EphA2 receptor-targeted PET (Polyethylene Terephthalate) imaging agent, labeled precursor and preparation method and application of EphA2 receptor-targeted PET imaging agent

Abstract

The invention discloses a PET (positron emission tomography) imaging agent, a precursor and a probe for targeting an EphA2 receptor as well as a preparation method and application of the PET imaging agent, the precursor and the probe, and a radioactive probe which is formed by labeling a chelating agent (such as DOTA and NOTA) and a radionuclide (such as 68Ga) by taking bicyclic peptide as a targeting group is specifically combined with the EphA2 receptor highly expressed on the surface of a tumor cell. According to the invention, a conformation limitation strategy is adopted for transforming the peptide probe targeting EphA2 for the first time, the bicyclic peptide radioactive probe with excellent targeting performance and in-vivo imaging effect is obtained, the tumor uptake value is high, and tumor and non-tumor imaging is clear; and successful imaging in a fibrosarcoma model. According to the EphA2 receptor-targeted PET imaging agent provided by the invention, the precursor, namely the probe, has the advantages of simplicity in preparation, good targeting property, excellent imaging effect and the like, can be used for PET imaging diagnosis, prognosis evaluation and targeted therapy guidance of EphA2 positive tumors, and has good clinical value.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to PET imaging agents, labeling precursors, preparation methods, and applications targeting the EphA2 receptor. Background Technology

[0002] Malignant tumors are among the major diseases that seriously threaten human health. Accurate diagnosis and effective treatment are key to improving the survival rate and quality of life for cancer patients. Molecular imaging technologies, especially positron emission tomography (PET), can visualize the biological characteristics of tumors at the molecular level by using specific targeted molecular probes, providing a powerful tool for early detection, staging, treatment evaluation, and prognosis of tumors.

[0003] EphA2 (Ephreceptor A2) is a transmembrane protein belonging to the tyrosine kinase receptor family, playing a crucial regulatory role in embryonic development, angiogenesis, and cell localization. EphA2 and its ligand Ephrin-A1 constitute the Eph-ephrin signaling pathway. While its expression levels are low in normal tissues, it is significantly high in various malignant tumors (such as breast cancer, pancreatic cancer, prostate cancer, non-small cell lung cancer, and fibrosarcoma). Studies have shown that EphA2 overexpression not only promotes tumor cell migration, invasion, and metastasis but is also closely associated with poor prognosis.

[0004] Due to its specific expression in various tumor tissues and its crucial role in tumorigenesis and development, EphA2 is considered a molecular imaging and targeted therapy target with potential for clinical translation. In recent years, monoclonal antibodies, inhibitors, and CAR-T cell therapies targeting EphA2 have all shown promising applications in cutting-edge research.

[0005] Radioligands targeting EphA2 can be used in positron emission tomography (PET) to achieve precise molecular imaging diagnosis of tumors, aiding in lesion localization, classification, and efficacy evaluation. However, there is currently a lack of PET probes with good affinity for EphA2, high in vivo stability, and strong specificity. Existing EphA2-targeting agents suffer from problems such as poor tissue penetration, rapid metabolic clearance, high background signal, easy enzymatic degradation in vivo, and potentially insufficient target affinity and specificity due to high conformational flexibility, as well as the possibility of non-specific uptake, limiting their widespread application in clinical molecular imaging.

[0006] Therefore, developing novel EphA2-targeting radioactive probes with higher stability, stronger target affinity, better in vivo pharmacokinetic properties, and better imaging effects is of great clinical significance and application value for improving the accuracy of diagnosis of EphA2-positive tumors. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies and improve the targeting selectivity, affinity, and biological stability of bicyclic peptide probes targeting EphA2, this invention provides the following technical solutions:

[0008] A first aspect of the present invention provides a PET imaging agent targeting the EphA2 receptor, the structure of which is shown in Formula X below:

[0009]

[0010] Wherein, R1 is selected from any one or more of the following groups 1, 2, and 3:

[0011]

[0012] Or a pharmaceutically acceptable salt thereof, where n is an integer selected from 1 to 12;

[0013] Furthermore, the PET imaging agent targeting the EphA2 receptor has the structure shown in Formula I, II, or III as follows:

[0014]

[0015]

[0016] Or a pharmaceutically acceptable salt thereof, wherein in formulas I to III, n is an integer selected from 1 to 12;

[0017] A second aspect of the present invention provides a PET imaging agent precursor targeting the EphA2 receptor, the structure of which is shown in Formula XI:

[0018]

[0019] Wherein, R2 is selected from any one or more of the following groups 4, 5, and 6:

[0020]

[0021] Or a pharmaceutically acceptable salt thereof, where n is an integer selected from 1 to 12;

[0022] Furthermore, the PET developer precursor has the structure shown in formula IV, V, or VI below:

[0023]

[0024] Or its pharmaceutically acceptable salt;

[0025] A third aspect of the present invention provides a method for preparing any of the above-mentioned EphA2 receptor-targeted PET imaging agent precursors, comprising the following steps:

[0026] Compound G was dissolved in a trifluoroacetic acid (TFA) solution, and the mixture was stirred at room temperature until the reaction was complete. Then, ether was added for washing, and the mixture was vacuum filtered to obtain the PET developer precursor. The structure of compound G is shown in formula XII below:

[0027]

[0028] Wherein, R3 is selected from any one or more of the following groups 7, 8, and 9:

[0029]

[0030] Furthermore, the structure of compound G is shown in formula VII, VIII, or IX:

[0031]

[0032]

[0033] Further, the concentration of the TFA is 80-100 v / v%; more preferably, the concentration of the TFA is 90 v / v%.

[0034] Furthermore, the preparation method of compound G includes the following steps:

[0035] S1: Sequentially add compound Boc-(SAR) 10- Ala-COOH or the compound Boc-(PEG) 8- Ala-COOH), 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, and N,N-diisopropylethylamine were dissolved in anhydrous DMF. After stirring at room temperature, the bicyclic peptide was added, and the mixture was stirred at room temperature until the reaction was complete. A saturated NaHCO3 solution was added, and the mixture was extracted with ethyl acetate. The organic phases were combined and then dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain compound A, which was a solid powder. Further, the molar ratio of Boc-(SAR)10-Ala-COOH or Boc-(PEG)8-Ala-COOH:2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate:N,N-diisopropylethylamine:bicyclic peptide was 1.2-2:1.2-2:2.5-3:1. Even further, Boc-(SAR) 10- Ala-COOH or Boc-(PEG) 8- The molar ratio of Ala-COOH: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine: bicyclic peptide is 1.3:1.3:2.6:1;

[0036] Furthermore, the bicyclic peptide structure is shown below:

[0037]

[0038] S2: Add compound A to a TFA-dichloromethane solution with a volume percentage of 40-60%, stir at room temperature until the reaction is complete, concentrate under reduced pressure, wash with diethyl ether, and filter under vacuum to obtain compound B;

[0039] S3: Compound B was dissolved in anhydrous DMF with compounds Boc-3-(2-naphthyl)-L-alanine, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, and N,N-diisopropylethylamine. The mixture was stirred at room temperature until the reaction was complete. A saturated NaHCO3 solution was then added, followed by extraction with ethyl acetate. The organic phases were combined and successively dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified to obtain compound C, which was a solid powder. Further, the compound... Compound B: The molar ratio of Boc-3-(2-naphthalene)-L-alanine: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.2-2:1.2-2:2.5-3; furthermore, the molar ratio of compound B: Boc-3-(2-naphthalene)-L-alanine: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.3:1.3:2.6;

[0040] S4: Add compound C to a TFA-dichloromethane solution with a volume percentage of 40-60%, stir at room temperature until the reaction is complete, concentrate under reduced pressure, wash with diethyl ether, and filter under vacuum to obtain compound D;

[0041] S5: Compound D, compound BOC-tranexamic acid, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, and N,N-diisopropylethylamine were dissolved in anhydrous DMF and stirred at room temperature until the reaction was complete. Then, saturated NaHCO3 solution was added, and the mixture was extracted with ethyl acetate. The organic phases were combined and successively dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified to obtain compound E, which was a solid powder. Further, the molar ratio of compound D: BOC-tranexamic acid: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine was 1:1.2–3:1.2–2:2.5–3. Even further, the molar ratio of compound D: BOC-tranexamic acid: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine was 1:1.2–3:1.2–2:2.5–3.

[0042] The molar ratio of (-N,N,N',N'-tetramethylurea hexafluorophosphate to N,N-diisopropylethylamine is 1:1.3:1.3:2.6.

[0043] S6: Add compound E to a TFA-dichloromethane solution with a volume percentage of 40-60%, stir at room temperature until the reaction is complete, concentrate under reduced pressure, wash with diethyl ether, and filter under vacuum to obtain compound F;

[0044] S7: Compound F, compound DOTA-(COOt-Bu)3 or compound Nota-(COOt-Bu)2, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate and N,N-diisopropylethylamine were dissolved in anhydrous DMF and stirred at room temperature until the reaction was complete. A saturated NaHCO3 solution was added, and the mixture was extracted with ethyl acetate. The organic phases were combined and dried sequentially through anhydrous Na2SO4. After filtration and concentration under reduced pressure, a crude product was obtained. The crude product was purified to give compound G, which was a solid powder. Further, compound F: compound DOT The molar ratio of A-(COOt-Bu)3 or NOTA-(COOt-Bu)2: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.2~2:1.2~2:2.5~3; furthermore, the molar ratio of compound F: compound DOTA-(COOt-Bu)3 or NOTA-(COOt-Bu)2: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.3:1.3:2.6;

[0045] A fourth aspect of the present invention provides a PET imaging agent probe targeting the EphA2 receptor, obtained by radiolabeling any of the above-mentioned PET imaging agents;

[0046] Furthermore, the radioactive element is 68 Ga;

[0047] The fifth aspect of the present invention provides a method for preparing any of the above-mentioned PET imaging agent probes targeting the EphA2 receptor, comprising the following steps:

[0048] Will 68 The GaCl3 eluent was mixed with the PET imaging agent precursor solution and reacted at 90-100℃ for 8-12 min. After cooling to room temperature, the mixture was diluted with water and separated using a C-18 column. The eluent was eluted with a 60-80 v / v% ethanol aqueous solution and concentrated to dryness to obtain the PET imaging agent probe solution targeting the EphA2 receptor.

[0049] Furthermore, the aforementioned 68The preparation method of GaCl3 rinsing solution includes the following steps: injecting 0.1M hydrochloric acid solution into a germanium-gallium generator for rinsing to obtain... 68 The reaction solution was rinsed with GaCl3, and then sodium acetate solution was added to adjust the pH of the system to 4.0-4.2.

[0050] Furthermore, the PET developer solution is 68 Ga-DOTA-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68 Ga-DOTA-FZ-BT508-3 solution;

[0051] The fifth aspect of the present invention provides the use of any of the above-mentioned PET imaging agents targeting the EphA2 receptor or PET imaging agent probes targeting the EphA2 receptor in the preparation of diagnostic reagents for EphA2 protein-related diseases or conditions.

[0052] Furthermore, the diseases or conditions associated with the EphA2 protein include tumors or inflammation;

[0053] Furthermore, the tumors include fibrosarcoma, breast cancer, pancreatic cancer, and prostate cancer;

[0054] A sixth aspect of the present invention provides a pharmaceutical composition comprising any of the above-described PET imaging agents targeting the EphA2 receptor or PET imaging agent probes targeting the EphA2 receptor and their pharmaceutically acceptable carriers.

[0055] A seventh aspect of the present invention provides a kit comprising any of the above-described PET imaging agents targeting the EphA2 receptor or PET imaging agent probes targeting the EphA2 receptor.

[0056] Beneficial effects

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] (1) Innovative Molecular Design: This patent innovatively employs a conformational constraint strategy to modify bicyclic peptides. By introducing a rigid scaffold structure, the degree of conformational freedom of the molecular structure is effectively reduced, thereby locking the peptide sequence into a specific conformation with optimal biological activity, significantly enhancing the recognition efficiency and binding ability to the target protein EphA2. Specifically, this patent introduces a rigid conformational scaffold containing a naphthylurea structural unit ((S)-4-((3-(naphtho[1,2-d]oxazol-2-yl)phenyl)ureoyl)-N-((S)-cyclohexylmethyl)cyclohexaneformamide) to ensure the stability of the cyclic peptide structure in a dynamic environment. This rigid scaffold effectively restricts the conformational flexibility of the peptide molecule, allowing the peptide sequence to be precisely located in the ideal biologically active conformation, thereby improving the selectivity and affinity for targeting EphA2, prolonging the in vivo half-life, and enhancing the clinical translation potential of the probe.

[0059] (2) Excellent targeting and imaging performance: The series of probes provided by this invention (such as...) 68 Ga-FZ-BT508-1 / 2 / 3) exhibited good targeting of the EphA2 receptor both in vitro and in vivo. Animal PET imaging studies showed that this series of probes could rapidly and highly accumulate in tumor models with high EphA2 expression (HT1080), producing clear tumor images with relatively low background tissue uptake and a good tumor / non-target tissue ratio. In particular... 68 Ga-DOTA-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68 Ga-DOTA-FZ-BT508-3 exhibited the best tumor uptake and imaging performance.

[0060] (3) Rapid in vivo dynamics: The probe can reach a high uptake peak at the tumor site within a short time after injection (e.g., 0.5-1 hour), which meets the requirements of clinical PET imaging for rapid probe clearance and targeted enrichment.

[0061] (4) The preparation is relatively simple: the synthesis and radiolabeling steps of the probe precursor are relatively mature and reliable, the labeling efficiency is high, it is easy to prepare, and it is suitable for clinical application.

[0062] (5) Wide Applicability: Aberrant expression of EphA2 protein is common in various solid tumors, providing a precise diagnostic and assessment tool for patients with various types of tumors (including but not limited to fibrosarcoma, breast cancer, pancreatic cancer, and prostate cancer). It enables qualitative diagnosis of EphA2 in tumors, followed by non-invasive and precise quantification of EphA2 in tumors, providing reliable evidence for clinical staging, treatment decisions, and efficacy monitoring, ultimately achieving precision medicine.

[0063] In summary, this invention provides a novel, efficient, and highly specific bicyclic peptide radioactive probe targeting the EphA2 receptor, offering a promising new tool for the precise diagnosis of EphA2-positive tumors (especially breast cancer and fibrosarcoma). Attached Figure Description

[0064] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0065] Figure 1 The mass spectrum of DOTA-FZ-BT508-1, a PET imaging agent precursor;

[0066] Figure 2 The mass spectrum of the PET imaging agent precursor NOTA-FZ-BT508-2;

[0067] Figure 3 The mass spectrum of DOTA-FZ-BT508-3, a PET imaging agent precursor;

[0068] Figure 4 Radioactive probe 68 Radio-HPLC spectrum of Ga-DOTA-FZ-BT508-1;

[0069] Figure 5 Radioactive probe 68 Radio-HPLC spectrum of Ga-NOTA-FZ-BT508-2;

[0070] Figure 6 Radioactive probe 68 Radio-HPLC spectrum of Ga-DOTA-FZ-BT508-3;

[0071] Figure 7 SPR affinity spectrum of PET developer DOTA-FZ-BT508-1;

[0072] Figure 8 SPR affinity spectrum of PET developer NOOTA-FZ-BT508-2;

[0073] Figure 9 SPR affinity spectrum of PET developer DOTA-FZ-BT508-3;

[0074] Figure 10 Radioactive probe 68The lipid-water partition coefficient of Ga-DOTA-FZ-BT508-1;

[0075] Figure 11 Radioactive probe 68 The lipid-water partition coefficient of Ga-NOTA-FZ-BT508-2;

[0076] Figure 12 Radioactive probe 68 The lipid-water partition coefficient of Ga-DOTA-FZ-BT508-3;

[0077] Figure 13 Radioactive probe 68 Stability of Ga-DOTA-FZ-BT508-1 in physiological saline;

[0078] Figure 14 Radioactive probe 68 Stability of Ga-NOTA-FZ-BT508-2 in physiological saline;

[0079] Figure 15 Radioactive probe 68 Stability of Ga-DOTA-FZ-BT508-3 in physiological saline;

[0080] Figure 16 Radioactive probe 68 Stability of Ga-DOTA-FZ-BT508-1 in human serum;

[0081] Figure 17 Radioactive probe 68 Stability of Ga-NOTA-FZ-BT508-2 in human serum;

[0082] Figure 18 Radioactive probe 68 Stability of Ga-DOTA-FZ-BT508-3 in human serum;

[0083] Figure 19 Radioactive probe 68 PET imaging study of Ga-DOTA-FZ-BT508-1;

[0084] Figure 20 Radioactive probe 68 PET imaging study of Ga-NOTA-FZ-BT508-2;

[0085] Figure 21 Radioactive probe 68 PET Imaging Study of Ga-DOTA-FZ-BT508-3 Detailed Implementation

[0086] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0087] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0088] Example 1: Preparation of a PET imaging agent targeting the EphA2 receptor:

[0089] All reagents used in this invention can be purchased commercially or prepared by the methods described in this invention.

[0090] 1.1 The synthetic route of compound DOTA-FZ-BT508-1 (i.e., PET developer precursor) is shown below:

[0091]

[0092] (1) Synthesis of compound A

[0093] In a 50 mL pear-shaped flask, compound Boc-(SAR) was added sequentially. 10 -Ala-COOH (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved in 5 mL of anhydrous DMF. After stirring the reaction mixture at room temperature, the bicyclic peptide BT508 (1 eq) was added, and the mixture was stirred overnight at room temperature. After the reaction was completed by TLC monitoring, the organic phases were combined. The organic phases were then dried over anhydrous Na₂SO₄, filtered, concentrated under reduced pressure, and the crude product was purified to obtain compound A as a solid powder.

[0094] (2) Synthesis of compound B

[0095] In a 50 mL round-bottom flask, compound A (1 eq) was added and dissolved in 5 mL of 50% TFA solution (TFA / DCM = 1:1, v / v). The reaction system was stirred at room temperature for 3 h, and the reaction progress was monitored by TLC until completion. The reaction system was concentrated under reduced pressure, washed with diethyl ether, and filtered under vacuum to remove the remaining trifluoroacetic acid, yielding compound B.

[0096] (3) Synthesis of compound C

[0097] In a 50 mL round-bottom flask, compounds Boc-3-(2-Naphthyl)-L-alanine (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved in 7 mL of anhydrous DMF. After stirring the reaction system at room temperature for 0.5 h, compound B (1 eq) dissolved in 3 mL of anhydrous DMF was added to the reaction system, and the reaction system was stirred overnight at room temperature. After the reaction progress was monitored by TLC, saturated NaHCO3 solution (2 × 30 mL) was added to the reaction system, followed by extraction with EA (3 × 50 mL), and the organic phases were combined. The organic phases were dried over anhydrous Na2SO4, filtered, concentrated under reduced pressure, and the crude product was purified to obtain compound C as a solid powder.

[0098] (4) Synthesis of compound D

[0099] In a 50 mL round-bottom flask, compound C (1 eq) was added and dissolved in 5 mL of 50% TFA solution (TFA / DCM = 1:1, v / v). The reaction system was stirred at room temperature for 3 h, and the reaction progress was monitored by TLC until the reaction was complete. The reaction system was concentrated under reduced pressure, washed with diethyl ether, and filtered under vacuum to remove the remaining trifluoroacetic acid, yielding compound D.

[0100] (5) Synthesis of compound E

[0101] In a 50 mL round-bottom flask, compounds BOC-TRANEXAMIC ACID (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved sequentially in 7 mL of anhydrous DMF. After stirring the reaction system at room temperature for 0.5 h, compound D (1 eq) dissolved in 3 mL of anhydrous DMF was added to the reaction system, and the system was stirred overnight at room temperature. After the reaction was completed by TLC monitoring, saturated NaHCO3 solution (2 × 30 mL) was added to the reaction system, followed by extraction with EA (3 × 50 mL), and the organic phases were combined. The organic phases were dried over anhydrous Na2SO4, filtered, concentrated under reduced pressure, and the crude product was purified to obtain compound E as a solid powder.

[0102] (6) Synthesis of compound F

[0103] In a 50 mL round-bottom flask, compound E (1 eq) was added and dissolved in 5 mL of 50% TFA solution (TFA / DCM = 1:1, v / v). The reaction system was stirred at room temperature for 3 h, and the reaction progress was monitored by TLC until the reaction was complete. The reaction system was concentrated under reduced pressure, washed with diethyl ether, and filtered under vacuum to remove the remaining trifluoroacetic acid, yielding compound F.

[0104] (7) Synthesis of compound G

[0105] In a 50 mL round-bottom flask, compounds DOTA-(COOt-Bu)3 (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved in 7 mL of anhydrous DMF. After stirring the reaction system at room temperature for 0.5 h, compound F (1 eq) dissolved in 3 mL of anhydrous DMF was added to the reaction system, and the reaction system was stirred overnight at room temperature. After the reaction progress was monitored by TLC, saturated NaHCO3 solution (2 × 30 mL) was added to the reaction system, followed by extraction with EA (3 × 50 mL), and the organic phases were combined. The organic phases were dried over anhydrous Na2SO4, filtered, concentrated under reduced pressure, and the crude product was purified to obtain compound G as a solid powder.

[0106] (8) Synthesis of PET developer labeling precursor compound Nota-FZ-BT508-1

[0107] In a 50 mL round-bottom flask, compound G (1 eq) was dissolved in 5 mL of 90% TFA solution (TFA / DCM = 9:1, v / v). The reaction system was stirred at room temperature for 2 h. After the reaction was completed, the reaction system was concentrated under reduced pressure, washed with diethyl ether, and vacuum filtered to remove the remaining trifluoroacetic acid to obtain the PET developer precursor NOTA-FZ-BT508-1.

[0108] MS-ESI(+) calculated for C 176 H 267 N 49 O 47 S3:3917.5480,[M] / 3+1found:1306.7,[M] / 4+1found:980.6,[M] / 5+1found:784.7.

[0109] The mass spectrum and HPLC spectrum of the PET imaging agent-labeled precursor compound DOTA-FZ-BT508-1 targeting the EphA2 receptor are shown below. Figure 1 and Figure 4 As shown.

[0110] 1.2 The synthetic route of compound Nota-FZ-BT508-2 (i.e., PET developer precursor) is shown below:

[0111]

[0112] (1) Synthesis of compound G

[0113] In a 50 mL round-bottom flask, compounds NOTA-(COOt-Bu)2 (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved in 7 mL of anhydrous DMF. After stirring the reaction system at room temperature for 0.5 h, compound F (1 eq) dissolved in 3 mL of anhydrous DMF was added to the reaction system, and the reaction system was stirred overnight at room temperature. After the reaction progress was monitored by TLC, saturated NaHCO3 solution (2 × 30 mL) was added to the reaction system, followed by extraction with EA (3 × 50 mL), and the organic phases were combined. The organic phases were dried over anhydrous Na2SO4, filtered, concentrated under reduced pressure, and the crude product was purified to obtain compound G as a solid powder.

[0114] (2) Synthesis of PET developer labeling precursor compound Nota-FZ-BT508-2

[0115] In a 50 mL round-bottom flask, compound G (1 eq) was dissolved in 5 mL of 90% TFA solution (TFA / DCM = 9:1, v / v). The reaction system was stirred at room temperature for 2 h. After the reaction was completed, the reaction system was concentrated under reduced pressure, washed with diethyl ether, and the remaining trifluoroacetic acid was removed by vacuum filtration to obtain the PET developer precursor NOTA-FZ-BT508-2.

[0116] MS-ESI(+) calculated for C 172 H 260 N 48 O 45 S3:3813.8694,[M] / 3+1found:1273.0,[M] / 4+1found:955.3,[M] / 5+1found:764.3.

[0117] The mass spectrum and HPLC spectrum of the PET imaging agent-labeled precursor compound NOTA-FZ-BT508-2 targeting the EphA2 receptor are shown below. Figure 2 and Figure 5 As shown.

[0118] 1.3 The synthetic route of compound DOTA-FZ-BT508-3 (i.e., PET developer precursor) is shown below:

[0119] (1) Synthesis of Compound I

[0120]

[0121] In a 50 mL round-bottom flask, compounds Boc-(PEG)9-Ala-COOH (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved sequentially in 5 mL of anhydrous DMF. After stirring the reaction mixture at room temperature, the bicyclic peptide BT508 (1 eq) was added, and the mixture was stirred overnight at room temperature. After the reaction was completed by TLC monitoring, the organic phases were combined. The organic phases were then dried over anhydrous Na₂SO₄, filtered, concentrated under reduced pressure, and the crude product was purified to obtain compound I as a solid powder.

[0122] (2) Synthesis of compound J

[0123] In a 50 mL round-bottom flask, compound I (1 eq) was added and dissolved in 5 mL of 50% TFA solution (TFA / DCM = 1:1, v / v). The reaction system was stirred at room temperature for 3 h, and the reaction progress was monitored by TLC until the reaction was complete. The reaction system was concentrated under reduced pressure, washed with diethyl ether, and filtered under vacuum to remove the remaining trifluoroacetic acid, yielding compound J.

[0124] (3) Synthesis of compound K

[0125] In a 50 mL round-bottom flask, compounds Boc-3-(2-Naphthyl)-L-alanine (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved in 7 mL of anhydrous DMF. The reaction mixture was stirred at room temperature for 0.5 h. Then, compound J (1 eq), dissolved in 3 mL of anhydrous DMF, was added to the reaction mixture, and the mixture was stirred overnight at room temperature. After the reaction was completed by TLC monitoring, saturated NaHCO3 solution (2 × 30 mL) was added to the reaction mixture, followed by extraction with EA (3 × 50 mL). The organic phases were combined. The organic phases were dried over anhydrous Na2SO4, filtered, concentrated under reduced pressure, and purified to obtain a solid powder compound K.

[0126] (4) Synthesis of compound L

[0127] In a 50 mL round-bottom flask, compound K (1 eq) was added and dissolved in 5 mL of 50% TFA solution (TFA / DCM = 1:1, v / v). The reaction system was stirred at room temperature for 3 h, and the reaction progress was monitored by TLC until completion. The reaction system was concentrated under reduced pressure, washed with diethyl ether, and filtered under vacuum to remove the remaining trifluoroacetic acid, yielding compound L.

[0128] (5) Synthesis of compound M

[0129] In a 50 mL round-bottom flask, compounds BOC-TRANEXAMIC ACID (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved sequentially in 7 mL of anhydrous DMF. After stirring the reaction system at room temperature for 0.5 h, compound L (1 eq) dissolved in 3 mL of anhydrous DMF was added to the reaction system, and the reaction system was stirred overnight at room temperature. After the reaction progress was monitored by TLC, saturated NaHCO3 solution (2 × 30 mL) was added to the reaction system, followed by extraction with EA (3 × 50 mL), and the organic phases were combined. The organic phases were dried sequentially through anhydrous Na2SO4, filtered, concentrated under reduced pressure, and the crude product was purified to obtain a solid powder compound M.

[0130] (6) Synthesis of compound N

[0131] In a 50 mL round-bottom flask, compound M (1 eq) was added and dissolved in 5 mL of 50% TFA solution (TFA / DCM = 1:1, v / v). The reaction system was stirred at room temperature for 3 h, and the reaction progress was monitored by TLC until completion. The reaction system was concentrated under reduced pressure, washed with diethyl ether, and filtered under vacuum to remove residual trifluoroacetic acid, yielding compound N.

[0132] (7) Synthesis of compound O

[0133] In a 50 mL round-bottom flask, compounds DOTA-(COOt-Bu)3 (1.3 eq), HATU (1.3 eq), and DIPEA (2.6 eq) were dissolved in 7 mL of anhydrous DMF. After stirring the reaction system at room temperature for 0.5 h, compound N (1 eq) dissolved in 3 mL of anhydrous DMF was added to the reaction system, and the reaction system was stirred overnight at room temperature. After the reaction progress was monitored by TLC, saturated NaHCO3 solution (2 × 30 mL) was added to the reaction system, followed by extraction with EA (3 × 50 mL), and the organic phases were combined. The organic phases were dried over anhydrous Na2SO4, filtered, concentrated under reduced pressure, and the crude product was purified to obtain a solid powder of compound O.

[0134] (8) Synthesis of DOTA-FZ-BT508-3, a PET developer labeling precursor compound

[0135] In a 50 mL round-bottom flask, compound O (1 eq) was dissolved in 5 mL of 90% TFA solution (TFA / DCM = 9:1, v / v). The reaction system was stirred at room temperature for 2 h. After the reaction was completed, the reaction system was concentrated under reduced pressure, washed with diethyl ether, and vacuum filtered to remove the remaining trifluoroacetic acid to obtain the PET developer precursor DOTA-FZ-BT508-3.

[0136] MS-ESI(+) calculated for C165 H 254 N 40 O 46 S3:3627.7928,[M] / 3+1found:1211.1,[M] / 4+1found:908.4,[M] / 5+1found:727.3.

[0137] The mass spectrum and HPLC spectrum of the PET imaging agent-labeled precursor compound DOTA-FZ-BT508-3 targeting the EphA2 receptor are shown below. Figure 3 and Figure 6 As shown.

[0138] Example 2: Compound 68 Ga-DOTA-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68 Preparation of Ga-DOTA-FZ-BT508-3

[0139] from 68 Ge- 68 4 mL was obtained by rinsing in the Ga generator. 68 GaCl3 eluent was added sequentially with 50 μL of precursor (1 mg / mL) solution and 0.375 mL of NaOAc (1.5 M) solution. The reaction system was incubated at 90–100 °C for 10 min, then cooled to room temperature. The labeled system was diluted with 12 mL of sterile water and then passed through a C1 filter. 18 Column (SEP-PAK), product adsorption onto C 18 Column, inject 1.5 mL of ethanol-water solution (V) 乙醇 :V 水 =70% / 30%) will transfer the product from C 18 Column elution yields the final product. 68 Ga-DOT A-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68 Ga-DOTA-FZ-BT508-3 (i.e., PET developer). The product was evaluated by radio-TLC (developer volume ratio of NH4OAc(1M) / MeOH = 1 / 1) and radio-HPLC.

[0140] See results Figure 4 As shown, after purification 68 The radiochemical purity of Ga-DOTA-FZ-BT508-1 is greater than 97%; see Figure 5 As shown, after purification 68The radiochemical purity of Ga-NOTA-FZ-BT508-2 is greater than 97%; see Figure 6 As shown, after purification 68 The radiochemical purity of Ga-DOTA-FZ-BT508-3 is greater than 97%, which meets the subsequent biological and imaging evaluation standards.

[0141] Example 3: Compound 68 Ga-DOTA-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68 Affinity of Ga-DOTA-FZ-BT508-3 precursor

[0142] This study used the BIAcore T200 molecular interaction analysis system (catalog number: 2844878, Cytiva) to evaluate the binding kinetics between the EphA2 radioactive probe precursor and the target protein. The Series Sensor Chip NTA chip (catalog number: BR100532, Cytiva) was used with Ni 2 + Method for fixing His-tagged EphA2 protein.

[0143] In the experiment, 5 mM NiCl2 (Sigma, catalog number: 339350) was injected at a flow rate of 30 μL / min for 120 seconds to capture Ni. 2 + ions were then injected into the sensor surface, followed by injection of EphA2 protein diluted to 10 μg / mL (injection time 70 seconds) to immobilize the target protein. The analysis buffer was PBS (10X, US EVERBRIGHT, catalog number: DZ8034L).

[0144] The highest concentration of the EphA2 radioactive probe precursor was 1000 nM, and multiple concentration gradients were established using a 2-fold serial dilution. The injection flow rate was 30 μL / min, the binding time was 120 seconds, and the dissociation time was 480 seconds. After each round of analysis, surface regeneration was performed sequentially using 0.5 M EDTA (Beyotime, catalog number: C0196) and 0.1 M NaOH (Titan, catalog number: G19852A). Data analysis was performed using BIAcore T200 Evaluation Software, and a 1:1 Langmuir binding model was used for fitting to calculate the binding rate constant (ka), dissociation rate constant (kd), and apparent dissociation constant (KD).

[0145] SPR experiments showed that all EphA2-targeting probes specifically bound to the immobilized EphA2 protein, and the sensing spectra exhibited concentration-dependent response curves with good goodness of fit. 2 Value < 0.7.

[0146] See results Figure 7 As shown, the specific dynamic parameters are as follows: DOTA-FZ-BT508-1: KD=185.7nM; see Figure 8 As shown, the specific kinetic parameters are as follows: NOTA-FZ-BT508-2: KD = 43.09 nM; see Figure 9 As shown, the specific dynamic parameters are as follows: NOTA-FZ-BT508-1: KD=64.40nM.

[0147] Example 4: Compound 68 Ga-DOTA-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68 Study on the separation coefficient of Ga-DOTA-FZ-BT508-3

[0148] Log P: Approximately 37 kBq of purified Ga-68-labeled radioactive probe was mixed with 2 mL of a 1:1 (v / v) ultrapure water / n-octanol mixture. After mixing (vortexing for 5 min), the aqueous and organic phases were separated by centrifugation (15,000 × g, 5 min). 100 μL of sample was taken from each phase, and its radioactivity was measured using a gamma counter (n = 5).

[0149] Log D 7.4 Using the same method, approximately 37 kBq of Ga-68-labeled radioactive probe was mixed with 2 mL of a 1:1 (volume ratio) phosphate-buffered saline (PBS, pH 7.4) / n-octanol mixture. The experiment was repeated with n=5.

[0150] See results Figure 10 As shown, 68 Ga-DOTA-FZ-BT508-1 (Log P: -3.1±0.42; Log D 7.4 (-2.9±0.38); see Figure 11 As shown, 68 Ga-NOTA-FZ-BT508-2 (Log P: -2.4±0.19; Log D 7.4 (-2.4±0.24); see Figure 12 As shown, 68 Ga-DOTA-FZ-BT508-3 (Log P: -2.3±0.19; Log D 7.4 (-2.4±0.36).

[0151] Compound in Example 5 68 Ga-DOTA-FZ-BT508-1 68Ga-NOTA-FZ-BT508-2 68 Stability Study of Ga-DOTA-FZ-BT508-3

[0152] (1) Stability of physiological saline

[0153] (1) Take 3 EP tubes and add 200 μL (0.74-2.96 MBq) of purified Ga-68 labeled radioactive probe (i.e., 68 Ga-FZ-BT508-1 / 2 / 3);

[0154] (2) Add 800 μL of physiological saline to each of the above 3 EP tubes and shake well.

[0155] (3) Incubate the mixture at room temperature for 0, 1, 2 and 3 hours respectively;

[0156] (4) Then, 100 μL of the above mixture was taken from each EP tube and analyzed by radio-HPLC to evaluate the stability of the radioactive probe in physiological saline.

[0157] (5) Data were analyzed using the software GraphPad Prism 9.0 to analyze the stability data of physiological saline.

[0158] See the results Figure 13 As shown, 3 hours later 68 The radiochemical purity of Ga-DOTA-FZ-BT508-1 remains greater than 95%; see Figure 14 As shown, 3 hours later 68 The radiochemical purity of Ga-NOTA-FZ-BT508-2 remains greater than 95%. Figure 15 As shown, 3 hours later 68 The radiochemical purity of Ga-DOTA-FZ-BT508-3 remains greater than 95%, and all three probes maintain good stability.

[0159] (2) Human serum stability

[0160] (1) Take 3 EP tubes and add 200 μL (0.74-2.96 MBq) of purified Ga-68 labeled radioactive probe (i.e., 68 Ga-FZ-BT508-1 / 2 / 3);

[0161] (2) Add 800 μL of human serum to each of the above 3 EP tubes and shake well.

[0162] (3) Incubate the mixture at room temperature for 0, 1, 2 and 3 hours respectively;

[0163] (4) Then, 100 μL of the above mixture was taken from each EP tube and analyzed by radio-HPLC to evaluate the stability of the radioactive probe in human serum;

[0164] (5) Data were analyzed using the software GraphPad Prism 9.0 to analyze the stability data of physiological saline.

[0165] See results Figure 16 As shown, 3 hours later 68 The radiochemical purity of Ga-DOTA-FZ-BT508-1 remains greater than 95%; see Figure 17 As shown, 3 hours later 68 The radiochemical purity of Ga-NOTA-FZ-BT508-2 remains greater than 95%. Figure 18 As shown, 3 hours later 68 The radiochemical purity of Ga-DOTA-FZ-BT508-3 remains greater than 95%, and all three probes maintain good stability.

[0166] Example 6: Compound 68 Ga-DOTA-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68 PET Imaging Study of Ga-DOTA-FZ-BT508-3

[0167] SPF-grade female Balb / c nude mice, provided by Shanghai Jicui Biotechnology Co., Ltd., were injected subcutaneously with HT-1080 human renal cell carcinoma cells via the right axilla after two days of acclimatization in the animal facility. The injection volume was 0.1 mL (1×10⁻⁶). 8 Cells / mL dispersed in PBS), and after injection, the patient was fed for 4-6 weeks until the solid tumor reached 5-11 mm in size for imaging experiments. 3.7-7.4 MBq / 0.2 mL was injected via the tail vein. 68 Ga-FZ-BT508-1 / 2 / 3 was injected, and small animal PET imaging experiments were performed at 0.5, 1, and 2 hours post-injection. The images are shown below. Figure 6 .

[0168] Animal experiment results are shown in Figure 19 , 20 As shown in Figure 21, the uptake of major organs such as tumors is illustrated. 68 Ga-DOTA-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68Ga-DOTA-FZ-BT508-3 exhibited high tumor uptake in the HT-1080 model, with clear distinction between tumor and non-tumor regions. All three probes (i.e., the PET imaging agents described in this invention) are primarily excreted via the kidneys and bladder, avoiding diagnostic interference with monitoring tumor metastasis in vital abdominal organs such as the liver, spleen, and stomach. This provides a new technical approach for efficient monitoring and imaging of EphA2 expression in tumors.

[0169] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A PET imaging agent targeting the EphA2 receptor, characterized in that, Its structure is shown in equation X below: Wherein, R1 is selected from any one or more of the following groups 1, 2, and 3: Or a pharmaceutically acceptable salt thereof, where n is an integer selected from 1 to 12.

2. The PET imaging agent targeting the EphA2 receptor according to claim 1, characterized in that, The PET imaging agent targeting the EphA2 receptor has the structure shown in Formula I, II, or III below: Or a pharmaceutically acceptable salt thereof, wherein in formulas I to III, n is an integer selected from 1 to 12.

3. A PET imaging agent precursor targeting the EphA2 receptor, characterized in that, Its structure is shown in equation XI below: Wherein, R2 is selected from any one or more of the following groups 4, 5, and 6: Or a pharmaceutically acceptable salt thereof, where n is an integer selected from 1 to 12.

4. The PET imaging agent precursor targeting the EphA2 receptor according to claim 3, characterized in that, The PET developer precursor described herein has the structure shown in formula IV, V or VI below: Or its pharmaceutically acceptable salt.

5. A method for preparing the EphA2 receptor-targeted PET imaging agent precursor as described in claim 3 or 4, characterized in that, Includes the following steps: Compound G was dissolved in a trifluoroacetic acid (TFA) solution, and the mixture was stirred at room temperature until the reaction was complete. Then, ether was added for washing, and the mixture was vacuum filtered to obtain the PET developer precursor. The structure of compound G is shown in formula XII below: Wherein, R3 is selected from any one or more of the following groups 7, 8, and 9: Furthermore, the structure of compound G is shown in formula VII, VIII, or IX:

6. The method for preparing the EphA2 receptor-targeted PET imaging agent precursor according to claim 5, characterized in that, The concentration of the TFA is 80–100 v / v%; more preferably, the concentration of the TFA is 90 v / v%.

7. The method for preparing the EphA2 receptor-targeted PET imaging agent precursor according to claim 5, characterized in that, The preparation method of compound G includes the following steps: S1: Sequentially add compound Boc-(SAR) 10- Ala-COOH or the compound Boc-(PEG) 8- Ala-COOH), 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, and N,N-diisopropylethylamine were dissolved in anhydrous DMF. After stirring at room temperature, the bicyclic peptide was added, and the mixture was stirred at room temperature until the reaction was complete. A saturated NaHCO3 solution was added, and the mixture was extracted with ethyl acetate. The organic phases were combined and then dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain compound A, which was a solid powder. Further, the molar ratio of Boc-(SAR)10-Ala-COOH or Boc-(PEG)8-Ala-COOH:2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate:N,N-diisopropylethylamine:bicyclic peptide was 1.2-2:1.2-2:2.5-3:

1. Even further, Boc-(SAR) 10- Ala-COOH or Boc-(PEG) 8- The molar ratio of Ala-COOH: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine: bicyclic peptide is 1.3:1.3:2.6:1; Furthermore, the bicyclic peptide structure is shown below: S2: Add compound A to a TFA-dichloromethane solution with a volume percentage of 40-60%, stir at room temperature until the reaction is complete, concentrate under reduced pressure, wash with diethyl ether, and filter under vacuum to obtain compound B; S3: Compound B was dissolved in anhydrous DMF with compounds Boc-3-(2-naphthyl)-L-alanine, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, and N,N-diisopropylethylamine. The mixture was stirred at room temperature until the reaction was complete. A saturated NaHCO3 solution was then added, followed by extraction with ethyl acetate. The organic phases were combined and successively dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure. The crude product was purified to obtain compound C, which was a solid powder. Further, the compound... Compound B: The molar ratio of Boc-3-(2-naphthalene)-L-alanine: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.2-2:1.2-2:2.5-3; furthermore, the molar ratio of compound B: Boc-3-(2-naphthalene)-L-alanine: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.3:1.3:2.6; S4: Add compound C to a TFA-dichloromethane solution with a volume percentage of 40-60%, stir at room temperature until the reaction is complete, concentrate under reduced pressure, wash with diethyl ether, and filter under vacuum to obtain compound D; S5: Compound D, compound BOC-tranexamic acid, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, and N,N-diisopropylethylamine were dissolved in anhydrous DMF and reacted with stirring at room temperature until the reaction was complete. Then, saturated NaHCO3 solution was added, and the mixture was extracted with ethyl acetate. The organic phases were combined and successively dried over anhydrous Na2SO4, filtered, and concentrated under reduced pressure to obtain compound E as a solid powder. In the first step, the molar ratio of compound D: BOC-tranexamic acid: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.2-3:1.2-2:2.5-3; further, the molar ratio of compound D: BOC-tranexamic acid: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.3:1.3:2.6; S6: Add compound E to a TFA-dichloromethane solution with a volume percentage of 40-60%, stir at room temperature until the reaction is complete, concentrate under reduced pressure, wash with diethyl ether, and filter under vacuum to obtain compound F; S7: Compound F, compound DOTA-(COOt-Bu)3 or compound Nota-(COOt-Bu)2, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate and N,N-diisopropylethylamine were dissolved in anhydrous DMF and stirred at room temperature until the reaction was complete. A saturated NaHCO3 solution was added, and the mixture was extracted with ethyl acetate. The organic phases were combined and dried sequentially through anhydrous Na2SO4. After filtration and concentration under reduced pressure, a crude product was obtained. The crude product was purified to give compound G, which was a solid powder. Further, compound F: compound DOT The molar ratio of A-(COOt-Bu)3 or NOTA-(COOt-Bu)2: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.2~2:1.2~2:2.5~3; furthermore, the molar ratio of compound F: compound DOTA-(COOt-Bu)3 or NOTA-(COOt-Bu)2: 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate: N,N-diisopropylethylamine is 1:1.3:1.3:2.

6.

8. A PET imaging probe targeting the EphA2 receptor, characterized in that, Obtained by radioactive element labeling using the PET developer according to any one of claims 1 or 2; further, the radioactive element is... 68 Ga.

9. A method for preparing a PET imaging agent probe targeting the EphA2 receptor as described in claim 8, characterized in that, Includes the following steps: Will 68 The GaCl3 eluent was mixed with the PET developer solution and reacted at 90-100℃ for 8-12 min. After cooling to room temperature, the mixture was diluted with water and separated using a C-18 column. The eluent was eluted with a 60-80 v / v% ethanol aqueous solution and concentrated to dryness to obtain the PET developer probe solution targeting the EphA2 receptor. Furthermore, the aforementioned 68 The preparation method of GaCl3 rinsing solution includes the following steps: injecting 0.1M hydrochloric acid solution into a germanium-gallium generator for rinsing to obtain... 68 The reaction solution was rinsed with GaCl3, and then sodium acetate solution was added to adjust the pH of the system to 4.0-4.

2. Furthermore, the PET developer solution is 68 Ga-DOTA-FZ-BT508-1 68 Ga-NOTA-FZ-BT508-2 68 Ga-DOTA-FZ-BT508-3 solution.

10. The use of a PET imaging agent targeting the EphA2 receptor as described in any one of claims 1 to 2 or a PET imaging agent probe targeting the EphA2 receptor as described in any one of claims 8 to 9 in the preparation of a detection reagent for EphA2 protein-related diseases or conditions; Furthermore, the diseases or conditions associated with the EphA2 protein include tumors or inflammation; Furthermore, the tumors include fibrosarcoma, breast cancer, pancreatic cancer, and prostate cancer.

11. A pharmaceutical composition, characterized in that, Includes the PET imaging agent targeting the EphA2 receptor as described in any one of claims 1 to 2, or the PET imaging agent probe targeting the EphA2 receptor as described in any one of claims 8 to 9, and its pharmaceutically acceptable carrier.

12. A reagent kit, characterized in that, Includes the PET imaging agent targeting the EphA2 receptor as described in any one of claims 1 to 2, or the PET imaging agent probe targeting the EphA2 receptor as described in any one of claims 8 to 9.

Images