Multi-boron complex as well as preparation and application thereof

Abstract

The invention provides a multi-boron complex or a stereoisomer, a deuterated compound or a pharmaceutically acceptable salt thereof, and preparation and application thereof. The multi-boron complex provided by the invention is relatively low in biotoxicity, and has relatively high T / B ratio and boron enrichment in tumor cells. Structure of multi-boron complex is as shown in formula (I): # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the field of medicine. Specifically, the present invention relates to a multi-boron complex and its preparation and application. Background Art

[0002] Boron neutron capture therapy (BNCT) is a promising radiotherapy technique that selectively delivers boron-10-rich 10 drugs into cancer cells and then irradiates them with low-energy neutrons, resulting in highly localized nuclear fission reactions that release energy and induce cell death. Since the energy deposition is limited to the diameter of a single cell, tumor cells with significant boron accumulation will be damaged, leaving the surrounding healthy cells unaffected. So far, boron compounds have been continuously improved to produce ideal BNCT compounds that can selectively target tumor cells and have a longer retention time within tumor cells.

[0003] First-generation boron compounds: In the early 1950s, compounds such as boric acid, borax, and pentaborate were synthesized, but it was observed that their concentrations in tumors were very low compared to those in the brain, and their accumulation times were short. Second-generation boron compounds: In the 1960s, two of the most effective and prominent boron compounds emerged, namely boronophenylalanine (BPA) and sodium borocaptate (BSH). They are significantly less toxic in animal tumors and have a longer duration in relevant molecules. In addition, the boron concentration ratios in tumor / brain and tumor / blood are both greater than 1. Therefore, they have been authorized for clinical trials.

[0004] Compared with BSH, which has no tumor-targeting ability, BPA is the most successful compound in current clinical trials, but its low solubility has always been a major problem in BNCT. Even ([[]] 18 F)F-BPA is more lipid-soluble due to the presence of lipophilic fluorine. However, the borate ester complex between BPA and monosaccharides significantly improves its water solubility and has quickly entered clinical use for the treatment of patients with high-grade gliomas. In addition to the solubility problem, BPA also has other problems in BNCT: when exposed to sufficient concentrations of reactive oxygen species (ROS) generated in biological systems, such as hydrogen peroxide, peroxynitrite, oxygen free radicals, etc., boric acid undergoes metabolic instability. Compared with normal cells, cancer cells produce more ROS, thus reducing the 10 accumulation of boron in cancer cells.

[0005] The success of binary radiotherapy depends on the selective absorption of boron-containing preparations with therapeutic doses by cancer cells. Therefore, it is necessary to continuously develop more effective and selective intelligent boron delivery agents. Summary of the Invention

[0006] In view of the defects or deficiencies existing in the prior art, the present invention provides a multi-boron complex, and each molecule contains more than two 10 B atoms, which can effectively increase the 10 B uptake, and can be applied to boron neutron capture therapy. After introducing a tumor-targeting fragment, the multi-boron complex of the present invention can selectively accumulate in tumor cells, achieving the dual effects of tumor targeting and high uptake, and is expected to be further applied to boron neutron capture therapy.

[0007] Another object of the present invention is to provide a pharmaceutical composition.

[0008] Another object of the present invention is to provide a preparation method of the multi-boron complex.

[0009] Another object of the present invention is to provide the use of the multi-boron complex.

[0010] To achieve the above object, on the one hand, the present invention provides a multi-boron complex or its stereoisomer, deuterated compound or pharmaceutically acceptable salt, wherein the multi-boron complex has the following structure shown in formula (I):

[0011]

[0012] R1 and R2 are each independently selected from: H, F, Cl, Br, I, -OH, -R'OH, alkyl, alkoxy, amino, nitro, cyano, alkylthio, alkenyl, alkynyl, cycloalkyl, cycloalkyloxy, cycloalkylthio, acyl, ester, amide, aryl, heterocyclic group, heteroaryl, heterocycloalkyl, monoalkylamino or dialkylamino;

[0013] R' is selected from substituted or unsubstituted alkylene with 1 to 6 carbon atoms; the substituted group is selected from halogen, hydroxyl, amino, nitro;

[0014] R3 is -OH,

[0015] R6 is selected from a single bond, alkylene with 1 to 3 carbon atoms;

[0016] R5 is selected from H, F, Cl, Br, I, hydroxyl or dihydroxyboronyl;

[0017] a and b are each independently selected from 0, 1, 2, 3 or 4;

[0018] x is selected from 0, 1, 2, 3 or 4;

[0019] n is selected from 0, 1 or 2;

[0020] The above * is the connection site.

[0021] To achieve the above object of solving the technical problem, in the present invention, principles such as structural splicing and skeleton transition are adopted to design a multi-boron complex, which is mainly obtained through multiple steps of reactions such as Schiff base and complexation, providing a new candidate intelligent boron delivery agent for boron neutron capture therapy.

[0022] According to some specific embodiments of the present invention,

[0023] R1 and R2 are each independently selected from: H, F, Cl, Br, I, -OH, -R'OH, alkyl, alkoxy, amino, nitro, cyano, alkylthio, alkenyl, alkynyl, cycloalkyl, cycloalkyloxy, cycloalkylthio, acyl, ester, amide, aryl, heterocyclic group, heteroaryl, heterocycloalkyl, monoalkylamino or dialkylamino;

[0024] R' is selected from substituted or unsubstituted alkylene with 1 to 6 carbon atoms; the substituted groups are selected from halogen, hydroxyl, amino, nitro;

[0025] R3 is

[0026] R5 is selected from H, F, Cl, Br, I, hydroxyl or dihydroxyboron group;

[0027] a and b are each independently selected from 0, 1, 2, 3 or 4;

[0028] x is selected from 0, 1, 2, 3 or 4;

[0029] n is selected from 0, 1 or 2;

[0030] The above * is the connection site.

[0031] According to some specific embodiments of the present invention, the structure of the multi-boron complex is shown in the following formula (II):

[0032]

[0033] According to some specific embodiments of the present invention, the structure of the multi-boron complex is shown in the following formula (II-1) or (II-2):

[0034]

[0035] According to some specific embodiments of the present invention, the structure of the multi-boron complex is shown in the following formula (II-1-1) or (II-2-1):

[0036]

[0037] According to some specific embodiments of the present invention, is Preferably,

[0038] According to some specific embodiments of the present invention, wherein, is

[0039] According to some specific embodiments of the present invention, wherein, selected from R1 and R2 are each independently selected from H, methyl; preferably, R1 and R2 are each independently methyl. n is 1. a and b are each independently 0 or 1; preferably, a and b are each independently 1.

[0040] According to some specific embodiments of the present invention, wherein, R1 and R2 are each independently selected from H, F, Cl, Br, I, -OH, -R'OH, nitro, cyano, C 1-10 alkyl or C 1-10 alkoxy.

[0041] According to some specific embodiments of the present invention, wherein, R1 and R2 are each independently selected from F, Cl, Br, I, -OH, -R'OH, nitro, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, -CH(CH3)CH2CH2CH3, -CH2CH(CH3)CH2CH3, -CH2CH2CH(CH3)2, -CH(C2H5)CH2CH3, -C(CH3)2CH2CH3, -CH(CH3)CH(CH3)2, -CH2C(CH3)3, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy or tert-butoxy.

[0042] According to some specific embodiments of the present invention, wherein, R1 and R2 are each independently selected from H, F, Cl, Br, I, -OH, -R'OH, nitro, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, -CH(CH3)CH2CH2CH3, -CH2CH(CH3)CH2CH3, -CH2CH2CH(CH3)2, -CH(C2H5)CH2CH3, -C(CH3)2CH2CH3, -CH(CH3)CH(CH3)2, -CH2C(CH3)3, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy or tert-butoxy.

[0043] According to some specific embodiments of the present invention, wherein, the -R'OH is independently selected from: -CH2OH, -CH2CH2OH, -CH(OH)CH2OH, -CHFCH2OH, -CHClCH2OH, -CHFCHClOH, -CHBrCH2OH, -CHICH2OH, -CH(NH2)CH2OH, -CH(NO2)CH2OH, -CH(OH)CH2OH, -(CH2)3OH, -CHFCH2CH2OH, -CHFCH(OH)CH2OH, -CHClCH2CH2OH, -CH(OH)CH(OH)CH2OH, -CHFCHFCH2OH, -CH(CH2OH)CH2OH, -(CH2)4OH, -CH(OH)(CH2)3OH, -CHF(CH2)3OH, -CH(CH2OH)CH2CH2OH, -(CH2)5OH, -CH(OH)(CH2)4OH, -CHCl(CH2)4OH, -CHF(CH2)4OH, -CHBr(CH2)4OH, -CH(OH)CH(CH2OH)CH2CH2OH, -CH(OH)CH(OH)CH2CH2CH2OH, -CH(OH)CH(OH)CH2CH(OH)CH2OH, -CH(CH2OH)CH(CH2OH)CH2OH, -(CH2)6OH, -CH(OH)CH(OH)CH2CH2CH2CH2OH, -CH(OH)(CH2)5OH, -CHF(CH2)5OH, -CH(OH)CH(CH2OH)CH2CH2CH2OH, -CH(CH2OH)CH(CH2OH)CH2CH2OH.

[0044] According to some specific embodiments of the present invention, wherein, R1 and R2 are each independently selected from F, Cl, Br, I, -OH, -R'OH, methyl, methoxy or ethoxy.

[0045] According to some specific embodiments of the present invention, wherein, R1 and R2 are each independently selected from H, F, Cl, Br, I, -OH, -R'OH, C 1-3 alkyl or C 1-3 alkoxy.

[0046] According to some specific embodiments of the present invention, wherein, R5 is selected from H, F, Cl, Br, I or hydroxyl; preferably H. x is selected from 0, 1, 2, 3 or 4; preferably 0 or 1.

[0047] According to some specific embodiments of the present invention, R1 and R2 are each independently selected from H, F, Cl, Br, I, -OH, -R'OH, methyl, methoxy or ethoxy; R' is selected from substituted or unsubstituted alkylene with 1 to 3 carbon atoms; the substituted group is selected from halogen and hydroxyl;

[0048] R5 is selected from H, F, Cl, Br, I, and hydroxyl;

[0049] a and b are each independently selected from 0, 1 or 2;

[0050] x is selected from 0, 1, 2, 3 or 4;

[0051] n is selected from 0, 1 or 2.

[0052] According to some specific embodiments of the present invention, R1 and R2 are each independently selected from F, Cl, Br, I, -OH, -R'OH, methoxy or ethoxy;

[0053] R5 is selected from H, F, Cl, Br or I;

[0054] a and b are each independently selected from 1 or 2;

[0055] x is 0, 1 or 2; preferably 0;

[0056] n is 1.

[0057] According to some specific embodiments of the present invention, R1 and R2 are each independently selected from F, Cl, Br, I or -OH;

[0058] R5 is selected from H, F, Cl, Br or I;

[0059] a and b are each independently selected from 1 or 2;

[0060] x is 0 or 1; preferably 0;

[0061] n is 1.

[0062] According to some specific embodiments of the present invention, R1 and R2 are each independently selected from hydrogen, nitro, cyano, methyl;

[0063] R5 is selected from H, F, Cl, Br or I; preferably H;

[0064] a and b are each independently selected from 1 or 2;

[0065] x is 0, 1 or 2; preferably 0;

[0066] n is 1.

[0067] According to some specific embodiments of the present invention, R1 and R2 are the same, a and b are the same, and R1 and R2 are symmetric about the axis A-A' of the following formula (I) on the left and right:

[0068]

[0069] It can be understood that in formula (II), R1 and R2 can also be the same, a and b are the same, and R1 and R2 are symmetric about the axis A-A' similar to that in formula (I) on the left and right.

[0070] According to some specific embodiments of the present invention, the polyboron complex is selected from one of the following structures:

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] According to some specific embodiments of the present invention, the polyboron complex is selected from one of the following structures:

[0080]

[0081] According to some specific embodiments of the present invention, the polyboron complex is selected from one of the following structures:

[0082]

[0083]

[0084] According to some specific embodiments of the present invention, the polyboron complex is selected from one of the following structures:

[0085]

[0086] According to some specific embodiments of the present invention, at least one of the Bs in the polyboron complex is 10 B.

[0087] According to some specific embodiments of the present invention, all B of the multi-boron complex is 10 B.

[0088] On the other hand, the present invention also provides a method for preparing the multi-boron complex or its stereoisomers, deuterated compounds or pharmaceutically acceptable salts, wherein the method includes the step of preparing the multi-boron complex from compound (1) and compound (2) as raw materials:

[0089]

[0090] R1 and R2 are each independently selected from: H, F, Cl, Br, I, -OH, -R'OH, alkyl, alkoxy, amino, nitro, cyano, alkylthio, alkenyl, alkynyl, cycloalkyl, cycloalkyloxy, cycloalkylthio, acyl, ester, amide, aryl, heterocyclic group, heteroaryl, heterocycloalkyl, monoalkylamino or dialkylamino; R' is selected from substituted or unsubstituted alkylene with 1 to 6 carbon atoms; the substituted groups are selected from halogen, hydroxyl, amino, nitro;

[0091] R3 is R5 is selected from H, F, Cl, Br, I, hydroxyl or dihydroxyboronyl; x is selected from 0, 1, 2, 3 or 4;

[0092] a and b are each independently selected from 0, 1, 2, 3 or 4;

[0093] n is selected from 0, 1 or 2;

[0094] The above * is the connection site.

[0095] In some embodiments, is

[0096] In some embodiments, compound (2) is R5 and x are as described above. Further, compound (2) can be i.e., BPA (p-boronophenylalanine); compound (2) can be i.e., 3-BPA (m-boronophenylalanine); compound (2) can also be i.e., 2-BPA (o-boronophenylalanine).

[0097] In the examples of the present invention, compound (2) in the preparation of the multi-boron complex uses BPA (p-boronophenylalanine), and the number of this multi-boron complex contains "BNC-4", which can be seen in the numbering of the compounds in the examples; compound (2) in the preparation of the multi-boron complex uses 3-BPA (m-boronophenylalanine), and the number of this multi-boron complex contains "BNC-3", which can be seen in the numbering of the compounds in the examples.

[0098] In some embodiments, the method includes: reacting compound (1) with compound (2) at 80 to 100 °C.

[0099] In some embodiments, the method includes: reacting compound (1) with compound (2) at 80 to 100 °C for 18 to 30 hours.

[0100] The reaction solvent for compound (1) and compound (2) is selected from at least one of acetonitrile, dichloroethane, N,N-dimethylformamide, and dimethyl sulfoxide. The molar ratio of compound (1) to compound (2) is 1:1.

[0101] According to some specific embodiments of the present invention, wherein the method further includes a step of preparing compound (1) using the compound of formula (3) and boric acid as raw materials:

[0102] wherein R1, R2, a, b, and n are as defined above.

[0103] Furthermore, in some embodiments, the method includes: adding boric acid to the compound of formula (3) in an organic solvent, and reacting under the protection of an inert gas to obtain a polyboron complex. The reaction temperature is 80 to 100 °C.

[0104] In some embodiments, the reaction time is 3 to 5 hours.

[0105] The organic solvent is selected from at least one of acetonitrile, dichloroethane, N,N-dimethylformamide, and dimethyl sulfoxide. The molar ratio of the compound of formula (3) to boric acid is 1:2.

[0106] According to some specific embodiments of the present invention, wherein the method further includes a step of preparing the compound of formula (3) using the compound of formula (4), the compound of formula (4'), and the compound of formula (5) as raw materials:

[0107] wherein R1, R2, a, b, and n are as defined above.

[0108] Furthermore, in some embodiments, the method includes: dissolving the compound of formula (4) and the compound of formula (4') in ethanol, adding ethylenediamine, reacting for 18 to 30 hours, adjusting the temperature of the reaction solution to 0 to 10 °C after the reaction, and filtering to obtain the compound of formula (3).

[0109] In some embodiments, the molar ratio of the compound of formula (4 / 4') to the compound of formula (5) is 2:1. That is, the sum of the compound of formula (4) and the compound of formula (4') and the compound of formula (5) has a molar ratio of 2:1.

[0110] According to some specific embodiments of the present invention, the structures of the compound of formula (4) and the compound of formula (4') are the same.

[0111] According to some specific embodiments of the present invention, the structures of the compound of formula (4) and the compound of formula (4') are different.

[0112] It can be imagined that when the structures of the compound of formula (4) and the compound of formula (4') are the same, the raw materials used are more single and easier to obtain, and the products are also more single. In addition, when the structures of the compound of formula (4) and the compound of formula (4') are different, the various products prepared are all the multi-boron complexes of the present invention.

[0113] According to some specific embodiments of the present invention, the compound of formula (4) and the compound of formula (4') are each independently selected from one of the following compounds:

[0114]

[0115]

[0116] On the other hand, the present invention also provides a pharmaceutical composition, wherein the pharmaceutical composition contains the multi-boron complex or its stereoisomer, deuterated compound or pharmaceutically acceptable salt described in any one of the present invention, and a pharmaceutically acceptable carrier.

[0117] According to some specific embodiments of the present invention, the pharmaceutical composition further includes a cosolvent. Further, the cosolvent includes galactose or fructose. The cosolvent can be prepared with a phosphate buffer of NaOH.

[0118] According to some specific embodiments of the present invention, the pharmaceutical composition further contains galactose. Based on the total weight of the pharmaceutical composition being 100%, the weight percentage of the multi-boron complex or its stereoisomer, deuterated compound or pharmaceutically acceptable salt is 0.05% - 90%, and the weight percentage of galactose is 40% - 60%.

[0119] According to some specific embodiments of the present invention, the pharmaceutical composition further contains galactose. Based on the total weight of the pharmaceutical composition being 100%, the weight percentage of the multi-boron complex or its stereoisomer, deuterated compound or pharmaceutically acceptable salt is 0.05% - 90%, and the weight percentage of galactose is 40% or 50% or 60%.

[0120] According to some specific embodiments of the present invention, the weight percentage of the multi-boron complex or its stereoisomer, deuterated compound or pharmaceutically acceptable salt is 50% - 90%.

[0121] According to some specific embodiments of the present invention, the method for preparing the pharmaceutical composition includes: preparing a multi-boron complex composition using a phosphate buffer solution of NaOH.

[0122] In another aspect, the present invention also provides the use of the aforementioned multi-boron complex or its stereoisomers, deuterated compounds, or pharmaceutically acceptable salts, or the pharmaceutical composition of the present invention in the preparation of anti-tumor drugs.

[0123] According to some specific embodiments of the present invention, the tumor can be glioblastoma, pancreatic cancer, triple-negative breast cancer, liver cancer, melanoma, head and neck tumors, brain tumors, meningiomas, pleural mesotheliomas, lung cancer, osteosarcoma, cervical cancer, or bladder cancer.

[0124] According to some specific embodiments of the present invention, the tumor is a central nervous system tumor or breast cancer.

[0125] In some embodiments, the tumor can also be other cancer types suitable for BNCT drugs (such as BPA).

[0126] According to some specific embodiments of the present invention, the anti-tumor drug is an anti-tumor drug used under neutron irradiation conditions.

[0127] According to some specific embodiments of the present invention, the anti-tumor drug is a drug for boron neutron capture therapy.

[0128] In summary, the present invention provides a multi-boron complex and its preparation and application.

[0129] The multi-boron complex of the present invention has the following advantages:

[0130] The present invention provides a new multi-boron complex. Starting from existing raw materials, the reagents used are inexpensive and easily available, the operation is simple, and it is easy to prepare. The synthesis method of the present invention has the characteristics of mild reaction conditions, high yield, economy and practicality. The compound of the present invention and its synthesis method are reported for the first time in the present invention.

[0131] The multi-boron complex described in the present invention has low biological toxicity. The multi-boron complex described in the present invention has a high T / B ratio and boron enrichment amount in tumor cells.

[0132] The present invention can be used as a boron drug for BNCT and has excellent application prospects in the field of anti-tumor. BRIEF DESCRIPTION OF THE DRAWINGS

[0133] Figures 1 to 9 It is the result of the cytotoxicity experiment in Test Example 1.

[0134] Figures 10 to 13 It is the data graph for evaluating the boron uptake ability in Test Example 2.

[0135] Figures 14 to 16 It is a graph of in vitro activity evaluation data for Application Example 1.

[0136] Figure 17 It is the ultraviolet determination result of Test Example 3.

[0137] Figure 18 and Figure 19 It is the fluorescence determination result of Test Example 4.

[0138] Figures 20 to 23 It is the cell safety determination result of Test Example 5.

[0139] Figure 24 and Figure 25 It is the cell uptake experiment result of Test Example 6.

[0140] Figure 26 and Figure 27 It is the BNCT treatment effect result of Application Example 2.

[0141] Figure 28 and Figure 29 It is the in vivo boron distribution research result of Application Example 3. Detailed implementation manners

[0142] The implementation process and beneficial effects of the present invention are described in detail below through specific examples, aiming to help readers better understand the essence and characteristics of the present invention, and shall not be construed as a limitation on the scope of implementation of this case.

[0143] Unless otherwise defined, all scientific and technical terms herein have the same meaning as commonly understood by those skilled in the art to which the claimed subject matter pertains. It should be understood that the foregoing summary and the following detailed description are exemplary and explanatory only and do not limit the subject matter of the present invention. In this application, unless otherwise specifically stated, the use of the singular also includes the plural. It must be noted that, unless clearly stated otherwise in the text, the singular forms used in this specification and the claims include the plural forms of the referred objects. It should also be noted that, unless otherwise stated, the terms "or" and "or" mean "and / or". In addition, the terms "comprising" and other forms, such as "including", "containing", and "having" are not restrictive.

[0144] Except as described above, when used in the specification and claims of this application, unless otherwise specifically indicated, the following terms have the meanings shown below.

[0145] The term "alkenyl" means an unbranched or branched monovalent hydrocarbon chain containing one or more carbon-carbon double bonds, including but not limited to C2-3 alkenyl, C2-4 alkenyl, or C2-5 alkenyl.

[0146] The term "alkynyl" refers to a straight-chain or branched monovalent hydrocarbon chain containing one or more carbon-carbon triple bonds, including but not limited to C2-3 alkynyl, C2-4 alkynyl, or C2-5 alkynyl.

[0147] The term "cycloalkyl" or "carbocyclic group" refers to an alkyl group that is cyclic and contains 3 to 15, 3 to 9, 3 to 6, or 3 to 5 carbon atoms, with alternating or resonating double bonds between the carbon atoms. It may contain 1 to 4 rings. Examples of unsubstituted cycloalkyl groups include but are not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and adamantyl. The cycloalkyl group can be substituted with one or more substituents. In some embodiments, the cycloalkyl group can be a cycloalkyl group fused to an aryl or heteroaryl group.

[0148] The term "heterocycloalkyl" or "heterocyclic group" refers to a cycloalkyl group in which one or more, in some embodiments, 1 to 3 carbon atoms are replaced by heteroatoms such as but not limited to N, O, or S. In some embodiments, the heterocycloalkyl group contains 3 to 15, 3 to 9, 3 to 6, or 3 to 5 carbon and heteroatoms. In some embodiments, the heterocycloalkyl group can be a heterocycloalkyl group fused to an aryl or heteroaryl group. When a prefix such as C3-6 is used to denote a heterocycloalkyl group, the number of carbons (in this instance 3-6) also means including the heteroatoms. For example, C3-6 heterocycloalkyl means including, for example, tetrahydropyranyl (five carbon atoms and one heteroatom replacing a carbon atom).

[0149] The term "aryl" refers to a carbocyclic aromatic ring containing 5 to 14 ring atoms. All the ring atoms of the carbocyclic aryl group are carbon atoms. The aryl ring structure includes compounds having one or more ring structures, such as monocyclic, bicyclic, or tricyclic compounds, as well as benzo-fused carbocyclic moieties such as 5,6,7,8-tetrahydronaphthyl, etc. Specifically, the aryl group can be monocyclic, bicyclic, or tricyclic. Representative aryl groups include phenyl, anthracenyl, fluorenyl, indenyl, phenanthryl, and naphthyl.

[0150] The term "heteroaryl" refers to a monocyclic or polycyclic aromatic ring system in which, in certain embodiments, 1 to 3 atoms in the ring system are heteroatoms, i.e., elements other than carbon, including but not limited to N, O, or S. The heteroaryl group can be optionally fused to a benzene ring. Heteroaryl groups include but are not limited to furyl, imidazolyl, dihydroindolyl, pyrrolidinyl, pyrimidinyl, tetrazolyl, thienyl, pyridyl, pyrrolyl, N-methylpyrrolyl, quinolinyl, and isoquinolinyl.

[0151] The term "stereoisomer" refers to isomers resulting from different spatial arrangements of atoms in a molecule, including but not limited to cis-trans isomers, enantiomers, and diastereomers.

[0152] The present invention is further illustrated below in conjunction with specific embodiments.

[0153] Example 1

[0154] This embodiment provides a multi-boron complex (Compound A), whose structure is shown as follows:

[0155]

[0156] The preparation method of Compound A includes the following steps:

[0157]

[0158] (1) Dissolve 2,4-dihydroxybenzaldehyde (1a, 1.38 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), reflux for 18 - 30 h. Monitor the reaction by TLC until it is completed. Cool the reaction solution to 0 - 10 °C, and filter it under vacuum with a pump to obtain 1.52 g of yellow solid, getting Compound 2a with a yield of 96.8%.

[0159] (2) Dissolve Compound 2a (314 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 61 mg of boric acid ( 10 B, 1 mmol), and heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until it is completed. Cool the reaction solution and perform recrystallization to obtain 323 mg of the product with a yield of 78.8%.

[0160] The spectral data of the product is: ESI-MS (m / z): 408 [M + H] + ;

[0161] 1 1H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.27 (d, J = 8.6 Hz, 2H), 6.32 (dd, J = 8.5, 2.2 Hz, 2H), 6.19 (d, J = 2.1 Hz, 2H), 3.84–3.57 (m, 4H), 2.89 (s, 1H), 2.73 (s, 1H), 2.44–2.30 (m, 1H), 1.96–1.90 (m, 1H).

[0162] Example 2

[0163] This embodiment provides a multi-boron complex, whose structure is shown as follows:

[0164]

[0165] Referring to the synthesis method in Example 1, from p-hydroxyphenylboronic acid ( 10B) Instead of boric acid in the alternative method, a pale yellow solid product was finally obtained with a yield of 80.4%.

[0166] The product spectrum data was: ESI-MS (m / z): 484 [M+H] + ;

[0167] 1 1H NMR (500 MHz, DMSO-d6) δ 8.49–8.32 (m, 2H), 7.45–7.12 (m, 4H), 6.52–6.05 (m, 6H), 3.84–3.54 (m, 4H), 2.09 (s, 2H).

[0168] Example 3

[0169] This example provides a multi-boron complex with the following structure:

[0170]

[0171] Referring to the synthesis method in Example 1, 4-hydroxymethylphenylboronic acid ( 10 B) was used instead of boric acid in the method, and finally a pale yellow solid product was obtained with a yield of 82.1%.

[0172] The product spectrum data was: ESI-MS (m / z): 498 [M+H] + ;

[0173] 1 1H NMR (500 MHz, DMSO-d6) δ 8.52–8.34 (m, 2H), 7.49–7.10 (m, 4H), 6.50–6.08 (m, 6H), 3.90–3.48 (m, 6H), 2.03–1.92 (m, 2H).

[0174] Example 4

[0175] This example provides a multi-boron complex (4OH-BNC-4) with the following structure:

[0176]

[0177] The preparation method of the multi-boron complex (4OH-BNC-4) in this example includes the following steps:

[0178]

[0179] (1) Dissolve 2,4-dihydroxybenzaldehyde (1a, 1.38 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), and reflux for 18 - 30 h. Monitor the reaction by TLC until it is completed. Cool the reaction solution to 0 - 10 °C and filter it under vacuum with a pump to obtain 1.52 g of yellow solid, yielding compound 2a with a yield of 96.8%.

[0180] (2) Dissolve compound 2a (314 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., and then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h. Then add 209 mg of 4-borono-L-phenylalanine ( 10 B, 1 mmol), and heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until it is completed. Cool the reaction solution and recrystallize to obtain 462 mg of 4OH-BNC-4 with a yield of 82.9%.

[0181] The spectral data of 4OH-BNC-4 are as follows: ESI-MS (m / z): 555 [M + H] + ; 1 1H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.27 (d, J = 8.6 Hz, 4H), 6.43–6.09 (m, 6H), 3.69 (dt, J = 20.7, 10.1 Hz, 6H), 2.89 (s, 2H), 2.73 (d, J = 0.6 Hz, 2H), 2.35 (d, J = 8.1 Hz, 1H), 2.14–1.85 (m, 2H).

[0182] Example 5

[0183] This example provides a multi-boron complex, the structure of which is shown as follows:

[0184]

[0185] The preparation method of the compound in this example includes the following steps:

[0186]

[0187] Referring to the synthesis method in Example 1, replace (1a) in the method with 2,5-dihydroxybenzaldehyde (1b), and finally obtain a yellow solid (2b) with a yield of 97.1%.

[0188] Referring to the synthesis method in Example 1, replace (2a) in the method with (2b), and use 4-borono-L-phenylalanine ( 10B) Instead of boric acid in the alternative method, a pale yellow solid product was finally obtained with a yield of 79.7%.

[0189] The product spectral data were: ESI-MS (m / z): 555 [M+H] + ;

[0190] 1 1H NMR (300 MHz, DMSO-d6) δ 8.38 (s, 2H), 7.28 (s, 4H), 6.45–6.11 (m, 6H), 3.72–3.42 (m, 6H), 2.90 (s, 2H), 2.74 (s, 2H), 2.36 (s, 1H), 2.12–1.88 (m, 2H).

[0191] Example 6

[0192] This example provides a multi-boron complex, the structure of which is shown as follows:

[0193]

[0194] The preparation method of the multi-boron complex in this example includes the following steps:

[0195]

[0196] Referring to the synthesis method in Example 1, 2,4,5-trihydroxybenzaldehyde (1c) was used instead of (1a) in the method, and finally a yellow solid (2c) was obtained with a yield of 96.5%.

[0197] Referring to the synthesis method in Example 1, (2c) was used instead of (2a) in the method, and 4-borono-L-phenylalanine ( 10 B) was used instead of boric acid in the method, and finally a pale yellow solid product was obtained with a yield of 76.1%.

[0198] The product spectral data were: ESI-MS (m / z): 587 [M+H] + ;

[0199] 1 1H NMR (500 MHz, DMSO-d6) δ 8.38 (s, 1H), 7.29 (s, 4H), 6.45–6.11 (m, 5H), 3.71–3.41 (m, 6H), 2.91 (s, 2H), 2.72 (s, 2H), 2.35 (s, 1H), 2.11–1.86 (m, 2H).

[0200] Example 7

[0201] This example provides a multi-boron complex, the structure of which is shown as follows:

[0202]

[0203] The preparation method of the multi-boron complex comprises the following steps:

[0204]

[0205] Referring to the synthesis method in Example 1, 2-hydroxy-5-hydroxymethylbenzaldehyde (1d) is used to replace (1a) in the method, and finally a yellow solid (2d) is obtained with a yield of 92.5%.

[0206] Referring to the synthesis method in Example 1, (2d) is used to replace (2a) in the method, and 4-boronic acid-L-phenylalanine ( 10 B) is used to replace boric acid in the method, and finally a pale yellow solid product is obtained with a yield of 72.0%.

[0207] The product spectrum data are: ESI-MS (m / z): 583 [M+H] + ;

[0208] 1 1H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.26 (s, 4H), 6.46–6.10 (m, 6H), 3.85–3.34 (m, 10H), 2.91 (s, 2H), 2.73 (s, 2H), 2.35 (s, 1H), 2.10–1.85 (m, 2H).

[0209] Example 8

[0210] This example provides a multi-boron complex (4F-BNC-4), and its structure is shown as follows:

[0211]

[0212] The preparation method of the multi-boron complex (4F-BNC-4) in this example comprises the following steps:

[0213]

[0214] Referring to the synthesis method in Example 1, 2-hydroxy-4-fluorobenzaldehyde (1e) is used to replace (1a) in the method, and finally a yellow solid (2e) is obtained with a yield of 95.9%.

[0215] Referring to the synthesis method in Example 1, (2e) is used to replace (2a) in the method, and 4-boronic acid-L-phenylalanine ( 10 B) is used to replace boric acid in the method, and finally a pale yellow solid (4F-BNC-4) is obtained with a yield of 83.4%.

[0216] The spectral data of 4F-BNC-4 are: ESI-MS (m / z): 559 [M+H] + ;

[0217] 1 H NMR (300 MHz, DMSO-d6) δ 8.37 (s, 2H), 7.26 (s, 4H), 6.46–6.14 (m, 6H), 3.74–3.46 (m, 6H), 2.92 (s, 2H), 2.76 (s, 2H), 2.36 (s, 1H), 2.11–1.89 (m, 2H).

[0218] Example 9

[0219] This example provides a multi-boron complex (4Br-BNC-4), and its structure is shown as follows:

[0220]

[0221] The preparation method of the multi-boron complex (4Br-BNC-4) in this example includes the following steps:

[0222] Referring to the synthesis method in Example 1, 2-hydroxy-4-bromobenzaldehyde (1f) is used instead of (1a) in the method, and finally a yellow solid (2f) is obtained with a yield of 98.0%.

[0223] Referring to the synthesis method in Example 1, (2f) is used instead of (2a) in the method, and 4-boronic acid-L-phenylalanine ( 10 B) is used instead of boric acid in the method, and finally a light yellow solid (4Br-BNC-4) is obtained with a yield of 76.7%.

[0224] The spectral data of 4Br-BNC-4 are: ESI-MS (m / z): 679 [M+H] + ;

[0225] 1 H NMR (300 MHz, DMSO-d6) δ 8.37 (s, 2H), 7.27 (s, 4H), 6.42–6.08 (m, 6H), 3.70–3.42 (m, 6H), 2.88 (s, 2H), 2.72 (s, 2H), 2.35 (s, 1H), 2.11–1.87 (m, 2H).

[0226] Example 10

[0227] This example provides a multi-boron complex (4OH-BNC-3), which is synthesized by referring to the steps of the above examples, and its structure is as follows:

[0228]

[0229] Referring to the synthesis method in Example 4, a yellow solid (2a) was obtained with a yield of 98.0%.

[0230] Referring to the synthesis method in Example 4, using 3-boronic acid-L-phenylalanine ( 10 B) to replace boric acid in the method, and finally 445 mg of a pale yellow solid (4OH-BNC-3) was obtained with a yield of 79%.

[0231] The spectral data of 4OH-BNC-3 are: ESI-MS (m / z): 555 [M+H] + ;

[0232] 1 1H NMR (300 MHz, DMSO-d6) δ 8.37 (s, 2H), 7.27 (s, 4H), 6.42–6.08 (m, 6H), 3.70–3.42 (m, 6H), 2.92 (s, 2H), 2.93 (s, 2H), 2.35 (s, 1H), 2.11–1.87 (m, 2H).

[0233] Example 11

[0234] This example provides a multi-boron complex (4F-BNC-3), which was synthesized by referring to the steps of the above examples, and its structure is as follows:

[0235]

[0236] Referring to the synthesis method in Example 4, using 2-hydroxy-4-fluorobenzaldehyde (1e) to replace (1a) in the method, and finally a yellow solid (2e) was obtained with a yield of 95.9%.

[0237] Referring to the synthesis method in Example 4, using (2e) to replace (2a) in the method, and using 3-boronic acid-L-phenylalanine ( 10 B) to replace boric acid in the method, and finally a pale yellow solid (4F-BNC-3) was obtained with a yield of 80.4%.

[0238] The spectral data of 4F-BNC-3 are: ESI-MS (m / z): 559 [M+H] + ;

[0239] 1 1H NMR (300 MHz, DMSO-d6) δ 8.37 (s, 2H), 8.26 (s, 4H), 7.46–6.14 (m, 6H), 3.74–3.41 (m, 6H), 2.92 (s, 2H), 2.76 (s, 2H), 2.36 (s, 1H), 2.11–1.89 (m, 2H).

[0240] Example 12

[0241] This example provides a multi-boron complex (4H-BNC-4), which is synthesized by referring to the steps of the above example, and its structure is as follows:

[0242]

[0243] Referring to the synthesis method in Example 4, 2-hydroxybenzaldehyde (1 g) is used instead of (1a) in the method, and finally a yellow solid (2 g) is obtained with a yield of 98.0%.

[0244] Referring to the synthesis method in Example 4, (2 g) is used instead of (2a) in the method, and 4-boronic acid-L-phenylalanine ( 10 B) is used instead of boric acid in the method, and finally a light yellow solid (4H-BNC-4) is obtained with a yield of 78.7%.

[0245] The spectral data of 4H-BNC-4 are: ESI-MS (m / z): 524 [M+H] + ;

[0246] 1 1H NMR (300 MHz, DMSO-d6) δ 8.37 (s, 2H), 7.27 (s, 4H), 6.42–6.08 (m, 6H), 3.87–3.42 (m, 6H), 2.95 (s, 2H), 2.72 (s, 2H), 2.35 (s, 1H), 2.11–1.87 (m, 2H).

[0247] Example 13

[0248] This example provides a multi-boron complex (4H-BNC-3), which is synthesized by referring to the steps of the above example, and its structure is as follows:

[0249]

[0250] Referring to the synthesis method in Example 4, 2-hydroxybenzaldehyde (1 g) is used instead of (1a) in the method, and finally a yellow solid (2 g) is obtained with a yield of 98.0%.

[0251] Referring to the synthesis method in Example 4, (2 g) is used instead of (2a) in the method, and 3-boronic acid-L-phenylalanine ( 10 B) is used instead of boric acid in the method, and finally a light yellow solid (4H-BNC-3) is obtained with a yield of 75.6%.

[0252] The spectral data of 4H-BNC-3 are: ESI-MS (m / z): 524 [M+H] + ;

[0253] 1 1H NMR (300 MHz, DMSO-d6) δ 8.37 (s, 2H), 7.27 (s, 4H), 6.42–6.08 (m, 6H), 3.97–3.42 (m, 6H), 2.75 (s, 2H), 2.62 (s, 2H), 2.35 (s, 1H), 2.11–1.87 (m, 2H).

[0254] Example 14

[0255] This example provides a multi-boron complex with the following structure:

[0256]

[0257] Synthesized by referring to the steps of the above examples, the synthesis route is as follows:

[0258]

[0259] Referring to the synthesis method in Example 4, 1,2-ethylenediamine was used instead of 1,2-propanediamine in the method, and finally a yellow solid (2h) was obtained with a yield of 95.0%.

[0260] Referring to the synthesis method in Example 4, (2h) was used instead of (2a) in the method, and 4-boronic acid-L-phenylalanine ( 10 B) was used instead of boric acid in the method, and finally a light yellow solid product was obtained with a yield of 78.6%.

[0261] Product spectral data: ESI-MS (m / z): 542 [M+H] + ;

[0262] 1 1H NMR (300 MHz, DMSO-d6) δ 9.37 (s, 2H), 7.87 (s, 4H), 6.82–6.08 (m, 6H), 4.97–3.42 (m, 6H), 3.75 (s, 2H), 2.62 (s, 2H), 2.35 (s, 1H), 2.11–1.87 (m, 2H).

[0263] Example 15

[0264] This example provides a multi-boron complex, synthesized by referring to the steps of the above examples, with the following structure:

[0265]

[0266] Referring to the synthesis method in Example 4, 1,2-ethylenediamine was used instead of 1,2-propanediamine in the method, and finally a yellow solid (2h) was obtained with a yield of 95.0%.

[0267] Referring to the synthesis method in Example 4, replace (2a) in the method with (2h), and replace boric acid in the method with 3-boronic acid-L-phenylalanine ( 10 B), and finally obtain a pale yellow solid product with a yield of 79.6%.

[0268] The product spectrum data is: ESI-MS (m / z): 542 [M+H] + ;

[0269] 1 1H NMR (300 MHz, DMSO-d6) δ 9.37 (s, 2H), 7.87 (s, 4H), 6.72–6.08 (m, 6H), 4.97–3.32 (m, 6H), 3.65 (s, 2H), 2.62 (s, 2H), 2.35 (s, 1H), 2.11–1.87 (m, 2H).

[0270] Example 16

[0271] This example provides a multi-boron complex with the following structure:

[0272]

[0273] Synthesize by referring to the steps of the above examples, and the synthesis route is as follows:

[0274]

[0275] Referring to the synthesis method in Example 4, replace 1,2-propanediamine in the method with 1,4-butanediamine, and finally obtain a yellow solid (2i) with a yield of 92.0%.

[0276] Referring to the synthesis method in Example 4, replace (2a) in the method with (2i), and replace boric acid in the method with 4-boronic acid-L-phenylalanine ( 10 B), and finally obtain a pale yellow solid product with a yield of 73.6%.

[0277] The product spectrum data is: ESI-MS (m / z): 570 [M+H] + ;

[0278] 1 1H NMR (300 MHz, DMSO-d6) δ 9.37 (s, 2H), 8.87 (s, 4H), 7.82–5.08 (m, 6H), 4.97–4.42 (m, 6H), 3.75 (s, 2H), 2.62 (s, 2H), 2.35 (s, 1H), 2.11–1.87 (m, 2H).

[0279] Example 17

[0280] This example provides a multi-boron complex, which is synthesized according to the steps of the above-mentioned example, and its structure is as follows:

[0281]

[0282] Referring to the synthesis method in Example 4, 1,4-diaminobutane is used instead of 1,2-propanediamine in the method, and finally a yellow solid (2i) is obtained with a yield of 92.0%.

[0283] Referring to the synthesis method in Example 4, (2i) is used instead of (2a) in the method, and 3-borono-L-phenylalanine ( 10 B) is used instead of boric acid in the method, and finally a pale yellow solid product is obtained with a yield of 68.6%.

[0284] The product spectrum data is: ESI-MS (m / z): 570 [M+H] + ;

[0285] 1 1H NMR (300 MHz, DMSO-d6) δ 9.37 (s, 2H), 7.87 (s, 4H), 6.82–5.08 (m, 6H), 4.97–342 (m, 6H), 2.75 (s, 2H), 2.62 (s, 2H), 2.35 (s, 1H), 2.11–1.87 (m, 2H).

[0286] Example 18

[0287] This example provides a multi-boron complex (4-Me-BNC-4 or 4CH3-BNC-4), the structure of which is shown below, and its preparation method includes the following steps:

[0288]

[0289] (1) Dissolve 2,4-dihydroxybenzaldehyde (1j, 1.36 g, 10 mmol) in 80 - 200 mL of ethanol, then add propanediamine (0.37 g, 5 mmol), reflux for 18 - 30 h, monitor the reaction by TLC until completion, cool the reaction solution to 0 - 10 °C, and filter it under vacuum to obtain 1.51 g of yellow solid, obtaining compound 2j with a yield of 97.4%.

[0290] (2) Dissolve compound 2j (316 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol), under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, and then add 209 mg of 4-borono-L-phenylalanine ( 10B, 1 mmol), heated under reflux at 80 - 100 °C for 18 - 30 h. After monitoring the reaction by TLC until completion, the reaction solution was cooled, and recrystallization gave 473 mg of 4-Me-BNC-4 (4CH3-BNC-4) with a yield of 85.5%.

[0291] The spectral data of 4-Me-BNC-4 are as follows: ESI-MS (m / z): 553 [M+H] + ;

[0292] 1 1H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.22 (d, J = 8.6 Hz, 4H), 6.43–6.19 (m, 6H), 3.59 (dt, J = 20.7, 10.1 Hz, 6H), 2.84 (s, 2H), 2.73 (d, J = 0.6 Hz, 2H), 2.32 (d, J = 8.1 Hz, 1H), 2.14–1.85 (m, 2H).

[0293] Example 19

[0294] This example provides a multi-boron complex (4-Me-BNC-3 or 4CH3-BNC-3), whose structure is shown below. Its preparation method includes the following steps:

[0295]

[0296] (1) Dissolve 2,4-dihydroxybenzaldehyde (1j, 1.36 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), and reflux for 18 - 30 h. After monitoring the reaction by TLC until completion, the reaction solution was cooled to 0 - 10 °C, and filtered with a vacuum pump to obtain 1.51 g of a yellow solid, giving compound 2j with a yield of 97.4%.

[0297] (2) Dissolve compound 2j (316 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat under reflux at 80 - 100 °C for 4 h, then add 209 mg of 3-borono-L-phenylalanine ( 10 B, 1 mmol), heat under reflux at 80 - 100 °C for 18 - 30 h. After monitoring the reaction by TLC until completion, the reaction solution was cooled, and recrystallization gave 475 mg of 4-Me-BNC-3 (4CH3-BNC-3) with a yield of 85.9%.

[0298] The spectral data of 4-Me-BNC-3 are as follows: ESI-MS (m / z): 553 [M+H] + ;

[0299] 1 1H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.21 (d, J = 8.6 Hz, 4H), 6.43–6.18 (m, 6H), 3.56 (dt, J = 20.7, 10.1 Hz, 6H), 2.82 (s, 2H), 2.73 (d, J = 0.6 Hz, 2H), 2.3 (d, J = 8.1 Hz, 1H), 2.14–1.85 (m, 2H).

[0300] Example 20

[0301] This example provides a multi-boron complex (4Cl-BNC-4), whose structure is shown below. Its preparation method includes the following steps:

[0302]

[0303] (1) Dissolve 4-chloro-2-hydroxybenzaldehyde (1k, 1.56 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), reflux for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution to 0 - 10 °C and filter it with a vacuum pump to obtain 1.51 g of yellow solid, getting compound 2k with a yield of 86%.

[0304] (2) Dissolve compound 2k (351 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 209 mg of 4-borono-L-phenylalanine ( 10 B, 1 mmol), heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution and recrystallize to obtain 474 mg of 4-Cl-BNC-4 with a yield of 79.8%.

[0305] The spectral data of 4-Cl-BNC-4 is: ESI-MS (m / z): 593 [M + H] + ;

[0306] 11H NMR (300 MHz, DMSO-d6) δ 8.34 (s, 2H), 7.2 (d, J = 8.6 Hz, 4H), 6.42–6.19 (m, 6H), 3.59 (dt, J = 20.7, 10.1 Hz, 6H), 2.84 (s, 2H), 2.73 (d, J = 0.6 Hz, 2H), 2.31 (d, J = 8.1 Hz, 1H), 2.14–1.85 (m, 2H).

[0307] Example 21

[0308] This example provides a multi-boron complex (4Cl-BNC-3), whose structure is shown below. Its preparation method includes the following steps:

[0309]

[0310]

[0311] (1) Dissolve compound 4-chloro-2-hydroxybenzaldehyde (1k, 1.56 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), reflux for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution to 0 - 10 °C and filter it under vacuum with a pump to obtain 1.51 g of yellow solid, getting compound 2k with a yield of 86%.

[0312] (2) Dissolve compound 2k (351 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 209 mg of 3-boronic acid-L-phenylalanine ( 10 B, 1 mmol), heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution and recrystallize to obtain 473 mg of 4-Cl-BNC-3 with a yield of 79.8%.

[0313] The spectral data of 4-Cl-BNC-3 is: ESI-MS (m / z): 593 [M + H] + ;

[0314] 11H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.21 (d, J = 8.6 Hz, 4H), 6.41–6.16 (m, 6H), 3.53 (dt, J = 20.7, 10.1 Hz, 6H), 2.82 (s, 2H), 2.71 (d, J = 0.6 Hz, 2H), 2.2 (d, J = 8.1 Hz, 1H), 2.14–1.85 (m, 2H).

[0315] Example 22

[0316] This example provides a multi-boron complex (4Br-BNC-3), whose structure is shown below. Its preparation method includes the following steps:

[0317]

[0318] (1) Dissolve compound 4-bromo-2-hydroxybenzaldehyde (1l, 2.01 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), reflux for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution to 0 - 10 °C and filter it under vacuum with a pump to obtain 1.98 g of yellow solid, getting compound 2l with a yield of 90%.

[0319] (2) Dissolve compound 2l (440 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 209 mg of 3-borono-L-phenylalanine ( 10 B, 1 mmol), heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution and recrystallize to obtain 473 mg of 4-Br-BNC-3 with a yield of 69.3%.

[0320] The spectral data of 4-Br-BNC-3 is: ESI-MS (m / z): 553 [M + H] + ; 1H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.21 (d, J = 8.5 Hz, 4H), 6.41–6.16 (m, 6H), 3.51 (dt, J = 20.7, 10.1 Hz, 6H), 2.8 (s, 2H), 2.7 (d, J = 0.6 Hz, 2H), 2.1 (d, J = 8.1 Hz, 1H), 2.13–1.88 (m, 2H).

[0321] Example 23

[0322] This example provides a multi-boron complex (4NO2-BNC-4) with the structure shown below. Its preparation method includes the following steps:

[0323]

[0324] (1) Dissolve 2-hydroxy-4-nitrobenzaldehyde (1m, 1.67 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), reflux for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution to 0 - 10 °C and filter it under vacuum to obtain 1.6 g of yellow solid, getting compound 2m with a yield of 86%.

[0325] (2) Dissolve compound 2m (372 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 209 mg of 4-borono-L-phenylalanine ( 10 B, 1 mmol), heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution and recrystallize to obtain 500 mg of 4-NO2-BNC-4 with a yield of 81.4%.

[0326] The spectral data of 4-NO2-BNC-4 are: ESI-MS (m / z): 614 [M + H] + ;

[0327] 1 1H NMR (300 MHz, DMSO-d6) δ 8.34 (s, 2H), 7.21 (d, J = 8.6 Hz, 4H), 6.42–6.18 (m, 6H), 3.58 (dt, J = 20.6, 10.2 Hz, 6H), 2.82 (s, 2H), 2.73 (d, J = 0.6 Hz, 2H), 2.31 (d, J = 8.1 Hz, 1H), 2.14–1.85 (m, 2H).

[0328] Example 24

[0329] This example provides a multi-boron complex (4NO2-BNC-3) with the structure shown below. Its preparation method includes the following steps:

[0330]

[0331] (1) Dissolve compound 2-hydroxy-4-cyanobenzaldehyde (1m, 1.67 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), and reflux for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution to 0 - 10 °C, and filter it with a vacuum pump to obtain 1.71 g of yellow solid, yielding compound 2m with a yield of 91.9%.

[0332] (2) Dissolve compound 2m (372 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 209 mg of 3-borono-L-phenylalanine ( 10 B, 1 mmol), and heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution and perform recrystallization to obtain 498 mg of 4-NO2-BNC-3 with a yield of 81.1%.

[0333] The spectral data of 4-NO2-BNC-3 are as follows: ESI-MS (m / z): 614 [M + H] + ;

[0334] 1 1H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.2 (d, J = 8.6 Hz, 4H), 6.4–6.15 (m, 6H), 3.53 (dt, J = 20.7, 10.1 Hz, 6H), 2.81 (s, 2H), 2.74 (d, J = 0.6 Hz, 2H), 2.2 (d, J = 8.1 Hz, 1H), 2.14–1.85 (m, 2H).

[0335] Example 25

[0336] This example provides a multi-boron complex (4CN-BNC-4), whose structure is shown below. Its preparation method includes the following steps:

[0337]

[0338] (1) Dissolve compound 2-hydroxy-4-cyanobenzaldehyde (1n, 1.47 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), and reflux for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution to 0 - 10 °C, and filter it with a vacuum pump to obtain 1.25 g of yellow solid, yielding compound 2n with a yield of 75.3%.

[0339] (2) Dissolve compound 2n (332 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 209 mg of 4-borono-L-phenylalanine ( 10 B, 1 mmol). Heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution, and recrystallize to obtain 4-CN-BNC-4, 489 mg, with a yield of 85%.

[0340] The spectral data of 4-CN-BNC-4 are as follows: ESI-MS (m / z): 575 [M+H] + ;

[0341] 1 1H NMR (300 MHz, DMSO-d6) δ 8.34 (s, 2H), 7.21 (d, J = 8.6 Hz, 4H), 6.41–6.18 (m, 6H), 3.57 (dt, J = 20.6, 10.1 Hz, 6H), 2.81 (s, 2H), 2.71 (d, J = 0.6 Hz, 2H), 2.31 (d, J = 8.1 Hz, 1H), 2.13–1.82 (m, 2H).

[0342] Example 26

[0343] This example provides a multi-boron complex (4CN-BNC-3), whose structure is shown below. Its preparation method includes the following steps:

[0344]

[0345]

[0346] (1) Dissolve 2-hydroxy-4-cyanobenzaldehyde (1n, 1.47 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol). Reflux for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution to 0 - 10 °C, and filter with a vacuum pump to obtain 1.35 g of yellow solid, to obtain compound 2n, with a yield of 81.3%.

[0347] (2) Dissolve compound 2n (332 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 209 mg of 3-borono-L-phenylalanine ( 10B, 1 mmol), heated under reflux at 80 - 100 °C for 18 - 30 h. The reaction was monitored by TLC. After the reaction was completed, the reaction solution was cooled and recrystallized to obtain 4 - CN - BNC - 3 480 mg, with a yield of 83.4%.

[0348] The spectral data of 4 - CN - BNC - 3 are as follows: ESI - MS (m / z): 575 [M + H] + ;

[0349] 1 H NMR (300 MHz, DMSO - d6) δ 8.36 (s, 2H), 7.3 (d, J = 8.6 Hz, 4H), 6.5 - 6.15 (m, 6H), 3.55 (dt, J = 20.7, 10.1 Hz, 6H), 2.83 (s, 2H), 2.72 (d, J = 0.6 Hz, 2H), 2.2 (d, J = 8.1 Hz, 1H), 2.14 - 1.85 (m, 2H).

[0350] Example 27

[0351] This example provides a multi - boron complex (4OCH3 - BNC - 4), the structure of which is shown below. Its preparation method includes the following steps:

[0352]

[0353] (1) Dissolve compound 2 - hydroxy - 4 - methoxybenzaldehyde (1o, 1.52 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), and reflux for 18 - 30 h. The reaction was monitored by TLC. After the reaction was completed, the reaction solution was cooled to 0 - 10 °C and filtered by vacuum pump to obtain 1.45 g of yellow solid, obtaining compound 2o, with a yield of 84.8%.

[0354] (2) Dissolve compound 2o (342 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N - dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol), under nitrogen protection, heat under reflux at 80 - 100 °C for 4 h, then add 209 mg of 4 - boric acid - L - phenylalanine ( 10 B, 1 mmol), heat under reflux at 80 - 100 °C for 18 - 30 h. The reaction was monitored by TLC. After the reaction was completed, the reaction solution was cooled and recrystallized to obtain 4 - OCH3 - BNC - 4 475 mg, with a yield of 81.2%.

[0355] The spectral data of 4 - OCH3 - BNC - 4 are as follows: ESI - MS (m / z): 585 [M + H] + ;

[0356] 1 1H NMR (300 MHz, DMSO-d6) δ 8.3 (s, 2H), 7.2 (d, J = 8.6 Hz, 4H), 6.41–6.18 (m, 6H), 3.56 (dt, J = 20.6, 10.1 Hz, 6H), 2.84 (s, 2H), 2.71 (d, J = 0.6 Hz, 2H), 2.3 (d, J = 8.1 Hz, 1H), 2.13–1.82 (m, 2H).

[0357] Example 28

[0358] This example provides a multi-boron complex (4OCH3-BNC-3), whose structure is shown below. Its preparation method includes the following steps:

[0359]

[0360] (1) Dissolve compound 2-hydroxy-4-methoxybenzaldehyde (1o, 1.52 g, 10 mmol) in 80 - 200 mL of ethanol, then add propylenediamine (0.37 g, 5 mmol), reflux for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution to 0 - 10 °C and filter it under vacuum with a pump to obtain 1.45 g of yellow solid, getting compound 2o with a yield of 84.8%.

[0361] (2) Dissolve compound 2o (342 mg, 1 mmol) in organic solvents such as acetonitrile, dichloroethane, N,N-dimethylformamide, dimethyl sulfoxide, etc., then add 122 mg of boric acid ( 10 B, 2 mmol). Under nitrogen protection, heat and reflux at 80 - 100 °C for 4 h, then add 209 mg of 3-borono-L-phenylalanine ( 10 B, 1 mmol), heat and reflux at 80 - 100 °C for 18 - 30 h. Monitor the reaction by TLC until completion. Cool the reaction solution and recrystallize to obtain 480 mg of 4-OCH3-BNC-3 with a yield of 82%.

[0362] The spectral data of 4-OCH3-BNC-3 is: ESI-MS (m / z): 585 [M + H] + ;

[0363] 1 1H NMR (300 MHz, DMSO-d6) δ 8.36 (s, 2H), 7.3 (d, J = 8.6 Hz, 4H), 6.4–6.15 (m, 6H), 3.55 (dt, J = 20.7, 10.1 Hz, 6H), 2.86 (s, 2H), 2.73 (d, J = 0.6 Hz, 2H), 2.2 (d, J = 8.1 Hz, 1H), 2.14–1.82 (m, 2H).

[0364] Test Example

[0365] Test Example 1: Cytotoxicity Experiment

[0366] Human glioma cells U87, human hepatoma cells HepG2, human umbilical vein endothelial cells HUVEC, human normal liver cells L02, and mouse breast cancer cells 4T1 were cultured in DMEM cell culture medium containing peptide bovine serum in a 37 °C, 5% CO2 incubator. U87 cells, HepG2 cells, HUVEC cells, and 4T1 cells in the logarithmic growth phase were treated with trypsin digestion solution for cell culture to prepare a cell suspension with a concentration of 4×10 5 . 200 μL of the culture was added to a 96-well cell culture plate and cultured for 12 hours. After the cells adhered and grew, the supernatant was removed, and the tissue culture medium of the control group (without adding drugs) and the test group (adding drugs) was added, and incubated under the conditions of 37 °C, 5% CO2, constant temperature, and saturated humidity for 16 h. The 96-well cell culture plate was taken out, and after observing the cell state under an inverted microscope, 20 μL of cck-8 solution was added to each well and incubated for another 2 h. The 96-well cell culture plate was placed in an enzyme-linked immunosorbent assay (ELISA) reader for detection. The detection results are as Figures 1 to 9 shown. The multi-boron complexes in this test example were 4OH-BNC-4 of Example 4, 4OH-BNC-3 of Example 10, and 4F-BNC-3 of Example 11.

[0367] Figures 1 to 5 They are respectively the cytotoxicity test results of the multi-boron complex 4OH-BNC-4 of Example 4 in U87, HepG2, HUVEC, L02, and 4T1 cells.

[0368] Figures 6 to 7 They are respectively the cytotoxicity test results of the multi-boron complex 4OH-BNC-3 of Example 10 in L02 and 4T1 cells.

[0369] Figures 8 to 9 They are respectively the cytotoxicity test results of the multi-boron complex 4F-BNC-3 of Example 11 in L02 and 4T1 cells.

[0370] According to Figures 1 to 9 shown, the multi-boron complexes of the present invention have excellent biosafety. Especially when the concentration does not exceed 400 μM, these multi-boron complexes all show good biocompatibility, laying a foundation for their further biological applications.

[0371] Table 1 shows the relative growth rate (RGR) of U87, HepG2, HUVEC, L02, and 4T1 cells under the condition of 400 μM multi-boron complex.

[0372] Table 1 Relative Growth Rate (RGR) of Cells Measured by CCK-8 Colorimetric Method

[0373]

[0374] Experimental Example 2: Evaluation of Boron Uptake Ability of Polyboron Complexes in Different Cell Lines

[0375] To investigate the enrichment ability of this type of polyboron complex in tumor cells, U87 cells, HepG2 cells, HUVEC cells, and 4T1 cells in the logarithmic growth phase were taken and an appropriate amount of DMEM culture medium (10% fetal bovine serum, 100 U / mL penicillin) was added. The cell concentration was adjusted to 1×10 5 cells / mL and inoculated into a 6-well culture plate. After culturing for 24 h, the prepared test drugs (polyboron complex or BPA) were added respectively, and the final concentration of the drug was made 300 μM. Then it was placed in a 5% CO2 incubator and cultured at 37 °C for 24 h. After that, the culture medium in the culture dish was removed with a pipette gun, washed with PBS (3×1 mL), 1 mL of trypsin was added to the culture dish, and then it was placed in a 37 °C constant temperature CO2 incubator and cultured for 3 min. During this period, it was observed under a microscope whether the cells shrank and became round. After the cells shrank and became round, 1 mL of culture medium was quickly added to terminate the digestion, and the adherent cells were gently pipetted to make all the cells fall off the bottom of the culture dish. Then the cell suspension was transferred to a centrifuge tube, diluted, and the number of cells per well was counted using a hemocytometer. The above cell suspension was centrifuged to remove the supernatant, and washed with PBS (3×1 mL). 0.5 mL of nitric acid (0.1%) and 0.5 mL of Triton X-100 (0.1%) were added to the washed centrifuge tube containing cells for digestion; the boron content in the cells was measured by ICP-MS method. Combining the number of cells in each group of samples, the relative uptake efficiency of the polyboron complex relative to BPA in tumor cells and normal cells was calculated, and the uptake results are as Figures 10 to 13 shown. The polyboron complexes in this experimental example used Compound A in Example 1, 4OH-BNC-4 in Example 4, 4OH-BNC-3 in Example 10, and 4F-BNC-3 in Example 11.

[0376] Figure 10 shows the relative cell uptake efficiency of Compound A and BPA in HepG2 cells, 4T1 cells, and U87 cells respectively; Figure 11 shows the relative cell uptake efficiency of 4OH-BNC-4 and BPA in HepG2 cells, 4T1 cells, and U87 cells respectively; Figure 12 shows the relative cell uptake efficiency of 4OH-BNC-3 and BPA in U87 cells, 4T1 cells, and HUVEC cells respectively; Figure 13 shows the relative cell uptake efficiency of 4F-BNC-3 and BPA in 4T1 cells and HUVEC cells respectively.

[0377] FromFigures 10 to 13 The relative uptake efficiencies of the polyboron complex compounds A, 4OH-BNC-4, 4OH-BNC-3, and 4F-BNC-3 in tumor cells and normal cells relative to the traditional BNCT drug BPA can be obtained. The boron uptake content of the polyboron complex in tumor cells is significantly higher than that of BPA, indicating that the compounds of the present invention can be used as BNCT boron drugs and have the potential to kill tumor cells. Moreover, the probability of capturing neutrons by neutron irradiation is much greater than that of BPA, and thus it can be inferred that its ability to kill tumor cells should be much better than that of BPA.

[0378] Application Example 1: In vitro activity evaluation of BNCT mediated by polyboron complex

[0379] At the BNCT Center of Xiamen Hongai Hospital, BNCT experiments were carried out using 4T1 cells. 300 μmol of the polyboron complex and BPA were respectively added to 4T1 cells, and the non-drug group was used as a control (Control), and incubated for 20 h. After the culture was completed, the cells were washed 3 times with PBS, digested with trypsin, and the cell count was performed. 1 ml of a total of 100,000 cells was transferred to a 1.5 ml centrifuge tube, and a certain neutron fluence irradiation intensity was selected for BNCT irradiation. According to the irradiation conditions, it was divided into 3 groups. One group was selected for BNCT irradiation (irradiation for 9 min) with an average neutron flux of 21309.74 n / cm² / s for 9 minutes; one group was selected for BNCT irradiation (irradiation for 12 min) with an average neutron flux of 21274.09 n / cm³ / s for 12 minutes; one group had no irradiation (w / o irradiation). After the irradiation was completed. Then, 4T1 cells (300 cells / well, 2 ml) were inoculated into a 6-well plate and placed in an incubator for 7 days. The fresh medium was changed every 48 h during the process. After 7 days, after removing the medium, it was gently washed with PBS, fixed with 4% paraformaldehyde (1 ml) for 30 - 60 min, washed once with PBS, stained with crystal violet (1 ml) for 10 - 20 min, washed several times with PBS, and air-dried for photographing. The experimental results are shown in Figures 14 to 16 。The polyboron complex used in this application test example was 4OH-BNC-4 of Example 4, 4OH-BNC-3 of Example 10, and 4F-BNC-3 of Example 11.

[0380] Figure 14 These are the cell pictures of different drug groups in this application example after different irradiation conditions. Figure 15 This is the number of cell colony formations. Figure 16 This is the colony formation efficiency of the two irradiation groups.

[0381] As Figures 14 to 16As shown, under the irradiation of the same neutron fluence, it can be seen from the figure that the multi-boron complexes 4OH-BNC-4, 4OH-BNC-3 and 4F-BNC-3 significantly reduced the colony formation rate of 4T1 cells under neutron irradiation, further indicating that the BNCT effects mediated by 4OH-BNC-4, 4OH-BNC-3 and 4F-BNC-3 have an obvious killing effect on 4T1 cells, and the tumor cell killing effect of the multi-boron complex is stronger than that of BPA. Thus, the multi-boron complex of the present invention can be used as a boron drug for BNCT and has great potential in tumor treatment.

[0382] Test Example 3: UV Determination

[0383] The multi-boron complex of the present invention was subjected to UV determination. The mother liquor solvent system of the multi-boron complex used in the UV determination experiment was a phosphate buffer system containing 10% NaOH (500 mM). The mother liquor was prepared into a standard stock solution of 20 mM. The concentration of the multi-boron complex selected for the UV absorption spectrum determination was 50 μM, and the absorption spectrum was set in the range of 300 - 500 nm.

[0384] Compounds for UV determination: 4OH-BNC-4 of Example 4, 4H-BNC-4 of Example 12, 4CH3-BNC-4 of Example 18, 4Cl-BNC-4 of Example 20. The UV determination results are as Figure 17 shown.

[0385] Test Example 4: Fluorescence Determination

[0386] The fluorescence properties of the multi-boron complex of the present invention were further studied. The mother liquor solvent system of the multi-boron complex used in the fluorescence property determination experiment was a phosphate buffer system containing 10% NaOH (500 mM). The mother liquor was prepared into a standard stock solution of 20 mM. The concentrations of the multi-boron complex selected for the fluorescence emission spectrum determination were 50 μM, 100 μM, and 200 μM. Its excitation wavelength was 310 nm or 405 nm, and the detection range of the fluorescence emission spectrum was set at 400 - 700 nm. When detecting, the excitation slit width of the fluorescence spectrophotometer was 10, and the emission slit width was 5.

[0387] Compounds for fluorescence determination: BNC-4 series compounds (4CH3-BNC-4 of Example 18, 4H-BNC-4 of Example 12, 4OH-BNC-4 of Example 4, 4Cl-BNC-4 of Example 20), and BNC-3 series compounds (4CH3-BNC-3 of Example 19, 4H-BNC-3 of Example 13, 4NO2-BNC-3 of Example 24, 4CN-BNC-3 of Example 26, 4F-BNC-3 of Example 11, 4OH-BNC-3 of Example 10). The fluorescence determination results are as Figure 18and Figure 19 as shown

[0388] Figure 18 are the fluorescence measurement results of BNC-4 series compounds, indicating that BNC-4 series compounds have good fluorescence properties at the in vitro level; Figure 19 are the fluorescence measurement results of BNC-3 series compounds, indicating that these compounds also have good fluorescence properties. It can be seen that the multi-boron complex of the present invention has potential fluorescence imaging properties and has the application prospect of diagnosis and treatment integration. The fluorescence imaging property of the boron drug of the present invention enables researchers to more accurately observe and evaluate the uptake of boron drugs in cells, helping researchers observe and verify the targeting of boron drugs at the molecular level, ensuring that the drugs can accurately reach and stay in tumor cells, realizing the diagnosis and treatment integration of BNCT boron drugs, and thus optimizing the treatment effect of BNCT.

[0389] Test Example 5: Cytotoxicity Experiment / Cytotoxicity Determination

[0390] Using an equal mass of fructose as a co-solvent, a 20 mM multi-boron complex stock solution was prepared with a phosphate buffer of 10% NaOH (500 mM) and gradient diluted into different concentrations to examine the survival rate of cells at different drug concentrations. Human glioma cells U87, human triple-negative breast cancer cells MDA-MB-468, and human pancreatic cancer cells PANC-1 were cultured in DMEM cell culture medium containing fetal bovine serum in an incubator at 37 °C and 5% CO2. The U87 cells, MDA-MB-468 cells, and PANC-1 cells in the logarithmic growth phase were treated with trypsin digestion solution to prepare a cell suspension with a concentration of 4×10 5 . The cell suspension was added to a 96-well cell culture plate and cultured for 12 hours. After the cells adhered and grew, the supernatant was removed and added to the culture media of the control group (without adding drugs, i.e., the drug concentration was 0) and different concentration test groups (adding drugs), and incubated at 37 °C, 5% CO2, constant temperature, and saturated humidity for 24 h. The 96-well cell culture plate was taken out, and after observing the cell state under an inverted microscope, 20 μL of cck-8 solution was added to each well and incubated for another 2 h. The 96-well cell culture plate was placed in an enzyme-linked immunosorbent assay (ELISA) reader for detection. The multi-boron complex drugs in this test example: BNC-4 series compounds (4H-BNC-4 in Example 12, 4OH-BNC-4 in Example 4, 4CH3-BNC-4 in Example 18), and BNC-3 series compounds (4OH-BNC-3 in Example 10, 4H-BNC-3 in Example 13, 4CH3-BNC-3 in Example 19, 4F-BNC-3 in Example 11, 4CN-BNC-3 in Example 26). Figures 20 to 23 shows the cytotoxicity test results of the multi-boron complex of the present invention. Specifically, the drug concentrations in this test example can be seen in detailFigures 20 to 23 As shown, for example, the drug concentration can be 0.2 mM, 0.4 mM, 0.6 mM, 0.8 mM, 1 mM, or 50 μM, 100 μM, 200 μM, 300 μM, 400 μM, 500 μM, 600 μM, 700 μM, 800 μM, 1000 μM.

[0391] Figure 20 It is a graph of the U87 cell cytotoxicity test results of the BNC-4 series of polyboron complexes. Figure 21 、 Figure 22 and Figure 23 They are graphs of the U87, PANC-1, and MDA-MB-468 cell cytotoxicity test results of the BNC-3 series of polyboron complexes, respectively.

[0392] According to Figures 20 to 23 it can be known that the polyboron complexes have excellent safety. Especially when the concentration is within 800 μM, these polyboron complexes of the present invention all show good biocompatibility, laying a foundation for their further biological applications.

[0393] Table 2 shows the relative growth rate (RGR) of U87, PANC-1, and MDA-MB-468 cells under the condition of 800 μM polyboron complex (BNC-3 series).

[0394] Table 2 Relative growth rate (RGR) of cells measured by the CCK-8 colorimetric method

[0395]

[0396] Test Example 6: Cell uptake experiment

[0397] In order to further investigate the enrichment ability of polyboron complexes in humanized tumor cells, the uptake of polyboron complexes by various tumor cells is now studied.

[0398] Take U87 cells, MDA-MB-468 cells, and PANC-1 cells in the logarithmic growth phase and add an appropriate amount of DMEM culture medium (10% fetal bovine serum, 100 U / mL penicillin), and adjust the cell concentration to 1×10 5Cells were inoculated at a density of Figures 24 to 25 cells / ml in a 6-well culture plate and cultured for 24 h. Then, fructose of equal mass was used as a co-solvent, and a 20 mM polyboron complex stock solution and BPA were prepared with a phosphate buffer of 10% NaOH (500 mM). They were respectively diluted to 600 μM with DMEM culture medium and added to the adherent cells. Then, the cells were further placed in a 5% CO2 incubator and cultured at 37 °C for 4 h. After that, the culture medium in the culture dish was removed with a pipette, and the cells were washed with PBS (3×1 mL). 1 mL of trypsin was added to the culture dish, and then the dish was placed in a 37 °C constant-temperature CO2 incubator for 3 min. During this period, it was observed under a microscope whether the cells shrank and became round. After the cells shrank and became round, 1 mL of culture medium was quickly added to terminate the digestion, and the adherent cells were gently pipetted to make all the cells detach from the bottom of the culture dish. Then, the cell suspension was transferred to a centrifuge tube, diluted, and the number of cells per well was counted using a hemocytometer. The above cell suspension was centrifuged to remove the supernatant, and the cells were washed with PBS (3×1 mL). 0.5 mL of nitric acid (0.1%) and 0.5 mL of Triton X-100 (0.1%) were added to the washed centrifuge tube containing cells for digestion; the boron content in the cells was measured by ICP-MS. Combining the number of cells in each group of samples, the boron uptake of the polyboron complex and BPA in tumor cells was calculated, and the uptake results are shown in

[0399] Figure 24 Figure Figures 24 to 25 shows the boron uptake of BNC-4 series polyboron complexes and the traditional BNCT drug BPA in U87 tumor cells. Figure 25 Figure shows the boron uptake of BNC-3 series polyboron complexes and BPA in U87, MDA-MB-468, and PANC-1 tumor cells.

[0400] As can be seen from the results, the boron uptake content of the polyboron complex of the present invention by tumor cells is excellent, indicating that the polyboron complex of the present invention has excellent tumor cell killing ability when applied in the field of BNCT.

[0401] In addition, the boron uptake of the compounds of the present invention in tumor cells is also greatly improved compared with the traditional BNCT drug BPA, indicating that the probability of the compounds of the present invention capturing neutrons by receiving neutron irradiation is much greater than that of BPA. Furthermore, it can be inferred that its killing ability to tumor cells should be much better than that of BPA. Obviously, the present invention has excellent application prospects in the field of BNCT.

[0402] Application Example 2: Evaluation of Cell Efficacy

[0403] To further investigate the cell efficacy of the multi-boron complex in humanized tumor cells, a BNCT experiment was conducted using U87 cells at the BNCT Center of Xiamen Hongai Hospital.

[0404] Using an equal mass of fructose as a co-solvent, a 20 mM multi-boron complex stock solution and BPA were prepared with a phosphate buffer of 10% NaOH (500 mM). 600 μM of the multi-boron complex and BPA were added to U87 cells respectively as the treatment groups, and the non-drug group was used as the control group (Control), and incubated for 4 h. After the culture, the cells were washed 3 times with PBS, digested with trypsin, and cell counting was performed. 1 ml of a total of 100,000 cells was transferred to a 1.5 ml centrifuge tube, and a certain neutron fluence irradiation intensity was selected for BNCT irradiation. According to the irradiation conditions, it was divided into two groups. One group selected an average neutron flux of 16059762 n / cm 2 / s and an irradiation time of 9 minutes (irradiation); one group had no irradiation (w / o irradiation). The irradiation was completed. Then, U87 cells (600 cells / well, 2 mL) were inoculated into a 6-well plate and cultured in an incubator for 7 days. Fresh medium was changed every 48 h during the period. After 7 days, after removing the medium, the cells were gently washed with PBS, fixed with 4% paraformaldehyde (1 ml) for 30 - 60 min, washed once with PBS, stained with crystal violet (1 ml) for 10 - 20 min, washed several times with PBS, and air-dried for photographing. The experimental results are as Figure 26 and Figure 27 shown. The multi-boron complexes in this test example: 4CN-BNC-3 of Example 26, 4CH3-BNC-3 of Example 19, 4H-BNC-4 of Example 12.

[0405] Figure 26 These are the cell result diagrams of different drug groups in this application example under different irradiation conditions. Figure 27 The left figure in the middle is the cell number diagram of this application example; the right figure is the inhibition rate of cell clone formation of this application example.

[0406] As Figure 26 and Figure 27As shown, under the irradiation of the same neutron fluence, the multi-boron complexes (4CN-BNC-3, 4CH3-BNC-3, 4H-BNC-4) of the present invention significantly reduced the colony formation rate of U87 cells after neutron irradiation, and the cell efficacy of 4CH3-BNC-3 and 4H-BNC-4 of the present invention was significantly better than that of BPA, further indicating that the multi-boron complexes of the present invention have a strong tumor cell killing effect when applied to BNCT. In summary, the multi-boron complexes of the present invention have excellent application prospects as BNCT boron drugs.

[0407] Application Example 3: Study on Boron Distribution at the In Vivo Level

[0408] Based on the results obtained at the cell level, a U87 xenograft tumor model was constructed. The tumor-bearing nude mice were randomly divided into 5 groups, with 3 mice in each group. Using fructose of equal mass as a co-solvent, a mother liquor of the multi-boron complex at 27.12 mg / ml was prepared with a phosphate buffer of 10% NaOH (500 mM), and administered by tail vein injection at a dosage of 271.2 mg / kg (0.5 mmol / kg); the control group was injected with the same molar amount (0.5 mmol / kg) of BPA via the tail vein. At different time points after administration (0.5 h, 1 h, 2 h, 4 h, 8 h) or (0.5 h, 1 h, 2 h, 4 h), the experimental mice were sacrificed by orbital blood collection and dissection after death, the tumors were removed, and the tumor tissues and blood were digested using a microwave digestion instrument to obtain the extract of the sample to be measured, and the boron content of the compounds in each extract was analyzed using ICP-MS, and the detection results are as Figure 28 shown. Taking BPA as a reference, the distribution characteristics of the multi-boron complex in the tumor tissues and blood of tumor-bearing mice under a reasonable dosage were explored, and the T / B ratio was calculated, and the calculation results are as Figure 29 shown. The multi-boron complex in this test example: 4CH3-BNC-3 of Example 19.

[0409] Figure 28 Respectively show the boron uptake contents of 4CH3-BNC-3 and BPA in the tumor tissues and blood of U87 mice. Figure 29 Respectively show the ratio (T / B) of the boron concentration in the tumor tissues and blood of 4CH3-BNC-3 and BPA in U87 mice.

[0410] From Figure 28 it can be seen that the multi-boron complex 4CH3-BNC-3 of the present invention has a tumor boron uptake of about 8 μg / g at 0.5 h and about 3 μg / g at 4 h; while BPA has a tumor boron uptake of about 3.2 μg / g at 0.5 h and about 0.8 μg / g at 4 h. It can be seen that the tumor boron uptake of the multi-boron complex of the present invention is significantly better than that of BPA, indicating that the multi-boron complex of the present invention has excellent application prospects.

[0411] As Figure 29 It can be seen from the ratio of boron concentration (T / B) in the tumor tissues and blood of mice in the 4CH3-BNC-3 treatment group and BPA treatment group as shown. Among them, for example, the T / B ratio of the multi-boron complex at 4 h is about 1.5, while the T / B of BPA at 4 h is about 1.2. Thus, it can be seen that the ratio of boron concentration in the tumor tissues and blood of the multi-boron complex of the present invention is also higher than that of BPA.

[0412] In summary, the multi-boron complex of the present invention is a BNCT drug with application potential, having excellent tumor uptake effect, capable of facilitating the effective enrichment and retention of B-10 in cancer cells, and being beneficial to the implementation of BNCT.

[0413] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A polyboron complex or a stereoisomer, deuterated product or pharmaceutically acceptable salt thereof, wherein: The polyboron complex structure is shown in the following formula (I): R1 and R2 are each independently selected from: H, F, Cl, Br, I, -OH, -R'OH, alkyl, alkoxy, amino, nitro, cyano, alkylthio, alkenyl, alkynyl, cycloalkyl, cycloalkyloxy, cycloalkylthio, acyl, ester, amide, aryl, heterocyclyl, heteroaryl, heterocycloalkyl, monoalkylamino or dialkylamino; R' is selected from substituted or unsubstituted alkylene groups having 1 to 6 carbon atoms; the substituted groups are selected from halogen, hydroxyl, amino, and nitro; R3 is R5 is selected from H, F, Cl, Br, I, hydroxyl or dihydroxyboryl; a, b are each independently selected from 0, 1, 2, 3 or 4; x is selected from 0, 1, 2, 3 or 4; n is selected from 0, 1 or 2; The above * is the connection site.

2. The polyboron complex according to claim 1 or its stereoisomer, deuterated substance or pharmaceutically acceptable salt, wherein: The polyboron complex structure is shown in the following formula (II):

3. The polyboron complex according to claim 1 or 2, or a stereoisomer, a deuterated substance or a pharmaceutically acceptable salt thereof, wherein: R1 and R2 are each independently selected from H, F, Cl, Br, I, -OH, -R'OH, nitro, cyano, C 1-10 Alkyl or C 1-10 Alkoxy.

4. The polyboron complex according to claim 1 or 2, or a stereoisomer, a deuterated substance or a pharmaceutically acceptable salt thereof, wherein: R1 and R2 are each independently selected from F, Cl, Br, I, -OH, -R'OH, nitro, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, -CH(CH3)CH2CH2CH3, -CH2CH(CH3)CH2CH3, -CH2CH2CH(CH3)2, -CH(C2H5)CH2CH3, -C(CH3)2CH2CH3, -CH(CH3)CH(CH3)2, -CH2C(CH3)3, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy or tert-butoxy.

5. The polyboron complex according to claim 1 or 2, or a stereoisomer, a deuterated substance or a pharmaceutically acceptable salt thereof, wherein: R1 and R2 are each independently selected from H, F, Cl, Br, I, -OH, -R'OH, nitro, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, -CH(CH3)CH2CH2CH3, -CH2CH(CH3)CH2CH3, -CH2CH2CH(CH3)2, -CH(C2H5)CH2CH3, -C(CH3)2CH2CH3, -CH(CH3)CH(CH3)2, -CH2C(CH3)3, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy or tert-butoxy.

6. The polyboron complex according to claim 1 or 2, or a stereoisomer, a deuterated substance or a pharmaceutically acceptable salt thereof, wherein: R1 and R2 are each independently selected from H, F, Cl, Br, I, -OH, -R'OH, C 1-3 Alkyl or C 1-3 Alkoxy.

7. The polyboron complex according to claim 2 or its stereoisomer, deuterated substance or pharmaceutically acceptable salt, wherein: for Preferably 8. The polyboron complex according to claim 2 or 7, or a stereoisomer, a deuterated substance or a pharmaceutically acceptable salt thereof, wherein: R5 is selected from H, F, Cl, Br, I or hydroxyl, preferably H; x is selected from 0, 1, 2, 3 or 4, preferably 0 or 1.

9. The polyboron complex according to claim 2 or its stereoisomer, deuterated substance or pharmaceutically acceptable salt, wherein: R1 and R2 are each independently selected from H, F, Cl, Br, I, -OH, -R'OH, methyl, methoxy or ethoxy; R' is selected from substituted or unsubstituted alkylene with 1 to 3 carbon atoms; the substituted group is selected from halogen and hydroxyl; R5 is selected from H, F, Cl, Br, I, hydroxyl; a, b are each independently selected from 0, 1 or 2; x is selected from 0, 1, 2, 3 or 4; n is selected from 0, 1 or 2.

10. The polyboron complex according to claim 1 or its stereoisomer, deuterated substance or pharmaceutically acceptable salt, wherein: Selected from R1 and R2 are each independently selected from H or methyl, preferably, R1 and R2 are each independently methyl; n is 1; a and b are each independently 0 or 1, preferably, a and b are each independently 1.

11. The polyboron complex according to claim 2 or 7, or a stereoisomer, a deuterated substance or a pharmaceutically acceptable salt thereof, wherein for 12. The polyboron complex according to claim 1 or its stereoisomer, deuterated substance or pharmaceutically acceptable salt, wherein: R1 and R2 are the same, a and b are the same, and R1 and R2 are bilaterally symmetrical with A-A' of the following formula (I) as the symmetry axis:

13. The polyboron complex according to claim 1 or 2, or a stereoisomer, a deuterated substance or a pharmaceutically acceptable salt thereof, wherein: The polyboron complex is selected from one of the following structures:

14. The polyboron complex according to claim 1 or 2, or a stereoisomer, a deuterated substance or a pharmaceutically acceptable salt thereof, wherein: At least one of the Bs in the polyboron complex is 10 B; Preferably, all B of the polyboron complex is 10 B.

15. A pharmaceutical composition, wherein The pharmaceutical composition contains the polyboron complex according to any one of claims 1 to 14 or its stereoisomer, deuterated substance or pharmaceutically acceptable salt, and a pharmaceutically acceptable carrier.

16. The pharmaceutical composition according to claim 15, wherein The pharmaceutical composition further comprises a cosolvent; the cosolvent comprises galactose or fructose; and / or the cosolvent is prepared using a phosphate buffer solution of NaOH.

17. The pharmaceutical composition according to claim 15, wherein The pharmaceutical composition also contains galactose. Based on the total weight of the pharmaceutical composition being 100%, the weight percentage of the polyboron complex or its stereoisomers, deuterated substances or pharmaceutically acceptable salts is 0.05%-90%, and the weight percentage of the galactose is 40%-60%.

18. Use of the polyboron complex according to any one of claims 1 to 14 or its stereoisomer, deuterated product or pharmaceutically acceptable salt, or the pharmaceutical composition according to any one of claims 15 to 17 in the preparation of anti-tumor drugs.

19. The use according to claim 18, wherein: The tumor is selected from glioma, pancreatic cancer, triple-negative breast cancer, liver cancer, melanoma, head and neck tumor, brain tumor, meningioma, pleural mesothelioma, lung cancer, osteosarcoma, cervical cancer or bladder cancer.

20. The use according to claim 18, wherein: The tumor is a central nervous system tumor or breast cancer.

21. The use according to claim 18, wherein: The anti-tumor drug is an anti-tumor drug used under neutron irradiation conditions.

22. A method for preparing a polyboron complex or its stereoisomers, deuterated products or pharmaceutically acceptable salts, wherein: The method comprises the steps of preparing the polyboron complex using compound (1) and compound (2) as raw materials: R1 and R2 are each independently selected from: H, F, Cl, Br, I, -OH, -R'OH, alkyl, alkoxy, amino, nitro, cyano, alkylthio, alkenyl, alkynyl, cycloalkyl, cycloalkyloxy, cycloalkylthio, acyl, ester, amide, aryl, heterocyclic, heteroaryl, heterocycloalkyl, monoalkylamino or dialkylamino; R' is selected from substituted or unsubstituted alkylene with 1 to 6 carbon atoms; the substituted group is selected from halogen, hydroxyl, amino, nitro; R3 is R5 is selected from H, F, Cl, Br, I, hydroxyl or dihydroxyboryl; x is selected from 0, 1, 2, 3 or 4; a, b are each independently selected from 0, 1, 2, 3 or 4; n is selected from 0, 1 or 2; The above * is the connection site.

23. The preparation method according to claim 22, wherein: The method further comprises the step of preparing a compound of formula (1) using a compound of formula (3) and boric acid as raw materials:

24. The preparation method according to claim 23, wherein: The method further comprises the step of preparing a compound of formula (3) using a compound of formula (4), a compound of formula (4') and a compound of formula (5) as raw materials:

25. The preparation method according to claim 24, wherein: The compound of formula (4) and the compound of formula (4') have the same structure.

26. The method for preparing the polyboron complex or its stereoisomer, deuterated product or pharmaceutically acceptable salt according to claim 22, wherein: for

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