A 18 F-MFPBG automated marking method and uses

Abstract

The application discloses a kind of 18 F-MFPBG automatic marking method and purpose, it relates to the field of radiopharmaceutical chemistry, the marking method is sequentially executed by automatic synthesis system 18 F ion enrichment elution, nucleophilic substitution reaction with precursor MFPBG, preliminary purification, acid hydrolysis, preparative high performance liquid chromatography separation and purification and final sterile injection preparation etc. Step, realizes the automation and standardization of marking process. The application also provides 18 The use of F-MFPBG for preparing myocardial sympathetic nerve imaging agent, which is suitable for the diagnosis, prognosis evaluation or treatment effect monitoring of coronary heart disease, arrhythmia or heart failure. The imaging agent prepared by the method of the application has the advantages of suitable half-life, high labeling efficiency and stable product quality, providing a reliable tool for in vivo quantitative evaluation of cardiac sympathetic nerve function.

Description

Technical Field

[0001] This invention relates to the field of radiopharmaceutical chemistry, and more particularly to a myocardial function compound and isotope labeling, specifically a... 18 F-MFPBG automated labeling method and its applications. Background Technology

[0002] The cardiac autonomic nervous system consists of the sympathetic and parasympathetic nervous systems, which work together to regulate the heart's rhythmic conduction and contractile function through antagonistic and coordinated physiological activities. During the development of coronary artery disease (CAD), myocardial ischemia or infarction can trigger cardiac autonomic remodeling, manifested as excessive sympathetic activation and vagal nerve dysfunction. This neural remodeling is a significant initiating factor for ventricular arrhythmias and heart failure. Therefore, qualitative and even quantitative assessments of cardiac autonomic function at different stages of CAD are of crucial clinical value for early diagnosis, risk stratification, treatment decisions, and prognosis.

[0003] However, changes in the cardiac autonomic nervous system are at the molecular and functional level and cannot be directly observed through conventional morphological examinations or cardiac function tests. Currently, radionuclide molecular imaging is the only technique capable of visually assessing the cardiac sympathetic nervous system in vivo. Existing radiopharmaceuticals used for cardiac sympathetic nerve imaging fall into two main categories. One category is iodine-123-labeled m-iodobenzylguanidine, an analogue of norepinephrine, which indirectly reflects the functional state of the sympathetic nervous system through uptake and storage at sympathetic nerve endings. Related clinical studies have confirmed its value in assessing the severity and prognosis of myocardial ischemia. The other category is imaging agents based on positron emission tomography (PET), such as... 11 C-labeled norepinephrine and other norepinephrine analogs are positron-emitting drugs that can more accurately quantify the uptake, metabolism and storage of catecholamines.

[0004] However, the aforementioned existing technologies all have significant limitations. Iodine-123-labeled m-iodobenzylguanidine, due to its long physical half-life, often faces the problem of untimely drug supply. Furthermore, the limited spatial resolution of single-photon emission computed tomography (SPECT) instruments results in poor image quality and makes accurate quantitative analysis difficult. 11 Although C-labeled compounds offer high imaging precision, their extremely short physical half-life of only about twenty minutes means that the imaging agents must be used within a very short time after preparation. This prevents them from being used for long-term dynamic imaging or transported to medical institutions far from the production center, which greatly limits their clinical application.

[0005] Therefore, there is an urgent need in this field for a novel cardiac sympathetic nerve positron emission tomography agent that combines a suitable half-life, high imaging quality, and a stable automated preparation process. Summary of the Invention

[0006] This invention overcomes the shortcomings of the prior art and provides a 18 The F-MFPBG automated labeling method and its applications provide new, specific compounds for myocardial tissue and broad-spectrum myocardial imaging agents in nuclear medicine. In particular, the compounds described in this invention were previously unknown or not suggested, and the new compounds have better tissue specificity, targeting, and pharmacokinetic properties.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a compound targeting the cardiac sympathetic nerve, having the structure shown in formula (I):

[0008] .

[0009] The present invention also provides a corresponding radioactive preparation comprising MFPBG labeled with a radionuclide.

[0010] Preferably, in the above-mentioned radioactive agents, the radionuclide is... 18 F.

[0011] Preferred, 18 F-labeled radioactive agents 18 The F-MFPBG structure is (Ⅱ). This complex has high chemical purity, and all the chemical reagents used are commercially available. It provides clear myocardial imaging and has a long retention time.

[0012]

[0013] This invention addresses the shortcomings of the prior art and has the following beneficial effects:

[0014] (1) The present invention provides 18 F-MFPBG automated marking method and its applications, through the adoption of 18 F is used to label benzylguanidine compounds with specific structural modifications. 18 The introduction of F replaced the problem of excessively short half-life. 11 C or iodine-123, with their moderate physical half-life, provide a more reasonable metabolic kinetic window for the compounds in vivo, thus solving the problem that existing positron emission tomography (PET) agents, due to their short half-life, cannot be used for long-term dynamic observation or long-distance delivery. Compared to... 11 The C-labeled compound, the imaging agent provided by this invention, ensures excellent imaging quality while possessing logistical and operational feasibility for clinical application, thus laying the foundation for quantitative assessment of cardiac sympathetic nerve function in a wider range of medical scenarios.

[0015] (2) This invention establishes a complete and repeatable automated radiolabeling and purification preparation process. This process ensures the high efficiency of the labeling reaction and the high chemical purity of the final product by precisely controlling the conditions and parameters of nucleophilic substitution, acid hydrolysis and chromatographic purification. This enables the automated production of imaging agents with high consistency and stable yield. This method significantly improves the standardization and reliability of the production process, thereby ensuring a stable supply of imaging agents to meet the needs of routine clinical examinations.

[0016] (3) The present invention provides 18 The F-labeled compound exhibits high affinity and specific retention for myocardial sympathetic nerve tissue in vivo. It can be more effectively taken up by sympathetic nerve endings and retained in synaptic vesicles, resulting in highly targeted uptake images of the myocardium in in vivo imaging. Furthermore, it clears background quickly, thereby achieving clear visualization of the distribution and function of cardiac sympathetic nerves. Compared to some imaging agents in the prior art, which may have high non-specific uptake or unsatisfactory retention time, the imaging agent provided by this invention can improve image contrast and diagnostic information quality. This makes it possible to conduct earlier and more accurate qualitative and even quantitative assessments of sympathetic nerve remodeling associated with diseases such as coronary heart disease and arrhythmia, thus providing more reliable molecular imaging evidence for treatment decisions and prognostic judgments. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the automated preparation of the radiolabeled precursor in Example 1 of the present invention;

[0019] Figure 2 This is Embodiment 1 of the present invention. 18 F-MFPBG chromatogram;

[0020] Figure 3 This is Embodiment 1 of the present invention. 18 Imaging of F-MFPBG in rat myocardium;

[0021] Figure 4 This is an image of 18F-MFPBG in the myocardium of Bama pigs according to Embodiment 1 of the present invention. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0024] Automated preparation process of radiolabeled precursors, such as Figure 1 As shown.

[0025] Example 1:

[0026] The preparation methods for S1 and the precursor MFPBG are as follows:

[0027]

[0028] MFPBG is produced from ethylene glycol. It first undergoes nucleophilic substitution with 1,3-dibromopropane to obtain intermediate 1, then reacts with 3-bromo-4-hydroxybenzaldehyde under alkaline conditions to generate intermediate 2, which then reacts with MsCl to obtain intermediate 3. Intermediate 3 is reduced to obtain intermediate 4, which then undergoes photoelectrophoresis with 1,3-di(tert-butoxycarbonyl)guanidine to obtain intermediate 5. The Boc protecting group on intermediate 5 gives the precursor MFPBG.

[0029] S2, such as Figure 1 As shown, 18 The preparation method of F-MFPBG is as follows:

[0030]

[0031] In an automated synthesis system, the following automated labeling and purification procedures are performed:

[0032] a. System self-test and reagent loading: After self-test completion, install the synthesis ferrule and perform a ferrule self-test, and follow the instructions. Figure 1 The reagents are installed as shown:

[0033] (A) 1 mL eluent (composed of K2CO3: 3.94 mg; K 2.2.2 (Mixed with 13.5 mg of methanol, 0.72 mL of methanol, and 0.18 mL of hydrogen hydrate).

[0034] (B) 10 mL of ethanol;

[0035] (C) 1.0 mL DMSO (containing 3.0 mg of precursor MFPBG);

[0036] (D) 2.0 mL Na2CO3 aqueous solution (1 M);

[0037] (E) 2.0 mL HCl aqueous solution (2 M);

[0038] (F) 500 mL of water for injection;

[0039] (G) 60 mL product collection bottle;

[0040] (H) 20 mL ethanol;

[0041] (I) 15 mL of physiological saline (containing 75 mg of sodium ascorbate).

[0042] b. Receive 18 F ions, QMA enrichment 18 F, 1 mL of eluent was used to elute QMA. 18 F enters the reaction flask, and the solvent is evaporated to dryness.

[0043] c. The precursor solution is injected into the reaction flask, and the reaction is carried out under sealed conditions at 120 °C for 15 min to carry out the nucleophilic substitution reaction.

[0044] d. After the reaction is complete, cool the reaction solution to 65 °C, dilute the reaction solution with 7 ml of water, pass the liquid through a Sep-Pak C18 column, wash the C18 column with 10 mL of water, dry the C18 column, rinse the C18 column with 2 mL of ethanol, and enter the reaction flask.

[0045] e. Add 2 mL of hydrochloric acid (2 M) and hydrolyze at 110 °C for 8 min.

[0046] f. After the reaction is complete, cool the reaction solution to 45 °C, add 2 mL of sodium carbonate solution (1 M) to neutralize, extract the neutralized reaction solution, inject it into the injection loop, and execute the preparation procedure:

[0047] Preparative chromatographic conditions: Preparative column: XBridge BEH C18 OBD Pre Column; Flow rate: 5 mL / min.

[0048] Mobile phase: Phase A: acetonitrile-ammonium acetate solution, volume ratio 30:70 (500 mL of mobile phase contains 414 mg of ammonium acetate and 1350 mg of sodium ascorbate) (sonicated for 10 min); Phase B: 200 mL of ethanol; Phase C: 400 mL of water.

[0049] When the collection line is at the peak position, peak collection begins, and peak collection ends when it is at the tail position; the product retention time is 15.5 minutes, and the product peak is collected in the collection bottle.

[0050] g. The collected solution was diluted with 30 mL of water for injection. The diluted solution was transferred to a waste bottle via a Sep-Pak C18 column. The Sep-Pak C18 column was rinsed with 20 mL of water and dried. The C18 column was rinsed with 1.0 mL of ethanol and transferred to a product transfer bottle. The product solution was then diluted with 10 mL of physiological saline (containing 50 mg of sodium ascorbate) to obtain the product solution. The product solution was transferred to a product bottle through a sterile overnight filter membrane to obtain the sterile injection solution.

[0051] The analytical chromatographic conditions are shown in Table 1: Mobile phase A: water (20 mmol / L ammonium acetate, pH adjusted to 4.5 with acetic acid); Mobile phase B: acetonitrile.

[0052] Table 1:

[0053]

[0054] Chromatographic results as follows Figure 2 As shown.

[0055] Experimental Example 1:

[0056] Micro-PET / CT imaging test: Two SD rats, one male and one female, were induced anesthetized and fixed on a bed board. Simultaneously, 2% isoflurane was administered for maintenance anesthesia. Then, the rats were injected via tail vein with the solution prepared in Example 1. 18 F-FMPBG (0.2 mL, 200 μC) was injected, and dynamic image acquisition was performed for 30 min (5 min / f) after the injection, followed by static image acquisition at 2 h. Image reconstruction was performed using the 3D-OSEM+MAP algorithm. Image analysis was performed using Inveon Research Workplace 4.2 software. CT image scanning: tube voltage 80 kV, tube current 500 uA, exposure time 200 ms, preprocessing with a slice thickness of 113.67 μm, reconstruction using the Feldkamp filtered back projection algorithm, and beam hardening correction and ring artifact correction were performed. The results are as follows. Figure 3 As shown.

[0057] Experimental Example 2:

[0058] Micro-PET / CT imaging test: Four Bama pigs, two males and two females, were anesthetized with intramuscular injection of salbutamol and fixed on a bed board. Isoflurane was administered to maintain anesthesia. The pigs were then injected intravenously with the preparation prepared in Example 1. 18F-FMPBG (2 mL, 0.15 mci / kg) was injected, and static image acquisition was performed at 10 min, 20 min, 30 min, and 60 min after the injection. Image analysis was performed using Inveon Research Workplace 4.2 software. CT image scanning: tube voltage 120 kV, tube current 250 mA, preprocessing with a slice thickness of 3.75 mm, and beam hardening correction and ring artifact correction were performed. The results are as follows. Figure 4 As shown.

[0059] The results showed that 18 F-FMPBG exhibits targeted uptake in the myocardium of rats and Bama pigs, with a relatively long retention time.

[0060] The above description is based on the preferred embodiments of the present invention. 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 exemplary and non-limiting in all respects. The scope of the invention is defined by the appended claims rather than the foregoing description, and 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.

[0061] 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 kind 18 The F-MFPBG automated labeling method is characterized by... Includes the following steps: S1. Provide a precursor MFPBG, wherein the MFPBG has the structure shown in Formula I: ； S2. In the automated synthesis system, execute the following automated labeling and purification procedures: a. System self-test and reagent loading; b. Receive 18 F ions were then enriched and eluted. c. After washing 18 F ions undergo a nucleophilic substitution reaction with the precursor MFPBG in an organic solvent; d. The reaction solution is diluted and preliminarily purified using a solid-phase extraction column; e. Perform acid hydrolysis on the pre-purified product; f. After neutralizing the hydrolysis reaction solution, preparative high performance liquid chromatography was used for separation and purification, and the target product peak was collected; g. The collected solution was diluted and then desalted and concentrated again using a solid-phase extraction column, followed by elution with ethanol and physiological saline containing a stabilizer to obtain... 18 F-MFPBG sterile injection solution.

2. The one according to claim 1 18 The F-MFPBG automated labeling method is characterized by: In step c, the conditions for the nucleophilic substitution reaction are: reaction temperature 100-130 °C and reaction time 10-20 min.

3. The one according to claim 2 18 The F-MFPBG automated labeling method is characterized by: The nucleophilic substitution reaction was carried out at 120 °C for 15 min.

4. The one according to claim 1 18 The F-MFPBG automated labeling method is characterized by: In step c, the organic solvent is dimethyl sulfoxide.

5. The method according to claim 1 18 The F-MFPBG automated labeling method is characterized by: In step e, the acid hydrolysis reaction is performed under the following conditions: using 1-3 M hydrochloric acid and reacting at 100-120 °C for 5-10 min.

6. The method according to claim 5 18 The F-MFPBG automated labeling method is characterized by: The acid hydrolysis reaction was carried out using 2 M hydrochloric acid at 110 °C for 8 min.

7. The one according to claim 1 18 The F-MFPBG automated labeling method is characterized by: In step f, the separation conditions for the preparative high-performance liquid chromatography are as follows: Chromatographic column: C18 preparative column; Mobile phase: a mixed solution of acetonitrile and ammonium acetate aqueous solution, wherein the volume ratio of acetonitrile is 25-35%, the concentration of ammonium acetate in the ammonium acetate aqueous solution is 0.5-1.5 g / L, and sodium ascorbate is contained as a stabilizer; Flow rate: 4-6 mL / min.

8. The method according to claim 7 18 The F-MFPBG automated labeling method is characterized by: The mobile phase has a volume ratio of acetonitrile to ammonium acetate aqueous solution of 30:70, an ammonium acetate concentration of 0.828 g / L, and a sodium ascorbate concentration of 2.7 g / L; the flow rate is 5 mL / min.

9. The one according to claim 1 18 The F-MFPBG automated labeling method is characterized by: In step g, the stabilizer-containing saline solution is a saline solution containing 0.5-1.0 mg / mL sodium ascorbate.

10. A kind 18 The application of F-MFPBG is characterized by: This is used to prepare a myocardial sympathetic nerve imaging agent; the myocardial sympathetic nerve imaging agent is used for the diagnosis, prognostic assessment, or treatment effect monitoring of coronary heart disease, arrhythmia, or heart failure.

Images