A near-infrared second-region xanthene derivative and its preparation method and biological application

Abstract

The present invention discloses a xanthene derivative having absorption / emission in the near-infrared region II (1000-1700 nm) as shown in formula (1). The absorption / emission wavelength of this type of xanthene derivative is significantly red-shifted, with the longest wavelength exceeding 1200 nm, a high molar extinction coefficient and fluorescence quantum yield, and can effectively generate reactive oxygen species and heat under near-infrared region II laser irradiation. It has excellent photostability, photothermal stability, pH stability and biocompatibility, and can therefore be used as a near-infrared region II fluorescent / photothermal reagent, with good application potential in near-infrared region II fluorescence bioimaging, photodynamic / photothermal anti-tumor / antibacterial.

Description

Technical Field

[0001] The present invention relates to the field of photosensitizers, and more specifically to a near-infrared second region xanthene derivative, a preparation method thereof, and biological applications thereof. Background Art

[0002] The development of fluorescent probes and photodiagnostic agents in the second near-infrared region (NIR-II, 1000-1700nm) is an emerging field in molecular imaging and tumor diagnosis and treatment, and has rapidly become an attractive frontier in the fields of bioimaging and tumor diagnosis and treatment. Compared with traditional bioimaging in the visible light region (400-700nm) and the first near-infrared region (NIR-I, 700-900nm), NIR-II bioimaging has many advantages, including higher spatial resolution, deeper penetration depth, lower optical absorption and scattering of biological tissues, and smaller autofluorescence of biological tissues. Currently, the more common NIR-II fluorophores mainly include organic molecules, rare earth-doped nanoparticles, quantum dots and single-walled carbon nanotubes. From the perspective of clinical application, metal ions may cause long-term toxicity to the human body. Therefore, NIR-II fluorophores based on organic molecules have good potential application value. Organic molecule-based NIR-II fluorophores primarily include polymethyl groups, benzothiadiazoles, and polymers. Benzothiadiazoles and polymers, due to their complex chemical synthesis, low brightness, and molecular structures with multiple aromatic rings coupled together, tend to accumulate and remain in the body, making them difficult to metabolize out of the body. This can lead to long-term biotoxicity and limited prospects for clinical application. A representative polymethyl group is indocyanine green (ICG), which has been approved by the FDA for clinical bioimaging. Although ICG has a high fluorescence quantum yield, its absorption / fluorescence peaks are at 780 / 822 nm, allowing excitation only with an 808 nm laser. Furthermore, the fluorescence tail peak extends beyond 1000 nm, severely limiting its application in deep tissue high-resolution bioimaging.

[0003] Inflammation caused by bacterial and fungal infections is a leading cause of disease and death worldwide. The overuse of antibiotics accelerates the development of bacterial and fungal resistance and may lead to a drug-free future. Furthermore, due to an aging population, environmental pollution, and the emergence of unhealthy behaviors, the incidence of cancer is rapidly increasing worldwide. Photodynamic therapy (PDT) and photothermal therapy (PTT) are emerging noninvasive treatments for bacterial and fungal infections and tumors. PDT utilizes light to excite photosensitizers, which transfer energy to surrounding oxygen molecules. The generated reactive oxygen species react with nearby biomacromolecules, producing phototoxicity and killing bacteria, fungi, and tumor cells. PTT utilizes photothermal agents to convert light energy into heat, inducing apoptosis and necrosis of bacteria, fungi, and tumor cells through local hyperthermia. PDT / PTT, with its precise spatiotemporal control, high specificity, and efficient ability to destroy inflammation or tumors, has become a promising clinical treatment for bacterial and fungal infections and tumors. Furthermore, the combination of PDT / PTT with bioimaging techniques allows for real-time visualization and in situ diagnosis of inflammation and tumors, opening a promising path for the precise diagnosis and effective treatment of inflammation and tumors. Despite these advantages, PDT / PTT still has some inherent defects before clinical translation, such as limited light penetration depth and tumor heat resistance. Currently, most PDT / PTT is based on the near-infrared biological window (NIR-I, 700-1000nm). Due to the physical limitations of light penetrating tissue, PDT / PTT based on the NIR-I region is severely limited in the treatment of deep inflammation and tumor tissue. In order to achieve efficient PDT / PTT for deep inflammation and tumor tissue, light should have less attenuation when penetrating biological tissue. Compared with NIR-I light source, NIR-II (1000-1700nm) is a better light source with inherent advantages such as small light scattering, deep tissue penetration depth, and high maximum allowable energy. In addition, during photoirradiation, NIR-II fluorescence imaging can be used to visualize deep inflammation and tumors, which can realize the integrated diagnosis and treatment of inflammation and tumors in the NIR-II region and PDT / PTT. Therefore, there is an urgent need to develop fluorescent molecular probes and photodynamic / photothermal reagents that absorb and fluoresce simultaneously in the range of 1000-1700 nm. Summary of the Invention

[0004] In order to improve the above technical problems, the present invention provides a near-infrared second-region xanthene derivative having a structure as shown in formula (1):

[0005]

[0006] Wherein, R1 and R2 are the same or different and are independently selected from -H, -C 1-8 Alkyl, -halogen, -halogenated C 1-8 Alkyl, -OH, -OC 1-8Alkyl, -NH2, -NH-C 1-8 Alkyl, -N-(C 1-8 Alkyl)2, -NO2, -CN, -C 1-8 Alkyl-COOH, -COOH, -CO-OC 1-8 Alkyl, -SO3H, -SO3-C 1-8 alkyl;

[0007] R3 and R4 are the same or different and are independently selected from -H, -C 1-8 Alkyl or -C 6-14 aryl;

[0008] Each X is the same or different and is independently selected from -O-, -S- or -Se-;

[0009] Y is selected from anions, for example monovalent anions such as ClO4 - 、Cl - Br - , I - PF6 - 、BF4 - 、CH3COO - CF3COO - 、CH3SO3 - or CF3SO3 - ;

[0010] Z is selected from -NH-, -O-, -S- or -Se-;

[0011] R is selected from the following formula (1-1) or formula (1-2):

[0012]

[0013] In formula (1-1), R5, R6, and R7 are the same or different and are independently selected from -H, -C 1-8 Alkyl, -halogen, -halogenated C 1-8 Alkyl, -OH, -OC 1-8 Alkyl, -NO2, -CN, -NH2, -NH-C 1-8 Alkyl, -N(C 1-8 Alkyl)2, -C 1-8 Alkyl-COOH, -COOH, -CO-OC 1-8 Alkyl, -SO3H, -SO3-C 1-8 alkyl;

[0014] In formula (1-2), 0≤m≤8, 0≤n≤100, 0≤p≤8; m, n, p are zero or positive integers; the connecting group M is selected from -O-, -NH-, -COO-, -OCO-, -CONH-, -NHCO-; the terminal group T is selected from -H, -C 1-8 Alkyl, -OH, -OC 1-8 Alkyl, -SH, -SO3H, -C 6-14 Aryl, -COOH, -COOC 1-8 alkyl;

[0015] According to an embodiment of the present invention, R1 and R2 are the same or different and are independently selected from -H, -CH3, -C2H5, -F, -Cl, -Br, -I, -CF3, -OH, -OCH3, -OC2H5, -N(CH3)2, -N(C2H5)2, -NO2, -CN, -COOH, -CH2COOH, -COOCH3, -SO3H.

[0016] According to an embodiment of the present invention, R3 and R4 are the same or different and are independently selected from -H, -CH3, -C2H5, and phenyl.

[0017] According to an embodiment of the present invention, Y is selected from ClO4 - Br - , I - PF6 - 、BF4 - CF3COO - 、CH3SO3 - or CF3SO3 - .

[0018] According to an embodiment of the present invention, in formula (1-1), R5, R6, and R7 are the same or different and are independently selected from -H, -CH3, -C2H5, -F, -Cl, -Br, -I, -CF3, -OH, -OCH3, -OC2H5, -NO2, -CN, -N(CH3)2, -N(C2H5)2, -COOH, -CH2COOH, -COOCH3, -COOC2H5, and -SO3H.

[0019] According to an embodiment of the present invention, in formula (1-2), m is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8; n is selected from an integer between 0 and 80; p is selected from 0, 1, 2, 3, 4, 5, 6, 7 or 8; the linking group M is selected from -O-, -NH-, -COO-, -OCO-, -CONH-, -NHCO-; the terminal group T is selected from -H, -OH, -OC 1-6 Alkyl, -SH, -SO3H, -COOH, -COOC 1-6 Alkyl, -C6-8 aryl;

[0020] According to an embodiment of the present invention, in formula (1-2), m is selected from 1, 2 or 3; n is selected from an integer between 10 and 60, for example, 20, 30, 40, 50; p is selected from 1, 2 or 3; the connecting group M is -O-, -NH-, -COO-, -OCO-, -CONH-, -NHCO-; and the terminal group T is selected from -H, -OH, -COOH, -SO3H, -OCH3.

[0021] According to an embodiment of the present invention, the compound represented by formula (1) has a structure represented by the following formula (2) or (3):

[0022]

[0023] wherein R1, R2, R3, R4, R5, R6, R7, X, Y, Z, M, T, m, p, and n independently have the definitions described above.

[0024] According to an embodiment of the present invention, the compound represented by formula (1) has the structure represented by CL1-CL31 below:

[0025] The present invention provides a method for synthesizing the near-infrared second-region xanthene derivative, comprising the following steps: reacting intermediate IV with R-ZH to obtain a compound represented by formula (1);

[0026]

[0027] wherein R, R1, R2, R3, R4, X, Y, and Z are independently defined above;

[0028] According to an embodiment of the present invention, the reaction is carried out in an organic solvent, for example, one or more selected from N,N-dimethylformamide, N,N-dimethylacetamide, N,N-dimethylaniline, dimethyl sulfoxide, acetonitrile; preferably N,N-dimethylformamide or dimethyl sulfoxide;

[0029] According to an embodiment of the present invention, the reaction is carried out in the presence of a catalyst, and the catalyst is, for example, selected from a base, specifically, one or more selected from triethylamine, pyridine, piperidine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, cesium carbonate, potassium hydroxide, and sodium hydroxide; preferably triethylamine or potassium carbonate;

[0030] According to an embodiment of the present invention, the molar ratio of the intermediate IV to R-ZH is 1:1 to 1:10;

[0031] According to an embodiment of the present invention, the catalyst is 0.1 to 10 times the equivalent of intermediate IV;

[0032] According to an embodiment of the present invention, the reaction temperature is 10-200° C., for example, 30-120° C.; the reaction time is 0.5-24 h, for example, 1-12 h.

[0033] According to an embodiment of the present invention, the preparation method of intermediate IV comprises: reacting intermediate I, intermediate II, and intermediate III to obtain intermediate IV;

[0034]

[0035] According to an embodiment of the present invention, the above reaction is carried out in an organic solvent, and the organic solvent is selected from one or more of formic acid, acetic acid, propionic acid, butyric acid, n-butanol, benzene, chlorobenzene, and toluene; preferably, the organic solvent is acetic acid or a n-butanol / toluene mixed solvent; the volume ratio of the n-butanol / toluene mixed solvent is 0.1 to 10;

[0036] According to an embodiment of the present invention, the molar ratio of the intermediate I, intermediate II and intermediate III is 1: (0.5-5): (0.5-5), for example 1: (0.8-3): (0.8-3), exemplified by 1: 1: 1;

[0037] According to an embodiment of the present invention, the reaction temperature is 10-200°C, for example 30-120°C; the reaction time is 0.5-24h, for example 1-12h;

[0038] The present invention also provides the use of the near-infrared second-region xanthene derivative as a photosensitizer.

[0039] The present invention also provides uses of the NIR II xanthene derivatives for biological imaging, such as imaging of blood vessels, organs, or tumors. Examples of such imaging include fluorescence imaging of cells and biological tissues in the NIR II, vascular imaging in the NIR II, tumor vascular imaging in the NIR II, and organ imaging in the NIR II. In particular, these derivatives are used for vascular imaging of deep-seated tumors.

[0040] The present invention also provides a use of the near-infrared second-zone xanthene derivative for treating tumors or inflammation, in particular for photodynamic and photothermal therapy of tumors and inflammation.

[0041] The present invention also provides the use of the near-infrared second-zone xanthene derivative in the preparation of biological imaging reagents, especially in the preparation of vascular imaging reagents, tumor vascular imaging reagents, or tumor fluorescence guidance imaging reagents.

[0042] The present invention also provides the use of the near-infrared second-zone xanthene derivative in the preparation of anti-tumor, anti-bacterial, anti-fungal or anti-inflammatory diagnostic and therapeutic reagents.

[0043] According to an embodiment of the present invention, the application in the preparation of biological imaging reagents and fluorescent diagnostic reagents is fluorescence imaging of cells and biological tissues in the near-infrared region 2, near-infrared region 2 blood vessel imaging, near-infrared region 2 tumor blood vessel imaging, and near-infrared region 2 organ imaging.

[0044] According to an embodiment of the present invention, the application in preparing fluorescent diagnostic reagents and photosensitizers is a photodynamic anti-tumor application.

[0045] According to an embodiment of the present invention, the application in the preparation of fluorescent guidance reagents and photothermal reagents is a photothermal anti-tumor application.

[0046] According to an embodiment of the present invention, the application in the preparation of fluorescent guidance reagents and photodynamic / photothermal reagents is a photodynamic / photothermal antibacterial application, and the bacteria are bacteria or fungi.

[0047] According to an embodiment of the present invention, the bacteria are, for example, Gram-positive bacteria, Staphylococcus aureus, Gram-negative bacteria, or Escherichia coli.

[0048] According to an embodiment of the present invention, the fungus is, for example, Aspergillus or Candida albicans.

[0049] The present invention also provides a bioimaging and / or photodynamic / photothermal agent, which comprises the near-infrared second-zone xanthene derivative of the present invention.

[0050] The present invention also provides a fluorescent diagnostic reagent and / or a photodynamic / photothermal reagent, which includes the near-infrared second-zone xanthene derivative of the present invention.

[0051] According to an embodiment of the present invention, the reagent further comprises fetal bovine serum (FBS).

[0052] According to an embodiment of the present invention, the reagent further comprises a high molecular weight polymer F127 (Pluronic F127). Preferably, in the reagent, the high molecular weight polymer F127 encapsulates the xanthene derivative to form a liposome.

[0053] Optionally, the preparation of the reagent comprises the following steps:

[0054] Prepare a mixed solution of near-infrared region II xanthene derivatives and dimethyl sulfoxide to a concentration of 10 -6The dye is added to the same volume of fetal bovine serum (FBS) solution, and 8 times the volume of HEPES buffer solution (pH = 7.4) is added, and incubated at 37 ° C for 30-180 min, then dialyzed using a dialysis bag (molecular weight cutoff 3500 KDa), and then concentrated using an ultrafiltration tube (molecular weight cutoff 10 KDa, 30 KDa or 100 KDa) to make 100 μL FBS solution contain 1-1000 μg of dye, thereby obtaining the reagent with a final concentration of 0.001-10 mM.

[0055] According to an exemplary embodiment of the present invention, the preparation of the reagent comprises the following steps:

[0056] A near-infrared second-zone xanthene derivative and a block polymer F127 are dissolved in chloroform and quickly injected into deionized water. An emulsion is obtained by ultrasonication, and the chloroform is removed by rotary evaporation. The mixture is then dialyzed using a dialysis bag (molecular weight cut-off 3500KDa) and concentrated using an ultrafiltration tube (molecular weight cut-off 10KDa, 30KDa or 100KDa) to obtain the reagent with a final concentration of 0.001 to 10 mg / mL. The mass ratio of the near-infrared second-zone xanthene derivative to the block polymer F127 is 1:1 to 1:100.

[0057] According to an exemplary embodiment of the present invention, the preparation of the reagent comprises the following steps:

[0058] A near-infrared second-zone xanthene derivative and a block polymer F127 are dissolved in chloroform, sonicated, and the chloroform is removed by rotary evaporation. The mixture is vacuum dried, deionized water is added, sonicated, and then dialyzed using a dialysis bag (molecular weight cutoff 3500KDa). The mixture is then concentrated using an ultrafiltration tube (molecular weight cutoff 10KDa, 30KDa or 100KDa) to obtain the reagent, with a final concentration of 0.001 to 10 mg / mL. The mass ratio of the near-infrared second-zone xanthene derivative to the block polymer F127 is 1:1 to 1:100.

[0059] Beneficial effects

[0060] The present invention provides a near-infrared region II xanthene derivative. Two xanthene groups are fused with a typical cyanine dye bridge, and the unstable active site chlorine atom is replaced with a nucleophilic reagent. This results in a significant red-shift in the maximum absorption / emission wavelength of the near-infrared region II xanthene derivative, with the maximum wavelength reaching above 1200 nm and the tail peak being extended to above 1500 nm. The derivative exhibits good photostability, pH stability, and excellent biocompatibility, as well as a higher molar extinction coefficient, fluorescence quantum yield, singlet oxygen quantum yield, and photothermal conversion efficiency. Furthermore, the derivative exhibits low cytotoxicity. Under photosensitivity conditions, it can effectively generate a large amount of reactive oxygen species and heat, and can be used for near-infrared region II vascular imaging of deep-seated tumors, as well as photodynamic and photothermal therapy of deep-seated tumors and inflammation. Therefore, the derivative has great potential as a near-infrared fluorescent reagent in the preparation of vascular imaging reagents, tumor vascular imaging reagents, tumor fluorescence diagnostic imaging reagents, and in the preparation of anti-tumor, antibacterial, antifungal, and anti-inflammatory phototherapeutic biomaterials. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0062] Figure 1 The absorption spectra of the second-near-infrared xanthene derivative CL1 in Example 1 and the second-near-infrared xanthene derivatives CL2 and CL3 in Example 2 of the present invention are shown.

[0063] Figure 2 The fluorescence spectra of the second-near-infrared xanthene derivative CL1 in Example 1 and the second-near-infrared xanthene derivatives CL2 and CL3 in Example 2 of the present invention are shown.

[0064] Figure 3 A comparison chart of the photostability of ICG, the near-infrared region II xanthene derivative CL1 in Example 1 of the present invention, and the near-infrared region II xanthene derivatives CL2 to CL4 in Example 2 is shown.

[0065] Figure 4 Schematic diagrams showing the interaction between the near-infrared second region xanthene derivatives CL1 and ICG and the singlet oxygen scavenger in Example 1 of the present invention.

[0066] Figure 5 The figures show the heat generation of ICG, the near-infrared second region xanthene derivative CL1 in Example 1 of the present invention, and the near-infrared second region xanthene derivatives CL2 and CL3 in Example 2 under near-infrared second region laser irradiation.

[0067] Figure 6 The figure shows the near-infrared second-zone fluorescence imaging of the CL1 / FBS complex prepared based on the near-infrared second-zone xanthene derivative CL1 prepared in Example 1 of the present invention in Hela cells.

[0068] Figure 7 The figure shows the near-infrared second-zone fluorescence imaging of tumor blood vessels in tumor-bearing mice of the CL1 / FBS complex prepared based on the near-infrared second-zone xanthene derivative CL1 prepared in Example 1 of the present invention.

[0069] Figure 8 The figure shows the near-infrared second-zone fluorescence imaging of tumors in tumor-bearing mice of the CL1 / FBS complex prepared based on the near-infrared second-zone xanthene derivative CL1 prepared in Example 1 of the present invention.

[0070] Figure 9 The figure shows the near-infrared second-zone fluorescence imaging of liposome CL2 NPs prepared based on the near-infrared second-zone xanthene derivative CL2 prepared in Example 2 of the present invention in the hind limb blood vessels of mice.

[0071] Figure 10 The dark toxicity graph (a) and phototoxicity graph (b) of different concentrations of ICG and the CL1 / FBS complex prepared based on the near-infrared second-zone xanthene derivative CL1 prepared in Example 1 of the present invention on Hela cells are shown.

[0072] Figure 11 The dark toxicity and phototoxicity of liposome CL2 NPs prepared based on the near-infrared second-zone xanthene derivative CL2 prepared in Example 2 of the present invention at different concentrations to Hela cells are shown.

[0073] Figure 12 The dark toxicity and phototoxicity of liposome CL3 NPs prepared based on the near-infrared second-zone xanthene derivative CL3 prepared in Example 2 of the present invention at different concentrations to Gram-positive bacteria are shown.

[0074] Figure 13 The dark toxicity and phototoxicity of liposomes CL3 NPs prepared based on the near-infrared second-zone xanthene derivative CL3 prepared in Example 2 of the present invention at different concentrations to Aspergillus are shown.

[0075] Definitions and Explanations of Terms

[0076] Unless otherwise indicated, the definitions of groups and terms in this specification and claims, including definitions used as examples, exemplary definitions, preferred definitions, definitions in tables, and definitions of specific compounds in the Examples, may be arbitrarily combined and coupled with one another. The group definitions and compound structures resulting from such combinations and couplings should be understood to be within the scope of this specification and / or claims.

[0077] Unless otherwise indicated, the numerical ranges recited in this specification and claims are equivalent to reciting at least each specific integer value therein. For example, the numerical range "1-40" is equivalent to reciting each integer value in the numerical range "1-10", namely, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and each integer value in the numerical range "11-40", namely, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40.

[0078] The term "halogen" refers to fluorine, chlorine, bromine and iodine.

[0079] The term "C 1-8 "Alkyl" means straight-chain and branched alkyl groups having 1, 2, 3, 4, 5, 6, 7 or 8 carbon atoms, "C 1-6 The term "alkyl" refers to straight-chain and branched alkyl groups having 1, 2, 3, 4, 5 or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, or the like or isomers thereof.

[0080] The term "C 6-14 "Aryl" is understood to mean preferably a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring ("C 6-14 or a ring having 9 carbon atoms ("C9 aryl"), for example indanyl or indenyl, or a ring having 10 carbon atoms ("C 10aryl) such as tetrahydronaphthyl, dihydronaphthyl or naphthyl, or a ring having 13 carbon atoms ("C 13 aryl), such as fluorenyl, or a ring having 14 carbon atoms ("C 14 aryl”), such as anthracenyl. When the C 6-14 When the aryl group is substituted, it may be monosubstituted or polysubstituted. Furthermore, there is no limitation on the position of substitution, and for example, substitution may be at the ortho, para or meta position. DETAILED DESCRIPTION

[0081] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0082] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0083] Example 1

[0084]

[0085] Intermediate compound 1 (0.71 g, 2.0 mmol) and intermediate compound 2 (0.17 g, 1 mmol) were dissolved in 100 mL of acetic acid, heated to 50°C, and stirred for 2 h. The solvent was then removed by vacuum concentration. The crude product was separated by silica gel column chromatography (mobile phase: ethyl acetate:ethanol = 10:1) to obtain pure intermediate compound 3 in a 67% yield. H Spectrum: (400 MHz, CDCl3): δ 8.24 (s, 2H), 7.56 (s, 2H), 6.38 (s, 4H), 5.42 (s, 4H), 4.62 (s, 6H), 3.58 (s, 10H), 2.79 (s, 8H), 1.68 (s, 12H). MS (ESI): 647.3.

[0086] Intermediate compound 3 (0.89 g, 1.0 mmol), intermediate compound 4 (0.18 g, 1.0 mmol) and triethylamine (TEA, 0.01 g, 0.1 mmol) were dissolved in 100 mL of N,N-dimethylformamide (DMF) and reacted at room temperature for 0.5 h. The solvent was removed by vacuum concentration, and the crude product was separated by silica gel column chromatography (mobile phase: ethyl acetate:ethanol = 5:1) to obtain pure CL1 with a yield of 48%. Hydrogen spectrum: (400 MHz, CDCl3): δ9.58 (s, 2H), 8.76 (s, 2H), 8.27 (s, 2H), 7.74 (s, 2H), 7.54 (s, 4H), 6.83 (s, 4H), 5.53 (s, 6H), 4.68 (s, 10H), 3.83 (s, 8H), 2.26 (s, 12H), mass spectrum MS (ESI): 789.4.

[0087] Example 2

[0088]

[0089] The intermediate compound 3 reacted with the raw material 5 to obtain products CL2 to CL7. The synthesis method was similar to that of CL1 in Example 1. The characterization results are shown in Table 1.

[0090] Example 3

[0091]

[0092] Intermediate compounds 6 and 7 reacted with intermediate compound 2 to obtain intermediate 8. Intermediate compound 8 reacted with raw material 9 to obtain products CL8 to CL13. Their synthesis methods were similar to those of CL1 in Example 1. The characterization results are shown in Table 1.

[0093] Example 4

[0094]

[0095] Intermediate compounds 10 and 11 react with intermediate compound 2 to obtain intermediate 12. Intermediate compound 12 reacts with raw material 13 to obtain products CL14 to CL19. Their synthesis methods are similar to those of CL1 in Example 1. The characterization results are shown in Table 1.

[0096] Example 5

[0097]

[0098] Intermediate compound 14 reacts with intermediate compound 2 to obtain intermediate 15, and intermediate compound 15 reacts with raw material 16 to obtain products CL20 to CL25. The synthesis method is similar to that of CL1 in Example 1. The characterization results are shown in Table 1.

[0099] Example 6

[0100]

[0101] The intermediate compound 3 reacted with the raw material 17 to obtain products CL26 to CL31. The synthesis method was similar to that of CL1 in Example 1. The characterization results are shown in Table 1.

[0102] Table 1: Characterization data of some xanthene derivatives of the present invention

[0103]

[0104] Example 7

[0105] Preparation method of near-infrared region II xanthene derivative complex with fetal bovine serum (FBS). Taking dye CL1 as an example, the specific steps are as follows:

[0106] Prepare 1 mL of a mixed solution of CL1 and dimethyl sulfoxide to a concentration of 10 -4 mol / L, added to 1 mL of fetal bovine serum (FBS) solution, and 8 mL of HEPES buffer solution (pH = 7.4), incubated at 37 ° C for 120 min, then dialyzed using a dialysis bag (molecular weight cutoff 3500 KDa), and then concentrated using an ultrafiltration tube (molecular weight cutoff 10 KDa, 30 KDa or 100 KDa) to make 100 μL FBS solution contain 80 μg of dye CL1, to obtain the fluorescent guidance reagent and photodynamic / photothermal reagent CL1 / FBS, with a final concentration of 1 mM.

[0107] Example 8

[0108] A method for preparing liposomes using near-infrared region II xanthene derivatives and block polymer F127 (Pluronic F127). Using dye CL2 as an example, the specific steps are as follows:

[0109] CL2 (1 mg) and F127 (10 mg) were dissolved in 1 mL of chloroform and quickly injected into 10 mL of deionized water. The emulsion was obtained by ultrasonication, and the chloroform was removed by rotary evaporation. The solution was then dialyzed using a dialysis bag (molecular weight cutoff 3500 KDa) and concentrated using an ultrafiltration tube (molecular weight cutoff 10 KDa, 30 KDa, or 100 KDa) to obtain the fluorescent guidance reagent and photodynamic / photothermal reagent CL2 NPs with a final concentration of 1 mg / mL.

[0110] Example 9

[0111] A method for preparing liposomes using near-infrared region II xanthene derivatives and block polymer F127. Using dye CL3 as an example, the specific steps are as follows:

[0112] CL3 (1 mg) and F127 (10 mg) were dissolved in 1 mL of chloroform, sonicated, and the chloroform was removed by rotary evaporation. The mixture was vacuum dried, deionized water was added, sonicated, and then dialyzed using a dialysis bag (molecular weight cutoff 3500 KDa). The mixture was then concentrated using an ultrafiltration tube (molecular weight cutoff 10 KDa, 30 KDa, or 100 KDa) to obtain the fluorescent guidance reagent and photodynamic / photothermal reagent CL3 NPs with a final concentration of 1 mg / mL.

[0113] Example 10

[0114] Dark cytotoxicity assay:

[0115] The cultured HeLa cells were digested with 0.25% trypsin and pipetted to prepare a single cell suspension. The cell number was adjusted to about 2 × 10 4 Cells were plated at a concentration of 500 μL / well in a 96-well culture plate at 37°C in a 5% CO2 incubator. After cell attachment, the supernatant was discarded. Different concentrations of biomaterials (ICG, CL1 / FBS, CL2 NPs, and CL3 NPs) were added according to the experimental design under strict light-shielding conditions. The plates were then incubated for 1 hour at 37°C in a 5% CO2 incubator. Cell viability was assessed using the MTT assay. 20 μL of MTT (5 mg / mL in PBS) was added to each well. The plates were incubated for 4 hours at 37°C in a 5% CO2 incubator. The supernatant was carefully aspirated and discarded. 150 μL of dimethyl sulfoxide (DMSO) was then added to each well. The plates were shaken on a microshaker for 10 minutes to fully dissolve the purple crystals. The wavelength was 570 nm, and the optical density (OD value) of each well was measured on a microplate reader. The cell survival rate was calculated according to the following formula: cell survival rate = OD value of experimental group / OD value of blank group × 100%.

[0116] Example 11

[0117] Cell phototoxicity experiment:

[0118] The cultured HeLa cells were digested with 0.25% trypsin and perforated to prepare a single cell suspension. The cell number was adjusted to about 2 × 10 4 Cells were plated at 400 μL / mL, and 200 μL per well was inoculated in a 96-well culture plate and cultured in an incubator at 37°C containing 5% CO2. After the cells adhered, the supernatant was discarded and different concentrations of biomaterials (ICG, CL1 / FBS, CL2 NPs, CL3 NPs) were added according to the experimental design under strict light-proof conditions. The cells were then placed in an incubator at 37°C containing 5% CO2 and cultured for 1 hour. A 1064 nm semiconductor laser was then used for irradiation, and the power density was adjusted to 1.0 W / cm 2The light beam was evenly and vertically irradiated onto a 96-well culture plate for 1000 seconds. A blank control group was set up in each 96-well culture plate, with 6 wells for each condition. After illumination, cells were incubated in a 37°C incubator with 5% CO2 for 24 hours, and then cell viability was assessed. Cell viability was assessed using the MTT assay. 20 μL of MTT (5 mg / mL in PBS) was added to each well. The cells were incubated in a 37°C incubator with 5% CO2 for 4 hours, then the cells were terminated. The supernatant was carefully aspirated and 150 μL of dimethyl sulfoxide (DMSO) was added to each well. The cells were shaken on a microplate oscillator for 10 minutes to fully dissolve the purple crystals. The optical density (OD) of each well was measured on a microplate reader at a wavelength of 570 nm. Cell viability was calculated according to the following formula: Cell viability = OD value of experimental group / OD value of blank group × 100%.

[0119] Example 12

[0120] Bacterial dark toxicity experiment:

[0121] Take 5 mL of CL3 NPs solution and place it in a sterile tube. Add 0.1 mL of Gram-positive bacteria suspension to make the final bacterial concentration 10 8 CFU / mL. Place the centrifuge tube in a 37°C constant temperature shaker and incubate in the dark for 24 hours. Then spread the mixture on an agar plate and incubate the plate at 37°C for another 24 hours. Count the number of bacteria on the plate. Repeat six times for each sample and calculate the average. The bacterial survival rate without sample addition is considered 100%. Calculate the inhibition rate according to the following formula: Bacterial inhibition rate = number of bacteria in the experimental group / number of bacteria in the blank group × 100%.

[0122] Example 13

[0123] Bacterial phototoxicity experiment:

[0124] Take 5 mL of CL3 NPs solution and place it in a sterile tube. Add 0.1 mL of Gram-positive bacteria suspension to make the final bacterial concentration 10 8 CFU / mL, place the centrifuge tube in a 37°C constant temperature shaker and incubate in the dark for 24 h, then irradiate the mixture with near-infrared light and adjust the power density to 1.0 W / cm 2 The light beam was evenly and vertically irradiated onto the centrifuge tube for 1000 seconds. The mixture was then spread onto an agar plate and incubated at 37°C for 24 hours. The number of bacteria in the plate was counted. This was repeated six times for each sample and the average was calculated. The bacterial survival rate without sample was considered 100%. The inhibition rate was calculated using the following formula: Bacterial inhibition rate = Number of bacteria in the experimental group / Number of bacteria in the blank group × 100%.

[0125] Example 14

[0126] Fungal dark toxicity test:

[0127] Take 5 mL of CL3 NPs solution and place it in a sterile tube. Add 0.1 mL of Aspergillus suspension to make the final fungal concentration 10 8 CFU / mL. Place the centrifuge tube in a 37°C constant temperature shaker and incubate in the dark for 24 hours. Then spread the mixture onto an agar plate and incubate the plate at 37°C for another 24 hours. Count the number of bacteria on the plate. Repeat six times for each sample and calculate the average. The fungal survival rate without sample addition is considered 100%. Calculate the fungal inhibition rate using the following formula: Fungal inhibition rate = Number of bacteria in the experimental group / Number of bacteria in the blank group × 100%.

[0128] Example 15

[0129] Fungal phototoxicity experiment:

[0130] Take 5 mL of CL3 NPs solution and place it in a sterile tube. Add 0.1 mL of Aspergillus suspension to make the final fungal concentration 10 8 CFU / mL, place the centrifuge tube in a 37°C constant temperature shaker and incubate in the dark for 24 h, then irradiate the mixture with near-infrared light and adjust the power density to 1.0 W / cm 2 The light beam was evenly and vertically irradiated onto the centrifuge tube for 1000 seconds. The mixture was then spread onto an agar plate and incubated at 37°C for 24 hours. The number of bacteria in the plate was counted. This was repeated six times for each sample, and the average was calculated. The fungal survival rate without the sample was considered 100%. The inhibition rate was calculated using the following formula: Fungal inhibition rate = Number of bacteria in the experimental group / Number of bacteria in the blank group × 100%.

[0131] Example 16

[0132] Tumor vascular imaging:

[0133] After the tumor-bearing mice were anesthetized, 100 μL (1 mM) of the CL1 / FBS complex prepared in Example 7 of the present invention was injected into the tail vein of the tumor-bearing mice. The tumor vessels were imaged using a near-infrared two-zone imaging system. The external laser was 1064 nm and the laser power was 100 mW / cm 2 , the resolution of tumor blood vessels is below 0.1mm.

[0134] Example 17

[0135] Vascular imaging:

[0136] After the mice were anesthetized, 100 μL (1 mg / mL) of the CL2 NPs solution prepared in Example 8 of the present invention was injected into the tail vein of the mice. The hind limb blood vessels were imaged using a near-infrared two-zone imaging system. The external laser was 1064 nm and the laser power was 100 mW / cm 2 , the blood vessel resolution is below 0.1mm.

[0137] Example 18

[0138] Tumor phototherapy:

[0139] After the mice were anesthetized, 100 μL (1 mM) of the CL1 / FBS complex prepared in Example 7 of the present invention was injected into the tail vein of the tumor-bearing mice. 24 hours later, the tumor site was irradiated with a near-infrared zone II laser for 5 minutes at a laser power of 1.0 W / cm 2 The tumor volume was measured at the same time intervals, and the tumor inhibition rate was calculated, which was greater than 80%.

[0140] Example 19

[0141] Phototherapy of bacterial infections:

[0142] After the mice were anesthetized, 100 μL (1 mg / mL) of the CL3 NPs solution prepared in Example 9 of the present invention was injected subcutaneously into the bacterial infection site. The bacterial infection site was irradiated with a near-infrared zone II laser for 5 min at a laser power of 1.0 W / cm 2 The area of ​​bacterial infection was measured at the same interval and the wound healing rate was calculated, which was greater than 80%.

[0143] Example 20

[0144] Phototherapy of fungal infections:

[0145] After the mice were anesthetized, 100 μL (1 mg / mL) of the CL3 NPs solution prepared in Example 9 of the present invention was subcutaneously injected into the fungal infection site. The fungal infection site was irradiated with a near-infrared zone II laser for 5 min at a laser power of 1.0 W / cm 2 , the area of ​​fungal infection was measured at the same interval, and the healing rate of the wound was calculated, which was greater than 80%.

[0146] Conclusion: The near-infrared zone II xanthene derivatives prepared by the present invention are formed by fusing two xanthene groups with a typical cyanine dye bridge and replacing the unstable active site chlorine atom with a nucleophile, so that the maximum absorption / emission wavelength of the near-infrared zone II xanthene derivatives is significantly red-shifted, with the maximum wavelength reaching above 1200 nm and the tail peak being delayed to above 1500 nm. Such derivatives can efficiently generate singlet oxygen and heat, have good biocompatibility, and excellent phototherapy ability for tumor cells, bacteria and fungi.

[0147] Indocyanine green (ICG) has good fluorescence imaging and photodynamic / photothermal effects and has been approved by the U.S. FDA as a fluorescence imaging agent and photodynamic / photothermal agent for clinical research. However, its disadvantages are short maximum absorption / emission wavelengths and poor photostability. The near-infrared region II xanthene derivatives of the present invention have longer maximum absorption / emission wavelengths and have very wide and strong absorption in the near-infrared region II window (1000-1700nm). Its maximum absorption / emission wavelength is around 1200nm (as shown in Table 1), and its molar extinction coefficient is 20,000 to 100,000nm. -1 cm -1 It exhibits extremely strong near-infrared second-region light absorption ability, a fluorescence quantum yield of about 0.01 to 1%, and excellent light stability and pH stability.

[0148] Figure 1 This is the absorption spectrum of the near-infrared region II xanthene derivatives prepared by the present invention. It can be seen from the figure that the maximum absorption wavelength of CL1 to CL3 is around 1160nm, and they have a relatively broad near-infrared region II absorption in the wavelength range of 1000-1300nm, so they can be used for photodynamic / photothermal therapy with laser irradiation within this wavelength range.

[0149] Figure 2 The fluorescence spectrum of the near-infrared region II xanthene derivative prepared by the present invention shows that the maximum emission wavelength of CL1 to CL3 is around 1200 nm, and it has a relatively broad near-infrared region II emission within the wavelength range of 1100-1500 nm. Compared with the near-infrared region I emission below 1000 nm, the absorption of light and autofluorescence of biological tissues in this wavelength range rapidly decay, which can greatly improve the imaging contrast. Therefore, it can be used for fluorescence imaging within this wavelength range.

[0150] As shown in Table 1, the other near-infrared region II xanthene derivatives of the present invention have a maximum absorption wavelength of approximately 1160 nm and a maximum emission wavelength of above 1200 nm. They all have relatively broad near-infrared region II emission properties and can be applied to fluorescence imaging within this wavelength range. They can also be applied to photodynamic / photothermal therapy using laser irradiation within this wavelength range, and have significant antibacterial and antifungal properties and tumor treatment properties.

[0151] Figure 3 The photostability comparison of the near-infrared region II xanthene derivatives prepared by the present invention and ICG is shown in the figure. As can be seen from the figure, after 60 minutes of red light irradiation, the absorbance at the maximum absorption wavelengths of CL1 in Example 1 and CL2 in Example 2 decreased by less than 20%, and the absorbance at the maximum absorption wavelengths of CL3 and CL4 in Example 2 decreased by less than 10%. Under the same conditions, the absorbance at the maximum absorption wavelength of ICG decreased by nearly 90%. Therefore, under the same conditions, the near-infrared region II xanthene derivatives prepared by the present invention have better photostability than ICG. Furthermore, the introduction of a cyclohexene structure into the ethylene chain of the molecule and the introduction of xanthene structures at both ends of the molecule increase the steric hindrance of the molecule, significantly enhancing the photostability of the near-infrared region II xanthene derivatives. All other xanthene derivatives in the present invention have better photostability than ICG and exhibit significant anti-bleaching properties, demonstrating the potential application of the near-infrared region II xanthene derivatives in the present invention as alternatives to the commercial photosensitizer ICG.

[0152] The efficiency of a photosensitizer in generating reactive oxygen species is a key parameter for determining its efficacy in photodynamic therapy. Photosensitizers with high singlet oxygen efficiencies have great clinical application prospects. The ability of near-infrared II xanthene derivatives to generate reactive oxygen species is shown in Table 1. Experimental results show that, as measured using singlet oxygen scavengers, the near-infrared II xanthene derivatives of the present invention can efficiently generate singlet oxygen under near-infrared II laser irradiation. The singlet oxygen quantum yield of ICG is less than 0.1, while the singlet oxygen quantum yields of CL1 to CL31 in Examples 1 to 6 are as high as 0.1 to 0.2, comparable to other common photosensitizers such as hypocrellin derivatives and porphyrin derivatives. They can effectively kill tumor cells, bacteria, and fungi under illumination.

[0153] Figure 4 This is a comparison chart of the reactive oxygen species generation efficiency of the near-infrared region II xanthene derivatives CL1 and ICG prepared by the present invention. As can be seen from the figure, the singlet oxygen scavenger TEMP alone does not produce any reactive oxygen species generation signal under light irradiation, and ICG produces a weak singlet oxygen signal under near-infrared light irradiation. However, the near-infrared region II xanthene derivative CL1 prepared by the present invention produces a strong singlet oxygen signal under near-infrared light irradiation. This shows that the ability of CL1 to generate reactive oxygen species is far higher than that of commercial photosensitizers used in clinical applications, and it has the potential to replace ICG in clinical applications.

[0154] The photothermal conversion efficiency of a photothermal agent is a key parameter for determining the efficacy of its photothermal therapy. Photosensitizers with high photothermal conversion efficiency have great clinical application prospects. The heat generation capacity of near-infrared region II xanthene derivatives is shown in Table 1. Experiments have shown that near-infrared region II xanthene derivatives can efficiently generate heat under near-infrared region II laser irradiation. The photothermal conversion efficiency of ICG is less than 20%. The photothermal conversion efficiency of CL1 to CL31 in Examples 1 to 6 is all above 40%. This value is comparable to other common types of photosensitizers such as hypocrellin derivatives and cyanine dyes, and can effectively kill tumor cells, bacteria, and fungi under light.

[0155] Figure 5 This is a comparison of the photothermal efficiency of the near-infrared region II xanthene derivatives CL1-CL3 and ICG prepared by the present invention. As can be seen from the figure, ICG has a poor photothermal effect under near-infrared light irradiation. This elevated temperature makes it difficult to kill common tumor cells, bacteria, and fungi. Therefore, ICG has not yet been clinically used as a photothermal agent. However, the near-infrared region II xanthene derivatives CL1-CL3 prepared by the present invention have a significant photothermal effect under near-infrared light irradiation, with the photothermal temperature rising to more than 50 degrees Celsius. At this temperature, they can effectively kill common tumor cells, bacteria, and fungi. Other xanthene derivatives in the present invention also have excellent photothermal conversion efficiency (Table 1). Therefore, the near-infrared region II xanthene derivatives prepared by the present invention can be used as an alternative to the commercial photosensitizer ICG and have clinical application prospects.

[0156] Figure 6 The results of the cellular NIR-II fluorescence imaging experiments shown here demonstrate that the CL1 / FBS complex has good biocompatibility, can enter HeLa cells, and produces strong NIR-II fluorescence in the cells. Therefore, it can be used as a commercial NIR-II fluorescent dye for cell staining analysis. Other xanthene derivatives described in this invention also exhibit good cell staining properties and can be used as commercial fluorescent probes for analyzing life processes, energy conversion, metabolism, and the occurrence and evolution of diseases (Table 1).

[0157] Figure 7 The results of near-infrared zone II fluorescence imaging of tumor vessels in tumor-bearing mice demonstrate that when the CL1 / FBS complex (dose: 1 mM / kg), prepared based on the near-infrared zone II xanthene derivative CL1 prepared in Example 1, was injected into the tail vein of the tumor-bearing mice, the near-infrared zone II fluorescence of CL1 / FBS clearly identified tumor vessels. The near-infrared zone II xanthene derivatives of the present invention exhibit bright near-infrared zone II fluorescence and excellent tumor cell uptake, making them suitable commercial near-infrared zone II tumor vessel fluorescence imaging reagents for diagnosing early-stage tumor development and metastasis.

[0158] Figure 8The results of near-infrared zone II fluorescence imaging of tumors in tumor-bearing mice show that when a CL1 / FBS complex (dose: 1 mM / kg) prepared based on the near-infrared zone II xanthene derivative CL1 prepared in Example 1 was injected into the tail vein of the tumor-bearing mice, the near-infrared zone II fluorescence of CL1 / FBS clearly tracked the location of the tumor. The near-infrared zone II xanthene derivatives of the present invention can be used as diagnostic guides for commercial near-infrared zone II tumor fluorescence imaging, enabling tumor visualization for image-guided surgical resection, as well as integrated photodynamic / photothermal therapy for tumors and diagnosis and treatment.

[0159] Figure 9 The results of near-infrared zone II fluorescence imaging of mouse hindlimb blood vessels show that when liposomes (CL2 NPs) prepared based on the near-infrared zone II xanthene derivative CL2 prepared in Example 2 (dose: 1 mg / kg) were injected into the tail vein of mice, the near-infrared zone II fluorescence of the liposomes (CL2 NPs) clearly identified hindlimb blood vessels. The near-infrared zone II xanthene derivatives of the present invention can be used as commercial near-infrared zone II vascular fluorescence imaging reagents for the non-invasive diagnosis of cardiovascular and cerebrovascular diseases.

[0160] Cytotoxicity (dark toxicity) studies have shown that the cytotoxicity of the CL1 / FBS complex is low, similar to ICG. When Hela cells were incubated with 10 μM photosensitizer CL1 / FBS for 24 hours, no obvious death of Hela cells was observed. Figure 10 a), indicating that such biomaterials have essentially no cytotoxicity. Figure 10 Cell phototoxicity studies (b) demonstrate that CL1 / FBS exhibits highly potent killing activity against HeLa cells under near-infrared laser irradiation. A concentration of 10 μM kills over 90% of HeLa cells, while ICG kills only about 20% under the same conditions. This demonstrates that these near-infrared xanthene derivatives exhibit significantly superior phototherapy efficacy to ICG. Figure 11 Similar results were obtained in the dark toxicity and phototoxicity experiments on Hela cells of CL2 NPs.

[0161] The near-infrared zone II xanthene derivatives of the present invention can be used as commercial photosensitizers for optical therapy of tumors, with an IC50 value of less than 2 μM and extremely strong tumor cell destruction ability.

[0162] The bacterial toxicity (dark toxicity) study showed that the bacterial toxicity of the liposome CL3 NPs prepared based on the near-infrared second-zone xanthene derivative CL3 prepared in Example 2 was low ( Figure 12), after the bacteria were co-incubated with CL3 NPs for 24 hours, no obvious bacterial death was observed, indicating that this type of biomaterial has basically no bacterial toxicity. The results of bacterial phototoxicity research showed that after the bacteria were co-incubated with CL3 NPs and then irradiated with near-infrared zone II laser, they showed excellent killing power against bacteria.

[0163] Fungal toxicity (dark toxicity) studies have shown that CL3 NPs have low fungal toxicity ( Figure 13 ), after the fungi were co-incubated with CL3 NPs for 24 hours, no obvious death of the fungi was observed, indicating that this type of biomaterial has basically no fungal toxicity. The results of the fungal phototoxicity study showed that after the fungi were co-incubated with CL3 NPs and then irradiated with near-infrared zone II laser, they showed excellent lethality to the fungi.

[0164] The near-infrared second-zone xanthene derivatives of the present invention can be used as commercial photosensitizers for optical treatment of bacterial and fungal infections, with an inhibition rate of more than 80% and extremely strong ability to destroy inflammatory infections.

[0165] Compared with ICG, the near-infrared zone II xanthene derivatives of the present invention fuse two xanthene groups with a typical cyanine dye bridge and replace the unstable active site chlorine atom with a nucleophilic reagent, significantly red-shifting the absorption / emission wavelength to above 1200 nm, enhancing the molar extinction coefficient, having better photostability, and enhancing its ability to generate singlet oxygen and heat; such near-infrared zone II xanthene derivatives are prepared into FBS complexes or liposomes to improve the therapeutic effect; have good biocompatibility in cells or tissues; can be used as fluorescent imaging agents for tumor blood vessels and blood vessels, and as guide agents for fluorescent imaging of tumors; have good optical therapeutic effects on tumor cells, bacteria and fungi; it can be seen that the near-infrared zone II xanthene derivatives of the present invention have great application potential in the preparation of biomaterials for treating tumors, bacterial infections, fungal infections and inflammation.

[0166] The above is an exemplary description of the implementation methods of the technical solutions of the present invention. It should be understood that the scope of protection of the present invention is not limited to the above implementation methods. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A compound having a structure as shown in formula (1): in, R1 and R2 are the same or different and are independently selected from -H, -C 1-8 Alkyl, -halogen, -halogenated C 1-8 Alkyl, -OH, -OC 1-8 Alkyl, -NH2, -NH-C 1-8 Alkyl, -N-(C 1-8 Alkyl)2, -NO2, -CN, -COOH, -C 1-8 Alkyl-COOH, -CO-OC 1-8 Alkyl, -SO3H, -SO3-C 1-8 alkyl; R3 and R4 are the same or different and are independently selected from -H, -C 1-8 Alkyl or -C 6-14 aryl; Each X is the same or different and is independently selected from -O-, -S- or -Se-; Y is selected from ClO4 - 、Cl - Br - , I - PF6 - 、BF4 - 、CH3COO - CF3COO - 、CH3SO3 - or CF3SO3 - ; Z is selected from -NH-, -O-, -S- or -Se-; R is selected from the following formula (1-1) or formula (1-2): In formula (1-1), R5, R6, and R7 are the same or different and are independently selected from -H, -C 1-8 Alkyl, -halogen, -halogenated C 1-8 Alkyl, -OH, -OC 1-8 Alkyl, -NO2, -CN, -NH2, -NH-C 1-8 Alkyl, -N(C 1-8 Alkyl)2, -COOH, -C 1-8 Alkyl-COOH, -CO-OC 1-8 Alkyl, -SO3H, -SO3-C 1-8 alkyl; In formula (1-2), m is selected from 1, 2 or 3; n is selected from an integer between 0 and 60; p is selected from 1, 2 or 3; the connecting group M is selected from -O-, -NH-, -COO-, -OCO-, -CONH-, -NHCO-; the terminal group T is selected from -H, -C 1-8 Alkyl, -OH, -OC 1-8 Alkyl, -SH, -SO3H, -COOH, -COOC 1-8 alkyl.

2. The compound according to claim 1, characterized in that R1 and R2 are the same or different and are independently selected from -H, -CH3, -C2H5, -F, -Cl, -Br, -I, -CF3, -OH, -OCH3, -OC2H5, -N(CH3)2, -N(C2H5)2, -NO2, -CN, -COOH, -CH2COOH, -COOCH3, -SO3H; and / or, R3 and R4 are the same or different and are independently selected from -H, -CH3, -C2H5, phenyl; And / or, Y is selected from ClO4 - Br - , I - PF6 - 、BF4 - CF3COO - 、CH3SO3 - or CF3SO3 - ; And / or, in formula (1-1), R5, R6, and R7 are the same or different and are independently selected from -H, -CH3, -C2H5, -F, -Cl, -Br, -I, -CF3, -OH, -OCH3, -OC2H5, -NO2, -CN, -N(CH3)2, -N(C2H5)2, -COOH, -CH2COOH, -COOCH3, -COOC2H5, and -SO3H; And / or, in formula (1-2), the terminal group T is selected from -H, -OH, -OC 1-6 Alkyl, -SH, -SO3H, -COOH, -COOC 1-6 alkyl.

3. The compound according to claim 1, characterized in that In formula (1-2), the terminal group T is selected from -H, -OH, -COOH, -SO3H, and -OCH3.

4. The compound according to claim 1, characterized in that The compound represented by formula (1) has the structure shown below CL1-CL31:

5. A method for synthesizing the compound according to any one of claims 1 to 4, comprising the steps of: reacting intermediate IV with R-ZH to obtain a compound of formula (1); in, R, R1, R2, R3, R4, X, Y, and Z independently have the meanings as described in any one of claims 1 to 4; The reaction is carried out in the presence of a base.

6. The synthesis method according to claim 5, characterized in that The base is selected from one or more of triethylamine, pyridine, piperidine, N,N-diisopropylethylamine, potassium carbonate, sodium carbonate, cesium carbonate, potassium hydroxide, and sodium hydroxide.

7. Use of the compound according to any one of claims 1 to 4 in the preparation of a photosensitizer or a photothermal agent.

8. Use of the compound according to any one of claims 1 to 4 in the preparation of a biological imaging agent.

9. The use according to claim 8, characterized in that The biological imaging agent is selected from a vascular imaging agent or a tumor fluorescence guided imaging agent.

10. The use according to claim 8, characterized in that The biological imaging agent is a tumor blood vessel imaging agent.

11. The use according to claim 8, characterized in that The imaging includes fluorescence imaging of cells and biological tissues in the near-infrared region II, blood vessel imaging in the near-infrared region II, and organ imaging in the near-infrared region II.

12. The use according to claim 8, characterized in that The imaging is near-infrared zone II tumor vascular imaging.

13. Use of the compound according to any one of claims 1 to 4 in the preparation of an anti-tumor, anti-bacterial, anti-fungal or anti-inflammatory agent.

14. A bioimaging agent, a fluorescent diagnostic agent, a photodynamic agent and / or a photothermal agent, comprising the compound according to any one of claims 1 to 4. The reagent according to claim 13 , further comprising fetal bovine serum or high molecular weight polymer F127.

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