PSMA-targeted polysaccharide drug conjugate as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of biological medicine, and relates to a PSMA-targeted polysaccharide drug conjugate as well as a preparation method and application thereof. The structure is shown in the specification, or an isomer or a derivative thereof, or pharmaceutically acceptable salts or solvates thereof. . The polysaccharide drug conjugate provided by the invention has high anti-tumor activity and safety, the toxicity of the taxane compound is greatly reduced, and the tolerance dose of the drug can be increased.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology and relates to polysaccharide drug conjugates targeting PSMA, their preparation methods, and applications. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Prostate-specific membrane antigen (PSMA) is a type II transmembrane glycoprotein composed of 751 amino acids with a molecular weight of approximately 100 kDa. Its structure includes a short N-terminal intracellular region (19 amino acids), a transmembrane region (24 amino acids), and a large C-terminal extracellular region (708 amino acids). The C-terminal extracellular region contains a catalytically active site belonging to the M28 family of metalloproteinases and exhibiting glutamate carboxypeptidase activity.

[0004] PSMA is expressed at low levels in normal prostate epithelial cells, primarily located in the plasma membrane and intracellular portion of epithelial cells. However, in prostate cancer cells, PSMA expression is significantly upregulated, particularly in castration-resistant prostate cancer (CRPC) and metastatic castration-resistant prostate cancer (mCRPC), where expression levels are typically higher. Furthermore, PSMA has also been found expressed in some non-prostate-derived tumors, such as renal cell carcinoma, bladder cancer, hepatocellular carcinoma, and certain types of gliomas. PSMA possesses gamma-glutamyl peptidase activity, hydrolyzing N-acetylaspartate-α-glutamylamine (NAAG) in the extracellular matrix to release glutamate, increasing free glutamate levels in the tumor microenvironment and thus promoting angiogenesis. Angiogenesis is crucial for rapid tumor growth and metastasis. PSMA can enhance tumor cell survival and tolerance to apoptosis by modulating signaling pathways in the tumor microenvironment, such as the PI3K / Akt and MAPK signaling pathways. PSMA is associated with cell adhesion and matrix degradation, promoting cancer cell penetration across the basement membrane and enhancing tumor invasiveness. Its enzymatic activity can regulate the activity of matrix metalloproteinases (MMPs), promote the degradation of the extracellular matrix, and make it easier for cancer cells to migrate to distant tissues. Due to the high expression of PSMA in tumors such as prostate cancer, and the close correlation between its expression level and the malignancy of the tumor, PSMA has become a key target for multiple targeted therapy strategies.

[0005] In recent years, PSMA-targeted therapy has achieved some breakthroughs, especially in the field of targeted small-molecule radionuclide therapy. 2-[3-(1,3-dicarboxypropyl)ureo]glutaric acid (DUPA) is a small-molecule PSMA ligand that has become a promising candidate for designing novel PSMA-targeted radiopharmaceuticals due to its high affinity and specific binding ability to prostate-specific membrane antigen (PSMA). In 2022, the US FDA approved 177Lu-PSMA-617 (trade name Pluvicto) for the treatment of mCRPC patients, becoming the first approved PSMA-targeted radiopharmaceutical. However, the toxicity and side effects of radiopharmaceuticals are a major drawback, requiring strict protective measures and high manufacturing standards, resulting in very high prices and significant inconvenience for patients. Furthermore, during radiopharmaceutical use, patients are restricted from contact with family members, impacting their quality of life. Alternatives to PSMA-targeted radiotherapy for tumors are currently being developed. Regarding the development of small-molecule PSMA-targeted tumor drugs, the literature has reported: 1) Small-molecule drug conjugates obtained by covalently coupling drugs (such as docetaxel) or toxins (such as MMAE) to DUPA via a linker arm, using DUPA and its derivatives as small-molecule PSMA ligands. Although these small-molecule drug conjugates show significant anti-tumor effects in animals, their molecular weight is below 5000, they are rapidly excreted by the kidneys, and have a very short half-life in vivo. 2) PMSA protein degrading agents (PROTACs) designed based on DUPA small-molecule ligands. To date, as a new type of drug, protein degrading agents have only a few precedents of approval for marketing.

[0006] In the development of macromolecular targeted therapies for PSMA tumors, the main approaches are antibodies such as J591 and D2B, and antibody-drug conjugates (ADCs) such as MLN2704, PSMA-MMAE, MEDI3726, and ARX517. While two antibodies and three PSMA antibody-drug conjugates have been reported in the literature, they failed in clinical trials due to severe toxicity. To date, no macromolecular antibodies or ADCs have been approved for marketing for targeted therapy of PSMA tumors. Furthermore, both antibodies and ADCs are large molecules with poor penetration into solid tumors and exhibit antigenicity, leading to a high risk of drug resistance.

[0007] In summary, PSMA-targeted therapy still faces challenges, such as drug resistance and treatment-related toxicities, necessitating the development of novel, highly effective, and low-toxicity therapies targeting PSMA-related tumors. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a polysaccharide drug conjugate targeting PSMA, its preparation method, and its application.

[0009] This invention demonstrates through a series of experiments that the polysaccharide-PSMA ligand-taxane (or with added lipid compound units) conjugate of general formula I is an effective drug for targeted therapy of PSMA tumors. The general formula I structure can optionally consist of six parts: a modified or unmodified polysaccharide, a taxane drug and a structurally similar compound, an unsaturated fatty acid unit, a PSMA ligand, a linker arm, and a spacer group, with an average molecular weight of 1.0k to 1000k Daltons. The mechanism of action of Formula I: A dual-drug conjugate of a large polymer polysaccharide (especially dextran) (or a modified glutamate fragment carrying a negative charge in the blood) is non-antigenic, thus rarely exhibiting the "protein crown phenomenon" where it is recognized as a foreign substance by immune cells, a common problem with traditional nanomedicines. It is not rapidly cleared by the reticuloendothelial system, thus avoiding accumulation in the liver and spleen, significantly reducing hepatotoxicity, a major cause of antitumor drug failure. The Formula I dual-drug conjugate also accumulates in tumor tissue through its leakage and retention effect (commonly known as the "EPR effect"). The PSMA ligand in Formula I actively binds to the PSMA protein of tumor cells, further enriching the drug in tumor tissue. Once inside tumor cells, under enzymatic catalysis, dextran is completely degraded into small glucose molecules, allowing one or two drugs with different mechanisms of action, including taxanes and structurally similar compounds such as docetaxel or cabazitaxel, along with unsaturated fatty acids like gamma-linolenic acid, to be fully released. Gamma-linolenic acid (GLA) has a synergistic antitumor effect against docetaxel or cabazitaxel without increasing the toxicity of docetaxel or cabazitaxel to normal cells. Furthermore, some PSMA tumors exhibit macropinocytosis activity, actively phagocytosing bivalent conjugates for highly efficient intracellular entry. This efficiency in penetrating the cell is a characteristic not found in other types of antitumor drugs such as antibody-drug conjugates (ADCs), small molecule kinase inhibitors, and peptides.

[0010] To achieve the above objectives, the present invention provides the following technical solution: In the first aspect, a polysaccharide drug conjugate targeting PSMA has the structure shown in general formula I, or its isomers or derivatives, or pharmaceutically acceptable salts or solvates thereof.

[0011] General Formula I Among them, spacer 4, linker arm 3, or target PSMA ligand are covalently linked to the polysaccharide binding site of the polysaccharide, and spacer 4, linker arm 3 and target PSMA ligand are covalently linked. Spacer 1, linker arm 1, branched structural unit, spacer 2, linker arm 2, or taxane compound are covalently linked to the polysaccharide binding site of the polysaccharide. Spacer 1, linker arm 1, branched structural unit, spacer 2, linker arm 2 are covalently linked to the taxane compound, and branched structural unit, spacer 3, and unsaturated fatty acid unit are covalently linked. The covalent bonds are selected from amide bonds, carbamate bonds, aminothiocarbamate bonds, ester bonds, isourea bonds, thiourea bonds, urea bonds, disulfide bonds, carbonate bonds, phosphate ester bonds, phosphoamide bonds, sulfonamide bonds, α-glycosidic bonds, β-glycosidic bonds, and triazole-containing covalent bonds.

[0012] In some embodiments, the polysaccharide binding site is selected from the hydroxyl, carboxyl, amino, phosphate, and sulfonic acid groups of the polysaccharide.

[0013] In some embodiments, the polysaccharide is selected from dextran, levtran, hyaluronic acid, cyclodextrin (α, β, or γ), hydroxyethyl starch, xylan, polysialic acid, Ganoderma lucidum polysaccharide, lentinan, and amylose, and the molecular weight of the polysaccharide ranges from 0.3k to 3000k Daltons; preferably, it is dextran. Dextran is a high molecular weight polymer formed by glucose condensation, which has the characteristics of good water solubility, biodegradability, high biocompatibility with human tissues, non-immunogenicity, and good safety. It is widely used in clinical practice as a blood volume expander and as a drug carrier. Dextran can deliver drugs through physical encapsulation or chemical coupling, and the conjugates generated by chemical coupling are more stable than those generated by physical encapsulation. In addition, dextran-carrier nanoparticles are less likely to form protein corona in plasma, which can better avoid clearance by the mononuclear macrophage system and complement system, and prolong the half-life. Polymer dextran exhibits superior permeability and retention in tumor tissues (commonly known as the "EPR" effect), leading to its enrichment at tumor sites. Furthermore, it can be efficiently concentrated within tumor cells through macropinocytosis, resulting in excellent tumor-targeting enrichment. Therefore, using dextran as a drug carrier, combined with ligands targeting PSMA, allows for precise drug delivery to PSMA-affected tumor tissues, demonstrating promising clinical application value.

[0014] In some embodiments, the polysaccharide is a modified polysaccharide or an unmodified polysaccharide. Specifically, the modified polysaccharide contains a glutamic acid fragment. More specifically, the modifying group is... .

[0015] In some embodiments, connecting arm 1, connecting arm 2, and connecting arm 3 are each independently selected from the following structures: disubstituted C 5-20 Alkyl, C 5-20 cycloalkyl, C 5-20 Heterocyclic alkyl, C 5-20 alkenyl, C5-20 alkynyl group, C 6-20 Aryl or C 5-20 A heteroaryl group, a disubstituted peptide containing 3 to 10 natural or non-natural amino acids, a polyethylene glycol chain with a molecular weight of 300 to 5000, or a combination thereof; the natural amino acids are selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, or derivatives thereof; the non-natural amino acids are selected from D-alanine, D-arginine, D-asparagine, D-cysteine, D-glutamic acid, D-glutamine, D-histidine, D-isoleucine, D-leucine, D-lysine, D-methionine, D-phenylalanine, D-proline, D-serine, D-threonine, D-tryptophan, D-tyrosine, D-valine, NH2(CH2). 2-10 COOH or its derivatives.

[0016] In some embodiments, the taxanes are selected from natural or semi-synthetic compounds and their derivatives with taxane diterpenoids as the parent nucleus; preferably cabazitaxel or docetaxel.

[0017] In some embodiments, the molar ratio of the taxane compound to the targeting PSMA ligand or unsaturated fatty acid unit is arbitrary, preferably 0.1 to 10. The linker site of the taxane compound is located on the side chain at the 2'-O position of the taxane compound.

[0018] In some embodiments, the unsaturated fatty acid unit is a single molecule of unsaturated fatty acid or a structural unit composed of multiple identical or different single molecules of unsaturated fatty acids. Specifically, the single molecule lipid compound is selected from unsaturated fatty acids DHA, EPA, and GLA.

[0019] In some embodiments, spacer 1, spacer 2, spacer 3, and spacer 4 are each independently selected from the following structures: disubstituted C 1-10 Alkyl, C 3-10 cycloalkyl, C 3-10 Heterocyclic alkyl, C 3-10 alkenyl, C 3-10 alkynyl group, C 6-10 Aryl or C 5-10Heteroaryl groups, natural or non-natural amino acids, disubstituted peptides containing 2 to 3 natural or non-natural amino acids, polyethylene glycol chains with a molecular weight of 100 to 500, or combinations thereof; natural amino acids are selected from alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, or derivatives thereof; non-natural amino acids are selected from D-alanine, D-arginine, D-asparagine, D-cysteine, D-glutamic acid, D-glutamine, D-histidine, D-isoleucine, D-leucine, D-lysine, D-methionine, D-phenylalanine, D-proline, D-serine, D-threonine, D-tryptophan, D-tyrosine, D-valine, NH2(CH2). 2-10 COOH or its derivatives; In some embodiments, the branched structural unit is a trisubstituted structure with a length of 6 to 100 atoms, selected from linear alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, heteroaryl or derivatives thereof.

[0020] Specifically, the branch structure unit is selected from the following structures: .

[0021] In some implementations, the following structures are selected:

[0022]

[0023]

[0024] .

[0025] In some implementation schemes, couplings 30, 31, 32, and 33 are selected.

[0026] In a second aspect, a pharmaceutical composition includes an active ingredient and a pharmaceutical carrier, wherein the active ingredient is the aforementioned polysaccharide drug conjugate targeting PSMA.

[0027] In some embodiments, the polysaccharide drug conjugate targeting PSMA contains 0.1% to 60% by weight of taxane compounds.

[0028] The polysaccharide drug conjugates or pharmaceutical compositions of this invention can be administered in unit doses via enteral or non-enteric routes, such as oral, intramuscular, subcutaneous, nasal, oral mucosa, skin, peritoneum, rectum, etc. The polysaccharide drug conjugates or pharmaceutical compositions of this invention can also be administered by injection. Injection includes intravenous injection, intramuscular injection, subcutaneous injection, intradermal injection, and acupoint injection. The dosage form of the polysaccharide drug conjugates or pharmaceutical compositions of this invention can be a liquid dosage form or a solid dosage form. Liquid dosage forms include true solutions, colloids, microparticles, emulsions, and suspensions. Other dosage forms include tablets, capsules, pellets, aerosols, pills, powders, solutions, suspensions, emulsions, granules, suppositories, and lyophilized powder injections. The polysaccharide drug conjugates or drug compositions described in this invention can be formulated into conventional formulations, sustained-release formulations, controlled-release formulations, targeted formulations, and various microparticle delivery systems, such as lyophilized powders, injections, sustained-release formulations, controlled-release formulations, tablets, capsules, pills, and various nanoparticle formulations.

[0029] The pharmaceutical carriers described in this invention can be binders, wetting agents, diluents, absorbents, disintegrants, disintegration inhibitors, absorption promoters, lubricants, preservatives, surfactants, dispersants, solubilizers, buffers, pH adjusters, fragrances, flavoring agents, sweeteners, etc. The pharmaceutical carriers may vary depending on the formulation and dosage form. To formulate the polysaccharide drug conjugate or pharmaceutical composition into tablets, the pharmaceutical carriers that can be used include: diluents and absorbents, such as sucrose, lactose, glucose, starch, dextrin, kaolin, aluminum silicate, urea, calcium carbonate, calcium sulfate, microcrystalline cellulose, sodium chloride, mannitol, etc.; wetting agents and binders, such as water, glycerin, polyethylene glycol, ethanol, propanol, polyvinylpyrrolidone, dextrin, syrup, honey, glucose solution, gelatin paste, sodium carboxymethyl cellulose, starch paste, gum arabic paste, etc. Tablets can be formulated with various materials such as gums, methylcellulose, and potassium phosphate; disintegrants, such as dried starch, alginate, agar powder, brown algae starch, sodium bicarbonate and citric acid, calcium carbonate, polyoxyethylene sorbitol fatty acid esters, sodium dodecyl sulfate, methylcellulose, and ethylcellulose; disintegration inhibitors, such as sucrose, tristearate, cocoa butter, and hydrogenated oil; absorption enhancers, such as quaternary ammonium salts and sodium dodecyl sulfate; and lubricants, such as corn starch, talc, silica, stearates, boric acid, liquid paraffin, and polyethylene glycol. Tablets can also be further formulated into coated tablets, such as film-coated tablets, sugar-coated tablets, enteric-coated tablets, or bilayer and multilayer tablets, in which case the drug carrier also includes the coating material. To formulate the aforementioned polysaccharide drug conjugates or pharmaceutical compositions into pills, the pharmaceutical carriers that can be used include: diluents and absorbents, such as starch, glucose, lactose, cocoa butter, hydrogenated vegetable oil, polyvinylpyrrolidone, kaolin, talc, etc.; binders, such as gum arabic, tragacanth, gelatin, ethanol, honey, liquid sugar, rice paste, or flour paste, etc.; disintegrants, such as agar powder, dried starch, alginate, sodium dodecyl sulfate, methylcellulose, ethylcellulose, etc. To formulate the aforementioned polysaccharide drug conjugates or pharmaceutical compositions into capsules, the active ingredient can be mixed with various carriers, and the resulting mixture can be placed in hard gelatin capsules or soft capsules. Alternatively, the active ingredient can be formulated as microcapsules, suspended in an aqueous medium to form a suspension, or filled into hard capsules or formulated as an injectable preparation. The aforementioned polysaccharide drug conjugates or pharmaceutical compositions are formulated into injectable preparations, such as solutions, suspension solutions, emulsions, and lyophilized powder injections. These preparations can be aqueous or non-aqueous, and the pharmaceutical carriers that can be used include diluents, binders, lubricants, preservatives, surfactants, or dispersants. The diluents can be selected from water, ethanol, polyethylene glycol, 1,3-propanediol, ethoxylated isostearyl alcohol, polyoxyethylene isostearyl alcohol, polyoxyethylene sorbitan fatty acid esters, etc. Furthermore, to prepare isotonic injections, appropriate amounts of sodium chloride, glucose, sucrose, or glycerol can be added to the injectable formulation. In addition, conventional solubilizers, buffers, pH adjusters, etc., can also be added.These excipients are commonly used in the field. In addition, colorants, preservatives, flavorings, tasters, sweeteners or other materials may be added to pharmaceutical preparations if necessary.

[0030] Thirdly, the use of the above-mentioned polysaccharide drug conjugate or drug composition targeting PSMA in the preparation of a drug for treating PSMA tumors.

[0031] To achieve the intended therapeutic effect, the polysaccharide drug conjugate or pharmaceutical composition of this invention can be administered using any known method of administration. The dosage of the polysaccharide drug conjugate or pharmaceutical composition of this invention depends on many factors, such as the nature and severity of the disease to be prevented or treated, the sex, age, weight, personality, and individual response of the patient or animal, the route of administration, frequency of administration, and therapeutic purpose. Therefore, the therapeutic dosage of the polysaccharide drug conjugate or pharmaceutical composition of this invention can vary widely. Generally, the dosage of the pharmaceutical components used in this invention is known to those skilled in the art. The actual amount of drug contained in the final formulation of the polysaccharide drug conjugate or pharmaceutical composition of this invention can be appropriately adjusted to achieve the required therapeutic dose and fulfill the preventive or therapeutic purpose of this invention. The preferred dosage range for the conjugate drug of this invention is 1.0–2000 mg / kg body weight per day, every 2 days, every 3 days, every week, every 2 weeks, or every 3 weeks. The above dosage can be administered as a single dose or divided into several doses, such as two, three, or four doses, depending on the clinical experience of the attending physician and the dosing regimen, including the use of other treatment methods. The total dose required for each treatment can be divided into multiple doses or administered as a single dose. The polysaccharide drug conjugates or pharmaceutical compositions described in this invention can be used alone or in combination with other therapeutic agents and the dosage can be adjusted.

[0032] The subjects or patients of the drug for treating PSMA tumors according to the present invention can be animals (e.g., non-human animals), vertebrates, mammals, rodents (e.g., guinea pigs, hamsters, rats, mice), murines (e.g., mice), canines (e.g., dogs), felines (e.g., cats), equines (e.g., horses), primates, apes (e.g., monkeys and apes), monkeys (e.g., rhesus monkeys, marmosets, baboons), apes (e.g., gorillas, chimpanzees, orangutans, gibbons), or humans. Preferably, the subject / patient is a mammal; more preferably, the subject / patient is a human.

[0033] The PSMA tumor described in this invention can be a tumor capable of expressing PSMA, wherein the tumor can be one or more of prostate cancer, renal cell carcinoma, bladder cancer, hepatocellular carcinoma, glioma, etc. Preferably, the PSMA tumor is prostate cancer.

[0034] Fourthly, a method for treating PSMA tumors, comprising administering the aforementioned PSMA-targeting polysaccharide drug conjugate or drug composition to a subject or patient.

[0035] The subject or patient may be an animal (e.g., a non-human animal), a vertebrate, a mammal, a rodent (e.g., a guinea pig, hamster, rat, mouse), a murine (e.g., mouse), a canine (e.g., dog), a feline (e.g., cat), an equine (e.g., horse), a primate, ape (e.g., monkey and ape), a monkey (e.g., rhesus macaque, marmoset, baboon), an ape (e.g., gorilla, chimpanzee, orangutan, gibbon), or a human. Preferably, the subject / patient is a mammal; more preferably, the subject / patient is a human.

[0036] When administered, the actual amount of drug contained in the final formulation of the polysaccharide drug conjugate or pharmaceutical composition according to the present invention can be appropriately adjusted to achieve the required therapeutic dose and accomplish the preventive or therapeutic purpose of the present invention. The preferred dosage range for the conjugate drug of the present invention is 1.0 to 2000 mg / kg body weight per day, every two or three days, every week, every two or three weeks. The above dosage can be administered as a single dose or divided into several doses, such as two, three, or four doses, depending on the clinical experience of the administering physician and the dosing regimen, including the use of other treatment methods. The total dose required for each treatment can be divided into multiple doses or administered as a single dose. The polysaccharide drug conjugate or pharmaceutical composition of the present invention can be used alone or in combination with other therapeutic drugs with adjusted dosages.

[0037] The treatment described in this invention refers to a method performed to obtain a beneficial or desired clinical outcome. For the purposes of this application, a beneficial or desired clinical outcome includes, but is not limited to, alleviating symptoms, reducing the extent of disease, stabilizing (i.e., no longer worsening) the state of disease, delaying or slowing the progression of disease, improving or alleviating the state of disease, and relieving symptoms (whether partial or complete), whether detectable or undetectable. Furthermore, "treatment" can also mean prolonging survival compared to the expected survival (if no treatment was received).

[0038] The therapeutically effective amount described in this invention refers to an amount of polysaccharide drug conjugates or pharmaceutical compositions, including the compounds of this invention, that can elicit a biological or medical response in an tissue system, animal, or human as sought by researchers, veterinarians, physicians, or other medical personnel, including the reduction or partial reduction of symptoms of the treated disease, syndrome, symptom, or disorder.

[0039] The beneficial effects of this invention are as follows: The polysaccharide drug conjugate provided by this invention not only lacks antigenicity, significantly reducing hepatotoxicity and ensuring antitumor activity, but also exhibits leakage and retention effects, and can bind to PSMA proteins on tumor cells, thus achieving tumor tissue targeting. Furthermore, after entering tumor cells, it releases taxanes and unsaturated fatty acids through enzymatic hydrolysis, thereby achieving a synergistic antitumor effect. In addition, for PSMA tumors with macropinocytosis activity, it can increase the efficiency of cell entry, thereby improving efficacy. Animal experiments have shown that the polysaccharide drug conjugate provided by this invention has high antitumor activity and safety, significantly reduces the toxicity of taxanes, and can increase the tolerable dose of the drug. Attached Figure Description

[0040] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0041] Figure 1 The following are fluorescence intensity diagrams of the fluorescent conjugate in nude mouse tumors with 22Rv1 xenografts at different time points in embodiments of the present invention, wherein *P<0.05, **P<0.01, ***P<0.001, and ****P<0.0001; Figure 2 The figure shows the effect of the coupling agent on the tumor volume of 22Rv1 tumor-bearing nude mice in this embodiment of the invention, where *P<0.05, **P<0.01, ***P<0.001, n=6; Figure 3 The figure shows the effect of the coupling agent on the body weight of 22Rv1 tumor-bearing nude mice in this embodiment of the invention, where **P<0.01, n=6; Figure 4 The figure shows the effect of the conjugate on the tumor volume of PC-3 / PSMA-bearing nude mice in this embodiment of the invention, where *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001, n=6; Figure 5 These are tumor photographs of PC-3 / PSMA-bearing nude mice three weeks after administration of the conjugate in this embodiment of the invention. Figure 6 The figure shows the effect of the coupling agent on the body weight of PC-3 / PSMA tumor-bearing nude mice in this embodiment of the invention, where P < 0.0001 and n = 6. Detailed Implementation

[0042] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0043] Synthesis Route 1

[0044] Example 1: Synthesis of Compound 1 In a 500 mL round-bottom flask, Boc-Lys(N3)-OH (30.0 g, 110 mmol), HOBt (25.4 g, 165 mmol), and HBTU (62.6 g, 165 mmol) were added, followed by 100 mL of anhydrous DMF and stirring at room temperature for 30 minutes. Then, 31.0 mL of triethylamine (220 mmol) was added dropwise. After stirring for 30 minutes, 200 mL of anhydrous ethanol was added. The reaction was stirred overnight at room temperature. After the reaction was complete, the reaction mixture was concentrated and partitioned in ethyl acetate (250 mL) and brine (250 mL). The organic phase was washed twice with brine (200 mL × 2), dried over anhydrous sodium sulfate, filtered, concentrated, and purified by elution with ethyl acetate / petroleum ether (5-60%) on a silica gel column to give 22.3 g of compound 1. Yield: 57%.

[0045] NMR analysis: 1 H NMR (300 MHz, CDCl3): δ 5.03 (d, J = 6.0 Hz, 1H), 4.31 (m,1H), 4.20 (m,2H), 3.29 (t, J = 6.8 Hz, 2H), 1.83 (m,1H), 1.72 - 1.56 (m, 4H),1.47 (s, 10H), 1.28 (t, J = 6.6 Hz, 3H). Mass spectrometry analysis: ESI-MS ( m / z ): calcd for C 13 H 25 N4O4[M+H] + : 301.18; found:301.19. Example 2: Synthesis of Compound 2 In a 500 mL round-bottom flask, 11.3 g of compound 1 (37.6 mmol) was dissolved in 100.0 mL of hydrochloric acid-ethanol solution (4.0 N), and the mixture was stirred at room temperature for 1 hour. After concentration, the reaction mixture was purified by elution with methanol / chloroform (0–8%) on a silica gel column to give 8.93 g of compound 2. Yield: 100%.

[0046] NMR analysis: 1H NMR (600 MHz, CDCl3): δ 4.20 (m, 2H), 3.50(t, J = 6.0 Hz, 1H), 3.29 (t, J = 7.2 Hz, 2H), 1.78 (m, 1H), 1.67 - 1.58 (m, 3H), 1.51 - 1.45(m, 2H), 1.27 (t, J = 7.2 Hz, 3H). Mass spectrometry analysis: ESI-MS ( m / z ): calcd for C8H 17 N4O2[M+H] + : 201.13; found:201.15. Example 3: Synthesis of Compound 3 In a 500 mL round-bottom flask, compound 2 (10.5 g, 52.2 mmol) was dissolved in 200 mL of anhydrous dichloromethane and 25.0 mL of pyridine, and cooled to 0 °C under nitrogen protection. o C, then diphosgene (12.5 g, 63.0 mmol) in dichloromethane was slowly added and the mixture was stirred for 3 hours. The reaction mixture was diluted to DCM (300 mL) and washed three times (150 mL × 3) with 1.0 N hydrochloric acid solution, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to give compound 3 (7.83 g). Yield: 67%. This compound was used directly in the next step without further purification.

[0047] NMR analysis: 1 H NMR (300 MHz, CDCl3): δ 4.26 (q, J = 7.2 Hz, 2H), 4.03 (dd, J = 4.4 Hz, 1H), 3.31 (t, J = 6.8 Hz, 2H), 1.92 - 1.69 (m, 2H), 1.64 - 1.57 (m,2H), 1.53 - 1.44 (m, 2H), 1.31 (t, J = 6.8 Hz, 3H), 1.24 (s, 1H). Mass spectrometry analysis: MS (ESI, m / z ): calcd for C9H 18 N5O3[M+NH4] + : 244.14; found:244.69. Example 4: Synthesis of bifunctional dextran 4a 50.0g of dextran with an average molecular weight of 100k Daltons at 60 o Drying in an oil bath at high vacuum for 10 hours, followed by drying at 60°C. o The compound was dissolved in 250.0 mL of anhydrous DMSO at temperature C, and then the solution was cooled to room temperature and the oil bath was removed. Dimethyl (S)-2-isocyanoglutarate (26.0 g, 129.2 mmol), compound 3 (7.0 g, 30.9 mmol), and DMAP (6.5 g, 58.0 mmol) were slowly added to the above solution, and the mixture was stirred overnight at room temperature. After the reaction was complete, the reaction mixture was directly placed into a dialysis bag with a molecular weight cutoff of 10,000 Daltons and dialyzed against running water for 24 hours. After concentration, it was hydrolyzed with NaOH (10.0 g, 250.0 mmol) for 5 hours. The reaction solution was adjusted to pH 3.0–5.0 with 4.0 N hydrochloric acid solution, dialyzed three times in one step, concentrated, and lyophilized to give bifunctionalized dextran 4 (41.5 g). Yield: 83%.

[0048] NMR analysis: 1 H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ 4.50 - 5.00 (m, CHO), 3.30 - 4.00 (m, CHOH, CH2OH); minor signals: δ 2.29 - 1. 70 (m), 1.56 - 1.39 (m), 1.28 (s, CH3). Example 5: Synthesis of bifunctional dextran 4b The preparation method of bifunctional dextran 4b is similar to that of bifunctional dextran 4a. 50.0 g of dextran with an average molecular weight of 70 kDaltons was used as the starting material, and dialysis was performed using a dialysis bag with a molecular weight cutoff of 10,000 Daltons to obtain 45.7 g of bifunctional dextran 4b. Yield: 91%.

[0049] NMR analysis: 1H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ 4.50 - 5.00 (m, CHO), 3.30 - 4.00 (m, CHOH, CH2OH); minor signals: δ 2.29 - 1. 70 (m), 1.56 - 1.39 (m), 1.28 (s, CH3). Synthesis Route 2

[0050] Example 6: Synthesis of Compound 5 4-Pentynic acid (4.0 g, 40.78 mmol), EDCI (11.7 g, 61.4 mmol), and NHS (7.04 g, 61.2 mmol) were dissolved in 60 mL of anhydrous dichloromethane and stirred at room temperature for 3 h. After the reaction was complete, the reaction system was diluted with dichloromethane, the organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain a pale yellow oil (10.1 g, 51.2 mmol), which was 4-pentynic acid NHS-ester. Nα-Boc-L-lysine (19.0 g, 76.8 mmol) was dissolved in 60 mL of anhydrous DMF, and triethylamine (10.8 mL, 76.8 mmol) was added. The mixture was stirred at room temperature for 30 min, and then the 4-pentynic acid-NHS-ester prepared above was added to the reaction system. The mixture was stirred at room temperature for another 3 h. After the reaction was complete, the pH of the reaction system was adjusted to 3.0-4.0 with 1N HCl solution. The mixture was then partitioned in saturated brine and ethyl acetate. The organic layer was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated, and purified on a silica gel column (eluent: methanol:dichloromethane / 2-7% MeOH) to give 13.2 g of compound 5. Yield: 80%.

[0051] NMR analysis: 1 H NMR (300MHz, DMSO-d6): δ12.42(s, 1H), 7.86(t, J=5.6Hz, 1H), 7.01(d, J=8.0Hz, 1H), 3.82(m, 1H), 3.02(q, J=6.3Hz, 2H), 2.73(t, J =2.6Hz,1H), 2.37–2.31(m, 2H), 2.27–2.21(m, 2H), 1.66–1.49(m, 2H), 1.38(s, 9H), 1.35(d, J=4.7Hz, 2H), 1.30(m, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 16 H 26 N2O5[MH] - : 325.17; found:325.27. Example 7: Synthesis of Compound 6 Compound 5 (12.0 g, 37.0 mmol) was dissolved in 50 mL of 3.0 N hydrochloric acid-ethanol solution and stirred at room temperature for 2 h. After the reaction was complete, the solution was evaporated to dryness and purified by silica gel column chromatography (eluent: methanol:dichloromethane / 2 - 30%) to give 7.3 g of compound 6. Yield: 85%.

[0052] NMR analysis: 1 H NMR (300MHz, DMSO-d6): δ8.50(s, 3H), 8.06(t, J=5.6Hz, 1H), 3.86–3.78(m, 1H), 3.03(q, J=6.3Hz, 2H), 2.77(t, J=2.5Hz, 1H), 2.41–2.31(m,2H), 2.27(m, 2H), 1.86–1.73(m, 2H), 1.47–1.22(m, 4H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 11 H 18 N₂O₃[M+H] + : 227.13; found:227.12. Example 8: Synthesis of Compound 7 GLA (3.0 g, 10.8 mmol), EDCI (6.2 g, 32.5 mmol), and NHS (3.8 g, 32.5 mmol) were dissolved in 40 mL of anhydrous dichloromethane and stirred at room temperature for 3 h. After the reaction was complete, the reaction system was diluted with dichloromethane, washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain 2.8 g of colorless oil, which was the GLA-NHS ester. Compound 6 (5.0 g, 22.2 mmol) was dissolved in 60 mL of DMF, and triethylamine (10.5 mL, 74.0 mmol) was added. The mixture was stirred at room temperature for 1 h, and then the GLA-NHS ester prepared above was added. The mixture was stirred at room temperature for 3 h. After the reaction was complete, the pH of the reaction system was adjusted to 3.0-4.0 with 1N HCl solution. Partitioning was performed in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. Purification was carried out on a silica gel column (eluent: methanol:dichloromethane / 2 - 11%) to give 6.53 g of compound 7. Yield: 90%.

[0053] NMR analysis: 1 HNMR(300MHz, DMSO-d6): δ5.40–5.27(m, 6H), 4.17–4.10(m, 1H),3.05–2.98(m, 2H), 2.78(t, J =5.8Hz, 4H), 2.73(t, J =2.6Hz, 1H), 2.34(td, J =6.8,4.0Hz, 2H), 2.27–2.22(m, 2H), 2.12(td, J =7.2, 1.9Hz, 2H), 2.08–1.99(m, 4H), 1.60–1.44(m, 4H), 1.33–1.25(m, 10H), 0.88–0.84(m, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 29 H 46 N2O4[MH] - : 485.34; found:485.41. Example 9: Synthesis of Compound 8 Glycine methyl ester hydrochloride (4.6 g, 37.0 mmol) was dissolved in 30 mL of anhydrous DMF, and triethylamine (7.0 mL, 49.5 mmol) was added. The mixture was stirred at room temperature for 1 h. Then, compound 7 (6.0 g, 12.3 mmol), EDCI (4.8 g, 24.6 mmol), and HOBt (3.4 g, 24.6 mmol) were added to the reaction mixture, and the mixture was stirred overnight at room temperature. After the reaction was complete, the reaction mixture was partitioned in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The purified phase was then purified by silica gel column chromatography (eluent: methanol:dichloromethane / 2 - 8%) to give 6.07 g of compound 8. Yield: 91%.

[0054] NMR analysis: 1 H NMR (600MHz, DMSO-d6): δ8.31(t, J =5.9Hz, 1H), 7.90(d, J =8.2Hz, 1H), 7.84(t, J =5.6Hz, 1H), 5.42–5.25(m, 6H), 4.25(m, 1H), 3.91–3.74(m,2H), 3.62(s, 3H), 3.01(qd, J =6.8, 2.7Hz, 2H), 2.78(t, J =5.8Hz, 4H), 2.74(d, J =2.5Hz, 1H), 2.39–2.29(m, 2H), 2.28–2.19(m, 2H), 2.13(m, 2H), 2.03(q, J =7.2Hz,4H), 1.68–1.58(m, 1H), 1.55–1.43(m, 3H), 1.41–1.34(m, 2H), 1.33–1.21(m, 10H),0.88–0.82(m, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 32 H 51 N3O5[M+H] + : 558.39; found:558.96. Example 10: Synthesis of Compound 9 Compound 8 (6.0 g, 10.76 mmol) was dissolved in 10 mL of methanol, and 50 mL of 3.0 N NaOH solution was added dropwise. The reaction was carried out at room temperature for 1 h. After the reaction was complete, the pH of the reaction system was adjusted to 3.0–4.0 with 1 N HCl solution. Partitioning was performed in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. Purification was performed on a silica gel column (eluent: methanol:dichloromethane / 2–20%) to give 5.6 g of compound 9. Yield: 95%.

[0055] NMR analysis: 1 HNMR(300MHz, DMSO-d6): δ7.98(d, J =8.2Hz, 1H), 7.88(m, 2H),5.43–5.26(m, 6H), 4.23(m, 1H), 3.61(t, J =4.8Hz, 2H), 3.00(m, 2H), 2.78(s, 4H),2.74(t, J =2.6Hz, 1H), 2.34(tt, J =7.4, 1.5Hz, 2H), 2.24(m, 2H), 2.14(h, J =6.8Hz,2H), 2.03(m, 4H), 1.68–1.57(m, 1H), 1.50(m, 3H), 1.40–1.35(m, 2H), 1.32–1.21(m, 10H), 0.88–0.82(m, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 31 H 49 N3O5[MH] - : 542.36; found:542.37. Example 11: Synthesis of Compound 10 Compound 9 (7.5 g, 13.8 mmol), DMAP (1.42 g, 23.0 mmol), and EDCI (4.41 g, 23.0 mmol) were dissolved in 50 mL of anhydrous DMF and stirred for 40 min. Then, cabazitaxel (CTX 9.6 g, 11.5 mmol) was dissolved in 50 mL of anhydrous DMF and added dropwise to the reaction mixture. The reaction was allowed to proceed overnight at room temperature. After the reaction was complete, the reaction system was partitioned in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The purified phase was then purified by silica gel column chromatography (eluent: ethyl acetate: petroleum ether / 30–90%) to give 6.13 g of compound 10. Yield: 41%.

[0056] NMR analysis: 1 H NMR (600MHz, DMSO-d6): δ8.40–8.32(m, 1H), 7.97(dd, J =8.8, 7.1 Hz, 2H), 7.84(t, J =5.7Hz, 1H), 7.73(m, 1H), 7.66(m, 2H), 7.47–7.29(m, 4H),7.19(t, J =7.3Hz, 1H), 5.84(t, J =9.1Hz, 1H), 5.38–5.29(m, 6H), 5.10(d, J =7.7Hz,2H), 4.98–4.90(m, 1H), 4.68(s, 1H), 4.52(s, 1H), 4.27(m, 1H), 4.04–3.96(m,3H), 3.74(dd, J =10.5, 6.7Hz, 1H), 3.58(d, J =7.1Hz, 1H), 3.28(s, 3H), 3.20(s,3H), 3.01(q, J =6.4Hz, 2H), 2.89(s, 1H), 2.77(t, J =5.8Hz, 3H), 2.75–2.72(m, 2H), 2.37–2.29(m, 2H), 2.28–2.19(m, 5H), 2.18–2.08(m, 2H), 2.03(m, 4H), 1.78(s,3H), 1.60(p, J =6.9Hz, 2H), 1.49(d, J=7.9Hz, 6H), 1.39(s, 9H), 1.33–1.22(m,13H), 0.98(d, J =7.6Hz, 6H), 0.85(t, J =6.8Hz, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 76 H 104 N4O 18 [M+H] + : 1361.74; found:1361.72. Synthesis Route 3

[0057] Example 12: Synthesis of Compound 11 Glycine methyl ester hydrochloride (3.42 g, 27.9 mmol) was dissolved in 30 mL of anhydrous DMF, and triethylamine (5.20 mL, 37.2 mmol) was added dropwise. The mixture was stirred at room temperature for 1 h. Then, compound 5 (3.0 g, 9.3 mmol), EDCI (3.6 g, 18.6 mmol), and HOBt (2.51 g, 18.6 mmol) were added to the reaction mixture, and the mixture was stirred overnight at room temperature. After the reaction was complete, the reaction mixture was partitioned in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The purified phase was then purified on a silica gel column (eluent: methanol:dichloromethane / 2 - 8%) to give 2.61 mg of compound 11. Yield: 72%.

[0058] NMR analysis: 1 H NMR (300MHz, DMSO-d6): δ8.22(t, J=5.9Hz, 1H), 7.85(t, J=5.6Hz, 1H), 6.83(d, J=8.2Hz, 1H), 3.95–3.75(m, 3H), 3.62(s, 3H), 3.09–2.95(m,2H), 2.74(t, J=2.6Hz, 1H), 2.35(td, J=7.6, 2.0Hz, 2H), 2.25(dd, J=7.8, 6.2Hz,2H), 1.65–1.44(m, 2H), 1.38(s, 11H), 1.31(s, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 19 H 31 N3O6[M+H] +: 398.22; found:398.21. Example 13: Synthesis of Compound 12 Compound 11 (2.5 g, 6.3 mmol) was dissolved in 30 mL of methanol, and 30 mL of 3.0 N NaOH solution was added dropwise. The reaction was carried out at room temperature for 1 h. After the reaction was complete, the pH of the reaction system was adjusted to 3.0–4.0 with 1 N HCl solution. The mixture was then partitioned in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The solution was purified by silica gel column chromatography (eluent: methanol:dichloromethane / 2–20%) to give 2.2 g of compound 12. Yield: 93%.

[0059] NMR analysis: 1 HNMR(300MHz, DMSO-d6): δ8.06(t, J=5.8Hz, 1H), 7.85(t, J=5.6Hz, 1H), 6.82(d, J=8.3Hz, 1H), 3.91(m, J=8.8, 4.8Hz, 1H), 3.83–3.65(m,2H), 3.01(dq, J=10.6, 3.6Hz, 2H), 2.75(t, J=2.6Hz, 1H), 2.37–2.32(m, 2H), 2.24(m, J=7.7, 6.2Hz, 2H), 1.65–1.43(m, 2H), 1.38(s, 11H), 1.30–1.21(m, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 18 H 29 N3O6[MH] - : 382.21; found:382.06. Example 14: Synthesis of Compound 13 The synthesis method of compound 13 is similar to that of compound 10.

[0060] NMR analysis: 1HNMR(600MHz, DMSO-d6): δ8.24(m, 1H), 7.97(m, 2H), 7.93–7.83(m, 2H), 7.77–7.71(m, 1H), 7.66(dd, J=8.2, 6.7Hz, 2H), 7.47–7.27(m, 4H), 7.19(t, J=7.4Hz, 1H), 6.86(d, J=8.5Hz, 1H), 5.84(t, J=9.1Hz, 1H), 5.37(d, J=7.0Hz, 1H), 5.13–5.06(m, 2H), 4.97–4.92(m, 1H), 4.68(s, 1H), 4.51(s, 1H),4.05–4.01(m, 2H), 3.62(s, 1H), 3.57(s, 1H), 3.27(s, 3H), 3.20(s, 3H), 3.01(q,J=6.5Hz, 2H), 2.89(s, 1H), 2.79–2.56(m, 4H), 2.34(m, 3H), 2.24(d, J=7.2Hz,4H), 1.77(s, 2H), 1.50(s, 4H), 1.38(d, J=3.4Hz, 21H), 1.29–1.24(m, 2H), 0.97(d, J=8.1Hz, 6H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 63 H 84 N4O 19 [M+H] + : 1201.57; found:1201.12. Synthesis Route 4

[0061] Example 15: Synthesis of Compound 14 In a 500 mL round-bottom flask, L-glutamic acid di-tert-butyl hydrochloride (15.0 g, 51.0 mmol) was dissolved in ultra-dry dichloromethane. Pyridine (20.5 g, 25.5 mmol) was added under nitrogen protection. The reaction flask was placed on an ice-water bath, and 7.5 mL of trichloromethyl chloroformate (12.0 g, 60.9 mmol) was slowly added dropwise. After the addition was complete, the ice-water bath was removed, and the reaction mixture was stirred under nitrogen protection at room temperature for 5 h. After the reaction was complete, the reaction solution was washed twice with 1 N HCl, then twice with saturated brine. The solution was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain 13.9 g of compound 14. Yield: 95%.

[0062] NMR analysis: 1 H NMR (300MHz, CDCl3): δ4.11 (m, 1H), 2.35(t, J=7.2Hz, 2H), 2.31(m, 2H), 1.42(s, 18H); Mass spectrometry analysis: MS (ESI, m / z): calcd for C 15 H 23 NO5[M+H] + :286.16; found: 286.21. Example 16: Synthesis of Compound 15 Compound 14 (9.0 g, 15.8 mmol) and H-Lys(Z)-OtBu.HCl (9.78 g, 26.4 mmol) were dissolved in 200 mL of anhydrous dichloromethane, and triethylamine (11.0 mL, 79.2 mmol) was added dropwise. The mixture was stirred at room temperature for 3 h. After the reaction was complete, the mixture was partitioned in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The solution was purified by silica gel column chromatography (eluent: methanol:dichloromethane / 1-5%) to give 15.7 g of compound 15. Yield: 95%.

[0063] NMR analysis: 1 H NMR (300MHz, CDCl3): δ7.40–7.29(m, 5H), 5.17(d, J =8.0Hz,2H), 4.33(td, J =8.1, 3.8Hz, 2H), 3.18(d, J =7.4Hz, 2H), 2.36–2.23(m, 2H), 2.06(q, J =5.7Hz, 2H), 1.88–1.75(m, 2H), 1.52(s, 2H), 1.44(d, J =7.2Hz, 27H), 1.30–1.20(m, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 32 H 51 N3O9[M+H] + : 622.36; found: 622.14. Example 17: Synthesis of Compound 16 Compound 15 (10.0 g, 16.08 mmol) was dissolved in 20 mL of methanol, and 800 mg of palladium on carbon was added for hydrogenation. The mixture was stirred for 2 h. The reaction mixture was evaporated to dryness, redissolved in ethyl acetate, filtered through diatomaceous earth, and the filtrate was evaporated to dryness. The filtrate was purified by silica gel column chromatography (eluent: methanol:dichloromethane / 2 - 15%) to give 6.67 g of pure compound 16. Yield: 85%.

[0064] NMR analysis: 1 H NMR (300MHz, DMSO-d6): δ6.32(dd, J =16.5, 8.3Hz, 2H), 3.99(m2H), 3.17(s, 2H), 2.29–2.15(m, 2H), 1.91–1.81(m, 1H), 1.67(m, 1H), 1.55(m,2H), 1.41–1.35(m, 29H), 1.34–1.29(m, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 24 H 45 N3O7[M+H] + : 488.33; found:488.39. Example 18: Synthesis of Compound 17 Compound 4-O-(Z-amino)-n-propoxyphenylacetic acid (6.0 g, 16.8 mmol) and HATU (6.6 g, 17.4 mmol) were dissolved in 60 mL of anhydrous DMF, followed by the addition of triethylamine (3.0 mL, 22.38 mmol), and the reaction was allowed to proceed for 1 h. Compound 16 (4.8 g, 11.2 mmol) was dissolved in anhydrous DMF and added dropwise to the reaction mixture, and the reaction was allowed to proceed for 3 h. After the reaction was complete, the mixture was partitioned in ethyl acetate and saturated brine. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The purified compound 17 was then purified by column chromatography (eluent: methanol:dichloromethane / 0-4%) to give 6.17 g of compound 17. Yield: 71%.

[0065] NMR analysis: 1 H NMR (300MHz, DMSO-d6): δ7.78(d, J =5.8Hz, 1H), 7.34(d, J =6.6Hz, 5H), 7.08(dd, J =8.6, 2.1Hz, 2H), 6.80(dd, J =8.5, 2.1Hz, 2H), 6.28(m,2H), 5.01(d,J =2.0Hz, 2H), 4.09–3.90(m, 4H), 3.16(t, J =6.7Hz, 2H), 3.01(t, J =6.7Hz, 2H), 2.79–2.62(m, 4H), 2.37–2.14(m, 5H), 1.89–1.82(m, 3H), 1.74–1.50(m, 4H), 1.39(d, J =2.3Hz, 27H), 1.25(d, J =8.5Hz, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 44 H 66 N4O 11 [M+H] + : 827.47; found:827.42. Example 19: Synthesis of Compound 18 The synthesis method of compound 18 is similar to that of compound 16.

[0066] NMR analysis: 1 H NMR (300MHz, DMSO-d6): δ7.77(t, J=5.7Hz, 1H), 7.09(d, J=8.5Hz, 2H), 6.82(d, J=8.5Hz, 2H), 6.28(dd, J=13.7, 8.3Hz, 2H), 4.06–3.92(m,4H), 3.00(d, J=6.9Hz, 2H), 2.86(t, J=7.2Hz, 2H), 2.72(t, J=7.8Hz, 2H), 2.33–2.17(m, 6H), 1.90(q, J=6.1Hz, 2H), 1.71–1.54(m, 2H), 1.39(d, J=3.0Hz, 31H), 1.24(s, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 36 H 60 N4O9[M+H] + : 693.43; found: 693.53. Example 20: Synthesis of Compound 19 Propargyl-PEG7-acid (2.75 g, 6.25 mmol), EDCI (1.44 g, 7.5 mmol), and NHS (863 mg, 7.5 mmol) were dissolved in 30 mL of anhydrous dichloromethane and stirred at room temperature for 3 h. After the reaction was complete, the organic layer was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness to obtain a pale yellow oil (3.35 g, 6.2 mmol), which was the Propargyl-PEG7-NHS ester. Compound 18 (2.0 g, 2.8 mmol) was dissolved in 30 mL of anhydrous DMF, and triethylamine (1.6 mL, 11.2 mmol) was added. The mixture was stirred at room temperature for 45 min, and then the Propargyl-PEG8-NHS ester (1.25 g, 2.3 mmol) prepared above was added. The mixture was stirred at room temperature for another 3 h. After the reaction was complete, the pH of the reaction system was adjusted to 3.0-4.0 with 1 N HCl solution. The mixture was partitioned in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The purified phase was then purified on a silica gel column (eluent: methanol:dichloromethane / 1-6%) to give 2.16 g of compound 19. Yield: 83%.

[0067] NMR analysis: 1 H NMR(600MHz, DMSO-d6): δ7.90(t, J=5.7Hz, 1H), 7.76(t, J=5.6Hz, 1H), 7.08(d, J=8.5Hz, 2H), 6.83–6.78(m, 2H), 6.28(dd, J=14.3, 8.3Hz,2H), 4.14(d, J=2.4Hz, 2H), 4.04(m, 1H), 3.93(dt, J=12.7, 5.9Hz, 3H), 3.59(t,J=6.5Hz, 2H), 3.55–3.45(m, 28H), 3.42(t, J=2.4Hz, 1H), 3.18(q, J=6.5Hz, 2H),3.00(q, J=6.4Hz, 2H), 2.75–2.69(m, 2H), 2.34–2.16(m, 6H), 1.84(m, 3H), 1.70–1.53(m, 2H), 1.39(d, J=3.0Hz, 27H), 1.24(s, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 56 H 94 N4O 18 [M+Na] +: 1133.65; found:1133.78. Example 21: Synthesis of Compound 20 Compound 19 (2.0 g, 1.80 mmol) was dissolved in 10 mL of dichloromethane, and 10 mL of trifluoroacetic acid was added dropwise. The reaction was stirred for 5 h. After the reaction was complete, the solution was evaporated to dryness and purified by reverse-phase C-18 column chromatography (mobile phase: acetonitrile:water / 20-65%) to give 1.46 g of compound 20. Yield: 75%.

[0068] NMR analysis: 1 HNMR(600MHz, DMSO-d6): δ7.33–7.28(m, 1H), 7.11(d, J =8.5Hz,2H), 6.90–6.74(m, 2H), 4.14(d, J =2.4Hz, 2H), 3.99(m, 28H), 3.29(t, J =2.4Hz,1H), 3.24–3.19(m, 2H), 3.01(t, J =6.9Hz, 2H), 2.74(t, J =7.5Hz, 2H), 2.31(dt, J =22.1, 6.3Hz, 6H), 2.01–1.70(m, 5H), 1.68–1.48(m, 2H), 1.35(q, J =6.5Hz, 2H), 1.25(m, J =6.3Hz, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 44 H 70 N4O 18 [M+H] + : 943.46; found: 943.58. Synthesis Route 5

[0069] Example 22: Synthesis of Compound 21 To a 500 mL round-bottom flask, 50.0 g (60.80 mmol) of docetaxel, 32.6 g (216.3 mmol) of imidazole, and 150 mL of dimethylformamide solvent were added sequentially, followed by 14.3 g (216.3 mmol) of tert-butyldimethylchlorosilane. The mixture was stirred overnight at room temperature. After the reaction was complete, the reaction mixture was partitioned in saturated sodium chloride solution (500 mL) and ethyl acetate (500 mL), separating the ethyl acetate layer. The ethyl acetate layer was further washed twice with saturated sodium chloride solution (500 mL × 2) and dried over anhydrous MgSO4, filtered, evaporated to dryness, and subjected to silica gel column chromatography (eluent: ethyl acetate: petroleum ether / 10–70%) to give 53.6 g of compound 21. Yield: 95%.

[0070] NMR analysis: 1 H NMR (400 MHz, CDCl3): δ 8.12 (d, J = 7.2 Hz, 2H), 7.59 (t, J =7.6 Hz, 1H), 7.49 (t, J = 8.0 Hz, 2H), 7.37 (t, J = 7.6 Hz, 2H), 7.32 - 7.24 (m,3H), 6.34 (t, J = 9.6 Hz, 1H), 5.70 (d, J = 7.2 Hz, 1H), 5.43 (d, J = 9.6 Hz, 1H), 5.31 (d, J = 8.0 Hz, 1H), 4.98 (d, J = 8.4 Hz, 1H), 4.52 (s, 1H), 4.35 - 4.2 (m,3H), 4.12 (q, J = 7.2 Hz, 1H), 3.96 (d, J = 7.2 Hz, 1H), 2.70 - 2.49 (m, 4H), 2.37 (dd, J = 16.8, 9.6 Hz, 1H), 2.15 (dd, J = 13.6, 4.8 Hz, 1H), 1.96 - 1.81 (m,4H), 1.79 - 1.59 (m, 5H), 1.34 - 1.20 (m, 13H), 1.12 (s, 1H), 0.74 (s, 9H), -0.10 (s, 3H), -0.30 (s, 3H). Mass spectrometry analysis: ESI-MS ( m / z ): calcd for C 49 H 68 NO 14 Si [M+H] + : 922.44; found: 922.03. Example 23: Synthesis of Compound 22 In a 500 mL round-bottom flask, add 45.0 g (48.8 mmol) of compound 21 and 13.2 g (107.3 mmol) of DMAP, then add 200 mL of anhydrous THF and cool to 0°C under nitrogen protection. o C, then add 30.0 mL (282.0 mmol) of AllocCl. After stirring for another 10 minutes, remove the cooled mixture, allow the reaction mixture to warm to room temperature, and continue stirring for 12 hours. After the reaction is complete, evaporate the reaction mixture to dryness, partition it in dichloromethane (300 mL) and a saturated sodium citrate solution (300 mL), wash the organic phase twice with a saturated sodium citrate solution (300 mL × 2), dry it with anhydrous sodium sulfate, filter, concentrate, and elute and purify it on a silica gel column with ethyl acetate / petroleum ether (10–50%) to give 45.5 g of compound 22. Yield: 84%.

[0071] NMR analysis: 1 H NMR (400 MHz, CDCl3): δ 8.12 (d, J = 7.2 Hz, 2H), 7.59 (t, J =7.6 Hz, 1H), 7.49 (t, J = 8.0 Hz, 2H), 7.37 (t, J = 7.6 Hz, 2H), 7.32 - 7.24 (m,3H), 6.35 - 6.20 (m, 2H), 6.05 - 5.90 (m,2H), 5.71 (d, J = 8.4 Hz, 1H), 5.52(dd, J = 10.8, 7.2 Hz, 1H), 5.45 - 5.20 (m, 6H), 4.98 (d, J = 7.6 Hz, 1H), 4.65(m, 4H), 4.47 (d, J = 2.5 Hz, 1H), 4.20 (d, J = 8.0 Hz, 1H), 4.12 (q, J= 7.2 Hz, 1H), 3.97 (d, J = 7.6 Hz, 1H), 2.68 - 2.53 (m,4H), 2.39 (dd, J = 15.2, 9.6 Hz, 1H), 2.21 (dd, J = 16.0, 8.8 Hz, 1H), 2.08 - 1.95 (m, 5H), 1.84 (s, 2H), 1.64(s, 2H), 1.37 - 1.23(m, 13H) 1.19 (s, 3H), 0.74 (s, 9H), 0.07 (s, 3H), -0.31(s, 3H). Mass spectrometry analysis: ESI-MS ( m / z ): calcd for C 57 H 75 NO 18 Si [M+Na] + : 1112.46; found: 1112.50. Example 24: Synthesis of Compound 23 To a 500 mL round-bottom flask, 25.0 g (22.95 mmol), compound 22, and 50.0 mL (1.0 M) tetrabutylammonium fluoride in tetrahydrofuran were added sequentially. The mixture was stirred at room temperature for 5 hours. After the reaction was complete, the solution was evaporated to dryness and purified by silica gel column chromatography (eluent: petroleum ether: ethyl acetate / 10–70%) to give 21.6 g of compound 23. Yield: 96%.

[0072] NMR analysis: 1 H NMR (400 MHz, CDCl3): δ 8.1 (d, J = 8.0 Hz, 2H), 7.61 (t, J =6.8 Hz, 1H), 7.49 (t, J = 7.6 Hz, 2H), 7.43 - 7.28 (m,5H), 6.25 - 6.14 (m, 2H), 6.04 - 5.91 (m,2H), 5.53 - 5.35(m,3H), 5.34 - 5.22 (m, 3H), 4.72 - 4.60 (m,4H), 4.32 (d, J = 8.4 Hz, 1H), 4.22 - 4.07 (m, 3H), 3.92 (d, J= 6.8 Hz, 1H),2.62 (m,1H), 2.45 - 2.25 (m, 4H), 2.10 - 2.02(m,3H) 1.99 - 1.92 (m, 3H), 1.83(s, 3H), 1.36 (s, 9H), 1.30 - 1.23 (m, 6H), 1.20(s, 3H). Mass spectrometry analysis: ESI-MS ( m / z ): calcd for C 51 H 61 NO 18 [M+Na] + : 998.37; found:998.37. Example 25: Synthesis of Compound 24 In a 250 mL round-bottom flask, compound 9 (5.00 g, 9.23 mmol), DMAP (1.13 g, 9.23 mmol), and EDCI (1.77 g, 9.23 mmol) were dissolved in 100.0 mL of anhydrous THF. Compound 23 (4.6 g, 4.62 mmol) was then added, and the mixture was stirred overnight at room temperature. The reaction mixture was concentrated and purified by elution on a silica gel column with methanol / dichloromethane (1.0–5.0%) to give 3.65 g of compound 24. Yield: 53%.

[0073] NMR analysis: 1 H NMR (600MHz, DMSO-d6): δ8.35(m, 1H), 7.95(dd, J =8.8, 7.1Hz, 2H), 7.86(t, J =5.7Hz, 1H), 7.73(m, 1H), 7.65 (m, 2H), 7.47–7.29(m, 4H), 7.23(t, J =7.3Hz, 1H), 6.01 (m, 2H), 5.81(t, J =9.1Hz, 1H), 5.45–5.29(m, 10H), 5.13(d, J =7.7Hz, 2H), 4.98–4.70(m, 5H), 4.65(s, 1H), 4.49(s, 1H), 4.25 (m, 1H), 4.04–3.96(m, 3H), 3.73 (dd, J =10.5, 6.7Hz, 1H), 3.55(d, J =7.1Hz, 1H), 3.01(q,J =6.4Hz, 2H), 2.87(s, 1H), 2.76 (t, J =5.8Hz, 3H), 2.75–2.72(m, 2H), 2.37–2.29(m,2H), 2.28–2.19(m, 5H), 2.18–2.08(m, 2H), 2.03(m, 4H), 1.73(s, 3H), 1.65(m,2H), 1.47(d, J =7.9Hz, 6H), 1.37(s, 9H), 1.33–1.22(m, 13H), 0.97 (d, J =7.6Hz, 6H), 0.86(t, J =6.8Hz, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 82 H 109 N4O 22 [M+H] + : 1501.75; found: 1501.87. Example 26: Synthesis of Compound 25 Compound 24 (7.2 g, 4.80 mmol), N,N-dimethylbarbituric acid (1.52 g, 9.6 mmol), and tetrakis(triphenylphosphine)palladium (560 mg, 0.48 mmol) were dissolved in 50.0 mL of anhydrous THF and stirred at room temperature for 3 hours. After the reaction was complete, the reaction mixture was concentrated and purified by elution with methanol / dichloromethane (1.0–6.0%) on a silica gel column to give 4.75 g of compound 9. Yield: 73%.

[0074] NMR analysis: 1 H NMR (600MHz, DMSO-d6): δ8.42–8.31(m, 1H), 7.96(dd, J =8.8,7.1Hz, 2H), 7.82(t, J =5.7Hz, 1H), 7.75(m, 1H), 7.63(m, 2H), 7.47–7.29(m, 4H),7.21(t, J =7.3Hz, 1H), 5.81(t, J =9.1Hz, 1H), 5.38–5.29(m, 6H), 5.13(d, J=7.7Hz,2H), 4.98–4.90(m, 1H), 4.65(s, 1H), 4.49(s, 1H), 4.26(m, 1H), 4.04–3.96(m,3H), 3.73 (dd, J =10.5, 6.7Hz, 1H), 3.55(d, J =7.1Hz, 1H), 3.01(q, J =6.4Hz, 2H),2.89(s, 1H), 2.79(t, J =5.8Hz, 3H), 2.75–2.72(m, 2H), 2.37–2.29(m, 2H), 2.28–2.19(m, 5H), 2.18–2.08(m, 2H), 2.03(m, 4H), 1.75(s, 3H), 1.63(m, 2H), 1.49(d, J =7.9Hz, 6H), 1.39(s, 9H), 1.33–1.22(m, 13H), 0.98(d, J =7.6Hz, 6H), 0.85(t, J =6.8Hz, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 74 H 101 N4O 18 [M+H] + : 1333.70; found: 1333.96. Synthesis Route 5

[0075] Example 27: Synthesis of Compound 26 Compound 18 (10.0 g, 14.44 mmol) was dissolved in 30 mL of dichloromethane, and 30 mL of trifluoroacetic acid was added dropwise. The reaction mixture was stirred overnight. After the reaction was complete, the solution was evaporated to dryness and purified by reverse-phase C-18 column chromatography (mobile phase: acetonitrile:water / 5-50%) to give 4.97 g of compound 26. Yield: 62%.

[0076] NMR analysis: 1H NMR (300MHz, DMSO-d6): δ7.78(m,3H), 7.09(d, J=6.8Hz, 2H), 6.82(d, J=6.8Hz, 2H), 6.31(m, 2H), 4.06–3.95 (m, 4H), 2.93(m, 2H), 2.76(t, J=7.2Hz, 2H), 2.52(m, 4H), 2.05 (m, 3H), 1.75–1.48(m, 3H), 1.73(m, 2H), 1.25(m, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 24 H 37 N4O9[M+H] + : 525.25; found:525.31. Example 28: Synthesis of Compound 27 Compound 26 (2.0 g, 3.81 mmol) was dissolved in 20 mL of anhydrous DMF, followed by the addition of triethylamine (3.5 mL) and BCN-PEG3-acid NHS ester (1.9 g, 3.81 mmol). The reaction mixture was stirred overnight. After the reaction was complete, the solution was evaporated to dryness and purified by reverse-phase C-18 column chromatography (mobile phase: acetonitrile:water / 5-70%) to give 1.17 g of compound 27. Yield: 37%.

[0077] NMR analysis: 1 H NMR (300MHz, DMSO-d6): δ 8.00-7.50 (m,4H), 7.10(d, J=6.8Hz, 2H), 6.83(d, J=6.8Hz, 2H), 6.35(m, 2H), 4.25 (t, J=7.2Hz, 2H), 4.05–3.93 (m, 6H), 3.70 - 3.30 (m, 10H), 3.25 - 3.00 (m, 6H), 2.98 (t, J=72Hz, 2H), 2.76 (t, J=7.0Hz, 2H), 2.30 - 2.00 (m, 10H),1.75(m, 3H), 1.55-1.49(m,3H), 1.35-1.20 (m, 7H), 0.98 (m, 2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 44 H 65 N5O 15 [M+H] +: 904.45; found: 904.67. Synthesis Route 6

[0078] Example 29: Synthesis of Compound 28 In a 250 mL round-bottom flask, compound Lys(GLA)-Gly (4.65 g, 10.0 mmol) was dissolved in 30 mL of anhydrous DMF, followed by the addition of 2.8 mL of triethylamine (20.0 mmol) and (p-phenyl)-BCN-cabonate (3.2 g, 10.0 mmol). The mixture was stirred overnight at room temperature. After the reaction was complete, the mixture was evaporated to dryness. The reaction mixture was partitioned in ethyl acetate and 10% citric acid (100 mL). The organic phase was washed twice with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated, and purified on a silica gel column using a methanol / dichloroisocyanuric acid (1–10%) gradient elution to give 2.37 g of compound 28. Yield: 37%.

[0079] NMR analysis: 1 H NMR (600MHz, DMSO-d6): δ 7.65 (m, 2H), 5.35 (m, 6H), 4.25-4.10 (m,5H), 3.05 (t, J=7.2Hz, 2H), 2.75 (m, 6H), 2.50 - 2.10(t, J=7.2Hz,8H), 2.05 (m, 4H), 1.70-1.5 (m, 8H), 1.25-0.95 (m, 13H), 0.84 (t, J=7.2Hz,2H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 37 H 58 N3O8[M+H] + : 640.45; found: 640.71. Example 30: Synthesis of Compound 29 Compound 28 (2.0 g, 3.13 mmol), DMAP (382 mg, 3.13 mmol), and EDCI (900 mg, 4.70 mmol) were dissolved in 20 mL of anhydrous DMF and stirred for 30 min. Then, cabazitaxel (CTX 2.6 g, 3.13 mmol) was dissolved in 10 mL of anhydrous DMF and added dropwise to the reaction mixture. The reaction was allowed to proceed overnight at room temperature. After the reaction was complete, the reaction system was partitioned in saturated brine and ethyl acetate. The organic phase was washed three times with saturated brine, dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The purified compound was then purified by silica gel column chromatography (eluent: ethyl acetate: petroleum ether / 20 - 100%) to give 2.33 g of compound 29. Yield: 51%.

[0080] NMR analysis: 1 H NMR (600MHz, DMSO-d6): δ8.42–8.30 (m, 1H), 7.96(dd, J =8.8, 7.1 Hz, 2H), 7.83 (t, J =5.7Hz, 1H), 7.72(m, 1H), 7.63(m, 2H), 7.47–7.29(m, 4H),7.15(t, J =7.3Hz, 1H), 5.84(t, J =9.1Hz, 1H), 5.38–5.29(m, 6H), 5.10(d, J =7.7Hz,2H), 4.98–4.90(m, 1H), 4.67 (s, 1H), 4.52(s, 1H), 4.27(m, 1H), 4.04–3.96(m,5H), 3.74(dd, J =10.5, 6.7Hz, 1H), 3.58(d, J =7.1Hz, 1H), 3.28(s, 3H), 3.20(s,3H), 3.01(q, J =6.4Hz, 2H), 2.89(s, 1H), 2.77(t, J =5.8Hz, 3H), 2.75–2.72(m, 2H), 2.28–2.19(m, 5H), 2.18–2.08(m, 8H), 1.78(s, 3H), 1.56 (m, 4H), 1.49(d, J =7.9Hz, 6H), 1.39(s, 9H), 1.33–1.00 (m, 10H), 0.98(m, 7H), 0.87(t, J=6.8Hz, 3H). Mass spectrometry analysis: MS (ESI, m / z): calcd for C 82 H 113 N4O 19 [M+H] + : 1457.79; found:1457.93. Synthesis Route 6

[0081] Example 31: Coupling 30a (Dex-CTX-GLA-L) PSMA Synthesis of ) Bifunctionalized dextran 4a (6.0 g), compound 10 (780 mg), and compound 20 (300 mg) were dissolved in 20.0 mL of DMSO-water (9:1). 1.0 N CuSO4 (990 μL, 0.99 mmol) and 1.0 M sodium ascorbate (2.0 mL, 2.0 mmol) were added, and the mixture was stirred overnight at room temperature. After the reaction was complete, the reaction mixture was diluted to distilled water (60 mL) and filtered. The filtrate was washed with dichloromethane (60 mL), dialyzed three times using a dialysis bag with a molecular weight cutoff of 30,000 Daltons, concentrated, and lyophilized to give conjugate 30a (5.57 g). Yield: 93%.

[0082] NMR analysis: 1 H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.10 - 6.70 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). Example 32: Coupling 30b (Dex-CTX-GLA-L) PSMA Synthesis of ) The preparation method of coupling 30b is similar to that of coupling 30a.

[0083] NMR analysis: 1H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.10 - 6.70 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). Synthesis Route 6

[0084] Example 33: Coupling 31 (Dex-CTX-L) PSMA Synthesis of ) The preparation method of coupling 31 is similar to that of coupling 30b.

[0085] NMR analysis: 1 H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.10 - 6.70 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). Synthesis Route 7

[0086] Example 34: Coupling 32 (Dex-DTX-GLA-L) PSMA Synthesis of ) The preparation method of coupling 32 is similar to that of coupling 30b.

[0087] NMR analysis: 1 H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.10 - 6.70 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). Synthesis Route 8

[0088] Example 35: Synthesis of Coupling 33 Bifunctionalized dextran 4a (2.0 g), compound 27 (250 mg), and compound 29 (120 mg) were dissolved in 10.0 mL of DMSO and stirred overnight at room temperature. After the reaction was complete, the reaction mixture was diluted to 50 mL of distilled water and filtered. The filtrate was washed with dichloromethane (50 mL), dialyzed three times using a dialysis bag with a molecular weight cutoff of 30,000 Daltons, concentrated, and lyophilized to give conjugate 30a (1.92 g). Yield: 96%.

[0089] NMR analysis: 1 H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.10 - 6.70 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). Synthesis Route 9

[0090] Example 36: Synthesis of Coupling 34 (Dex-CTX-GLA) Bifunctionalized dextran 4a (1.0 g) and compound 10 (120 mg) were dissolved in 6.0 mL of DMSO-water (9:1), and 1.0 N CuSO4 (250 μL, 0.25 mmol) and 1.0 M sodium ascorbate (400 μL, 0.4 mmol) were added and stirred overnight at room temperature. After the reaction was complete, the reaction mixture was diluted to distilled water (30 mL) and filtered. The filtrate was washed with dichloromethane (30 mL), dialyzed three times using a dialysis bag with a molecular weight cutoff of 30,000 Daltons, concentrated, and lyophilized to give conjugate 34 (1.79 g). Yield: 89%.

[0091] NMR analysis: 1H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.10 - 7.00 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). Synthesis Route 10

[0092] Example 37: Synthesis of Coupling 35 (Dex-CTX) The preparation method of coupling 35 is similar to that of coupling 30b.

[0093] NMR analysis: 1 H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.10 - 6.70 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). Synthesis Route 11

[0094] Example 38: Synthesis of Coupling 36 (Dex-cy7.5) The preparation method of coupling 36 is similar to that of coupling 30b.

[0095] NMR analysis: 1 H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.50 - 7.2 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). Synthesis Route 12

[0096] Example 39: Coupling 37 (Dex-Cy7.5-L) PSMA Synthesis of ) The preparation method of coupling 37 is similar to that of coupling 30b.

[0097] NMR analysis: 1 H NMR (selected characteristic signals, 500MHz, DMSO-d6+D2O): major signals: δ 4.50 - 5.00 (m, CHO), 3.50 - 4.00 (m, CHOH, CH2OH); minor signals: δ 8.50 - 6.50 (m, ArH), 5.25 (m, =CH), 0.95 - 1.10 (m, CH3). In vitro inhibition of PSMA tumor proliferation assay Two cell lines with high PSMA expression (22rv1 and LNCaP) and one cell line with low PSMA expression (PC3) were selected and cultured in culture medium until they were in good growth condition. The cells were then digested with trypsin, centrifuged, collected, resuspended in serum-containing medium, and diluted to 1×10⁻⁶. 5 Single-cell suspension of 100 µL cells / mL was added to each well of a 96-well plate and incubated at 37°C in a 5% CO2 incubator for 24 h. After 48 hours, the culture medium was aspirated, and drug-containing medium was added to the experimental group, while drug-free medium was added to the control group. The plates were incubated for 72 h. After the incubation period, the culture medium was discarded, and 100 µL of CCK-8 (basal culture medium: CCK-8 reagent = 9:1) was added to each well. After completing the above steps, the plates were incubated at 37°C for 1.5 h, and the absorbance was measured using a microplate reader.

[0098] Table 1. IC50 of the coupling agent on each cell at 72 h. 50 value

[0099] Conclusion: The conjugate with the PSMA-targeting ligand exhibited stronger inhibitory activity against the PSMA-overexpressing cell line than against the low-PSMA-expressing cell line, and also stronger inhibitory activity against the PSMA-overexpressing cell line without the PSMA-targeting ligand. In the PSMA-low-expressing cell line, the IC50 of the conjugate was significantly higher. 50 The values ​​were no different from those of the original drug CTX. Experimental results indicate that the PSMA-targeting ligand conjugate has enhanced cytotoxicity in PSMA-high expressing tumor cells.

[0100] Animal tumor targeted trials Fluorescent dyes and their conjugates were injected intravenously into nude mice with 22Rv1 prostate cancer cell xenografts, and the fluorescence intensity of the tumors was measured at different time points. Results are as follows: Figure 1 As shown. The results showed that: (1) the fluorescence intensity in the tumor of the Cy7.5 group was very low, significantly lower than that of the two conjugate groups, and gradually decreased after 4 h. (2) the fluorescence intensity in the tumor of the two conjugate groups first increased with time, and began to decrease after 8 h, Dextran-Cy7.5-L PSMA The fluorescence intensity of the conjugate was significantly higher than that of the Dextran-Cy7.5 conjugate group from 1 to 96 h. (3) At 96 h, the fluorescence intensity of the Dextran-Cy7.5-L PSMA The fluorescence intensity of the conjugate in tumors was higher than that in normal tissues (heart, liver, spleen, lung). (4) At 96 h, Dextran-Cy7.5-L PSMA The fluorescence intensity of the conjugate in the tumor was higher than that of the Cy7.5 and Dextran-Cy7.5 conjugate groups.

[0101] Conclusion: The above results indicate that the coupling Dextran-Cy7.5-L PSMA Couplers have tumor targeting and tissue selectivity, and can remain in tumors for a long time.

[0102] In vivo antitumor activity and safety evaluation of conjugates In vivo antitumor experiments were conducted using two batches of 22Rv1 and PC-3 / PSMA tumor-bearing nude mouse models. The antitumor activity of the conjugate was evaluated by monitoring changes in tumor volume and body weight in the nude mice during drug administration.

[0103] Results of in vivo tumor suppression assay and survival curve analysis in 22Rv1 tumor-bearing nude mice Evaluation of the prototype drug cabazitaxel (CTX), conjugate 35 (Dextran-CTX), and conjugate 31 (Dextran-CTX-L) using a 22Rv1 tumor-bearing nude mouse model. PSMA ) and coupling 30b (Dextran-CTX-GLA-L PSMA The antitumor activity of ) was observed. Results were as follows: Figure 2 and Figure 3 The results showed that: (1) there was a dose-dependent relationship between the tumor inhibition rates of the two dose groups of each drug. (2) at a dose of 5 mg / kg, the tumor inhibition rates of all three conjugate groups were higher than those of the original drug CTX.

[0104] (3) At doses of 5 mg / kg and 10 mg / kg, the tumor inhibition rates of conjugate 31 (Dextran-CTX) were 75.2% and 80.5%, respectively, and those of conjugate 35 (Dextran-CTX-L) were 80.5%. PSMA The tumor inhibition rates of the two drugs were 80.2% and 90.7%, respectively, and the conjugate 31 (Dextran-CTX-L) showed similar results. PSMA The activity of conjugate 30b (Dextran-CTX-GLA-L) was stronger than that of conjugate 35 (Dextran-CTX). (4) At doses of 5 mg / kg and 10 mg / kg, conjugate 30b (Dextran-CTX-GLA-L) was more active than that of conjugate 35 (Dextran-CTX-GLA-L). PSMA Due to the synergistic antitumor effect of the contained GLA, the tumor inhibition rates increased to 93.5% and 95.2%, respectively. These results indicate that conjugate 30b (Dextran-CTX-GLA-L) exhibits significant antitumor activity. PSMA The conjugate has the strongest antitumor activity.

[0105] Figure 3 The study showed changes in body weight in nude mice during administration. Both dosage groups of the parent drug cabazitaxel (CTX) experienced a sustained decrease in body weight. Specifically, the 10 mg / kg CTX group showed a 20% decrease in body weight on day 14, while the 5 mg / kg group showed a 10% decrease on day 28. This indicates that both doses of the parent drug cabazitaxel (CTX) exhibit strong general toxicity in nude mice. In contrast, the control and conjugate groups showed stable body weight with a slight upward trend, suggesting that the conjugate significantly improved safety.

[0106] Conclusion: The above results indicate that in nude mice with PSMA-overexpressing prostate cancer cell 22Rv1 xenografts, conjugates 31 and 30b exhibit high antitumor activity and safety, and significantly reduce the toxicity of the antitumor drug cabazitaxel, suggesting that the tolerable dose of the drug can be significantly improved to achieve optimal anticancer efficacy.

[0107] Results of in vivo tumor suppression assay in nude mice with PC-3 / PSMA tumor-bearing cells Evaluation of the prototype drug cabazitaxel (CTX), conjugate 35 (Dextran-CTX), and conjugate 31 (Dextran-CTX-L) using a PC-3 / PSMA tumor-bearing nude mouse model PSMA ) and coupling 30b (Dextran-CTX-GLA-L PSMA The result is as follows: Figure 4 and Figure 5As shown: (1) There was a dose-dependent relationship between the tumor inhibition rates of the two dose groups for each drug. (2) At a dose of 5 mg / kg, the tumor inhibition rates of all three conjugate groups were higher than those of the parent drug cabazitaxel (CTX). (3) At doses of 5 mg / kg and 10 mg / kg, the tumor inhibition rates of conjugate 35 (Dextran-CTX) were 34.7% and 47.6%, respectively, and those of conjugate 31 (Dextran-CTX-L) were higher. PSMA The tumor inhibition rates of conjugate 30b (Dextran-CTX-GLA-L) were 66.5% and 86.9%, respectively, and the activity of conjugate 31 was stronger than that of conjugate 35. (4) At doses of 5 mg / kg and 10 mg / kg, the tumor inhibition rates of conjugate 30b (Dextran-CTX-GLA-L) were 66.5% and 86.9%, respectively, and the activity of conjugate 31 was stronger than that of conjugate 35. PSMA Due to the synergistic antitumor effect of the contained GLA, the tumor inhibition rates increased to 89.1% and 96.6%, respectively. These results indicate that conjugate 30b (Dextran-CTX-GLA-L) exhibits significant antitumor activity. PSMA PC-3 / PSMA exhibits the strongest antitumor activity. In vivo safety evaluation in nude mice bearing tumors. During the administration period, the body weight of nude mice in both dose groups of cabazitaxel (CTX) showed a continuous decreasing trend; after 14 days of administration, the average body weight of nude mice in the 5 mg / kg and 10 mg / kg dose groups decreased by 10% and 20%, respectively; at the end of the 21-day experiment, there was no significant difference in body weight between the control group and the conjugate group, and there was a slight increasing trend. Figure 6 The nude mice were healthy and in good spirits.

[0108] Conclusion: The above results indicate that in nude mice with PSMA-expressing prostate cancer cell line PC-3 / PSMA xenografts, conjugates 31 and 30b exhibit high antitumor activity and safety, significantly reduce the toxicity of the antitumor drug cabazitaxel, and increase the tolerable dose of the drug.

[0109] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A polysaccharide drug conjugate targeting PSMA, characterized in that, Its structure is shown in general formula I, or is an isomer or derivative thereof, or a pharmaceutically acceptable salt or solvate thereof; General Formula I Among them, spacer 4, linker arm 3, or target PSMA ligand are covalently linked to the polysaccharide binding site of the polysaccharide, and spacer 4, linker arm 3 and target PSMA ligand are covalently linked. Spacer 1, linker arm 1, branched structural unit, spacer 2, linker arm 2, or taxane compound are covalently linked to the polysaccharide binding site of the polysaccharide. Spacer 1, linker arm 1, branched structural unit, spacer 2, linker arm 2 are covalently linked to the taxane compound, and branched structural unit, spacer 3, and unsaturated fatty acid unit are covalently linked. The covalent bonds are selected from amide bonds, carbamate bonds, aminothiocarbamate bonds, ester bonds, isourea bonds, thiourea bonds, urea bonds, disulfide bonds, carbonate bonds, phosphate ester bonds, phosphoamide bonds, sulfonamide bonds, α-glycosidic bonds, β-glycosidic bonds, and triazole-containing covalent bonds.

2. The polysaccharide drug conjugate targeting PSMA as described in claim 1, characterized in that, The polysaccharide binding sites are selected from the hydroxyl, carboxyl, amino, phosphate, and sulfonic acid groups of the polysaccharide; Alternatively, the polysaccharide is selected from dextran, levtran, hyaluronic acid, cyclodextrin, hydroxyethyl starch, xylan, polysialic acid, Ganoderma lucidum polysaccharide, lentinan, and amylose, and the molecular weight of the polysaccharide is in the range of 0.3k to 3000k Daltons; preferably, it is dextran. Alternatively, the polysaccharide may be a modified polysaccharide or an unmodified polysaccharide; preferably, the modified polysaccharide contains a glutamic acid fragment, and more preferably, the modifying group is... .

3. The PSMA-targeting polysaccharide drug conjugate as described in claim 1, characterized in that the connecting arm 1. Linker arm 2 and linker arm 3 are each independently selected from the following structures: disubstituted C5-20 alkyl, C5-20 cycloalkyl, C5-20 heterocycloalkyl, C5-20 alkenyl, C5-20 alkynyl, C6-20 aryl or C5-20 heteroaryl, disubstituted peptides containing 3 to 10 natural or non-natural amino acids, polyethylene glycol chains with a molecular weight of 300 to 5000, or combinations thereof; Alternatively, the taxanes are selected from natural or semi-synthetic compounds and their derivatives with taxane diterpenes as the parent nucleus; preferably cabazitaxel or docetaxel; Alternatively, the molar ratio of the taxane compound to the targeted PSMA ligand or unsaturated fatty acid unit is arbitrary, preferably 0.1 to 10; Alternatively, the unsaturated fatty acid unit may be a single molecule of unsaturated fatty acid or a structural unit composed of multiple identical or different single molecules of unsaturated fatty acids; preferably, the single molecule of lipid compound is selected from unsaturated fatty acids DHA, EPA, and GLA. Alternatively, spacer 1, spacer 2, spacer 3 and spacer 4 are each independently selected from the following structures: disubstituted C1-10 alkyl, C3-10 cycloalkyl, C3-10 heterocycloalkyl, C3-10 alkenyl, C3-10 alkynyl, C6-10 aryl or C5-10 heteroaryl, natural or non-natural amino acids, disubstituted peptides containing 2 to 3 natural or non-natural amino acids, polyethylene glycol chains with a molecular weight of 100 to 500, or combinations thereof.

4. The polysaccharide drug conjugate targeting PSMA as described in claim 1, characterized in that, The branched structural unit is a trisubstituted structure with a length of 6 to 100 atoms, selected from linear alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, heteroaryl or their derivatives; Alternatively, the branch structure unit can be selected from the following structures: 。 5. The polysaccharide drug conjugate targeting PSMA as described in claim 1, characterized in that, Selected from the following structures: 。 6. The polysaccharide drug conjugate targeting PSMA as described in claim 1, characterized in that, Selected from the following structures: 。 7. A pharmaceutical composition, characterized in that, It includes an active ingredient and a pharmaceutical carrier, wherein the active ingredient is a polysaccharide drug conjugate targeting PSMA as described in any one of claims 1 to 6.

8. The pharmaceutical composition of claim 7, characterized in that, It contains 0.1 to 60% by weight of taxane compounds.

9. The pharmaceutical composition of claim 7, characterized in that, The pharmaceutical composition is formulated as a lyophilized powder, injection, sustained-release formulation, controlled-release formulation, tablet, capsule, or pill.

10. Use of the above-mentioned PSMA-targeting polysaccharide drug conjugate or pharmaceutical composition in the preparation of a medicament for treating PSMA tumors.

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