Molecular imaging probe labeling precursor and probe for targeting DDR1 receptor, and preparation method and application of molecular imaging probe labeling precursor and probe

Abstract

The invention relates to the technical field of molecular imaging probes, in particular to a molecular imaging probe labeling precursor of a targeted DDR1 receptor, a probe and a preparation method and application of the molecular imaging probe labeling precursor. The molecular imaging probe of the targeted DDR1 receptor, which is generated by reaction of the marker precursor of the molecular imaging probe of the targeted DDR1 receptor and radionuclide, has relatively strong receptor binding force with the DDR1 receptor, can accurately position the DDR1 receptor in vivo, has excellent in-vivo targeting performance, and achieves the purpose of tumor molecular imaging through nuclear medicine imaging. Compared with a radioactive tracer agent [68Ga] Ga-SDUHYX01, the molecular imaging probe [68Ga] Ga-SDUHYX04 has the advantages that the lipophilicity is reduced and the metabolic pathway of the molecular imaging probe is adjusted by optimizing the molecular structure, so that the tumor liver ratio of the molecular imaging probe is higher, and meanwhile, the molecular imaging probe can also show an excellent imaging effect within 60 minutes.

Description

Technical Field

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

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] The discoidin domain receptor (DDR) is a member of the transmembrane receptor tyrosine kinase (RTK) superfamily. Unlike other transmembrane RTKs, DDR has a discoidin motif in the extracellular domain. Typical RTKs use peptide-like growth factors as ligands, but DDR is activated by various types of triple-helical collagens, which are the most abundant components of the extracellular matrix (ECM). Two types of DDR have been identified, namely DDR1 and DDR2. DDR1 is the most characterized member of the DDR family and has five splice variants, namely DDRla, DDRlb, DDRlc, DDRld, and DDRle. DDR1 can bind to all types of collagen and is mainly expressed in epithelial cells of the lung, kidney, colon, and brain. In DDR1 knockout mice, it can be observed that DDR1 can cause some degree of influence on cell formation, differentiation, and proliferation in the mammary gland, vasculature, and kidney. Studies have shown that DDR1 is very important for the regulation of basic cellular processes, such as proliferation, survival, differentiation, adhesion, and matrix remodeling. At the same time, DDR1 is expressed in many tumors, such as lung cancer, breast cancer, colorectal cancer, ovarian cancer, esophageal cancer, head and neck cancer, liver cancer, testicular cancer, etc. Its high expression is closely related to poor tumor prognosis. Given the connection between changes in DDR1 function and tumor development, DDR1 has become a new target for cancer research. Therefore, the development of new non-invasive DDR1 expression monitoring technology is of great significance for promoting 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 is moving towards the era of molecular imaging. Among them, positron emission tomography (PET) functional imaging allows people to truly understand and diagnose diseases at the molecular level, especially in the diagnosis and treatment of tumors. By tracing the changes in receptors of diseased tissues and abnormalities in cell signal transduction, it overcomes the defects of modern diagnostic technology, provides a basis for early diagnosis, clinical staging, and efficacy evaluation of tumors, and evaluates prognosis.

[0005] However, previous experimental results have shown that the hydrophilicity and lipophilicity of drugs will affect the internalization effect of the drug and the choice of metabolic pathway. Higher lipophilicity will lead to a decrease in the drug metabolism rate and excessive reliance on the enterohepatic pathway for metabolism, resulting in a high background in the imaging results and difficulty in distinguishing between tumors and normal tissues. Summary of the invention

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

[0007] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: The first aspect of the present invention provides a molecular imaging probe labeling precursor targeting DDR1 receptor, the structural formula of which is shown in formula (I):

[0008] Formula (I).

[0009] The second aspect of the present invention provides an intermediate of the molecular imaging probe labeling precursor targeting DDR1 receptor described in the first aspect, and its structural formula is shown in formula (II):

[0010] Formula (II).

[0011] The third aspect of the present invention provides a method for preparing the molecular imaging probe labeling precursor targeting the DDR1 receptor as described in the first aspect, comprising the following steps: (1) Compound 1 is subjected to hydrogenation reduction using palladium on carbon, and the reduction product is subjected to condensation reaction with 2-(7-azabenzotriazole)-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 a compound represented by formula (II); (2) removing Boc and tBu protection from the compound represented by formula (II), and then adding chelating agent tetraazacyclododecane tetraacetic acid-succinimidyl ester (DOTA-NHS) and N,N-diisopropylethylamine (DIPEA) for condensation reaction to obtain the molecular imaging probe labeling precursor targeting DDR1 receptor; The structural formula of compound 1 is shown below: .

[0012] The fourth aspect of the present invention provides a molecular imaging probe targeting DDR1 receptor, comprising the molecular imaging probe labeled precursor targeting DDR1 receptor described in the first aspect or the molecular imaging probe labeled precursor targeting DDR1 receptor prepared by the preparation method described in the third aspect and a radioactive nuclide.

[0013] The fifth aspect of the present invention provides a method for preparing the molecular imaging probe targeting the DDR1 receptor according to the fourth aspect, comprising: After the molecular imaging probe labeling precursor targeting the DDR1 receptor is mixed with the radioactive nuclide for reaction, the molecular imaging probe targeting the DDR1 receptor is obtained.

[0014] The sixth aspect of the present invention provides the use of the molecular imaging probe targeting DDR1 receptor described in the fourth aspect or the molecular imaging probe targeting DDR1 receptor prepared by the preparation method described in the fifth aspect in preparing a preparation for detecting the expression level of DDR1 receptor in tumors.

[0015] The seventh aspect of the present invention provides the use of the molecular imaging probe targeting DDR1 receptor described in the fourth aspect or the molecular imaging probe targeting 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 DDR1 receptor.

[0016] The beneficial effects of the present invention are: (1) The molecular imaging probe targeting DDR1 receptor provided by the present invention has a strong receptor binding affinity with DDR1 receptor, can accurately locate DDR1 receptor in vivo, has excellent in vivo targeting performance, and can achieve the purpose of tumor molecular imaging through nuclear medicine imaging. At the same time, compared with radioactive tracers [ 68 Ga]Ga-SDUHYX01, the molecular imaging probe provided by the present invention [ 68 Ga]Ga-SDUHYX04 reduces lipophilicity and adjusts the molecular imaging probe by optimizing the molecular structure. 68 Ga]Ga-SDUHYX04 metabolic pathway, thus making the molecular imaging probe [ 68 Ga]Ga-SDUHYX04 had a higher tumor-to-liver ratio and also showed excellent imaging at 60 minutes.

[0017] (2) The present invention realizes non-invasive visualization of DDR1 receptor molecule expression, examines the tumor imaging effect of molecular imaging probes through small animal PET / CT, and realizes non-invasive diagnosis of tumors, so it has good clinical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0019] Figure 1 A synthetic route for the molecular imaging probe precursor SDUHYX04 targeting the DDR1 receptor; Figure 2 is the high-resolution mass spectrum of compound 1; Figure 3 is the H NMR spectrum of compound 1; Figure 4 is a high-resolution mass spectrum of the compound represented by formula (II); Figure 5 High-resolution mass spectrometry of SDUHYX04, a molecular imaging probe precursor targeting DDR1 receptor; Figure 6 Molecular imaging probes 68 Ga]Ga-SDUHYX04 radiochemical purity test chart; Figure 7 Molecular imaging probes 68 The results of the cellular uptake and internalization experiments of Ga]Ga-SDUHYX04; Figure 8 Molecular imaging probes 68 Ga]Ga-SDUHYX04 cell saturation experimental results; Fig. 9 Molecular imaging probes 68 Blood clearance curve of Ga]Ga-SDUHYX04; Fig.10 For radioactive tracers 68 Ga]Ga-SDUHYX01 and molecular imaging probes [ 68 PET / CT imaging of Ga]Ga-SDUHYX04 in tumor-bearing mice; Fig.11 For radioactive tracers 68 Ga]Ga-SDUHYX01 and molecular imaging probes [ 68 Ga]Ga-SDUHYX04 biodistribution diagram in vivo, where a is the radioactive tracer [ 68 Ga]Ga-SDUHYX01 and molecular imaging probes [ 68 Ga]Ga-SDUHYX04 biodistribution diagram in vivo at 30 min, b is the radioactive tracer [ 68 Ga]Ga-SDUHYX01 and molecular imaging probes [ 68 Biodistribution diagram of Ga]Ga-SDUHYX04 in vivo at 60 min; Fig.12 For radioactive tracers 68 Ga]Ga-SDUHYX01 and molecular imaging probes [ 68 Ga]Ga-SDUHYX04 autoradiography, where a is the radioactive tracer [ 68 Ga]Ga-SDUHYX01 autoradiography, b is the molecular imaging probe [ 68 Autoradiography of Ga]Ga-SDUHYX04. DETAILED DESCRIPTION

[0020] It should be noted that the following detailed descriptions are exemplary and are 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 meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0022] The first typical embodiment of the present invention provides a molecular imaging probe labeling precursor targeting DDR1 receptor, and its structural formula is shown in formula (I):

[0023] Formula (I).

[0024] The compound represented by formula (I), in addition to the small molecule entity having the above structure, the physiologically acceptable salt of the compound also belongs to the technical solution under the same concept as the first aspect of the present invention, and belongs to the technical content of the present invention.

[0025] Among them, physiologically acceptable salts refer to organic salts and inorganic salts of the compounds of the present invention. Physiologically acceptable salts are well known to those skilled in the art. Physiologically acceptable salts include, but are not limited to, inorganic acid salts such as hydrochlorides, hydrobromides, phosphates, sulfates, perchlorates, etc., and organic acid salts such as acetates, oxalates, maleates, tartrates, citrates, succinates, malonates, etc., or salts obtained by other methods described in the literature such as ion exchange methods.

[0026] A second typical embodiment of the present invention provides an intermediate of the molecular imaging probe labeling precursor targeting DDR1 receptor as described in the first aspect, and its structural formula is shown in formula (II):

[0027] Formula (II).

[0028] A third typical embodiment of the present invention provides a method for preparing a molecular imaging probe labeling precursor targeting DDR1 receptor as described in the first aspect, comprising the following steps: (1) Compound 1 is subjected to hydrogenation reduction using palladium on carbon, and the reduction product is subjected to condensation reaction with 2-(7-azabenzotriazole)-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 a compound represented by formula (II); (2) removing Boc and tBu protection from the compound represented by formula (II), and then adding chelating agent tetraazacyclododecane tetraacetic acid-succinimidyl ester (DOTA-NHS) and N,N-diisopropylethylamine (DIPEA) for condensation reaction to obtain the molecular imaging probe labeling precursor targeting DDR1 receptor; The structural formula of compound 1 is as follows: .

[0029] 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-azabenzotriazole)-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.

[0030] In one or more embodiments, in step (2), the method for removing Boc and tBu protection from the compound represented by formula (II) comprises: The compound represented by formula (II) is dissolved in a mixed solution of trifluoroacetic acid and dichloromethane, and after the reaction, the trifluoroacetic acid is removed by concentration.

[0031] 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.

[0032] In one or more embodiments, in step (2), the chelating agent tetraazacyclododecane tetraacetic acid-succinimidyl ester (DOTA-NHS) and N,N-diisopropylethylamine (DIPEA) are added to carry out a condensation reaction to obtain the molecular imaging probe labeling precursor targeting the DDR1 receptor, which comprises: The compound represented by formula (II) is subjected to Boc and tBu deprotection to obtain a deprotected mixture, the deprotected mixture and the chelating agent tetraazacyclododecane tetraacetic acid-succinimide ester are added to an organic solvent, N,N-diisopropylethylamine is added, and the molecular imaging probe labeling precursor targeting the DDR1 receptor is obtained by reaction.

[0033] Preferably, the organic solvent is N,N-dimethylformamide (DMF).

[0034] In one or more embodiments, the molar ratio of the compound represented by formula (II) to the chelating agent tetraazacyclododecane tetraacetic acid-succinimide ester is 1:(0.8-1.3), preferably 1:1.

[0035] In one or more embodiments, the molar ratio of the compound represented by formula (II) to N,N-diisopropylethylamine is 1:(8-10), preferably 1:9.5.

[0036] A fourth typical embodiment of the present invention provides a molecular imaging probe targeting DDR1 receptor, comprising the molecular imaging probe labeled precursor targeting DDR1 receptor described in the first aspect or the molecular imaging probe labeled precursor targeting DDR1 receptor prepared by the preparation method described in the third aspect and a radioactive nuclide.

[0037] 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.

[0038] More preferably, the molecular imaging probe targeting DDR1 receptor has a structural formula as shown in formula (III):

[0039] Formula (III).

[0040] A fifth typical embodiment of the present invention provides a method for preparing the molecular imaging probe targeting the DDR1 receptor according to the fourth aspect, comprising: After the molecular imaging probe labeling precursor targeting the DDR1 receptor is mixed with the radioactive nuclide for reaction, the molecular imaging probe targeting the DDR1 receptor is obtained.

[0041] A sixth typical embodiment of the present invention provides the use of the molecular imaging probe targeting DDR1 receptor described in the fourth aspect or the molecular imaging probe targeting DDR1 receptor prepared by the preparation method described in the fifth aspect in the preparation of a preparation for detecting the expression level of DDR1 receptor in tumors.

[0042] A seventh typical embodiment of the present invention provides the use of the molecular imaging probe targeting DDR1 receptor described in the fourth aspect or the molecular imaging probe targeting DDR1 receptor prepared by the preparation method described in the fifth aspect in the preparation of a preparation for diagnosing tumors with high DDR1 receptor expression.

[0043] The above tumors include any one of lymphoma, multiple myeloma and solid tumors, such as lung cancer, liver cancer, pancreatic cancer, stomach cancer, colon cancer, thyroid cancer and head and neck tumors, but are not limited thereto.

[0044] 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.

[0045] Example 1 Figure 1 For the synthesis route of the molecular imaging probe precursor targeting DDR1 receptor in the present invention, refer to Figure 1 , synthesized the molecular imaging probe precursor SDUHYX04 targeting DDR1 receptor.

[0046] 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), reacted at 25 °C for 12 hours, filtered, 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 in FIG. Figure 2 As shown, the H NMR spectrum of compound 1 is as follows Figure 3 shown.

[0047] Compound 1 (2274.75 mg, 4.5 mmol) was dissolved in 5 mL methanol, Pd / C (Pd loading rate was 10%, 758 mg) was added, and the reaction was carried out under hydrogen atmosphere for 16 hours. After filtration, the product and 3-(2-pyrazolo[1,5-a]pyrimidin-6-ylethynyl)benzoic acid (1385 mg, 5 mmol) were dissolved in 5 mL DMF, and 2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU) (2578 mg, 6.75 mmol) and DIPEA (1451 mg, 11.25 mmol) were added. 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 in FIG. Figure 4 shown.

[0048] The compound represented by formula (II) (44.1 mg, 0.06 mmol) was dissolved in 2 mL trifluoroacetic acid (TFA) and dichloromethane (DCM) (volume ratio 1:4), reacted at room temperature for 30 min, concentrated to remove TFA, and the mixture was dissolved in 1 mL DMF with DOTA-NHS (30 mg, 0.06 mmol), and DIPEA (74.2 mg, 0.57 mmol) was added, reacted at room temperature for 10 h, purified by HPLC (reverse phase column, 5% acetonitrile containing 0.1% TFA, 95% acetonitrile containing 0.1% TFA, flow rate 3 mL / min), and lyophilized to obtain the molecular imaging probe labeled precursor SDUHYX04 targeting DDR1 receptor (30.1 mg, yield 52%), i.e., the compound represented by formula (I). The high-resolution mass spectrum of the molecular imaging probe labeled precursor SDUHYX04 targeting DDR1 receptor is shown in FIG. Figure 5 shown.

[0049] Example 2 The molecular imaging probe precursor SDUHYX04 (4 nmol) targeting the DDR1 receptor was dissolved in 100 μL of NaOAc buffer (concentration: 0.1 M, pH 4.6), and then 400 μL of 68 GaCl3 solution (2 mCi) was reacted at 95 °C for 15 min to obtain a molecular imaging probe targeting DDR1 receptor. 68 Ga]Ga-SDUHYX04.

[0050] The molecular imaging probe prepared in this example [ 68 The radiochemical purity of Ga]Ga-SDUHYX04 was tested by analytical HPLC with a radioactivity detector. The HPLC results are shown in Figure 6 As shown, from Figure 6 As can be seen in the figure, molecular imaging probes[ 68 The radiochemical purity of Ga]Ga-SDUHYX04 is greater than 95%.

[0051] 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.

[0052] Table 1 HPLC elution conditions

[0053] Example 3 In vitro and in vivo stability studies: For in vitro serum stability studies, 10 μL of the molecular imaging probe [ 68 Ga]Ga-SDUHYX04 was added to 190 μL fetal bovine serum and incubated at 37 °C for 30 or 60 min. After incubation, the samples were added with anhydrous ethanol and centrifuged, filtered, and then tested for radiochemical purity.

[0054] For in vivo stability studies, healthy NSG female mice were used to evaluate the molecular imaging probes [ 68 The metabolic stability of Ga]Ga-SDUHYX04 in vivo. Each female mouse was injected with about 37 MBq of molecular imaging probe [ 68 Ga]Ga-SDUHYX04, 60 min after injection, blood, liver, and kidney samples were collected from three female mice, and radiochemical purity was tested after processing to observe the radiochemical purity in different samples.

[0055] The results of in vitro and in vivo stability studies are shown in Table 2.

[0056] Table 2 Results of in vitro and in vivo stability studies

[0057] It can be seen from Table 2 that molecular imaging probes [ 68 Ga]Ga-SDUHYX04 has good stability in vivo and in vitro and can be used for subsequent experimental studies.

[0058] Example 4 Hydrophilicity and lipophilicity determination: 10 μL molecular imaging probe[ 68 Ga]Ga-SDUHYX04 was diluted to 500 μL with HEPES buffer 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 and organic phases to measure their radioactivity counts. The lipid-water partition coefficient was calculated using the formula [Log (radioactivity counts in the organic phase / radioactivity counts in the aqueous phase)], and the molecular imaging probe [ 68 The log D of Ga]Ga-SDUHYX04 is -2.23±0.08, and the experimental results show that the molecular imaging probe [ 68 Ga]Ga-SDUHYX04 has high hydrophilicity.

[0059] Example 5 Cellular uptake, internalization and saturation experimental studies: (1) Cell uptake and internalization experiment: For the cell uptake and internalization experiment, HT-29 cells were cultured at 5×10 5 Cells were seeded at a density of 1.54 × 10 cells / well in 12-well plates and incubated at 37 °C with molecular imaging probes [ 68 Ga]Ga-SDUHYX04 (100 nM) was co-incubated 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-targeted inhibitor 7rh. After incubation, the cells were washed three times with PBS, incubated with 0.05 M glycine buffer (PH=2.8) for 10 minutes, washed three times with PBS, all the fluid was collected, lysed with 1 M NaOH solution, and the radioactivity of the collected fluid and cell suspension was quantified using a γ counter. The results are shown in Figure 7 As shown, from Figure 7 It can be seen that molecular imaging probes [ 68 The cellular uptake of Ga]Ga-SDUHYX04 increased over time and had a high internalization efficiency. In contrast, in the presence of the DDR1-targeting inhibitor 7rh, the molecular imaging probe [ 68 Ga]Ga-SDUHYX04 uptake was significantly reduced, indicating that the molecular imaging probe [ 68 Ga]Ga-SDUHYX04 binds specifically to the DDR1 receptor.

[0060] (2) Cell saturation experiment: to evaluate molecular imaging probes 68 The binding affinity of Ga]Ga-SDUHYX04 to DDR1 receptor was determined using HT-29 cell line, and the equilibrium dissociation constant (K d For cell saturation experiments, HT-29 cells were plated at 3 × 10 5 Cells were seeded at a density of 1 / well in 12-well plates and incubated with different concentrations of molecular imaging probes [ 68 Ga]Ga-SDUHYX04 (0.78125 nM, 1.5625 nM, 3.125 nM, 6.25 nM, 12.5 nM, 25 nM, 50 nM, and 100 nM) was incubated for 1 h. In parallel, nonspecific binding was assessed by co-incubating cells with 1000-fold molar concentrations of the DDR1-targeted inhibitor 7rh over the same concentration range. After incubation, the radioactivity of the cell suspension was measured using a gamma counter, and the data were analyzed by nonlinear regression using GraphPadPrism 5.0 to determine the Kd value. The results are shown in Figure 8 As shown, from Figure 8 As can be seen in the figure, molecular imaging probes[ 68 Ga]Ga-SDUHYX04 has a high binding affinity with DDR1 receptors and is a molecular imaging probe [ 68 Ga]Ga-SDUHYX04 K d The value was 26.74±0.57 nM. When incubated with 7rh solution, the molecular imaging probe [ 68 The binding of Ga]Ga-SDUHYX04 to DDR1 receptor was significantly blocked, indicating that its binding to DDR1 receptor is specific.

[0061] Among them, the structural formula of DDR1 targeted inhibitor 7rh is as follows: .

[0062] Example 6 Pharmacokinetic properties studies: Eight-week-old female BALB / c mice were injected with molecular imaging probes via the tail vein. 68 Ga]Ga-SDUHYX04 (0.2 mL, 7.4 MBq), and blood samples were collected from the tail vein at 1, 3, 5, 10, 15, 30, 60, 90, and 120 min after injection. The samples were weighed and their radioactivity was measured using a γ counter. The pharmacokinetic curves were characterized using DAS software. The results are shown in Fig. 9As shown. The drug concentration changes obtained by DAS software fitting reflect the summary of the distribution phase (α phase) and the elimination phase (β phase). The blood drug concentration in the distribution phase (α phase) drops rapidly after administration, which is the fast elimination phase. The drug concentration in the elimination phase (β phase) decreases proportionally according to the dynamic equilibrium law, which is the slow elimination phase. The molecular imaging probe [ 68 The blood clearance curve of Ga]Ga-SDUHYX04 conformed to the two-compartment model, with the distribution phase half-life (T1 / 2α) of 1.89±0.46 minutes and the elimination phase half-life (T1 / 2β) of 50.94±1.58 minutes, indicating a moderate blood metabolism time.

[0063] Example 7 Small Animal PET / CT Imaging: Under anesthesia with 2% isoflurane in oxygen, a Mediso NanoScan μ-PET / CT scanner was used after injection of radiotracer [ 68 Ga]Ga-SDUHYX01 or molecular imaging probe [ 68 PET / CT imaging was performed 30 and 60 minutes after the administration of Ga]Ga-SDUHYX04 (0.2 mL, 7.4 MBq). HT-29 tumor-bearing mice (shoulder subcutaneous tumor) were randomly divided into an experimental group and a blocking group (n = 3). In the blocking group, mice were simultaneously injected with radioactive tracer [ 68 Ga]Ga-SDUHYX01 or molecular imaging probe [ 68 Ga]Ga-SDUHYX04 and 7rh (20 mg / kg). PET / CT images were reconstructed using Nucline NanoScan 3.0 software and subsequently analyzed using InterView FUSION 3.0 software. Fig.10 As shown, compared with the 30-minute imaging results, the molecular imaging probe [ 68 Ga]Ga-SDUHYX04 has excellent imaging quality at 60 minutes, with a high tumor-to-background ratio. 68 Ga]Ga-SDUHYX01 also showed excellent imaging effect at 60 min, but due to its high lipophilicity and high liver uptake, the tumor imaging effect at 60 min was significantly worse than that of the molecular imaging probe [ 68 Ga]Ga-SDUHYX04. However, tumor uptake was significantly reduced in the blocking group, suggesting that the radiotracer [ 68 Ga]Ga-SDUHYX01, molecular imaging probe [ 68 Ga]Ga-SDUHYX04 is highly specific for DDR1 receptor uptake.

[0064] Among them, radioactive tracers [68 The structural formula of Ga]Ga-SDUHYX01 is shown below: .

[0065] Example 8 Biodistribution studies: In the biodistribution study, HT-29 tumor-bearing mice (subcutaneous tumors in the shoulder) were injected with radiotracer via the tail vein. 68 Ga]Ga-SDUHYX01 or molecular imaging probe [ 68 Ga]Ga-SDUHYX04 (0.1 mL, 3.7 MBq). Tumor-bearing mice were killed 30 minutes or 60 minutes after injection, and tumors, blood, and a series of major tissues and organs (including heart, lung, liver, kidney, spleen, intestine, bone, and muscle) were collected. Each tissue and organ sample was weighed, and the radioactivity of each tissue and organ sample was measured using a γ counter. Fig.11 As shown, the biodistribution results were consistent with the PET imaging results. At 30 and 60 minutes, the radiotracer [ 68 Ga]Ga-SDUHYX01 or molecular imaging probe [ 68 Ga]Ga-SDUHYX04 showed high tumor uptake, while the molecular imaging probe [ 68 The tumor-liver ratio of Ga]Ga-SDUHYX04 was significantly higher. 68 Ga]Ga-SDUHYX04 has a better tumor-to-background ratio, which is more conducive to its clinical tumor diagnosis.

[0066] Example 10 Autoradiography: For autoradiography, tissue organs were placed on a phosphor screen and exposed for 10 min, and the screen was subsequently analyzed using a Cyclone Plus phosphorimaging system (Amersham TYPHOON, Cytiva, USA). Fig.12 Radioactive tracers were demonstrated [ 68 Ga]Ga-SDUHYX01 and molecular imaging probes [ 68 The results show that the molecular imaging probe [ 68 Ga]Ga-SDUHYX04 showed excellent tumor uptake and tumor-to-liver ratio at 60 min.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

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

3. The method for preparing a molecular imaging probe labeling precursor targeting DDR1 receptor according to claim 1, characterized in that: The steps include: (1) Compound 1 is subjected to hydrogenation reduction using palladium on carbon, and the reduction product is subjected to condensation reaction with 2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate, 3-(2-pyrazolo[1,5-a]pyrimidin-6-ylethynyl)benzoic acid and N,N-diisopropylethylamine to obtain a compound represented by formula (II); (2) removing Boc and tBu protection from the compound represented by formula (II), and then adding chelating agent tetraazacyclododecane tetraacetic acid-succinimidyl ester and N,N-diisopropylethylamine for condensation reaction to obtain the molecular imaging probe labeling precursor targeting DDR1 receptor; The structural formula of compound 1 is shown below: 。 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-ylethynyl)benzoic acid, 2-(7-azabenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate and N,N-diisopropylethylamine is (17-19):(19-21):(16-28):(44-46); In step (2), the method for removing Boc and tBu protection from the compound represented by formula (II) comprises: The compound represented by formula (II) is dissolved in a mixed solution of trifluoroacetic acid and dichloromethane, and after the reaction, the solution is concentrated to remove the trifluoroacetic acid; In step (2), a chelating agent tetraazacyclododecane tetraacetic acid-succinimide ester and N,N-diisopropylethylamine are added to carry out a condensation reaction to obtain the molecular imaging probe labeling precursor targeting the DDR1 receptor, comprising: The compound represented by formula (II) is subjected to Boc and tBu deprotection to obtain a deprotected mixture, the deprotected mixture and the chelating agent tetraazacyclododecane tetraacetic acid-succinimide ester are added to an organic solvent, N,N-diisopropylethylamine is added, and the molecular imaging probe labeling precursor targeting the DDR1 receptor is obtained by reaction.

5. A molecular imaging probe targeting DDR1 receptor, characterized in that: It comprises the molecular imaging probe labeling precursor targeting DDR1 receptor as described in claim 1 or the molecular imaging probe labeling precursor targeting DDR1 receptor prepared by the preparation method as described in claim 3 and a radioactive nuclide.

6. The molecular imaging probe targeting DDR1 receptor according to claim 5, characterized in that: 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.

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

8. The method for preparing a molecular imaging probe targeting DDR1 receptor according to claim 5, characterized in that: include: After the molecular imaging probe labeling precursor targeting the DDR1 receptor is mixed with the radioactive nuclide for reaction, the molecular imaging probe targeting the DDR1 receptor is obtained.

9. Use of the molecular imaging probe targeting DDR1 receptor according to claim 5 or the molecular imaging probe targeting DDR1 receptor prepared by the preparation method according to claim 8 in preparing a preparation for detecting the expression level of DDR1 receptor in tumors.

10. Use of the molecular imaging probe targeting DDR1 receptor according to claim 5 or the molecular imaging probe targeting DDR1 receptor prepared by the preparation method according to claim 8 in preparing a preparation for diagnosing tumors with high expression of DDR1 receptor.

Images