Targeted near-infrared fluorescent compound, preparation method therefor, and use thereof

Abstract

Provided are a targeted near-infrared fluorescent compound, a preparation method therefor, and use thereof, relating to the technical field of near-infrared fluorescent molecules. The targeted near-infrared fluorescent compound has a structure represented by formula I below. By using an organic total synthesis method, a S0456 near-infrared small molecule is modified on a COX-2 inhibitor to obtain the targeted near-infrared fluorescent compound represented by formula I. The targeted near-infrared fluorescent compound has a good active targeting effect when identifying COX-2-overexpressing liver tumors; moreover, the targeted near-infrared fluorescent compound retains the water solubility of a dye and specificity for tumor cells, and has the advantages of good water solubility, high fluorescence quantum yield, and the like.

Description

A targeted near-infrared fluorescent compound, its preparation method and application

[0001] Cross-references to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 2024114352743, filed on October 15, 2024, entitled “A Targeted Near-Infrared Fluorescent Compound and Its Preparation Method and Application,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of near-infrared fluorescent molecular technology, and in particular to a targeted near-infrared fluorescent compound, its preparation method, and its application. Background Technology

[0004] Cancer remains the leading cause of death worldwide. Cancer-related deaths can be reduced by 30% in patients diagnosed and treated early, highlighting the importance of developing new strategies for early diagnosis. Consequently, significant efforts have been made over the past decade to develop imaging technologies for early cancer diagnosis. Various methods have been used for cancer imaging, including single-photon emission computed tomography (SPECT) and positron emission tomography (PET), computed tomography (CT), radionuclide imaging using single-photon and positron emission tomography, magnetic resonance imaging (MRI), ultrasound (US), and optical imaging. However, conventional examination techniques cannot provide sufficient contrast to sensitively and reliably identify early-stage tumors.

[0005] To address this issue, fluorescence imaging methods have attracted widespread attention due to their high selectivity and sensitivity, relatively low cost, and non-invasiveness. Fluorescent probes have been used for early diagnosis by detecting enzymes highly expressed in different types of cancer. Clinical results indicate that COX-2 is an overexpressed enzyme in tumors at all stages, while it is not expressed or is weakly expressed in normal tissues. Therefore, detecting and imaging COX-2 with specific fluorescent probes can provide valuable information for early cancer diagnosis. Thus, COX-2 fluorescent probes have become a promising tool for detecting early-stage cancer. In recent years, many COX-2 fluorescent probes have been developed and proven to measure COX-2 expression levels in cells and early-stage tumor tissues. Traditionally, most fluorescent probes are synthesized by conjugating large molecular fluorophores to target drugs via appropriate flexible linkers.

[0006] In view of this, this disclosure is hereby made. Summary of the Invention

[0007] The purpose of this disclosure includes providing a targeted near-infrared fluorescent compound, its preparation method, and its applications. The targeted near-infrared fluorescent compound provided in this disclosure is a near-infrared fluorescent molecule IMCS obtained by linking the near-infrared fluorescent molecule S0456 to a COX2 inhibitor. It can specifically target and be used to identify COX-2 overexpressing tumors, and has advantages such as good water solubility and high fluorescence quantum yield.

[0008] To achieve the above-mentioned objectives of this disclosure, the following technical solutions may be adopted:

[0009] In a first aspect, this disclosure provides a targeted near-infrared fluorescent compound having the structure shown in Formula I:

[0010] In this disclosure, a novel near-infrared fluorescent probe, indomethacin-S0456 probe (the near-infrared fluorescent compound represented by Formula I, hereinafter referred to as IMCS), with the ability to target COX-2 was designed and synthesized.

[0011] In a second aspect, this disclosure provides a method for preparing a targeted near-infrared fluorescent compound as described in the first aspect, the method comprising the following steps:

[0012] (1) Compound SO456 reacts with p-hydroxyphenylpropionate to give compound A;

[0013] The structural formula of compound A is shown below:

[0014] (2) After the reaction of indomethacin and N-Boc-ethylenediamine, deprotection treatment is performed to obtain compound B;

[0015] The structural formula of compound B is shown below:

[0016] (3) Compound A and compound B react to obtain the targeted near-infrared fluorescent compound shown in Formula I.

[0017] In an optional embodiment, in step (1), the molar ratio of compound SO456 and p-hydroxyphenylpropionate is 1:(2-4).

[0018] In an optional embodiment, in step (1), p-hydroxyphenylpropionate includes sodium p-hydroxyphenylpropionate.

[0019] In an optional embodiment, in step (1), the reaction is carried out in a solvent, including dimethyl sulfoxide.

[0020] In an optional embodiment, in step (1), the reaction is carried out under a protective gas atmosphere, including nitrogen.

[0021] In an optional embodiment, in step (1), the reaction temperature is 60-70°C and the reaction time is 5-7 hours.

[0022] In an optional implementation, step (1) further includes a post-processing step after the reaction is complete:

[0023] The reaction solution obtained after the reaction in step (1) was added dropwise to a mixture of ethyl acetate and ethanol, filtered and dried to obtain compound A.

[0024] In an optional embodiment, the volume ratio of ethyl acetate to ethanol in the mixture is 1:(0.5-2).

[0025] In an optional embodiment, in step (2), the molar ratio of indomethacin to N-Boc-ethylenediamine is 1:(1 to 1.5).

[0026] In an optional embodiment, in step (2), the reaction is carried out in the presence of a condensing agent, including dipyrrolidinyl (N-succinyliminooxy) caronium hexafluorophosphate.

[0027] In an optional embodiment, in step (2), the molar ratio of indomethacin and dipyrrolidinyl (N-succinyliminooxy)carbomony hexafluorophosphate is 1:(1.2-2).

[0028] In an optional embodiment, in step (2), the reaction is carried out in the presence of a base selected from N,N-diisopropylethylamine.

[0029] In an optional embodiment, in step (2), the molar ratio of indomethacin to the base is 1:(0.5-5).

[0030] In an optional embodiment, in step (2), the reaction is carried out in a solvent, including dichloromethane.

[0031] In an optional embodiment, in step (2), the reaction temperature is 30-40°C and the reaction time is 1-3 hours.

[0032] In an optional implementation, step (2) of the deprotection process may include the following steps:

[0033] Trifluoroacetic acid was added to the reaction solution obtained after the reaction of indomethacin and N-Boc-ethylenediamine, and the mixture was stirred and concentrated to obtain compound B.

[0034] In an optional embodiment, the molar ratio of N-Boc-ethylenediamine to trifluoroacetic acid is 1:(1-5).

[0035] In an optional embodiment, the stirring temperature is 20–40°C, and the stirring time is 1–3 hours.

[0036] In an optional embodiment, in step (3), the molar ratio of compound A to compound B is 1:(0.5 to 2).

[0037] In an optional embodiment, in step (3), the reaction is carried out in the presence of a condensing agent, including dipyrrolidinyl (N-succinyliminooxy) caronium hexafluorophosphate.

[0038] In an optional embodiment, in step (3), the molar ratio of compound A to dipyrrolidinyl (N-succinyliminooxy)carbomon hexafluorophosphate is 1:(1.2-2).

[0039] In an optional embodiment, in step (3), the molar ratio of compound A to base is 1:(0.5-5).

[0040] In an optional embodiment, in step (3), the reaction is carried out in a solvent, including dimethyl sulfoxide.

[0041] In an optional embodiment, in step (3), the reaction temperature is 30-40°C and the reaction time is 18-30h.

[0042] In an optional implementation, step (3) further includes a post-processing step after the reaction is complete:

[0043] The reaction solution obtained after the reaction in step (3) is added dropwise to an acetone solution, filtered and dried to obtain the targeted near-infrared fluorescent compound shown in Formula I.

[0044] Thirdly, this disclosure provides the use of a targeted near-infrared fluorescent compound or its racemate, stereoisomer, or pharmaceutically acceptable salt, as described in the first aspect, in the preparation of a reagent for tumor imaging.

[0045] In an optional implementation, the tumor includes any one of liver cancer, pancreatic cancer, colon cancer, gastric cancer, breast cancer, or head and neck cancer.

[0046] Fourthly, this disclosure provides the use of a targeted near-infrared fluorescent compound or its racemate, stereoisomer, or pharmaceutically acceptable salt, as described in the first aspect, in the preparation of a reagent for identifying COX-2 overexpressing tumors.

[0047] Compared to the prior art, the beneficial effects of this disclosure include:

[0048] (1) This disclosure utilizes an organic total synthesis method to synthesize IMCS, which exhibits higher selectivity for COX-2 when bound to the fluorescent dye SO456. It can be rapidly cleared in normal tissues, thereby quickly achieving a tumor background signal ratio (TBR>1.5) that meets clinical needs, and has good active targeting effects in identifying COX-2 overexpressing tumors.

[0049] (2) The targeted near-infrared fluorescent compound IMCS provided in this disclosure has the advantages of water solubility of dyes and high fluorescence quantum yield. It has great development potential in the fields of near-infrared fluorescence-guided tumor surgery and medical cell labeling. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the specific embodiments of this disclosure or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 shows the IMCS fluorescent molecules. 1 HNMR spectrum;

[0052] Figure 2 is the fluorescence molecular mass spectrum of IMCS;

[0053] Figure 3 is the IMCS fluorescent molecular liquid chromatography chromatogram;

[0054] Figure 4 shows the fluorescence properties of the IIIMCS fluorescent molecules;

[0055] Figure 5 shows the specific targeting effects of different doses of IMCS on liver tumors;

[0056] Figure 6 shows the trend of TBR changes under different doses of IMCS;

[0057] Figure 7 shows the distribution of IMCS fluorescence signals in various organs. Detailed Implementation

[0058] Unless otherwise defined herein, the scientific and technical terms used in this disclosure shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any event of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0059] It should be noted that specific details are set forth in the following description to provide a full understanding of this disclosure. However, this disclosure can be implemented in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this disclosure. Therefore, this disclosure is not limited to the specific embodiments disclosed below.

[0060] The technical solutions of this disclosure will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this disclosure, not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0061] In a first aspect, this disclosure provides a targeted near-infrared fluorescent compound having the structure shown in Formula I:

[0062] In this disclosure, a novel near-infrared fluorescent probe, indomethacin-S0456 probe (IMCS), with COX-2 targeting capability was designed and synthesized. Using indomethacin as the recognition group, and linking it to SO456 via ethylenediamine, a COX-2 targeting fluorescent probe (the targeting near-infrared fluorescent compound shown in Formula I, hereinafter referred to as IMCS) with excitation (775 nm) and emission (797 nm) was constructed, exhibiting higher selectivity for COX-2. The obtained IMCS can be rapidly cleared in normal tissues, thereby quickly achieving a tumor background signal ratio (TBR>1.5) that meets clinical requirements. It demonstrates good active targeting in identifying COX-2 overexpressing tumors, further expanding the application value of the drug for surgical navigation and tumor resection. Furthermore, IMCS also possesses the advantages of dye water solubility and high fluorescence quantum yield.

[0063] Indomethacin, a nonsteroidal anti-inflammatory drug (NSAID), exerts its selective diagnostic and therapeutic effects on tumors by targeting the biosynthesis of COX-derived prostaglandins (PGs). It becomes even more selective when bound to fluorescent dyes. Indomethacin combined with fluorescent tracers has shown a significant targeting ability against COX2-overexpressing cancer cells rather than normal cells. This has certain research value and can be used for the development of specific targeted fluorescent probes.

[0064] In a second aspect, this disclosure provides a method for preparing a targeted near-infrared fluorescent compound as described in the first aspect, the method comprising the following steps:

[0065] (1) Compound SO456 reacts with p-hydroxyphenylpropionate to give compound A;

[0066] The structural formula of compound A is shown below:

[0067] (2) After the reaction of indomethacin and N-Boc-ethylenediamine, deprotection treatment is performed to obtain compound B;

[0068] The structural formula of compound B is shown below:

[0069] (3) Compound A and compound B react to obtain the targeted near-infrared fluorescent compound shown in Formula I.

[0070] In an optional embodiment, the method for preparing the targeted near-infrared fluorescent compound includes the following steps:

[0071] (1) Compound S0456 reacts with p-hydroxyphenylpropionate to give compound A; the reaction formula is shown below:

[0072] (2) After the reaction of indomethacin and N-Boc-ethylenediamine, deprotection treatment was performed to obtain compound B; the structural formula of compound B is shown below:

[0073] (3) Compound A and compound B react to obtain the targeted near-infrared fluorescent compound shown in Formula I; wherein the reaction formula is as follows:

[0074] In this disclosure, a targeted near-infrared fluorescent compound (IMCS) of formula I, modified with the COX-2 inhibitor indomethacin, was synthesized using organic total synthesis. IMCS demonstrates significant targeting ability in identifying COX2-overexpressing cancer cells rather than normal cells. This targeted near-infrared fluorescent compound of formula I retains the water solubility and specificity of the dye for tumor cells. As a tracer, it possesses advantages such as good water solubility and high fluorescence quantum yield, showing great potential for development in fields such as fluorescence-guided tumor surgery and medical cell labeling.

[0075] In an optional embodiment, in step (1), the molar ratio of compound SO456 and p-hydroxyphenylpropionate can be 1:(2-4), for example, it can be 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:3, 1:3.2, 1:3.4, 1:3.6, 1:3.8 or 1:4, or other values ​​within the range of 1:(2-4).

[0076] In an optional embodiment, in step (1), p-hydroxyphenylpropionate includes sodium p-hydroxyphenylpropionate.

[0077] In an optional embodiment, in step (1), the reaction is carried out in a solvent.

[0078] In an optional embodiment, in step (1), the solvent includes dimethyl sulfoxide.

[0079] In an optional implementation, in step (1), the reaction is carried out under a protective gas atmosphere.

[0080] In an optional implementation, the protective gas in step (1) includes nitrogen.

[0081] In an optional embodiment, in step (1), the reaction temperature can be 60 to 70°C, for example, 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, or other values ​​within the range of 60 to 70°C.

[0082] In an optional implementation, the reaction time in step (1) can be 5 to 7 hours, for example, 5 hours, 5.2 hours, 5.4 hours, 5.6 hours, 5.8 hours, 6 hours, 6.2 hours, 6.4 hours, 6.6 hours, 6.8 hours or 7 hours, or other values ​​within the range of 5 to 7 hours.

[0083] In an optional implementation, step (1) may further include a post-processing step after the reaction is complete:

[0084] The reaction solution obtained after the reaction in step (1) was added dropwise to a mixture of ethyl acetate and ethanol, filtered and dried to obtain compound A.

[0085] In an optional embodiment, the volume ratio of ethyl acetate to ethanol in the mixture can be 1:(0.5 to 2), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.4, 1:1.6, 1:1.8 or 1:2, or other values ​​within the range of 1:(0.5 to 2).

[0086] In an optional implementation, in step (2), the molar ratio of indomethacin and N-Boc-ethylenediamine can be 1:(1 to 1.5), for example, it can be 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1:1.5, or other values ​​within the range of 1:(1 to 1.5).

[0087] In an optional embodiment, in step (2), the reaction is carried out in the presence of a condensing agent, which may include dipyrrolidinyl (N-succinyliminooxy) caronium hexafluorophosphate.

[0088] In an optional embodiment, in step (2), the molar ratio of indomethacin and dipyrrolidinyl (N-succinyliminooxy)carbomony hexafluorophosphate can be 1:(1.2-2), for example, it can be 1:1.2, 1:1.25, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2, or other values ​​within the range of 1:(1.2-2).

[0089] In an optional embodiment, in step (2), the reaction is carried out in the presence of a base, which includes N,N-diisopropylethylamine.

[0090] In an optional implementation, in step (2), the molar ratio of indomethacin to the base can be 1:(0.5 to 5), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, or other values ​​within the range of 1:(0.5 to 5).

[0091] In an optional embodiment, in step (2), the reaction is carried out in a solvent.

[0092] In an optional embodiment, in step (2), the solvent includes dichloromethane.

[0093] In an optional embodiment, the reaction temperature in step (2) can be 30 to 40°C, for example, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C, or other values ​​within the range of 30 to 40°C.

[0094] In an optional implementation, the reaction time in step (2) can be 1 to 3 hours, for example, 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours, or other values ​​within the range of 1 to 3 hours.

[0095] In an optional implementation, step (2) of the deprotection process may include the following steps:

[0096] Trifluoroacetic acid was added to the reaction solution obtained after the reaction of indomethacin and N-Boc-ethylenediamine, and the mixture was stirred and concentrated to obtain compound B.

[0097] In an optional embodiment, in step (2), the molar ratio of N-Boc-ethylenediamine and trifluoroacetic acid can be 1:(1 to 5), for example, it can be 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, or other values ​​within the range of 1:(1 to 5).

[0098] In an optional embodiment, in step (2), the stirring temperature can be 20 to 40°C, for example, 20°C, 22°C, 24°C, 26°C, 28°C, 30°C, 32°C, 34°C, 36°C, 38°C or 40°C, or other values ​​within the range of 20 to 40°C.

[0099] In an optional implementation, the stirring time in step (2) can be 1 to 3 hours, for example, 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours or 3 hours, or other values ​​within the range of 1 to 3 hours.

[0100] In an optional embodiment, in step (3), the molar ratio of compound A and compound B can be 1:(0.5 to 2), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.4, 1:1.6, 1:1.8 or 1:2, or other values ​​within the range of 1:(0.5 to 2).

[0101] In an optional embodiment, in step (3), the reaction is carried out in the presence of a condensing agent.

[0102] In an optional embodiment, in step (3), the condensing agent includes dipyrrolidinyl (N-succinyliminooxy) caronium hexafluorophosphate.

[0103] In an optional embodiment, in step (3), the molar ratio of compound A and dipyrrolidinyl (N-succiniminooxy)carbomony hexafluorophosphate can be 1:(1.2-2), for example, 1:1.2, 1:1.25, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9 or 1:2, or other values ​​within the range of 1:(1.2-2).

[0104] In an optional embodiment, in step (3), the reaction is carried out in the presence of a base.

[0105] In an optional embodiment, in step (3), the base includes N,N-diisopropylethylamine.

[0106] In an optional embodiment, in step (3), the molar ratio of compound A to the base can be 1:(0.5 to 5), for example, it can be 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5 or 1:5, or other values ​​within the range of 1:(0.5 to 5).

[0107] In an optional embodiment, in step (3), the reaction is carried out in a solvent, including dimethyl sulfoxide.

[0108] In an optional embodiment, the reaction temperature in step (3) can be 30 to 40°C, for example, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C, or other values ​​within the range of 30 to 40°C.

[0109] In an optional implementation, the reaction time in step (3) can be 18 to 30 hours, for example, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours or 30 hours, or other values ​​within the range of 18 to 30 hours.

[0110] In an optional implementation, step (3) may further include a post-processing step after the reaction is complete:

[0111] The reaction solution obtained after the reaction in step (3) is added dropwise to an acetone solution, filtered and dried to obtain the targeted near-infrared fluorescent compound shown in Formula I.

[0112] Thirdly, this disclosure provides the use of a targeted near-infrared fluorescent compound or its racemate, stereoisomer, or pharmaceutically acceptable salt, as described in the first aspect, in the preparation of a reagent for tumor imaging.

[0113] In some alternative implementations, the tumor may include any one of liver cancer, pancreatic cancer, colon cancer, gastric cancer, breast cancer, or head and neck cancer.

[0114] Fourthly, this disclosure provides the use of a targeted near-infrared fluorescent compound or its racemate, stereoisomer, or pharmaceutically acceptable salt, as described in the first aspect, in the preparation of a reagent for identifying COX-2 overexpressing tumors.

[0115] In an optional implementation, the application specifically involves: establishing a tumor imaging model using a targeted near-infrared fluorescent compound, such as the one described in the first aspect, or its racemic, stereoisomer, or pharmaceutically acceptable salt, and using an intraoperative fluorescence navigation device to diagnose the tumor's effectiveness.

[0116] In an optional embodiment, this disclosure provides a liver cancer tumor imaging model and a method for establishing the same, which may include the following steps: inoculating a human liver cancer cell line with COX-2 high expression into the back of a mouse, and injecting the targeted near-infrared fluorescent compound (IMCS) of this disclosure via tail vein injection.

[0117] It should be noted that after the above-mentioned liver tumor imaging model is established, intraoperative fluorescence navigation equipment can be used to diagnose liver tumors using small molecules; and liver tumors can be removed during surgery, and pathological sections can be used to determine whether IMCS can specifically target liver tumors.

[0118]

Terminology Explanation

[0119] As mentioned in this disclosure, the term "pharmaceutically acceptable salt" means that the salt is not only physiologically acceptable to the subject, but also refers to a synthetic substance that has pharmaceutical value, such as a salt formed as an intermediate in the chiral resolution process, although such intermediate salt cannot be given directly to the subject, but can play a role in obtaining the end product of this disclosure.

[0120] As mentioned in this disclosure, a pharmaceutically acceptable salt of the compound represented by Formula I is a salt formed with a base or alkali metal. Acids that form pharmaceutically acceptable salts with the compound represented by Formula I include inorganic acids and organic acids. More specifically, alkali metals that form pharmaceutically acceptable salts with the compound represented by Formula I include, but are not limited to, lithium, sodium, potassium, magnesium, calcium, aluminum, zinc, etc.; bases that form pharmaceutically acceptable salts with the compound represented by Formula I include, but are not limited to, choline, diethanolamine, morpholine, etc.

[0121] The present disclosure will be further illustrated below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0122] Example 1

[0123] This embodiment provides a targeted near-infrared fluorescent compound IMCS, having the structure shown in Formula I:

[0124] The synthetic route for the targeted near-infrared fluorescent compound IMCS is shown below:

[0125] The preparation method of the targeted near-infrared fluorescent compound IMCS specifically includes the following steps:

[0126] (a) Preparation of compound A:

[0127] SO456 (888 mg, 1 mmol) was dissolved in 10 mL of DMSO and stirred until completely dissolved. Sodium p-hydroxyphenylpropionate (424 mg, 2 mmol) was added to the flask, and the mixture was reacted at 65 °C for 6 h under nitrogen protection. The resulting solution was then added dropwise to a mixture of ethyl acetate and ethanol (V... 乙酸乙酯 :V 乙醇 =1:1), producing a dark green precipitate, which was filtered and dried under vacuum to give 1.05 g of solid (i.e., compound A), with a yield of 95%.

[0128] (b) Preparation of compound B:

[0129] Indomethacin (0.357 g, 1 mmol) was placed in a round-bottom flask and dissolved in 20 mL of dichloromethane. Then, dipyrrolidinyl (N-succiniminooxy)carbomony hexafluorophosphate (483 mg, 1.176 mmol), N-Boc-ethylenediamine (320 mg, 2 mmol), and DIEA (151 mg, 1.176 mmol) were added sequentially. The mixture was stirred at 37 °C for 2 h. After the reaction was completed, 2 mL of trifluoroacetic acid was added to the reaction system, and the mixture was stirred at 37 °C for 2 h. The solution was then evaporated to dryness to obtain compound B, yielding 0.3 g (i.e., compound B).

[0130] (c) Preparation of compound IMCS:

[0131] Compound A (1.01 g, 1 mmol) was placed in a round-bottom flask and dissolved in 20 mL of DMSO. Dipyrrolidinyl (N-succiniminooxy)carbomony hexafluorophosphate (483 mg, 1.176 mmol), DIEA (258 mg, 2 mmol), and compound B (0.8 g, 2 mmol) were added sequentially. The mixture was stirred at 37 °C for 24 h, and the precipitate was collected in acetone solution. The precipitate was filtered, dried under vacuum, and the product was purified by preparative liquid chromatography to obtain the targeted near-infrared fluorescent compound IMCS represented by formula I.

[0132] The structure was characterized by 1H NMR, HPLC, and mass spectrometry, and the structural determination results are as follows:

[0133] As shown in Figure 1, 1HNMR (400MHz, DMSO-d6) δ: 8.06,7.82,7.78,7.71,7.69,7.63,7.63,7.62,7.61,7.61,7.59,7.59,7.33,7.31,7.20,7.18,7.11,7.10,7.0 5,7.03,6.94,6.92,6.69,6.68,6.67,6.66,6.23,6.20,4.11,3.83,3 .73,3.49,3.03,2.72,2.71,2.69,2.67,2.20,1.93,1.76,1.73,1.25.

[0134] As shown in Figure 2, LCMS(ESI): m / z: Chemical Formula: C 68 H 76 ClN5O 17 S4, [M-3H]found 465.15, [M-2H]found 698.65.

[0135] As shown in Figure 3, the purity of the targeted near-infrared fluorescent compound IMCS is 96.66%.

[0136] As shown in Figure 4, the target near-infrared fluorescent compound IMCS has a maximum excitation wavelength Ex max = 775 nm and a maximum fluorescence emission wavelength Em max = 797 nm, indicating that the molecule is a near-infrared fluorescent probe.

[0137] Application Example 1

[0138] This application example demonstrates the use of IMCS near-infrared fluorescent molecules in the specific identification of liver cancer.

[0139] A liver cancer model was constructed using the HepG2 cell line: Human liver cancer cells derived from the COX-2 high-expressing HepG2 cell line were seeded into the back of Balb / c nude cells, and 10 nmol of IMCS molecules were injected into each cell via the tail vein. Intraoperative fluorescence navigation was used to diagnose the liver cancer effect of the small molecule. The liver cancer cells were removed during surgery, and pathological sections were used to determine whether IMCS specifically targeted liver tumors.

[0140] The test results are shown in Figures 5, 6, and 7:

[0141] As shown in Figures 5 and 6, after injection of 1, 5, 10, 50, and 100 nmol IMCS, at 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, 48 h, and 72 h, the mice showed high fluorescence signals only in the tumor area on their backs. In the surrounding normal tissue, the IMCS was gradually metabolized, and the fluorescence intensity decayed faster than in the tumor. This not only met the clinical imaging requirements for transluminal imaging (TBR) after 1 h but also provided a wide imaging window. This demonstrates that IMCS has good specificity in identifying COX2-overexpressing liver tumors.

[0142] Figure 7 shows the fluorescence signal distribution of the isolated organs over 24 hours. At each time point, the fluorescence intensity of the tumor tissue was significantly higher than that of other tissues. This indicates that IMCS can specifically accumulate in tumors.

[0143] In summary, the purpose of this disclosure is to provide a near-infrared fluorescent probe, its preparation method, and its applications. This probe can actively target COX2, is rapidly cleared in normal tissues, and remains for a long time in tumor sites, thereby achieving in vivo diagnostic capabilities. It exhibits excellent active targeting in the identification of liver cancer. This near-infrared fluorescent dye retains the dye's water solubility and specificity for tumor cells. This tracer has advantages such as good water solubility and high fluorescence quantum yield, and has great potential for development in near-infrared fluorescence-guided tumor surgery and medical cell labeling.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure. Industrial applicability

[0145] The targeted near-infrared fluorescent compound disclosed herein has a good active targeting effect in identifying COX-2 overexpressing liver tumors; and the targeted near-infrared fluorescent compound retains the water solubility of the dye and the specificity to tumor cells, and has the advantages of good water solubility and high fluorescence quantum yield.

Claims

1. A near-infrared fluorescent targeting compound, characterized in that, The targeting near-infrared fluorescent compound has a structure shown in the following formula I:

2. A method of preparing a targeted near-infrared fluorescent compound according to claim 1, characterized in that, The preparation method includes the following steps: (1) Compound SO456 reacts with p-hydroxyphenylpropionate to give compound A; The structural formula of the compound A is as follows: (2) After the reaction of indomethacin and N-Boc-ethylenediamine, deprotection treatment is performed to obtain compound B; The structural formula of the compound B is as follows: (3) Compound A and compound B react to obtain the targeted near-infrared fluorescent compound shown in Formula I.

3. The method for preparing the targeted near-infrared fluorescent compound according to claim 2, characterized in that, In step (1), the molar ratio of compound SO456 and p-hydroxyphenylpropionate is 1:(2-4).

4. The method of producing a targeted near-infrared fluorescent compound according to claim 2 or 3, characterized by, In step (1), the p-hydroxyphenylpropionate includes sodium p-hydroxyphenylpropionate.

5. The method of preparing a targeted near-infrared fluorescent compound according to any one of claims 2 to 4, characterized in that, In step (1), the reaction is carried out in a solvent, which includes dimethyl sulfoxide.

6. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 5, characterized in that, In step (1), the reaction is carried out under a protective gas atmosphere, the protective gas including nitrogen.

7. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 6, characterized in that, In step (1), the reaction temperature is 60-70°C and the reaction time is 5-7 hours.

8. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 7, characterized in that, In step (1), after the reaction is completed, a post-processing step is also included: The reaction solution obtained after the reaction in step (1) was added dropwise to a mixture of ethyl acetate and ethanol, and after filtration and drying, compound A was obtained.

9. The method for preparing the targeted near-infrared fluorescent compound according to claim 8, characterized in that, In the mixture, the volume ratio of ethyl acetate to ethanol is 1:(0.5-2).

10. The method of preparing a targeted near-infrared fluorescent compound according to any one of claims 2 to 9, characterized in that, In step (2), the molar ratio of indomethacin and N-Boc-ethylenediamine is 1:(1 to 1.5).

11. The method of preparing a targeted near-infrared fluorescent compound according to any one of claims 2 to 10, characterized in that, In step (2), the reaction is carried out in the presence of a condensing agent, which includes dipyrrolidinyl (N-succinyliminooxy) caronium hexafluorophosphate.

12. The method for preparing the targeted near-infrared fluorescent compound according to claim 11, characterized in that, In step (2), the molar ratio of indomethacin and dipyrrolidinyl (N-succinyliminooxy) caronium hexafluorophosphate is 1:(1.2-2).

13. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 12, characterized in that, In step (2), the reaction is carried out in the presence of a base, which includes N,N-diisopropylethylamine.

14. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 13, characterized in that, In step (2), the molar ratio of indomethacin to the base is 1:(0.5-5).

15. The method of preparing a targeted near-infrared fluorescent compound according to any one of claims 2 to 14, wherein, In step (2), the reaction is carried out in a solvent, including dichloromethane.

16. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 15, characterized in that, In step (2), the reaction temperature is 30-40°C and the reaction time is 1-3 hours.

17. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 16, characterized in that, In step (2), the deprotection process includes the following steps: Trifluoroacetic acid was added to the reaction solution obtained after the reaction of indomethacin and N-Boc-ethylenediamine, and the mixture was stirred and concentrated to obtain compound B.

18. The method for preparing the targeted near-infrared fluorescent compound according to claim 17, characterized in that, The molar ratio of N-Boc-ethylenediamine to trifluoroacetic acid is 1:(1-5).

19. The method for preparing the targeted near-infrared fluorescent compound according to claim 17 or 18, characterized in that, The stirring temperature is 20–40°C, and the stirring time is 1–3 hours.

20. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 19, characterized in that, In step (3), the molar ratio of compound A to compound B is 1:(0.5-2).

21. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 20, characterized in that, In step (3), the reaction is carried out in the presence of a condensing agent, which includes dipyrrolidinyl (N-succinyliminooxy) caronium hexafluorophosphate.

22. The method for preparing the targeted near-infrared fluorescent compound according to claim 21, characterized in that, In step (3), the molar ratio of compound A to dipyrrolidinyl (N-succinyliminooxy)carbomon hexafluorophosphate is 1:(1.2-2).

23. The method of preparing a targeted near infrared fluorescent compound according to any one of claims 2 to 22, wherein, In step (3), the reaction is carried out in the presence of a base, which includes N,N-diisopropylethylamine.

24. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 23, characterized in that, In step (3), the molar ratio of compound A to base is 1:(0.5-5).

25. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 24, characterized in that, In step (3), the reaction is carried out in a solvent, which includes dimethyl sulfoxide.

26. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 25, characterized in that, In step (3), the reaction temperature is 30-40°C and the reaction time is 18-30 h.

27. The method for preparing the targeted near-infrared fluorescent compound according to any one of claims 2 to 26, characterized in that, In step (3), after the reaction is completed, a post-processing step is also included: The reaction solution obtained after the reaction in step (3) is added dropwise to an acetone solution, filtered and dried to obtain the targeted near-infrared fluorescent compound shown in Formula I.

28. The use of a targeted near-infrared fluorescent compound as described in claim 1, or its racemic, stereoisomer, or pharmaceutically acceptable salt thereof, in the preparation of a reagent for tumor imaging.

29. The use according to claim 28, characterized in that, The tumor includes any one of liver cancer, pancreatic cancer, colon cancer, stomach cancer, breast cancer, or head and neck cancer.

30. The use of a targeted near-infrared fluorescent compound as described in claim 1, or a racemic mixture, stereoisomer, or pharmaceutically acceptable salt thereof, in the preparation of a reagent for identifying COX-2 overexpressing tumors.

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