Linkers, compounds, nuclide conjugates targeting prostate-specific membrane antigen and uses thereof

Abstract

The present application relates to the technical field of nuclear medicine, and particularly relates to a linker, a compound, a radionuclide conjugate targeting prostate specific membrane antigen (PSMA) and application thereof. The linker with a specific structure is connected with a targeting carrier and a targeting ligand respectively to form a compound targeting prostate specific membrane antigen, and the compound is further labeled with a radionuclide to prepare a radionuclide conjugate. The linker in the present application can effectively improve the affinity of the PSMA ligand, and the compound including the linker can be used as a bifunctional chelating agent to simultaneously realize labeling of a diagnostic radionuclide and a therapeutic radionuclide, and realize diagnosis and treatment integration. In addition, the radionuclide conjugate constructed from the linker has good metabolic property, and the structural stability is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of nuclear medicine technology, and in particular to a linker, compound, radionuclide conjugate targeting prostate-specific membrane antigens and their applications. Background Technology

[0002] Prostate-specific membrane antigen (PSMA) is highly expressed on the membranes of most prostate cancer cells. Its extracellular domain can specifically bind to antibodies or small-molecule radioligands, making it a highly promising target for the diagnosis and treatment of prostate cancer. In radiopharmaceutical development, the PSMA-targeting linker, as a key structural unit connecting the PSMA-targeting ligand to the therapeutic or diagnostic payload, must not only maintain the ligand's high affinity and targeting specificity for PSMA, but also ensure efficient delivery of the payload to tumor tissue and controlled release at the target site. Therefore, the design of the linker directly determines the biological activity, pharmacokinetic behavior, in vivo stability, and ultimate therapeutic effect of the radiopharmaceutical.

[0003] Current research reports that introducing highly negatively charged linker structures can significantly reduce the uptake of PSMA-targeting tracers in non-target tissues such as salivary glands, thereby alleviating adverse reactions such as dry mouth caused by radiotherapy. Furthermore, some linkers are designed to cleave in response to specific conditions in the tumor microenvironment (such as low pH, high expression of specific enzymes, or a reducing environment) to achieve targeted drug release; there are also strategies that indirectly release active ingredients through the metabolic degradation of drug conjugates within cells.

[0004] However, existing linker structures still have limitations. The constructed radionuclide conjugates generally exhibit problems such as low tumor-targeted uptake efficiency and insufficient in vivo stability, which limits their potential for application in clinical diagnosis and treatment. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a linker, compound, radionuclide conjugate, and their applications targeting prostate-specific membrane antigens. This invention employs a series of novel linkers targeting prostate-specific membrane antigens, which are hydrophilic and / or rigid. The radionuclide conjugates prepared by further processing compounds formed by linking a targeting carrier and a targeting ligand using these linkers exhibit advantages such as high tumor uptake and high stability.

[0006] The inventors discovered that, on the one hand, rigid linkers can restrict the conformation of the PSMA binding unit when it binds to the PSMA target, helping to maintain the optimal binding posture and improve the binding affinity to PSMA. This conformational restriction helps reduce the loss of conformational entropy, thereby enhancing binding stability. On the other hand, rigid linkers with a well-defined three-dimensional structure may reduce non-specific interactions with non-target proteins or biomolecules, helping to reduce background signals and off-target accumulation. Furthermore, rigid linkers can also regulate their metabolism and excretion in the liver and kidneys through molecular shape, thereby optimizing pharmacokinetic properties.

[0007] Meanwhile, the inventors' research also found that hydrophilic linkers can significantly improve the water solubility of the entire molecule. In particular, for intravenously injected radiopharmaceuticals, hydrophilic polymers such as polyethylene glycol (PEG) chains can form a hydration layer, reducing the non-specific binding of the drug to plasma proteins and prolonging the circulation time of the drug in the blood. A longer circulation time helps the drug reach the tumor site better and improve the tumor uptake rate.

[0008] The objective of this invention is achieved through the following technical solution: In a first aspect of the present invention, a compound targeting prostate-specific membrane antigen is provided, the compound having the structure of: a targeting carrier-linker-targeting ligand; The connector can have any of the structures shown in Equations 01 to 20: , , , , , , , , , , , , , , , , , , , ; Where n takes values ​​from 0 to 3. This is the connection site.

[0009] Specifically, n can take the values ​​0, 1, 2, or 3. This refers to the connection site between the target vector and the linker.

[0010] In some embodiments, the targeting carrier has a structure as shown in Formula I: Equation I, where Equation I contains This is the connection site.

[0011] The aforementioned targeting vectors possess high specificity and multifunctionality. Since PSMA is primarily overexpressed on the surface of cancer cells but expressed at very low levels in normal tissues, PSMA vectors require high specificity to effectively distinguish between cancer cells and normal cells. Furthermore, the PSMA targeting vectors in these embodiments can be used for both diagnostic and therapeutic purposes. For example, in diagnostics, the PSMA-targeted radioisotope can be used for positron emission tomography (PET) imaging; in therapeutics, it can be conjugated with therapeutic radiopharmaceuticals or chemotherapeutic drugs to achieve targeted therapy.

[0012] In some embodiments, the compound has a structure as shown in formulas i to xx: Formula i, Formula ii Equation iii Formula iv Formula v Formula vi Form vii, Formula viii Formula ix Formula x Formula xi Formula xii, Formula xiii, XIV, Formula xv, Formula xvi Formula xvii, Formulas xviii, formula xix, Formula xx; Where R is the targeting ligand; n takes values ​​from 0 to 2. More specifically, n can take values ​​of 0, 1, or 2.

[0013] Specifically, in formula i, the carboxyl and amino residues on lysine are used to connect the targeting ligand and the chelating ligand, respectively. Since lysine is a natural amino acid, it can improve biocompatibility. At the same time, the amino group of lysine is protected by the Fmoc protecting group, introducing a sterically hindered group, which is beneficial to unfolding the entire RDC molecule, reducing the possibility of molecule folding, and improving the stability and targeting selectivity of radionuclide labeling.

[0014] Specifically, in formula ii, using a PEG chain as a linker is expected to increase the overall water solubility of the molecule and improve the drug metabolism rate. At the same time, phenylalanine is introduced near the chelating ligand and the targeting ligand, and the phenyl residues on phenylalanine are used to restrict the overall degree of freedom of the molecule and reduce coiling and promote the elongation conformation of the linker.

[0015] Specifically, in formula vi, the linker is composed of three glutamic acid residues. On the one hand, the carboxyl residues on the glutamic acid provide hydrophilicity and improve the hydrophilic properties of the molecule. On the other hand, the electrostatic interaction between the carboxyl groups prevents the entire molecule from aggregating and increases the target binding affinity.

[0016] Specifically, in formula vii, two cyclohexanes are introduced into the linker pathway to increase chain rigidity and reduce molecular folding. Phenylalanine is introduced near the chelating ligand and the targeting ligand, and the phenyl residues on the phenylalanine are used to restrict the entire molecular degree of freedom, reduce coiling, and promote the elongation conformation of the linker.

[0017] Specifically, in formula viii, two natural tyrosine residues are introduced, and phenolic residues of tyrosine residues are used to increase the steric hindrance of the molecule.

[0018] Specifically, in formula ix, the click reaction between the thiol residue of leucine and maleimide olefin is utilized, which is beneficial for rapid and efficient synthesis. At the same time, maleimide has a certain rigid structure, which can reduce the degree of molecular folding.

[0019] Specifically, in formula x, the linkers are all composed of ring structures, which further improves the rigidity of the linkers. In order to reduce the strong hydrophobicity brought by cyclohexane and benzene ring, sulfonic acid groups are introduced on the benzene ring to increase the hydrophilicity of the linkers and improve the drug's in vivo metabolism rate.

[0020] Specifically, in formula xi, the introduction of PEG significantly improves water solubility, reduces non-specific binding to plasma proteins, prolongs the half-life in blood circulation, increases AUC, reduces clearance rate, and also reduces the risk of being recognized and cleared by the immune system. Simultaneously, the long-chain PEG provides a certain degree of rigidity and protects adjacent groups from enzymatic degradation. The piperazine ring enhances the rigidity of the system and makes metabolism more stable.

[0021] Specifically, in formula xii, the sulfonic acid group provides strong hydrophilicity and negative charge, the trans olefin provides rigidity, and the high-strain ring of cyclopropane significantly restricts the conformation, which is beneficial to maintaining the active conformation. Furthermore, the trans olefin and cyclopropane are relatively stable and have metabolic stability.

[0022] Specifically, in formula xiii, a bispyridine structure is introduced to provide a rigid plane. A short PEG or alkyl chain is inserted in the middle to provide a certain length and flexible connection, which makes it have good water solubility. The rigid structure is conducive to maintaining the molecular shape. Pyridine N can act as a hydrogen bond acceptor to participate in target interactions. The structure is relatively simple.

[0023] Specifically, in formula xiv, both morpholine and tetrazolium have strong hydrophilicity and rigidity, which can maintain conformation and reduce protein binding. As a stable carboxylic acid bioisostere, tetrazolium has good metabolic stability.

[0024] Specifically, in formula xv, the triazole ring serves as the core, providing extremely strong overall rigidity and metabolic stability, reducing the attack sites and rates of metabolic enzymes. The PEG chain provides connection length and a certain degree of flexibility. The rigid linker can reduce the situation where the linker itself folds and blocks the pharmacophore (or targeting ligand).

[0025] Specifically, in formula xvi, phenol readily binds to serum proteins, prolonging its half-life. Phenol itself has a certain rigidity and water solubility, which can improve the bioavailability of lipid-soluble molecules. At the same time, PEG is introduced to protect adjacent groups from enzyme degradation.

[0026] In some embodiments, the targeting ligand is selected from any of the following structures: 3P-C-NETA, DOTA, NOTA, HYNIC, TPA, DTPA, NODAGA, TETA, PCTA, DOTAM.

[0027] The structure of the target ligand portion is as follows: , , , , .

[0028] Specifically, the nuclides that DOTA can chelate include: 52 Mn, 55 Co、 64 Cu、 66 Ga、 86 Y、 89 Zr、 152 Tb, 68 Ga、 111 In、 177 Lu et al., with their macrocyclic structure, make them highly stable and easily modified chelating agents. They can form complexes with a variety of metal ions; they are easily modified to target different disease states. They are ideal macrocyclic chelating agents for lanthanides, but can also be used for other metals, primarily transition metals. DOTA can chelate... 64 Cu and 68 Ga is used in PET scans and can also be chelated.111 In and 90 Y is used in SPECT and radiotherapy, and can be combined with the paramagnetic lanthanide metal ion gadolinium for MRI.

[0029] Specifically, the nuclides that DOTA can chelate include: 18 F, 55 Co、 64 Cu、 66 Ga、 68 Ga,NOTA, as a chelating agent, can form stable complexes with metal ions, thereby reducing the interference of metal ions on biomolecules. It consists of four nitrogen atoms forming a six-membered ring structure, which can form stable five-membered ring complexes with metal ions. The advantages of NOTA lie in its strong affinity for metal ions, the stability of the resulting complexes, and its non-toxicity to biomolecules. It is a bifunctional chelate that can be used in PET imaging and can also be used for probe design and signal amplification through multivalent effects.

[0030] In some implementations, the targeting ligand is 3P-C-NETA.

[0031] The 3P-C-NETA structure is as follows: ; Among them, 3p-C-NETA is a multifunctional chelating agent that can be used for both diagnostic applications (AI) and other purposes. 18 F) can also be used for targeted radionuclide therapy. 213 Bi、 177 Lu、 161 Tb has the potential to become a new first-line therapeutic chelating agent in clinical applications of nuclear medicine.

[0032] In some embodiments, the structure of the compound is shown below: , , , , , , , , , .

[0033] In a second aspect of the invention, a radionuclide conjugate targeting a prostate-specific membrane antigen is provided, the radionuclide conjugate comprising the aforementioned compound and a radionuclide.

[0034] In some embodiments, the radionuclide is selected from... 18 F, 99m Tc,68 Ga、 64 Cu、 111 In、 90 Y、 225 Ac、 137 Cs、 90 Sr、 125 I, 131 I, 153 Sm and 177 At least one of the Lu nuclides.

[0035] In some embodiments, the radionuclide is selected from... 18 F and / or 177 Lu.

[0036] It is understandable that only a portion of the radionuclides are shown above. In practical applications, they can be coupled for SPECT imaging. 99 Tc, 131 I, 133 Xe, 67 Ga、 111 In、 123 I, 201 TL, used for PET imaging 18 F, 68 Ga、 64 Cu, used in radioimmunoassay 125 I, used for radiotherapy 131 I, 32 P, 90 Y、 169 Er、 153 Sm、 166 Ho、 177 Lu、 188 Re、 223 Ra、 225 Ac、 227 Th、 211 At.

[0037] In a third aspect of the invention, a method for preparing a radionuclide conjugate targeting a prostate-specific membrane antigen as described above is provided, comprising the following steps: adding the aforementioned compound and a salt solution containing a radionuclide to a solution containing a NaAc buffer system, and heating the solution to react, thereby obtaining the radionuclide conjugate.

[0038] In a fourth aspect of the invention, the use of the aforementioned composition or the aforementioned radionuclide conjugate in the preparation of pharmaceutical salts, prodrugs or esters, pharmaceutical carriers, and pharmaceutical compositions is provided.

[0039] In some embodiments, the composition or radionuclide conjugate is applied in the form of an injectable formulation.

[0040] In a fifth aspect of the invention, the use of the aforementioned composition or the aforementioned radionuclide conjugate in the preparation of imaging diagnostic reagents is provided.

[0041] In some embodiments, the imaging diagnostic product is used to diagnose prostate cancer or its metastases.

[0042] In a sixth aspect of the invention, there is provided the use of the composition according to the foregoing or the radionuclide conjugate according to the foregoing in the preparation of a medicament for treating prostate cancer or its metastases.

[0043] Compared with the prior art, the present invention has the following beneficial effects: 1) Through the rational optimization design of the linker structure, the present invention prepares a radionuclide conjugate that improves the binding affinity between the PSMA ligand and the target, while also significantly improving the drug uptake and retention time in tumor tissues, and exhibiting high stability.

[0044] 2) The radionuclide conjugates prepared by this invention can be used for imaging diagnosis and radiotherapy of prostate cancer patients, enabling diagnosis, medication guidance and treatment of prostate cancer patients.

[0045] 3) The compound specifically designed in this invention to target prostate-specific membrane antigens uses 3P-C-NETA as a bifunctional chelating agent, enabling both labeling and... 18 F can also be marked 177 Lu, the corresponding prepared radionuclide conjugates can achieve the effect of integrated diagnosis and treatment. Attached Figure Description

[0046] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 To verify the example in Example 1 18 Stability analysis of F-LSFZ-04 in PBS and FBS; Figure 2 To verify the example in Example 1 177 Stability analysis of Lu-LSFZ-05 in PBS and FBS; Figure 3 To verify the uptake results of various radionuclide-labeled conjugates by LNCaP cells in Example 2; wherein, Figure 3 A is 18 F-LSFZ-04 18 Results of F-LSFZ-05 intake; Figure 3 B is 177 Lu-LSFZ-04 177 Lu-LSFZ-05 177Results of Lu-PSMA-617 intake; Figure 4 To verify the cell-competitive binding results of the PSMA-targeting compound in LNCaP cells in Example 3; Figure 5 To verify the example in Example 4 18 Pharmacokinetic diagram of F-LSFZ-04 in normal mice; Figure 6 To verify the example in Example 4 18 Pharmacokinetic diagram of F-LSFZ-05 in normal mice; Figure 7 To verify the example in Example 4 18 Biodistribution results of F-LSFZ-04 in normal mice; Figure 8 To verify the example in Example 4 18 Biodistribution results of F-LSFZ-05 in normal mice; Figure 9 To verify the example in Example 4 18 F-LSFZ-04 lipid-water partition coefficient diagram; Figure 10 To verify the example in Example 4 18 F-LSFZ-05 lipid-water partition coefficient diagram; Figure 11 To verify the example in Example 5 18 F-LSFZ-04 and 18 Micro PET / CT results of F-LSFZ-05 in LNCaP tumor model mice; among which, Figure 11 A is a PET / CT image; Figure 11 B is 18 F-LSFZ-04 18 Tissue uptake of F-LSFZ-05 at different time points (1h / 2h / 4h) and in the blocking group; Figure 11 C is 18 F-LSFZ-04 18 F-LSFZ-05 uptake ratio of target tissue / non-target tissue at different time points; Figure 12 To verify the results in Example 6 18 Biodistribution of F-LSFZ-04 in LNCaP tumor-bearing mice; Figure 13 To verify the results in Example 6 18 Biodistribution of F-LSFZ-05 in LNCaP tumor-bearing mice; Figure 14 To verify the example in Example 7 177SPECT image of Lu-LSFZ-04 in LNCaP tumor model mice; Figure 15 To verify the example in Example 7 177 SPECT image of Lu-LSFZ-05 in LNCaP tumor model mice; Figure 16 To verify the changes in tumor volume (left figure) and mouse weight (right figure) in each experimental group of mice in Example 8; Figure 17 Gross images of LNCaP subcutaneous tumors in mice of each experimental group in Example 8 were taken to verify their presence. Figure 18 To verify the staining results of the heart, liver, spleen, lungs, and kidneys of the mice in the three experimental groups in Example 8; Figure 19 To verify the results of blood routine, liver function, and kidney function biochemical index tests on the blood of the three experimental groups of mice in Example 8. Detailed Implementation

[0047] Terminology Explanation In the context of this invention, "prostate-specific membrane antigen (PSMA)" is a transmembrane protein expressed in various cancers, especially highly expressed in prostate cancer cells, and is an important target for the diagnosis and treatment of prostate cancer.

[0048] In the context of this invention, the "linker" is a key component connecting the PSMA-targeting molecule to the therapeutic or diagnostic payload. Its main function is to deliver the payload to the target cancer cells while maintaining PSMA specific binding, and to ensure effective drug release at the target site. It should be noted that, in the context of this invention, modifications to the linker based on its improvement principles can be extended to peptide linkers, lipid or albumin-binding linkers, cleavable linkers, and non-cleavable linkers. All strategies for modification based on the principles of this invention are included within the scope of protection of this invention.

[0049] In the context of this invention, "targeting carrier" and "targeting ligand" are two key components of targeted drug delivery. In this context, a targeting ligand refers to a molecule that can specifically recognize and bind to specific molecules (such as receptors, antigens, or enzymes) on the surface or inside the target cell. A molecule that can specifically bind to PSMA is a PSMA targeting ligand. Targeting ligands bind to target molecules with high affinity and high selectivity through intermolecular forces. PSMA targeting ligands typically include specific chemical groups, such as urea derivatives, which can form stable interactions with key amino acid residues in the active site of the PSMA protein.

[0050] In the context of this invention, "targeting carrier" refers to a carrier system used to encapsulate, carry, or conjugate drugs and deliver them to a specific target via a targeting ligand. The targeting carrier can be nanoparticles, liposomes, micelles, polymer conjugates, etc. The targeting ligand is usually conjugated to the surface of the targeting carrier, enabling the carrier to specifically bind to the target molecule via the ligand. For example, in the development of PSMA-targeting radioligands, a molecular structure containing a PSMA targeting unit, a linker, and a chelating agent can be designed. The PSMA targeting unit is the targeting ligand, and the entire molecule (including the linker and chelating agent) can be regarded as a small targeting carrier to deliver the radionuclide to PSMA-expressing tumor cells.

[0051] Example 1 This embodiment provides a method for preparing a compound (LSFZ-01) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-01 was synthesized.

[0052] The LSFZ-01 was characterized by NMR, and the results are as follows: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.18 (s, 1H),7.85 – 7.79 (m, 2H), 7.62 (dd, J = 7.6, 1.4 Hz, 2H), 7.50 (td, J = 7.7, 1.2 Hz, 2H), 7.44 (dd, J = 8.0, 1.4 Hz, 3H), 7.40 (dd, J = 7.8, 1.5 Hz, 1H), 7.11 (dt, J =7.9, 1.1 Hz, 2H), 6.86 (t, J = 4.9 Hz, 1H), 6.58 (t, J = 4.9 Hz, 1H), 6.03 (d, J =8.6 Hz, 1H), 5.44 – 5.39 (m, 1H), 4.66 (dtd, J = 14.4, 8.5, 5.9 Hz, 1H), 4.49 –4.40 (m, 3H), 4.03 (dt, J = 8.8, 5.9 Hz, 1H), 3.41 (d, J= 1.6 Hz, 4H), 3.18 –3.04 (m, 4H), 2.93 – 2.84 (m, 2H), 2.82 – 2.73 (m, 3H), 2.73 – 2.58 (m, 15H), 2.58 – 2.33 (m, 18H), 2.02 – 1.91 (m, 2H), 1.70 – 1.28 (m, 14H).

[0053] Example 2 This embodiment provides a method for preparing a compound (LSFZ-02) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-02 was synthesized.

[0054] The LSFZ-02 was characterized by NMR, and the results are as follows: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.18 (s, 1H), 8.07 (d, J = 9.5 Hz, 1H), 7.77 (t, J = 4.9 Hz, 1H), 7.47 – 7.41 (m, 2H), 7.30 –7.26 (m, 2H), 7.26 – 7.18 (m, 8H), 7.11 (dt, J = 7.9, 1.1 Hz, 2H), 4.58 (ddt, J =40.8, 9.3, 7.3 Hz, 2H), 4.31 (td, J = 5.0, 2.1 Hz, 4H), 3.59 (t, J = 5.1 Hz, 4H), 3.41 (d, J = 1.6 Hz, 4H), 3.15 (qd, J = 5.2, 2.9 Hz, 2H), 3.08 (s, 2H), 3.00 (dt, J= 7.5, 0.8 Hz, 4H), 2.93 – 2.84 (m, 2H), 2.82 – 2.71 (m, 3H), 2.71 – 2.57(m, 16H), 2.57 – 2.54 (m, 3H), 2.54 – 2.45 (m, 8H), 2.45 – 2.40 (m, 3H), 2.40 – 2.33 (m, 3H), 2.03 – 1.91 (m, 2H), 1.70 – 1.28 (m, 10H).

[0055] Example 3 This embodiment provides a method for preparing a compound (LSFZ-03) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-03 was synthesized.

[0056] The LSFZ-03 was characterized by NMR, and the results are as follows: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.18 (s, 1H), 8.07 (d, J = 9.5 Hz, 1H), 7.77 (t, J = 4.9 Hz, 1H), 7.63 (d, J = 9.3 Hz, 1H), 7.48– 7.38 (m, 2H), 7.30 – 7.18 (m, 10H), 7.11 (dt, J = 7.9, 1.1 Hz, 2H), 4.57(ddt, J = 37.4, 9.3, 7.4 Hz, 2H), 4.09 (td, J = 6.5, 0.9 Hz, 4H), 3.41 (d, J = 1.6Hz, 4H), 3.15 (qd, J = 5.2, 2.9 Hz, 2H), 3.00 (dt, J = 7.6, 0.8 Hz, 4H), 2.82 –2.33 (m, 35H), 1.76 – 1.28 (m, 16H).

[0057] Example 4 This embodiment provides a method for preparing a compound (LSFZ-04) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-04 was synthesized.

[0058] NMR characterization of LSFZ-04 yielded the following results: ¹H NMR (DMSO-d6, 300 MHz) δ: 13.03, 12.66, 12.27, 12.01 (each br s, 1H, -COOH-OH), 9.97 (br s, 1H, -CONH-), 8.32 (br s, 1H, -NH-), 8.01 (br s, 1H, -NH-), 7.96 (m, 1H, Ar-H), 7.93 (m, 1H, Ar-H), 7.84 (m, 1H, Ar-H), 7.62 (m, 1H, Ar-H), 7.54 (m, 1H, Ar-H), 7.51 (m, 1H,Ar-H), 7.48 (m, 1H, Ar-H), 7.45 (m, 2H, Ar-H), 7.14 (m, 2H, Ar-H), 6.46 (brs, 1H, -NH-), 4.55 (m, 2H, -CH-), 4.52 (m, 1H, -CH-), 3.42 (m, 1H, -CH2-), 3.30 (m, 2H, -CH2-), 3.18 (m, 1H, -CH2-), 2.63 (m, 2H, -CH2-), 2.46 (t, J =7.1 Hz, 6H, -CH2-), 2.45 (m, 2H, -CH2-), 2.43 (m, 1H, -CH-), 2.33 (m, 3H, -CH2-), 2.25 (m, 1H, -CH2-), 2.10 (m, 1H, -CH2-), 1.76 (m, 1H, -CH2-), 1.53 (m,1H, -CH2-), 1.31 (m, 1H, -CH2-).

[0059] Example 5 This embodiment provides a method for preparing a compound (LSFZ-05) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-05 was synthesized.

[0060] NMR characterization of LSFZ-05 was performed, and the results are as follows: ¹H NMR (DMSO-d6, 300 MHz, calculated) δ: 13.03, 12.66, 12.27, 12.01 (each br s, 1H, -COOH-OH), 9.97 (br s, 1H, -CONH-), 8.32 (br s, 1H, -NH-), 8.01 (br s, 2H, -NH-), 7.96 (m, 1H, Ar-H), 7.93 (m, 1H, Ar-H), 7.84 (m, 1H, Ar-H), 7.62 (m, 1H, Ar-H), 7.54 (m, 1H, Ar-H), 7.51 (m, 1H, Ar-H), 7.48 (m, 1H, Ar-H), 7.45 (m, 2H, Ar-H), 7.14 (m, 2H,Ar-H), 6.46 (br s, 2H, -NH-), 4.55 (m, 2H, -CH-), 4.52 (m, 1H, -CH-), 3.42(m, 1H, -CH2-), 3.30 (m, 2H, -CH2-), 3.18 (m, 1H, -CH2-), 3.12 (m, 1H, -CH2-), 2.63 (m, 2H, -CH2-), 2.48 (m, 1H, -CH-), 2.46 (t, J = 7.1 Hz, 6H, -CH2-), 2.45(m, 2H, -CH2-), 2.33 (m, 3H, -CH2-), 2.25 (m, 1H, -CH2-), 2.06 (m, 1H, -CH-), 2.05 (m, 1H, -CH2-), 1.76 (m, 1H, -CH2-), 1.73 (m, 2H, -CH2-), 1.62 (m, 2H, -CH2-), 1.53 (m, 1H, -CH2-), 1.31 (m, 1H, -CH2-), 1.25 (m, 1H, -CH2-).

[0061] Example 6 This embodiment provides a method for preparing a compound (LSFZ-06) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-06 was synthesized.

[0062] The NMR characterization of LSFZ-06 yielded the following results: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.18 (s, 1H),7.88 – 7.76 (m, 3H), 7.47 – 7.41 (m, 2H), 7.11 (dt, J = 7.9, 1.1 Hz, 2H), 6.52(t, J = 4.9 Hz, 1H), 4.35 (dt, J = 8.2, 6.0 Hz, 1H), 4.24 (dt, J = 9.2, 6.4 Hz, 1H), 4.13 (dt, J = 8.4, 5.8 Hz, 1H), 3.41 (d, J = 1.6 Hz, 4H), 3.10 (qd, J = 5.2,1.7 Hz, 2H), 2.93 – 2.84 (m, 2H), 2.82 – 2.70 (m, 4H), 2.70 – 2.61 (m, 13H), 2.61 – 2.44 (m, 12H), 2.44 – 2.15 (m, 12H), 2.03 – 1.29 (m, 18H).

[0063] Example 7 This embodiment provides a method for preparing a compound (LSFZ-07) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-07 was synthesized.

[0064] The LSFZ-07 was characterized by NMR, and the results are as follows: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.57 (s, 1H), 7.75 (d, J = 8.6 Hz, 1H), 7.66 (s, 0H), 7.44 (d, J = 7.9 Hz, 2H), 7.30 – 7.17 (m,10H), 7.11 (dt, J = 7.9, 1.0 Hz, 2H), 6.84 (t, J= 4.9 Hz, 1H), 4.53 (dt, J = 8.4, 6.2 Hz, 1H), 4.42 (dt, J = 8.8, 6.4 Hz, 1H), 3.41 (d, J = 1.6 Hz, 4H), 3.19 –2.93 (m, 6H), 2.93 – 2.84 (m, 2H), 2.82 – 2.66 (m, 7H), 2.66 – 2.61 (m, 10H), 2.61 – 2.51 (m, 6H), 2.51 – 2.25 (m, 11H), 2.01 – 1.80 (m, 8H), 1.77 – 1.60 (m, 6H), 1.60 – 1.53 (m, 6H), 1.53 – 1.41 (m, 4H), 1.41 – 1.30 (m, 6H).

[0065] Example 8 This embodiment provides a method for preparing a compound (LSFZ-08) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-08 was synthesized.

[0066] The LSFZ-08 was characterized by NMR, and the results are as follows: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.24 (s, 1H), 7.87 (t, J = 5.1 Hz, 1H), 7.73 (d, J = 8.6 Hz, 2H), 7.47 – 7.41 (m, 2H), 7.11(dt, J = 7.9, 1.1 Hz, 2H), 7.03 (dt, J = 8.7, 1.1 Hz, 4H), 6.84 (t, J = 4.9 Hz,1H), 6.75 – 6.69 (m, 4H), 6.14 (s, 2H), 4.42 (dt, J= 8.6, 6.6 Hz, 2H), 3.45 –3.34 (m, 6H), 3.18 – 3.05 (m, 2H), 3.05 – 2.95 (m, 4H), 2.93 – 2.84 (m, 2H),2.82 – 2.72 (m, 3H), 2.72 – 2.65 (m, 10H), 2.64 (d, J = 3.8 Hz, 2H), 2.64 –2.33 (m, 23H), 2.02 – 1.92 (m, 2H), 1.70 – 1.42 (m, 8H), 1.42 – 1.28 (m, 2H).

[0067] Example 9 This embodiment provides a method for preparing a compound (LSFZ-09) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-09 was synthesized.

[0068] The LSFZ-09 was characterized by NMR, and the results are as follows: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.18 (s, 1H), 7.87 (d, J = 8.6 Hz, 1H), 7.47 – 7.41 (m, 2H), 7.11 (dt, J = 7.9, 1.1 Hz, 2H), 4.27 (dt, J = 8.6, 5.7 Hz, 1H), 4.17 (dt, J = 18.7, 4.2 Hz, 2H), 3.86 (tt, J = 5.5, 4.2 Hz, 1H), 3.50 (ddt, J = 25.3, 12.5, 6.3 Hz, 2H), 3.41 (d, J = 1.6 Hz, 4H), 3.28 (dd, J = 8.1, 5.5 Hz, 1H), 3.18 (dd, J = 8.0, 5.4 Hz, 1H), 3.06 (dd, J= 12.5,4.2 Hz, 1H), 2.95 – 2.61 (m, 30H), 2.61 – 2.33 (m, 14H), 2.09 – 2.02 (m, 2H), 2.02 – 1.91 (m, 2H), 1.71 – 1.49 (m, 8H), 1.47 – 1.31 (m, 2H).

[0069] Example 10 This embodiment provides a method for preparing a compound (LSFZ-10) targeting prostate-specific membrane antigens. The synthetic route is shown below: Based on the above synthetic route, the corresponding product LSFZ-10 was synthesized.

[0070] The LSFZ-10 was characterized by NMR, and the results are as follows: 1 H NMR (500 MHz, DMSO- d 6 ) δ 9.28 (s, 1H), 7.90 (dd, J = 2.1, 0.6 Hz, 2H), 7.85 (d, J = 8.2 Hz, 2H), 7.47 – 7.41 (m, 2H), 7.33 (ddd, J = 8.2, 2.0, 0.6 Hz, 2H), 7.11 (dt, J = 7.9, 1.1 Hz, 2H), 6.69 (t, J =5.2 Hz, 1H), 3.41 (d, J = 1.6 Hz, 4H), 3.09 (q, J = 5.6 Hz, 2H), 2.93 – 2.84 (m,2H), 2.82 – 2.74 (m, 3H), 2.74 – 2.66 (m, 6H), 2.66 – 2.64 (m, 8H), 2.64 –2.61 (m, 2H), 2.61 – 2.46 (m, 9H), 2.46 – 2.29 (m, 7H), 2.02 – 1.42 (m, 26H), 1.42 – 1.30 (m, 2H).

[0071] Example 11 This embodiment provides a radionuclide conjugate targeting prostate-specific membrane antigens ( 18 F-LSFZ-0118 F-LSFZ-04 and 18 The preparation method of F-LSFZ-05 is as follows: Take 80 µL of 0.5 M sodium acetate solution with pH=4 and slowly add it to a solution containing 50 µL of compound LSFZ-01, LSFZ-04, or LSFZ-05 at a concentration of 1 µg / µL. Add 4 µL of AlCl3 solution, and then add 200 µL of freshly passed QMA column containing radioactive nuclides. 18 F's physiological saline solution, 100 o The reaction was heated under a C18 heating mantle for 15 min. After the reaction was complete, the mixture was cooled to room temperature and purified by a C18 column to prepare radionuclide conjugates targeting PSMA. 18 F-LSFZ-01 18 F-LSFZ-04 and 18 F-LSFZ-05.

[0072] Example 12 This embodiment provides a radionuclide conjugate targeting prostate-specific membrane antigens ( 177 Lu-LSFZ-04 and 177 The preparation method of Lu-LSFZ-05 is as follows: Take 8 µL of 0.5 M sodium acetate-acetic acid buffer solution and slowly add it to a solution containing 5 µL of compound LSFZ-04 or LSFZ-05 at a concentration of 1 µg / µL. Add 180 µL of physiological saline solution, 1 mg of gentianic acid, and 10 µL of radionuclide solution. 177 LuCl3, 95 o The reaction was heated under a heating mantle at C for 30 min. After the reaction was completed, the mixture was cooled to room temperature, and radionuclide conjugates targeting PSMA were prepared. 177 Lu-LSFZ-04 and 177 Lu -LSFZ-05.

[0073] Example 13 This embodiment provides a radionuclide conjugate targeting prostate-specific membrane antigens ( 131 The preparation method of I-LSFZ-02 is basically the same as that in Example 11, except that the radionuclide used is changed. 18 F is replaced with 131 I, prepared to obtain 131 I-LSFZ-02.

[0074] Example 14 This embodiment provides a radionuclide conjugate targeting prostate-specific membrane antigens ( 125The preparation method of I-LSFZ-03 is basically the same as that in Example 11, except that the compound used is replaced with LSFZ-03, and the radionuclide used is changed. 18 F is replaced with 125 I, prepared to obtain 125 I-LSFZ-03.

[0075] Example 15 This embodiment provides a radionuclide conjugate targeting prostate-specific membrane antigens ( 90 The preparation method of Y-LSFZ-02 is basically the same as that in Example 12, except that the compound used is replaced with LSFZ-02, and the radioactive nuclide solution used is changed. 177 LuCl3 was replaced with 90 YCl3 was prepared to obtain 90 Y- LSFZ-02.

[0076] Example 16 This embodiment provides a radionuclide conjugate targeting prostate-specific membrane antigens ( 64 The preparation method of Cu-LSFZ-03 is basically the same as that in Example 12, except that the compound used is replaced with LSFZ-03, and the radioactive nuclide solution used is changed. 177 LuCl3 was replaced with 64 CuCl2 was prepared to obtain 64 Cu-LSFZ-03.

[0077] Example 17 This embodiment provides a radionuclide conjugate targeting prostate-specific membrane antigens ( 111 The preparation method of In-LSFZ-05 is basically the same as that in Example 12, except that the radioactive nuclide solution used is changed. 177 LuCl3 was replaced with 111 InCl2, prepared to obtain 111 In- LSFZ-05.

[0078] Based on the methods of Examples 11-17 above, when the compound used is changed from LSFZ-06 prepared in Examples 6-10 to LSFZ-10, and / or the type of radionuclide used is changed... 99m Tc, 68 Ga、 64 Cu、 225 Ac、 137 Cs、 90 Sr、 153When Sm is used, other compounds and / or other nuclides can also be prepared in the same way to target PSMA with corresponding nuclide conjugates, which will not be listed in this invention.

[0079] Verification Example 1 This verification example conducted in vitro and in vivo stability experiments on the radionuclide conjugates targeting PSMA. The specific methods are as follows: Each radionuclide conjugate prepared in Examples 11 to 17 was added to phosphate-buffered saline (PBS), fetal bovine serum (FBS), and each radionuclide conjugate was injected into the tail vein of mice. The radiochemical purity was measured at different time points, and the in vitro stability after adding PBS and FBS and the in vivo stability after injection into mice were detected. The injection dose of the injected mice and the stability results 1 day after injection are shown in Table 1.

[0080] Table 1 As can be seen from the results in Table 1, the in vivo stability of the radionuclide conjugates prepared in each example is very good, all greater than 99%, especially... 8 F-LSFZ-04 18 F-LSFZ-05 177 Lu-LSFZ-04 and 177 Lu-LSFZ-05 exhibits the best stability, exceeding 99.5%.

[0081] The in vitro stability of the radionuclide conjugates prepared in each example was also very good, among which 18 The in vitro and in vivo stability results of F-LSFZ-04 in FBS and PBS are shown in [reference needed]. Figure 1 , 18 The in vitro and in vivo stability results of F-LSFZ-05 in FBS and PBS are shown in [reference needed]. Figure 2 .from Figure 1 , Figure 2 It can be seen that phosphate-buffered saline (PBS) is close to the physiological pH value, and radionuclide conjugates targeting PSMA generally exhibit extremely high stability (>99%) in PBS; while fetal bovine serum (FBS) contains various enzymes and cellular components, which can more realistically simulate the complex biological environment in vivo. The results show that... 18 The stability of F-LSFZ-04 in FBS is basically the same as that in PBS. 177 The stability of Lu-LSFZ-04 in FBS was slightly lower than that in PBS. This indicates that the biomolecules in serum did not significantly affect the stability of the PSMA-targeting radionuclide conjugate, suggesting that the PSMA-targeting radionuclide conjugate has good tolerability in serum.

[0082] Verification Example 2 This validation example demonstrates the cellular uptake of PSMA-targeting radionuclide conjugates in LNCaP cells. The specific method is as follows: Take LNCaP cells in the logarithmic growth phase and use 1×10 5 Cells were seeded per well into 24-well plates and incubated for 24 hours until cell adhesion. All wells were then divided into three groups according to the experimental purpose: the experimental groups were treated with 1 mL of different nuclide-labeled conjugates containing 1 μCi (…). 18 F-LSFZ-04 18 F-LSFZ-05 177 Lu-LSFZ-04 177 Complete culture medium containing Lu-LSFZ-05; the blocking group was treated with 1 mL of different nuclide-labeled conjugates containing 1 μCi. 18 F-LSFZ-04 18 F-LSFZ-05 177 Lu-LSFZ-04 177 Complete culture medium containing Lu-LSFZ-05 and 300 times the blocking dose of 2-PMPA; a control group was also prepared by adding 1 mL of a radionuclide-labeled conjugate containing 1 uCi ( 177 Lu-PSMA-617). 24-well plates were incubated at 37°C. After incubation for 1 h, 2 h, and 4 h, the plates were removed, and the supernatant was transferred to the corresponding supernatant release tube. The plates were then gently washed twice with pre-chilled PBS at 4°C, and the wash liquid was collected into the same supernatant release tube. Sodium hydroxide solution (1M, 1 mL) was added to the cell wells after supernatant removal, and the plates were incubated at 37°C for 10 min to treat the adherent cells. After treatment, sodium hydroxide solution was transferred to the corresponding cell release tube, and the cell wells were gently washed twice with pre-chilled PBS at 4°C, and the wash liquid was collected into the same cell release tube. Each time point in each group had n=5 cells. Cell counts were performed using a PerkinElmer Wizard2 gamma counter. The cell uptake rate per well at each time point was calculated as: [cell counts per minute / (supernatant counts per minute + cell counts per minute)] × 100%. The cell uptake results are shown below. Figure 3 As shown, LNCaP cells can be seen to... 18 F-LSFZ-04 18 Intake of F-LSFZ-05 steadily increased within 4 hours. Figure 3 A), regarding 177 Lu-LSFZ-04 177 The uptake of Lu-LSFZ-05 steadily increased within 48 hours and was significantly better than that of other drugs. 177Lu-PSMA-617 (48h: 11.2±0.6%, 11.6±0.8%, 6.2±0.7%) ( Figure 3 B). No uptake of the radionuclide-labeled conjugate was observed in LNCaP cells of the blocking group.

[0083] Compared to the previously reported compound 3p-C-NETA-ePSMA-16, its labeled 111 The cellular uptake of In-3p-C-NETA-ePSMA-16 in PSMA-highly expressed LS174T cells was 1.40 AD / 10. 6 1 cell, while the control group 111 The result for In-PSMA-617 was 4.83 AD / 10. 6 In 100 cells, 3p-C-NETA-ePSMA-16 showed lower uptake results.

[0084] Verification Example 3 This validation example demonstrates a competitive binding assay of PSMA-targeting compounds in LNCaP cells. The specific method is as follows: Take LNCaP cells in the logarithmic growth phase and use 2×10⁻⁶ cells... 4 Seed cells / well into 96-well plates and incubate for 24 hours until cells are fully adhered. Divide all wells into 3 groups according to the experimental purpose, discard the old culture medium, and add 150 μL of culture medium at a ratio of 1:10. -4 M to 10 - 12 Complete culture medium containing cold LSFZ-04, LSFZ-05, and PSMA-617 at M concentration gradients; then add 100 μL of a solution containing 1 μCi to each well. 177 Lu-PSMA-617 cells were incubated at 37°C. After 4 hours of incubation, the 96-well plate was removed, the supernatant was discarded, and the cells were gently washed twice with pre-chilled PBS (4°C). Sodium hydroxide solution (1M, 100 μL) was added to the wells after the supernatant was removed, and the plates were incubated at 37°C for 10 minutes to treat the adherent cells. After treatment, sodium hydroxide solution was transferred to the corresponding cell group's radioimmunoassay tube, and the wells were gently washed twice with pre-chilled PBS (4°C). Cells were collected into the same cell group's radioimmunoassay tube. Each group had n=5 cells at each time point. Cell counting was performed using a PerkinElmer Wizard 2 γ-ray counter. The results of the competitive binding of cells are shown below. Figure 4As shown, the IC50 values ​​of LSFZ-04, LSFZ-05, and PSMA-617 were 13.23 nM, 7.44 nM, and 16.31 nM, respectively. The compounds LSFZ-04 and LSFZ-05 prepared in this invention have a better affinity for PSMA than PSMA-617.

[0085] Compared to the previously reported compound 3p-C-NETA-ePSMA-16, its IC50 result for PSMA is also high, but it is only 1 / 5 of that of PSMA-617. This indicates that the PSMA-targeting compound prepared in this invention has better potential than existing technologies.

[0086] Verification Example 4 This validation example demonstrates the pharmacokinetic analysis of the PSMA-targeting radionuclide conjugate in normal mice. The specific methods are as follows: Balbc mice were randomly divided into several groups, with 3 mice in each group. Each group of mice was injected with a different [specific treatment] via the tail vein. 18 F-labeled nuclide conjugates ( 18 F-LSFZ-04 18 F-LSFZ-05 was administered at 1 min, 3 min, 5 min, 10 min, 15 min, 30 min, 60 min, 120 min, and 180 min after injection. Blood samples were collected, weighed, and radioactivity counts were measured. After decay correction, the percentage injection dose rate (%ID / g) per gram of blood was calculated. The results are as follows: Figure 5 , Figure 6 As shown, 18 The biodistribution half-life of F-LSFZ-04 in vivo is 0.71 min, and the blood clearance half-life is 30.49 min. 18 The in vivo biodistribution half-life of F-LSFZ-05 is 2.52 min, and the blood clearance half-life is 47.47 min, indicating that the radionuclide conjugate prepared in this invention has a significantly faster metabolic rate and clearance half-life compared with the prior art.

[0087] 18 F-LSFZ-04 and 18 The biodistribution of F-LSFZ-05 in normal mice 5 min, 15 min, 30 min, 60 min, 120 min, 240 min, and 360 min after injection is shown in the figure. Figure 7 , Figure 8 This indicates that the vast majority of it is ultimately excreted relatively well through the kidneys.

[0088] At the same time, verification 18 F-LSFZ-04 and 18The hydrophilicity of F-LSFZ-05 is determined by the following method: partition coefficient (LogD). 7.4 The determination was performed using the shake-flask method, and the experiment was repeated three times. 18 F-LSFZ-04 and 18 F-LSFZ-05 was added to a mixture of phosphate-buffered saline (PBS, 0.01 M, pH 7.4) and n-octanol (500 μL). The mixture was vigorously vortexed and centrifuged for 15 minutes to achieve phase separation. Samples (3 aliquots, 10 μL each) were taken from each phase and counted using a PerkinElmer Wizard 2 gamma counter. LogD 7.4 The value is calculated using the following formula: LogD 7.4 = log [(count of n-octanol phase) / (count of aqueous phase)]. The results of the determined lipid-water partition coefficient can be found in [reference needed]. Figure 9 and Figure 10 , 18 The lipid-water partition coefficient of F-LSFZ-04: LogP = -2.673, LogD 7.4 = -2.961; 18 The lipid-water partition coefficient of F-LSFZ-04: LogP = -2.878, LogD 7.4 = -2.943. This indicates that the nuclide conjugate formed by this linker has excellent hydrophilicity.

[0089] Verification Example 5 This verification example involved a radionuclide conjugate targeting PSMA. 18 F-LSFZ-04 and 18 PET / CT imaging study of F-LSFZ-05 in LNCaP tumor-bearing mice. Specific methods are as follows: SPF-grade NSG mice, female, 5 weeks old, were acclimatized in the animal facility for two days before receiving a subcutaneous injection of 0.1 mL (1×10⁻⁶) of LNCaP prostate cancer cells into the right axilla. 7 (cells / mL dispersed in HBSS), continued feeding after injection until the solid tumor mass grew to approximately 350-600 mm. 3 At that time, LNCaP tumor-bearing mice were injected with approximately 150 µCi / 0.2 mL via the tail vein. 18 F-LSFZ-04 or 18F-LSFZ-05. LNCaP-bearing mice were anesthetized at 1, 2, and 4 hours post-injection. The deeply anesthetized mice were then placed in a supine position on a PET / CT scanning table for continuous PET and CT image acquisition. Mice in the blockade group received an additional 300-fold molar dose of 2-PMPA, and were anesthetized 60 minutes post-injection for PET and CT image acquisition. In vivo Micro PET / CT imaging results and tumor uptake values ​​in LNCaP-bearing mice are shown below. Figure 11 The results showed 18 F-LSFZ-04 or 18 F-LSFZ-05 showed significant uptake in PSMA-positive tumors, with a rapid metabolic rate in non-target organs, resulting in good imaging effects.

[0090] Verification Example 6 This validation example analyzed the biodistribution of PSMA-targeting radionuclide conjugates in LNCaP tumor-bearing mice. The specific methods are as follows: LNCaP-bearing mice were randomly divided into several groups, with 3 mice in each group. Each group of mice was injected with different [specific drugs / treatments] via the tail vein. 18 F-labeled nuclide conjugates ( 18 F-LSFZ-04 18 Mice in the F-LSFZ-05 group were sacrificed at 60, 120, and 240 minutes after injection. Mice in the blockade group received an additional 300 molar dose of 2-PMPA and were sacrificed 60 minutes after injection. Tumor and major normal organ tissues from the mice were weighed and radioactivity counts were measured. After decay correction, the percentage of injected dose per gram of tissue (%ID / g) was calculated. The results are as follows: Figure 12 , Figure 13 As shown.

[0091] Verification Example 7 This verification example involved a radionuclide conjugate targeting PSMA. 177 Lu-LSFZ-04 and 177 SPECT imaging study of Lu-LSFZ-05 in LNCaP tumor-bearing mice. Specific methods are as follows: Using LNCaP-bearing mice derived from Example 3, the solid tumor masses were allowed to grow to approximately 350-600 mm. 3 At that time, LNCaP tumor-bearing mice were injected with approximately 800 µCi / 0.2 mL via the tail vein. 177 Lu-LSFZ-04 and 177Lu-LSFZ-05. LNCaP-bearing mice were anesthetized at 1h, 4h, 24h, 48h, 72h, 96h, and 120h post-injection, and SPECT imaging was performed on the deeply anesthetized LNCaP-bearing mice. The in vivo SPECT imaging results of the LNCaP-bearing mice are as follows: Figure 14 , Figure 15 As shown, the results are... 177 Lu-LSFZ-04 or 177 Lu-LSFZ-05 can remain in PSMA-positive tumors for a longer period of time, and its metabolic rate in non-targeted normal organs is fast, resulting in less damage to normal tissues.

[0092] Verification Example 8 This verification example involved a radionuclide conjugate targeting PSMA. 177 Lu-LSFZ-04 and 177 In vivo tumor therapy study of Lu-LSFZ-05. Specific methods are as follows: Using LNCaP-bearing mice derived from the same verification example 3, mice were randomly divided into 6 groups. The solid tumor masses were allowed to grow to approximately 50-150 mm. 3 At that time, for the first group ( 177 Lu-LSFZ-04-29.6 MBq mice were administered approximately 800 µCi / 0.2 mL via tail vein injection. 177 Lu-LSFZ-04, for the second group ( 177 Lu-LSFZ-05-29.6 MBq mice were injected with approximately 800 µCi / 0.2 mL of [a specific drug / method]. 177 Lu-LSFZ-05, for the third group ( 177 Lu-LSFZ-04-14.8 MBq mice were administered approximately 400 µCi / 0.2 mL via tail vein injection. 177 Lu-LSFZ-04, for the fourth group ( 177 Lu-LSFZ-05-14.8 MBq mice were administered approximately 400 µCi / 0.2 mL via tail vein injection. 177 Lu-LSFZ-05, for the fifth group ( 177 Lu-PSMA-617-14.8 MBq mice were administered approximately 400 µCi / 0.2 mL via tail vein injection. 177 Lu-PSMA-617 was administered to group 6 (NS) mice via injection of 0.2 mL of physiological saline, marked as day 0 of treatment. Tumor volume and mouse weight were recorded on day 0, and subsequently monitored every 2 days for evaluation. 177 Lu-LSFZ-04 and 177The in vivo therapeutic effect of Lu-LSFZ-05 on PSMA-positive tumors. Tumor size and mouse body weight changes are shown in the curves. Figure 16 As shown. Two weeks after administration, the mice were sacrificed and blood was collected. Simultaneously, LNCaP subcutaneous tumors, and vital organs such as the heart, liver, spleen, lungs, and kidneys were dissected and removed. Gross images of the tumors are shown below. Figure 17 As shown in the figure. This result demonstrates that the radionuclide conjugates constructed from the hydrophilic linker structure provided by this invention have excellent therapeutic effects. The heart, liver, spleen, lung, and kidneys of mice from groups one, two, and six were stained with hematoxylin and eosin (H&E) to assess the toxic effects of radioligand therapy on the organs. The results are as follows. Figure 18 As shown. Blood routine tests, liver function tests, and kidney function tests were performed on the blood of mice in groups 1, 2, and 6 to assess the toxic effects of radioligand therapy on blood counts. The results are as follows. Figure 19 As shown in the figure. This result demonstrates that the nuclide conjugates constructed from the hydrophilic linker structure provided by this invention have good safety.

[0093] The linkers, compounds, and radionuclide conjugates provided in the context of this invention can be prepared into pharmaceutically acceptable salts, prodrugs, and esters through appropriate processes, or they can be mixed with pharmaceutical carriers in proportion to form pharmaceutical compositions, adapting to different administration scenarios and clinical needs.

[0094] For example, pharmaceutically acceptable salts are typically obtained through conventional acid-base reactions of linkers, compounds, or radionuclide conjugates with inorganic acids, organic acids, inorganic bases, or organic bases. Following the reaction, crystallization, filtration, and purification steps yield the target salt product, commonly including hydrochlorides, sulfates, phosphates, acetates, maleates, sodium salts, potassium salts, and ammonium salts. This type of process optimizes the physicochemical properties of the active ingredient. Another example is prodrugs, prepared by chemically modifying the active groups of linkers, compounds, or radionuclide conjugates. Modification methods, such as acylation and alkylation, are chosen based on the type of active group. After entering the body, the modified product undergoes endogenous enzymatic hydrolysis and other metabolic processes to be converted into the biologically active original substance. Yet another example is esters, prepared through esterification reactions of the active groups in linkers, compounds, or radionuclide conjugates with carboxylic acids or alcohols. Following the reaction, separation and purification remove byproducts. The resulting esters can adjust the lipid-water partition coefficient of the active ingredient, thereby optimizing its distribution and metabolic efficiency in vivo. For example, it can also be prepared into a pharmaceutical carrier. The pharmaceutical carrier is selected and matched according to the requirements of the route of administration. The carrier components such as diluents, binders, disintegrants, and solubilizers are mixed with the active ingredients in proportion. After processing such as stirring, granulation, and drying, a uniform and stable drug composition is formed, which is suitable for different forms of administration such as oral administration and injection.

[0095] The linkers, compounds, or radionuclide conjugates provided in this invention can also be used as active ingredients in the preparation of injectable formulations. The active ingredient is first dissolved in a solvent such as water for injection or physiological saline, and then excipients such as solubilizers and stabilizers are added to adjust the system stability. This formulation is suitable for intravenous, arterial, and intramuscular injection routes, enabling the active ingredient to rapidly enter the bloodstream for targeted delivery systemically or locally. During injection preparation, the active ingredient, solvent, and excipients are thoroughly mixed and stirred until homogeneous. The pH and osmotic pressure of the system are adjusted to a suitable range. The solution is then filtered for sterilization, filled, and sealed. After sterilization and clarity and content testing, a qualified injectable solution is obtained, suitable for intravenous, arterial, and intramuscular injection routes. After preparation, the injectable solution is dispensed into sterile injection containers according to specifications, sealed, and stored in a light-protected, temperature-controlled environment. Regular testing of radionuclide activity and component stability ensures the formulation can be used normally within its shelf life.

[0096] In the context of this invention, the linkers, compounds, and radionuclide conjugates are used to prepare imaging diagnostic reagents through radionuclide labeling and targeted assembly. By leveraging the radioactive signal of the radionuclide and the targeting ability of the compound, image capture and assessment of lesion areas are achieved. After the radionuclide is conjugated with the compound and linker, it is separated and purified by methods such as chromatography and centrifugation to remove unlabeled radionuclides and reaction impurities. After activity testing and sterilization, the diagnostic reagent is obtained. In use, the radionuclide signal is captured by imaging equipment to form lesion images.

[0097] The linkers, compounds, or radionuclide conjugates provided in the context of this invention can also be used to prepare reagents for diagnosing prostate cancer and / or its metastases. In the preparation process, compounds that can specifically bind to prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) are selected, and they are stably conjugated to radionuclides through linkers. After the reaction, the reaction system is optimized to improve the conjugation efficiency, so that the radionuclides can accurately aggregate with the compounds at the primary and metastatic lesions of prostate cancer. Then, impurities are removed through purification.

[0098] The linkers, compounds, or radionuclide conjugates provided in the context of this invention can also be used to prepare medicaments for the treatment of prostate cancer and / or its metastases.

[0099] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A compound targeting prostate-specific membrane antigens, characterized in that, The structure of the compound is shown below: 、 、 、 、 、 、 、 、 、 。 2. A radionuclide conjugate targeting prostate-specific membrane antigens, characterized in that, The nuclide conjugate consists of the compound described in claim 1 and a radionuclide.

3. The radionuclide conjugate targeting prostate-specific membrane antigen according to claim 2, characterized in that, The radionuclides are selected from 18 F, 99m Tc, 68 Ga、 64 Cu、 111 In、 90 Y、 225 Ac、 137 Cs、 90 Sr、 125 I, 131 I, 153 Sm and 177 At least one of the Lu nuclides.

4. The radionuclide conjugate targeting prostate-specific membrane antigen according to claim 3, characterized in that, The radionuclides are selected from 18 F or 177 Lu.

5. A method for preparing a radionuclide conjugate targeting prostate-specific membrane antigen according to claim 2, characterized in that, The process includes the following steps: adding the compound of claim 1 and a salt solution containing a radionuclide to a solution containing a NaAc buffer system, and heating the solution to react, thereby obtaining the radionuclide conjugate.

6. The use of a compound according to claim 1 or a radionuclide conjugate according to any one of claims 2-3 in the preparation of imaging diagnostic reagents.

7. The use of a compound according to claim 1 or a radionuclide conjugate according to any one of claims 2-3 in the preparation of a medicament for treating prostate cancer or its metastases.

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