamous cell carcinoma, recurrent head and neck squamous cell carcinoma, advanced head and neck squamous cell carcinoma, metastatic brain glioma, recurrent brain glioma and advanced brain glioma.

[0045] Beneficial effects of the present invention: The small molecule boron-10 carrier of the present invention can prolong the drug tumor retention time and increase the tumor boron drug enrichment concentration, has better biological permeability and better targeting selectivity, effectively enhances the killing of tumor cells by high-energy particles, and solves the problem of incomplete treatment caused by cell DNA repair after BNCT treatment; innovatively proposes phenylboronic acid derivatives to improve targeting, diselenide compounds to induce cancer cells to produce ROS, and nitroimidazole compounds to inhibit DNA damage repair, thereby enhancing the BNCT treatment effect, and has a high prospect for clinical transformation; The invention discloses an intravenously injectable small molecule boron-containing drug, which is synthesized from a phenylboronic acid derivative through a series of acid-amine condensation reactions and Markel addition reactions, and improves the therapeutic effect of BNCT; it has the advantages of relatively low cost, simple preparation process, good biocompatibility and good targeting; it can reduce the toxic and side effects of the drug and improve the BNCT efficacy; it can generate ROS to damage DNA chains and cause cell apoptosis while generating high-energy particles, and nitroimidazole inhibits DNA repair and increases the level of oxidative stress, and significantly enhances the efficacy; it has popularization and application value in the technical field of development of new boron drugs for BNCT. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is the compound 4F-PBA-MAL in Example 1 1 H NMR spectra; Figure 2 The compound 4F-PBA-MAL- 10 MS map of BSH; Figure 3 4F-PBA-MAL- 10 After BSH was co-cultured with B16F10 cells for 1 h, the cells 10 B is the result of the uptake; Figure 4 4F-PBA-MAL- 10 After BSH and B16F10 cells were co-cultured for 1, 2, and 4 h, the cells 10 B is the result of the uptake; Figure 5 4F-PBA-MAL- 10 After BSH and GL261 cells were co-cultured for 1, 2, and 4 h, the cells 10 B is the result of the uptake; Figure 6 4F-PBA-MAL- 10 Relative cell survival rate after BSH and B16F10 cells were co-cultured for 48 h; Figure 7 4F-PBA-MAL- 10 Relative cell survival rate after BSH and GL261 cells were co-cultured for 48 h; Figure 8 PBS, BSH and 4F-PBA-MAL- 10 Relative cell survival rate of BSH after co-culture with B16F10 cells for 48 h with or without BNCT irradiation; Fig. 9 PBS and 4F-PBA-MAL- 10 Relative cell survival rate of BSH after co-culture with GL261 cells for 48 h with or without BNCT irradiation; Fig.10 PBS and 4F-PBA-MAL- 10 BSH Plate cloning experiment results of B16F10 cells with or without BNCT irradiation; Fig.11 This is a plate colony count graph; Fig.12 PBS and 4F-PBA-MAL- 10 BSH apoptosis test results of B16F10 cells with or without BNCT irradiation; Fig.13PBS and 4F-PBA-MAL- 10 BSH apoptosis experiment results of GL261 cells with or without BNCT irradiation; Fig.14 For injection of 4F-PBA-MAL- 10 Figure 1: Results of an in vivo imaging experiment to evaluate the therapeutic effect of BSH on GL261 tumor-bearing mice after BNCT irradiation 1 hour after BSH. DETAILED DESCRIPTION

[0047] The following will describe the embodiments of the present invention with reference to the preferred embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention, not for limiting the scope of protection of the present invention.

[0048] The present invention intends to disclose a small molecule boron-10 carrier, a preparation method and an application thereof, so as to solve the problems of limited therapeutic effect and difficulty in inhibiting DNA damage repair in the existing BNCT, and to provide a new boron drug option for enhancing the efficacy of BNCT.

[0049] Among them, the small molecule boron-10 carrier, the compound whose structural formula is shown in formula (I) and its racemate, stereoisomer, tautomer or pharmaceutically acceptable salt; (I) In formula (I), C is selected from ; L is selected from .

[0050] The small molecule boron-10 carrier of the above structure can target tumor cells. Phenylboronic acid derivatives can react with sialic acid highly expressed on the surface of tumor cells. Glycolysis is the main metabolic mode of tumor cell metabolism. Tumor cells tend to obtain energy through glycolysis in aerobic or anaerobic conditions, and glycolysis mainly decomposes glucose. Compared with normal cells, tumor cells have more vigorous metabolism, so the uptake of glucose is more significant; phenylboronic acid will form a boric acid ester bond with glucose to prolong the tumor retention time and increase the concentration of tumor boron drug enrichment, thereby enhancing the selective accumulation of drugs.

[0051] In some embodiments, the small molecule boron-10 carrier is made of at least one of a boron drug, a phenylboronic acid derivative, a selenium-containing compound, and a DNA repair inhibitor. Among them, the component that increases targeting and biopermeability is selected in this embodiment as 4-carboxy-3-fluorophenylboronic acid, and the component that inhibits DNA damage repair is selected as 2-(2-methyl-5-nitro-1H-imidazole-1-yl)acetic acid, and the BNCT irradiation drug is selected as 10 BSH.

[0052] In some embodiments, the phenylboronic acid derivative is selected from at least one of 4-carboxy-3-fluorophenylboronic acid, 4-carboxy-phenylboronic acid, and 5-fluoro-dimethyl-phenylboronic acid.

[0053] Among them, the structural formula of 4-carboxyl-3-fluorophenylboronic acid is .

[0054] The structural formula of 4-carboxyl-phenylboronic acid is .

[0055] The structural formula of 5-fluoro-dimethyl-phenylboronic acid is .

[0056] Exemplarily, the phenylboronic acid derivative is selected from 4-carboxy-3-fluorophenylboronic acid.

[0057] In some embodiments, the boron drug is selected from disodium mercapto dodecaborane ( 10 BSH) and L-borylphenylalanine ( 10 BPA) or both.

[0058] In some embodiments, the selenium-containing compound is selected from at least one of L-selenocysteine, seleno-DL-cystine, and selenocystamine.

[0059] Among them, the structural formula of L-selenocysteine ​​is .

[0060] The structural formula of seleno-DL-cystine is .

[0061] The structural formula of selenocystamine is .

[0062] Exemplarily, the DNA repair inhibiting compound is selected from nitroimidazole compounds.

[0063] Among them, nitroimidazole compounds have electrophilic properties. Under the activation of bioreductase in the hypoxic environment of tumors, their electrophilicity becomes stronger and they can directly combine with nucleophilic biomacromolecule free radicals (such as nucleic acids, proteins, etc.) generated by radiation, making it impossible for tumor cells to repair themselves, thereby accelerating their death.

[0064] In some embodiments, the nitroimidazole compound is selected from at least one of metronidazole, ornidazole, and 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid.

[0065] Among them, the structural formula of metronidazole is .

[0066] The structural formula of ornidazole is .

[0067] The structural formula of 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid is .

[0068] Exemplarily, the nitroimidazole compound is selected from 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid.

[0069] In some embodiments, a method for preparing a small molecule boron-10 carrier is also provided, comprising the following steps: The phenylboronic acid derivative and N-(2-aminoethyl)maleimide hydrochloride are connected through acid-amine condensation, and then the boron drug is covalently coupled through an addition reaction, and then purified to obtain a small molecule boron-10 carrier.

[0070] In some embodiments, a method for preparing a small molecule boron-10 carrier is also provided, comprising the following steps: Connecting N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine, N-(2-aminoethyl)maleimide hydrochloride and phenylboronic acid derivatives through acid-amine condensation, rotary evaporation and purification to obtain a first intermediate; The selenium-containing compound and the DNA repair inhibiting compound are connected by esterification reaction, and purified to obtain a second intermediate; The first intermediate and the second intermediate are connected through an acid-amine condensation reaction, and then connected to a boron drug through an addition reaction to obtain a small molecule boron-10 carrier.

[0071] In some embodiments, a method for preparing a small molecule boron-10 carrier comprises the following steps: connecting 4-carboxy-3-fluorophenylboronic acid and N-(2-aminoethyl)maleimide hydrochloride by acid-amine condensation, and then covalently coupling by Michael addition reaction. 10 BSH was evaporated and purified by HPLC to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL- 10 BSH (4F-PBA-MAL- 10 BSH).

[0072] In some embodiments, the preparation method of a small molecule boron-10 carrier comprises the following steps: connecting N2-(((9H-fluoren-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine and N-(2-aminoethyl)maleimide hydrochloride and 4-carboxy-3-fluorophenylboronic acid through acid-amine condensation, rotary evaporation, and HPLC purification to obtain 4F-phenylboronic acid-Linker-maleimide; Selenocysteine ​​and 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid are connected by esterification reaction, and then subjected to rotary evaporation and HPLC purification to obtain selenocysteine-nitroimidazole; The above two compounds are connected by acid amine condensation reaction, and then connected by Michael addition reaction to disodium mercapto dodecaborane ( 10 BSH), to obtain 4F-phenylboronic acid-maleimide-selenocysteine-nitroimidazole- 10 BSH (4F-PBA-L-Se-Se-MTZ- 10 BSH).

[0073] In some embodiments, the preparation method of the small molecule boron-10 carrier comprises the following steps: The phenylboronic acid derivative is dissolved in DMF, and then N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and N,N-diisopropylethylamine (DIPEA) are added, and then N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2) is added to react, concentrated, and separated to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL; 4-carboxy-3-fluorophenylboronic acid-NH2-MAL is dissolved in an organic solvent, air is removed, and then a boron drug is added, the reaction is stirred at room temperature, purified, and freeze-dried to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL- 10 BSH (compound 1).

[0074] An exemplary method for preparing a small molecule boron-10 carrier comprises the following steps: S1. Dissolve 1.2 mmol of 4-carboxyl-3-fluorophenylboronic acid in dimethylformamide (DMF), then add 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA), stir at room temperature for 30 min, then add 1 mmol of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2), react for 5 h, detect the completion of the reaction by TLC, concentrate under reduced pressure and separate by silica gel column chromatography to obtain 4-carboxyl-3-fluorophenylboronic acid-NH2-MAL; S2. Dissolve 1 mmol of 4-carboxyl-3-fluorophenylboronic acid-NH2-MAL in acetonitrile, remove air with nitrogen or argon, and then add 10 BSH, stirred at room temperature for 24 hours; after the reaction, it was purified by high performance liquid chromatography (HPLC) and freeze-dried to obtain compound 1 (4-carboxy-3-fluorophenylboronic acid-NH2-MAL- 10 BSH); Wherein, the structural formula of compound 1 is: .

[0075] In some embodiments, the preparation method of the small molecule boron-10 carrier comprises the following steps: 1 mmol of selenocystamine was dissolved in 5 ml of DMF, 2 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) and 0.1 mmol of 4-dimethylaminopyridine (DMAP) were added, and the mixture was reacted at room temperature for 1 hour. Then, a nitroimidazole compound was added, and the mixture was reacted at room temperature overnight. The mixture was separated to obtain an intermediate product. Then, (1.2 mmol) of N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine was dissolved in an organic solvent, and then 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl)urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) were added and dissolved in 5 ml of DMF. The mixture was reacted at room temperature for 30 minutes. Then, 1 mmol of the intermediate product was added, and the mixture was reacted overnight. The solvent was dried by spin drying, and then purified by HPLC to obtain compound 2. Compound 2 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, reacted at room temperature, dried by rotary evaporation, the compound was precipitated, and the remaining solvent was naturally evaporated to obtain a first crude product; 1 mmol of a phenylboronic acid derivative was dissolved in 5 ml of DMF, 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) were added, and the reaction was carried out at room temperature for 30 min, and the first crude product was added, and the reaction was carried out at room temperature overnight, the solvent was dried by rotary evaporation, and then purified by HPLC to obtain a second crude product; the second crude product was dissolved in a methanol (CH3OH) solution containing 20% ​​N,N-diethylaniline (DEA), reacted at room temperature for 2 h, the solvent was dried by rotary evaporation, precipitated with ether, and the residual solvent was naturally evaporated, and then separated by HPLC to obtain compound 3; 1.2 mmol of compound 3 was dissolved in DMF, and then 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) uronium hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) were added, and the reaction was carried out at room temperature for 30 min. 1 mmol of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2) was added, and the reaction was carried out at room temperature overnight. The solvent was spin-dried and purified by HPLC to obtain an intermediate product. The intermediate product was dissolved in anhydrous acetonitrile, 10BSH was added, the reaction was carried out at room temperature overnight, and HPLC was purified to obtain compound 4, which is a small molecule boron-10 carrier.

[0076] An exemplary method for preparing a small molecule boron-10 carrier comprises the following steps: S3, 1mmol of selenocystamine was dissolved in 5ml of DMF, 2mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) and 0.1mmol of 4-dimethylaminopyridine (DMAP) were added, and the reaction was continued at room temperature for 1h, and then a nitroimidazole compound was added, and the reaction was continued at room temperature overnight, and the intermediate product was obtained after separation; then (1.2mmol) of N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-( tert-Butyloxycarbonyl)-L-lysine was dissolved in an organic solvent, followed by the addition of (1.2 mmol) of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) dissolved in 5 ml of DMF, and reacted at room temperature for 30 min, then 1 mmol of the above intermediate was added, reacted overnight, the solvent was spin-dried, and then purified by HPLC to obtain compound 2; Among them, the structural formula of compound 2 is ; S4, compound 2 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, reacted at room temperature, dried by spin drying, precipitated the compound, and the remaining solvent was naturally evaporated to obtain a first crude product; 1mmol of phenylboronic acid derivative was dissolved in 5ml of DMF, 1.2mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6mmol of N,N-diisopropylethylamine (DIPEA) were added, and the reaction was carried out at room temperature for 30min, the first crude product was added, and the reaction was carried out at room temperature overnight, the solvent was dried by spin drying, and then purified by HPLC to obtain a second crude product; the second crude product was dissolved in a methanol (CH3OH) solution containing 20% ​​N,N-diethylaniline (DEA), reacted at room temperature for 2h, the solvent was dried by spin drying, precipitated with ether, and the residual solvent was naturally evaporated, and then separated by HPLC to obtain compound 3; Among them, the structural formula of compound 3 is ; S5. Dissolve 1.2 mmol of compound 3 in DMF, then add 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA), react at room temperature for 30 min, add 1 mmol of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2), react at room temperature overnight, spin dry the solvent, purify by HPLC to obtain an intermediate product; dissolve the intermediate product in anhydrous acetonitrile, add 10 BSH, reacted at room temperature overnight, and purified by HPLC to obtain compound 4 (i.e., 4F-phenylboronic acid-maleimide-selenocysteine-nitroimidazole- 10 BSH), compound 4 is a small molecule boron-10 carrier.

[0077] Among them, the structural formula of compound 4 is .

[0078] In some embodiments, the organic solvent is selected from at least one of an alcohol organic solvent, an aprotic solvent, a halogenated hydrocarbon organic solvent, an ester organic solvent, and an alkane organic solvent.

[0079] In some embodiments, the alcohol organic solvent is selected from at least one of methanol, ethanol, isopropanol and butanol.

[0080] In some embodiments, the halogenated hydrocarbon organic solvent is selected from at least one of chloroform, dichloromethane and carbon tetrachloride.

[0081] In some embodiments, the ester organic solvent is selected from at least one of ethyl acetate, ethyl butyrate and ethyl formate.

[0082] In some embodiments, the alkane organic solvent is selected from at least one of n-hexane, cyclohexane and petroleum ether.

[0083] In some embodiments, the aprotic solvent is selected from at least one of acetonitrile, dimethylformamide, dimethyl sulfoxide, and hexamethylphosphoric triamide.

[0084] In some embodiments, a small molecule boron-10 carrier is provided for use in the preparation of a drug for BNCT treatment of tumors.

[0085] The small molecule boron-10 carrier obtained in the above examples does not require any auxiliary materials to be added during actual use, and can be directly dissolved in physiological saline, phosphate buffer solution, sterile water or glucose solution to prepare a boron drug preparation for infusion.

[0086] In some embodiments, the tumor comprises at least one of malignant melanoma, head and neck squamous cell carcinoma, glioma, nasopharyngeal carcinoma, and breast cancer.

[0087] In some embodiments, the tumor comprises at least one of metastatic melanoma, recurrent melanoma, advanced melanoma, metastatic head and neck squamous cell carcinoma, recurrent head and neck squamous cell carcinoma, advanced head and neck squamous cell carcinoma, metastatic glioma, recurrent glioma, and advanced glioma.

[0088] In order to make the technical problems, technical solutions and beneficial effects solved by the present application clearer, the preparation method of the small molecule boron-10 carrier of the present invention will be further described in detail below in conjunction with specific embodiments and drawings. Obviously, the specific embodiments described are only part of the embodiments of the present application, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present application and its application. Based on the specific embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work belong to the scope of protection of the present application.

[0089] If no specific techniques or conditions are specified in the specific embodiments, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0090] The sources of the main materials and reagents used in the following examples are as follows: 4-Carboxy-3-fluorophenylboronic acid, selenocystamine, N2-(((9H-fluoren-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine, HATU, DIPEA, dichloromethane, DMF, 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid, N-(2-aminoethyl)maleimide hydrochloride, di-tert-butyl dicarbonate, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI), 4-dimethylaminopyridine (DMAP), acetonitrile and methanol (CH3OH) were purchased from Aladdin, and BSH was purchased from the Czech Republic.

[0091] Example 1 A method for preparing a small molecule boron-10 carrier comprises the following steps: S1. Dissolve 1.2 mmol of phenylboronic acid derivative in DMF, then add 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA), and then add 1 mmol of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2) to react, concentrate, and separate to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL (i.e., 4F-PBA-MAL); S2, dissolve 1 mmol of 4-carboxyl-3-fluorophenylboronic acid-NH2-MAL in acetonitrile, pass nitrogen to remove air, and then add 10 BSH, stirred at room temperature for 24 hours; after the reaction, HPLC purification was performed and freeze-dried to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL- 10 BSH (compound 1), namely 4F-PBA-MAL- 10 BSH; Among them, the structural formula of compound 1 is .

[0092] Example 2 A method for preparing a small molecule boron-10 carrier comprises the following steps: S1. Dissolve 1 mmol of selenocystamine in 5 ml of DMF, add 2 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) and 0.1 mmol of 4-dimethylaminopyridine (DMAP), react at room temperature for 1 hour, add nitroimidazole compound, react at room temperature overnight, separate and obtain an intermediate product; then dissolve 1.2 mmol of N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine in an organic solvent, then add 1.2 mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl)urea hexafluorophosphate (HATU) and 6 mmol of N,N-diisopropylethylamine (DIPEA) and dissolve in 5 ml of DMF, react at room temperature for 30 minutes, then add 1 mmol of the above intermediate product, react overnight, spin dry the solvent, and then purify by HPLC to obtain compound 2; S2, compound 2 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, reacted at room temperature, dried by spin drying, precipitated the compound, and the remaining solvent was naturally evaporated to obtain a first crude product; 1mmol of phenylboronic acid derivative was dissolved in 5ml of DMF, (1.2mmol) of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6mmol of N,N-diisopropylethylamine (DIPEA) were added, reacted at room temperature for 30min, the first crude product was added, reacted at room temperature overnight, the solvent was dried by spin drying, and then purified by HPLC to obtain a second crude product; the second crude product was dissolved in a methanol (CH3OH) solution containing 20% ​​N,N-diethylaniline (DEA), reacted at room temperature for 2h, the solvent was dried by spin drying, precipitated with ether, the residual solvent was naturally evaporated, and then separated by HPLC to obtain compound 3; S3, 1.2mmol of compound 3 was dissolved in DMF, and then 1.2mmol of N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate (HATU) and 6mmol of N,N-diisopropylethylamine (DIPEA) were added, and the reaction was carried out at room temperature for 30min, and 1mmol of N-(2-aminoethyl)maleimide hydrochloride (MAL-NH2) was added, and the reaction was carried out at room temperature overnight. The solvent was spin-dried and purified by HPLC to obtain an intermediate product; the intermediate product was dissolved in anhydrous acetonitrile and added 10 BSH, reacted at room temperature overnight, and purified by HPLC to obtain compound 4 (4F-PBA-L-Se-Se-MTZ- 10 BSH), compound 4 is a small molecule boron-10 carrier; Among them, the structural formula of compound 4 is .

[0093] Detection and analysis 1) Nuclear magnetic resonance hydrogen spectrum analysis The compound 4-fluorophenylboronic acid-maleimide prepared in Example 1 was subjected to nuclear magnetic resonance analysis, and the results were as follows: Figure 1 shown.

[0094] from Figure 1 From the analysis, we can see that the target compound was synthesized correctly and the target peak has been marked in the figure.

[0095] 2) Mass spectrometry analysis The compound 4F-PBA-MAL- 10 BSH was subjected to mass spectrometry analysis, and the results were as follows Figure 2 shown.

[0096] from Figure 2 From the analysis, we can see that there is an obvious M / 2 peak in the figure, indicating that it is the target compound.

[0097] 3) 4F-PBA-MAL- 10 BSH intake The 4F-PBA-MAL- 10 The results of BSH uptake in the nuclei of B16F10 cells after 1, 2, and 4 hours of co-culture are shown in the figure. Figure 3 and Figure 4 shown.

[0098] from Figure 3 From the analysis, we can see that 4F-PBA-MAL- 10 BSH boron medicine has the best effect when the boron concentration is 100 ng / mL. Figure 4 From the analysis, we can see that 4F-PBA-MAL- 10 BSH boron drug has a better uptake effect than BSH, and the uptake reaches the highest level at 1 hour.

[0099] The 4F-PBA-MAL- 10 The results of BSH uptake in the nuclei of GL261 cells after 1, 2, and 4 hours of co-culture are shown in Figure 2. Figure 5 shown.

[0100] from Figure 5 From the analysis, we can see that 4F-PBA-MAL- 10 BSH boron medicine has the best effect when the boron concentration is 100 ng / mL and the intake time is 1 hour.

[0101] 4) CCK-8 assay to evaluate 4F-PBA-MAL- 10 Biosafety of BSH When B16F10 cells and GL216 cells (purchased from ATCC Cell Bank, USA) were in the logarithmic growth phase, the cells at the bottom of the culture dish were digested with trypsin, centrifuged and resuspended to make a cell suspension. The cells were counted using a cell counting plate and 2×10 3 The cells were plated into a 96-well plate at a density of 100 cells / well and incubated in an incubator at 37°C with 5% CO2 for 24 h. Then, 4F-PBA-MAL- 10BSH, and continue to culture for 24 hours. After 24 hours, take out the 96-well plate, discard the original culture medium, add 100 μL of culture medium containing CCK-8 reagent to each well (the volume ratio of CCK-8 reagent to RPMI 1640 culture medium is 1:9), and then continue to culture in the incubator for 2-4 hours. Finally, use an enzyme reader to detect the absorbance of each group at 450 nm. According to the formula: survival rate = (experimental group-blank control group) / (negative control group-blank control group)×100%, calculate the cell survival rate, and use Excel 2013 and GraphPad PrismV8.0 software to plot the obtained data. The results are shown in Figure 6 and Figure 7 shown.

[0102] from Figure 6 and Figure 7 It can be seen that 4F-PBA-MAL- 10 BSH drugs have no obvious toxic side effects on cells and have good biosafety.

[0103] 5) BNCT irradiation experiment The cells were divided into: a non-irradiated and non-drug group, an irradiated group, and an irradiated group with 4F-PBA-MAL- 10 BSH boron drug group 3. According to the optimal uptake time selected by the cell experiment, the drug was added to the cell culture dish in advance for cell uptake. After the uptake was completed, the drug-containing culture medium was aspirated and rinsed with PBS, pancreatic enzyme was added to digest the cells and centrifuged, the cells were resuspended with 200 μL culture medium, added to a 200 μL centrifuge tube, and then BNCT irradiation was performed.

[0104] 6) Study on cytotoxicity after BNCT irradiation After neutron irradiation, B16F10 cells were diluted to 1000 cells / 100 μL and seeded on a 96-well plate. After attachment, 10 μL of CCK-8 solution was added at 24, 48, 72, and 96 h. After incubation at 37 °C for 2 h, the optical density of each sample at 450 nm was measured to calculate the cell survival rate. Figure 8 As shown; from Figure 8 It can be seen that the 4F-PBA-MAL- 10 After BNCT irradiation, the toxicity of BSH boron drug to B16F10 cells increased significantly, indicating that this boron drug had a significant killing effect on B16F10 cells after BNCT irradiation; After neutron irradiation, GL261 cells were diluted to 1000 cells / 100 μL and seeded on a 96-well plate. After attachment, 10 μL of CCK-8 solution was added at 24, 48, 72, and 96 h. After incubation at 37 °C for 2 h, the optical density of each sample at 450 nm was measured to calculate the cell survival rate. Fig. 9 As shown; from Fig. 9 It can be seen that the 4F-PBA-MAL- 10 After BNCT irradiation, the toxicity of BSH boron drug to GL261 cells increased significantly, indicating that this boron drug had a significant killing effect on GL261 cells after BNCT irradiation; 7) Experimental study on cell clone formation after BNCT irradiation After neutron irradiation, the cells were graded diluted to 200 cells / well, and each group was plated in a six-well plate (six parallels), and 2 mL of culture medium was added to each well. The culture was terminated after 7 days. The culture medium was aspirated, washed three times with PBS, fixed with 1 mL of paraformaldehyde for 30 minutes, aspirated, washed three times with PBS, and then stained with 1 mL of crystal violet for 30 minutes. After the crystal violet was washed clean with PBS, it was dried in air, and the number of cell clones was counted with the naked eye. Fig.10 and Fig.11 As shown; Inoculation efficiency = (number of clones in the control group / number of cells inoculated) × 100% Survival rate = [number of clones in the experimental group / (number of inoculated cells × inoculation efficiency)] × 100% from Fig.10 and Fig.11 It can be seen that the 4F-PBA-MAL- 10 After BSH boron drug was irradiated by BNCT, the colony of B16F10 cells was significantly reduced, indicating that this boron drug had a significant killing effect on B16F10 cells after BNCT irradiation.

[0105] 8) Experimental study on cell apoptosis after BNCT irradiation After neutron irradiation, the cells were diluted to 1*10^ 5 Cells / well, each group was plated in a six-well plate (six parallels), 2 mL of culture medium was added to each well, and the culture was terminated after 48 hours. The culture medium was aspirated, washed three times with PBS, digested with trypsin and discarded the supernatant, washed three times with pre-cooled PBS, 300 μL of 1×Binding Buffer was added to suspend the cells, 5 μL of Annexin V-FITC and 5 μL of PI were added to stain and mixed, protected from light, incubated at room temperature for 15 minutes, and then 300 μL of 1×Binding Buffer was added. Finally, the cells were detected by flow cytometry. The results are shown in the figure. Fig.12 and Fig.13 shown.

[0106] from Fig.12 and Fig.13 It can be seen that the 4F-PBA-MAL- 10 After BSH boron drug was irradiated by BNCT, the apoptosis rate of cells was significantly increased.

[0107] 9) Experiment on GL261 tumor-bearing mice after BNCT irradiation The GL261 tumor-bearing mice were divided into a control group, a BNCT irradiation group, and a boron drug irradiation group. The boron drug irradiation group was injected with 4F-PBA-MAL- 10 BSH boron drug, BNCT irradiation was performed 1 hour later. The growth of mice was monitored and evaluated after BNCT to evaluate the effectiveness of BNCT. In vivo fluorescence imaging of mice was performed every 7 days. The results are shown in Fig.14 shown.

[0108] from Fig.14 It can be seen that the 4F-PBA-MAL- 10 BSH boron drug has a significant inhibitory effect on brain glioma, and the tumor inhibition effect of the neutron irradiation group alone is poor as time goes by.

[0109] In summary, the present invention provides an intravenously injectable small molecule boron-containing drug, which is synthesized from a phenylboronic acid derivative through a series of acid-amine condensation reactions and Markel addition reactions, to improve the therapeutic effect of BNCT. It has the advantages of relatively low cost, simple preparation process, good biocompatibility, and good targeting; it can reduce the toxic and side effects of drugs and improve the efficacy of BNCT; while generating high-energy particles, it can also generate ROS to damage DNA chains and cause cell apoptosis, and nitroimidazole inhibits DNA repair, increases the level of oxidative stress, and significantly enhances the efficacy. It has the value of promotion and application in the development of new boron drugs for BNCT.

[0110] The above embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent substitution or change made by a person skilled in the art based on the present invention is within the protection scope of the present invention.

Claims

1. A small molecule boron-10 carrier, characterized in that: The compound whose structural formula is shown in formula (I) and its racemate, stereoisomer or tautomer; （I） In formula (I), C is selected from ; L is selected from .

2. The small molecule boron-10 carrier according to claim 1, characterized in that: The invention is prepared from boron drugs, and at least one of phenylboronic acid derivatives, selenium-containing compounds and DNA repair inhibition compounds.

3. The small molecule boron-10 carrier according to claim 2, characterized in that: The phenylboronic acid derivative is selected from at least one of 4-carboxy-3-fluorophenylboronic acid, 4-carboxy-phenylboronic acid and 5-fluoro-dimethyl-phenylboronic acid; And / or, the boron drug is selected from one or two of disodium mercaptododecaborane and L-para-borylphenylalanine; And / or, the selenium-containing compound is selected from at least one of L-selenocysteine, seleno-DL-cystine, and selenocystamine; And / or, the DNA repair inhibiting compound is selected from nitroimidazole compounds.

4. The small molecule boron-10 carrier according to claim 3, characterized in that: The nitroimidazole compound is at least one selected from metronidazole, ornidazole and 2-(2-methyl-5-nitro-1H-imidazol-1-yl)acetic acid.

5. The method for preparing the small molecule boron-10 carrier according to any one of claims 1 to 4, characterized in that: The following steps are involved: The phenylboronic acid derivative and N-(2-aminoethyl)maleimide hydrochloride are connected by acid-amine condensation, and then the boron drug is covalently coupled by addition reaction, and purified to obtain a small molecule boron-10 carrier; Alternatively, N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine and N-(2-aminoethyl)maleimide hydrochloride and phenylboronic acid derivative are connected by acid-amine condensation, rotary evaporation, and purification to obtain a first intermediate; The selenium-containing compound and the DNA repair inhibiting compound are connected by esterification reaction, and purified to obtain a second intermediate; The first intermediate and the second intermediate are connected through an acid-amine condensation reaction, and then connected to a boron drug through an addition reaction to obtain a small molecule boron-10 carrier.

6. The method for preparing the small molecule boron-10 carrier according to claim 5, characterized in that: The following steps are involved: The phenylboronic acid derivative is dissolved in an organic solvent, and then N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate and N,N-diisopropylethylamine are added, and then N-(2-aminoethyl)maleimide hydrochloride is added to react, concentrate, and separate to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL; 4-carboxy-3-fluorophenylboronic acid-NH2-MAL is dissolved in an organic solvent, air is removed, and then a boron drug is added, the reaction is stirred at room temperature, purified, and freeze-dried to obtain 4-carboxy-3-fluorophenylboronic acid-NH2-MAL- 10 BSH, ie 4F-PBA-MAL- 10 BSH; Alternatively, selenocystamine is dissolved in 5 ml of DMF, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 4-dimethylaminopyridine are added, and the mixture is reacted at room temperature for 1 hour. A nitroimidazole compound is added, and the mixture is reacted overnight at room temperature, and then separated to obtain an intermediate product; then N2-(((9H-fluorene-9-yl)methoxy)carbonyl)-N6-(tert-butoxycarbonyl)-L-lysine is dissolved in an organic solvent, and then N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl)urea hexafluorophosphate and N,N-diisopropylethylamine are added and dissolved in 5 ml of DMF, and the mixture is reacted at room temperature for 30 minutes. The intermediate product is then added, and the mixture is reacted overnight. The solvent is then spin-dried, and then purified by HPLC to obtain compound 2; Compound 2 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, reacted at room temperature, dried by rotary evaporation, the compound was precipitated, and the remaining solvent was naturally evaporated to obtain a first crude product; a phenylboronic acid derivative was dissolved in DMF, N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate and N,N-diisopropylethylamine were added, reacted at room temperature for 30 minutes, the first crude product was added, reacted at room temperature overnight, the solvent was dried by rotary evaporation, and then purified by HPLC to obtain a second crude product; the second crude product was dissolved in a methanol solution containing 20% ​​N,N-diethylaniline, reacted at room temperature for 2 hours, the solvent was dried by rotary evaporation, precipitated with ether, and the residual solvent was naturally evaporated, and then separated by HPLC to obtain compound 3; Compound 3 was dissolved in DMF, and then N,N,N′,N′-tetramethyl-O-(7-azabenzotriazole-1-yl) urea hexafluorophosphate and N,N-diisopropylethylamine were added, and the reaction was carried out at room temperature for 30 minutes. N-(2-aminoethyl)maleimide hydrochloride was added, and the reaction was carried out at room temperature overnight. The solvent was spin-dried and purified by HPLC to obtain an intermediate product. The intermediate product was dissolved in anhydrous acetonitrile and added 10 BSH, reacted at room temperature overnight, and purified by HPLC to obtain 4F-phenylboronic acid-maleimide-selenocysteine-nitroimidazole- 10 BSH, i.e. 4F-PBA-L-Se-Se-MTZ- 10 BSH.

7. The method for preparing the small molecule boron-10 carrier according to claim 6, characterized in that: The organic solvent is selected from at least one of an alcohol organic solvent, an aprotic solvent, a halogenated hydrocarbon organic solvent, an ester organic solvent and an alkane organic solvent.

8. The method for preparing the small molecule boron-10 carrier according to claim 7, characterized in that: The alcohol organic solvent is selected from at least one of methanol, ethanol, isopropanol and butanol; And / or, the halogenated hydrocarbon organic solvent is selected from at least one of chloroform, dichloromethane and carbon tetrachloride; And / or, the ester organic solvent is selected from at least one of ethyl acetate, ethyl butyrate and ethyl formate; And / or, the alkane organic solvent is selected from at least one of n-hexane, cyclohexane and petroleum ether; And / or, the aprotic solvent is selected from at least one of acetonitrile, dimethylformamide, dimethyl sulfoxide and hexamethylphosphoric triamide.

9. The use of a small molecule boron-10 carrier according to any one of claims 1 to 4, characterized in that: The small molecule boron-10 carrier is used in the preparation of BNCT drugs for treating tumors.

10. The use according to claim 9, characterized in that: The tumor includes at least one of malignant melanoma, head and neck squamous cell carcinoma, glioma, nasopharyngeal carcinoma and breast cancer; And / or, the tumor includes at least one of metastatic melanoma, recurrent melanoma, advanced melanoma, metastatic head and neck squamous cell carcinoma, recurrent head and neck squamous cell carcinoma, advanced head and neck squamous cell carcinoma, metastatic brain glioma, recurrent brain glioma and advanced brain glioma.

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