A molecular imaging probe labeling precursor targeting the DDR1 receptor, a probe, and a preparation method and application thereof

Abstract

The present invention relates to the technical field of molecular imaging probes, and particularly relates to a molecular imaging probe labeling precursor targeting the DDR1 receptor, a probe thereof, and a preparation method and application thereof. The molecular imaging probe labeling precursor targeting the DDR1 receptor provided by the present invention reacts with a radionuclide to generate a molecular imaging probe targeting the DDR1 receptor, which has a strong receptor binding force with the DDR1 receptor, can accurately locate the DDR1 receptor in vivo, has excellent in vivo targeting performance, and realizes the purpose of tumor molecular imaging through nuclear medicine imaging. Compared with the radioactive tracer [68Ga]Ga-SDUHYX01, the molecular imaging probe [68Ga]Ga-SDUHYX04 optimizes the molecular structure, reduces the lipophilicity, adjusts the metabolic pathway of the molecular imaging probe, thereby making the tumor-to-liver ratio of the molecular imaging probe higher, and also showing excellent imaging effects at 60 minutes.

Description

Technical Field

[0001] The present invention relates to the technical field of molecular imaging probes, and particularly relates to a molecular imaging probe labeling precursor targeting the DDR1 receptor, a probe, a preparation method thereof and an application thereof. Background Art

[0002] Disclosing the information of this background art section is only intended to increase the understanding of the overall background of the present invention, and is not necessarily regarded as an admission or an implication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] Discoidin domain receptor (DDR) is a member of the transmembrane receptor tyrosine kinase (RTK) superfamily. Different from other transmembrane RTKs, DDR has a discoidin motif in its extracellular domain. Typical RTKs use peptide-like growth factors as ligands, but DDR is activated by various types of triple-helix collagens, which are the most abundant components of the extracellular matrix (ECM). Currently, two types of DDR have been identified, namely DDR1 and DDR2. DDR1 is the most characteristic member of the DDR family and has 5 splice variants, namely DDR1a, DDR1b, DDR1c, DDR1d, and DDR1e. DDR1 can bind to all types of collagens and is mainly expressed in epithelial cells of the lung, kidney, colon, and brain. In DDR1 gene knockout mice, it can be observed that DDR1 can have a certain degree of influence on cell formation, differentiation, and proliferation in the mammary gland, vasculature, and kidney. Research shows that DDR1 is very important for the regulation of basic cell processes, such as proliferation, survival, differentiation, adhesion, and matrix remodeling. At the same time, DDR1 is expressed in a variety of tumors, such as lung cancer, breast cancer, colorectal cancer, ovarian cancer, esophageal cancer, head and neck tumors, liver cancer, testicular cancer, etc., and its high expression is closely related to poor tumor prognosis. Given the link between the change in DDR1 function and the development of tumors, DDR1 has become a new target for cancer research. Therefore, developing a new non-invasive DDR1 expression monitoring technology is of great significance for promoting the early detection of tumors and optimizing tumor treatment strategies.

[0004] With the in-depth development and integration of nuclear medicine and molecular biology, medical imaging technology has entered the era of molecular imaging. Among them, positron emission tomography (PET) for functional imaging enables people to truly understand and diagnose diseases at the molecular level, especially highlighting its advantages in the diagnosis and treatment of tumors. By tracing the receptor changes and abnormal cell signal transduction in diseased tissues, the defects in modern diagnostic techniques can be overcome, providing a basis for the early diagnosis, clinical staging, efficacy evaluation of tumors, and evaluating the prognosis.

[0005] However, the results of previous experiments have shown that the hydrophilic-lipophilic balance of drugs can affect the internalization effect of drugs and the choice of metabolic pathways. Higher lipophilicity can lead to a decrease in the drug metabolism rate and an over-reliance on the hepatoenteral metabolic pathway, resulting in a higher background in the imaging results and making it difficult to distinguish tumors from normal tissues. SUMMARY OF THE INVENTION

[0006] To overcome the above problems, the present invention provides a molecular imaging probe labeling precursor targeting the DDR1 receptor, a probe, a preparation method thereof, and an application thereof.

[0007] To achieve the above technical objectives, the present invention adopts the following technical solutions:

[0008] In a first aspect of the present invention, there is provided a molecular imaging probe labeling precursor targeting the DDR1 receptor, the structural formula of which is shown in formula (I):

[0009]

[0010] Formula (I).

[0011] In a second aspect of the present invention, there is provided an intermediate of the molecular imaging probe labeling precursor targeting the DDR1 receptor described in the first aspect, the structural formula of which is shown in formula (II):

[0012]

[0013] Formula (II).

[0014] In a third aspect of the present invention, there is provided a preparation method of the molecular imaging probe labeling precursor targeting the DDR1 receptor described in the first aspect, comprising the following steps:

[0015] (1) Hydrogenating and reducing compound 1 using palladium on carbon, and performing a condensation reaction on the reduction product with 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), 3-(2-pyrazolo[1,5-a]pyrimidin-6-ylethynyl)benzoic acid, and N,N-diisopropylethylamine (DIPEA) to obtain the compound shown in formula (II);

[0016] (2) Removing the Boc and tBu protections from the compound shown in formula (II), and then adding the chelating agent 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-N-hydroxysuccinimide ester (DOTA-NHS) and N,N-diisopropylethylamine (DIPEA) to perform a condensation reaction to obtain the molecular imaging probe labeling precursor targeting the DDR1 receptor;

[0017] Among them, the structural formula of compound 1 is as follows:

[0018] .

[0019] The fourth aspect of the present invention provides a molecular imaging probe targeting the DDR1 receptor, comprising the molecular imaging probe labeling precursor targeting the DDR1 receptor described in the first aspect or the molecular imaging probe labeling precursor targeting the DDR1 receptor prepared by the preparation method described in the third aspect and a radionuclide.

[0020] The fifth aspect of the present invention provides a preparation method for the molecular imaging probe targeting the DDR1 receptor described in the fourth aspect, comprising:

[0021] After mixing and reacting the molecular imaging probe labeling precursor targeting the DDR1 receptor with the radionuclide, the molecular imaging probe targeting the DDR1 receptor is obtained.

[0022] The sixth aspect of the present invention provides the use of the molecular imaging probe targeting the DDR1 receptor described in the fourth aspect or the molecular imaging probe targeting the DDR1 receptor prepared by the preparation method described in the fifth aspect in the preparation of a preparation for detecting the expression level of the DDR1 receptor in tumors.

[0023] The seventh aspect of the present invention provides the use of the molecular imaging probe targeting the DDR1 receptor described in the fourth aspect or the molecular imaging probe targeting the DDR1 receptor prepared by the preparation method described in the fifth aspect in the preparation of a preparation for diagnosing tumors with high expression of the DDR1 receptor.

[0024] The beneficial effects of the present invention are as follows:

[0025] (1) The molecular imaging probe targeting the DDR1 receptor provided by the present invention has a strong receptor binding force with the DDR1 receptor, can accurately locate the DDR1 receptor in vivo, has excellent in vivo targeting performance, and realizes the purpose of tumor molecular imaging through nuclear medicine imaging. At the same time, compared with the radioactive tracer 68 Ga]Ga-SDUHYX01, the molecular imaging probe 68 Ga]Ga-SDUHYX04 provided by the present invention optimizes the molecular structure, reduces the lipophilicity, adjusts the metabolic pathway of the molecular imaging probe 68 Ga]Ga-SDUHYX04, and thus makes the tumor-to-liver ratio of the molecular imaging probe 68 Ga]Ga-SDUHYX04 higher, and can also show excellent imaging effects at 60 minutes.

[0026] (2) The present invention realizes the non-invasive visualization of the molecular expression of the DDR1 receptor. By investigating the tumor imaging effect of the molecular imaging probe through small animal PET / CT, the non-invasive diagnosis of tumors is realized, so it has good clinical application prospects. Description of the Drawings

[0027] The accompanying drawings of the specification, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0028] Figure 1 Synthetic route of the molecular imaging probe precursor SDUHYX04 targeting the DDR1 receptor;

[0029] Figure 2 High-resolution mass spectrum of Compound 1;

[0030] Figure 3 1H NMR spectrum of Compound 1;

[0031] Figure 4 High-resolution mass spectrum of the compound shown in formula (II);

[0032] Figure 5 High-resolution mass spectrum of the molecular imaging probe precursor SDUHYX04 targeting the DDR1 receptor;

[0033] Figure 6 For the molecular imaging probe 68 Radiochromatographic purity detection chart of [68Ga]Ga-SDUHYX04;

[0034] Figure 7 For the molecular imaging probe 68 Results of cellular uptake and internalization experiment of [68Ga]Ga-SDUHYX04;

[0035] Figure 8 For the molecular imaging probe 68 Results of cellular saturation experiment of [68Ga]Ga-SDUHYX04;

[0036] Figure 9 For the molecular imaging probe 68 Blood clearance curve of [68Ga]Ga-SDUHYX04;

[0037] Figure 10 For the radioactive tracer 68 [68Ga]Ga-SDUHYX01 and the molecular imaging probe 68 PET / CT imaging of [68Ga]Ga-SDUHYX04 in tumor-bearing mice;

[0038] Figure 11 For the radioactive tracer 68 [68Ga]Ga-SDUHYX01 and the molecular imaging probe 68 [68Ga]Ga-SDUHYX04 in vivo biodistribution map, where a is the radioactive tracer 68 [68Ga]Ga-SDUHYX01 and the molecular imaging probe68 Bio-distribution map of 68 Ga]Ga-SDUHYX01 and molecular imaging probe 68 Ga]Ga-SDUHYX04 at 30 min in vivo;

[0039] Figure 12 is a radioactive tracer 68 Ga]Ga-SDUHYX01 and molecular imaging probe 68 Autoradiography of 68 Ga]Ga-SDUHYX01, where a is the radioactive tracer 68 Autoradiography of Specific Embodiments

[0040] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0041] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0042] The first typical embodiment of the present invention provides a molecular imaging probe labeling precursor targeting the DDR1 receptor, and its structural formula is shown as formula (I):

[0043]

[0044] Formula (I).

[0045] For the compound shown in formula (I), in addition to the small molecule entity having the above structure, the physiologically acceptable salts of the compound also belong to the technical solutions under the same concept of the first aspect of the present invention and are within the scope of the technical content protected by the present invention application.

[0046] Among them, the physiologically acceptable salts refer to the organic and inorganic salts of the compounds of the present invention. Physiologically acceptable salts are well-known to those skilled in the art in the relevant field. Physiologically acceptable salts include, but are not limited to, inorganic acid salts such as hydrochloride, hydrobromide, phosphate, sulfate, perchlorate, etc., and organic acid salts such as acetate, oxalate, maleate, tartrate, citrate, succinate, malonate, etc., or salts obtained by other methods recorded in the literature such as ion exchange method.

[0047] The second typical embodiment of the present invention provides an intermediate of the precursor for labeling the molecular imaging probe targeting the DDR1 receptor described in the first aspect, and its structural formula is shown in Formula (Ⅱ):

[0048]

[0049] Formula (Ⅱ).

[0050] The third typical embodiment of the present invention provides a preparation method of the precursor for labeling the molecular imaging probe targeting the DDR1 receptor described in the first aspect, including the following steps:

[0051] (1) Hydrogenate and reduce Compound 1 using palladium on carbon, and carry out a condensation reaction on the reduction product with 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), 3-(2-pyrazolo[1,5-a]pyrimidin-6-ylethynyl)benzoic acid, and N,N-diisopropylethylamine (DIPEA) to obtain the compound shown in Formula (Ⅱ);

[0052] (2) Remove the Boc and tBu protections from the compound shown in Formula (Ⅱ), and then add the chelating agent 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-N-hydroxysuccinimide ester (DOTA-NHS) and N,N-diisopropylethylamine (DIPEA) to carry out a condensation reaction to obtain the precursor for labeling the molecular imaging probe targeting the DDR1 receptor;

[0053] Among them, the structural formula of Compound 1 is as follows:

[0054] .

[0055] In one or more embodiments, in step (1), the molar ratio of Compound 1 to 3-(2-pyrazolo[1,5-a]pyrimidin-6-ylethynyl)benzoic acid, 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), and N,N-diisopropylethylamine (DIPEA) is (17~19):(19~21):(16~28):(44~46), preferably 18:20:27:45.

[0056] In one or more embodiments, in step (2), the method for removing Boc and tBu protection from the compound shown in formula (II) includes:

[0057] Dissolve the compound shown in formula (II) in a mixed solution of trifluoroacetic acid and dichloromethane, and concentrate to remove trifluoroacetic acid after the reaction.

[0058] Preferably, in the mixed solution of trifluoroacetic acid and dichloromethane, the volume ratio of trifluoroacetic acid to dichloromethane is 1:(2 - 5), preferably 1:4.

[0059] In one or more embodiments, in step (2), the method for obtaining the precursor for labeling the molecular imaging probe targeting the DDR1 receptor by adding the chelating agent 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-N-hydroxysuccinimide ester (DOTA-NHS) and N,N-diisopropylethylamine (DIPEA) for condensation reaction includes:

[0060] Remove Boc and tBu protection from the compound shown in formula (II) to obtain a deprotected mixture. Add the deprotected mixture and the chelating agent 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-N-hydroxysuccinimide ester to an organic solvent, add N,N-diisopropylethylamine, and react to obtain the precursor for labeling the molecular imaging probe targeting the DDR1 receptor.

[0061] Preferably, the organic solvent is N,N-dimethylformamide (DMF).

[0062] In one or more embodiments, the molar ratio of the compound shown in formula (II) to the chelating agent 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-N-hydroxysuccinimide ester is 1:(0.8 - 1.3), preferably 1:1.

[0063] In one or more embodiments, the molar ratio of the compound shown in formula (II) to N,N-diisopropylethylamine is 1:(8 - 10), preferably 1:9.5.

[0064] The fourth typical embodiment of the present invention provides a molecular imaging probe targeting the DDR1 receptor, including the precursor for labeling the molecular imaging probe targeting the DDR1 receptor described in the first aspect or the precursor for labeling the molecular imaging probe targeting the DDR1 receptor prepared by the preparation method described in the third aspect and a radionuclide.

[0065] In one or more embodiments, the radionuclide is selected from 18 F, 94 Tc, 99m Tc, 90 In, 111 In, 67 Ga, 68 Ga, 86 Y, 90 Y,177 Lu, 151 Tb, 186 Re, 188 Re, 64 Cu, 67 Cu, 55 Co, 57 Co, 43 Sc, 44 Sc, 47 Sc, 225 Ac, 213 Bi, 212 Bi, 212 Pb, 227 Th, 153 Sm, 166 Ho, 152 Gd, 153 Gd, 157 Gd and 166 one of Dy; preferably 68 Ga.

[0066] Further preferably, the structural formula of the molecular imaging probe targeting the DDR1 receptor is as shown in formula (Ⅲ),

[0067]

[0068] Formula (Ⅲ).

[0069] The fifth typical embodiment of the present invention provides a preparation method of the molecular imaging probe targeting the DDR1 receptor described in the fourth aspect, including:

[0070] After mixing and reacting the molecular imaging probe labeling precursor targeting the DDR1 receptor with the radionuclide, the molecular imaging probe targeting the DDR1 receptor is obtained.

[0071] The sixth typical embodiment of the present invention provides the application of the molecular imaging probe targeting the DDR1 receptor described in the fourth aspect or the molecular imaging probe targeting the DDR1 receptor prepared by the preparation method described in the fifth aspect in the preparation of a preparation for detecting the expression level of the DDR1 receptor in tumors.

[0072] The seventh typical embodiment of the present invention provides the application of the molecular imaging probe targeting the DDR1 receptor described in the fourth aspect or the molecular imaging probe targeting the DDR1 receptor prepared by the preparation method described in the fifth aspect in the preparation of a preparation for diagnosing tumors with high expression of the DDR1 receptor.

[0073] The above tumors include any one of lymphoma, multiple myeloma, and solid tumors. For example, lung cancer, liver cancer, pancreatic cancer, gastric cancer, colon cancer, thyroid cancer, and head and neck tumors, etc., but not limited thereto.

[0074] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0075] Example 1

[0076] Figure 1 The synthesis route of the molecular imaging probe precursor targeting the DDR1 receptor in the present invention is shown in reference Figure 1 , and the molecular imaging probe precursor SDUHYX04 targeting the DDR1 receptor was synthesized.

[0077] 1-(Bromomethyl)-3-nitro-5-(trifluoromethyl)benzene (1415 mg, 5 mmol), N6-Boc-L-lysine tert-butyl ester hydrochloride (2541.5 mg, 7.5 mmol) and potassium carbonate (1035 mg, 7.5 mmol) were dissolved in DMF (5 mL), and the reaction was carried out at 25 °C for 12 hours. After filtration, the product was concentrated and purified by column chromatography (SiO2) to obtain compound 1 (2274.75 mg, yield 90%). The high-resolution mass spectrum of compound 1 is shown as Figure 2 , and the 1H NMR spectrum of compound 1 is shown as Figure 3 .

[0078] Compound 1 (2274.75 mg, 4.5 mmol) was dissolved in 5 mL of methanol, Pd / C (loading rate of Pd was 10%, 758 mg) was added, and the reaction was carried out in a hydrogen atmosphere for 16 hours. After filtration, the product and 3-(2-pyrazolo[1,5-a]pyrimidin-6-yl ethynyl)benzoic acid (1385 mg, 5 mmol) were dissolved in 5 mL of DMF, and 2-(7-azabenzotriazol)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU) (2578 mg, 6.75 mmol) and DIPEA (1451 mg, 11.25 mmol) were added, and the reaction was carried out at room temperature overnight to obtain the compound shown in formula (II) (1984.5 mg, yield 60%). The high-resolution mass spectrum of the compound shown in formula (II) is shown as Figure 4 .

[0079] Dissolve the compound shown in formula (II) (44.1 mg, 0.06 mmol) in 2 mL of trifluoroacetic acid (TFA) and dichloromethane (DCM) (volume ratio 1:4), react at room temperature for 30 min, concentrate to remove TFA, dissolve the mixture with DOTA-NHS (30 mg, 0.06 mmol) in 1 mL of DMF, add DIPEA (74.2 mg, 0.57 mmol), react at room temperature for 10 h, purify by HPLC (reverse-phase chromatographic column, 5% acetonitrile containing 0.1% TFA, 95% acetonitrile containing 0.1% TFA, flow rate 3 mL / min), and lyophilize to obtain the precursor SDUHYX04 (30.1 mg, yield 52%) of the molecular imaging probe targeting the DDR1 receptor, which is the compound shown in formula (I). The high-resolution mass spectrum of the precursor SDUHYX04 of the molecular imaging probe targeting the DDR1 receptor is as Figure 5 shown.

[0080] Example 2

[0081] Dissolve the precursor SDUHYX04 (4 nmol) of the molecular imaging probe targeting the DDR1 receptor in 100 μL of NaOAc buffer (concentration 0.1 M, pH 4.6), then add 400 μL of 68 GaCl3 solution (2 mCi), react at 95 °C for 15 min to obtain the molecular imaging probe 68 Ga]Ga-SDUHYX04 targeting the DDR1 receptor.

[0082] For the molecular imaging probe 68 Ga]Ga-SDUHYX04 prepared in this example, perform radiochemical purity detection using analytical HPLC with a radioactive detector. The HPLC results are as Figure 6 shown. It can be seen from Figure 6 that the radiochemical purity of the molecular imaging probe 68 Ga]Ga-SDUHYX04 is greater than 95%.

[0083] Among them, the HPLC mobile phase (A = 0.1% TFA / water, B = 0.1% TFA / acetonitrile), Zorbax 5 μ C18 100 Å (250 × 4.6 mm, 5 μm), and the HPLC elution conditions are shown in Table 1.

[0084] Table 1 HPLC elution conditions

[0085]

[0086] Example 3

[0087] In vitro and in vivo stability studies:

[0088] For in vitro serum stability study, 10 μL of the molecular imaging probe 68 Ga]Ga-SDUHYX04 was added to 190 μL of fetal bovine serum and incubated at 37 °C for 30 or 60 min. After incubation, absolute ethanol was added to the sample, followed by centrifugation and filtration, and then the radiochemical purity was detected.

[0089] For in vivo stability study, healthy NSG female mice were used to evaluate the metabolic stability of the molecular imaging probe 68 Ga]Ga-SDUHYX04 in vivo. Each female mouse was injected with approximately 37 MBq of the molecular imaging probe 68 Ga]Ga-SDUHYX04 via the tail vein. At 60 min after injection, three female mice were sacrificed respectively to collect blood, liver and kidney samples. After treatment, the radiochemical purity was detected to observe the radiochemical purity in different samples.

[0090] The results of in vitro and in vivo stability studies are shown in Table 2.

[0091] Table 2 Results of in vitro and in vivo stability studies

[0092]

[0093] As can be seen from Table 2, the molecular imaging probe 68 Ga]Ga-SDUHYX04 has good in vitro and in vivo stability and can be used for subsequent experimental studies.

[0094] Example 4

[0095] Determination of hydrophilic-lipophilic balance:

[0096] 10 μL of the molecular imaging probe 68 Ga]Ga-SDUHYX04 was diluted to 500 μL with HEPES buffer solution at pH = 7.4, and then 500 μL of n-octanol was added and shaken vigorously. 100 μL of liquid was taken from each of the aqueous phase and the organic phase to measure its radioactivity count. The partition coefficient was calculated by the formula [Log (radioactivity count in the organic phase / radioactivity count in the aqueous phase)]. The log D of the molecular imaging probe 68 Ga]Ga-SDUHYX04 was -2.23 ± 0.08. The experimental results showed that the molecular imaging probe 68 Ga]Ga-SDUHYX04 had high hydrophilicity.

[0097] Example 5

[0098] Cell uptake, internalization and saturation experimental study:

[0099] (1) Cellular uptake and internalization assay: For the cellular uptake and internalization assay, HT-29 cells were seeded in 12-well plates at a density of 5×10 5 cells / well and co-incubated with the molecular imaging probe 68 Figure 7 Ga]Ga-SDUHYX04 (100 nM) at 37 °C for 30, 60, and 90 minutes. To evaluate the specificity of uptake, a blocking experiment was performed using a 1000-fold molar concentration of the DDR1-targeting inhibitor 7rh. After incubation, the cells were washed three times with PBS, treated with 0.05 M glycine buffer (pH = 2.8) for 10 minutes, washed three times with PBS, all the liquid was collected, the cells were lysed using 1 M NaOH solution, and then the radioactivity of the collected liquid and cell suspension was quantified using a gamma counter. The results are shown in Figure 7 , and it can be seen from 68 that the cellular uptake of the molecular imaging probe 68 68 Ga]Ga-SDUHYX04 increased over time and had a high internalization efficiency. In contrast, in the presence of the DDR1-targeting inhibitor 7rh, the uptake of the molecular imaging probe

[0100] Ga]Ga-SDUHYX04 was significantly reduced, indicating that the binding of the molecular imaging probe 68 d Ga]Ga-SDUHYX04 to the DDR1 receptor was specific. 5 (2) Cellular saturation assay: To evaluate the binding affinity of the molecular imaging probe 68 Figure 8 Ga]Ga-SDUHYX04 to the DDR1 receptor, the equilibrium dissociation constant (K Figure 8 ) was determined using the HT-29 cell line. For the cellular saturation assay, HT-29 cells were seeded in 12-well plates at a density of 3×10 68 cells / well and incubated for 1 hour with different concentrations of the molecular imaging probe 68 ​​​​The K value of Ga]Ga-SDUHYX04 is 26.74 ± 0.57 nM. When incubated with the 7rh solution, the binding of the molecular imaging probe d Ga]Ga-SDUHYX04 to the DDR1 receptor was significantly blocked, indicating its specific binding to the DDR1 receptor. 68 Among them, the structural formula of the DDR1-targeted inhibitor 7rh is shown as follows:

[0101]

[0102] .

[0103] Example 6

[0104] Pharmacokinetic property study:

[0105] The molecular imaging probe 68 Ga]Ga-SDUHYX04 (0.2 mL, 7.4 MBq) was injected into 8-week-old female BALB / c mice via the tail vein, and blood samples were collected from the tail vein at 1, 3, 5, 10, 15, 30, 60, 90, and 120 minutes after injection. The samples were weighed and their radioactivity was measured using a gamma counter. The pharmacokinetic curve was characterized using DAS software. The results are as Figure 9 shown. The change in drug concentration obtained by fitting with DAS software reflects the summary of the distribution phase (α phase) and the elimination phase (β phase). In the distribution phase (α phase), the blood drug concentration decreased rapidly after administration, which was the fast elimination stage. The drug concentration in the elimination phase (β phase) decreased proportionally according to the dynamic equilibrium law, which was the slow elimination stage. Through DAS software analysis, the blood clearance curve of the molecular imaging probe 68 Ga]Ga-SDUHYX04 conforms to the two-compartment model, with a distribution-phase half-life (T1 / 2α) of 1.89 ± 0.46 minutes and an elimination-phase half-life (T1 / 2β) of 50.94 ± 1.58 minutes, and the blood metabolism time is moderate.

[0106] Example 7

[0107] Small animal PET / CT imaging:

[0108] Under anesthesia with 2% isoflurane in oxygen, a Mediso NanoScan μ-PET / CT scanner was used to image after injecting the radioactive tracer 68 Ga]Ga-SDUHYX01 or the molecular imaging probe 68 ​PET / CT imaging was performed 30 and 60 minutes after injection of 68 Ga]Ga-SDUHYX01 or the molecular imaging probe 68 Ga]Ga-SDUHYX04 (0.2 mL, 7.4 MBq). HT-29 tumor-bearing mice (with tumors subcutaneously implanted in the shoulder) were randomly divided into an experimental group and a blocking group (n = 3). In the blocking group, the radioactive tracer Figure 10 As shown, compared with the imaging results at 30 minutes, the molecular imaging probe 68 Ga]Ga-SDUHYX04 had better imaging quality at 60 minutes, with a higher tumor-to-background ratio. The radioactive tracer 68 Ga]Ga-SDUHYX01 also showed excellent imaging effects at 60 minutes. However, due to its high lipophilicity and high liver uptake, the tumor imaging effect at 60 minutes was significantly worse than that of the molecular imaging probe 68 Ga]Ga-SDUHYX04. In the blocking group, tumor uptake was significantly reduced, indicating that the radioactive tracer 68 Ga]Ga-SDUHYX01 and the molecular imaging probe 68 Ga]Ga-SDUHYX04 had high specificity for DDR1 receptor uptake.

[0109] Among them, the structural formula of the radioactive tracer 68 Ga]Ga-SDUHYX01 is as follows:

[0110] .

[0111] Example 8

[0112] Biodistribution study:

[0113] In the biodistribution study, radioactive tracer 68 Ga]Ga-SDUHYX01 or the molecular imaging probe 68 Ga]Ga-SDUHYX04 (0.1 mL, 3.7 MBq) was injected into the tail vein of HT-29 tumor-bearing mice (with tumors subcutaneously implanted in the shoulder). The tumor-bearing mice were sacrificed 30 minutes or 60 minutes after injection, and tumors, blood, and a series of major tissues and organs (including the heart, lungs, liver, kidneys, spleen, intestines, bones, and muscles) were collected. The samples of each tissue and organ were weighed, and the radioactivity of each tissue and organ sample was measured using a gamma counter. As Figure 11As shown, the biodistribution results are basically consistent with the PET imaging results. At 30 minutes and 60 minutes, the radioactive tracer 68 Ga]Ga-SDUHYX01 or the molecular imaging probe 68 Ga]Ga-SDUHYX04 both showed high tumor uptake, while the tumor-to-liver ratio of the molecular imaging probe 68 Ga]Ga-SDUHYX04 was significantly higher. Therefore, the molecular imaging probe 68 Ga]Ga-SDUHYX04 has a better tumor-to-background ratio, which is more conducive to its clinical tumor diagnosis.

[0114] Example 10

[0115] Autoradiography:

[0116] For autoradiography, the tissue organs were placed on a phosphor screen and exposed for 10 minutes, and then the screen was analyzed using a Cyclone Plus phosphor imaging system (Amersham TYPHOON, Cytiva, USA). Figure 12 The autoradiography data of the radioactive tracer 68 Ga]Ga-SDUHYX01 and the molecular imaging probe 68 Ga]Ga-SDUHYX04 are shown. The results show that the molecular imaging probe 68 Ga]Ga-SDUHYX04 showed excellent tumor uptake and tumor-to-liver ratio at 60 minutes.

[0117] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A molecular imaging probe labeling precursor targeting the DDR1 receptor, characterized in that, Its structural formula is shown in Formula (I): Formula (I).

2. The intermediate of the molecular imaging probe labeling precursor targeting the DDR1 receptor according to claim 1, characterized in that, Its structural formula is shown in Formula (II): Formula (II).

3. The preparation method of the molecular imaging probe labeling precursor targeting the DDR1 receptor according to claim 1, characterized in that, It includes the following steps: (1) Use palladium-carbon to carry out hydrogenation reduction on Compound 1, and the reduction product undergoes a condensation reaction with 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, 3-(2-pyrazolo[1,5-a]pyrimidin-6-yl ethynyl)benzoic acid, and N,N-diisopropylethylamine to obtain the compound shown in Formula (II); (2) Remove the Boc and tBu protections from the compound shown in Formula (II), and then add the chelating agent cyclen-PEG4-NHS ester and N,N-diisopropylethylamine to carry out a condensation reaction to obtain the precursor for labeling the molecular imaging probe targeting the DDR1 receptor; Among them, the structural formula of Compound 1 is as follows: ； The structural formula of Formula (II) is as follows: Formula (II).

4. The preparation method according to claim 3, characterized in that, In step (1), the molar ratio of Compound 1 to 3-(2-pyrazolo[1,5-a]pyrimidin-6-yl ethynyl)benzoic acid, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethylurea hexafluorophosphate, and N,N-diisopropylethylamine is (17~19):(19~21):(16~28):(44~46); In step (2), the method for removing the Boc and tBu protections from the compound shown in Formula (II) includes: Dissolve the compound shown in Formula (II) in a mixed solution of trifluoroacetic acid and dichloromethane, and after the reaction, concentrate to remove trifluoroacetic acid; In step (2), the method for adding the chelating agent cyclen-PEG4-NHS ester and N,N-diisopropylethylamine to carry out a condensation reaction to obtain the precursor for labeling the molecular imaging probe targeting the DDR1 receptor includes: Remove the Boc and tBu protections from the compound shown in Formula (II) to obtain a deprotected mixture. Add the deprotected mixture and the chelating agent cyclen-PEG4-NHS ester to an organic solvent, add N,N-diisopropylethylamine, and react to obtain the precursor for labeling the molecular imaging probe targeting the DDR1 receptor.

5. A molecular imaging probe targeting the DDR1 receptor, characterized in that, Composed of the precursor for labeling the molecular imaging probe targeting the DDR1 receptor described in Claim 1 or the precursor for labeling the molecular imaging probe targeting the DDR1 receptor prepared by the preparation method described in Claim 3 and a radionuclide; The radioactive nuclide is selected from 111 In, 67 Ga, 68 Ga, 86 Y, 90 Y, 177 Lu, 64 Cu, 67 Cu, 55 Co, 57 Co, 43 Sc, 44 Sc, 47 Sc, 225 Ac, 213 Bi, 212 Bi, 212 Pb, 153 Sm, 166 Ho, 153 Gd, and 157 Gd.

6. The molecular imaging probe targeting the DDR1 receptor according to claim 5, characterized in that, The structural formula of the molecular imaging probe targeting the DDR1 receptor is shown in Formula (III), Formula (III).

7. The preparation method of the molecular imaging probe targeting the DDR1 receptor according to claim 5, characterized in that, It includes: After mixing and reacting the precursor for labeling the molecular imaging probe targeting the DDR1 receptor with the radionuclide, the molecular imaging probe targeting the DDR1 receptor is obtained.

8. Use of the molecular imaging probe targeting the DDR1 receptor described in Claim 5 or the molecular imaging probe targeting the DDR1 receptor prepared by the preparation method described in Claim 7 in the preparation of a preparation for detecting the expression level of the DDR1 receptor in tumors.

9. Use of the molecular imaging probe targeting the DDR1 receptor described in Claim 5 or the molecular imaging probe targeting the DDR1 receptor prepared by the preparation method described in Claim 7 in the preparation of a preparation for diagnosing tumors with high expression of the DDR1 receptor.

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