Folate receptor-targeted drug, metal complex and preparation method and use thereof

Abstract

The application provides a folate receptor targeted drug, a metal complex and a preparation method and application thereof, and relates to the technical field of radio labeling. The folate receptor targeted drug has a structure as shown in formula I, and a metal complex is prepared after being labeled by a radionuclide. The folate receptor targeted drug or the metal complex provided by the application can be used for diagnosing and / or treating diseases with overexpression of folate receptors. The folate receptor targeted drug has the advantages of high in-vivo stability, strong specificity, good targeting property and the like.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. CN202111647679.X, filed on December 30, 2021, entitled "A folic acid receptor targeted drug, a metal complex and its preparation method and use", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of radiolabeling technology, and in particular to a folic acid receptor-targeting drug, a metal complex, its preparation method and uses. Background Technology

[0004] The folate receptor (FR) is a glycoprotein linked to the cell membrane via a polysaccharide phosphatidylinositol. FR exhibits high affinity and specificity for folate and its derivatives, such as methyltetrahydrofolate. FR primarily comprises four subtypes: α, β, γ, and δ. FRα is the most prevalent folate receptor, exhibiting restricted expression in normal tissues but overexpression in epithelial-derived tumors, with expression levels increasing with tumor progression. Drugs or other substances bound to folate can enter cells and exert their effects through FRα-mediated endocytosis. Monoclonal antibodies targeting the folate receptor show great promise in the diagnosis and treatment of tumors.

[0005] In recent years, there has been increasing research on radionuclide-labeled folic acid chelate imaging agents. 111 In-DTPA-folate is the first FR tumor imaging agent to enter and complete phase II clinical trials. It can distinguish between benign and malignant tumors relatively well, but its effect in diagnosing recurrent ovarian cancer and malignant solid tumors of the endometrium is not ideal (Journal of Nuclear Medicine, 2003(44):700-707). EC20 is a peptide containing a folic acid structural analogue. 99m Tc-EC20 is taken up in high amounts in tumor cells, has a short half-life, and can be excreted unchanged in the kidneys. However, after completing phase I and phase II clinical trials for ovarian cancer, cervical cancer, and kidney cancer in 2015, there has been no further progress (Journal of Nuclear Medicine, 2004(45):857-866). 67 / 68 Ga-DOTA-folate has limited clinical application due to its poor in vivo stability (Eur J Nucl Med MolImaging, 2011, 38: 108-119). 18F-click-folate can show specific uptake in tumor parts with high expression of FR, but the imaging effect is affected due to high abdominal uptake (bioconjugate Chemistry, 2008, 19(12):2462-2470). At present, most of the researches on FR-mediated radiopharmaceuticals are limited to the experimental stage, and the drugs entering the clinic are also terminated due to some limitations.

[0006] In view of this, the present application is proposed. SUMMARY

[0007] In view of the defects of the prior art, one of the purposes of the present application is to propose a new folate receptor targeted drug and a preparation method thereof.

[0008] The second purpose of the application is to provide a metal complex and a preparation method thereof.

[0009] The third purpose of the application is to provide the use of the above folate receptor targeted drug and / or metal complex.

[0010] The purpose of the present application is achieved by the following technical solutions:

[0011] The present application provides a folate receptor targeted drug, which is a compound shown in the following formula I or an isomer thereof,

[0012]

[0013] wherein L is selected from substituted or unsubstituted aryl diamine, substituted or unsubstituted heteroaryl diamine, substituted or unsubstituted heterocyclic diamine, substituted or unsubstituted amino alcohol, substituted or unsubstituted alkyl glycol group, or polyethylene glycol derivative of the above-mentioned groups; L is connected to the two side structure fragments through -NH, -N or -O groups;

[0014] R1 is a bifunctional chelating agent;

[0015] R2 is selected from hydrogen or methyl, or is null;

[0016] R3 is hydrogen, or is null.

[0017] Specifically, is a folate molecule structure fragment, when R2 is hydrogen or methyl, the -NR2 adjacent carbon atom has chirality, and the configuration can be R or S or RS mixed rotation.

[0018] Further, the folate molecule structure fragment is selected from the following structures:

[0019]

[0020] It is understood that L is -NH, -N, -O at both ends, i.e. L is independently selected from imino, nitrogen atom or oxygen atom at both ends.

[0021] Further, L is selected from the following structures:

[0022]

[0023] Any one of the groups, m, n, o, p and q are natural numbers from 1 to 9.

[0024] Preferably, L is selected from

[0025]

[0026] More preferably, L is

[0027]

[0028] The bifunctional chelator is selected from any one of iminodiacetic acid, ethylenediaminetetraacetic acid (EDTA), triethylenetetramine (TETA), diethylenetriamine-N,N,N',N',N"-pentaacetic acid (DTPA), bis-(carboxymethyl imidazole) glycine, 6-hydrazinopyridine-3-carboxylic acid (HYNIC), N,N"-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N"-diacetic acid (HEBD-CC), N'-{5-[acetyl(hydroxy)amino]pentyl}-N-[5-({4-[(5-aminopentyl)(hydroxy)amino]-4-oxobutanoyl}amino)pentyl]-N-hydroxysuccinamide (DFO), 1,4,7,10-tetraazacyclododecane-N,N',N,N'-tetraacetic acid (DOTA), 2-(4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)pentanedioic acid (DOTAGA), 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA), 2-(4,7-bis(carboxymethyl)-1,4,7-triazacyclonon-1-yl)pentanedioic acid (NODAGA), and derivatives thereof.

[0029] Preferably, the bifunctional chelator is selected from DOTA or NOTA.

[0030] In particular, the folate receptor-targeted drug is selected from any one of the compounds represented by the following structural formulae:

[0031]

[0032]

[0033]

[0034] The embodiment of the present application also provides a preparation method of the folate receptor-targeted drug by a solid phase synthesis method, so as to realize specific targeting combination with FRa.

[0035] The embodiment of the present application also provides a metal complex comprising a radionuclide and the folate receptor-targeted drug. 18 F], 64 Cu, 67 Cu, 67 Ga, 68 Ga, 89 Zr, 86 Y, 90 Y, 99m Tc, 111 In, 153 Sm, 166 Ho, 177 Lu, 186 Re, 188 Re, 211 At, 212 Bi, 213 Bi, 225 Ac, 227 Th. The probe of the present application is used in a small animal experiment to investigate the biodistribution, targeting and specificity of the probe in vivo.

[0036] The embodiment of the present application also provides a pharmaceutically acceptable composition comprising the folate receptor-targeted drug or the metal complex, or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable excipient.

[0037] The embodiment of the present application also provides a use of the folate receptor-targeted drug or the metal complex or the pharmaceutically acceptable composition in diagnosis and / or treatment of a folate receptor overexpression disease.

[0038] Further, the disease is brain tumor, breast cancer, ovarian cancer, gastric cancer, lung cancer, kidney cancer, mesothelial tissue cancer, endometrial cancer, colorectal cancer, cervical cancer, head and neck tumor, testicular cancer.

[0039] The folate receptor-targeted drug provided by the embodiment of the present application is composed of a folate molecular structure fragment, a linker L and a bifunctional chelator R1. In order not to change the affinity with FR, the embodiment of the present application introduces the linker L on the basis of the structure of the folate drug to adjust the residence time of the compound in vivo, so as to realize high tumor-specific uptake after being labeled by a radionuclide. The metal complex provided by the present application is mainly excreted through the kidney, and can be used for tumor diagnosis or treatment targeting the folate receptor. The folate receptor-targeted drug provided by the present application can specifically target the FRa receptor, and the preparation method is simple; the metal complex has high labeling rate, good in-vivo and in-vitro stability, strong specificity, and high diagnostic and therapeutic efficiency. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is the LC-MS spectrum of compound A provided in Example 1 of this invention;

[0042] Figure 2 This is provided in Embodiment 7 of the present invention. 68 Radioactivity spectrum of Ga-1;

[0043] Figure 3 This is provided in Embodiment 10 of the present invention. 68 Biodistribution map of Ga-1 in ICR mice;

[0044] Figure 4 This is provided in Embodiment 11 of the present invention. 68 microPET images of Ga-1 in SKOV3 tumor-bearing mice;

[0045] Figure 5 The Al[ provided in Embodiment 12 of the present invention] 18 F]-1 microPET images of SKOV3 tumor-bearing mice;

[0046] Figure 6 This is provided in Embodiment 13 of the present invention. 68 microPET images of Ga-2 in SKOV3 tumor-bearing mice;

[0047] Figure 7 This is provided in Embodiment 14 of the present invention. 68 microPET images of Ga-1 in SKOV3 tumor-bearing rats during the blockade assay;

[0048] Figure 8 This is provided in Embodiment 15 of the present invention. 68 microPET images of Ga-1 in PC-3 tumor-bearing mice. Detailed Implementation

[0049] The features and performance of the present invention will be further described in detail below with reference to the embodiments. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available products.

[0050] The features and characteristics of the present application are further described in detail below in connection with the embodiments.

[0051] Example 1

[0052] The present embodiment provides a folate receptor targeted drug A, the structural formula of which is as follows:

[0053]

[0054] The present embodiment also provides a preparation method of the folate receptor targeted drug A, which is prepared according to the following synthesis path:

[0055]

[0056] The specific operation is as follows:

[0057] Resin preparation: Wang resin (1.00 mmol, 1.04 eq), Fmoc-Glu(OAlly)-OH (3.00 mmol, 3.00 eq), HOAT (3.00 mmol, 3.00 eq), DIC (3.00 mmol, 3.00 eq) and DMAP (0.30 mmol, 0.3 eq) are dissolved in a DMF (5.00 mL) solution. The mixture is stirred at 20°C under N2for 3h. Then Ac2O / DIEA / DMF (10 / 5 / 85) 5.00 mL is added, and the stirring is continued under N2for 15 min. The resin is washed with DMF (20.0 mL*5), and then the mixture is filtered to obtain resin 1.

[0058] Deprotection: DMF solution (20% piperidine, 40.0 mL) is added to the above resin 1, and stirred under N2for 20 min. Then it is washed with DMF (40.0 mL*5) and filtered.

[0059] Coupling: A solution of pteroic acid (1.50 eq) in DMSO (6 mg / ml), a solution of HOAT (3.00 eq) and EDCI (3.00 eq) in DIEA (3.00 eq) is added to the above resin, and stirred at 20°C under N2for 12 h. It is washed with DMF (40.0 mL*5) and filtered to obtain resin 2.

[0060] Deprotection: A solution of PhSiH (10.0 eq) and Pd(PPh3)4in DMF (40.0 mL) is added to the above resin 2, and stirred under N2for 1 h. It is washed with DMF (40.0 mL*5) and then filtered to obtain resin 3.

[0061] Coupling: A solution of piperazine (3.00 eq) protected with a single Boc in DMSO (6 mg / mL), and a solution of HOAT (2.00 eq) and DIC (2.00 eq) in DIEA (0.5 mL) were added to resin 3 and stirred at 20 °C under N2 conditions for 12 h. The resin was washed with DMF (40.0 mL * 5) and filtered to obtain resin 4.

[0062] Pyrolysis: Resin 4 was washed three times with methanol and dried under vacuum. Then, it was treated with 5 mL of TFA for 45 min. The peptide was precipitated with cold isopropyl ether, centrifuged (3000 rpm, 2 min), and washed twice with isopropyl ether. The crude peptide was dried under vacuum for 2 h. The crude peptide was purified by preparative-high performance liquid chromatography (A: H₂O (0.075% TFA), B: ACN) to obtain a yellow solid as compound 4' (0.08 g, 119 μmol), yield: 11.9%, purity: 93%.

[0063] 1 H NMR(500MHz,Chloroform-d)δ8.47(t,J=6.0Hz,1H),7.71–7.65(m,2H),6.81–6.74(m,2H),6.59(d,J=7.1Hz,1H),6.27(d,J=7.1Hz,1H),4.9 4(dd,J=8.9,2.1Hz,2H),4.33(q,J=11.7Hz,1H),3.57(ddd,J=6.4,3.8,1.1Hz,4H),2.98–2.89(m,4H),2.50–2.34(m,2H),1.87–1.76(m,2H).

[0064] Coupling: A mixture of compound 4' (0.08 g, 119.32 μmol, 1 eq) and DIEA (74.2 mg, 574 μmol, 0.1 mL, 4.81 eq) was dissolved in 8.00 mL of DMSO and stirred at 25 °C for 0.5 h. Then, 2-[4-(carboxymethyl)-7-[2-(4-nitrophenoxy)-2-oxo-ethyl]-1,4,7-triazol-1-yl]acetic acid (NOTA-PNP) (55.7 mg, 131 μmol, 1.1 eq) was added. Stirring was continued at 25 °C for 1 h. The reactants were purified by preparative-HPLC (TFA) to give a yellow solid product A (22.0 mg, 26.9 μmol), yield 22.5%, HPLC purity 97.5%.

[0065] LCMS: 398.4 [M / 2+H] + 795.5 [M+H] + .

[0066] 1 H NMR (500 MHz, Chloroform-d) δ 8.47 (s, 1H), 7.74 - 7.68 (m, 2H), 6.82 - 6.75 (m, 2H), 6.59 (d, J = 7.1 Hz, 1H), 6.27 (d, J = 6.9 Hz, 1H), 4.99 (d, J = 8.9 Hz, 2H), 4.32 (q, J = 11.7 Hz, 1H), 3.53 (s, 6H), 3.58 - 3.48 (m, 2H), 3.46 (d, J = 0.9 Hz, 4H), 3.17 (d, J = 4.1 Hz, 2H), 2.60 - 2.50 (m, 12H), 2.48 - 2.37 (m, 2H), 1.83 - 1.70 (m, 2H).

[0067] Example 2

[0068] This example provides a folate receptor targeted drug B, the structure of which is as shown below:

[0069]

[0070] The synthesis steps refer to Example 1, and 2-[4-(carboxymethyl)-7-[2-(4- nitrophenoxy)-2-oxo-ethyl]-1,4,7-triazol-1-yl]acetic acid (NOTA-PNP) in Example 1 is replaced by 2,2',2"-(10-(2-(4-nitrophenoxy)-2-acetyloxy)-1,4,7,10- tetraazacyclododecane-1,4,7-triyl)triacetic acid (DOTA-PNP).

[0071] 1 H NMR (500 MHz, Chloroform-d) δ 8.47 (s, 1H), 7.74 - 7.68 (m, 2H), 6.82 - 6.75 (m, 2H), 6.59 (d, J = 7.0 Hz, 1H), 6.27 (d, J = 7.1 Hz, 1H), 4.99 (d, J = 8.9 Hz, 2H), 4.32 (q, J = 11.7 Hz, 1H), 3.58 - 3.48 (m, 8H), 3.46 (d, J = 0.7 Hz, 6H), 3.17 (d, J = 4.0 Hz, 2H), 2.56 (d, J = 1.8 Hz,

[0072] 16H), 2.48 - 2.37 (m, 2H), 1.83 - 1.70 (m, 2H).

[0073] Example 3

[0074] This example provides a folate receptor targeted drug C, the structure of which is as shown below:

[0075]

[0076] The synthetic procedure is referenced to Example 1, replacing piperazine in Example 1 with 3-(2-hydroxyethoxy)-l-(piperazin-l-yl)propan-l-one.

[0077] 1 H NMR (500 MHz, Chloroform-d) δ 8.47 (s, 1H), 7.72 - 7.65 (m, 2H), 6.82 - 6.76 (m, 2H), 6.62 - 6.51 (m, 1H), 6.27 (d, J = 6.9 Hz, 1H), 4.99 (d, J = 8.9 Hz, 2H), 4.38 - 4.26 (m, 3H), 3.87 - 3.73 (m, 2H), 3.61 (td, J = 7.1, 2.0 Hz, 2H), 3.58 - 3.54 (m, 5H), 3.54 - 3.42 (m, 7H), 3.17 (d, J = 4.1 Hz, 2H), 2.61 - 2.50 (m, 14H), 2.39 - 2.28 (m, 2H), 2.09 - 1.96 (m, 2H).

[0078] Example 4

[0079] This example provides a folate receptor targeted drug D, the structure of which is shown below:

[0080]

[0081] The synthetic procedure is referenced to Example 1, replacing pterin in Example 1 with 4-[[[(6R)-2-amino-3,4,5,6,7,8-hexahydro-4-oxo-6-pteridinyl]methyl]amino]- benzoic acid.

[0082] 1 H NMR (500 MHz, Chloroform-d) δ 7.76 - 7.70 (m, 2H), 7.53 (s, 2H), 6.65 - 6.58 (m, 2H), 4.32 (q, J = 11.7 Hz, 1H), 3.68 - 3.58 (m, 1H), 3.58 - 3.49 (m, 8H), 3.49 - 3.42 (m, 7H), 3.40 - 3.34 (m, 1H), 3.17 (d, J = 4.1 Hz, 2H), 2.60 - 2.50 (m, 12H), 2.48 - 2.37 (m, 2H), 1.83 - 1.70 (m, 2H).

[0083] 3.34 (m, 1H), 3.17 (d, J = 4.1 Hz, 2H), 2.60 - 2.50 (m, 12H), 2.48 - 2.37 (m, 2H), 1.83 - 1.70 (m, 2H).

[0084] Example 5

[0085] This example provides a folate receptor targeted drug E, the structure of which is shown below:

[0086]

[0087] Synthetic procedure reference example 1, replacing piperazine in example 1 with 2,5-dimethylamine-thiazole.

[0088] 1 H NMR (500 MHz, Chloroform-d) δ 8.47 (s, 1H), 7.73 - 7.67 (m, 2H), 7.51 (s, 1H), 6.82 - 6.76 (m, 2H), 6.59 (d, J = 7.1 Hz, 1H), 6.27 (d, J = 6.9 Hz, 1H), 4.99 (d, J = 8.9 Hz, 2H), 4.77 (dd, J = 8.0, 0.9 Hz, 2H), 4.55 (dd, J = 8.7, 0.7 Hz, 2H), 4.32 (q, J = 11.7 Hz, 1H), 3.46 (d, J = 1.0 Hz, 4H), 3.21 (s, 2H), 2.60 - 2.50 (m, 12H), 2.38 - 2.30 (m, 1H), 2.30 - 2.20 (m, 1H), 1.79 - 1.65 (m, 2H).

[0089] Example 6

[0090] This example provides a folate receptor targeted drug F, the structure of which is as shown below:

[0091]

[0092] Synthetic procedure reference example 1, replacing pterin in example 1 with 4-[[(6R)2-amino-3,4,5,6,7,8-hexahydro-5-methyl-4-oxo-6-pteridinyl]methyl]amino]- benzoic acid.

[0093] 1 H NMR (500 MHz, Chloroform-d) δ 7.76 - 7.70 (m, 2H), 7.61 (s, 2H), 6.66 - 6.59 (m, 2H), 4.32 (q, J = 11.7 Hz, 1H), 3.90 - 3.81 (m, 1H), 3.63 - 3.42 (m, 16H), 3.17 (d, J = 4.1 Hz, 2H), 2.92 (d, J = 1.6 Hz, 3H), 2.60 - 2.50 (m, 12H), 2.48 - 2.37 (m, 2H), 1.83 - 1.70 (m, 2H).

[0094] Example 7

[0095] This example provides a folate metal complex 68Ga-1, the structure of which is shown below:

[0096]

[0097] The compound A solution (20 μL, 1 mg / mL) prepared in Example 1 and the pre-processed 68 The GaCl3sodium acetate buffer solution (1.1 ml) was mixed thoroughly, the pH of the reaction solution was adjusted to keep at 4-4.5, and the labeling was marked at room temperature. The radiochemical purity was 95.5%, and the HPLC radiochromatogram is shown in Figure 2 .

[0098] Identification:

[0099] Standard preparation: The compound A solution (5 ml, 10 mg / ml) prepared in Example 1 was mixed with the GaCl3sodium acetate buffer solution (5 ml, 20 mg / ml, pH 4-4.5), and then reacted at room temperature for 24 h. The product was separated and purified by preparative HPLC (YMC-Pack ODS-A-HG, 10 μm, 150 x 20 mm, 5 ml / min, 20% ethanol and 80% injection water mixed solution, UV 254 nm). The obtained solution was freeze-dried to obtain a white solid powder.

[0100] HPLC: The UV peak Rt=3.382 min and the radioactivity peak Rt=3.785 min of the standard were consistent with the peak position of the standard.

[0101] The labeled product 68 Ga-1 was respectively placed in mouse serum and normal saline, and incubated in a water bath at 37°C for 12 h. The radiochemical purity was 94% and 95%, respectively, indicating that it had good in vitro stability.

[0102] Example 8

[0103] This example provides a folate metal complex Al[ 18 F]-1, the structure of which is shown below:

[0104]

[0105] A 2 mM AlCl3solution was prepared in 0.1 mM, pH 4.0 acetic acid buffer. 0.1 mL of 0.1 mM, pH 4.0 acetic acid buffer and 6 μL of AlCl3solution were added to 50-120 MBq 18 F -(0.1 mL) was placed at room temperature for 5 min, then 5 μL (1 mg / mL) of the compound A solution prepared in Example 1 was added, and the reaction was carried out at 110 °C for 10 min to obtain the target compound. The target compound was separated and purified using a Sep-pak C18 Column Light. Before use, the Sep-pak column was activated with 10 mL of anhydrous ethanol and 10 mL of high-purity water. The target compound Al was eluted sequentially with 0.5 mL of ethanol and 3 mL of physiological saline. 18 F-1 has a radiochemical purity of 94.4%.

[0106] Identification:

[0107] Preparation of standard: Compound A (500 μg) prepared in Example 1, 0.8 mL of acetonitrile, and 0.05 mL of 0.4 M AlCl3 aqueous solution were added to 0.5 mL of fluorine acetate solution and reacted at 110 °C for 10 min. The resulting product was purified by preparative HPLC.

[0108] HPLC: The UV peak of the standard was at Rt = 4.129 min, and the radioactive peak was at Rt = 4.305 min, which are consistent with the peak positions of the standard.

[0109] Label product Al[ 18 F]-1 was placed in mouse serum and physiological saline, respectively, and incubated in a water bath at 37°C for 2 hours. The radiochemical purity was 92.8% and 93.9%, respectively, indicating that it has good in vitro stability.

[0110] Example 9

[0111] This embodiment provides a folic acid metal complex. 68 Ga-2 has the following structure:

[0112]

[0113] Preparation of complexes according to Example 7 68 Ga-2, with compound F replaced by compound A in Example 7, has a radiochemical purity of 95.6%.

[0114] Identification:

[0115] Preparation of standard: The standard Ga-2 was prepared according to Example 7, except that compound A in Example 7 was replaced with compound F.

[0116] HPLC: The UV peak of the standard was at Rt = 4.677 min, and the radioactive peak was at Rt = 4.830 min, which are consistent with the peak positions of the standard.

[0117] Labeled products 68Ga-2 was incubated in mouse serum and normal saline respectively at 37℃ for 12h, and the radiochemical purity was 94.5% and 95.8% respectively, which indicated that Ga-2 had good stability in vitro.

[0118] Example 10

[0119] ICR mice were randomly divided into 5 groups by drawing lots, and each group had 4 mice. The mice were injected with 0.1ml (3.7MBq) 68 Ga-1 in the tail vein. The blood was taken by heart puncture and the mice were euthanized at 5min, 15min, 30min, 60min and 120min after the injection of Ga-1. The important organs were taken and weighed. The radioactivity was counted by a gamma counter. The radioactivity uptake of each organ was calculated, and the results were shown in Table 1. Figure 3

[0120] Results: 68 Ga-1 was quickly cleared from the blood. The radioactivity uptake of normal tissues such as heart, liver, spleen and lung was low. The radioactivity uptake of most organs was less than 2%ID / g at 120min. Ga-1 was mainly excreted through the kidney.

[0121] Example 11

[0122] A nude mouse with human ovarian cancer (SKOV3: high expression of FRα) was used, and the tumor length was 0.8cm. The nude mouse was fed with no folic acid diet for one week before the imaging. The nude mouse was anesthetized by inhaling isoflurane, and was injected with Ga-1 (3.7MBq / 0.1mL) in the tail vein. 68 The image acquisition and processing parameters were as follows: energy peak 350KeV-650KeV, timing window 3.438ns, acquisition time 600s, and reconstruction method OSEM3D / MAP iterative reconstruction. The tomographic image analysis and tumor boundary delineation were performed by Inveon Research Workplace to obtain the regions of interest (ROI), and the tumor radioactivity uptake (%ID / g) and tumor / liver ratio were calculated. The PET imaging results were shown in Table 2. Figure 4

[0123] Results: 68 Ga-1 was mainly excreted through the urinary system (kidney and bladder). The tumor radioactivity uptake was continuously increased from 0.5h to 2.5h. Ga-1 had high affinity to FRα, and had good imaging effect, which was a good imaging agent.

[0124] Example 12​​

[0125] MicroPET imaging was performed on tumor-bearing mice according to Example 11, and the tail vein injection method described in Example 11 was used. 68 Replace Ga-1 (3.7 MBq / 0.1 mL) with Al[ 18 F]-1 (3.7 MBq / 0.1 mL), PET imaging results are as follows Figure 5 As shown.

[0126] Result: Intravenous injection of Al[ 18 Following administration of drug F]-1, tumor radioactive uptake increased continuously within 0.5–3.5 hours, while uptake in other non-target organs remained low. This indicates that Al[ 18 F]-1 drugs are mainly excreted through the urinary system, have high specificity, and provide good imaging results, making them a relatively good imaging agent.

[0127] Example 13

[0128] MicroPET imaging was performed on tumor-bearing mice according to Example 11, and the tail vein injection method described in Example 11 was used. 68 Replace Ga-1 (3.7 MBq / 0.1 mL) with 68 Ga-2 (3.7 MBq / 0.1 mL), PET imaging results are as follows: Figure 6 As shown.

[0129] Result: Intravenous injection 68 Following Ga-2 drug administration, tumor uptake peaked at 0.5 hours, with no significant uptake observed at 2.5 hours. Clearance from other non-target organs was also rapid. 68 Ga-2 drugs are mainly excreted through the urinary system, have high specificity, and produce good imaging results.

[0130] Example 14

[0131] MicroPET imaging of tumor-bearing mice was performed according to Example 11, with the same procedure performed via tail vein injection as in Example 11. 68 FR was blocked by injecting Ga-1 (3.7 MBq / 0.1 mL) dissolved in normal saline 20 min before administration. PET imaging results are as follows. Figure 7 As shown.

[0132] Result: Intravenous injection 68 Following Ga-1 administration, tumor radioactive uptake was extremely low at 0.5 hours, and no significant uptake was observed between 1.5 and 2.5 hours, compared to the non-blocking group (Example 11), where tumor uptake was almost nonexistent. (Note:) 68 Ga-1 drugs can specifically target FRα in vivo, making them relatively good imaging agents.

[0133] Example 15

[0134] The tumor-bearing mice were imaged by microPET according to the method of Example 11, and the tumor-bearing nude mice in Example 11 were replaced by human prostate cancer (PC3: FRα low expression) nude mice, and the PET imaging results were as shown in Figure 8. Figure 8

[0135] Results: After intravenous injection of Ga-1 drug, there was no significant uptake of radioactivity in the tumor within 0.5-2.5h, and the uptake of other non-target organs was also low except for the kidney and bladder. 68 Ga-1 drug is mainly excreted through the urinary system, has strong specificity for FRα, and is a good imaging agent. 68 Ga-1 drug is mainly excreted through the urinary system, has strong specificity for FRα, and is a good imaging agent.

[0136] The preferred embodiments of the present application are described in detail above. It should be understood that those of ordinary skill in the art can make active modifications and changes to the present application without creative labor based on the concept of the present application. Therefore, any technical solutions obtained by logical analysis, reasoning or limited experiments based on the existing technology according to the concept of the present application shall be within the scope of protection determined by the claims.​

Claims

1. A folate receptor-targeted drug, characterized in that, It is a compound shown in the following formula I, wherein R1 is a bifunctional chelator; R2 and R3 are both null; or R2 is hydrogen or methyl, and R3 is hydrogen; L is The bifunctional chelator is selected from any one of 1,4,7,10-tetraazacyclododecane-N,N',N,N'-tetraacetic acid, 1,4,7-triazacyclononane-1,4,7-triacetic acid.

2. A folate receptor-targeted drug, characterized in that, selected from the following structural formula:

3. The folic acid receptor-targeting drug according to any one of claims 1 and 2, characterized in that, The folate receptor targeted drug is prepared by a solid phase synthesis method.

4. A metal complex comprising a radionuclide and the folate receptor targeted drug of any one of claims 1 or 2.

5. The metal complex of claim 4, wherein, the radionuclide is selected from any one of Al[ 18 F], 64 Cu, 67 Cu, 67 Ga, 68 Ga, 89 Zr, 86 Y, 90 Y, 99m Tc, 111 In, 153 Sm, 166 Ho, 177 Lu, 186 Re, 188 Re, 211 At, 212 Bi, 213 Bi, 225 Ac, 227 Th.

6. A pharmaceutically acceptable composition comprising the folate receptor targeted drug of any one of claims 1 or 2, or the metal complex of claim 4 or 5, and a pharmaceutically acceptable excipient.

7. Use of the folate receptor targeted drug of any one of claims 1 or 2, or the metal complex of claim 4 or 5, or the pharmaceutically acceptable composition of claim 6 in the preparation of a medicament for the diagnosis and / or treatment of a disease overexpressing folate receptors.

8. Use according to claim 7, characterized in that, The medicament is a medicament for the diagnosis and / or treatment of brain tumor, breast cancer, ovarian cancer, gastric cancer, lung cancer, kidney cancer, mesothelial tissue cancer, endometrial cancer, colorectal cancer, cervical cancer, head and neck tumor, testicular cancer.

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