Small-molecule contrast agent as well as preparation method and application thereof
By constructing small-molecule contrast agents with symmetrical rigid frameworks, the problems of short blood circulation half-life and poor stability in existing technologies have been solved, achieving contrast agents with high CT values and high stability, reducing patient risks and synthesis complexity.
Patent Information
- Application Number
- CN202511664892.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-13
- Publication Date
- 2025-12-12
AI Technical Summary
Existing non-ionic small molecule iodine contrast agents have a short blood circulation half-life, resulting in a narrow vascular phase imaging window. They require high-pressure injection and large doses, increasing the patient's iodine load and risk of kidney disease. Furthermore, some patients experience allergic reactions. Their synthetic routes are lengthy or their molecular weight is too large, leading to poor stability.
A small molecule contrast agent was designed by reacting specific compounds in different solvents to construct a symmetrical rigid framework, ensuring that each molecule contains six iodine atoms. The water solubility, dilution stability and chemical stability were improved through synthetic route optimization.
Significantly high CT values and imaging performance were achieved at equimolar concentrations. The molecules maintained 100% purity after being placed in water for 40 hours, reducing the risk of degradation products and improving imaging signals and stability.
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Figure CN121108212A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of small molecule contrast agent, and particularly relates to a small molecule contrast agent, a preparation method and application thereof. BACKGROUND
[0002] The non-ionic small molecule iodine contrast agents widely used in the clinic at present mainly include iohexol, iopromide and iopamidol, and the core structures of which are all based on a triiodobenzene ring skeleton. Such compounds have lower solution viscosity, moderate osmotic pressure (close to physiological level), and good water solubility and rapid kidney clearance characteristics, thus having high short-term safety. However, the pharmacokinetic characteristics thereof also have significant limitations: the blood circulation half-life is extremely short (usually less than 30 minutes), and the compounds are mainly rapidly excreted out of the body through glomerular filtration, resulting in a narrow window of vascular phase imaging. Therefore, a high-pressure injector is often used for large-dose bolus injection in the clinic to ensure sufficient contrast enhancement effect, but this inevitably increases the total iodine load of the patient, and further increases the risk of contrast-induced nephropathy (CIN), especially in patients with renal dysfunction or diabetes. At the same time, some patients may have allergic reactions or even severe hypersensitivity reactions, which further restricts the long-term or repeated use thereof.
[0003] In recent years, researchers have tried to couple the triiodobenzene skeleton with polysaccharides, polymers or peptide segments to prolong the blood pool retention time and impart active targeting function. However, most of the systems have a sharp increase in viscosity due to the excessively large molecular weight, or the synthesis route is long and the batch difference is obvious, which hinders the clinical transformation. Although a divalent sugar group can be embedded in the binary triiodobenzene ring skeleton to maintain a molecular weight of <2000 Da and improve the water solubility and viscosity of the contrast agent, the stability thereof is not good.
[0004] Therefore, the prior art still needs to be further improved and promoted. SUMMARY
[0005] In view of the deficiencies of the prior art described above, the purpose of the present application is to provide a small molecule contrast agent, which has good dilution stability and higher contrast brightness.
[0006] To achieve this purpose, the technical scheme adopted by the present application is as follows: In a first aspect, a small molecule contrast agent has the following structure: .
[0007] In a second aspect, a preparation method of the small molecule contrast agent of the first aspect is provided, which comprises: a compound Dissolves in HATU, DIPEA and other compounds The mixture was heated and stirred to obtain the compound. ; The compound The compound was obtained by dissolving it in a mixed solution of piperidine and N,N-dimethylformamide and reacting it at room temperature. ; compound After dissolution, it is mixed with HATU, DIPEA and compound 4, and left overnight to obtain compound 4. ; Compound 5 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, and reacted at a preset temperature to obtain compound 5. ; After dissolving compound 6, it was combined with HATU, DIPEA, and other compounds. The mixture is then used to obtain the small molecule contrast agent.
[0008] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.
[0009] As a preferred technical solution, in the method for preparing the small molecule contrast agent, the equivalent ratio of compound 1 and compound 2 is 1:2-3; and the reaction temperature is 20℃-55℃.
[0010] As a preferred technical solution, in the method for preparing the small molecule contrast agent, the equivalent ratio of compound 4 to compound 4a is 1:1-1.5.
[0011] As a preferred technical solution, in the method for preparing the small molecule contrast agent, the equivalent ratio of compound 6 to compound 7 is 1:1-1.5.
[0012] As a preferred technical solution, in the method for preparing the small molecule contrast agent, the preset temperature is 0℃-24℃.
[0013] As a preferred technical solution, in the method for preparing the small molecule contrast agent, the volume ratio of dichloromethane to trifluoroacetic acid is 4-2:1.
[0014] Thirdly, the application of a small molecule contrast agent as described in the first aspect in targeted contrast imaging.
[0015] Beneficial Effects: Compared with existing technologies, the small molecule contrast agent provided by this invention ensures that each molecule contains six iodine atoms, and its water solubility, dilution stability, and viscosity are all superior to traditional formulations. Simultaneously, this small molecule contrast agent possesses a symmetrical rigid framework, which endows the molecule with excellent chemical stability. As shown in the stability test results, its purity remains 100% after being placed in water for 40 hours, far superior to the control compound YJY-86-2 (purity decreased to 82.4%). This ensures the reliability of the product during storage and use, and reduces the potential risks caused by degradation products. Attached Figure Description
[0016] Figure 1 shows the CT test results of a small molecule contrast agent with a concentration of 13.80 mmol / mL provided in an embodiment of the present invention; Figure 2 The results are from a CT test using a small molecule contrast agent with a concentration of 6.90 mmol / mL, as provided in this embodiment of the invention. Figure 3 This is a comparative HPLC chromatogram of the stability test (40 hours) of the contrast agent (6-H-6) provided by this invention in water; Figure 4 This is a comparative HPLC chromatogram of the stability test (40 hours) of the existing contrast agent with the serial number YJY-86-2 in water. Detailed Implementation
[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. The invention will now be described in detail with reference to the embodiments. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.
[0018] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that when the terms "comprising" and / or "package" are used in this specification… When "includes", it indicates the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0019] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values of the components and steps set forth in these embodiments do not limit the scope of the invention. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.
[0020] The HPLC testing process involved in this invention includes: The chromatographic conditions involved in HPLC are shown below: Liquid chromatography system: Agilent LC system; Column: ZORBAX RR Eclipse Plus C18, 95A, 4.6 x 150 mm, 3.5 μm; Column temperature: 25℃; Autosampler temperature: 25℃; Injection volume: 5 μL; Mobile phase: (Aqueous phase: 0.1% formic acid aqueous solution, Organic phase: 0.1% formic acid in acetonitrile); Flow rate: 0.5 mL / min; Run time: 15 min; Gradients are shown in the table below:
[0021] Automatic syringe needle washing solution (F11): methanol.
[0022] The CT parameter conditions involved in this invention are as follows: Tube voltage: 80kV; Tube current: 5mA; Beam filter: 1.5mm aluminum + 0.1mm copper; Scan angle: 360 degrees; Number of scan projections: 450; Distance from light source to detector (SDD) = 1320mm; Distance from light source to object (SOD) = 770mm; Detector model: Varex PaxScan4343CB; X-ray tube model: Varex G-242; Image reconstruction pixel size: 0.2mm; Sample preparation: The target object was dissolved in water and placed in a 1.5 mL centrifuge tube for CT scanning.
[0023] Additionally, the structural formula of contrast agent YJY-79-1 is as follows: The structural formula of the contrast agent with the code YJY-86-2 is as follows: .
[0024] The following specific preparation examples will further explain and illustrate the small molecule contrast agent and its preparation method provided by the present invention.
[0025] The corresponding synthesis route is shown below: Specifically: first step
[0026] Procedure: Compound 1 (1.00 g, 1.0 eq) was dissolved in DMF (20 mL). HATU (1.50 g, 1.5 eq) and DIPEA (735 µL, 1.5 eq) were added to the solution at room temperature. Finally, Compound 2 (3.80 g, 2.0 eq) was added, and the solution was heated to 50 °C and stirred for 1 hour. Then, HATU (1.50 g, 1.5 eq) and DIPEA (735 µL, 1.5 eq) were added again while stirring at 50 °C, and the solution was stirred at 50 °C for another 1 hour.
[0027] Detection: After LCMS showed that most of the samples were products, post-processing was performed.
[0028] Post-processing: The reaction solution was poured into 150 mL of water to obtain a white solid suspension. After filtration and drying, 3.70 g of off-white crude solid 3 was obtained.
[0029] LCMS (ESI): m / z Calcd forC 48 H 52 I6N7O 16 [M+H] + :1743.7, found:1744.1. Step 2
[0030] Procedure: Compound 3 (3.70 g) was dissolved in DMF / piperidine (20%) (40 mL) and reacted at room temperature for 0.5 h.
[0031] Detection: LCMS showed the presence of a main product peak.
[0032] Post-processing: The reaction solution was added to 500 mL of EA to precipitate a light yellow solid. After filtration, 2.70 g of crude light yellow solid product 4 was obtained.
[0033] LCMS (ESI): m / z Calcd for C 33 H 42 I6N7O 14 [M+H] + :1521.7, found:1522.2. Step 3
[0034] Procedure: Compound 4a (315 mg, 1.1 eq) was dissolved in DMF (20 mL), and HATU (934 mg, 1.5 eq) and DIPEA (450 µL, 1.5 eq) were added to the solution at room temperature. Finally, compound 4 (2.70 g, 1.0 eq) was added and the mixture was reacted overnight at room temperature.
[0035] Detection: LCMS showed that the reaction was complete.
[0036] Post-processing: Add 250 mL of ethyl acetate to the reaction solution to precipitate a white solid. Filter the solution, then add 200 mL of water to the solid and stir until it becomes viscous. Filter off the water, redissolve the viscous solid in methanol, evaporate to dryness, and then purify by silica gel column chromatography (EA / MeOH = 10 / 1~8 / 1) to obtain product 5 (1.2 g, crude) as a yellow solid.
[0037] LCMS (ESI): m / z Calcd for C 41 H 54 I6N7O 17 [M+H] + :1677.7, found:1678.3. Step 4
[0038] Procedure: Compound 5 (1.20 g, 1.0 eq) was dissolved in DCM / TFA = 3 / 1 (15 mL) under ice bath conditions, brought to room temperature, and stirred at room temperature for 2 h.
[0039] Detection: LCMS showed that the reaction was complete.
[0040] Post-processing and purification: 250 mL of ethyl acetate was added to the reaction system, and a large amount of off-white solid precipitated. The solid was filtered and then purified by silica gel column chromatography (DCM / MeOH=10 / 1~3 / 1) to obtain product 6 (680 mg, crude).
[0041] LCMS (ESI): m / z Calcd for C 37 H 46 I6N7O 17 [M+H] + :1621.7, found:1622.4 Step 5
[0042] Procedure: Compound 6 (680 mg, 1.0 eq) was dissolved in DMF (10 mL), and HATU (238 mg, 1.5 eq) and DIPEA (115 µL, 1.5 eq) were added to it at room temperature. Finally, compound 7 (244 mg, 1.1 eq) was added and the mixture was reacted at room temperature for 3 h.
[0043] Detection: LCMS showed that the reaction was complete.
[0044] Post-processing: 250 mL of ethyl acetate was added to the reaction solution to precipitate a white solid. The solid was filtered, dissolved in DMF, and purified by pre-TLC (DCM / MeOH=2 / 1). The obtained solid was then purified by pre-HPLC to obtain 6-H-6 (24.5 mg) as a white solid.
[0045] LCMS (ESI): m / z Calcd for C 57 H 81 I6N 10 O 30 [M+H] + :2146.9, found:1074.5 ((M+2) / 2). 1 HNMR(400 MHz, D2O) δ 8.54 (d,J = 4.1 Hz, 2H), 8.43 (s, 1H), 8.26 (d,J= 8.5 Hz, 2H), 8.11 (s, 1H), 7.41 (dd,J = 8.4, 4.5 Hz, 2H), 4.27 (d,J = 27.2Hz, 6H), 4.01 (s, 3H), 3.87 – 3.29 (m, 50H), 3.01 (d,J = 10.8 Hz, 1H), 2.77(d,J = 10.3 Hz, 2H), 2.58 (s, 8H), 2.24 (d,J = 20.4 Hz, 2H). Experimental Example 1 The small molecule contrast agent (6-H-6) prepared in this invention was formulated into a solution with a concentration of 13.80 mmol / mL and subjected to CT testing. The results were compared with those of iohexol, as shown in the table below:
[0046] Experimental Example 2 The CT results after diluting all the above samples by half with water, resulting in a sample concentration of 6.90 mmol / mL, are as follows:
[0047] Depend on Figures 1 to 2 It is evident that 6-H-6 is brighter and has a larger mean value than iohexol, therefore, at the same concentration, 6-H-6 has a stronger imaging ability.
[0048] Experimental Example 3 Stability comparison of contrast agents 6-H-6 and YJY-86-2: Among them, Stability test of contrast agent 6-H-6 in water (40 hours) HPLC comparison table:
[0049] Stability test of contrast agent YJY-86-2 in water (40 hours) HPLC comparison table:
[0050] A comparison of the HPLC chromatograms and tables over 40 hours shows that 6-H-6 has better stability than YJY-86-2.
[0051] Experiment Example 4 Comparison of CT test data for contrast agents 6-H-6, YJY-79-1, and YJY-80-1: Comparison of CT test results for contrast agents 6-H-6, YJY-79-1, and YJY-80-1 at a sample concentration of 13.80 mmol / mL:
[0052] The comparison of the data in the table shows that the mean value of contrast agent 6-H-6 is larger, meaning that at the same concentration, 6-H-6 has a stronger and brighter contrast brightness than YJY-79-1 and YJY-80-1.
[0053] In summary, this invention provides a small molecule contrast agent and its preparation method. Its structure is shown below: .
[0054] The small-molecule contrast agent provided by this invention constructs a symmetrical backbone based on the coupling of iohexol dimer and glycosyl groups. This design enables it to surpass traditional small-molecule contrast agents in imaging performance and stability. Compared with the clinically classic iohexol, this molecule integrates two iohexol backbones and glycosyl targeting groups, increasing the number of iodine atoms per molecule to six. This ultra-high iodine content directly translates into inherent contrast brightness. Experimental data conclusively confirm that, at equimolar concentrations, its CT value is significantly higher than that of iohexol and other single-ring contrast agents with a similar targeting design, such as YJY-79-1, meaning that clearer imaging results can be obtained at the same dosage. More importantly, this symmetrical rigid backbone endows the molecule with excellent chemical stability. As the stability test results show, its purity remains 100% after being placed in water for 40 hours, far superior to the control compound YJY-86-2 (purity decreased to 82.4%). This ensures the reliability of the product during storage and use and reduces the potential risks from degradation products. In summary, this unique "targeted dual-core" structural feature gives the contrast agent the dual advantages of high-intensity imaging signal and high self-stability, laying a solid material foundation for achieving the clinical goals of lower dosage, higher image quality, and better safety.
[0055] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A small molecule contrast agent, the structure of which is shown below: 。 2. A method for preparing the small molecule contrast agent according to claim 1, characterized in that, include: compound Dissolves with HATU, DIPEA, and other compounds. The mixture was heated and stirred to obtain the compound. ; The compound The compound was obtained by dissolving it in a mixed solution of piperidine and N,N-dimethylformamide and reacting it at room temperature. ； compound After dissolution, it is mixed with HATU, DIPEA and compound 4, and left overnight to obtain compound 4. ; Compound 5 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, and reacted at a preset temperature to obtain compound 5. ; After dissolving compound 6, it was combined with HATU, DIPEA, and other compounds. The mixture is then used to obtain the small molecule contrast agent.
3. The method for preparing the small molecule contrast agent according to claim 2, characterized in that, The equivalent ratio of compound 1 to compound 2 is 1:2-3; the reaction temperature is 20℃-55℃.
4. The method for preparing the small molecule contrast agent according to claim 2, characterized in that, The equivalent ratio of compound 4 to compound 4a is 1:1-1.
5.
5. The method for preparing the small molecule contrast agent according to claim 4, characterized in that, The equivalent ratio of compound 6 to compound 7 is 1:1-1.
5.
6. The method for preparing the small molecule contrast agent according to claim 2, characterized in that, The preset temperature is 0℃-24℃.
7. The method for preparing the small molecule contrast agent according to claim 2, characterized in that, The volume ratio of the dichloromethane to the trifluoroacetic acid is 4-2:
1.
8. The application of the small molecule contrast agent according to claim 1 in targeted contrast imaging.