Tumor targeted imaging compound as well as preparation method, composition and application thereof

Abstract

The invention discloses a tumor targeted imaging compound and a preparation method, a composition and application thereof, the structural general formula of the compound is shown in the following formula I: X-Y-Z formula (I), X is a target head, Y is a linker, and Z is a dye. According to the compound for tumor targeted imaging, fluorescence imaging can be carried out through targeted tumor, so that the distribution condition of tumor tissues is determined according to the fluorescence imaging condition, and the state of a disease is further diagnosed or determined or an operation is carried out; the compound is obtained through specific design and has the advantages of being good in targeting performance, high in affinity with tumor tissue, high in signal response speed, high in resolution ratio and the like, and therefore the positive incision edge rate and the false positive rate can be effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of biological detection technology, and relates to a compound, its preparation method, composition and application, specifically to a compound for tumor-targeted imaging, its preparation method, composition and application. Background Technology

[0002] Prostate cancer is a tumor caused by the malignant proliferation of prostate epithelial cells. It is the most common malignant tumor of the male genitourinary system and may cause urinary abnormalities, pelvic discomfort, and erectile dysfunction. Prostate cancer is also a global health concern. Reports from the International Agency for Research on Cancer (IARC) of the World Health Organization and its Global Cancer Statistics (GLOBOCAN) database show that the number of new cancer cases worldwide is increasing year by year. my country still has the highest cancer incidence and mortality rates globally, posing a serious threat to the health of its people.

[0003] Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein composed of 750 amino acids. After glycosylation, its molecular weight is greater than 100 kDa. Besides the prostate, it is also expressed in non-prostate tissues such as the duodenum, kidneys, salivary glands, neuroendocrine system, and proximal renal tubules. However, compared to normal tissues, PSMA expression in prostate cancer tissues can be 100-1000 times higher, and it is also overexpressed in cancerous lymph nodes and bone metastases. PSMA expression is very high in prostate cancer tumors, occurring at almost all stages of the disease. In an immunohistochemical (IHC) analysis, PSMA expression was detected in 94% of prostate cancer samples. Furthermore, increased PSMA expression is associated with tumor grade, pathological stage, and biochemical recurrence. The transmembrane conformation of PSMA allows it to internalize binding agents via endosome complexes, which is highly advantageous for successful ligand targeting.

[0004] Surgical intervention is the primary treatment for prostate cancer, and procedures can be performed openly, laparoscopically, or robotically. Radical prostatectomy aims to completely remove the tumor while preserving urinary continence and, if possible, erectile function. While current techniques can help identify larger lesions preoperatively and postoperatively, limitations prevent real-time tumor localization during surgery and accurate assessment of surgical margins. Clinical statistics show that 20% to 48% of prostate cancer patients leave the operating room with positive tumor margins, directly related to biochemical recurrence (BCR) and cancer management; approximately 32% to 38% of patients experience BCR within 5 years. Furthermore, in prostate cancer, the most common sites of BCR and positive tumor margins are the posterolateral dorsolateral region and the apex of the prostate, areas closely related to nerves responsible for erectile function and urinary control. Because erectile dysfunction and urinary incontinence are the main potential side effects of prostatectomy, surgeons may prefer to preserve the tissues and nerves surrounding the posterolateral dorsolateral region and the apex of the prostate to maintain the patient's quality of life. Therefore, carefully preserving these areas may result in the retention of tumor tissue, increasing the risk of biomarker-related complete resection (BCR). Fluorescence-guided intraoperative imaging techniques can help reduce positive tumor margins and identify occult metastatic lymph nodes, thereby improving the prognosis of prostate cancer patients. For intraoperative imaging in prostate cancer, prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein with an extracellular binding site. The extracellular region accounts for 95% of PSMA, making it a specific molecular target for small molecules and antibodies. PSMA expression levels are significantly upregulated in the cell membranes of almost all prostate cancer (PCa) cells, with only 5%–10% of PCa lesions showing negative PSMA expression. The PSMA expression level in PCa is 100–1000 times higher than in non-lesioned prostate tissue.

[0005] With the widespread adoption of laparoscopic surgery and the rapid development of surgical robots, the demand for precise intraoperative localization and identification is increasing. Compared to traditional open surgery, intraoperative fluorescence visualization technology has flourished thanks to the extensive use of fluorescence endoscopes, indocyanine green (ICG) fluorescent contrast agents, and fluorescence surgical navigation hardware. Intraoperative fluorescence imaging can provide real-time identification of blood vessels, tumors, lymph nodes, and nerves during surgery, offering new tools for precise target localization and finding the optimal surgical path. This reduces intraoperative bleeding and iatrogenic nerve injury, ensuring surgical safety, minimizing damage to major blood vessels and nerves, and ultimately shortening patients' post-operative recovery time. Currently, ICG remains the most widely used near-infrared contrast agent in clinical practice.

[0006] While ICG shows great potential in surgery, it also has several drawbacks: 1) it lacks tumor targeting and cannot specifically label tumor tissue; 2) it metabolizes rapidly with a half-life of 2-4 minutes, requiring repeated injections for contrast imaging during surgery; 3) it migrates to lower-level lymph nodes due to tissue diffusion, leading to inaccurate sentinel lymph node localization; 4) its chemical and photoinstability easily causes degradation; and 5) spillage contaminates the surgical field. These limitations severely restrict its application, and it has not been widely used for tumor and lymph node localization. Current research focuses on modifying ICG to prolong its fluorescence signal, improve tumor targeting, and enhance quantum yield and fluorescence stability. In a study exploring the impact of nanoparticle size on biodistribution and tumor accumulation, the authors developed ICG-lecithin-PEG core-shell nanoparticles with sizes of 39 nm, 68 nm, or 116 nm using nanoprecipitation, comparing the excretion time of free ICG with that of the nanoparticles. Fluorescence imaging showed that the nanoparticles had a longer retention time in vivo than free ICG, which was rapidly expelled and cleared. They also concluded that ICG-PLGA nanoparticles exhibited size-dependent tumor accumulation: 68 nm particles could easily pass through vascular pores and had a slower clearance rate than 39 nm particles (DOI: 10.1016 / j.biomaterials. 2014.04.019). Takahito Nakajima et al. designed a humanized anti-prostate-specific membrane antigen (PSMA) antibody (J591) conjugated to ICG. They obtained an activatable near-infrared (NIR) probe capable of detecting PSMA+ tumors with high contrast compared to PSMA-tumors for up to 10 days after injection of a low dose of the reagent. Its ability to be activated only in PSMA+ cells resulted in a very high tumor-to-background ratio (doi: 10.1021 / bc2002715). Wu et al. developed a nanoparticle in which ICG is encapsulated in a polymeric micelle core. The micelle is self-assembled from a poly(L-lysine)-poly(L-leucine) (PEG-PLL-PLLeu) amphiphilic PEG-peptide hybrid triblock copolymer, with PLLeu serving as the hydrophobic core and PEG as the hydrophilic shell. ICG is associated with the hydrophobic core through hydrophobic interactions and with the hydrophilic head through electrostatic attraction. Compared to free ICG, PEG-PLL-PLLeu-ICG micelles significantly improved quantum yield and fluorescence stability (DOI: 10.1021 / bm400839b).

[0007] Near-infrared fluorescence imaging is widely used in departments such as urology, gynecology, general surgery, and thoracic surgery, but its usage is relatively low in other departments. The main reason for this is the scarcity of fluorescence imaging agents that can be used in conjunction with near-infrared fluorescence imaging. ICG is currently the most widely used NIR fluorescence imaging agent in clinical practice, but its inherent limitations severely restrict its application. Currently, only two tumor-targeting fluorescence imaging agents are approved for marketing globally: Cytalux and LUMISIGHT. Cytalux is suitable for intraoperative auxiliary diagnosis of adult ovarian and lung cancer, while LUMISIGHT is suitable for intraoperative auxiliary diagnosis of adult breast cancer. Currently, no near-infrared fluorescence imaging agent has been approved for intraoperative auxiliary diagnosis of prostate cancer. OTL78 (the compound shown in Figure 25 of patent 201780067507.0) is still in the early stages of clinical trials, and its efficacy and safety require further confirmation through more clinical trials.

[0008] Therefore, based on the clinical needs of precision diagnosis and treatment, it is particularly important to develop near-infrared fluorescent imaging agents that can actively target tumor tissue and be used in conjunction with near-infrared fluorescence lenses to help identify tumors expressing PSMA, such as prostate cancer lesions during surgery, and effectively reduce the positive margin rate and false positive rate. Summary of the Invention

[0009] The purpose of this invention is to provide a compound for tumor-targeted imaging, its preparation method, composition, and application, which can actively target PSMA and be used in conjunction with a near-infrared fluorescence lens to help identify tumor lesions during surgery, such as prostate cancer, thereby effectively reducing the positive margin rate and false positive rate.

[0010] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution:

[0011] On one hand, the present invention provides a compound for tumor-targeted imaging, the general structural formula of which is shown in Formula I below:

[0012] XYZ type (Ⅰ)

[0013] Wherein, X is the target head, and the target head is the following structure or its alkali metal salt (preferably Na salt).

[0014] , which is a group formed from Euk and its analogues;

[0015] It is a group formed from DUPA and its analogues;

[0016] Y represents a connector, which is selected from one of the following structures:

[0017] , , , Or its alkali metal salt, wherein n=2~12, or its alkali metals, , ;

[0018] Z represents a dye, which is selected from groups formed by the following structures: SO456 or IRDye800 and their analogues.

[0019] It is a group formed by SO456 and its analogues;

[0020] It is a group formed by IRDye800 and its analogues.

[0021] In one or more embodiments of the present invention

[0022] The connector is Or its alkali metal salt v, where n = 2~12.

[0023] In one or more embodiments of the present invention, n = 5~10, preferably 5~7.

[0024] In one or more embodiments of the present invention, the compound is compound A, compound B, compound C, compound D, compound E, compound F, and compound G, wherein the structural formula of compound A is shown below:

[0025] (Compound A);

[0026] The structure of compound B is shown in the following formula:

[0027] (Compound B);

[0028] The structure of compound C is shown in the following formula:

[0029] (Compound C); The structure of compound D is shown in the following formula:

[0030] (Compound D);

[0031] The structure of compound E is shown in the following formula:

[0032] (Compound E);

[0033] The structure of compound F is shown in the following formula:

[0034] (Compound F);

[0035] The structure of compound G is shown in the following formula:

[0036] (Compound G).

[0037] On the other hand, the present invention also provides a method for preparing the above-mentioned tumor-targeting imaging compound, comprising the following steps:

[0038] 1) First, a compound 1 consisting of a target X and a linker Y is formed through a reaction;

[0039] Preferably, compound 1 is obtained by a method comprising the steps of: first synthesizing linker Y, and then reacting the linker with target X; or

[0040] The compound 1 is obtained by a method comprising the following steps: first, reacting the Y1 substructure of connector Y with the target X to obtain compound 11, which is connected to the target by the Y1 substructure; then reacting compound 11 with the Y2 substructure of connector Y to obtain compound 1 of the target X and connector Y.

[0041] 2) Compound 1 is then reacted with dye Y to form a compound for tumor-targeted imaging, thus obtaining the desired product;

[0042] Preferably, compound 1 is any of the following compounds:

[0043] , , , , , , .

[0044] In one or more embodiments of the present invention, in step 2), the dye is SO456, IRDye800 and the like;

[0045] Preferably, when the dye is IRDye800 or an analogue, the compound 1 and the dye are reacted in a buffer solution at pH 7.2-9.0 and room temperature for 1.5-3 hours, preferably at pH 8.4 and room temperature for 2 hours.

[0046] Preferably, when the dye is SO456 or an analogue, the compound 1 reacts with the dye in a sodium carbonate solution at 70-75°C for 0.5-1.5 hours, preferably 1 hour.

[0047] In another aspect, the present invention also provides a tumor-targeted imaging composition, comprising the above-mentioned compound and excipients, wherein the excipients are preferably pharmaceutically acceptable carriers, excipients or diluents.

[0048] In another aspect, the present invention also provides a tumor-targeted imaging kit, comprising the above-mentioned tumor-targeted imaging compounds.

[0049] In another aspect, the present invention also provides the application of the above-mentioned tumor-targeting imaging compound, composition or kit in the preparation of a fluorescent imaging agent.

[0050] In another aspect, the present invention also provides the application of the above-mentioned tumor-targeting imaging compound, composition or kit in the preparation of a drug for intraoperative tumor detection, specifically the application in a drug for performing fluorescence imaging to diagnose, determine or perform surgery, preferably, the tumor being a PSMA-expressing disease, such as prostate cancer.

[0051] In another aspect, the present invention also provides a method for diagnosing or determining a disease state or performing surgery through tumor-targeted imaging, comprising administering the above-mentioned tumor-targeted imaging compound, composition or kit to a subject or cell population suffering from a tumor, and determining the distribution of tumor tissue by fluorescence imaging, thereby diagnosing or determining a disease state or performing surgery.

[0052] Preferably, the tumor is a disease related to the expression of PSMA, such as prostate cancer.

[0053] Compared with existing technologies, the tumor-targeting imaging compounds of this invention can perform fluorescence imaging on target tumors, thereby determining the distribution of tumor tissue based on the fluorescence imaging, and further diagnosing or determining the disease status or performing surgery. These compounds, obtained through specific design, have advantages such as good targeting, high affinity for tumor tissue, fast signal response, and high resolution, thus effectively reducing the positive margin rate and false positive rate. Specifically, experiments have shown that the seven compounds currently provided by this invention are expected to specifically bind to tumor cells overexpressing PSMA, such as prostate tumor cells, in vivo, achieving the goal of illuminating the tumor. Due to their superior pharmacokinetic characteristics, their effect in distinguishing tumor tissue from normal tissue is significantly better than that of known compounds DGPR1008 and OTL78. It is expected that this clinical effect can be demonstrated at doses lower than DGPR1008 and OTL78, with potentially higher safety. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1The tumor background ratio of each compound in the 22Rv1 prostate cancer subcutaneous tumor-bearing mouse model of the present invention (Example 8);

[0056] Figure 2 The values ​​represent the tumor-to-normal tissue (T / P) ratios of each compound in the 22Rv1 model of Example 8 of the present invention, where 1-7 represent compound AG, 8 represents compound 8, and 9 represents compound 9. Detailed Implementation

[0057] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention are clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0058] Unless otherwise specified, all reagents and materials used in this article are available from legitimate sources.

[0059] Unless otherwise specified, “DUPA-FITC” in this article refers to “a conjugate of the DUPA group and the visible light dye FITC”.

[0060] Unless otherwise specified, all "BALB / c nude mice" mentioned in this article were purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd.

[0061] Example 1. Synthesis of Compound A

[0062]

[0063] Step 1: A03 Synthesis

[0064]

[0065] Weigh A01 (500 mg, 1.02 mmol) and A02 (284 mg, 1.23 mmol), add them to a 50 mL single-necked flask, add DMSO (Dimethyl sulfoxide) (30 mL) to dissolve them; add HTAU (2-(7-Azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate, 2-(7-azabenzotriazol)-N,N,N',N'-tetramethyluronium hexafluorophosphate) (468 mg, 1.23 mmol) and DIEA (N,N-Diisopropylethylamine, N,N-diisopropylethylamine) (263 mg, 2.04 mmol), stir for 2 h, after the reaction is complete, add the reaction solution to MTBE (Methyltert-Butyl Ether), centrifuge, and dry to obtain A03 (250 mg, yield 35%).

[0066] Step 2: A04 Synthesis

[0067]

[0068] Solid A03 (200 mg, 0.29 mmol) was dissolved in DCM (dichloromethane) (20 mL), and TFA (trifluoroacetic acid) (4 mL) was added. The mixture was stirred at room temperature for 2 h, and then saturated sodium carbonate (20 mL) solution was added. The mixture was separated, dried, and evaporated to dryness to obtain solid compound A04 (125 mg crude product, yield calculated as 100%).

[0069] Step 3: Synthesis of Compound A

[0070]

[0071] Dissolve IR Dye 800 NHS (40 mg, 0.036 mmol) in 10 ml of buffer solution (pH=8.4), and add the solution of A04 (15 mg, 0.036 mmol) dissolved in 10 ml of buffer solution (pH=8.4) to the above solution. React at room temperature for 2 h.

[0072] Post-processing: Preparation, lyophilized to obtain 10 mg of blue-green solid compound A, yield 18%, purity 96.8%, MS: [M-4Na+4H+2H] 2+ =729.23.

[0073] Example 2. Synthesis of Compound B

[0074]

[0075] Step 1: B02 Synthesis

[0076]

[0077] The following were added: bromobenzaldehyde (200 mg, 1.08 mmol), BO1 (580 mg, 1.19 mmol), and NaBH(OAc). 3| Sodium triacetoxyborohydride (275 mg, 1.3 mmol) was added sequentially to an ethyl acetate solution (5 mL) at room temperature. The reaction mixture was stirred at room temperature for 24 h. The solution was diluted with water (10 mL) and then extracted with EtOAc (ethyl acetate) (3 × 10 mL). The organic layer was rotary evaporated to obtain the crude product. Purification by silica gel column chromatography using petroleum ether / ethyl acetate (1:1) as the eluent gave solid BO2 (200 mg, 28% yield).

[0078] Step 2: B04 Synthesis

[0079]

[0080] Weigh BO2 (350 mg, 0.53 mmol) and BO3 (148 mg, 0.64 mmol), add them to a 25 mL single-necked flask, and dissolve them in DMSO (15 mL). Add HTAU (244 mg, 0.64 mmol) and DIEA (137 mg, 1.06 mmol), stir for 2 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and freeze-dry to obtain white solid BO4 (200 mg, yield 43%).

[0081] Step 3: B05 Synthesis

[0082]

[0083] Solid BO4 (200 mg, 0.23 mmol) was dissolved in DCM (20 mL), TFA (4 mL) was added, and the mixture was stirred at room temperature for 2 h. Saturated Na2CO3 (20 mL) solution was added, and the mixture was separated, dried, and evaporated to dryness to obtain solid compound BO5 (150 mg crude product, yield calculated as 100%).

[0084] Step 4: Synthesis of Compound B

[0085]

[0086] Dissolve IR Dye 800 NHS (40 mg, 0.036 mmol) in 10 mL of buffer solution (pH=8.4), and dissolve B05 (21 mg, 0.036 mmol) in 10 mL of buffer solution (pH=8.4). Add the solution to the above solution and react at room temperature for 2 h.

[0087] Post-processing: Preparation, lyophilized to obtain 13 mg of blue-green solid compound B, yield 22%, purity 97.8%, MS: [M-4Na+4H+2H] 2+ =776.29.

[0088] Example 3. Synthesis of Compound C

[0089]

[0090] Step 1: CO3 Synthesis

[0091]

[0092] Weigh CO1 (1 g, 6.25 mmol) and add it to a 50 mL single-necked flask. Add DCM (30 mL) to dissolve the CO2 (3.21 g, 12.5 mmol) and TEA (Triethylamine) (1.6 mg, 15.6 mmol). Stir for 2 h. After the reaction is complete, add saturated saline solution, separate the contents, dry, and evaporate to dryness to obtain solid compound CO3 (650 mg, yield 21%).

[0093] Step 2: CO5 Synthesis

[0094]

[0095] Weigh out CO3 (650 mg, 1.42 mmol) and add it to a 50 mL single-necked flask. Dissolve the CO3 in 24 mL of DCM. Add CO4 (694 mg, 1.42 mmol) and DIEA (367 mg, 2.84 mmol), stir for 2 h, and after the reaction is complete, add saturated saline solution. Separately dry the mixture and evaporate to dryness to obtain solid compound CO5 (400 mg, yield 36%). MS: [M+H] + =778.85.

[0096] Step 3: C07 Synthesis

[0097]

[0098] Weigh out CO5 (400 mg, 0.51 mmol) and add it to a 50 mL single-necked flask. Add DCM (24 mL) to dissolve it. Add CO6 (170 mg, 0.56 mmol) and DIEA (132 mg, 1.02 mmol). Stir for 2 h. After the reaction is complete, add the reaction solution to MTBE, centrifuge, and dry to obtain a solid. Dissolve the solid in DCM (20 mL), add TFA (4 mL), stir at room temperature for 2 h, add saturated sodium carbonate (20 mL) solution, separate the liquid, dry and evaporate to dryness to obtain solid compound CO7 (100 mg, yield 33%).

[0099] Step 4: Synthesis of Compound C

[0100]

[0101] Weigh CO7 (100 mg, 0.11 mmol) and add it to a 25 ml single-necked flask. Prepare a sodium carbonate aqueous solution (sodium carbonate (100 mg, 0.946 mmol)) and add it to the reaction flask. Add SO456 (107 mg, 0.11 mmol), heat to 70-75 °C, and maintain the temperature for 1 h.

[0102] Post-processing: The mixture was cooled to 20–25 °C, and lyophilized to obtain 42 mg of a blue-green solid compound C, with a yield of 25% and a purity of 97.65%. MS: [M-4Na+4H+2H] 2+ =721.8.

[0103] Example 4. Synthesis of Compound D

[0104]

[0105] Step 1: D03 Synthesis

[0106]

[0107] Weigh DO1 (500 mg, 1.02 mmol) and DO2 (524 mg, 1.2 mmol), add them to a 25 mL single-necked flask, and dissolve them in DMSO (15 mL). Add HTAU (457 mg, 1.2 mmol) and DIEA (263 mg, 2.04 mmol), stir for 2 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and freeze-dry to obtain white solid DO3 (330 mg, yield 36%).

[0108] Step 2: D04 Synthesis

[0109]

[0110] Weigh DO3 (330 mg, 0.37 mmol) and add it to a 25 mL single-necked flask. Dissolve it in DMSO (20 mL). Add DBU (1,8-Diazabicyclo[5.4.0]undec-7-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene) (330 mg), stir for 1 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and dry to obtain DO4 (250 mg crude product, yield calculated as 100%).

[0111] Step 3: D06 Synthesis

[0112]

[0113] Weigh DO4 (250 mg, 0.37 mmol) and DO5 (105 mg, 0.41 mmol), add them to a 25 mL single-necked flask, and dissolve them in DMSO (15 mL). Add HTAU (168 mg, 0.44 mmol) and DIEA (95 mg, 0.74 mmol), stir for 2 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and freeze-dry to obtain white solid DO6 (176 mg, yield 52%).

[0114] Step 4: D07 Synthesis

[0115]

[0116] Solid D06 (176 mg, 0.19 mmol) was dissolved in DCM (20 mL), TFA (4 mL) was added, and the mixture was stirred at room temperature for 2 h. Saturated sodium carbonate (20 mL) solution was added, and the mixture was separated, dried, and evaporated to dryness to obtain solid compound D07 (132 mg crude product, yield calculated as 100%).

[0117] Step 5: Synthesis of Compound D

[0118]

[0119] Dissolve IR Dye 800 NHS (40 mg, 0.036 mmol) in 10 ml of buffer solution (pH=8.4), and dissolve D07 (23 mg, 0.036 mmol) in 10 ml of buffer solution (pH=8.4). Add the solution to the above solution and react at room temperature for 2 h.

[0120] Post-processing: Preparation, lyophilized to obtain 22 mg of blue-green solid compound D, yield 34%, purity 97.4%, MS: [M-4Na+4H+2H] 2+ =840.87.

[0121] Example 5. Synthesis of Compound E

[0122]

[0123] Step 1: Synthesis of compound E03

[0124]

[0125] Weigh E01 (436 mg, 1.44 mmol) and E02 (500 mg, 1.31 mmol), add them to a 25 mL single-necked flask, and dissolve them in DMSO (15 mL). Add HTAU (600 mg, 1.57 mmol) and DIEA (254 mg, 1.96 mmol), stir for 2 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and freeze-dry to obtain white solid E03 (500 mg, yield 57%).

[0126] Step 2: Synthesis of compound E04

[0127]

[0128] Weigh E03 (500 mg, 0.75 mmol) and add it to a 25 mL single-necked flask. Add DMSO (15 mL) to dissolve it. Add DBU (330 mg) and stir for 1 h. After the reaction is complete, add the reaction solution to MTBE, centrifuge, and dry to obtain E04 (330 mg crude product, yield calculated as 100%).

[0129] Step 3: Synthesis of E06

[0130]

[0131] Weigh E04 (330 mg, 0.74 mmol) and E05 (278 mg, 0.62 mmol), add them to a 25 mL single-necked flask, and dissolve them in DMSO (10 mL). Add HTAU (283 mg, 0.74 mmol) and DIEA (120 mg, 0.93 mmol), stir for 2 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and freeze-dry to obtain white solid E06 (200 mg, yield 35%).

[0132] Step 4: Synthesis of E07

[0133]

[0134] Solid E06 (200 mg, 0.21 mmol) was dissolved in DCM (10 mL), TFA (2.5 mL) was added, and the mixture was stirred at room temperature for 2 h. Saturated Na2CO3 (20 mL) solution was added, and the mixture was separated, dried, and evaporated to dryness to obtain solid compound E07 (130 mg crude product, yield calculated as 100%).

[0135] Step 5: Synthesis of Compound E

[0136]

[0137] Weigh E07 (100 mg, 0.17 mmol) and add it to a 25 ml single-necked flask. Prepare a sodium carbonate aqueous solution (sodium carbonate (100 mg, 0.946 mmol)) and add it to the reaction flask. Add SO456 (165 mg, 0.11 mmol), heat to 70-75 °C, and maintain the temperature for 1 h.

[0138] Post-processing: The mixture was cooled to 20–25 °C, and lyophilized to obtain 50 mg of a blue-green solid compound E, with a yield of 18.7% and a purity of 98.67%. MS: [M-4Na+4H+2H] 2+ =743.3.

[0139] Example 6. Synthesis of Compound F

[0140]

[0141] Step 1: Synthesis of compound F03

[0142]

[0143] Weigh F01 (500 mg, 1.02 mmol) and F02 (475 mg, 1.13 mmol), add them to a 25 mL single-necked flask, and dissolve them in DMSO (15 mL). Add HTAU (466 mg, 1.22 mmol) and DIEA (198 mg, 1.53 mmol), stir for 2 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and freeze-dry to obtain white solid F03 (500 mg, yield 55%).

[0144] Step 2: Synthesis of compound F04

[0145]

[0146] Weigh F03 (500 mg, 0.56 mmol) and add it to a 25 mL single-necked flask. Add DMSO (15 mL) to dissolve it. Add DBU (300 mg) and stir for 1 h. After the reaction is complete, add the reaction solution to MTBE, centrifuge, and dry to obtain F04 (380 mg crude product, yield calculated as 100%).

[0147] Step 3: Synthesis of compound F06

[0148]

[0149] Weigh F04 (380 mg, 0.56 mmol) and F05 (130 mg, 0.51 mmol), add them to a 25 mL single-necked flask, and dissolve them in DMSO (15 mL). Add HTAU (233 mg, 0.61 mmol) and DIEA (99 mg, 0.76 mmol), stir for 2 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and freeze-dry to obtain white solid F06 (150 mg, yield 32%).

[0150] Step 4: Synthesis of compound F07

[0151]

[0152] Solid F06 (150 mg, 0.16 mmol) was dissolved in DCM (20 mL), TFA (4 mL) was added, and the mixture was stirred at room temperature for 2 h. Saturated Na2CO3 (20 mL) solution was added, and the mixture was separated, dried, and evaporated to dryness to obtain solid compound F07 (105 mg crude product, yield calculated as 100%).

[0153] Step 5: Synthesis of compound F

[0154]

[0155] Dissolve IR Dye 800 NHS (34 mg, 0.03 mmol) in 10 ml of buffer solution (pH=8.4), and dissolve F07 (20 mg, 0.03 mmol) in 10 ml of buffer solution (pH=8.4). Add the solution to the above solution and react at room temperature for 2 h.

[0156] Post-processing: Preparation, lyophilized to obtain 15 mg of blue-green solid compound F, yield 29%, purity 98.4%, MS: [M-4Na+4H+2H] 2+ =803.4.

[0157] Example 7. Synthesis of Compound G

[0158]

[0159] Step 1: Synthesis of compound G03

[0160]

[0161] Weigh G01 (500 mg, 1.02 mmol) and G02 (265 mg, 1.23 mmol), add them to a 50 mL single-necked flask, and dissolve them in DMSO (30 mL). Add HTAU (468 mg, 1.23 mmol) and DIEA (263 mg, 2.04 mmol), stir for 2 h, and after the reaction is complete, add the reaction solution to MTBE, centrifuge, and dry to obtain G03 (300 mg, yield 43%).

[0162] Step 2: Synthesis of compound G04

[0163]

[0164] Solid GO3 (300 mg, 0.44 mmol) was dissolved in DCM (20 mL), TFA (4 mL) was added, and the mixture was stirred at room temperature for 2 h. Saturated Na2CO3 (20 mL) solution was added, and the mixture was separated, dried, and evaporated to dryness to obtain solid compound GO4 (190 mg crude product, yield calculated as 100%).

[0165] Step 3: Synthesis of Compound G

[0166]

[0167] IR Dye 800 NHS (66 mg, 0.036 mmol) was dissolved in 10 ml of buffer solution (pH=8.4), and GO4 (25 mg, 0.06 mmol) was dissolved in 10 ml of buffer solution (pH=8.4). The solution was added to the above solution and reacted at room temperature for 2 h.

[0168] Post-processing: Preparation, lyophilized to obtain 18 mg of blue-green solid compound G, yield 20%, purity 97.8%, MS: [M-4Na+4H+2H] 2+ =691.8.

[0169] Example 8. In vivo imaging detection of the compound to confirm efficacy

[0170] 1. In vivo activity imaging of compounds: a prostate cancer model

[0171] A subcutaneous prostate cancer tumor-bearing mouse model of 22Rv1 (ATCC-CRL-2505) was constructed in BALB / c nude mice (athymic nude mice). Human prostate cancer 22Rv1 (ATCC-CRL-2505) cells were cultured in vitro in a monolayer using RPMI 1640 medium supplemented with 10% fetal bovine serum and 1% penicillin / streptomycin / amphoteric B in a 37°C, 5% CO2 incubator. When the cell saturation reached 80%-90% and the desired number was achieved, the cells were harvested, counted, and seeded.

[0172] Put 0.2 mL of 5×10 6 22Rv1 cells (with matrix gel, volume ratio 1:1) were subcutaneously seeded into the nape of the neck of each mouse. The average tumor volume reached 300-400 mm. 3 Grouping and drug administration began at a specific time. Thirty mice with well-developed and regularly shaped tumors were selected for enrollment. These 30 mice were randomly divided into 10 groups of 3 mice each. Groups G1 through G9 contained compounds AG, 8 (OTL78), and 9 (DGPR1008), respectively. Scanning times were 1, 2, 4, 8, and 24 hours. A blank control group of 3 mice was included.

[0173] Mice bearing 22Rv1 tumor xenografts were intravenously injected with 10 nmol / mouse of compounds A-G and 8-9 (5% glucose solution, the same below), while the blank control group was injected with 5% glucose solution (see Table 1 below). Whole-body imaging was then performed using a small animal in vivo imaging system (IVIS Lumina LT serier III), which included a near-infrared fluorescence imaging system. Imaging was performed at 1h, 2h, 4h, 8h, and 24h (the blank control group was imaged at 1h and 24h). The same diameter was used to delineate the tumor and background areas, and fluorescence values ​​were obtained. The tumor-to-background ratio (TBR) was calculated, and the average value was calculated. A higher TBR value tends to provide a clearer tumor boundary, potentially offering a better surgical field of view during surgery. The TBR values ​​are shown in Table 2 below. Specific results are as follows: Figure 1 As shown.

[0174]

[0175] As shown in Table 2, all nine treatment groups provided a certain tumor background ratio at 1 hour and beyond (significantly different from the blank control group). The degree of advantage varied at different time points, as detailed below:

[0176] ① Compound C has obvious advantages: except for 1 hour, the TBR values ​​of compound C are superior to those of other compounds at all other time points;

[0177] ② Between 1 and 24 hours, TBR showed an upward trend, with the peak TBR occurring at 24 hours;

[0178] ③At the 1-hour time point, the TBR values ​​of compounds A to G were all greater than the peak value of OTL78 at 24 hours. From 2 to 24 hours, the TBR values ​​of compounds A to G were all greater than the peak value of OTL78 at 24 hours.

[0179] ④ At each time point, the TBR values ​​of all compounds were > DGPR1008 > OTL78.

[0180] In addition, from Figure 1 It can be seen that compounds A to G each have their own advantages at different time points, and their specific effects are all better than those of the known compounds DGPR1008 and OTL78.

[0181]

[0182] 2. Imaging of Ex vivo Tissues – Tissue Distribution Experiment

[0183] A subcutaneous prostate cancer tumor-bearing mouse model of 22Rv1 (ATCC-CRL-2505) was constructed in BALB / c nude mice (athymic nude mice). Human prostate cancer 22Rv1 (ATCC-CRL-2505) cells were cultured in vitro in a monolayer using RPMI 1640 medium supplemented with 10% fetal bovine serum and 1% penicillin / streptomycin / amphoteric B in a 37°C, 5% CO2 incubator. When the cell saturation reached 80%-90% and the desired number was achieved, the cells were harvested, counted, and seeded.

[0184] Put 0.2 mL of 5×10 6 22Rv1 cells (with matrix gel, volume ratio 1:1) were subcutaneously seeded into the nape of the neck of each mouse. The average tumor volume reached 300-400 mm. 3 Grouping and drug administration began at that time. Thirty mice with good tumor growth and regular shape were selected for the group. The 30 mice were randomly divided into 10 groups of 3 mice each. G1 to G9 included compound AG group, compound 8 (OTL78) and compound 9 (DGPR1008) group, respectively, and a blank control group of 3 mice.

[0185] Mice bearing 22Rv1 tumor xenografts were intravenously injected with 10 nmol / mouse of compounds A-G and compounds 8-9 (5% glucose solution, the same below), while the blank control group was injected with 5% glucose solution (see Table 1). The mice were then euthanized 2 hours later, and organs (tumor, heart, liver, spleen, lung, kidney, stomach, muscle, skin, ovary, pancreas, colon, and small intestine) were collected for in vivo imaging. The tumor-to-prostate ratio was calculated; a higher ratio indicated a greater potential for providing clearer tumor boundaries during surgery. The imaging equipment included a near-infrared fluorescence imaging system. Tumor tissue samples are shown in Table 3 below. Figure 2 As shown.

[0186] The results show that:

[0187] 1) Compounds A~G and 8-9 showed significant advantages compared to the blank control group;

[0188] 2) Order of T / P ratio: Compound A ≈ Compound E > Compound D > Compound C > Compound F > Compound G > Compound B > Compound 9 > Compound 8 > Blank control;

[0189] 3) This experiment selected 2h as the time point for calculating the T / P ratio in ex vivo dissection, which showed a very superior T / P ratio. According to the fact that the peak of TBR in in vivo imaging occurs at 24h, the T / P ratio would be even more advantageous if the dissection time is delayed.

[0190]

[0191] Furthermore, from Figure 2 It can be seen that the compound AG of the present invention has better specific effects than the known compounds DGPR1008 and OTL78.

[0192] In summary, the tumor-targeting imaging compounds of this invention can perform fluorescence imaging on target tumors, thereby determining the distribution of tumor tissue based on the fluorescence imaging, and further diagnosing or determining the disease status or performing surgery. These compounds, obtained through specific design, possess advantages such as good targeting, high affinity for tumor tissue, fast signal response, and high resolution, thus effectively reducing the positive margin rate and false positive rate. Specifically, experiments have shown that the seven compounds currently provided by this invention are expected to specifically bind to tumor cells overexpressing PSMA, such as prostate tumor cells, in vivo, achieving the goal of illuminating the tumor. Due to their superior pharmacokinetic characteristics, their effect in distinguishing tumor tissue from normal tissue is significantly better than that of the known compounds DGPR1008 and OTL78. It is expected that this clinical effect can be demonstrated at doses lower than DGPR1008 and OTL78, with potentially higher safety.

[0193] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0194] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A compound for tumor-targeted imaging, the compound having the general structural formula shown in Formula I below: XYZ type (Ⅰ) in, X represents the target head, which has the following structure or an alkali metal salt thereof (preferably a Na salt). Y represents a connector, which is selected from one of the following structures: Z represents a dye, which is selected from the following structures.

2. The compound for tumor-targeted imaging according to claim 1, characterized in that, The connector is 3. The compound for tumor-targeted imaging according to claim 2, characterized in that, n = 5~10, preferably 5~7.

4. The compound for tumor-targeted imaging according to claim 3, characterized in that, The compounds are compound A, compound B, compound C, compound D, compound E, compound F, and compound G. The structural formula of compound A is shown below: The structure of compound B is shown in the following formula: The structure of compound C is shown in the following formula: The structure of compound D is shown in the following formula: The structure of compound E is shown in the following formula: The structure of compound F is shown in the following formula: The structure of compound G is shown in the following formula:

5. A method for preparing the compound for tumor-targeted imaging according to any one of claims 1 to 4, comprising the following steps: 1) First, a compound 1 consisting of a target X and a linker Y is formed through a reaction; Preferably, compound 1 is obtained by a method comprising the steps of: first synthesizing linker Y, and then reacting the linker with target X; or The compound 1 is obtained by a method comprising the following steps: first, reacting the Y1 substructure of connector Y with the target X to obtain compound 11, which is connected to the target by the Y1 substructure; then reacting compound 11 with the Y2 substructure of connector Y to obtain compound 1 of the target X and connector Y. 2) Compound 1 is then reacted with dye Y to form a compound for tumor-targeted imaging, thus obtaining the desired product; Preferably, compound 1 is any of the following compounds:

6. The method for preparing the compound for tumor-targeted imaging according to claim 5, characterized in that, In step 2), the dye is SO456, IRDye800, or similar substances; Preferably, when the dye is IRDye800 or an analogue, compound 1 reacts with the dye in a buffer solution at pH 7.2–9.0 and room temperature for 1.5–3 hours, preferably at pH 8.4 and room temperature for 2 hours; or When the dye is SO456 or an analogue, the compound 1 and the dye are reacted in a sodium carbonate solution at 70-75°C for 0.5-1.5 h, preferably 1 h.

7. A composition for tumor-targeted imaging, comprising a tumor-targeted imaging compound of any one of claims 1 to 4 or a compound obtained by the method of claim 5 or 6, and an excipient, said excipient preferably a pharmaceutically acceptable carrier, excipient or diluent.

8. A kit for tumor targeting, comprising a compound for tumor targeting imaging according to any one of claims 1 to 4 or a compound obtained by the method of claim 5 or 6.

9. The use of the compound for tumor-targeted imaging according to any one of claims 1 to 4, the compound obtained by the method of claim 5 or 6, the composition of claim 7, or the kit of claim 8 in the preparation of a fluorescent imaging agent.

10. The use of the compound of any one of claims 1 to 4 by targeting PSMA fluorescence imaging, the compound obtained by the method of claim 5 or 6, the composition of claim 7, or the kit of claim 8 in the preparation of a medicament for intraoperative detection of tumors, specifically in the use of a medicament for performing fluorescence imaging to diagnose, determine, or perform surgery, preferably wherein the tumor is a PSMA-expressing disease, such as prostate cancer.

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