Radiolabelled aminomannose derivatives, methods for their preparation and use

Abstract

This invention relates to the fields of radiopharmaceutical chemistry and clinical nuclear medicine, specifically to... 188 Re or 186 Preparation and application of Re-labeled aminomannose derivatives. 188 Re or 186 The structure of the Re-labeled aminomannose derivative is shown in (I). It exhibits good stability, high tumor uptake and retention, rapid blood clearance, and a high target / non-target ratio, making it a novel radiotherapy-integrated drug for tumor treatment worthy of promotion. (I)

Description

Technical Field

[0001] This invention relates to the fields of radiopharmaceutical chemistry and clinical nuclear medicine, specifically to radiorhenium-labeled aminomannose derivatives, their preparation methods, and applications. Background Technology

[0002] Tumor cells differ significantly from normal human cells in energy metabolism and biosynthesis. Tumor cells exhibit rapid proliferation compared to normal cells, thus requiring substantial energy expenditure to sustain rapid cell division. To meet this need, tumor cells require the uptake of more glucose for energy. Mannose, as a C-2 epimer of glucose, can, like glucose, enter tumor cells via glucose transporters. Based on this, we previously developed a… 99m Tc-labeled isonitrile mannose derivatives ([ 99m [Tc]Tc-CN7DM) is used for tumor imaging (Patent No.: ZL 2021 10839524.X). This imaging agent exhibits high tumor uptake in tumor-bearing mice, rapid blood clearance, and low uptake in non-target tissues, demonstrating good potential for clinical translation. Further preparations were made to... 99m The accompanying medicine box for Tc-CN7DM, we refer to [ 99m Tc]Tc-methoxyisobutylisocyanate ([ 99m The preparation scheme of the Tc-MIBI lyophilized kit was used to prepare the cuprous tetrafluoroborate complex salt [Cu(CN7DM)4]BF4 of CN7DM ligand, and the [Tc-MIBI] lyophilized kit was successfully prepared. 99m The medicine box for Tc-CN7DM meets all quality inspection standards (patent application number: 202510358861.5).

[0003] With the widespread clinical application of radionuclides, the integration of radionuclide diagnosis and therapy has become an important development direction in the field of precision medicine. This strategy achieves integration of diagnosis and therapy by coupling diagnostic and therapeutic radionuclides to the same ligand. Rhenium and technetium belong to the same group and have similar chemical properties. 99m Radiolabeling of ligands corresponding to Tc complexes with rhenium allows for the preparation of therapeutic probes. Currently, commonly used therapeutic radioactive rhenium isotopes include... 186 Re and 188 Re, where 186 Re is primarily obtained from reactors and is capable of emitting beta rays (maximum energy E) used in tumor therapy. βmax = 1.07 MeV) and gamma rays (E) used for SPECT imaging γ = 137 keV), with a half-life of 3.72 days; while 188 Re can be commercialized 188 W-188 The Re generator is capable of emitting beta rays (maximum energy E) used for tumor therapy. βmax = 2.12 MeV) and gamma rays (Eγ = 155.04 keV) used for SPECT imaging, with a half-life of 16.9 h, are both ideal radionuclides for both diagnosis and treatment.

[0004] Therefore, in order to further expand the probe [ 99m Application scenarios of Tc]Tc-CN7DM and exploration of the possibility of achieving integrated diagnosis and treatment with single molecules, therefore, preparation of [ 99m Corresponding radiopharmaceuticals for the treatment of Tc-CN7DM 186 Re]Re-CN7DM and [ 188 Re]Re-CN7DM has significant scientific value and clinical application potential, and is also an important task facing this field. Summary of the Invention

[0005] The purpose of this invention is to provide a radioactive rhenium-labeled aminomannose derivative, its preparation method, and its application. The label prepared by this invention can be specifically taken up by tumor cells, exhibiting high uptake and good retention properties in tumors. 188 Re / 186 The nuclide properties of Re enable integrated tumor diagnosis and treatment.

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

[0007] A radioactive rhenium-labeled aminomannose derivative, wherein the structural formula (I) is:

[0008]

[0009] (I)

[0010] This derivative exhibits good tumor targeting and high tumor uptake, with low uptake in non-target tissues, making it a novel, high-performance, integrated diagnostic and therapeutic drug.

[0011] The present invention also provides the application of the above-mentioned markers in the field of tumor diagnosis and treatment.

[0012] Preferably, in the above-mentioned markers, the radioactive nuclide M is... 186 Re, 188 Re.

[0013] Most preferably, in the above-mentioned markers, the radionuclide is... 188 Re, the structural formula of the marker is (II):

[0014]

[0015] (II)

[0016] The beneficial effects of this invention are as follows: This invention provides a radioactive rhenium-labeled aminomannose derivative, its preparation method, and its application, which is beneficial for realizing radiopharmaceuticals for tumors. 99m Tc]Tc-CN7DM / [ 188 Re / 186 Re]Re-CN7DM is a compound with great potential for widespread application, and its integrated diagnosis and treatment approach is a valuable compound for application. Detailed Implementation

[0017] The present invention relates to a radioactive rhenium-labeled aminomannose derivative, its preparation method and application, the structure of which is shown in (I).

[0018] Its preparation steps mainly include two steps: the preparation of CN7DM cuprous complex salt [Cu(CN7DM)4]BF4 and the preparation of radioactive rhenium-labeled CN7DM.

[0019] a. Preparation of compound [Cu(CN7DM)4]BF4

[0020] Isocyanate activated ester compound 4 was prepared by formamide reaction, and compound 4 was amide condensed with D-mannosamine hydrochloride under alkaline conditions to prepare compound CN7DM. CN7DM was mixed with [Cu(CH3CN)4]BF4 and reacted at room temperature to prepare compound [Cu(CN7DM)4]BF4.

[0021] Its synthetic route is as follows:

[0022]

[0023] b. Preparation of radiolabeled rhenium complexes

[0024] Dissolve appropriate amounts of sodium citrate, L-cysteine, mannitol, and SnCl2·2H2O in physiological saline, adjust the pH to 2–3, then add an appropriate amount of [Cu(CN7DM)4]BF4 compound, followed by an appropriate amount of […]. 188 Re]NaReO4 or [ 186 The radiolabeled rhenium complex was prepared by reacting Re]NaReO4 at 100°C for 30 min and then purifying it. 188 Re]Re-CN7DM or [ 186 Re]Re-CN7DM.

[0025] The radioactive rhenium-labeled aminomannose derivative prepared by the above method has good in vitro stability. The biodistribution results in tumor-bearing mice show that the labeled complex has high tumor uptake, good retention, and a high tumor / non-target ratio, making it worthy of promotion as a novel therapeutic radiopharmaceutical.

[0026] The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention.

[0027] Example 1

[0028] 1. Preparation of compound [Cu(CN7DM)4]BF4

[0029] Compared to technetium-99m, rhenium-188 is more difficult to reduce, therefore its marking conditions are more stringent. 188 Re]NaReO4 requires reduction by the reducing agent SnCl2·2H2O under stronger acidic conditions (pH = 2–3), while the ligand CN7DM contains exposed isocyanate groups, which are easily degraded under acidic conditions. Therefore, this invention chooses to prepare the cuprous complex salt [Cu(CN7DM)4]BF4 for subsequent labeling. The specific synthesis steps are as follows:

[0030] Synthesis of compound 2: 10 g (63 mmol) of compound 1 was dissolved in DMF and 5 mL of formic acid was added. The mixture was heated under reflux at 110 °C for 4 h. After the reaction was completed, the mixture was allowed to stand at room temperature overnight. A white solid precipitated out. The mixture was filtered, the filter cake was washed with ethyl acetate, and dried under vacuum to give 9.73 g of white solid product, with a yield of 83%. 1 H NMR (400 MHz, DMSO-d6) δ 11.92 (s, 1H),8.21 – 7.41 (m, 2H), 3.01 (t, J = 5.3 Hz, 2H), 2.19 – 2.11 (m, 2H), 1.52 –1.39 (m, 2H), 1.37 – 1.32 (m, 2H), 1.24 – 1.19 (m, 6H).

[0031] Synthesis of Compound 3: Compound 2 (9.73 g, 52 mmol) and 2,3,5,6-tetrafluorophenol (TFP, 7.85 g, 47 mmol) were weighed into a round-bottom flask, dissolved in an appropriate amount of DCM, and stirred at room temperature for 30 min. Then, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI, 10.8 g, 56 mmol) was added, and the mixture was reacted overnight at room temperature. After the reaction was completed, the product was washed twice with saturated NaHCO3 solution and deionized water, respectively. The organic phase was collected, dried over anhydrous Na2SO4, filtered by rotary evaporation, and the organic phase was removed by rotary evaporation to give 14.56 g of pale yellow solid product, with a yield of 92%. 1H NMR (400 MHz, CDCl3) δ 8.16 (s, 1H),7.16 – 6.86 (m, 1H), 5.55 (s, 1H), 3.35 – 3.26 (m, 2H), 2.66 (td, J = 7.3,2.1 Hz, 2H), 1.76 (p, J = 7.2 Hz, 2H), 1.53 (p, J = 7.2 Hz, 2H), 1.45 – 1.30(m, 6H).

[0032] Synthesis of compound 4: Compound 3 (14.56 g, 43 mmol) was weighed, dissolved in an appropriate amount of DCM, and then Burgess reagent (12.4 g, 52 mmol) was added. The reaction was carried out overnight at room temperature. After the reaction was completed, the product was purified by column chromatography (PE:EA = 10:1, v / v), and dried under vacuum to give 7.84 g of yellow oily product, with a yield of 58%. 1 H NMR (400 MHz, CDCl3) δ 7.07 – 6.78 (m,1H), 3.38 (tt, J = 6.7, 1.9 Hz, 2H), 2.67 (t, J = 7.3 Hz, 2H), 1.78 (p, J =7.3 Hz, 2H), 1.73 – 1.61 (m, 2H), 1.53 – 1.31 (m, 6H).

[0033] Synthesis of compound CN7DM: D-mannosamine hydrochloride (DMAH, 1.0 g, 4.6 mmol) and sodium hydroxide (200 mg, 5.0 mmol) were weighed into a round-bottom flask. A suitable amount of methanol was added, and the mixture was stirred at room temperature for 30 min until the solid dissolved. Then, a methanol solution of compound 4 (1.74 g, 5.5 mmol) was added, and the reaction was allowed to proceed overnight at room temperature. After the reaction was complete, the solvent was removed by rotary evaporation, and the product was purified by column chromatography (DCM: MeOH = 5:1, v / v). After vacuum drying, 989 mg of a yellow solid product was obtained, with a yield of 65%. 1 H NMR (400 MHz, CD3OD) δ 4.96 (d, J = 1.6 Hz, 1H), 4.26 (dd, J = 4.7, 1.6 Hz, 1H), 4.03 – 3.93 (m, 1H), 3.82 – 3.77 (m, 1H), 3.74 (d, J = 9.6 Hz, 2H), 3.59 –3.51 (m, 1H), 2.29 – 2.22 (m, 2H), 1.69 – 1.57 (m, 4H), 1.45 – 1.32 (m, 8H).13 C NMR (101 MHz, CD3OD) δ 175.66, 153.87, 93.68, 72.12, 69.27, 67.16, 60.94,53.68, 41.10, 35.55, 28.81, 28.74, 28.21, 25.96, 25.52. HR-MS(ESI) forC 15 H 27 N2O6 + [M+H] + found 331.1869, calculated 331.1863.

[0034] Synthesis of compound [Cu(CN7DM)4]BF4: [Cu(CH3CN)4]BF4 (190 mg, 0.61 mmol) and compound CN7DM (800 mg, 2.43 mmol) were added sequentially to a 50 mL round-bottom flask, followed by the addition of an appropriate amount of methanol to dissolve the compound. After reacting at room temperature for 3 h, the mixture was allowed to stand at room temperature until a large amount of solid precipitated. The mixture was filtered, and the filter cake was washed with methanol. After vacuum drying, 876 mg of a yellow powder product was obtained, with a yield of 98%. 1 H NMR (600 MHz, CD3OD) δ 4.97 (s, 4H), 4.26 (d, J = 4.6Hz, 4H), 3.98 (dd, J = 9.7, 4.6 Hz, 4H), 3.82 – 3.80 (m, 4H), 3.77 – 3.73 (m,8H), MS (ESI) for [C 60 H 104 CuN8O 24 ] + [M] + , found 1383. 6551, calcd 1383.6459.

[0035] 2.[ 188 The mark of Re]Re-CN7DM

[0036] Dissolve 2.6 mg sodium citrate, 1.0 mg L-cysteine, 10 mg mannitol, and 2.10 mg SnCl2·2H2O in physiological saline. Adjust the pH to 2–3, then add 2 mg of compound [Cu(CN7DM)4]BF4, followed by freshly rinsed […]. 188 Re]NaReO4 was added to a final volume of 1.0 mL with physiological saline, and the reaction was carried out at 100°C for 30 min. After the reaction was completed and cooled to room temperature, the final product was purified by C18 column chromatography. 188 Re]Re-CN7DM.

[0037] 3. TLC identification

[0038] The radiochemical purity of the labeled substances was determined by thin-layer chromatography (TLC). Pure methanol was used as the developing solvent, and a polyamide film was used as the stationary phase. Under this system, the R0 of each radioactive component was determined. f The values ​​are shown in Table 1.

[0039] Table 1 188 Chromatographic results of each component in the polyamide film-methanol system (R) f value)

[0040] <![CDATA[[ 188 Re]ReO4 - ]]> <![CDATA[[ 188 Re]ReO2·xH2O]]> <![CDATA[[ 188 Re]Re-CN7DM]]> <![CDATA[R f ]]> 0 – 0.1 0 – 0.1 0.7 – 1.0

[0041] 4. In vitro stability studies

[0042] Take samples after 2 h, 4 h, and 6 h of storage. 188 The Re]Re-CN7DM labeled solution was identified by TLC to evaluate its in vitro stability.

[0043] The results showed no significant change in radiochemical purity after 6 hours of storage, indicating that [ 188 Re]Re-CN7DM exhibits good in vitro stability.

[0044] 5. Biodistribution experiment in tumor-bearing mice

[0045] Prepared [ 188 Re-CN7DM labeling solution (0.1 mL, 1.85 MBq / mL) was injected into mice bearing S180 tumors via the tail vein. The mice were anesthetized and sacrificed 120 min and 360 min after injection, respectively. Organs or tissues such as heart, liver, lung, kidney, spleen, stomach, bone, flesh, small intestine, tumor, blood, muscle, and thyroid were collected, weighed, and the radioactivity count of each organ or tissue was measured. The final result is expressed as (radioactivity count of organ or tissue / total radioactivity count after tail correction) / mass of organ or tissue, i.e., % ID / g, and the final result is expressed as % ID / g ± SD.

[0046] Table 2 [188 Biodistribution of Re]Re-CN7DM in mice bearing S180 tumors (n = 5, % ID / g, x ± SD)

[0047] tissues or organs 120 min 360 min Heart 0.96 ± 0.09 0.86 ± 0.13 liver 2.25 ± 0.41 2.32 ± 0.32 lung 0.59 ± 0.06 0.56 ± 0.17 kidney 2.56 ± 0.87 2.52 ± 0.38 spleen 0.57 ± 0.14 0.56 ± 0.17 Stomach 0.91 ± 0.14 0.50 ± 0.12 bone 0.69 ± 0.35 0.35 ± 0.27 Meat 0.55 ± 0.07 0.45 ± 0.10 intestinal 1.47 ± 0.80 0.34 ± 0.07 tumor 2.79 ± 0.78 2.37 ± 0.69 Blood 0.25 ± 0.03 0.13 ± 0.04 <![CDATA[Thyroid gland a > 0.03 ± 0.02 0.02 ± 0.01 Tumor / blood 11.38 ± 3.60 19.06 ± 5.88 Tumor / Flesh 5.17 ± 1.67 5.23 ± 0.78

[0048] a %ID

[0049] [ 188 The biodistribution results of Re-CN7DM are shown in Table 2. At 120 min and 360 min post-injection, tumor uptake was 2.79 ± 0.78% ID / g and 2.37 ± 0.69% ID / g, respectively, indicating high tumor uptake and good retention. At 120 min and 360 min post-injection, blood uptake was 0.25 ± 0.03% ID / g and 0.13 ± 0.04% ID / g, respectively, indicating low background blood uptake and rapid blood clearance. At 360 min post-injection, the tumor / blood ratio and tumor / tumor ratio were 19.06 ± 5.88 and 5.23 ± 0.78, respectively, showing a high target / non-target ratio, suggesting its potential as a novel radiopharmaceutical for integrated tumor diagnosis and treatment.

[0050] 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... 188 Re or 186 Re-labeled isonitrile aminosaccharide derivatives, their preparation methods, and applications are also within the scope of protection claimed in this invention.

Claims

1. A radioactive rhenium-labelled aminomannose derivative, characterised in that, The structural formula of the derivative is (I) (I)。 2. The preparation method of the compound according to claim 1, comprising the following steps: dissolving appropriate amounts of sodium citrate, L-cysteine, mannitol, and SnCl2·2H2O in physiological saline, adjusting the pH to 2–3, then adding an appropriate amount of [Cu(CN7DM)4]BF4 compound, followed by adding […]. 188 Re]NaReO4 or [ 186 The radiolabeled rhenium complex was prepared by reacting Re]NaReO4 at 100°C for 30 min and then purifying it. 188 Re]Re-CN7DM or [ 186 Re]Re-CN7DM.

3. Use of the radioactive rhenium-labelled aminomannose derivative according to claim 1 for the preparation of a tumour radiopharmaceutical.

Images