A ntsr1 antagonist derivative and uses thereof

Abstract

The present application relates to the field of radiopharmaceutical chemistry and clinical nuclear medicine technology, and particularly relates to a neurotensin receptor subtype 1 (NTSR1) antagonist derivative and application thereof. A radioactive preparation obtained by labeling the NTSR1 antagonist derivative with a radionuclide is simple to prepare, has high radiochemical purity, good stability, high uptake in the tumor site of a tumor-bearing mouse and a high target-to-non-target ratio, and has specific binding with NTSR1 in the tumor, and is a novel tumor radioactive drug with promotional application value.

Description

Technical Field

[0001] This invention relates to the fields of radiopharmaceutical chemistry and clinical nuclear medicine, specifically to a neurotensin receptor subtype 1 (NTSR1) antagonist derivative and its applications. Background Technology

[0002] Neurotensin (NT) is an endogenous polypeptide that acts as both a central neurotransmitter and regulator, and a peripheral hormone. It exerts its effects by binding to specific receptors on the cell membrane. There are three subtypes of neurotensin receptors, among which neurotensin receptor subtype 1 (NTSR1) has a high affinity for NT and mediates most of its physiological effects. NTSR1 is highly expressed in various tumors but almost not expressed in normal tissues. NT has also been shown to have various carcinogenic effects, involving tumor growth and metastasis, which are mediated by the binding of NT to NTSR1. Therefore, NTSR1 is considered a biomarker for cancer progression and an important target for tumor detection and treatment.

[0003] Oncology drugs targeting NTSR1 are mainly divided into peptide drugs based on the NT structure and non-peptide drugs based on NTSR1 antagonists. SR142948A is a potent antagonist of NTSR1, exhibiting high affinity and selectivity for NTSR1. However, most reported molecular probes targeting NTSR1 are peptide compounds based on the NT structure. Reports of non-peptide probes based on SR142948A are relatively few, and most are... 68 Ga、 64 Cu-labeled PET drugs. In comparison, 99m SPECT diagnostic technology used with Tc-labeled drugs has the following advantages: the radionuclide can be... 99 Mo / 99m Tc generators are readily available and easy to obtain; the large number of SPECT devices worldwide facilitates their widespread application. 99m The kitting process for Tc-labeled drugs is simple and controllable; SPECT imaging diagnosis is inexpensive and is already covered by medical insurance, which can benefit more patients.

[0004] In order to prepare novel 99m Tc-labeled NTSR1 antagonist derivatives are used for tumor imaging. This patent modifies the structure of the NTSR1 antagonist SR142948A to obtain a ligand containing a hydrazine nicotinamide (HYNIC) group, which, along with synergistic ligands trimethylolglycine and sodium triphenylphosphine trisulfonate (TPPTS), forms a ligand. 99mTc coordination forms stable, highly stable, highly targeted, and well-balanced target-to-non-target ratio tumor molecular probes targeting NTSR1, which are easy to deploy and can be used for early tumor diagnosis, staging, and efficacy evaluation. This will lay a solid foundation for the realization of translational medicine and precision medicine. Summary of the Invention

[0005] This invention provides an NTSR1 antagonist derivative and its application. The derivative has good stability, is easy to prepare, and can be used for tumor diagnosis and treatment after radiolabeling. It exhibits high tumor uptake and a good target / non-target ratio, which has important scientific significance and application prospects in the field of tumor diagnosis and treatment.

[0006] Specifically, the present invention provides the following technical solutions:

[0007] An NTSR1 antagonist derivative, wherein the structural formula is (I):

[0008]

[0009] The present invention also provides a radioactive preparation comprising the above-mentioned NTSR1 antagonist derivative labeled with a radionuclide.

[0010] Preferably, in the above-mentioned radioactive preparation, the radionuclide portion is a metallic radionuclide. Preferably, in the above-mentioned radioactive preparation, the metallic radionuclide is... 99m Tc, 99 Tc, 94m Tc, 94 Tc, 52 Mn, 186 Re or 188 Re.

[0011] Most preferably, in the above-mentioned radioactive preparation, the radionuclide is... 99m Tc, the structural formula of the radioactive agent is (II):

[0012]

[0013] The present invention also provides the application of the above-mentioned radioactive agents in the fields of tumor diagnosis and / or tumor treatment.

[0014] The beneficial effects of this invention are as follows: This invention provides an NTSR1 antagonist derivative and its application. The radioactive preparation obtained by labeling it with a radionuclide has high uptake in tumors and a good tumor / non-target ratio, which is a novel radiopharmaceutical with promotional significance. Detailed Implementation

[0015] This invention provides an NTSR1 antagonist derivative and its application. In a preferred embodiment, this invention provides a derivative with the general structural formula [ 99m Radioactive preparations containing Tc-(HYNIC-NTSR1)(Tricine / TPPTS):

[0016]

[0017] In this structural formula: the nitrogen atom on the hydrazine group in the HYNIC-NTSR1 molecule, the phosphorus atom in the co-ligand TPPTS, and the oxygen and nitrogen atoms in Tricine are... 99m Tc coordination yields [ 99m Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex.

[0018] The preparation steps are as follows:

[0019] a: Synthesis of ligand HYNIC-NTSR1:

[0020] Compound 1 (J.Med.Chem.2024,67(4),3190-3202) and compound 2 (Eur.J.Nucl.Med.Mol.Imaging.2024,51,3322-3333) were added to a reaction flask, dissolved in N,N-dimethylformamide (DMF), and then triethylamine (Et3N) was added. The mixture was stirred at 60°C for 4 h. Part of the triethylamine was removed by vacuum distillation, and HYNIC-NTSR1 was obtained by thin-layer chromatography purification. The specific synthetic route is as follows:

[0021]

[0022] b:[ 99m Preparation of the Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex:

[0023] Weigh appropriate amounts of Tricine, TPPTS, and HYNIC-NTSR1 ligand and dissolve them in physiological saline. Adjust the pH of the solution to 5.0 and add an appropriate amount of freshly rinsed Na+. 99m TcO4 can be obtained by heating in a boiling water bath for 30 minutes. 99m Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex.

[0024] The [prepared by the above method] 99mThe Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex has a radiochemical purity greater than 95%, is hydrophilic, and exhibits good in vitro stability. It shows high uptake and good retention at tumor sites in tumor-bearing mice. Inhibition by injection of NTSR1 inhibitors significantly reduces tumor uptake, indicating that its uptake in tumors is specific to NTSR1. Imaging results show significant concentration at tumor sites, low uptake in non-target tissues, and its uptake in tumors can be significantly inhibited by NTSR1 inhibitors. Therefore, it is a high-performance novel SPECT molecular probe for tumor imaging.

[0025] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they should be performed in accordance with the techniques or conditions described in the literature in the field, or in accordance with the product manual.

[0026] Example 1

[0027] This embodiment provides an NTSR1 antagonist derivative and its application, referred to as […]. 99m Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS), the structural formula is as follows:

[0028]

[0029] In this structural formula: the nitrogen atom on the hydrazine group in the HYNIC-NTSR1 molecule, the phosphorus atom in the co-ligand TPPTS, and the oxygen and nitrogen atoms in Tricine are... 99m Tc coordination yields [ 99m Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex.

[0030] The preparation methods are as follows, but are not limited to the exemplified complexes:

[0031] 1.[ 99m Preparation of Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS

[0032] Synthesis of a.HYNIC-NTSR1

[0033] Synthesis of compound HYNIC-NTSR1. Compound 1 (23.6 mg, 53.6 nmol) and compound 2 (30.0 mg, 44.6 nmol) were weighed into a round-bottom flask, dissolved in 1 mL of DMF, and then Et3N (0.06 mL, 446 nmol) was added. The mixture was reacted at 60 °C for 4 h. After the reaction was completed, some triethylamine was removed by vacuum distillation, and the mixture was purified by thin-layer chromatography [DCM / MeOH = 8 / 1 (v / v)] to obtain ligand HYNIC-NTSR1 (31.5 mg, 70.8%). 1 H NMR (600MHz, METHANOL-D4) δ8.92(t,J=5.6Hz,1H),8.26(d,J=6.4Hz,1H),8.14(s,1H),7. 98(dd,J=15.3,7.6Hz,2H),7.46–7.15(m,8H),6.82(s,1H),6.62–6.53(m,2H),3.67(d,J=9 .2Hz,6H),3.20(q,J=7.3Hz,1H),3.12(s,2H),2.74(s,2H),2.64(d,J=11.4Hz,6H),2.09(s ,1H),2.05(s,1H),1.83–1.72(m,10H),1.32(q,J=6.5Hz,4H),1.10(s,6H); HR-MS(ESI)for C 51 H 58 N8O 10 NaS[M+H] + :found997.3880,calcd 997.3888.

[0034] The synthetic route is as follows:

[0035]

[0036] b.[ 99m Preparation of Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex

[0037] Weigh 1 mg Tricine and 2 mg TPPTS and dissolve them in 0.5 mL of physiological saline. Adjust the pH of the solution to 5.0 with succinate buffer (pH 5.0). Then, add 20 μg of HYNIC-NTSR1 ligand and 0.5 mL of freshly rinsed […]. 99m The [Tc]NaTcO4 (approximately 370 MBq) can be obtained by heating in a boiling water bath for 30 minutes. 99m Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex.

[0038] This invention [ 99m Performance determination of the Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex:

[0039] 1. Identification of coordination compounds

[0040] Identification was performed using thin-layer chromatography (TLC): the stationary phase was Whatman test paper, the developing solvent was acetone / physiological saline (5:1), and the chromatographic results (R) were determined. f )for:[ 99m Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPPTS): 0-0.3; Na 99m TcO4: 0.8-1.0; 99m TcO2·nH2O: 0.8-1.0. The radiochemical purity of the complex, as determined by the above chromatographic analysis, is greater than 95%.

[0041] 2. Determination of the lipid-water partition coefficient of the complex

[0042] Take 0.9 mL of pH 7.4 phosphate buffer (0.025 mol / L) into a 5 mL centrifuge tube, add 1 mL of n-octanol and 0.1 mL of […]. 99m A Tc-(HYNIC-NTSR1)(Tricine / TPPTS) solution was prepared, capped, vortexed, and centrifuged for 5 min (5000 r / min). Then, 3 × 0.1 mL samples were taken from both the organic and aqueous phases, and the radioactivity counts of the two phases were measured. The partition coefficient D (D = radioactivity of organic phase / radioactivity of aqueous phase) was calculated. This process was repeated three times. The measured […] 99m The lipid-water partition coefficient of the Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex is LogD. 7.4 =-2.81±0.10, which is a negative number, indicating that it is a hydrophilic substance.

[0043] 3. Stability determination of complexes

[0044] The radiochemical purity of the complex was determined after incubation in physiological saline at room temperature for 4 hours and in mouse serum at 37°C for 4 hours, respectively. The results showed that... 99m The Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) complex exhibited radiochemical purity greater than 95% after being placed in physiological saline at room temperature and mouse serum at 37°C for 4 hours, indicating good in vitro stability.

[0045] 4. Biodistribution experiment of the complex in tumor-bearing mice

[0046] 0.10 mL was injected via the tail vein into BALB / c Nude model mice bearing HT-29 tumors. 99m Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) labeled solution (approximately 3.7 × 10⁻⁶) 5 Bq), mice were anesthetized with isoflurane gas 1 hour and 4 hours after injection, and then sacrificed. In addition, compound 2 was used to […]. 99m In vivo inhibition experiments were conducted on mice using [Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS], as follows: 0.10 mL of physiological saline containing 500 μg of compound 2 and 0.10 mL of […]. 99m Tc]Tc-(HYNIC-NTSR1)(Tricine / TPPTS) labeled solution (approximately 3.7 × 10⁻⁶) 5 Mice were injected via tail vein with Bq, and one hour later, they were anesthetized with isoflurane gas and then euthanized by decapitation. Relevant tissues and organs, including the heart, liver, lungs, kidneys, spleen, stomach, bones, muscles, small intestine, large intestine, pancreas, tumor, blood, and thyroid gland, were collected, cleaned, weighed, and their radioactivity counts were measured using a γ-counter. The percentage injection dose per gram (%ID / g) for each tissue was calculated. Four mice were used for each time item. The results are shown in Table 1.

[0047] Table 1 [ 99m Biodistribution of Tc-(HYNIC-NTSR1)(Tricine / TPPTS) in HT-29 tumor-bearing Balb / c nude mice (%ID / g)

[0048]

[0049] 5. SPECT imaging of the complex in tumor-bearing mice

[0050] Injected via tail vein into BALB / c Nude model mice bearing HT-29 tumors [ 99m 0.1 mL (approximately 22 MBq) of Tc-(HYNIC-NTSR1)(Tricine / TPPTS) solution was administered, followed by isoflurane gas anesthesia 1 hour later. The inhibition group received 0.10 mL of physiological saline containing 300 μg of compound 2 and 0.10 mL of […]. 99m Tc-(HYNIC-NTSR1)(Tricine / TPPTS) labeled solution (approximately 22 MBq) was administered via tail vein injection, followed by isoflurane gas anesthesia one hour later. Mice were then fixed in a prone position and subjected to SPECT / CT imaging. SPECT imaging results indicated that in the experimental group... 99mTc-(HYNIC-NTSR1)(Tricine / TPPTS) showed significant concentration in tumors, while tumor uptake was significantly reduced in the inhibition group, further indicating that its uptake in tumors has NTSR1 specificity, suggesting that it can serve as a novel SPECT molecular probe with excellent tumor affinity.

[0051] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention involve changing different linking agents, such as amino acids, peptide chains, polyethylene glycol (PEG) chains, fatty acid chains, etc., or utilizing N-tris(hydroxymethyl)methylglycine (Tricine) and ethylenediamine-N,N'-diacetic acid (EDDA), N-tris(hydroxymethyl)methylglycine (Tricine) and sodium diphenylphosphine-3-sulfonate (TPPMS), N-tris(hydroxymethyl)methylglycine (Tricine) and disodium 3,3'-(phenylphosphinediyl)bis(phenyl-1-sulfonic acid) (TPPDS), N-tris(hydroxymethyl)methylglycine (Tricine) and nicotinic acid (NIC), N-tris(hydroxymethyl)methylglycine... Radioactive preparations obtained by radiolabeling coligands such as tricine and isonicotinic acid, N-tris(hydroxymethyl)methylglycine and 3,5-pyridinedicarboxylic acid (PDA), N-tris(hydroxymethyl)methylglycine and 3-pyridinesulfonic acid (PSA), N-tris(hydroxymethyl)methylglycine and glucohepanoate, N-tris(hydroxymethyl)methylglycine and glucosamine, N-tris(hydroxymethyl)methylglycine and mannitol, and N-tris(hydroxymethyl)methylglycine and diphenylphosphine benzoic acid with radioactive nuclides are all within the scope of protection claimed in this invention.

Claims

1. An NTSR1 antagonist derivative, characterized in that, The structural formula of the NTSR1 antagonist derivative is (I):

2. A radioactive preparation, characterized in that, The radioactive preparation comprises the NTSR1 antagonist derivative of claim 1 labeled with a radionuclide.

3. The radioactive agent according to claim 2, characterized in that, The radionuclide is 99m Tc, 99 Tc, 94m Tc, 94 Tc, 52 Mn, 186 Re or 188 Re.

4. The radioactive agent according to claim 3, characterized in that, When the radioactive nuclide is 99m At Tc, the structural formula of the radioactive agent is (II):

5. The use of the radioactive agent according to any one of claims 2-4 in the preparation of radiopharmaceuticals for tumors.

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