CN108239101B

CN108239101B - Compound for preparing compound specifically binding with beta amyloid, preparation method and application thereof

Info

Publication number: CN108239101B
Application number: CN201611207546.XA
Authority: CN
Inventors: 刘渊豪
Original assignee: Neuboron Medtech Ltd
Current assignee: Neuboron Medtech Ltd
Priority date: 2016-12-23
Filing date: 2016-12-23
Publication date: 2020-10-16
Anticipated expiration: 2036-12-23
Also published as: CN108239101A

Abstract

In one aspect, the invention discloses a compound having a structure as shown in formula A, wherein a substituent group R₁Can be-NO₂May also be-NH₂In another aspect, the use of the compounds in the preparation of compounds that specifically bind to β amyloid is disclosed.

Description

Compound for preparing compound specifically binding with beta amyloid, preparation method and application thereof

Technical Field

The invention relates to a novel compound, a preparation method and application of the compound, in particular to application of the compound in preparing a compound specifically binding with beta amyloid.

Background

Alzheimer's disease (generally abbreviated as AD) is the most common dementia among the elderly, and its histopathological manifestations are mainly senile plaque, neurofibrillary tangle and regional nerve cell death caused by apoptosis.

Studies have shown that the abnormal deposition of β Amyloid (Amyloid β -protein, commonly abbreviated as A β) is one of the main pathogenesis of Alzheimer's disease, β Amyloid is a polypeptide containing 39-43 amino acids produced by proteolysis of Amyloid Precursor Protein (APP) through β and gamma secretase, and 40(A β) is common in human body_1～40) Or 42(A β)_1～42) A polypeptide of amino acids, wherein A β_1～42Has stronger toxicity and is easier to accumulate into the core of β amyloid deposit plaques, and the β amyloid deposit plaques formed after β amyloid deposits can trigger neurotoxic effect.

The chemical method for preparing the compound capable of being specifically combined with the beta amyloid is helpful for further researching the relation between the beta amyloid and the pathogenesis of the AD, and more likely provides a new idea for eliminating the beta amyloid and relieving or curing the AD by using a new technology (such as BNCT).

Disclosure of Invention

In one aspect, the invention provides a compound having a structure shown in formula A,

wherein R is₁Can be-NO₂May also be-NH₂，

When R is₁is-NO₂When the compound is 2- (4-nitrobenzene) -6-dihydroxy boron benzothiazole;

when R is₁is-NH₂When the compound is 2- (4-aminobenzene) -6-dihydroxy boron-based benzothiazole.

The boron element in the compounds 2- (4-nitrobenzene) -6-dihydroxy boron-based benzothiazole and 2- (4-aminobenzene) -6-dihydroxy boron-based benzothiazole shown in the structural formula A can be¹¹B may also be¹⁰B, preferably, the boron element in the compound represented by the structural formula A is¹⁰B。

¹⁰B is a nuclide having a large thermal neutron capture cross section, wherein the nuclide having a large thermal neutron capture cross section means a nuclide having a neutron capture cross section 100 times or more as large as the neutron capture cross section of a human body elemental constituent element (C, H, O, N, P, S) under the irradiation of thermal neutrons of the same energy, wherein the neutron capture cross section of H among the human body elemental constituent elements under the irradiation of thermal neutrons of the same energy is the largest, the thermal neutron capture cross section of H is 0.2barn under the condition that the thermal neutron energy is 0.025eV,¹⁰the thermal neutron capture cross section of B is 3800 barn.

Nuclide with large thermal neutron capture cross section¹⁰B, under the irradiation of neutron rays, the following reaction occurs, and energy is radiated:

as is well known to those skilled in the art, the above¹⁰The mechanism of B element and neutron reaction is often used during neutron capture therapy (BNCT). Thus when the compound contains¹⁰B nuclides, the compounds may be used in neutron capture therapy, or the compounds may be used in neutron capture therapy¹⁰The compound of the B element is further used for preparing other compounds which can be applied to the neutron capture treatment process.

In another aspect, the present invention provides a method for preparing a compound represented by structural formula a, wherein 2- (4-nitrobenzene) -6-dihydroxyborylbenzothiazole is prepared by the following reaction:

reacting 2- (4-nitrobenzene) -6-bromobenzothiazole and diboron pinacol ester to generate 2- (4-nitrobenzene) -6-boronic acid pinacol ester benzothiazole;

oxidizing 2- (4-nitrobenzene) -6-boronic acid pinacol ester benzothiazole into 2- (4-nitrobenzene) -6-dihydroxy boron based benzothiazole by an oxidizing agent.

The 2- (4-aminobenzene) -6-dihydroxy boron-based benzothiazole is prepared from 2- (4-nitrobenzene) -6-dihydroxy boron-based benzothiazole, wherein the 2- (4-aminobenzene) -6-dihydroxy boron-based benzothiazole is prepared from 2- (4-nitrobenzene) -6-dihydroxy boron-based benzothiazole through reduction reaction.

In a third aspect, the present invention provides the use of the compounds 2- (4-nitrophenyl) -6-dihydroxybenzothiazole and 2- (4-aminophenyl) -6-dihydroxybenzothiazole of formula a for the preparation of compounds that specifically bind to beta-amyloid, which is referred to as 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole, as not specifically described herein.

Preferably, in the application, the compound specifically binding to the beta amyloid is prepared from a compound shown in a structural formula A by the following method:

the 2- (4-nitrobenzene) -6-dihydroxyboryzothiazole is reduced to the 2- (4-aminobenzene) -6-dihydroxyboryzothiazole by a reduction reaction;

the 2- (4-aminobenzene) -6-dihydroxy boron-based benzothiazole, the methyl iodide and the silver trifluoromethanesulfonate react at high temperature to generate the 2- (4-methylaminobenzene) -6-dihydroxy boron-based benzothiazole.

The invention provides a novel compound containing boron and application of the compound in preparation of a compound specifically combined with beta amyloid, and provides a novel technical support for researching the beta amyloid. The invention only exemplifies the use of said compounds in the preparation of compounds that specifically bind to amyloid beta, without excluding other uses of the compounds of formula a of the invention.

Drawings

FIG. 1 is a schematic representation of 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole¹A HNMR map;

FIG. 2 is a schematic plan view of a neutron capture treatment device of an accelerator neutron source;

FIG. 3 is a schematic plan view of a neutron capture treatment apparatus of a reactor neutron source;

FIG. 4 is a schematic view showing (1) and (2)¹¹C-labeled 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole shows stability charts at 30min and 60min respectively;

FIG. 5 is a drawing A and a drawing B each showing a drawing for injection¹¹PET images of control mice and SAMP8 model mice 30min after C-labeled 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole;

FIG. 6 is bovine serum albumin and H₃ ¹⁰BO₃The mixed solution is respectively irradiated by radiation at different positions away from the outlet of the collimator to obtain SDS-PAGE electrophoresis patterns;

FIG. 7 shows the general structural formulas of 2- (4-nitrophenyl) -6-dihydroxyborybenzothiazole and 2- (4-aminobenzene) -6-dihydroxyborybenzothiazole.

Detailed Description

The technical solutions of the present invention are further described in detail below by examples to enable those skilled in the art to practice the technical solutions with reference to the description, and it should be understood that the examples are not intended to limit the scope of the claims of the present invention.

Terms such as "having," "including," and "comprising," as used herein, do not preclude the presence or addition of one or more other ingredients or combinations thereof.

As used herein, the term "compound represented by the formula A" refers to 2- (4-nitrophenyl) -6-dihydroxyboryzothiazole and 2- (4-aminobenzene) -6-dihydroxyboryzothiazole, unless otherwise specified.

The fast neutron is a neutron with an energy zone larger than 40keV, the super-thermal neutron energy zone is between 0.5eV and 40keV, and the thermal neutron energy zone is smaller than 0.5 keV.

The compound capable of being specifically combined with beta amyloid provided by the invention is 2- (4-methylaminobenzene) -6-dihydroxy boron benzothiazole, and the structure of the compound is confirmed as shown in the attached figure 1. The compounds may be used in conjunction with neutron capture therapy devices to eliminate amyloid beta-deposited plaques.

As shown in fig. 2 or fig. 3: the neutron capture treatment device comprises a neutron source, a beam shaping body and a collimator, wherein the beam shaping body comprises a reflector, a retarder, a thermal neutron absorber and a radiation shielding device, and the neutron source comprises an accelerator neutron source and a reactor neutron source.

In the process of eliminating beta amyloid deposit plaques by using a neutron capture treatment device, it is usually required to adjust fast neutrons in a mixed radiation field from a neutron source to epithermal neutrons in a beam shaping body of the neutron capture treatment device and reduce the content of other harmful rays in the mixed radiation field, although nuclides on a compound specifically bound with the beta amyloid are nuclides with a large thermal neutron capture cross section, considering that the energy of the neutron beam can be attenuated to a certain extent along with the increase of the distance between the collimator of the neutron capture treatment device and a compound capable of specifically binding with the beta amyloid, and the energy of the neutrons can be retarded to different extents by other substances in the process that the neutron beam reaches the compound specifically bound with the beta amyloid, therefore, in order to ensure the energy and neutron intensity of the compound neutrons reaching the amyloid β specifically, it is generally necessary to slow fast neutrons in the beam shaper into epithermal neutrons, so as to increase the content of epithermal neutrons in the neutron beam exiting from the collimator.

The neutron source shown in fig. 2 is a neutron capture treatment device which is an accelerator, wherein an accelerator 10a accelerates protons, expands the cross-sectional area of a proton beam P by a beam expanding device 20, and makes the proton beam P strike a target T and generate neutrons, and the reaction principle is as follows: charged particles such as protons, deuterons, etc. are accelerated by an accelerator to an energy sufficient to overcome the coulomb repulsion of the target nuclei, and undergo nuclear reactions with a metal target T, typically lithium and beryllium, to produce daughter nuclei and neutrons. The method generates a mixed radiation field, when the neutron capture treatment device is used for irradiation, other types of radiation rays need to be reduced as much as possible, the retarder 32a in the beam shaper 30a has the function of adjusting the energy of the mixed radiation field, the reflector 31a reflects the mixed radiation field diffused towards other directions so as to reduce the loss of neutrons, the beam shaper 30a can also comprise a thermal neutron absorber 33a which can absorb thermal neutrons with lower energy, and a layer of radiation shielding device 34a is arranged outside the beam shaper 30a so as to prevent radiation leakage from damaging nearby people. The rear part of the beam shaper 30a is provided with a collimator 40a, and the beam adjusted by the beam shaper 30a is converged by the collimator 40 a.

Fig. 3 shows a neutron capture therapy apparatus in which a neutron source is a reactor, wherein a reactor neutron source 10b transmits a generated neutron beam N to a beam shaping body 30b through a pipeline, the reactor neutron source 10b and a neutron source of an accelerator 10a both generate a mixed radiation field, fast neutrons with higher energy in the mixed radiation field are slowed by a retarder 32b in the beam shaping body 30b into neutrons capable of destroying a beta amyloid structure, and rays diffused to other directions are reflected back to the retarder 32b through a reflector 31b to improve the utilization rate of the rays; the thermal neutron absorber 33b in the beam shaper can absorb thermal neutrons with lower energy in the mixed radiation field to make the epithermal neutron content in the neutron beam N higher, which is converged by the collimator 40b, to improve the accuracy of neutron irradiation.

The technical solution of the present invention is further illustrated by the following examples.

The boron element on the compound is¹⁰B and the compound may contain a radioactive element¹¹C. Unless otherwise specified, all of the boron elements in the boron-containing compounds of the present invention are boron elements¹⁰B。

< example 1> preparation of Compound specifically binding to amyloid beta

The compound 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole specifically binding to amyloid beta can be prepared by the following reaction:

1g of 2- (4-Nitrobenzene) -6-bromobenzothiazole was dissolved in 10mL of ethanol, and 5.39g of SnCl was added₂.2H₂O, stirring the reaction system for 1h at the temperature of 100 ℃ to obtain 2- (4-aminobenzene) -6-bromobenzothiazole;

¹H NMR:400MHz DMSO

8.29(s,1H),7.80-7.82(d,J＝8.8Hz,1H),7.74-7.76(d,J＝8.8Hz,2H),7.58-7.60(m,1H),6.65-6.67(d,J＝8.4Hz,2H),5.95(s,2H)。

adding 16.4mmol of formaldehyde into 1g of 2- (4-aminobenzene) -6-bromobenzothiazole, adding 10mL of Tetrahydrofuran (THF) and 20mL of methanol, adding 0.886g of sodium methoxide to form a reaction solution, stirring the reaction solution at 65 ℃ for reaction for 12 hours, cooling the reaction solution to 25 ℃, and adding 620.41mg of sodium borohydride (NaBH)₄) Then raising the reaction temperature to 65 ℃, and stirring for reaction for 1h to obtain 2- (4-methylaminobenzene) -6-bromobenzothiazole;

¹H NMR:400MHz CDCl₃

7.97(s,1H),7.89-7.91(d,J＝8.8Hz,2H),7.81-7.83(d,J＝8.8Hz,1H),7.52-7.54(m,1H),6.64-6.66(d,J＝8.8Hz,2H),2.93(s,3H)。

a reaction system was prepared from 100mg of 2- (4-methylaminobenzene) -6-bromobenzothiazole, 95.46mg of pinacol diboron and 92.23mg of potassium acetate, 4mL of THF and 2mL of dimethyl sulfoxide (DMSO) were added to the reaction system, and 26.39mg of bis (triphenylphosphine) palladium dichloride (Pd (PPh) was added under a nitrogen-filled condition at 20 ℃₃)₂Cl₂) Stirring and reacting for 12h at the temperature of 90 ℃ to obtain 2- (4-methylaminophenyl) -6-boronic acid pinacol ester benzothiazole, wherein diboronThe boron in the pinacol ester acid is¹⁰B；

To 300mg of 2- (4-methylaminophenyl) -6-boronic acid pinacol ester benzothiazole, 20mL of HF and 10mL of water were added, followed by 875.93mg of sodium metaperiodate (NaIO)₄) Forming a reaction system, and stirring and reacting the reaction system at the temperature of 25 ℃ for 12h to obtain the 2- (4-methylaminobenzene) -6-dihydroxy boronyl benzothiazole. Of the compound¹The HNMR scanning map is shown in figure 1.

¹H NMR:400MHz MeOH

8.27(s,1H),7.83-7.85(m,4H),6.66-6.68(d,J＝7.6Hz,2H),2.85(s,3H)。

Wherein, the 2- (4-nitrobenzene) -6-bromobenzothiazole can be prepared by the following steps:

adding 5g of 2-amino-6-bromo-benzothiazole into 25mL of 10M potassium hydroxide solution, adding 5mL of mixed solution formed by ethylene glycol, and stirring for reacting for 2 hours at 125 ℃ to obtain 2-amino-5-bromobenzothiol;

¹H NMR:400MHz DMSO

7.21-7.26(m,1H),6.99(s,1H),6.81-6.72(m,1H),6.39(s,1H),5.72(s,2H)。

adding 1.48g of p-nitrobenzaldehyde into 2g of 2-amino-5-bromobenzothiol, adding 40mL of DMSO to form a reaction solution, and stirring the reaction solution at 180 ℃ for reaction for 0.5h to obtain 2- (4-nitrobenzene) -6-bromobenzothiazole;

¹H NMR:400MHz DMSO

8.54(s,1H),8.34-8.41(m,4H),8.07-8.09(d,J＝8.8Hz,1H),7.74-7.77(m,1H)。

the specific reaction process for synthesizing 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole in this example is shown in reaction formula II (all boron elements in the reaction formula are boron elements¹⁰B)：

< example 2> preparation of Compound specifically binding to amyloid beta

The synthesis method of 2- (4-nitrobenzene) -6-bromobenzothiazole in this example was the same as that described in < example 1 >.

To 100mg of 2- (4-nitrobenzene) -6-bromobenzothiazole, 90.91mg of pinacol diboron and 87.84mg of potassium acetate were added, 4mL of THF and 2mL of DMSO were added, 25mg of bis (triphenylphosphine) palladium dichloride was added under the condition of nitrogen charging at 20 ℃, and the reaction system was stirred and reacted at 95 ℃ for 15 hours to obtain 2- (4-nitrobenzene) -6-boronic acid pinacol ester benzothiazole, wherein the boron in the pinacol diboron is¹⁰B；

¹H NMR:400MHz CDCl₃

8.44(s,1H),8.35-8.37(d,J＝8.8Hz,2H),8.28-8.30(d,J＝8.8Hz,2H),8.11-8.13(d,J＝8Hz,1H),7.96-7.98(d,J＝8Hz,1H),1.40(s,12H)。

539.7mg of 2- (4-nitrobenzene) -6-boronic acid pinacol ester benzothiazole is added with 30mL of THF and 10mL of water, and then 1.51g of sodium metaperiodate is added, and the reaction system reacts for 23h at the temperature of 25 ℃ to obtain 2- (4-nitrobenzene) -6-dihydroxy boron benzothiazole;

¹H NMR:400MHz DMSO

8.56(s,1H),8.36-8.42(m,4H),8.29(m,2H),8.10-8.12(d,J＝8.4Hz,1H),8.00(m,1H)。

adding 200mg of catalyst Pd/C into 100mL of methanol, adding 180mg of 2- (4-nitrobenzene) -6-dihydroxy boron benzothiazole to form a reaction system, vacuum degassing the reaction system in a hydrogen environment, and reacting for 10min at 25 ℃ to generate 2- (4-aminobenzene) -6-dihydroxy boron benzothiazole;

¹H NMR:400MHz MeOH

8.29(s,1H),7.80-7.84(m,4H),6.74-6.76(d,J＝8.8Hz,2H)。

carrying methyl iodide by nitrogen, heating the methyl iodide to a silver trifluoromethanesulfonate tube at 200 ℃, introducing the methyl iodide into anhydrous acetone in which 2- (4-aminobenzene) -6-dihydroxyborylbenzothiazole is dissolved to form a reaction solution, reacting the reaction solution at 80 ℃ for 5min, and adding water to quench the reaction solution to obtain the 2- (4-methylaminobenzene) -6-dihydroxyborylbenzothiazole.

Wherein C in the methyl iodide may be radioactive¹¹C, 2-The (4-methylaminobenzene) -6-dihydroxyboryzothiazole also has radioactive elements¹¹C, the radioactive compound can thus be used in conjunction with PET to track β the location of amyloid deposition in the brain and diagnosis of AD.

¹H NMR:400MHz MeOH

8.27(s,1H),7.83-7.85(m,4H),6.66-6.68(d,J＝7.6Hz,2H),2.85(s,3H)。

The reaction process of this example is shown in the reaction formula III (in the reaction formula, B is all B)¹⁰B)：

<Example 3>¹¹Application of C-labeled 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole in preparation of β amyloid PET imaging agent

By experimental methods well known to those skilled in the art, from<Example 2>Of (A) synthesized from¹¹The C-labeled 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole is purified by preparative HPLC, the radioactive chemical purity of the purified product is 98.15 percent, the HPLC retention time of the purified product is 5.43min, and the retention time of the purified product is consistent with that of the standard 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole, so that the purified product can be determined to be the required radioactive compound.

Detection by HPLC¹¹The stability of C-labeled 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole in vitro is selected from 30min and 60min, wherein (1) in figure 4 is stability 30min radioactive pattern, (2) is stability 60min radioactive pattern, and radioactive chemical purities of 30min and 60min are both 100%, therefore, the stability of C-labeled 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole is in vitro determined by time¹¹The radiochemical purity of the C-labelled radioactive compound meets the experimental requirements.

<Example 4>¹¹Experiment on specific binding of C-labeled 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole and β amyloid

SAMP8(senescence acellulated mouse rope 8) mouse is the most common animal model for studying AD (Alzheimer's disease) at present, and the brain thereof is the brain of the mouseIn this example, SAMP8 mouse was used as a model mouse, a general laboratory mouse was used as a control mouse, and both the model mouse and the control mouse were 10 months old, and mice containing amyloid deposits were injected into the mice¹¹C-labeled 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole, and then scanned by Micro-PET to investigate whether the 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole and β amyloid protein have the property of specific binding.

Model mice and control mice with a weight of 31.5 + -0.3 g were selected, and 31.0 + -0.6. mu. Ci was injected into the mice¹¹C-labeled 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole, and scanned with Siemens type INVENON Micro-PET with a scanning energy window of 350-650 KeV.

It is well known to those skilled in the art that the main cause of Alzheimer's disease is the accumulation of amyloid beta plaques in the cerebral cortex and hippocampus, and this example analytically determined the uptake of radioactive 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole into the cerebral cortex and hippocampus of SAMP8 model and control mice by Micro-PET scanning and comparison of the brains of model and control mice using PMOD software to show whether the compound specifically binds to the amyloid beta plaques, as shown in tables 1 and 2:

TABLE 1 uptake of radioactive 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole into the cerebral cortex of model and control rats

As can be seen from table 1: at 35 minutes after radiopharmaceutical injection, the ratio of cerebral cortex uptake of model mice to control mice was 2.7, which is higher than the ratio of target to non-target boron concentration of effective boron neutron capture therapy (2.5), and this result indicates that radioactive 2- (4-methylaminobenzene) -6-dihydroxyboryzothiazole can effectively bind to beta amyloid deposition plaques and accumulate at the foci. Boron neutron capture is more likely to be used for treating patients with Alzheimer's disease, and a large amount of radiation dose can be received at the focus, so that the aim of treatment is achieved, and the radiation damage to normal brain tissues is reduced.

TABLE 2 uptake of radioactive 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole by the hippocampal region of model and control mice

As can be seen from Table 2, the hippocampal ratio of model and control mice was 3.2 higher than the target to non-target boron concentration ratio (2.5) of effective boron neutron capture therapy at 25 and 35 minutes after radiopharmaceutical injection, which also demonstrated that radioactive 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole was effective in binding to the amyloid beta plaque and accumulating at the foci.

SAMP8 model mouse is a mouse with accelerated aging Alzheimer disease, a large amount of beta amyloid deposition plaques are accumulated in lesion sites of cerebral cortex and hippocampal region, and as can be seen from experimental data of model mouse and control mouse in tables 1 and 2, cerebral cortex and hippocampal region of SAMP8 model mouse have stronger absorption capacity to 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole compared with normal control mouse, so that 2- (4-methylaminobenzene) -6-dihydroxyborybenzothiazole and beta amyloid are proved to have specificity, and the Alzheimer disease can be treated by boron neutron capture treatment in the future, and another advanced treatment mode is provided for Alzheimer disease patients.

According to the analysis results in Table 2, the ratio of the radiopharmaceutical to the hippocampal region of the brain of the model mouse to the control mouse was 3.2 at 25 to 35 minutes after the injection of radioactive 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole in the mouse, and thus the Micro-PET image of the middle value of 30min was compared with the accumulation of radioactive 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole in the brain.

FIG. 5 is a PET scan at 30min after injection of radioactive 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole and processed by AMIDE software, wherein A is an image of a control mouse injected with a radioactive drug for 30min, in A, (1) is a coronal section scan of the control mouse, (2) is a section scan of the control mouse along the Y-axis, (3) is a section scan of the brain along the X-axis of (1); the image B is the image of SAMP8 model mouse injected with radioactive drug for 30min, and similarly, the image B is (1) the image of the coronal section scan of the model mouse, (2) the image of the coronal section scan of the image along the Y-axis, (3) the image of the coronal section scan of the image along the X-axis of the image of the model mouse.

Wherein (3) in the graph A and (3) in the graph B can reflect the absorption of the brain radiopharmaceuticals, and comparing the two images, the brain of the SAMP8 model mouse in the graph B (3) accumulates a large amount of radiopharmaceuticals relative to the brain of the control mouse in the graph A (3), but the brain of the model mouse is known to have a large amount of beta amyloid deposition plaques, so that the specificity of the 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole on the beta amyloid deposition plaques can be demonstrated, and the future 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole can be used for boron neutron capture treatment.

< example 5> experiment for simulating application of 2- (4 methylaminobenzene) -6-dihydroxyborybenzothiazole in preparation of drug for eliminating beta amyloid

Boric acid (H) for this example₃ ¹⁰BO₃) Instead of 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole, in which boric acid (H)₃ ¹⁰BO₃) The boron element in the composition is¹⁰Simulating β amyloid protein with Bovine Serum Albumin (BSA), placing the mixed solution of boric acid and BSA in the environment of neutron beam generated by neutron capture therapy device, and analyzing the effect of neutrons on BSA and H in SDS-PAGE gel electrophoresis₃ ¹⁰BO₃The effect of neutrons on bovine serum albumin in the presence of such conditions.

First, effect of neutron on bovine serum albumin

Preparing BSA solution with concentration of 0.01% (w/w) with ultrapure water, storing the prepared solution at 4 deg.C, performing experimental operation, placing 1ml of the BSA solution on the central line of the collimator outlet of a neutron capture therapy device, wherein the distance between the solution and the collimator outlet is 2cm,the neutron capture treatment device was set up so that the neutron intensity at the collimator exit was 2.4 × 10¹¹The BSA solution is irradiated for 2 hours in the neutron environment; and taking 1mLBSA solution as a control solution without neutron irradiation.

A BSA solution and a control solution which are irradiated for 2 hours by neutrons are respectively stained by Coomassie brilliant blue and subjected to SDS-PAGE gel electrophoresis, the colors of protein bands in the electrophoretograms of the sample solution and the control solution are respectively quantified by Image J software, the numerical value of the numerical value is used for expressing the relative content of protein, wherein the content of BSA in the control solution is defined as 1, and under the neutron irradiation experimental conditions, the content of BSA after 2 hours of neutron irradiation is 0.8, and the content of BSA is reduced by about 20%, so that the content of protein can be influenced by radiation containing neutron beams.

II, in H₃ ¹⁰BO₃The effect of neutrons on bovine serum albumin in the presence of

Preparation of BSA and H with ultrapure Water₃ ¹⁰BO₃Wherein, in the solution, the concentration of BSA is 0.01% (w/w), H₃ ¹⁰BO₃The concentration of the solution is 0.18M, the prepared solutions are stored at 4 ℃ and are subjected to experimental operation, 8 parts (the number is A, B, C, D, E, F, G, H respectively) are taken from the solutions respectively, each 1mL of the solution is irradiated by a neutron capture treatment device, the 8 parts of the solution are respectively placed on the central line of the outlet of a collimator of the neutron capture treatment device, the distance from the outlet of the collimator to the solution A is 2cm, the distance from the solution B to the outlet of the collimator is 4cm, the distance from the solution C to the outlet of the collimator is 6cm, and the like, beams at the outlet of the collimator comprise neutron rays, gamma rays and other radiation rays, the neutron rays are mainly used for actually destroying proteins, the intensity of the beams is described by the neutron intensity in the beams, wherein the neutron intensity adopted in the embodiment is 2.4 × 10¹¹Irradiating 8 parts of solution in the neutron environment for 2 hours; from said BSA and H₃ ¹⁰BO₃1mL of the solution was used as a control solution which was not neutron irradiated.

The control solution and 8 solutions irradiated with radiation from the neutron capture therapy device were stained with Coomassie Brilliant blue and subjected to SDS-PAGE gel electrophoresis, and SDS-PAGE electrophoretograms of the control solution and 8 solutions are shown in FIG. 6.

In FIG. 6, the first two protein bands are BSA in the control solution, the rest are BSA after the irradiation of the radiation, 8 solutions are all placed on the center line of the collimator outlet, and because the solutions on the center line all contain H₃ ¹⁰BO₃To do so¹⁰B element has larger capture cross section for thermal neutrons, so neutrons in the radiation from the collimator exit pass through the collimator and contain H₃ ¹⁰BO₃The sub-doses are substantially reduced, the further away from the collimator exit the solution is subjected to a lower dose of BSA radiation.

As can be seen from fig. 6, the color of the protein band of each of the 8 neutron-irradiated solutions is lighter to a different degree than the control, and the closer to the collimator outlet, the lighter the color of the protein band in the solution is, indicating that the protein content is reduced more, and the closer to the collimator outlet, the higher the neutron radiation dose is, further indicating that the magnitude of the neutron dose affects the content of BSA in the solution, and the stronger the neutron dose, the lower the content of BSA in the solution after the neutron irradiation.

The colors of the BSA protein bands in the electropherograms of the control solution and 8 solutions were quantified by Image J software, and the values are used to represent the relative content of the proteins, wherein the BSA content in the control solution is defined as 1, and the BSA content after 2h neutron irradiation under the above neutron irradiation experimental conditions is shown in table 3.

As can be seen from Table 3, the BSA content in the neutron-irradiated solution was reduced to various degrees, and the neutron intensity of the solution 2cm from the collimator outlet was 2.4 × 10¹¹After neutron irradiation of 2H, the BSA content is only 5.3%, which is shown in H₃ ¹⁰BO₃Under the existing condition, neutrons can greatly destroy the BSA structure and reduce the content of BSA; and within the allowable range of experimental error, the distance of 8 solutions along with the solutionThe further away from the collimator exit, the overall tendency for the BSA content to decrease further illustrates that the magnitude of the neutron dose affects the BSA content.

TABLE 3 at H₃ ¹⁰BO₃Effect of neutrons on bovine serum albumin in the Presence of

Solution numbering	BSA content (%)
		Control solution	100
A	5.3
		B	2.6
C	18.9
		D	14.0
E	22.9
		F	35.1
G	49.6
		H	60.7

The compounds provided by the invention are 2- (4-methylaminobenzene) -6-dihydroxy boron based benzothiazole and H₃ ¹⁰BO₃Nuclide with large thermal neutron capture cross section¹⁰B, and the compound is capable of specifically binding to β amyloid, the compound is placed in an environment containing β amyloid, the compound forms a higher concentration around β amyloid, and the area where the compound accumulates is irradiated with a neutron beam emitted by a neutron capture therapy device, the energy released by the area being capable of destroying the structure of the protein.

The present invention has been described in detail with reference to the specific embodiments, it should be noted that the above embodiments are only for illustrative purposes and do not represent the scope of the present invention, and that other non-essential modifications and adjustments made according to the teachings of the present invention still belong to the scope of the present invention.

Claims

1. A compound having a structure according to formula A,

wherein R is₁is-NH₂The compound is 2- (4-aminobenzene) -6-dihydroxy boron based benzothiazole; the boron element in the compound is¹⁰B。

2. The method of claim 1, wherein the 2- (4-aminobenzene) -6-dihydroxyboryzothiazole is prepared by reduction of 2- (4-nitrobenzene) -6-dihydroxyboryzothiazole.

3. A method of preparing a compound of claim 2, wherein the 2- (4-nitrobenzene) -6-dihydroxyboryzothiazole is prepared by:

4. Use of a compound according to claim 1 for the preparation of a compound that specifically binds to amyloid beta, wherein the compound that specifically binds to amyloid beta is 2- (4-methylaminobenzene) -6-dihydroxybenzothiazole; the 2- (4-methylamino benzene) -6-dihydroxy boron-based benzothiazole is prepared by the following method:

reacting the 2- (4-aminobenzene) -6-dihydroxy boronyl benzothiazole, methyl iodide and silver trifluoromethanesulfonate to generate 2- (4-methylaminobenzene) -6-dihydroxy boronyl benzothiazole; wherein the iodomethane passes through a silver trifluoromethanesulfonate tube which is heated to 200 ℃, and then reacts with the 2- (4-aminobenzene) -6-dihydroxy boron-based benzothiazole at the temperature of 80 ℃.