A fluoro-18 labeled p-aminophenylboronic acid, its preparation method and application

Abstract

This invention provides a fluoro-18 labeled p-aminophenylboronic acid, its preparation method, and its application. The fluoro-18 labeled p-aminophenylboronic acid is N-(4-phenylboronic acid)-2-D-fluorodeoxyglucosamine (4-N-[ 18 [F]FDGly-PBA). Among them, fluoro-18 labeled fluorodeoxyglucose can be used for tumor imaging, and p-aminophenylboronic acid can be used for BNCT treatment. Therefore, the fluoro-18 labeled p-aminophenylboronic acid provided by the present invention is a novel dual-targeted diagnostic and therapeutic imaging agent that can be used for tumor PET / CT imaging and BNCT treatment.

Description

Technical Field

[0001] This invention belongs to the fields of radiopharmaceutical chemistry and clinical nuclear medicine, and relates to... 18 F-labeled p-aminophenylboronic acid, its preparation method, and its application in PET / CT imaging and tumor treatment. Background Technology

[0002] In recent years, the incidence of cancer has been increasing year by year. How to diagnose and treat cancer early and improve patient survival rates has been a long-standing concern. Because positron emission tomography (PET / CT) can perform both anatomical and functional imaging, it is widely used in clinical practice and research. 18 F]-Fluorodeoxyglucose ([ 18 [F]-FDG) is its most commonly used imaging agent. Because its structure is similar to glucose, it can be taken up by the vast majority of tumor cells and is hailed as the "molecule of the century." However, [ 18 FDG, as a diagnostic imaging agent, cannot simultaneously provide therapeutic effects, making the development of novel therapeutic imaging agents a current research hotspot. Currently, tumor treatment primarily involves surgical resection, chemotherapy, and radiotherapy, each with its own advantages and disadvantages, and they are often used in combination. Traditional radiotherapy, due to its lack of targeting, can cause damage to normal tissue cells in the irradiated area to some extent. Boron neutron capture therapy (BNCT) is gradually gaining attention as a method of tumor radiotherapy. Compared to traditional radiotherapy, BNCT uses boron drugs that can accurately target tumor cells while having a lower distribution in normal cells. When thermal neutrons are absorbed by tumor cells... 10 B undergoes fission upon capture, producing highly destructive alpha particles and 7 Li recoils into the nucleus, thereby killing tumor cells. The concentration and metabolic rate of boron drugs in tumor and normal cells can affect the efficacy of tumor radiotherapy; however, boron drugs themselves cannot be quantitatively detected in vivo. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention aims to provide a fluorine-18 labeled p-aminophenylboronic acid, its preparation method, and its application. This fluorine-18 labeled p-aminophenylboronic acid has high chemical purity, good stability, and is simple to prepare. It is a novel diagnostic and therapeutic imaging agent that can be applied in the field of tumor positron emission tomography (PET).

[0004] This invention is achieved through the following technical solution:

[0005] A fluoro-18 labeled p-aminophenylboronic acid has the following structural formula:

[0006]

[0007] The method for preparing fluorine-18 labeled p-aminophenylboronic acid, using 2-[ 18 The reaction of F]F-fluorodeoxyglucose with p-aminophenylboronic acid yields fluoro-18-labeled p-aminophenylboronic acid.

[0008] The method for preparing fluorine-18 labeled p-aminophenylboronic acid includes the following steps:

[0009] S1, towards 2-[ 18 Acetonitrile was added to F]F-fluorodeoxyglucose injection, and 2-[ ] was removed by azeotropic drying under reduced pressure. 18 The water in F]F-fluorodeoxyglucose injection was used to obtain 2-[ 18 F]F-fluorodeoxyglucose acetonitrile solution;

[0010] S2, towards 2-[ 18 p-Aminophenylborate salt was added to F]F-fluorodeoxyglucose acetonitrile solution, and radiochemical labeling reaction was carried out under sealed conditions;

[0011] S3: The liquid obtained from the S2 reaction was purified by HPLC, then the acetonitrile was evaporated to dryness, physiological saline was added, and the solution was filtered through a sterile filter membrane to obtain fluorine-18 labeled p-aminophenylboronic acid injection.

[0012] Preferably, in S1, 2-[ 18 The ratio of the volume of F]F-fluorodeoxyglucose injection to the volume of acetonitrile is (0.5~1):(1~1.5).

[0013] Preferably, in S1, 2-[ 18 F]F-fluorodeoxyglucose injection 18 F activity ranges from 300 MBq to 700 MBq.

[0014] Preferably, in S2, the p-aminophenylborate salt is dissolved in methanol beforehand.

[0015] Preferably, in S2, the reaction temperature is 85℃~100℃ and the reaction time is 20min~25min.

[0016] Preferably, in S3, the HPLC purification uses an NH2 semi-preparative column and an acetonitrile-water solution as the mobile phase.

[0017] Preferably, in S3, the rotary evaporation temperature used to evaporate the acetonitrile is 40℃~50℃.

[0018] The application of the fluorine-18 labeled p-aminophenylboronic acid in the preparation of tumor PET or CT imaging agents.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention provides a fluoro-18 labeled p-aminophenylboronic acid, namely N-(4-phenylboronic acid)-2-D-fluorodeoxyglucosamine (4-N-[ 18 [F]FDGly-PBA). Among them, fluorine-18 labeled fluorodeoxyglucose can be used for tumor imaging, and p-aminophenylboronic acid can be used for BNCT treatment. Therefore, the fluorine-18 labeled p-aminophenylboronic acid provided by the present invention is a novel dual-targeted diagnostic and therapeutic imaging agent that can be used for tumor PET / CT imaging and BNCT treatment.

[0021] The method for preparing fluorine-18 labeled p-aminophenylboronic acid provided by this invention is simple, produces products with high chemical purity, and uses commercially available, widely sourced, and easily obtained chemical reagents. The 4-N-[ 18 F]FDGly-PBA has the characteristics of high chemical purity, good stability, high target / sample ratio, and long tumor retention time, and can be further applied to various types of tumor models. Attached Figure Description

[0022] Figure 1 This is a radiometric peak diagram of the crude product after the reaction in Example 1 was completed;

[0023] Figure 2 For standard product 4-N-[ 19 F]FDGly-PBA UV peak diagram;

[0024] Figure 3 4-N-[ 18 Radiometric peak diagram of F]FDGly-PBA;

[0025] Figure 4 4-N-[ 18 TLC spectrum of F]FDGly-PBA;

[0026] Figure 5 Micro-PET images of Bxpc-3 tumor-bearing nude mice at different time points;

[0027] Figure 6 The time-activity (TAC) curves at different time points in the tumor are shown. Detailed Implementation

[0028] To further understand the present invention, the present invention will be described below with reference to embodiments. These descriptions are only for further explaining the features and advantages of the present invention and are not intended to limit the claims of the present invention.

[0029] The fluorine-18 labeled p-aminophenylboronic acid of this invention has the molecular formula 4-N-[18 F]FDGly-PBA, its structural formula is as follows:

[0030]

[0031] This invention provides a method for preparing the above-mentioned fluorine-18 labeled p-aminophenylboronic acid, using radioactive 2-[ 18 F]-Fluorodeoxyglucose ([ 18 Radioactive fluorine-18 labeled p-aminophenylboronic acid was prepared by reacting fluorine-18 (F-FDG) with p-aminophenylboronic acid. The chemical reaction formula is as follows:

[0032]

[0033] The specific preparation process includes the following steps:

[0034] a. [ 18 [F]-FDG injection solution was placed in a sealed container, acetonitrile was added, and the solution was dried under reduced pressure using an azeotropic drying method to remove [F]. 18 Water content in F-FDG injection solution;

[0035] b. Then add p-aminophenylborate salt dissolved in methanol to the container, seal the container, and carry out radiochemical labeling under certain reaction conditions;

[0036] c. The liquid obtained in step b is purified by HPLC, then the mobile phase acetonitrile is evaporated to dryness, and finally 2 mL of physiological saline is added and filtered through a sterile filter membrane to obtain 4-N-[ 18 F]FDGly-PBA injection.

[0037] In step a, [ 18 The ratio of the volume of F-FDG injection solution to the total volume of acetonitrile is (0.5-1):(1-1.5), more preferably 1:1; 18 F]-FDG injection 18 F activity ranges from 300 MBq to 700 MBq.

[0038] In step b, the reaction temperature after the container is sealed is 85℃~100℃, more preferably 90℃; the reaction time is 20min~25min, more preferably 25min.

[0039] In step c, the HPLC mobile phase is acetonitrile / water = 3 / 1, the flow rate is 3 mL / min, and the chromatographic column is an NH2 semi-preparative column. The rotary evaporation temperature for drying the acetonitrile mobile phase is 40℃~50℃, more preferably 45℃.

[0040] The present invention obtains the liquid by aseptic filtration. 18 F-labeled p-aminophenylboronic acid. In this invention, the obtained... 18F-labeled p-aminophenylboronic acid was dispersed in physiological saline, and the solution contained... 18 F-labeled p-aminophenylboronic acid injection can be used directly as a PET / CT imaging agent.

[0041] Example 1

[0042] Preparation of 4-N-[ 18 The F]FDGly-PBA method is as follows:

[0043] Add 0.5 mL of 300 MBq of [ 18 F]-FDG injection solution was placed in a sealed container, and 1 mL of acetonitrile was added twice. The mixture was then azeotropically dried under negative pressure. Next, p-aminophenylborate acid salt dissolved in methanol was added to the container. After sealing the container, the reaction was carried out at 85°C for 20 min for radiochemical labeling. The radiometric peak diagram of the crude product is shown below. Figure 1 As shown. The reaction solution was directly purified by preparative high-performance liquid chromatography (HPLC). The preparative HPLC conditions were: amino chromatography semi-preparative column (250 mm × 10 mm), mobile phase acetonitrile / water = 3 / 1, 3 mL / min, UV = 254 nm. Figure 1 As shown, the fraction collected between 6 and 8 minutes was evaporated to dryness using a rotary evaporator at 45°C. Finally, 2 mL of physiological saline was added and the sample was filtered through a sterile membrane to obtain 4-N-[ 18 F]FDGly-PBA injection.

[0044] like Figure 4 As shown, 4-N-[ was determined using thin-layer chromatography (TLC). 18 The radiochemical purity of F]FDGly-PBA injection solution is 97%, and the radiochemical yield after decay correction is 25%.

[0045] Example 2

[0046] Add 1 mL of 700 MBq of [ 18 F]-FDG injection solution was placed in a sealed container, and 1.5 mL of acetonitrile was added twice. The mixture was azeotropically dried under negative pressure. Then, p-aminophenylborate acid salt dissolved in methanol was added to the container. The container was sealed and reacted at 100℃ for 25 min for radiochemical labeling. The reaction solution was directly purified by preparative high-performance liquid chromatography (HPLC). The preparative HPLC conditions were: amino chromatography semi-preparative column (250 mm × 10 mm), mobile phase acetonitrile / water = 3 / 1, 3 mL / min, UV = 254 nm. The fraction collected between 6 min and 8 min was evaporated to dryness with acetonitrile using a rotary evaporator at 50℃. Finally, 2 mL of physiological saline was added and the solution was filtered through a sterile membrane to obtain 4-N-[ 18 F]FDGly-PBA injection.

[0047] Example 3

[0048] Add 1 mL of 700 MBq of [ 18 F]-FDG injection solution was placed in a sealed container, and 1 mL of acetonitrile was added twice. The mixture was azeotropically dried under negative pressure. Then, p-aminophenylborate acid salt dissolved in methanol was added to the container. The container was sealed and reacted at 100℃ for 25 min for radiochemical labeling. The reaction solution was directly purified by preparative high-performance liquid chromatography (HPLC). The preparative HPLC conditions were: amino chromatography semi-preparative column (250 mm × 10 mm), mobile phase acetonitrile / water = 3 / 1, 3 mL / min, UV = 254 nm. The fraction collected between 6 min and 8 min was evaporated to dryness with acetonitrile using a rotary evaporator at 45℃. Finally, 2 mL of physiological saline was added and the solution was filtered through a sterile filter membrane to obtain 4-N-[ 18 F]FDGly-PBA injection.

[0049] Example 4

[0050] Preparation of standard 4-N- 19 The F-FDGly-PBA method is as follows:

[0051] Will 19 F-FDG (90 mg) was added to a 25 mL round-bottom flask, followed by p-aminophenylboronic acid (185 mg), methanol (10 mL), and acetic acid (1 mL). The mixture was reacted at 80 °C for 6 h. After the reaction was completed, the crude product was concentrated and passed through a chromatography column (DCM:MeOH = 150:1-100:1-80:1-60:1-40:1-30:1-10:1) to finally obtain the standard 4-N- 19 F-FDGly-PBA 3.6mg. 1 H NMR (400MHz, DMSO-d6) δ8.26 (s, 1H), 7.65 (s, 0H), 7.65-7.59 (m, 1H), 6.69-6.62 (m, 1H), 6.33 (dd, J = 6.7, 1.5Hz, 1H), 5. 26(ddd,J=11.1,6.7,5.1Hz,1H),4.63-4.53(m,1H),4.27(dd,J=5.6,3.5Hz,1H),4.10-3.89(m,1H),3.72-3.58(m,2H). ESI-MS(positive)m / z:301.11,C 12 H 17 BFNO6:302.1133[M+H] + . Figure 2 For standard product 4-N-[ 19 UV peak diagram of F]FDGly-PBA.

[0052] To identify the radioactive 4-N-[ synthesized in this invention] 18 The chemical structure of F]FDGly-PBA is used in this invention. 19 F substitute 18 F - A non-radioactive standard, 4-N-, was synthesized. 19 F-FDGly-PBA was used to identify the structure using NMR, and the structure was determined by standard 4-N- 19 F-FDGly-PBA and 4-N-[ 18 The HPLC retention time comparison of F]FDGly-PBA proved that the prepared 4-N-[ 18 The structure of F]FDGly-PBA is the structure described in this invention.

[0053] Application Example 1

[0054] Abnormal toxicity test: Three groups of healthy ICR mice, three mice in each group, were injected intravenously with 4-N-[ 18 F]FDGly-PBA injection (0.2 mL, 7 MBq), mice were fed routinely for 48 hours, and their growth was observed.

[0055] Mouse tail vein injection of 4-N-[ prepared in Example 1] 18 Following F]FDGly-PBA administration, no adverse reactions or deaths were observed 48 hours and one week later. Autopsy revealed no organ damage. Results indicate 4-N-[ 18 F]FDGly-PBA is non-toxic to the body and can be further used for in vivo research.

[0056] Application Example 2

[0057] Product stability test: 4-N-[ prepared in Example 1] 18 F]FDGly-PBA (1 mL, 37 MBq) was injected into the body via the tail vein of healthy ICR rats. After 5 min, urine was collected, filtered through an aqueous membrane, and the radiochemical purity was determined according to the above HPLC analysis conditions.

[0058] like Figure 3 As shown, the levels of 4-N-[ in the urine of healthy ICR rats were measured.] 18 The retention time of F]FDGly-PBA was approximately 6.3 min, with no impurity peaks appearing, indicating that the radioactive defluorination was not completed.

[0059] Application Example 3

[0060] In vivo biodistribution test: Six groups of healthy ICR mice, three mice per group, were injected via tail vein with 4-N-[ prepared in Example 1]. 18[F]FDGly-PBA (0.2 mL, 5 MBq) was injected. The animals were euthanized by neck dislocation at 5 min, 10 min, 30 min, 60 min, 90 min, and 120 min. Blood, heart, liver, lungs, kidneys, spleen, stomach, intestines, brain, muscles, and bones were dissected and collected. The tissues and organs were weighed and the radioactivity counts of the tissues or organs were measured. After decay correction, the percentage injection dose rate (%ID / g) per gram of tissue was calculated. The results are shown in Table 1.

[0061] Overall, this 4-N-[ 18 After injection of the FDGly-PBA imaging agent into mice, various organs showed some uptake, with the most significant uptake in the kidneys, followed by some uptake in the liver. The agent then concentrated in the gallbladder and was excreted slowly, leaving a certain amount of radioactive residue at 120 minutes. The brain showed relatively low radioactive uptake at all time points, suggesting that 4-N-[ 18 F]FDGly-PBA may be helpful in detecting lesions in this area. There was mild radioactive uptake in the bone, but the uptake value did not change significantly over time, suggesting that defluorination had not occurred in the body and that the uptake was physiological.

[0062] Table 1 4-N-[ 18 Biodistribution of F]FDGly-PBA in healthy ICR mice (%ID / g, n=3)

[0063]

[0064] Application Example 4

[0065] Micro-PET imaging: Bxpc-3 tumor-bearing nude mice were anesthetized with 2% isoflurane gas and then fixed in a Minerve rat animal chamber (Minerve Vétérinaire, Esternay, France) at a constant temperature of 37°C to maintain a constant body temperature. Simultaneously, the animals were anesthetized by inhalation of a mixture of air and 2% isoflurane gas at a rate of 2.5 L / min. Subsequently, they were injected via tail vein with 4-N-[…] prepared in Example 1. 18 [F]FDGly-PBA (0.5 mL, 7 MBq) was administered, and dynamic image acquisition was performed for 120 min. Image reconstruction was performed using the 3D Ordered Subsets Expectation Maximization (OSEM) algorithm based on the Monte Carlo system model. Image analysis was performed using PMOD software (PMOD Technologies LLC, Zurich, Switzerland) to delineate the volume of interest (VOI).

[0066] Figure 5 It can be seen that the injection of 4-N-[18 Five minutes after F]FDGly-PBA injection, the tumor began to show up with relatively clear boundaries. The liver and urinary system also showed high radioactive uptake, while other tissues and organs showed lower uptake. Thirty minutes after injection, significant radioactive uptake was observed in the gallbladder, while liver radioactivity decreased significantly. Whether this is helpful in diagnosing liver tumors and gallbladder-negative stones requires further experimental verification. Brain tissue and bone showed relatively low radioactive uptake at all time points. Figure 6 As shown, the tumor radioactive uptake rate reached its maximum at 10 minutes and gradually decreased over time. At 120 minutes, there was still a certain amount of radioactive residue, suggesting that it can be used for BNCT treatment.

Claims

1. A fluorine-18 labeled p-aminophenylboronic acid, characterized in that, The structural formula is as follows:

2. The method of claim 1, wherein the preparation of fluoro-18 labeled p-aminophenylboronic acid is characterized by, 2-[ 18 F]F-fluorodeoxyglucose and p-aminobenzoic acid to produce fluorine-18 labeled p-aminobenzoic acid.

3. The method of claim 2, wherein the method is characterized by, The method comprises the following steps: S1, to 2-[ 18 F]F-deoxyglucose injection is added acetonitrile, and the water in the 2-[ 18 F]F-deoxyglucose injection is removed by a method of vacuum azeotropic drying to obtain a 2-[ 18 F]F-deoxyglucose acetonitrile solution. S2, to 2-[ 18 F]F-deoxyglucose acetonitrile solution, and the radiochemical labeling reaction was carried out under sealing conditions; S3, purifying the liquid obtained in S2 by HPLC, then evaporating acetonitrile, adding physiological saline and filtering through a sterile filter membrane to obtain a fluorine-18 labeled p-aminobenzoic acid injection.

4. The method of claim 3, wherein the method is characterized by, In S1, 2-[ 18 The ratio of the volume of F]F-fluorodeoxyglucose injection to the volume of acetonitrile is (0.5-1) : (1-1.5).

5. The method of claim 3, wherein the method is characterized by, In S1, 2-[ 18 F]F-fluorodeoxyglucose injection 18 Factivity is 300 MBq ~ 700 MBq.

6. The method of claim 3, wherein the method is characterized by, In S2, the p-aminobenzoic acid hydrochloride is dissolved in advance with methanol.

7. The method of claim 3, wherein the method is characterized by, In S2, the reaction temperature is 85-100 DEG C, and the reaction time is 20-25 min.

8. The method of claim 3, wherein the method is characterized by, In S3, the HPLC purification adopts an NH2 chromatographic semi-preparative column, and the mobile phase is an acetonitrile-water solution.

9. The method of claim 3, wherein the method is characterized by, In S3, the rotary evaporation temperature for evaporating acetonitrile is 40-50 DEG C.

10. Use of the fluorine-18 labeled p-aminobenzoic acid of claim 1 in the preparation of a tumor PET or CT diagnosis and treatment integrated imaging agent.

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