Glycan, preparation method therefor and use thereof, and Anti-tumor drug

Abstract

A glycan, a preparation method therefor and a use thereof, and an anti-tumor drug, relating to the technical field of medicines. The glycan having a structure as shown in formula I has good anti-tumor activity and good safety. The results of the test example show that the glycan has a good proliferation inhibition effect on pancreatic cancer cells, has no cytotoxicity to the growth of hepatocytes, and shows better safety characteristics compared with a positive drug gemcitabine; in addition, the pancreatic cancer cells are sensitive to the glycan, thereby overcoming the problem that the pancreatic cancer cells have certain drug resistance to gemcitabine.

Description

Polysaccharide, preparation method and application thereof, and antitumor drug

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on September 5, 2023, with application number CN202311139456.1 and invention name “A polysaccharide, its preparation method and application, and anti-tumor drug”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of medical technology, and specifically to a polysaccharide, a preparation method and application thereof, and an anti-tumor drug. Background Art

[0003] Pancreatic cancer is a common, highly malignant digestive system tumor with a five-year survival rate of less than 10%, making it the second leading cause of cancer mortality. Due to the lack of sensitive and specific biomarkers for pancreatic cancer's development and progression, early diagnosis is difficult, the disease progresses rapidly, and the prognosis is poor. Due to its aggressive nature, prone to local growth in peripheral nerves and blood vessels and early distant metastasis, most patients are unable to undergo complete resection. Currently, treatments primarily used in clinical practice include radiotherapy, interventional therapy, supportive care, and immunotherapy to alleviate symptoms and prolong survival. Gemcitabine is currently the first-line drug for pancreatic cancer treatment. While gemcitabine exhibits significant anti-pancreatic cancer efficacy, it can also cause bone marrow suppression, rash, gastrointestinal side effects, and drug resistance, all of which can cause systemic damage. Therefore, the development of a highly effective anti-pancreatic cancer drug with minimal side effects is urgently needed.

[0004] Summary of the Invention

[0005] The purpose of this application is to provide a polysaccharide, a preparation method and application thereof, and an anti-tumor drug. The polysaccharide provided in this application has good anti-tumor activity, especially anti-pancreatic cancer activity, and good safety.

[0006] In order to achieve the above-mentioned invention objectives, this application provides the following technical solutions:

[0007] The present application provides a polysaccharide having the structure shown in Formula I:

[0008] In formula I, n1=0-6, n2=0-2, n3=0-3, and R is a C1-C10 alkoxy group.

[0009] Preferably, n1=1-5.

[0010] Preferably, n1=2-4.

[0011] Preferably, n2=0-1.

[0012] Preferably, n3=1-3.

[0013] Preferably, n3=2-3.

[0014] Preferably, R is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy or decyloxy.

[0015] Preferably, R is a C5-C10 alkoxy group.

[0016] Preferably, R is a linear alkoxy group.

[0017] Preferably, n1=3, n2=0, n3=3, and R is n-octyloxy.

[0018] The present application provides a method for preparing the polysaccharide described in the above technical solution, comprising the following steps:

[0019] Mixing compound 1-3, silver trifluoromethanesulfonate, p-methylphenylsulfonyl chloride and an organic solvent to perform a first activation reaction to obtain a first activated product system;

[0020] mixing the first activated product system with compound 1-4, and performing a first glycosylation coupling reaction to obtain a first coupling product system;

[0021] Mixing the first coupling product system, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride, and performing a second activation reaction to obtain a second activated product system;

[0022] The second activated product system is mixed with compound 1-5 to perform a second glycosylation coupling reaction to obtain compound 1-2;

[0023] The compound 1-2 is sequentially subjected to a debenzoylation reaction and a debenzylation-debenzylation reaction to obtain a polysaccharide having a structure shown in Formula I;

[0024] The structural formulas of Compound 1-3, Compound 1-4, Compound 1-5 and Compound 1-2 are shown below in sequence:

[0025] The n1, n2, n3 and R are defined as in Formula I.

[0026] Preferably, in the reaction raw materials of the first activation reaction, the molar ratio of the compound 1-3, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride is 1:(1.2-5):1.

[0027] Preferably, the temperature of the first activation reaction is -60 to -78°C, and the time is 2 to 10 minutes.

[0028] Preferably, in the reaction raw materials of the first glycosylation coupling reaction, the molar ratio of compound 1-3 to compound 1-4 is 1:(0.85-0.92).

[0029] Preferably, the first glycosylation coupling reaction comprises a first-stage reaction and a second-stage reaction in sequence; the temperature of the first-stage reaction is -60 to -78°C, and the time is 5 to 15 minutes; after the first-stage reaction, the temperature is naturally raised from the temperature of the first-stage reaction to carry out the second-stage reaction, and the time of the second-stage reaction is 1.5 to 2.5 hours.

[0030] Preferably, in the reaction raw materials of the second activation reaction, the molar ratio of the compound 1-4, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride is 1:(1.2-5):1.

[0031] Preferably, the temperature of the second activation reaction is -60 to -78°C, and the time is 2 to 10 minutes.

[0032] Preferably, in the reaction raw materials of the second glycosylation coupling reaction, the molar ratio of the compound 1-4 to the compound 1-5 is (0.8-0.85): (1-2).

[0033] Preferably, the second glycosylation coupling reaction comprises a first stage reaction and a second stage reaction in sequence; the temperature of the first stage reaction is -60 to -78°C, and the time is 5 to 15 minutes; after the first stage reaction, the temperature is naturally raised from the temperature of the first stage reaction to carry out the second stage reaction, and the time of the second stage reaction is 1.5 to 2.5 hours.

[0034] Preferably, the sequential debenzoylation and debenzylation-debenzylidene-debenzoylation of compound 1-2 comprises:

[0035] Mixing compound 1-2 with an organic solvent and performing a debenzoylation reaction under alkaline conditions to obtain a debenzoylation compound;

[0036] The debenzoyl compound, palladium-carbon catalyst, organic solvent and water are mixed to carry out debenzylation-debenzylidene reaction in a hydrogen atmosphere.

[0037] Preferably, the alkaline condition refers to a pH value of 9 to 10; the alkaline reagent providing the alkaline condition is a methanol solution of sodium methoxide.

[0038] Preferably, the debenzoylation reaction is carried out at a temperature of 10 to 30° C. and for a time of 5 to 24 hours.

[0039] Preferably, the temperature of the debenzylation-debenzylidene reaction is 10-30° C., the hydrogen pressure is 0.3-10 MPa, and the time is 5-24 h.

[0040] The present application provides the use of the polysaccharide described in the above technical solution in the preparation of anti-tumor drugs.

[0041] Preferably, the tumor is pancreatic cancer, gastric cancer, liver cancer or cervical cancer.

[0042] Preferably, the anti-tumor drug comprises the polysaccharide and a pharmaceutically acceptable carrier, and the mass fraction of the polysaccharide in the anti-tumor drug is 0.1 to 99.9%.

[0043] Preferably, the dosage form of the anti-tumor drug includes injection or oral tablet.

[0044] Preferably, the anti-tumor drug is administered orally, intravenously or subcutaneously.

[0045] The present application provides an anti-tumor drug comprising the polysaccharide described in the above technical solution and a pharmaceutically acceptable carrier.

[0046] Preferably, the mass fraction of polysaccharides in the anti-tumor drug is 0.1 to 99.9%.

[0047] The present application provides a glycan having a structure shown in Formula I. The glycan provided in the present application has good anti-tumor activity, especially anti-pancreatic cancer activity, and is safe. Test results show that the glycan provided in the present application has a good proliferation inhibitory effect on pancreatic cancer cells; it has no cytotoxicity towards the growth of hepatocytes, and exhibits a better safety profile than the positive drug gemcitabine. In addition, pancreatic cancer cells are sensitive to the glycan provided in the present application, overcoming the problem that pancreatic cancer cells have a certain resistance to gemcitabine. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG1 is a chemical structure diagram of the polysaccharide in this application;

[0049] FIG2 is a graph showing the preliminary evaluation results of the anti-pancreatic cancer activity of each compound;

[0050] FIG3 is a graph showing the effect of compound 2-34 on apoptosis and cell cycle of Panc-1 cells. DETAILED DESCRIPTION

[0051] The present application provides a polysaccharide having the structure shown in Formula I:

[0052] In formula I, n1=0-6, n2=0-2, n3=0-3, and R is a C1-C10 alkoxy group.

[0053] In the present application, in Formula I, n1=0-6, n2=0-2, and n3=0-3; n1 can specifically be 0, 1, 2, 3, 4, 5 or 6; n2 can specifically be 0, 1 or 2; and n3 can specifically be 0, 1, 2 or 3. In the present application, preferably, n1=1-5, n2=0-1, and n3=1-3; more preferably, n1=2-4, n2=0-1, and n3=2-3.

[0054] In the present application, R is a C1-C10 alkoxy group, preferably a C5-C10 alkoxy group; specifically, R can be a methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, or decyloxy group. In the present application, R is preferably a straight-chain alkoxy group.

[0055] In the present application, preferably, n1=3, n2=0, n3=3, and R is n-octyloxy.

[0056] The present application provides a method for preparing the polysaccharide described in the above technical solution, comprising the following steps:

[0057] Mixing compound 1-3, silver trifluoromethanesulfonate, p-methylphenylsulfonyl chloride and an organic solvent to perform a first activation reaction to obtain a first activated product system;

[0058] mixing the first activated product system with compound 1-4, and performing a first glycosylation coupling reaction to obtain a first coupling product system;

[0059] Mixing the first coupling product system, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride, and performing a second activation reaction to obtain a second activated product system;

[0060] The second activated product system is mixed with compound 1-5 to perform a second glycosylation coupling reaction to obtain compound 1-2;

[0061] The compound 1-2 is sequentially subjected to a debenzoylation reaction and a debenzylation-debenzylation reaction to obtain a polysaccharide having a structure shown in Formula I;

[0062] The structural formulas of Compound 1-3, Compound 1-4, Compound 1-5 and Compound 1-2 are shown below in sequence:

[0063] The n1, n2, n3 and R are defined as in Formula I.

[0064] In this application, unless otherwise specified, the raw materials used are commercially available products well known to those skilled in the art or are prepared using methods well known to those skilled in the art.

[0065] In the present application, compound 1-3, silver trifluoromethanesulfonate, p-toluenesulfonyl chloride and an organic solvent are mixed to carry out a first activation reaction to obtain a first activated product system. In the present application, the molar ratio of compound 1-3, silver trifluoromethanesulfonate (AgOTf) and p-toluenesulfonyl chloride (p-TolSCl) is preferably 1: (1.2-5): 1, more preferably 1: 2: 1; the silver trifluoromethanesulfonate and p-toluenesulfonyl chloride are used as activators. In the present application, the organic solvent is preferably dichloromethane (DCM); the present application does not specifically limit the amount of the organic solvent, as long as the reaction proceeds smoothly. In the present application, the first activation reaction is preferably carried out at The present invention is preferably carried out under the condition of the presence of molecular sieve; The molecular sieve is activated by burning under vacuum conditions and then cooled to room temperature for use. The molecular sieve is mixed with an organic solvent, then cooled to the temperature required for the first activation reaction, and silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride are added to carry out the first activation reaction. In the present application, the temperature of the first activation reaction is preferably -60 to -78°C, more preferably -75 to -78°C; the time is preferably 2 to 10 minutes, more preferably 5 minutes.

[0066] After the first activation reaction, the present application does not require post-treatment, and the obtained first activation product system is directly mixed with compound 1-4 to perform a first glycosylation coupling reaction to obtain a first coupling product system. In the present application, based on the amount of the compound 1-3, the molar ratio of the compound 1-3 to the compound 1-4 is preferably 1: (0.85 to 0.92), more preferably 1: 0.9. The present application preferably dissolves the compound 1-4 in an organic solvent and then adds it dropwise to the first activation product system to perform the first glycosylation coupling reaction. In the present application, the first glycosylation coupling reaction preferably includes a first-stage reaction and a second-stage reaction in sequence; the temperature of the first-stage reaction is preferably -60 to -78°C, more preferably -75 to -78°C, and the time of the first-stage reaction is preferably 5 to 15 minutes, more preferably 10 minutes; the present application preferably naturally heats up from the temperature of the first-stage reaction to carry out the second-stage reaction, and the time of the second-stage reaction is preferably 1.5 to 2.5 hours, more preferably 2 hours; the present application preferably reacts at a lower temperature first, which is beneficial to avoid the decomposition of active intermediates caused by temperature increase. In the embodiment of the present application, after the addition of the compound 1-4 is completed, specifically, the reaction is naturally heated up for 2 hours after stirring at -78°C for 10 minutes.

[0067] After the first glycosylation coupling reaction, the present application does not need to be post-processed, and the obtained first coupling product system, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride are directly mixed to carry out a second activation reaction to obtain a second activation product system. In the present application, based on the amount of the compound 1-4, the molar ratio of the compound 1-4, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride is preferably 1: (1.2 to 5): 1, more preferably 1: 2: 1. The present application preferably warms the first coupling product system to room temperature and stirs for 20 to 30 minutes, then cools it to the temperature required for the second activation reaction, adds silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride, and carries out a second activation reaction. In the present application, the conditions of the second activation reaction are preferably consistent with those of the first activation reaction and will not be repeated here.

[0068] After the second activation reaction, the present application does not require post-treatment, and the obtained second activation product system is directly mixed with compound 1-5 to perform a second glycosylation coupling reaction to obtain compound 1-2. In the present application, based on the amount of the compound 1-4, the molar ratio of the compound 1-4 to the compound 1-5 is preferably (0.8 to 0.85): (1 to 2), and more preferably 0.83: 1.05. The present application preferably dissolves the compound 1-5 in an organic solvent and then adds it dropwise to the second activation product system to perform a second glycosylation coupling reaction. In the present application, the conditions of the second glycosylation coupling reaction are preferably consistent with those of the first glycosylation coupling reaction and will not be repeated here. After the second glycosylation coupling reaction, the present application preferably adds triethylamine to quench the reaction, the reaction solution is filtered through diatomaceous earth, the filtrate is concentrated and separated by FLASH rapid preparative chromatography to obtain compound 1-2. In the examples of the present application, taking the preparation of compound 2-82 as an example, the mobile phase used in the FLASH rapid preparative chromatography is preferably a mixture of petroleum ether-ethyl acetate-dichloromethane, the volume fraction of the ethyl acetate is preferably 40%, and the volume fraction of dichloromethane is preferably 15%.

[0069] After obtaining compound 1-2, the present application sequentially subjects compound 1-2 to a debenzoylation (Bz) reaction and a debenzylation (Bn)-debenzylation reaction to obtain a polysaccharide having the structure shown in Formula I. The present application preferably mixes compound 1-2 with an organic solvent and conducts a debenzoylation reaction under alkaline conditions to obtain a debenzoylation compound; and then mixes the debenzoylation compound, a palladium-carbon catalyst, an organic solvent, and water, and conducts a debenzylation-debenzylation reaction under a hydrogen atmosphere to obtain a polysaccharide having the structure shown in Formula I. This is described in detail below.

[0070] In the present application, the organic solvents used for the debenzoylation reaction are preferably dichloromethane and methanol, and the volume ratio of dichloromethane to methanol is preferably (1.5-3~1):1, more preferably 2:1; the present application does not specifically limit the amount of the organic solvent used, as long as it can ensure the smooth progress of the reaction. In the present application, the alkaline conditions preferably refer to a pH value of 9 to 10; the alkaline reagent providing the alkaline conditions is preferably a methanol solution of sodium methoxide, and the concentration of the alkaline reagent is preferably 30wt%. In the present application, the temperature of the debenzoylation reaction is preferably 10 to 30°C, more preferably room temperature; the time is preferably 5 to 24h, more preferably 9h. After the debenzoylation reaction, the present application preferably adds a cation exchange resin to the obtained product system to neutralize it to a pH value of 7, filters to remove the cation exchange resin, and concentrates the filtrate and separates it by polystyrene gel exclusion chromatography (the eluent used is preferably ethyl acetate) to obtain a debenzoylation compound.

[0071] In the present application, the organic solvents used for the debenzylation-debenzylation reaction are preferably ethyl acetate and methanol, and the volume ratio of ethyl acetate to methanol is preferably 1: (1-3), more preferably 1: 2; the volume ratio of the organic solvent to water is preferably (2-6): 1, more preferably 3: 1; the present application has no special restrictions on the total amount of the organic solvent and water, as long as it can ensure the smooth progress of the reaction. In the present application, the mass content of palladium in the palladium-carbon catalyst is preferably 10% (denoted as 10% Pd / C); the present application has no special restrictions on the amount of the palladium-carbon catalyst, as long as it can ensure the smooth progress of the reaction. In the present application, the temperature of the debenzylation-debenzylation reaction is preferably 10-30°C, more preferably room temperature; the hydrogen pressure is preferably 0.3-10MPa, more preferably 0.4MPa; the time is preferably 5-24h, more preferably 9h. After the debenzylation-debenzylation reaction, the present application preferably filters the resulting product system through a microporous membrane to remove the palladium-carbon catalyst, and the filtrate is concentrated and separated by size exclusion chromatography on a dextran gel LH-20 (the eluent used is preferably methanol: water = 1:1 by volume) to obtain a polysaccharide having a structure shown in Formula I (as shown in Figure 1).

[0072] It should be noted that in the present application, when n3 in Formula I is 0, compound 1-4-2 (i.e., the hydroxyl group at position 5 of arabinose in compound 1-4 is replaced with benzyloxy OBn) and compound 1-5 are mainly used as reactants, and compound 1-2 is prepared according to the above technical scheme to prepare a polysaccharide having the structure shown in Formula I:

[0073] The following describes the method for preparing the reactants required for preparing the polysaccharide having the structure shown in Formula I in this application.

[0074] In this application, n3 in the compound 1-3 is 0 to 3, specifically divided into the following cases:

[0075] When n3 is 0, the compound 1-3 is deemed not to exist (i.e., it is not necessary to use the compound 1-3 to prepare the polysaccharide having the structure shown in Formula I);

[0076] When n3 is 1, the compound 1-3 is specifically compound 1-6;

[0077] When n3 is 2 to 3, the preparation method of the compound 1-3 preferably comprises the following steps: performing an activation reaction on the compound 1-6 in the presence of an activating agent, and then performing a glycosylation coupling reaction with the compound 1-7 to obtain a disaccharide compound (i.e., n3 is 2); performing an activation reaction on the disaccharide compound in the presence of an activating agent, and then performing a glycosylation coupling reaction with the compound 1-7 to obtain a disaccharide compound (i.e., n3 is 3); the structural formulas of the compounds 1-6 and 1-7 are shown below in sequence:

[0078] In the present application, the reagents and reaction conditions required for the activation reaction and glycosylation coupling reaction involved in the preparation of the compounds 1-3 are preferably consistent with the aforementioned technical solutions and will not be described in detail here.

[0079] In this application, the reaction formula for preparing compound 1-6 is shown below:

[0080] This application uses compound 2-52 as a raw material, and its hydroxyl groups at positions 2, 3, and 5 are protected by benzoylation. The methyl glycoside is then converted into a brominated sugar, namely compound 2-53. Through the action of 2, 6-lutidine (2, 6-Lutidine), it reacts with methanol to form an orthoester structure, locking positions 1 and 2 to obtain compound 2-54. The benzoyl groups at positions 3 and 5 are removed under alkaline conditions to obtain compound 2-55, and then the benzyl protection at positions 3 and 5 is performed under the action of NaH to obtain compound 2-56. Detailed description is given below. In this application, the preparation method of the compound 2-56 preferably includes the following steps:

[0081] Compound 2-52, acetyl bromide, methanol and dichloromethane are mixed to carry out bromination reaction to obtain a feed solution containing compound 2-53;

[0082] The solution containing compound 2-53, 2,6-lutidine and methanol are mixed to form an orthoester to obtain compound 2-54;

[0083] The compound 2-54 is mixed with methanol and subjected to a debenzoylation reaction under alkaline conditions to obtain compound 2-55;

[0084] The compound 2-55, benzyl bromide, sodium hydride and N,N-dimethylformamide are mixed to carry out a benzyl protection reaction to obtain compound 2-56.

[0085] In the present application, compound 2-52, acetyl bromide, methanol and dichloromethane are mixed and subjected to a bromination reaction to obtain a feed solution containing compound 2-53. In the present application, the molar ratio of compound 2-52, acetyl bromide and methanol is preferably 1:(1.5-3):(1.5-3), more preferably 1:3:2.7. In the present application, compound 2-52 is preferably mixed with dichloromethane, acetyl bromide is added under ice bath conditions, and then methanol is added dropwise. In the present application, the temperature of the bromination reaction is preferably 20-40°C, more preferably room temperature; the time is preferably 2-5h, more preferably 3h, and the time of the bromination reaction is counted from the completion of the dropwise addition of methanol.

[0086] After the bromination reaction, the present application does not require post-treatment, and the obtained feed solution containing compound 2-53, 2,6-lutidine and methanol are directly mixed to form an orthoester to obtain compound 2-54. In the present application, based on the amount of the compound 2-52 used, the molar ratio of the compound 2-52, 2,6-lutidine and methanol is preferably 1: (3 to 8): (5 to 20), more preferably 1: 5: 10. The present application preferably adds 2,6-lutidine and methanol to the feed solution containing compound 2-53 under ice bath conditions. In the present application, the temperature of the orthoester reaction is preferably 10 to 35°C, more preferably room temperature; the time is preferably 15 to 40 hours, more preferably 24 hours. After the orthoester reaction, the present application preferably adds dichloromethane to dilute the reaction solution, washes with water and saturated NaCl solution in sequence, dries over anhydrous Na2SO4, filters, concentrates the filtrate, and pumps for 50 to 60 minutes to obtain a light yellow oil, namely compound 2-54.

[0087] After obtaining compound 2-54, the present application mixes the compound 2-54 with methanol and performs a debenzoylation reaction under alkaline conditions to obtain compound 2-55. In the present application, the alkaline conditions preferably refer to a pH value of 9; the alkaline reagent providing the alkaline conditions is preferably a methanol solution of sodium methoxide, and the concentration of the alkaline reagent is preferably 30wt%. In the present application, the temperature of the debenzoylation reaction is preferably 20-40°C, more preferably room temperature; the time is preferably 8-24h, more preferably 12h. After the debenzoylation reaction, the present application preferably adds a cation exchange resin to the resulting product system to neutralize it to a pH value of 7, filters to remove the cation exchange resin, and concentrates the filtrate and separates it by column chromatography (the eluent used is preferably a mixture of petroleum ether, acetone, and Et3N, the volume ratio of petroleum ether to acetone is preferably 6:1, and the volume fraction of Et3N is preferably 0.2%) to obtain a light yellow oil, namely compound 2-55.

[0088] After obtaining compound 2-55, the present invention mixes compound 2-55, benzyl bromide, sodium hydride, and N,N-dimethylformamide to perform a benzyl protection reaction to obtain compound 2-56. In the present invention, based on the amount of compound 2-52 used, the molar ratio of compound 2-52, benzyl bromide, and sodium hydride is preferably 1:(2-8):(2-8), more preferably 1:4:4; the sodium hydride is preferably in the form of a sodium hydride mineral oil solution, and the mass fraction of the sodium hydride mineral oil solution is preferably 60%. The present invention preferably dissolves compound 2-55 in N,N-dimethylformamide, adds benzyl bromide under ice bath conditions, and then adds the sodium hydride mineral oil solution in batches. In the present application, the benzyl protection reaction preferably includes a first-stage reaction and a second-stage reaction in sequence; the temperature of the first-stage reaction is preferably -20 to 10°C, more preferably 0°C, and the time is preferably 1 to 4 hours, more preferably 1 to 2 hours; the temperature of the second-stage reaction is preferably 20 to 40°C, more preferably room temperature, and the time is preferably 8 to 24 hours, more preferably 12 hours. After the benzyl protection reaction, the present application preferably adds a saturated ammonium chloride solution to quench the reaction, concentrates the reaction solution, adds dichloromethane (DCM) to dilute it, and then washes it with water and saturated NaCl solution in sequence, dries it over anhydrous Na2SO4, filters it, and concentrates the filtrate and separates it by column chromatography (the eluent used is preferably a mixture of petroleum ether-ethyl acetate-Et3N, the volume ratio of petroleum ether to ethyl acetate is preferably 8:1, and the volume fraction of Et3N is preferably 0.2%) to obtain a light yellow oil, namely compound 2-56.

[0089] In the present application, compound 2-56 is subjected to the action of Lewis acid SnCl4 to open the orthoester ring, and electrophilically combines with p-methylthiophenol to finally obtain compound 1-6; specifically, the preparation method of compound 1-6 preferably includes the following steps:

[0090] Compound 2-26, p-methylthiophenol, SnCl4 and dichloromethane are mixed to carry out a ring-opening-electrophilic addition reaction to obtain compound 1-6.

[0091] In the present application, the molar ratio of the compound 2-26, p-methylthiophenol and SnCl4 is preferably 1: (2-10): (0.1-0.2), more preferably 1: 2: 0.1. In the present application, the ring-opening-electrophilic addition reaction is preferably carried out at The present invention is preferably carried out under the condition of the presence of molecular sieve; The molecular sieve is activated by burning under vacuum and then cooled to room temperature for use. The molecular sieve, compound 2-26 and p-methylthiophenol are stirred and mixed at room temperature for 10 to 20 minutes, cooled to the temperature required for the ring-opening-electrophilic addition reaction, and SnCl4 is added dropwise in batches. In the present application, the temperature of the ring-opening-electrophilic addition reaction is preferably -10 to 0°C, more preferably -5°C; the time is preferably 4 to 12 hours, more preferably 10 to 12 hours; the time of the ring-opening-electrophilic addition reaction is calculated from the completion of the SnCl4 addition. After the ring-opening-electrophilic addition reaction, the present application preferably adds triethylamine to quench the reaction, the reaction solution is filtered through diatomaceous earth to remove the molecular sieve, the filtrate is concentrated and separated by column chromatography (the eluent used is preferably petroleum ether: ethyl acetate = 20:1 by volume ratio) to obtain a colorless, transparent oily liquid, which is compound 1-6.

[0092] In this application, the reaction formula for preparing compound 1-7 is shown below:

[0093] This application starts with the key intermediate compound 2-55. Due to the presence of the orthoester ring, the reaction conditions are kept as acidic as possible to prevent the orthoester ring from opening. Therefore, under alkaline conditions, the TBS protecting group is selectively added to the 5-position to obtain compound 2-57. The exposed 3-position hydroxyl group is then benzyl-protected to obtain compound 2-58. The orthoester ring is opened under the action of the Lewis acid SnCl4, and electrophilically binds with p-methylthiophenol to obtain compound 2-59. Finally, in acetonitrile as a solvent, the TBS protecting group can be rapidly removed by reaction with the Lewis acid boron trifluoride etherate to obtain compound 1-7. The following steps are described in detail.

[0094] In the present application, the preparation method of compound 2-57 preferably comprises the following steps:

[0095] Compound 2-55, triethylamine, 4-dimethylaminopyridine (DMAP), tert-butyldimethylsilyl chloride (TBSCl) and pyridine were mixed and subjected to TBS protection reaction to obtain compound 2-57.

[0096] In the present application, the molar ratio of compound 2-55, triethylamine, 4-dimethylaminopyridine and tert-butyldimethylsilyl chloride is preferably 1:(2-10):(0-1):(1-1.1), more preferably 1:3.5:0.01:1.1. In the present application, compound 2-55 is preferably dissolved in pyridine, cooled to -5°C, triethylamine and 4-dimethylaminopyridine are added sequentially, and tert-butyldimethylsilyl chloride is added in batches. In the present application, the temperature of the TBS protection reaction is preferably 0-20°C, more preferably 5°C; the time is preferably 8-24 hours, more preferably 12 hours. After the TBS protection reaction, the present application preferably concentrates the reaction solution and separates it by column chromatography (the eluent used is preferably a mixture of petroleum ether, acetone and Et3N, the volume ratio of petroleum ether to acetone is preferably 6:1, and the volume fraction of Et3N is preferably 0.2%) to obtain an oily substance, namely compound 2-57.

[0097] In the present application, the preparation method of compound 2-58 preferably comprises the following steps:

[0098] Compound 2-57, benzyl bromide, sodium hydride and N,N-dimethylformamide are mixed and subjected to benzyl protection reaction to obtain compound 2-58.

[0099] In the present application, the molar ratio of compound 2-57, benzyl bromide, and sodium hydride is preferably 1:(1-2):(1-2), more preferably 1:1.5:1.3; the sodium hydride is preferably in the form of a sodium hydride mineral oil solution, and the mass fraction of the sodium hydride mineral oil solution is preferably 60%. In the present application, compound 2-57 is preferably dissolved in N,N-dimethylformamide, benzyl bromide is added under ice bath conditions, and then the sodium hydride mineral oil solution is added in batches. In the present application, the benzyl protection reaction preferably includes a first stage reaction and a second stage reaction in sequence; the temperature of the first stage reaction is preferably 0-10°C, more preferably 0-5°C, and the time is preferably 0.5-2 hours, more preferably 30-50 minutes; the temperature of the second stage reaction is preferably 10-30°C, more preferably room temperature, and the time is preferably 1-20 hours, more preferably 4 hours. After the benzyl protection reaction, the present application preferably adds H2O to quench the reaction, extracts with dichloromethane, washes the organic phase with a saturated NaCl solution, dries with anhydrous Na2SO4, filters, and concentrates the filtrate before separation by column chromatography (the eluent used is preferably a mixture of petroleum ether-ethyl acetate-Et3N, the volume ratio of petroleum ether to ethyl acetate is preferably 20:1, and the volume fraction of Et3N is preferably 0.2%) to obtain an oily substance, namely compound 2-58.

[0100] In the present application, the preparation method of compound 1-7 preferably comprises the following steps:

[0101] Compound 2-58, p-methylthiophenol, SnCl4 and dichloromethane are mixed to undergo a ring-opening-electrophilic addition reaction to obtain compound 2-59;

[0102] The compound 2-59, boron trifluoride etherate and acetonitrile are mixed and subjected to TBS protecting group removal reaction to obtain compound 1-7.

[0103] In the present application, compound 2-58, p-methylthiophenol, SnCl4 and dichloromethane are mixed and subjected to a ring-opening-electrophilic addition reaction to obtain compound 2-59. In the present application, the molar ratio of compound 2-58, p-methylthiophenol and SnCl4 is preferably 1: (1.5-5): (0.1-0.3), more preferably 1: 2: 0.1. In the present application, the ring-opening-electrophilic addition reaction is preferably carried out at The present invention is preferably carried out under the condition of the presence of molecular sieve; The molecular sieve is activated by burning under vacuum and then cooled to room temperature for use. Molecular sieves, compound 2-26 and p-methylthiophenol are stirred and mixed at room temperature for 10 to 20 minutes, cooled to -5°C, and SnCl4 is added dropwise in batches. In the present application, the temperature of the ring-opening-electrophilic addition reaction is preferably -20 to 0°C, more preferably -5°C; the time is preferably 10 to 24 hours, more preferably 12 hours; the time of the ring-opening-electrophilic addition reaction is counted from the completion of the SnCl4 addition. After the ring-opening-electrophilic addition reaction, the present application preferably adds triethylamine to quench the reaction, the reaction solution is filtered through diatomaceous earth to remove the molecular sieve, and the filtrate is concentrated and separated by column chromatography (the eluent used is preferably a mixture of petroleum ether-ethyl acetate-Et3N, the volume ratio of petroleum ether to ethyl acetate is preferably 100: 1, and the volume fraction of Et3N is preferably 0.2%) to obtain a colorless, transparent oily liquid, which is compound 2-59.

[0104] After obtaining compound 2-59, the present invention mixes the compound 2-59, boron trifluoride etherate and acetonitrile to carry out a TBS protection group removal reaction to obtain compound 1-7. In the present invention, based on the amount of the compound 2-58 used, the molar ratio of the compound 2-58 to boron trifluoride etherate is preferably 1:(1.1-2.0), more preferably 1:(1.1-1.5). The present invention preferably dissolves the compound 2-59 in acetonitrile and then adds boron trifluoride etherate dropwise under ice bath conditions. In the present invention, the temperature of the TBS protection group removal reaction is preferably -10 to 10°C, more preferably 0°C; the time is preferably 2 to 8 hours, more preferably 4 hours; the time of the TBS protection group removal reaction is calculated from the completion of the dropwise addition of boron trifluoride etherate. After the TBS protecting group removal reaction, the present application preferably adds triethylamine to quench the reaction, and the reaction solution is concentrated and separated by column chromatography (the eluent used is preferably a mixture of petroleum ether-ethyl acetate-Et3N, the volume ratio of petroleum ether to ethyl acetate is preferably 8:1, and the volume fraction of Et3N is preferably 0.2%) to obtain a colorless, transparent oily liquid, namely compound 1-7.

[0105] In the present application, the reaction formula for preparing the compound 1-4 (the wavy line in the structural formula represents a mixture of an α-configuration compound and a β-configuration compound) is as follows:

[0106] In this application, compound 2-68 and compound 2-43 are subjected to a glycosylation coupling reaction under the activation of an activator (p-TolSCl / AgOTf) to obtain a coupled disaccharide compound 2-69b, and the PMB protecting group is removed under the action of dichlorodicyanobenzoquinone (DDQ) to obtain a disaccharide hemiacetal (PMB-protected compound), which is then acetylated under the action of acetic anhydride to obtain compound 2-70. Finally, when SnCl4 is used as a Lewis acid, the acetyl group can be successfully converted into a p-methylphenylthio group. In addition, under this reaction condition, the TBS at position 5 of compound 2-70 will also be removed, which can shorten the subsequent TBS removal operation to obtain compound 1-4. The following is a detailed description.

[0107] In the present application, the preparation method of compound 2-69b preferably comprises the following steps:

[0108] Compound 2-43, 2,4,6-tri-tert-butylpyrimidine (TTBP), silver trifluoromethanesulfonate, p-methylphenylsulfonyl chloride and dichloromethane are mixed to perform an activation reaction to obtain an activated product system;

[0109] The activation production system is mixed with compound 2-68 and subjected to glycosylation coupling reaction to obtain compound 2-69b.

[0110] In the present application, compound 2-43, 2,4,6-tri-tert-butylpyrimidine (TTBP), silver trifluoromethanesulfonate, p-methylphenylsulfonyl chloride and dichloromethane are mixed for activation reaction to obtain an activated product system. In the present application, the molar ratio of the compound 2-43, 2,4,6-tri-tert-butylpyrimidine, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride is preferably 1: (1.5-5): (2-4): (1-1.5), more preferably 1: 2: 2.4: 1.2. In the present application, the activation reaction is preferably carried out at The present invention is preferably carried out under the condition of the presence of molecular sieve; The molecular sieve is activated by burning under vacuum conditions and then cooled to room temperature for use. Molecular sieves are mixed with dichloromethane, followed by the addition of 2,4,6-tri-tert-butylpyrimidine. The mixture is stirred at room temperature for 15 to 20 minutes, cooled to the desired activation temperature, and silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride are added to carry out the activation reaction. In this application, the activation reaction temperature is preferably -60 to -80°C, more preferably -78°C; the activation reaction time is preferably 5 to 10 minutes, more preferably 5 to 7 minutes.

[0111] After the activation reaction, the present application does not require post-treatment, and the obtained activation production system is directly mixed with compound 2-68 to carry out a glycosylation coupling reaction to obtain compound 2-69b. The present application preferably adds the compound 2-68 dropwise to the activation production system. In the present application, the glycosylation coupling reaction preferably includes sequentially carrying out a first-stage reaction and a second-stage reaction; the temperature of the first-stage reaction is preferably -60 to -78°C, more preferably -75 to -78°C, and the time of the first-stage reaction is preferably 15 to 25 minutes, more preferably 20 minutes; the present application preferably naturally raises the temperature from the temperature of the first-stage reaction to carry out the second-stage reaction, and the time of the second-stage reaction is preferably 1.5 to 2.5 hours, more preferably 2 hours; the present application preferably reacts at a lower temperature first, which is beneficial to avoid the decomposition of active intermediates caused by temperature increase. In the embodiment of the present application, after the addition of the compound 2-68 is completed, it is specifically stirred at -78°C for 10 minutes and then naturally heated to react for 2 hours. After the glycosylation coupling reaction, the present application preferably adds 0.2 mL of triethylamine to quench the reaction. The reaction solution is filtered through diatomaceous earth to remove the molecular sieves, and the filtrate is concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used is preferably a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate is preferably 40%) to obtain a light yellow oil, which is compound 2-69b.

[0112] In the present application, the preparation method of compound 1-4 preferably comprises the following steps:

[0113] Compound 2-69b, dichlorodicyanobenzoquinone (DDQ), dichloromethane and water are mixed to perform a PMB protection group removal reaction to obtain a PMB protection group-free compound;

[0114] The PMB-protected compound, acetic anhydride, 4-dimethylaminopyridine and pyridine are mixed and acetylated to obtain compound 2-70;

[0115] The compound 2-70, p-methylthiophenol, SnCl4 and dichloromethane are mixed to carry out substitution-deprotection reaction of TBS protecting group to obtain compound 1-4.

[0116] In the present application, compound 2-69b, dichlorodicyanobenzoquinone, dichloromethane and water are mixed to carry out a PMB protection group removal reaction to obtain a PMB protection group-removed compound. In the present application, the molar ratio of compound 2-69b to dichlorodicyanobenzoquinone is preferably 1:(1.2-2.5), more preferably 1:2; the volume ratio of dichloromethane to water is preferably (15-30):1, more preferably 19:1. In the present application, compound 2-69b, dichloromethane and water are preferably mixed, and then dichlorodicyanobenzoquinone is added in batches. In the present application, the temperature of the PMB protection group removal reaction is preferably 10-35°C, more preferably room temperature; the time is preferably 5-24h, more preferably 8h. After the PMB protection group removal reaction, the present invention filters the obtained product system through diatomaceous earth, dilutes the filtrate with dichloromethane, and washes with saturated NaHCO3 solution and saturated NaCl solution in sequence. The organic phase is dried over anhydrous Na2SO4, filtered, and the filtrate is concentrated to obtain the PMB protection group-removed compound.

[0117] After obtaining the deprotected PMB compound, the present invention mixes the deprotected PMB compound, acetic anhydride, 4-dimethylaminopyridine, and pyridine to perform an acetylation reaction to obtain compound 2-70. In the present invention, based on the amount of compound 2-69b used, the molar ratio of compound 2-69b, acetic anhydride, and 4-dimethylaminopyridine is preferably 1:(2-5):(0.1-0.5), more preferably 1:2:0.1. In the present invention, the deprotected PMB compound is preferably mixed with pyridine, followed by the addition of acetic anhydride and 4-dimethylaminopyridine. In the present invention, the acetylation reaction temperature is preferably 10-35°C, more preferably room temperature, and the reaction time is preferably 2-10 hours, more preferably 4 hours. After the acetylation reaction, the present application preferably concentrates the obtained product system under reduced pressure to remove pyridine, dilutes the reaction solution with dichloromethane, and washes with 1 mol / L hydrochloric acid, saturated NaHCO3 solution, and saturated NaCl solution, sequentially. The organic phase is dried over anhydrous Na2SO4, filtered, and the filtrate is concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used is preferably a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate is preferably 30%) to obtain a transparent oily liquid, which is compound 2-70.

[0118] After obtaining compound 2-70, the present invention mixes compound 2-70, p-methylthiophenol, SnCl4, and dichloromethane to perform a substitution-TBS protecting group removal reaction to obtain compound 1-4. In the present invention, based on the amount of compound 2-69b used, the molar ratio of compound 2-69b, p-methylthiophenol, and SnCl4 is preferably 1:(1.2-2.0):(0.3-0.5), more preferably 1:1.2:0.4. In the present invention, the present invention preferably mixes compound 2-70 with dichloromethane, adds p-methylthiophenol, and then cools the mixture to 0°C and adds SnCl4 dropwise. In the present invention, the temperature of the substitution-TBS protecting group removal reaction is preferably 0-10°C, more preferably 0-2°C, and the time is preferably 10-35 minutes, more preferably 25 minutes. After the substitution-deprotection reaction of the TBS protecting group, the present application preferably adds triethylamine to quench the reaction. The reaction solution is concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used is preferably a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate is preferably 60%) to obtain a yellow oil, which is compound 1-4.

[0119] In this application, the reaction formula for preparing compound 2-68 is shown below:

[0120] In this application, all benzoyl groups are removed from compound 2-60 to obtain compound 2-61, and 1,3-dichloro-1,1,3,3-tetraisopropyldimethylsiloxy ether (TBDPSCl2) is used to protect the hydroxyl groups at positions 3 and 5 in a silylation manner to obtain compound 2-62. The exposed hydroxyl group at position 2 is then benzoyl-protected to obtain compound 2-63. The silylation protecting group is removed under the action of tetrabutylammonium fluoride (TBAF) to obtain compound 2-64. The hydroxyl group at position 5 is then regioselectively protected with TBS to obtain compound 2-65. Subsequently, Lev protection is performed on the hydroxyl group at position 3 to obtain compound 2-66. Compound 2-67 is then obtained by a one-step glycosylation reaction with p-methoxybenzyl alcohol. Finally, the Lev protecting group is removed under the action of hydrazine acetate to obtain compound 2-68. Detailed description is given below.

[0121] In the present application, the preparation method of compound 2-63 preferably comprises the following steps:

[0122] Compound 2-60 is mixed with methanol and subjected to a debenzoylation reaction under alkaline conditions of sodium methoxide to obtain compound 2-61;

[0123] The compound 2-61, TIPDSCl2 and pyridine are mixed and subjected to a silylation reaction to obtain compound 2-62;

[0124] The compound 2-62, 4-dimethylaminopyridine, benzoyl chloride and pyridine are mixed and subjected to a benzoyl protection reaction to obtain compound 2-63.

[0125] In the present application, compound 2-60 is mixed with methanol and subjected to a debenzoylation reaction under alkaline conditions of sodium methoxide to obtain compound 2-61. In the present application, the alkaline conditions preferably refer to a pH value of 9 to 10; the alkaline reagent providing the alkaline conditions is preferably a methanol solution of sodium methoxide, and the concentration of the alkaline reagent is preferably 30 wt%. In the present application, the temperature of the debenzoylation reaction is preferably 10 to 30 ° C, more preferably room temperature; the time is preferably 6 to 24 h, more preferably 12 h. After the debenzoylation reaction, the present application preferably adds a cation exchange resin to the resulting product system to neutralize it to a pH value of 7, filters to remove the cation exchange resin, and concentrates the filtrate to obtain a colorless oil, which is compound 2-61.

[0126] After obtaining compound 2-61, the present invention mixes compound 2-61, TIPDSCl2, and pyridine and performs a silylation reaction to obtain compound 2-62. In the present invention, the molar ratio of compound 2-60 to TIPDSCl2 is preferably 1:(1.0-1.5), more preferably 1:1.1, based on the amount of compound 2-60 used. The present invention preferably mixes compound 2-61 with pyridine and adds TIPDSCl2 in batches under an ice bath. In the present invention, the silylation reaction temperature is preferably -20-10°C, more preferably 0°C, and the reaction time is preferably 5-24 hours, more preferably 12 hours. After the silylation reaction, the present invention preferably adds H2O to quench the reaction, extracts with dichloromethane, and dries the organic phase over anhydrous Na2SO4, filters, and concentrates the filtrate, which is then pumped through an oil pump for 2 hours to obtain compound 2-62.

[0127] After obtaining compound 2-62, the present application mixes the compound 2-62, 4-dimethylaminopyridine, benzoyl chloride and pyridine, and performs a benzoyl protection reaction to obtain compound 2-63. In the present application, based on the amount of the compound 2-60 used, the molar ratio of the compound 2-60, 4-dimethylaminopyridine and benzoyl chloride is preferably 1: (0-0.1): (1.1-2), more preferably 1: 0.01: 1.2. The present application preferably mixes the compound 2-62 with pyridine, adds 4-dimethylaminopyridine under ice bath conditions, and then adds benzoyl chloride dropwise in batches. In the present application, the benzoyl protection reaction preferably includes a first stage reaction and a second stage reaction in sequence; the temperature of the first stage reaction is preferably -10 to 0 ° C, more preferably -2 to 0 ° C, and the time is preferably 10 to 60 minutes, more preferably 30 minutes, and the time of the first stage reaction is calculated from the completion of the dropwise addition of benzoyl chloride; the temperature of the second stage reaction is preferably 0 to 30 ° C, more preferably room temperature, and the time is preferably 5 to 24 hours, more preferably 12 hours. After the completion of the benzoyl protection reaction, the present application preferably adds anhydrous methanol to quench the reaction, concentrates the reaction solution, adds dichloromethane to dilute the concentrate, washes with 1 mol / L hydrochloric acid, saturated NaHCO3 solution and saturated NaCl solution in sequence, dries over anhydrous Na2SO4, filters, and concentrates the filtrate and separates by column chromatography (the eluent used is preferably petroleum ether: ethyl acetate = 300: 1 by volume) to obtain an oily liquid, which is compound 2-63.

[0128] In the present application, the preparation method of compound 2-64 preferably comprises the following steps:

[0129] Compound 2-63, acetic acid, tetrabutylammonium fluoride and tetrahydrofuran are mixed and subjected to desilylation protecting group reaction to obtain compound 2-64.

[0130] In the present application, the molar ratio of compound 2-63, acetic acid, and tetrabutylammonium fluoride is preferably 1:(1.5-3.0):(1.5-3.0), more preferably 1:2.4:2.4. In the present application, compound 2-63 is preferably mixed with tetrahydrofuran, and acetic acid and tetrabutylammonium fluoride solutions in tetrahydrofuran are added sequentially under ice-bath conditions. In the present application, the desilylation reaction preferably comprises a first-stage reaction and a second-stage reaction. The first-stage reaction temperature is preferably -5-10°C, more preferably 0°C, and the reaction time is preferably 15-45 minutes, more preferably 30 minutes. The second-stage reaction temperature is preferably 10-30°C, more preferably room temperature, and the reaction time is preferably 2-6 hours, more preferably 4 hours. After the desilylation reaction, the product system is preferably concentrated and then separated by column chromatography (the eluent used is preferably dichloromethane:methanol = 40:1 by volume) to obtain a colorless oil, namely compound 2-64.

[0131] In the present application, the preparation method of compound 2-65 preferably comprises the following steps:

[0132] Compound 2-64, imidazole, tert-butyldimethylsilyl chloride (TBSCl) and dichloromethane are mixed and subjected to TBS protection reaction to obtain compound 2-65.

[0133] In the present application, the molar ratio of compound 2-64, imidazole and tert-butyldimethylsilyl chloride is preferably 1: (2 to 10): (1 to 1.1), more preferably 1: 3: 1.05. In the present application, compound 2-64 is preferably dissolved in dichloromethane, imidazole is added under ice bath conditions, and then tert-butyldimethylsilyl chloride is added in batches. In the present application, the TBS protection reaction preferably includes a first-stage reaction and a second-stage reaction in sequence; the temperature of the first-stage reaction is preferably -10 to 0°C, more preferably -2 to 0°C, and the time is preferably 0.5 to 2 hours, more preferably 1 hour; the temperature of the second-stage reaction is preferably 10 to 30°C, more preferably room temperature, and the time is preferably 1 to 10 hours, more preferably 3 hours. After the TBS protection reaction, the present application preferably adds dichloromethane to dilute the reaction solution, washes with water and saturated NaCl solution in sequence, dries over anhydrous Na2SO4, filters, and concentrates the filtrate before separation by FLASH rapid preparative chromatography (the mobile phase used is preferably a petroleum ether-acetone mixture, and the volume fraction of the acetone is preferably 10%) to obtain a white powder, which is compound 2-65.

[0134] In the present application, the preparation method of compound 2-66 preferably comprises the following steps:

[0135] Compound 2-65, 1-ethyl-3(3-dimethylpropylamine)carbodiimide (EDCI), 4-dimethylaminopyridine, levulinic acid and dichloromethane were mixed and subjected to Lev protection reaction to obtain compound 2-66.

[0136] In the present application, the molar ratio of compound 2-65, EDCI, 4-dimethylaminopyridine and levulinic acid is preferably 1: (1.5-5): (0.5-2): (1.2-2), more preferably 1: 2: 1: 1.5. The present application preferably mixes compound 2-65 with dichloromethane, and then adds EDCI, 4-dimethylaminopyridine and levulinic acid in sequence. In the present application, the temperature of the Lev protection reaction is preferably 10-35°C, more preferably room temperature, and the time is preferably 4-24h, more preferably 12h. After the Lev protection reaction, the present application preferably washes the resulting product system with saturated NaHCO3 solution, 1 mol / L hydrochloric acid and saturated NaCl solution in sequence, dries with anhydrous Na2SO4, filters, and concentrates the filtrate and separates it by column chromatography (the eluent used is preferably petroleum ether: acetone = 20: 1 by volume) to obtain a colorless transparent oil, which is compound 2-66.

[0137] In the present application, the preparation method of compound 2-67 preferably comprises the following steps:

[0138] Compound 2-66, 2,4,6-tri-tert-butylpyrimidine, p-methoxybenzyl alcohol, silver trifluoromethanesulfonate, p-methylphenylsulfonyl chloride and dichloromethane are mixed and subjected to a glycosylation reaction to obtain compound 2-67.

[0139] In the present application, the molar ratio of the compound 2-66, 2,4,6-tri-tert-butylpyrimidine, p-methoxybenzyl alcohol, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride is preferably 1:(2-4):(1.5-4):(1.5-3):(1-2), more preferably 1:2:2:2:1.5. In the present application, the glycosylation reaction is preferably carried out at The present invention is preferably carried out under the condition of the presence of molecular sieve; The molecular sieve is activated by burning under vacuum conditions and then cooled to room temperature for use. Molecular sieves are mixed with dichloromethane, and 2,4,6-tri-tert-butylpyrimidine and p-methoxybenzyl alcohol are added in sequence. After stirring at room temperature for 15 to 20 minutes, the temperature is lowered to the starting temperature required for the glycosylation reaction, and silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride are added. In the present application, the starting temperature of the glycosylation reaction is preferably -60 to -80°C, more preferably -78°C; the reaction is naturally heated at the starting temperature of the glycosylation reaction for 2 to 10 hours, more preferably 3 hours. After the glycosylation reaction, the present application preferably adds triethylamine to quench the reaction, the reaction solution is filtered through diatomaceous earth to remove the molecular sieve, the filtrate is concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used is preferably a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate is preferably 35%) to obtain a colorless oil, which is compound 2-67.

[0140] In the present application, the preparation method of compound 2-68 preferably comprises the following steps:

[0141] Compound 2-67, hydrazine acetate, tetrahydrofuran and methanol are mixed and subjected to a Lev protecting group removal reaction to obtain compound 2-68.

[0142] In the present application, the molar ratio of the compound 2-67 to hydrazine acetate is preferably 1: (3 to 20), more preferably 1: 5; the volume ratio of tetrahydrofuran to methanol is preferably (10 to 30): 1, more preferably 19: 1. The present application preferably mixes compound 2-67 tetrahydrofuran with methanol and then adds hydrazine acetate. In the present application, the temperature of the Lev protection group removal reaction is preferably 10 to 30°C, more preferably room temperature, and the time is preferably 2 to 10 hours, more preferably 4 hours. After the Lev protection group removal reaction, the present application preferably adds acetone and stirs at room temperature for 20 to 30 minutes to quench the reaction; the reaction solution is concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used is preferably a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate is preferably 30%) to obtain a light yellow oil, which is compound 2-68.

[0143] In this application, the reaction formula for preparing the compound 1-5 is as follows:

[0144] In the present application, the preparation method of the compound 1-5 preferably includes the following steps: subjecting the compound 1-10 to an activation reaction in the presence of an activating agent, and then subjecting the compound to a glycosylation coupling reaction with the compound 2-22 to obtain a first coupling compound; subjecting the first coupling compound to an activation reaction in the presence of an activating agent, and then subjecting the compound to a glycosylation coupling reaction with the compound 1-12 to obtain a second coupling compound; and subjecting the second coupling compound to a TBS protecting group removal reaction to obtain compound 1-5.

[0145] In the present application, the reagents and reaction conditions required for the activation reaction and glycosylation coupling reaction involved in the preparation of the compound 1-5 are preferably consistent with the aforementioned technical solution and will not be repeated here. In the present application, the second coupling compound is preferably mixed with an organic solvent, and a hydrogen fluoride pyridine solution is added dropwise under ice bath conditions, and the TBS protecting group removal reaction is carried out after the addition is completed. In the present application, the organic solvent is preferably tetrahydrofuran; the present application does not specifically limit the amount of the organic solvent, as long as the reaction proceeds smoothly. In the present application, the molar ratio of hydrogen fluoride to the second coupling compound in the hydrogen fluoride pyridine solution is preferably (4 to 6): 1, more preferably 5: 1. In the present application, the temperature of the TBS protecting group removal reaction is preferably 25 to 40°C, more preferably 35°C; the time is preferably 4 to 15h, more preferably 10h. After the TBS protecting group removal reaction, the present application preferably adds triethylamine to quench the reaction, concentrates under reduced pressure to remove the solvent, and then adds dichloromethane to dissolve the concentrate, washes with saturated NaHCO3 solution and saturated NaCl solution in sequence, and dries with anhydrous Na2SO4. The filtrate is filtered, and the filtrate is concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used is preferably a mixture of petroleum ether-ethyl acetate-dichloromethane, the volume fraction of ethyl acetate is preferably 70%, and the volume fraction of dichloromethane is preferably 15%) to obtain compound 1-5.

[0146] It should be noted that, in the present application, when n1 is 0, compound 2-22-1 and compound 1-12 are mainly used as reactants to prepare compound 1-5 with reference to the above technical scheme.

[0147] In this application, n1 in compounds 1-10 is 0 to 6, specifically divided into the following cases:

[0148] When n1 is 0, the compound 1-10 is deemed not to exist (i.e., there is no need to use compound 1-10 to prepare compound 1-5);

[0149] When n1 is 1, the compound 1-10 is specifically compound 2-43;

[0150] When n1 is 2 to 6, the preparation method of the compound 1-10 preferably comprises the following steps: performing an activation reaction on the compound 2-43 in the presence of an activating agent, and then performing a glycosylation coupling reaction with the compound 2-21 to obtain a coupling compound A (i.e., n1 is 2); performing an activation reaction on the coupling compound A in the presence of an activating agent, and then performing a glycosylation coupling reaction with the compound 2-21 to obtain a coupling compound B (i.e., n1 is 3); repeating the above activation reaction and the glycosylation coupling reaction with the compound 2-21 until the compound 1-10 of the desired length is obtained; the structural formula of the compound 2-21 is shown below:

[0151] In the present application, the reagents and reaction conditions required for the activation reaction and glycosylation coupling reaction involved in the preparation of the compounds 1-10 are preferably consistent with the aforementioned technical solutions and will not be described in detail here.

[0152] In this application, the reaction formula for preparing the compound 2-22 is shown below:

[0153] In this application, compound 2-45, protected at positions 4 and 6 by benzyl groups, is used as a donor and activated using a p-TolSCl / AgOTf activation system. It is then glycosylated with acceptor compound 2-48 at position 3, which has a Nap group attached to the 6th position, to obtain compound 2-48-2. Finally, the temporary protecting group Nap at position 6 is removed under the action of dichlorodicyanobenzoquinone to obtain compound 2-22. This is described in detail below.

[0154] In the present application, the preparation method of compound 2-22 preferably comprises the following steps:

[0155] Compound 2-45, silver trifluoromethanesulfonate, p-methylphenylsulfonyl chloride and dichloromethane are mixed to perform an activation reaction to obtain an activated product system; the activated product system is mixed with compound 2-48 to perform a glycosylation coupling reaction to obtain compound 2-22.

[0156] In the present application, the molar ratio of compound 2-45, silver trifluoromethanesulfonate, p-methylphenylsulfonyl chloride and compound 2-48 is preferably 1: (1.5-2): (0.95-1.05): (0.95-1.05), more preferably 1: 2: 1: 1. In the present application, the activation reaction is preferably carried out at The present invention is preferably carried out under the condition of the presence of molecular sieve; The molecular sieve is activated by burning under vacuum conditions and then cooled to room temperature for use. The molecular sieve is mixed with dichloromethane, then cooled to the temperature required for the activation reaction, and silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride are added to carry out the activation reaction. In the present application, the temperature of the activation reaction is preferably -60 to -80°C, more preferably -78°C; the time is preferably 5 to 10 minutes, more preferably 5 to 7 minutes. In the present application, compound 2-48 is preferably dissolved in dichloromethane and then added dropwise to the activated product system to carry out the glycosylation coupling reaction. In the present application, the glycosylation coupling reaction preferably includes a first stage reaction and a second stage reaction in sequence; the temperature of the first stage reaction is preferably -60 to -78°C, more preferably -75 to -78°C, and the time of the first stage reaction is preferably 5 to 15 minutes, more preferably 10 minutes; the present application preferably naturally raises the temperature from the first stage reaction to carry out the second stage reaction, and the time of the second stage reaction is preferably 2.5 to 3.5 hours, more preferably 3 hours; the present application preferably first carries out the reaction at a lower temperature to avoid the decomposition of the active intermediate caused by the increase in temperature. In the examples of the present application, after the addition of the compound 2-48 is completed, specifically, the mixture is stirred at -78°C for 10 minutes and then naturally heated to react for 3 hours. After the glycosylation coupling reaction, the present application preferably adds triethylamine to quench the reaction, the reaction solution is filtered through diatomaceous earth to remove the molecular sieve, and the filtrate is concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used is preferably a mixture of petroleum ether-ethyl acetate-dichloromethane, the volume fraction of ethyl acetate is preferably 30%, and the volume fraction of dichloromethane is preferably 15%) to obtain a white powder, namely compound 2-48-2.

[0157] In this application, the reaction formula for preparing compound 2-48 is shown below:

[0158] In the present application, a Nap protecting group is added to position 6 of compound 2-46 to obtain compound 2-47, and then the TBS protecting group at position 3 is removed under the action of Lewis acid to obtain compound 2-48. Detailed description is given below.

[0159] In the present application, the preparation method of compound 2-48 preferably comprises the following steps:

[0160] Compound 2-46, NapBr, sodium hydride, tetrahydrofuran and N,N-dimethylformamide are mixed and subjected to Nap protection reaction to obtain compound 2-47;

[0161] Compound 2-47, boron trifluoride etherate and acetonitrile were mixed and subjected to TBS protecting group removal reaction to obtain compound 2-48.

[0162] In the present application, compound 2-46, NapBr, sodium hydride, tetrahydrofuran and N,N-dimethylformamide are mixed and subjected to a Nap protection reaction to obtain compound 2-47. In the present application, the molar ratio of compound 2-46, NapBr and sodium hydride is preferably 1:(1.5-3):(1.2-3), more preferably 1:2:1.5; the volume ratio of tetrahydrofuran to N,N-dimethylformamide is preferably (5-10):1, more preferably 9:1. In the present application, the sodium hydride is preferably used in the form of a mineral oil solution of sodium hydride, and the mass fraction of the mineral oil solution of sodium hydride is preferably 60%. In the present application, compound 2-46, tetrahydrofuran and N,N-dimethylformamide are preferably mixed, NapBr is added under ice bath conditions, and then the mineral oil solution of sodium hydride is added in batches. In the present application, the temperature of the Nap protection reaction is preferably -10 to 10°C, more preferably 0°C; the time is preferably 2 to 10 hours, more preferably 5 hours. After the Nap protection reaction, the present application preferably adds a saturated NH4Cl solution to quench the reaction, extracts with dichloromethane, and the organic phase is dried over anhydrous Na2SO4, filtered, and the filtrate is concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used is preferably a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate is preferably 25%) to obtain a white powder, namely compound 2-47.

[0163] After obtaining compound 2-47, the present application mixes compound 2-47, boron trifluoride etherate and acetonitrile, and performs a TBS protecting group removal reaction to obtain compound 2-48. In the present application, the molar ratio of compound 2-47 to boron trifluoride etherate is preferably 1: (1 to 3), more preferably 1: 2. The present application preferably mixes compound 2-47 with acetonitrile and adds boron trifluoride etherate dropwise under ice bath conditions. In the present application, the temperature of the TBS protecting group removal reaction is preferably -10 to 10°C, more preferably 0°C; the time is preferably 3 to 10 minutes, more preferably 5 minutes. After the TBS protecting group removal reaction, the present application preferably adds triethylamine to quench the reaction, concentrates under reduced pressure to remove the solvent, and the residue is dissolved in dichloromethane, washed with water and saturated NaCl solution in sequence. The organic phase is dried over anhydrous Na2SO4, filtered, and the filtrate is concentrated and separated by column chromatography (the eluent used is preferably petroleum ether: ethyl acetate: dichloromethane = 4:1:4 by volume) to obtain a white powder, which is compound 2-48.

[0164] In this application, n2 in compound 1-12 is 0 to 2, specifically divided into the following cases:

[0165] When n2 is 0, the compound 1-12 is specifically HR, i.e., C1-C10 alkyl alcohol;

[0166] When n2 is 1, the compound 1-12 is specifically compound 1-18;

[0167] When n2 is 2, the preparation method of the compound 1-12 preferably comprises the following steps: performing an activation reaction on the compound 2-20 in the presence of an activating agent, and then performing a glycosylation coupling reaction with the compound 1-18 to obtain a coupling compound; mixing the coupling compound, hydrazine acetate and an organic solvent, and performing a deprotection reaction to obtain the compound 1-12 (n1 is 2); the structural formulas of the compound 2-20 and the compound 1-18 are shown below in sequence:

[0168] In the present application, the reagents and reaction conditions required for the activation reaction and glycosylation coupling reaction involved in the preparation of the compound 1-12 are preferably consistent with the aforementioned technical solutions and will not be repeated here. In the present application, the organic solvents used in the deprotection reaction are preferably tetrahydrofuran and methanol, and the volume ratio of tetrahydrofuran to methanol is preferably 10:1; the present application does not specifically limit the amount of the organic solvent, as long as the reaction proceeds smoothly. In the present application, the molar ratio of hydrazine acetate to the coupling compound is preferably (2 to 10): 1, more preferably 5: 1. In the present application, the temperature of the deprotection reaction is preferably 10 to 40°C, more preferably room temperature, and the time is based on ensuring that the raw materials are completely reacted. After the deprotection reaction, the present application preferably adds acetone to quench the reaction, concentrates the reaction solution, and separates it by column chromatography or rapid preparative chromatography to obtain compound 1-12.

[0169] In the present application, compound 2-21 is used as a starting material, and a Lev protecting group is added to position 6 to obtain compound 20; specifically, the preparation method of compound 2-20 preferably comprises the following steps:

[0170] Compound 2-21, diisopropylcarbodiimide (DIC), 4-dimethylaminopyridine, levulinic acid and dichloromethane are mixed and subjected to Lev protection reaction to obtain compound 2-20.

[0171] In the present application, the molar ratio of compound 2-21, diisopropylcarbodiimide (DIC), 4-dimethylaminopyridine and levulinic acid is preferably 1: (1-5): (0.1-1): (1.5-3), more preferably 1: 1.9: 0.6: 2. The present application preferably mixes compound 2-21 with dichloromethane, and adds 4-dimethylaminopyridine, levulinic acid and diisopropylcarbodiimide in sequence under ice bath conditions. In the present application, the Lev protection reaction preferably includes sequentially performing a first-stage reaction and a second-stage reaction; the temperature of the first-stage reaction is preferably -10 to 10°C, more preferably 0°C, and the time is preferably 10 to 60 minutes, more preferably 30 minutes; the temperature of the second-stage reaction is preferably 10 to 40°C, more preferably room temperature, and the time is preferably 0.5 to 5 hours, more preferably 1 hour. After the Lev protection reaction, the present application preferably adds a saturated NaHCO3 solution to quench the reaction, dilutes the reaction solution with dichloromethane, washes with a saturated NaHCO3 solution and a saturated NaCl solution in sequence, dries with anhydrous Na2SO4, filters, and concentrates the filtrate and separates by column chromatography (the eluent used is preferably petroleum ether: ethyl acetate: dichloromethane = 8:1:4 by volume) to obtain a white powder, which is compound 2-20.

[0172] The present application provides the use of the polysaccharide described in the above technical solution in the preparation of anti-tumor drugs.

[0173] In the present application, the tumor is preferably pancreatic cancer, gastric cancer, liver cancer or cervical cancer. In the present application, the anti-tumor drug comprises the polysaccharide described in the above technical solution and a pharmaceutically acceptable carrier. In the present application, the mass fraction of the polysaccharide in the anti-tumor drug is preferably 0.1 to 99.9%, more preferably 50 to 99%, and further preferably 80 to 95%. The present application does not specifically limit the specific type of the pharmaceutically acceptable carrier, and a pharmaceutically acceptable carrier well known to those skilled in the art can be used. In the present application, the dosage form of the anti-tumor drug preferably includes an injection or an oral tablet. In the present application, the administration method of the anti-tumor drug is preferably oral administration, intravenous injection or subcutaneous injection.

[0174] The present application provides an anti-tumor drug comprising the polysaccharide described in the above technical solution and a pharmaceutically acceptable carrier. The present application does not specifically limit the preparation method of the anti-tumor drug, and methods well known to those skilled in the art can be used.

[0175] The following will be combined with the embodiments of this application to clearly and completely describe the technical solutions in this application. Obviously, the embodiments described are only some of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0176] Unless otherwise specified, all chemical reagents used in this application are of analytical grade and do not require further purification before use; dry CH2Cl2, DMF and pyridine are prepared by atmospheric distillation of commercial solvents with CaH2; dry CH3OH is prepared by atmospheric distillation of a commercial solvent with a magnesium bar; dry toluene is prepared by distillation of metallic sodium; dry Et2O and THF are commercial solvents prepared by atmospheric distillation of sodium potassium alloy under argon protection. The molecular sieve was activated at a high temperature of 400°C in a muffle furnace and vacuum dried before use. All glycosylation reactions were protected by argon and carried out in dry glass reaction bottles with freshly redistilled solvents. The reaction was analyzed by TLC (Merck silica gel 60 F 254 (1.0554)) detection, the spots were observed under UV after development, the plate was directly baked and / or the color developer (Ce(NH4)2(NO3)6 (0.50 g, 0.9 mmol) and (NH4)6Mo7O 24 4H2O (24.00 g, 19.4 mmol) was dissolved in 5% aqueous sulfuric acid (500 mL) and soaked before identification on a hot plate. Column chromatography was performed using 200-300 mesh silica gel (Qingdao Ocean Chemical Plant). The gel column was packed with Bio-Beads S-X1, LH-20, and Toyopearl HW 55F (TOSOH). The solvent was removed by rotary evaporation in a water bath below 40°C under reduced pressure.

[0177] NMR data were recorded using a Bruker AVANCE III-400 or Bruker AVANCE III-600 NMR spectrometer at 25°C using CDCl3, CD3OD, and D2O as deuterated solvents. Chemical shifts were based on tetramethylsilane (TMS) as an internal standard or the chemical shift of the deuterated solvent (when the deuterated solvent itself does not contain TMS); 1 H, 13C NMR peak assignments were performed with the assistance of COSY, HSQC, and HMBC. High-resolution mass spectrometry was performed on Waters Xevo G2 Qtof and Waters SYNAPT G2-Si mass spectrometers. MALDI-TOF MS was performed on an AB SCIEX 5800 spectrometer, and specific rotations were measured using a Rudolph Research Analytical Autopol IV automatic polarimeter. Fully protected glycans were analyzed by GPC using a Waters e2659 instrument coupled to a 2414 RI detector (columns: HT2, HT3, HT4, 7.8 × 300 mm, elution solvent: THF, flow rate: 1 mL / min). Fully exposed glycans were analyzed by HPLC using a Thermo UltiMate 3000 liquid chromatograph equipped with an ELSD detector (columns: BRT102, BRT103, 4.6 × 250 mm, elution solvent: water, flow rate: 0.7 mL / min).

[0178] The following abbreviations represent the following: s = singlet; d = doublet; t = triplet; m = multiplet; dd = doublet of doublets; dt = doublet of triplets; td = triplet of doublets; br = broad.

[0179] Preparation Example 1 Preparation of Compound 1-6

[0180] (1) Compound 2-52 (20 g, 41.97 mmol, 1.0 eq) was dissolved in dry DCM (50 mL), acetyl bromide (9.3 mL, 125.92 mmol, 3.0 eq) was added under ice bath conditions, and anhydrous methanol (4.6 mL, 113.33 mmol, 2.7 eq) was added dropwise. The mixture was reacted at room temperature for 3 h. TLC showed that the reaction was complete to obtain a liquid containing compound 2-53. 2,6-dimethylpyridine (24.5 mL, 209.87 mmol, 5.0 eq) and anhydrous methanol (17 mL, 419.74 mmol, 10.0 eq) were added in sequence under ice bath conditions and the mixture was reacted at room temperature. After 24 hours, TLC showed that the reaction was complete, DCM (100 mL) was added to dilute the reaction solution, washed with water and saturated NaCl solution in sequence, dried over anhydrous Na2SO4, filtered, the filtrate was concentrated, and the oil pump was pumped for 1 hour to obtain a light yellow oil, namely compound 2-54; anhydrous methanol (150 mL) was added to dissolve compound 2-54, and a methanol solution of sodium methoxide (30 wt%) was added to adjust the pH value to 9. The reaction was allowed to proceed at room temperature for 12 hours. TLC showed that the reaction was complete, and a cation exchange resin was added to neutralize the mixture to a pH value of 7. The cation exchange resin was filtered to remove the cation exchange resin. The filtrate was concentrated and separated by column chromatography (the eluent used was a mixture of petroleum ether-acetone-Et3N, the petroleum ether-acetone-Et3N mixture was used as the eluent). The volume ratio of oily ether to acetone was 6:1, and the volume fraction of the Et3N was 0.2%) to obtain a light yellow oil, namely compound 2-55; the compound 2-55 was dissolved in DMF (100 mL), and benzyl bromide (19.94 mL, 167.90 mmol, 4.0 eq) was added under ice bath conditions, and a mineral oil solution of sodium hydride (6.72 g, 167.90 mmol, 4.0 eq) was added in batches (sodium hydride mass fraction was 60%). The reaction was carried out at 0 ° C for 1 h and then raised to room temperature (25 ° C) for 12 h. The reaction was completed by TLC monitoring, and a saturated ammonium chloride solution (20 mL) was added to quench the reaction. The reaction was concentrated. The mixture was diluted with DCM (200 mL), washed with water and saturated NaCl solution, dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and separated by column chromatography (the eluent used was a mixture of petroleum ether-ethyl acetate-Et3N, the volume ratio of petroleum ether to ethyl acetate was 8:1, and the volume fraction of Et3N was 0.2%) to give a light yellow oil, namely compound 2-56 (12.5 g, 66%, 1,2-O-(α-Methoxybenzylidene)-3-O-benzyl-5-O-benzyl-α-L-arabinofuranoside).

[0181] R f =0.25(petroleum ether / ethyl acetate,15:1). +39.0 (c 0.11, CHCl3); 1 H NMR (400MHz, CDCl3) δ7.58-7.51(m,2H,Ar),7.37-7.23(m,11H,Ar),7.16-7.11(m,2H,Ar), 6.19(d,J=4.3Hz,1H,H-1),4.93(d,J=4.3Hz,1H,H-2),4.59(d,J=12.0Hz,1H,PhCH2),4.55 (d,J=12.0Hz,1H,PhCH2),4.36-4.30(m,2H,H-4,PhCH2),4.20(d,J=12.0Hz,1H,PhCH2),3. 98(d,J=1.7Hz,1H,H-3),3.28(dd,J=9.9,6.4Hz,1H,H-5a),3.20-3.12(m,4H,H-5b,OCH3).

[0182] 13 C NMR(101MHz, CDCl3)δ137.96(Ar),137.18(Ar),136.55(Ar),129.30(Ar),128.53(Ar),128.34(Ar),128.15(Ar),127.98(Ar),127.89(Ar),127.67(Ar) ,127.63(Ar),126.34(Ar),123.17(Ar),106.20(C-1),85.38(C-2),84.68(C -4),82.83(C-3),73.19(PhCH2),71.60(PhCH2),69.95(C-5),50.71(OCH3).

[0183] HRMS(ESI)Calcd for C 27 H 28 NaO6[M+Na] + :471.1784,found:471.1782.

[0184] (2) Take a two-necked bottle, vacuum it together with a stirring bar, and then cool it down and introduce argon gas. Molecular sieves (6 g) were activated by burning with a blowtorch under vacuum conditions. After cooling to room temperature, argon was introduced and compound 2-56 (13.6 g, 30.32 mmol, 1.0 eq), p-methylthiophenol (7.53 g, 60.64 mmol, 2.0 eq) and dry DCM (60 mL) were added in sequence. The mixture was stirred at room temperature for 20 min and then cooled to -5 °C. SnCl4 (0.354 mL, 3.032 mmol, 0.1 eq) was added dropwise in batches and reacted at -5°C for 12 h. TLC showed that the reaction was complete. 2 mL of triethylamine was added to quench the reaction. The reaction solution was filtered through diatomaceous earth to remove the molecular sieves. The filtrate was concentrated and separated by column chromatography (the eluent used was petroleum ether: ethyl acetate = 20:1 by volume) to obtain a colorless, transparent oily liquid, which was compound 1-6 (12.4 g, 87%, p-Tolyl-2-O-benzoyl-3-O-benzyl-5-O-benzyl-1-thio-α-L-arabinofuranoside).

[0185] R f =0.34(petroleum ether / ethyl acetate,15:1). -108.3(c 0.13,CHCl3); 1 H NMR (400MHz, CDCl3) δ7.99-7.94(m,2H,Ar),7.56(t,J=7.4Hz,1H,Ar),7.47-7.37(m,5H,Ar),7.36-7.24(m,9H,A r),7.10(d,J=7.9Hz,2H,Ar),5.65(s,1H,H-1),5.56(t,J=1.5Hz,1H,H-2),4.81(d,J=12.0Hz,1H,PhCH2),4.61(d ,J=12.0Hz,1H,PhCH2),4.58-4.55(m,1H,H-4),4.55(d,J=11.7Hz,2H,PhCH2),4.49(d,J=12.0Hz,1H,PhCH2),4.1 4(d,J=5.4Hz,1H,H-3),3.71(dd,J=10.9,4.0Hz,1H,H-5a),3.65(dd,J=10.8,4.6Hz,1H,H-5b),2.31(s,3H,tolyl CH3).

[0186] 13C NMR(100MHz, CDCl3)δ165.42(C=O),137.98(Ar),137.61(Ar),137.52(Ar),133.40(Ar) ,132.45(Ar),130.62(Ar),129.82(Ar),129.73(Ar),129.36(Ar),128.47(Ar),128.42( Ar),128.32(Ar),127.96(Ar),127.85(Ar),127.64(Ar),127.61(Ar),91.62(C-1),83. 24(C-3),82.32(C-2),82.05(C-4),73.40(PhC),72.33(PhC),68.93(C-5),21.13(tolyl CH3).

[0187] HRMS(ESI)Calcd for C 33 H 32 NaO5S[M+Na] + :563.1868,found:563.1876.

[0188] Preparation Example 2 Preparation of Compound 1-7

[0189] (1) Compound 2-55 (13.4 g, 49.95 mmol, 1.0 eq) was dissolved in dry pyridine (90 mL), cooled to -5°C, triethylamine (24.30 mL, 174.83 mmol, 3.5 eq) and DMAP (61.03 mg, 0.499 mmol, 0.01 eq) were added in sequence, and TBSCl (8.28 g, 54.95 mmol, 1.1 eq) was added in batches and reacted at 5°C for 12 h. TLC showed that the reaction was complete and the concentration was 0.05. The reaction solution was condensed and separated by column chromatography (the eluent used was a mixture of petroleum ether-acetone-Et3N, the volume ratio of petroleum ether to acetone was 6:1, and the volume fraction of Et3N was 0.2%) to obtain an oily substance, namely compound 2-57 (16.5 g, 86%, 1,2-O-(α-Methoxybenzylidene)-5-O-tert-butyldimethylsilyl-α-L-arabinofuranoside).

[0190] R f =0.49(petroleum ether / acetone,3:1). +28.0(c 0.13,CHCl3); 1H NMR(400MHz,CDCl3)δ7.58(dt,J=7.2,3.3Hz,2H,Ar),7.42-7.31(m,3H,Ar),6.20(d,J=4.3Hz,1H,H-1),4.84(d,J=4.3Hz,1H,H-2),4.32(d,J=4.0Hz,1H,H-3),4.05(dd,J=9.6,5.5Hz,1H,H-4),3.48(dd,J=10.0,5.5Hz,1H,H-5a),3.25(t,J=9.8Hz,1H,H-5b),3.15(s,3H,CH3),1.97(d,J=4.2Hz,1H,OH),0.76(s,9H,TBS),-0.16(s,3H,TBS),-0.18(s,3H,TBS).

[0191] 13 C NMR(100MHz,CDCl3)δ136.19(Ar),129.33(Ar),128.14(Ar),126.31(Ar),123.02(Ar),110.01(PhC),106.11(C-1),88.92(C-4),87.11(C-2),76.17(C-3),63.00(C-5),50.78(OCH3),25.80(TBS),18.19(TBS),-5.58(TBS),-5.66(TBS).

[0192] HRMS(ESI)Calcd for C 19 H 30 O6Si[M+Na] + :405.1709,found:405.1706。

[0193] (2) Compound 2-57 (16.5 g, 43.13 mmol, 1.0 eq) was dissolved in DMF (150 mL). Benzyl bromide (7.68 mL, 64.70 mmol, 1.5 eq) and a mineral oil solution of sodium hydride (2.24 g, 56.07 mmol, 1.3 eq) (sodium hydride mass fraction: 60%) were added sequentially under ice bath conditions. The mixture was reacted at 0°C for 30 min and then raised to room temperature for 4 h. TLC showed that the reaction was complete. H2O (20 mL) was added to quench the reaction. The mixture was extracted twice with dichloromethane. The organic phases were combined and washed with saturated NaCl solution. times, dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and separated by column chromatography (the eluent used was a mixture of petroleum ether-ethyl acetate-Et3N, the volume ratio of petroleum ether to ethyl acetate was 20:1, and the volume fraction of Et3N was 0.2%) to obtain an oily substance, namely compound 2-58 (17.4 g, 85%, 1,2-O-(α-Methoxybenzylidene)-3-O-benzyl-5-O-tert-butyldimethylsilyl-α-L-arabinofuranoside).

[0194] R f =0.38(petroleum ether / ethyl acetate,15:1). +29.3 (c 0.44, CHCl3); 1 H NMR (400MHz, CDCl3) δ7.61-7.54(m,2H,Ar),7.41-7.27(m,8H,Ar),6.20(d,J=4.3Hz,1H ,H-1),4.94(d,J=4.3Hz,1H,H-2),4.59(d,J=12.0Hz,1H,PhCH2),4.55(d,J=12.0Hz,1H PhCH2),4.23(dd,J=9.8,5.4Hz,1H,H-4),4.05(s,1H,H-3),3.46(d,J=10.0Hz,1H,H-5a),3.20(t ,J=9.9Hz,1H,H-5b),3.15(s,3H,OCH3),0.75(s,9H,TBS),-0.18(s,3H,TBS),-0.21(s,3H,TBS).

[0195] 13C NMR(100MHz, CDCl3)δ137.34(Ar),136.26(Ar),129.32(Ar),128.52(Ar),128.15(Ar),127.91(Ar),127.78(Ar),126.88(Ar),126.30(Ar),122.94(PhC) ,106.43(C-1),86.67(C-4),85.39(C-2),82.62(C-3),71.43(PhCH2),62.80 (C-5),50.80(-OCH3),25.81(t-Bu),18.15(t-Bu),-5.62(CH3),-5.64(CH3).

[0196] HRMS(ESI)Calcd for C 26 H 36 O6Si[M+Na] + :459.2179,found:459.2186.

[0197] (3) Take a two-necked bottle, vacuum it together with the stirring bar, and then add argon gas after cooling. Molecular sieves (6 g) were activated by burning with a blowtorch under vacuum conditions. After cooling to room temperature, argon was introduced and compound 2-58 (11 g, 23.27 mmol, 1.0 eq), p-methylthiophenol (5.78 g, 46.55 mmol, 2.0 eq) and dry DCM (60 mL) were added in sequence. The mixture was stirred at room temperature for 20 min, cooled to -5 ° C, and SnCl4 (0.272 mL, 2.33 mmol, 0.1 eq) was added dropwise in batches. The mixture was reacted at -5 ° C for 12 h. TLC showed that the reaction was complete. 2 mL of triethylamine was added to quench the reaction. The reaction solution was filtered through diatomaceous earth to remove the molecular sieves. The filtrate was concentrated and separated by column chromatography (the The eluent was a mixture of petroleum ether-ethyl acetate-Et3N, the volume ratio of petroleum ether to ethyl acetate was 100:1, and the volume fraction of Et3N was 0.2%) to obtain a colorless transparent oily liquid, namely compound 2-59; the compound 2-59 was dissolved in anhydrous acetonitrile (60 mL), and boron trifluoride etherate (3.16 mL, 1.1 eq) was added dropwise under ice bath conditions, and the reaction was carried out at 0°C for 4 h. TLC showed that the reaction was complete, and 5 mL of triethylamine was added to quench the reaction. The reaction solution was concentrated and separated by column chromatography (the eluent was a mixture of petroleum ether-ethyl acetate-Et3N, the volume ratio of petroleum ether to ethyl acetate was 8:1, The volume fraction of Et3N is 0.2%) to obtain a colorless transparent oily liquid, namely compound 1-7 (6.8 g, two-step yield 65%, p-Tolyl-2-O-benzoyl-3-O-benzyl-1-thio-α-L-arabinofuranoside).

[0198] R f =0.24(petroleum ether / ethyl acetate,4:1). -138.1(c 0.13,CHCl3); 1<h2 style=";text-align:left;direction:ltr">H NMR (400MHz,CDCl3)δ8.03-7.98(m,2H,Ar),7.61-7.55(m,1H,Ar),7.44(dt,J=7.5,3.6Hz,5H,Ar),7.39-7.26(m,6H,Ar),7.13(d,J=7.9Hz,2H,Ar),5.62(s,1H,H-1),5.55(t,J=1.6Hz,1H,H-2),4.85(d ,J=12.0Hz,1H,PhCH2),4.63(d,J=12.0Hz,1H,PhCH2),4.52-4.48(m,1H,H-4),4.17(dd,J=5.6,0.7H z,1H,H-3),3.90(dd,J=12.3,2.9Hz,1H,H-5a),3.70(dd,J=12.3,3.7Hz,1H,H-5b),2.32(s,3H,tolyl CH3).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0199] <h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> C NMR(101MHz,CDCl3)δ165.36(C=O),137.97(Ar),137.42(Ar),133.54(Ar),132.81(Ar),130.27(Ar),129.83(Ar),129.78(Ar),129.28(Ar),12 8.55(Ar),128.50(Ar),127.97(Ar),127.92(Ar),91.86(C-1),83.10(C-4),82.71(C-3),82.33(C-2),72.57(PhCH2),61.67(C-5),21.15(tolyl CH3).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0200] <h2 style=";text-align:left;direction:ltr"> HRMS(ESI)Calcd for C<h2 style=";text-align:left;direction:ltr"> 26 <h2 style=";text-align:left;direction:ltr"> H<h2 style=";text-align:left;direction:ltr"> 26 <h2 style=";text-align:left;direction:ltr"> O5S[M+Na]<h2 style=";text-align:left;direction:ltr"> + <h2 style=";text-align:left;direction:ltr"> :473.1399,found:473.1399.<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0201] <h2 style=";text-align:left;direction:ltr"> 1-4<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0202] (1) Compound 2-60 (130 g, 228.62 mmol, 1.0 eq) was dissolved in anhydrous methanol (450 mL) to prepare a suspension. A methanol solution of sodium methoxide (30 wt%) was added dropwise under ice bath conditions to adjust the pH to 9. The mixture was reacted at room temperature for 12 h. TLC showed that the reaction was complete. A cation exchange resin was added to adjust the pH to 7. The cation exchange resin was removed by filtration. The filtrate was concentrated to obtain a colorless oil, which was compound 2-61. The compound 2-61 was dissolved in anhydrous pyridine (350 mL) and ice bath conditions to obtain a suspension. 1,3-Dichloro-1,1,3,3-tetraisopropyldimethylsiloxy ether (TIPDSCl2, 71.41 mL, 251.48 mmol, 1.1 eq) was added in batches under bath conditions, and the reaction was carried out at 0°C for 12 h. TLC showed that the reaction was complete, and H2O (100 mL) was added to quench the reaction. The organic phases were combined, dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and pumped for 2 h to obtain a yellow oil, which was a crude product of compound 2-62; the compound 2 was dissolved in anhydrous pyridine (300 mL). -62 crude product, DMAP (279.30 mg, 2.29 mmol, 0.01 eq) was added under ice bath condition, and benzoyl chloride (31.87 mL, 274.34 mmol, 1.2 eq) was added dropwise in batches. The reaction was carried out at 0 ° C for 30 min and then the temperature was raised to room temperature for 12 h. TLC showed that the reaction was complete. Anhydrous methanol (50 mL) was added to quench the reaction, and the reaction solution was concentrated. Dichloromethane (400 mL) was added to dilute the concentrate, and 1 mol / L hydrochloric acid, saturated NaHCO3 solution and saturated Na The residue was washed with Cl solution, dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and separated by column chromatography (the eluent used was petroleum ether:ethyl acetate = 300:1 by volume) to obtain an oily liquid, namely compound 2-63 (81 g, three-step yield 59%, p-Tolyl-2-O-benzoyl-3,5-O-(tetraisopropylsiloxane-1,3-diyl)-1-thio-α-L-arabinofuranoside).

[0203] R f =0.58(petroleum ether / acetone,10:1). -43.2(c 0.12,CHCl3); 1H NMR(400MHz,CDCl3)δ8.11-8.04(m,2H,Ar),7.66-7.58(m,1H,Ar),7.49(dd,J=10.4,4.8Hz,4H,Ar),7.13(d,J=7.9Hz,2H,Ar),5.64(dd,J=5.2,3.7Hz,1H,H-2),5.51(d,J=3.7Hz,1H,H-1),4.61(dd,J=7.9,5.3Hz,1H,H-3),4.27(dt,J=7.7,3.7Hz,1H,H-4),4.14(dd,J=12.6,3.2Hz,1H,H-5a),4.07(dd,J=12.7,4.5Hz,1H,H-5b),2.34(s,3H,tolylCH3),1.21-1.07(m,22H,i-Pr),1.06-1.01(m,3H,i-Pr),1.00-0.94(m,3H,i-Pr).

[0204] 13 C NMR(101MHz,CDCl3)δ165.44(PhC=O),137.52(Ar),133.37(Ar),132.26(Ar),130.69(Ar),129.78(Ar),129.65(Ar),129.43(Ar),128.47(Ar),89.71(C-1),83.24(C-2),80.99(C-4),75.66(C-3),61.48(C-5),21.11(tolyl CH3),17.49(i-Pr),17.37(i-Pr),17.03(i-Pr),16.96(i-Pr),16.95(i-Pr),16.92(i-Pr),13.52(i-Pr),13.23(i-Pr),12.89(i-Pr),12.53(i-Pr).

[0205] HRMS(ESI)Calcd for C 31 H 50 NO6SSi2[M+NH4] + :620.2897,found:620.2905。

[0206] (2) Compound 2-63 (104 g, 172.49 mmol, 1.0 eq) was dissolved in dry THF (200 mL). Acetic acid (23.70 mL, 413.98 mmol, 2.4 eq) and tetrabutylammonium fluoride (413.98 mmol, 2.4 eq) in tetrahydrofuran (413.98 mL) were added sequentially under ice bath conditions. The mixture was reacted at 0°C for 30 min and then raised to room temperature for 4 h. TLC showed that the reaction was complete. The reaction solution was concentrated and separated by column chromatography (the eluent used was dichloromethane:methanol = 40:1 by volume) to obtain a colorless oil, namely compound 2-64 (57.2 g, 92%, p-Tolyl-2-O-benzoyl-1-thio-α-L-arabinofuranoside).

[0207] R f =0.58(petroleum ether / acetone,1:1). -107.2 (c 0.29, CHCl3); 1 H NMR (400MHz, CDCl3) δ8.08-8.01(m,2H,Ar),7.68-7.58(m,1H,Ar),7.50-7.44(m, 4H,Ar),7.17(d,J=7.9Hz,2H,Ar),5.70(d,J=3.1Hz,1H,H-1),5.18(t,J=3.4Hz,1H ,H-2),4.37(dt,J=6.8,3.3Hz,1H,H-4),4.31(dd,J=7.4,3.6Hz,1H,H-3),3.98(d d,J=12.4,2.9Hz,1H,H-5a),3.83(dd,J=12.4,3.8Hz,1H,H-5b),2.36(s,1H,tolyl CH3).

[0208] 13 C NMR(100MHz,CDCl3)δ167.29(Ar),138.27(Ar),133.81(Ar),132.88(Ar),129.91(Ar),129.58(Ar),12 8.84(Ar),128.59(Ar),89.66(C-1),87.22(C-2),82.80(C-4),76.27(C-3),61.33(C-5),21.18(tolyl CH3).

[0209] HRMS(ESI)Calcd for C 19 H 20 O5S[M+Na] +:383.0929,found:383.0923.

[0210] (3) Compound 2-64 (10 g, 27.75 mmol, 1.0 eq) was dissolved in dry DCM (60 mL). Imidazole (5.67 g, 83.24 mmol, 3.0 eq) was added in an ice bath. TBSCl (4.39 g, 29.13 mmol, 1.05 eq) was added in batches. The mixture was reacted at 0 °C for 1 h and then warmed to room temperature for 3 h. TLC showed that the reaction was complete. DCM (100 mL) was added to dilute the reaction solution, which was washed with water and saturated NaCl solution in turn, dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a petroleum ether-acetone mixture, the volume fraction of the acetone was 10%) to obtain a white powder, namely compound 2-65 (12.1 g, 92%, p-Tolyl-2-O-benzoyl-5-O-tert-butyldimethylsiliyl-1-thio-α-L-arabinofuranoside).

[0211] R f =0.72(petroleum ether / acetonre,1:1). -56.6 (c 0.20, CHCl3); 1 H NMR (400MHz, CDCl3) δ8.03 (dd, J=8.3, 1.1Hz, 2H, Ar), 7.66-7.56 (m, 1H, Ar), 7.46 (t, J=7.7Hz, 4H, Ar), 7.13 (d, J=7.9Hz, 2H,Ar),5.64(d,J=3.7Hz,1H,H-1),5.13(t,J=3.6Hz,1H,H-2),4.31-4.23(m,2H,H-3,H-4),3.91(dd,J=11.3,3.3Hz,1H, H-5a),3.85(dd,J=11.3,3.9Hz,1H,H-5b),3.34(s,1H,OH),2.34(s,3H,SPhCH3),0.87(s,9H,TBS),0.06(s,3H,TBS),0.06(s,3H,TBS).

[0212] 13C NMR(100MHz, CDCl3)δ167.29(C=O),137.92(Ar),133.69(Ar),132.67(Ar),129.91(Ar),129.85(Ar),129.74(Ar),1 29.00(Ar),128.5(Ar),89.28(C-1),87.00(C-2),83.18(C-3),76.89(C-4),62.60(C-5),25.85(TBS),21.13(tolyl CH3),18.31(TBS),-5.33(TBS),-5.38(TBS).

[0213] HRMS(ESI)Calcd for C 25 H 34 O5SSi[M+Na] + :497.1794,found:497.1801.

[0214] (4) Compound 2-65 (12.5 g, 26.33 mmol, 1.0 eq) and DCM (150 mL) were added to an eggplant-shaped flask. After dissolution, EDCI (10.1 g, 52.67 mmol, 2.0 eq), DMAP (3.22 g, 26.33 mmol, 1.0 eq) and levulinic acid (4.59 g, 39.50 mmol, 1.5 eq) were added in sequence. The reaction was carried out at room temperature for 12 h. TLC showed that the reaction was complete. The mixture was washed with saturated NaHCO3 solution and 1 mol / L The reaction mixture was washed three times with hydrochloric acid and saturated NaCl solution, dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and separated by column chromatography (the eluent used was petroleum ether:acetone = 20:1 by volume) to give a colorless transparent oil, namely compound 2-66 (14 g, 93%, p-Tolyl-2-O-benzoyl-3-O-levulinyl-5-O-tert-butyldimethylsilyl-thiol-α-L-arabinofuranoside).

[0215] R f =0.31(petroleum ether / ethyl acetate,5:1). -99.7(c 0.13,CHCl3). 1H NMR (400MHz, CDCl3) δ8.08-8.00(m,2H,Ar),7.63-7.54(m,1H,Ar),7.49-7.39(m, 4H,Ar),7.14(d,J=7.9Hz,2H,Ar),5.64(d,J=2.5Hz,1H,H-1),5.49(t,J=2.4Hz,1H ,H-2),5.38(dd,J=5.0,2.1Hz,1H,H-3),4.40(dd,J=9.1,4.1Hz,1H,H-5),3.96-3 .93(m,2H,H-5),2.89-2.75(m,2H,Lev),2.74-2.59(m,2H,Lev),2.35(s,3H,tolyl CH3),2.21(s,3H,Lev),0.91(s,9H,TBS),0.09(s,3H,TBS),0.09(s,3H,TBS).

[0216] 13 C NMR(101MHz, CDCl3)δ206.18(Lev),171.75(Lev),165.37(C=O),137.87(Ar),133.45(Ar),132.78(Ar),129.91(Ar),129.86(Ar),129.74(Ar),129.20 (Ar),128.41(Ar),90.96(C-1),82.98(C-4),82.22(C-2),77.31(C-3),62. 74(C-5),37.93(Lev),29.78(Lev),27.98(Lev),25.87(TBS),21.14(tolyl CH3),18.33(TBS),-5.34(TBS),-5.41(TBS).

[0217] HRMS(ESI)Calcd for C 30 H 40 NaO7SSi[M+Na] + :595.2162,found:595.2164.

[0218] (5) Take two bottles, vacuum bake the bottles together with the stirring rod, and then introduce argon gas after cooling. Molecular sieves (5 g) were activated by blowtorch baking under vacuum conditions. After cooling to room temperature, compound 2-66 (1 g, 1.75 mmol, 1.0 eq) was dissolved in DCM (30 mL) and added to the reaction flask. TTBP (867.39 mg, 3.49 mmol, 2.0 eq) and p-methoxybenzyl alcohol (482.43 mg, 3.49 mmol, 2.0 eq) were added in sequence. After stirring at room temperature for 20 min, the temperature was lowered to -78 ° C. AgOTf (897.13 mg, 3.49 mmol, 2.0 eq) and p-TolSCl (400 μL, 2.62 mmol, 1.5 eq) were added to the reaction flask. ℃ as the starting temperature, and the temperature was naturally raised to react for 3 hours. TLC showed that the reaction was complete, and 2 mL of triethylamine was added to quench the reaction. The reaction solution was filtered through diatomaceous earth to remove the molecular sieves. The filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate was 35%) to obtain a colorless oil, which was compound 2-67 (864 mg, 84%, p-Methoxybenzyl-2-O-benzoyl-3-O-levulinyl-5-O-tert-butyldimethylsilyl-α-L-arabinofuranoside).

[0219] -43.0(c 0.13,CHCl3). 1 H NMR (400MHz, CDCl3) δ8.07-8.00(m,2H,Ar),7.58(dd,J=10.5,4.3Hz,1H,Ar),7.44(t,J=7.7Hz,2H,Ar),7.34(d,J=8.6Hz,2H,Ar) ,6.94-6.87(m,2H,Ar),5.36(d,J=1.3Hz,1H,H-2),5.28(dd,J=5.3,1.1Hz,1H,H-3),5.24(s,1H,H-1),4.76(d,J=11.6Hz,1H,PMB CH2),4.55(d,J=11.6Hz,1H,PMB CH2),4.22(dd,J=8.8,4.9Hz,1H,H-4),3.96(dd,J=11.3,3.6Hz,1H,H-5),3.91(dd,J=11.3,4.9Hz,1H,H-5),3.82(s,3H,PMB CH3),2.85-2.71(m,2H,Lev),2.70-2.56(m,2H,Lev),2.16(s,3H,Lev),0.92(s,9H,TBS),0.11(s,6H,TBS).

[0220] 13 C NMR(101MHz, CDCl3)δ206.22(Lev),171.86(Lev),165.40(Lev),159.29(Ar),133.36(Ar),129.88(Ar),129.59(Ar), 129.43(Ar),129.33(Ar),128.37(Ar),113.83(Ar),104.56(C-1),83.13(C-4),82.43(C-2),77.23(C-3),68.40(PMB CH2),62.80(C-5),55.27(PMB CH3),37.87(Lev),29.75(Lev),27.94(Lev),25.91(TBS),18.40(TBS),-5.27(TBS),-5.34(TBS).

[0221] HRMS(ESI)Calcd for C 31 H 46 NO9Si[M+NH4] + :604.2942,found:604.2945.

[0222] (6) Compound 2-67 (580 mg, 988.49 μmol, 1.0 eq), tetrahydrofuran (18 mL) and methanol (2 mL) were added to an eggplant-shaped flask, and after dissolution, hydrazine acetate (455.19 mg, 4.94 mmol, 5.0 eq) was added. The mixture was reacted at room temperature for 4 h. TLC showed that the reaction was complete. 2 mL of acetone was added and stirred at room temperature for 30 min to quench the reaction. The reaction solution was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a mixture of petroleum ether and ethyl acetate, and the volume fraction of the ethyl acetate was 30%) to obtain a light yellow oil, which was compound 2-68 (430 mg, 89%, p-Methoxybenzyl-2-O-benzoyl-5-O-tert-butyldimethylsilyl-α-L-arabinofuranoside).

[0223] -98.5(c 0.13,CHCl3).R f =0.70(petroleum ether / ethyl acetate,2:1). 1H NMR (400MHz, CDCl3) δ8.02-7.97(m,2H,Ar),7.62-7.54(m,1H,Ar),7.49-7.38(m,2H,Ar),7.33-7.27(m,2H ,Ar),6.92-6.85(m,2H,Ar),5.29(s,1H,H-1),5.15(dd,J=2.5,0.9Hz,1H,H-2),4.76(d,J=11.5Hz,1H,PMB CH2),4.53(d,J=11.5Hz,1H,PMB CH2),4.21-4.14(m,2H,H-4,H-3),3.87-3.85(m,2H,H-5),3.79(s,3H,PMB CH3),0.89(s,9H,TBS),0.08(s,6H,TBS).

[0224] 13 C NMR(101MHz,CDCl3)δ166.63(Lev),159.39(Ar),133.53(Ar),129.81(Ar),129.73(Ar),129.28(Ar),1 29.22(Ar),128.47(Ar),113.91(Ar),104.15(C-1),85.89(C-4),84.60(C-2),76.87(C-3),68.73(PMB CH2),62.96(C-5),55.27(PMB CH3),25.91(TBS),18.39(TBS),-5.27(TBS).

[0225] HRMS(ESI)Calcd for C 26 H 40 NO7Si[M+NH4] + :506.2574,found:506.2576.

[0226] (7) Take a two-necked bottle, vacuum-bake it together with a stirring rod, and then introduce argon gas after cooling. Molecular sieves (1 g) were activated by burning with a blowtorch under vacuum conditions. After cooling to room temperature, the glycosyl donor compound 2-43 (100 mg, 151.33 μmol, 1.0eq), then TTBP (75.18 mg, 302.65 μmol, 2.0eq) was added, stirred at room temperature for 20 min, cooled to -78 ° C, AgOTf (93.31 mg, 363.18 μmol, 2.4eq) and p-TolSCl (74.60 μL, 19.21 μmol, 1.2eq) were added, and stirred at -78 ° C for 5 min. TLC detection showed that the glycosyl donor compound 2-43 completely disappeared, that is, the pre-activation was completed. The glycosyl acceptor compound 2-68 (66.55 mg, 136.19 μmol, 0.9eq) was dissolved in dry DCM (3 mL), and then slowly added dropwise to the reaction bottle. After stirring at -78 ° C for 20 min, the temperature was naturally raised to react for 3 h. TLC detection showed that the glycosyl donor compound 2-43 completely disappeared, that is, the pre-activation was completed. The glycosyl acceptor compound 2-68 (66.55 mg, 136.19 μmol, 0.9eq) was dissolved in dry DCM (3 mL), and then slowly added dropwise to the reaction bottle. After stirring at -78 ° C for 20 min, the temperature was naturally raised to react for 3 h. The reaction was completed when the glycosyl acceptor compound 2-68 disappeared. 0.2 mL of triethylamine was added to quench the reaction. The reaction solution was filtered through diatomaceous earth to remove the molecular sieves. The filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate was 40%) to obtain a light yellow oil, which was compound 2-69b (120 mg, 86%, p-Methoxybenzyl-2-O-benzoyl-3,4,6-O-tri-benzyl-β-D-galactopyranosyl-(1→3)-2-O-benzoyl-5-O-tert-butyldimethylsilyl-α-L-arabinofuranoside).

[0227] R f =0.55(toluene / acetonitrile,15:1). -25.6(c 0.36,CHCl3). 1<h2 style=";text-align:left;direction:ltr">H NMR(400MHz,CDCl3)δ8.08-8.03(m,2H,Ar),7.98-7.93(m,2H,Ar),7.53(dd,J =15.8,7.4Hz,2H,Ar),7.36(ddd,J=10.9,8.8,6.4Hz,8H,Ar),7.29(ddd,J=8. 2,6.2,3.2Hz,5H,Ar),7.23(t,J=3.7Hz,2H,Ar),7.19-7.12(m,4H,Ar),6.94( d,J=8.6Hz,2H,Ar),6.72(d,J=8.7Hz,2H,Ar),5.67(dd,J=10.0,8.1Hz,1H,gal H-2),5.16(s,1H),5.03-4.95(m,3H,gal H-1),4.62(d,J=11.9Hz,2H),4.49(d,J=12.4Hz,1H,PhCH2),4.39-4.29(m,4H),4. 26(d,J=12.2Hz,1H,PhCH2),4.12(dd,J=8.3,4.2Hz,1H),4.02(d,J=2.6Hz,1H,gal H-4),3.84-3.77(m,2H),3.75(s,3H),3.71(dd,J=10.1,2.8Hz,1H,gal H-3), 3.68-3.59(m,2H), 3.51(dd,J=7.6,3.8Hz,1H), 0.78(s,9H,TBS),-0.03(s,3H,TBS),-0.04(s,3H,TBS).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0228] <h2 style=";text-align:left;direction:ltr"> 13C NMR(101MHz,CDCl3)δ165.57(C=O),165.36(C=O),158.94(Ar),138.59(Ar),137.87(Ar),137.81(Ar ),133.30(Ar),132.62(Ar),130.51(Ar),129.90(Ar),129.82(Ar),129.57(Ar),129.54(Ar),129.30 (The),128.97(The),128.59(The),128.55(The),128.44(The),128.36(The),128.33(The),128.31(The),12 8.23(Ar),127.90(Ar),127.80(Ar),127.62(Ar),127.60(Ar),127.57(Ar),113.59(Ar),103.83(ara C-1),100.09(gal C-1),83.43,82.50,81.47,80.27(gal C-3),79.16,77.28,74.59,73.57,73.46,72.69(gal C-4),71.92(gal C-2),71.71,68.22,67.27,62.10,55.23,25.93(TBS),18.38(TBS),-5.25(TBS),-5.35(TBS).

[0229] HRMS(ESI)Calcd for C 60 H 72 NO 13 Si[M+NH4] + :1042.4773,found:1042.4788。

[0230] (8) Compound 2-69b (120 mg, 117.04 μmol, 1.0 eq) was dissolved in dichloromethane (9.5 mL) and water (0.5 mL) in an eggplant-shaped flask. DDQ (53.14 mg, 234.08 μmol, 2.0 eq) was added in batches and stirred at room temperature for 8 h. TLC monitoring showed that the reaction was complete. The reaction solution was filtered through celite, and the filtrate was diluted with dichloromethane (20 mL) and washed three times with saturated NaHCO3 solution and saturated NaCl solution in sequence. The organic phase was dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated to obtain a pale yellow oily crude product; The pale yellow oily crude product was dissolved in pyridine (10 mL), and acetic anhydride (22.13 μL, 234.08 μmol, 2.0 eq) and DMAP (1.43 mg, 11.70 μmol, 0.1 eq) were added in sequence under ice bath conditions. After the addition, the mixture was stirred at room temperature for 4 h. The reaction was monitored by TLC to be complete. The reaction solution was concentrated under reduced pressure to remove pyridine, and then diluted with dichloromethane (20 mL). The reaction solution was washed three times with 1 mol / L hydrochloric acid, saturated NaHCO3 solution and saturated NaCl solution in sequence. The organic phase was dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and purified by FL ASH rapid preparative chromatography (the mobile phase used was a petroleum ether-ethyl acetate mixture with a volume fraction of 30% ethyl acetate) to obtain a transparent oily liquid, namely compound 2-70 (72 mg, 76.02 μmol, 65%); the compound 2-70 was pumped with an oil pump for 1 h, then dissolved in dry dichloromethane (10 mL), p-methylthiophenol (11.33 mg, 91.22 μmol, 1.2 eq) was added, and SnCl4 (3.56 μL, 30.41 μmol, 0.4 eq) was added dropwise at 0°C. The reaction was stirred at 0°C for 25 min. The reaction was completed after monitoring by TLC, and triethylamine (0.1 mL) was added to quench the reaction. The reaction solution was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a petroleum ether-ethyl acetate mixture, and the volume fraction of the ethyl acetate was 60%) to obtain a yellow oil, which was compound 1-4 (36 mg, 53%, p-Tolyl-2-O-benzoyl-3,4,6-O-tri-benzyl-β-D-galactopyranosyl-(1→3)-2-O-benzoyl-L-arabinofuranoside).

[0231] R f =0.22(toluene / acetonitrile,15:1). -32.3 (c 0.91, CHCl3). 1H NMR(400MHz,CDCl3)δ8.16-8.08(m,2H),8.08-7.92(m,2H),7.65-7.53(m,2H),7.51-7.29(m,15H),7.29-7.18(m,6H),7.17-7.02(m,2H),5.86-5.74(m,1H),5.67-5.60(m,1H),5.57-5.50(m,1H),5.45-5.36(m,1H),5.06-5.00(m,1H),4.95-4.75(m,1H),4.65(m,2H),4.57-4.37(m,4H),4.26-4.06(m,1H),4.01-3.85(m,2H),3.79-3.51(m,4H),2.38-2.30(m,3H).

[0232] 13C NMR(101MHz,CDCl3)δ170.31(C=O),166.11(C=O),165.52(C=O),165.26(C=O),138.29(Ar),137.94(Ar),1 37.83(Ar),137.75(Ar),137.64(Ar),137.58(Ar),137.40(Ar),133.58(Ar),133.43(Ar),133.37(Ar),132 .86(Ar),132.68(Ar),132.11(Ar),132.05(Ar),130.62(Ar),130.52(Ar),130.34(Ar),130.17(Ar),130. 02(Ar),129.93(Ar),129.86(Ar),129.83(Ar),129.81(Ar),129.74(Ar),129.64(Ar),129.32(Ar),129.22 (Ar),128.59(Ar),128.53(Ar),128.50(Ar),128.41(Ar),128.38(Ar),128.35(Ar),128.29(Ar),128.14( Ar),128.06(Ar),127.98(Ar),127.96(Ar),127.80(Ar),127.73(Ar),101.09,97.06,91.44,90.66,82.81, 82.73,82.63,82.41,82.19,81.83,80.13,77.41,75.11,74.56,74.18,74.00,73.80,73.63,73.54,73.27,72.67,72.15,71.53,71.48,70.52,69.85,68.94,68.52,68.37,67.75,67.35,61.58,60.73,21.18,21.11.

[0233] HRMS(ESI)Calcd for C 53 H 56 NO 11 S[M+NH4] + :914.3574,found:914.3586.

[0234] Preparation example 4

[0235] To prepare compound 2-81, the reaction formula is as follows:

[0236] (1) Compound 2-21 (6.1 g, 9.13 mmol, 1.0 eq) was dissolved in 100 mL of dry dichloromethane. DMAP (786 mg, 5.48 mmol, 0.6 eq), levulinic acid (2.2 mL, 18.2 mmol, 2.0 eq) and DIC (3.17 mL, 17.3 mmol, 1.9 eq) were added in sequence under ice bath conditions. After addition, the mixture was reacted under ice bath conditions for 30 min and then stirred at room temperature for 1 h. TLC showed that the reaction was complete. Saturated NaHCO3 solution was added to quench the reaction and the mixture was diluted with dichloromethane. The reaction solution was washed three times with saturated NaHCO3 solution and saturated NaCl solution, dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and separated by column chromatography (the eluent used was petroleum ether: ethyl acetate: dichloromethane = 8:1:4 by volume) to give a white powder, namely compound 2-20 (5.8 g, 95.1%, p-Tolyl-2-O-benzoyl-3-O-benzyl-4-O-benzyl-6-levulinyl-1-thio-β-D-galactopyranoside).

[0237] R f =0.30(toluene / acetonitrile,20:1). +41.0(c 0.16,CHCl3); 1 H NMR (400MHz, CDCl3) δ8.02(d,J=7.2Hz,2H,Ar),7.59(t,J=7.4Hz,1H,Ar),7.46(t,J=7.7Hz,2H,Ar),7.39-7.27(m,7H,Ar),7.23-7. 11(m,5H,Ar),7.02(d,J=8.0Hz,2H,Ar),5.66(t,J=9.7Hz,1H,H-2),5.01(d,J=11.6Hz,1H,PhCH2),4.70(d,J=9.9Hz,1H,H-1),4.69 -4.61(m,2H,PhCH2),4.55(d,J=12.2Hz,1H,PhCH2),4.32(dd,J=11.1,6.8Hz,1H,H-6a),4.17(dd,J=11.2,5.8Hz,1H,H-6b),3.97(d ,J=2.0Hz,1H,H-4),3.74-3.63(m,1H,H-3H-5),2.76-2.70(m,2H,Lev),2.55-2.47(m,2H,Lev),2.29(s,3H,Lev),2.18(s,1H,tolyl CH3).

[0238] 13 C NMR(101MHz, CDCl3)δ206.53(C=O,Lev),172.43(C=O,Lev),165.25(C=O),138.19(Ar),137.73(Ar),137.47 (Ar),133.04(Ar),132.72(Ar),130.13(Ar),129.91(Ar),129.63(Ar),129.47(Ar),128.36(Ar),128.28(Ar ),128.21(Ar),127.80(Ar),127.78(Ar),127.65(Ar),87.12(C-1),81.11(C-3),76.07(C-5)74.22(PhC),72 .31(C-4),72.00(PhC),70.30(C-2),63.32(C-6),37.95(Lev),29.84(Lev),27.85(Lev),21.14(tolylCH3).

[0239] HRMS(ESI)Calcd for C 39 H 44 NO8S[M+NH4] + :686.2788,found:686.2791.

[0240] (2) Compound 2-46 (5 g, 8.41 mmol, 1.0 eq) was dissolved in 90 mL of dry THF and 10 mL of dry DMF. NapBr (3.7 g, 16.8 mmol, 2.0 eq) was added under ice bath conditions, and then a mineral oil solution of sodium hydride (500 mg, 12.6 mmol, 1.5 eq) (sodium hydride mass fraction 60%) was added in batches. The reaction was carried out at 0°C for 5 h. When TLC showed that the reaction was complete, a saturated NH4Cl solution was added to quench the reaction, and the mixture was extracted with dichloromethane. The organic phases were combined and dried over anhydrous Na2SO4. The reaction mixture was dried and filtered. The filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a mixture of petroleum ether and ethyl acetate, and the volume fraction of ethyl acetate was 25%) to obtain a white powder, namely compound 2-47 (5.6 g, 91%, p-Tolyl-2-O-benzoyl-3-O-tert-butyldimethylsilyl-4-O-benzyl-6-O-(2-naphthylmethyl)-1-thio-β-D-galactopyranoside).

[0241] R f =0.52(petroleum ether / ethyl acetate,4:1).<h2 style=";text-align:left;direction:ltr"> 1 <h2 style=";text-align:left;direction:ltr"> H NMR (400MHz,CDCl3)δ8.07-8.05(m,1H,Ar),8.05-8.03(m,1H,Ar),7.85-7.78(m,3H,Ar),7.73(s,1H,Ar),7.59-7.54(m,1H,Ar),7.51-7.39(m,5H,Ar),7.34(d,J=8.1Hz,2H,Ar),7.29-7 .23(m,5H,Ar),6.95(d,J=8.0Hz,2H,Ar),5.61(t,J=9.3Hz,1H,H-2),5.06(d,J=11.4Hz,1H,P hCH2),4.72(d,J=9.8Hz,1H,H-1),4.65(d,J=11.9Hz,1H,NapCH2),4.59(d,J=11.9Hz,1H,Nap CH2), 4.50(d,J=11.4Hz,1H,PhCH2), 3.96(d,J=8.6Hz,1H,H-3), 3.84(d,J=2.5Hz,1H,H-4), 3.80-3.66(m,3H,H-5H-6a H-6b), 2.24(s,3H,tolyl CH3), 0.76(s,9H,TBS), 0.09(s,3H,TBS), -0.11(s,3H,TBS).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0242] <h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> C NMR(100MHz,CDCl3)δ165.21(C=O),138.74(Ar),137.48(Ar),135.48(Ar),133.29(Ar),133.06(Ar),132.91(Ar), 132.50(Ar),130.45(Ar),129.96(Ar),129.84(Ar),129.47(Ar),128.30(Ar),128.23(Ar),128.16(Ar),127.94(Ar ),127.72(Ar),127.69(Ar),127.37(Ar),126.72(Ar),126.16(Ar),125.96(Ar),125.89(Ar),87.32(C-1),77.77( C-5),77.25(C-4),75.82(C-3)75.04(NapCH2),73.70(PhCH2),71.25(C-2),69.02(C-6),25.55(TBS),21.11(tolyl CH3),17.81(TBS),-4.05(TBS),-5.06(TBS).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0243] HRMS(ESI)Calcd for C 44 H 54 NO6SSi[M+NH4] + :752.3441,found:752.3443.

[0244] (3) Compound 2-47 (10 g, 13.6 mmol, 1.0 eq) was dissolved in 200 mL of anhydrous acetonitrile, and boron trifluoride etherate (3.36 mL, 27.2 mmol, 2.0 eq) was added dropwise in an ice bath. The mixture was reacted at 0°C for 5 min. TLC showed that the reaction was complete. 4 mL of triethylamine was added to quench the reaction, and the solvent was removed by concentration under reduced pressure. The residue was dissolved in 200 mL of dichloromethane and washed three times with water and saturated NaCl solution. The organic phases were combined, dried over anhydrous Na2SO4, and filtered. The filtrate was concentrated and separated by column chromatography (the eluent used was petroleum ether:ethyl acetate:dichloromethane = 4:1:4 by volume) to give a white powder, namely compound 2-48 (8.1 g, 96%, p-Tolyl-2-O-benzoyl-4-O-benzyl-6-O-(2-naphthylmethyl)-1-thio-β-D-galactopyranoside).

[0245] R f =0.14(petroleum ether / ethyl acetate,4:1). +31.9(c 0.14,CHCl3); 1H NMR(400MHz,CDCl3)δ8.05(d,J=7.4Hz,2H,Ar),7.85-7.77(m,3H,Ar),7.75(s,1H,Ar),7.54(t,J=7.4Hz,1H,Ar),7.45-7.48-7. (m,2H,Ar),7.42(dd,J=10.6,4.6Hz,3H,Ar),7.35(d,J=8.0Hz,2H,Ar),7.29-7.21(m,5H,Ar),6.98(d,J=8.0Hz,2H,Ar),5.2H,5 4(t,J=9.7Hz,1H,H-2),4.73(d,J=10.1Hz,2H,H-1,NapCH2),4.69-4.58(m,3H,2×PhCH2,NapCH2),3.95(d,J=3.2Hz,1H-4) ,3.81(dd,J=9.2,3.1Hz,1H,H-3),3.78-3.67(m,3H,H-5,H-6a,H-6b),2.61(d,J=9.2Hz,1H,OH),2.23(d,J=9.4Hz,3H,tolyl). CH3).

[0246] 13 C NMR(101MHz,CDCl3)δ166.68(Ar),138.19(Ar),137.99(Ar),135.29(Ar),133.33(Ar),133.12(Ar),133.04(A r),130.03(Ar),129.85(Ar),129.65(Ar),129.00(Ar),128.50(Ar),128.46(Ar),128.34(Ar),127.98(Ar),1 27.82(Ar),127.80(Ar),127.69(Ar),126.78(Ar),126.29(Ar),126.09(Ar),125.89(Ar),86.38(C-1),77.67 (C-5),76.80(C-4),75.34(NapCH2),74.45(C-3),73.73(PhCH2),72.38(C-2),68.59(C-6),21.21(tolylCH3).

[0247] HRMS(ESI)Calcd for C 38 H 40 NO6S[M+NH4] + :638.2576,found:638.2584。

[0248] (4) Take a two-necked bottle, vacuum-bake it together with a stirring rod, cool it to room temperature, and then introduce argon gas. Molecular sieves (15 g) were added, and the molecular sieves were activated by burner baking under vacuum conditions. After cooling to room temperature, argon was introduced into the reaction flask. Compound 2-45 (3 g, 5.06 mmol, 1.0 eq) and dry DCM (100 mL) were added sequentially, stirred at room temperature for 20 min, cooled to -78 ° C, stirred for 5 min, and then AgOTf (2.6 g, 10.12 mmol, 2.0 eq) and p-TolSCl (698.10 μL, 1.0 eq) were added sequentially. After stirring at -78 ° C for 5 min, TLC showed that the glycosyl donor compound 2-45 completely disappeared, indicating that the pre-activation was completed. The glycosyl acceptor compound 2-48 (3.14 g, 5.06 mmol, 1.0 eq) was dissolved in dry DCM (15 mL) and added dropwise to the reaction flask. After stirring at -78 ° C for 10 min, the temperature was naturally raised to react for 3 h. TLC showed that the glycosyl acceptor compound 2-48 was completely eliminated. The reaction was completed, and 3 mL of triethylamine was added to quench the reaction. The reaction solution was filtered through diatomaceous earth to remove the molecular sieves. The filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a mixture of petroleum ether-ethyl acetate-dichloromethane, the volume fraction of ethyl acetate was 30%, and the volume fraction of dichloromethane was 15%) to obtain a white powder, namely compound 2-48-2 (3.9 g, 71%, p-Tolyl-2-O-benzoyl-3-O-tert-butyldimethylsilyl-4,6-O-benzylidene-β-D-galactopyranosyl-(1-3)-2-O-benzoyl-4-O-benzyl-6-O-(2-naphthylmethyl)-1-thio-β-D-galactopyranoside).

[0249] R f =0.36(petroleum ether / ethyl acetate,2:1). +43.6(c 0.10,CHCl3); 1 H NMR (400MHz, CDCl3) δ7.80-7.72(m,5H,Ar),7.68(d,J=7.0Hz,3H,Ar),7.54-7.48(m,3H,Ar),7.46-7.39(m,3H,Ar),7.37- 7.24(m,10H,Ar),7.17(t,J=7.8Hz,2H,Ar),7.13-7.08(m,3H,Ar),6.88(d,J=8.0Hz,2H,Ar),5.58-5.47(m,3H,PhCHO2,H-2a ,H-2 b ),5.11(d,J=11.9Hz,1H,NapCH2),4.82(d,J=7.9Hz,1H,H-1 b ),4.71(d,J=9.9Hz,1H,H-1 a ),4.68(d,J=11.8Hz,1H,NapCH2),4.55(d,J=11.8Hz,1H,PhCH2),4.46(d,J=11.8Hz,1H,PhCH2),4.31(d,J=12.0Hz,1H,aH-6H2). a ),4.19(d,J=2.5Hz,1H,H-4 a ),4.14-4.06(m,2H,H-3 a ,H-5 b ),4.07-3.99(m,2H,H-4 b ,H-6b b ),3.85(dd,J=9.6,2.8Hz,1H,H-3 b ),3.74-3.65(m,2H,H-5 a ,H-6a a ),3.50(dd,J=12.1,7.9Hz,1H,H-6b a ),2.17(s,3H,tolyl CH3),0.66(s,9H,TBS),-0.07(s,3H,TBS),-0.26(s,3H,TBS).

[0250] 13 C NMR(101MHz,CDCl3)δ164.94(Ar),164.61(Ar),138.78(Ar),137.86(Ar),137.36(Ar),135.72(Ar), 133.33(The),133.04(The),132.79(The),132.40(The),132.11(The),130.52(The),130.04(The),130.01( Ar),129.74(Ar),129.64(Ar),129.52(Ar),128.81(Ar),128.25(Ar),128.16(Ar),127.98(Ar),127 .71(Ar),127.16(Ar),126.54(Ar),126.25(Ar),126.04(Ar),125.92(Ar),125.83(Ar),101.94(C-1 b),101.03(PhCHO2),87.64(C-1 a ),80.81(C-5 b ),78.31(C-5 a ),76.43(C-4 b ),75.78(C-4 a ),74.51(NapCH2),73.57(PhCH2),72.31(C-2 b ),71.94(C-3 b ),70.81(C-2 a ),69.70(C-6 a ),69.10(C-6 b ),25.42(TBS),21.06(tolyl CH3),17.85(TBS),-4.60(TBS),-4.84(TBS).

[0251] HRMS(ESI)Calcd for C 64 H 72 NO 12 SSi[M+NH4] + :1106.4544,found:1106.4563.

[0252] (5) Compound 2-48-2 (4 g, 3.67 mmol, 1.0 eq) was dissolved in 60 mL of DCM, 3 mL of H2O was added, and the mixture was stirred for 10 min under ice bath conditions. DDQ (1.67 g, 7.34 mmol, 2.0 eq) and β-pinene (1.17 mL, 7.34 mmol, 2.0 eq) were added in batches. The mixture was stirred for 10 min at 0 °C and then heated to room temperature for 12 h. TLC showed that the reaction was complete. 5 mL of saturated NaHCO3 solution was added to quench the reaction. The reaction solution was filtered through diatomaceous earth, and 100 mL of DCM was added to dilute the filtrate. The filtrate was washed three times with water and once with saturated sodium chloride solution. Anhydrous Na2SO4 was added to dry the mixture and filtered. The filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was stone). A mixture of oleyl ether-ethyl acetate-dichloromethane, wherein the volume fraction of ethyl acetate is 50% and the volume fraction of dichloromethane is 15%) to obtain a white powder, namely compound 2-22 (3.71 g, 78%, p-Tolyl-2-O-benzoyl-3-O-tert-butyldimethylsilyl-4,6-O-benzylidene-β-D-galactopyranosyl-(1→3)-2-O-benzoyl-4-O-benzyl-1-thio-β-D-galactopyranoside).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0253] <h2 style=";text-align:left;direction:ltr"> R<h2 style=";text-align:left;direction:ltr"> f <h2 style=";text-align:left;direction:ltr"> =0.18(petroleum ether / ethyl acetate,2:1).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr"> +12.0(c 0.15,CHCl3);<h2 style=";text-align:left;direction:ltr"> 1 <h2 style=";text-align:left;direction:ltr"> H NMR (400MHz, CDCl3) δ7.77-7.73(m, 2H, Ar), 7.70-7.66(m, 2H, Ar), 7.58-7.50(m, 3H, Ar), 7.45(t, J = 7.4Hz, 1H, Ar), 7.37(dt, J = 13.0, 4.7Hz, 4H, Ar), 7.31-7.26(m, 3H, Ar), 7.20(dt, J = 12.2, 6.7Hz, 7H, Ar), 6.98(d, J = 8.0Hz, 2H, Ar), 5.59-5.46(m, 3H, PhCHO2, H-2<h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> H-2<h2 style=";text-align:left;direction:ltr"> b <h2 style=";text-align:left;direction:ltr"> ),5.04(d,J=12.0Hz,1H,PhCH2),4.79(m,2H,H-1<h2 style=";text-align:left;direction:ltr"> b <h2 style=";text-align:left;direction:ltr"> ,PhCH2),4.68(d,J=10.0Hz,1H,H-1<h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> ),4.35(d,J=11.4Hz,1H,H-6a<h2 style=";text-align:left;direction:ltr"> b <h2 style=";text-align:left;direction:ltr"> ),4.15-4.02(m,4H,H-6b<h2 style=";text-align:left;direction:ltr"> b <h2 style=";text-align:left;direction:ltr"> H-3<h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> H-5<h2 style=";text-align:left;direction:ltr"> b <h2 style=";text-align:left;direction:ltr"> H-4<h2 style=";text-align:left;direction:ltr"> b <h2 style=";text-align:left;direction:ltr"> ),3.93-3.83(m,1H,H-3<h2 style=";text-align:left;direction:ltr"> b <h2 style=";text-align:left;direction:ltr"> ),3.72(dd,J=11.4,6.6Hz,1H,H-6a<h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> ),3.52-3.45(m,2H,H-4<h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> H-5<h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> ),3.40(dd,J=11.2,4.9Hz,1H,H-6b<h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> ),2.25(s,3H,tolyl CH3),0.67(s,9H,TBS),-0.05(s,3H,TBS),-0.25(s,3H,TBS).<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0254] <h2 style=";text-align:left;direction:ltr"> 13C NMR (101MHz, CDCl3) δ164.94(PhC=O), 164.53(PhC=O), 138.31(Ar), 137.71(Ar), 137. 60(Ar),132.78(Ar),132.40(Ar),132.24(Ar),130.14(Ar),129.98(Ar),129.94(Ar), 129.75(Ar),129.62(Ar),129.55(Ar),129.27(Ar),128.82(Ar),128.25(Ar),128.21( Ar),128.12(Ar),127.97(Ar),127.59(Ar),126.13(Ar),101.98(PhCHO2),101.01(C-1 b ),87.64(C-1 a ),80.66(C-5 b ),78.96(C-5 a ),76.43(C-4 b ),74.42(C-3 a ),74.04(PhC),72.30(C-2 b ),71.83(C-3 b ),70.79(C-2 a ),69.04(C-6 b ),66.82(C-4 a ),61.99(C-6 a ),25.35(TBS),21.07(tolyl CH3),17.81(TBS),-4.63(TBS),-4.89(TBS).

[0255] HRMS(ESI)Calcd for C 53 H 64 NO 12 SSi[M+NH4] + :966.3918,found:966.3947.

[0256] (6) Take a two-necked bottle, vacuum-bake it together with a stirring rod, and then introduce argon gas after cooling. Molecular sieves (6 g) were added, and the molecular sieves were activated by burning with a blowtorch under vacuum conditions. After cooling to room temperature, glycosyl donor compound 2-20 (200 mg, 299.04 μmol, 1.0 eq), TTBP (594.29 mg, 2.39 mmol, 8.0 eq) and dry DCM (30 mL) were added in sequence, and stirred at room temperature for 20 min. The mixture was cooled to -78 ° C, and AgOTf (153.67 mg, 598.09 μmol, 2.0 eq) and p-TolSCl (40.20 μL, 299.04 μmol, 1.0 eq) were added. The mixture was stirred at -78 ° C for 5 min. TLC detection showed that the glycosyl donor compound 2-20 disappeared completely, indicating that the pre-activation was completed. The glycosyl acceptor compound 2-21 (157.01 mg, 275.12 μmol, 0.92 eq) was dissolved in dry DCM (8 mL) and then added dropwise to the reaction flask. The mixture was stirred at -78 ° C for 10 min and then naturally heated to react for 1 h. TLC detection showed that the glycosyl acceptor compound 2-21 disappeared, indicating that the reaction was complete. The resulting reaction solution containing the disaccharide donor was quickly heated to room temperature and stirred for 20 min, then cooled to -78 ° C, and AgOTf (141.37 mg, 550.24 μmol, 1.84 eq) and p-TolSCl (36.99 μL, 275.12 μmol, 0.92 eq) were added. The mixture was stirred at -78 ° C for 5 min. TLC detection showed that the disaccharide donor completely disappeared. After pre-activation, the glycosyl acceptor compound 2-21 (145.06 mg, 254.19 μmol, 0.85 eq) was dissolved in dry DCM (8 mL) and added dropwise to the reaction flask. After stirring at -78 ° C for 10 min, the temperature was naturally raised to react for 1 h. TLC showed that the glycosyl acceptor compound 2-21 disappeared, indicating that the reaction was complete. The resulting reaction solution containing the trisaccharide donor was quickly heated to room temperature and stirred for 20 min, then cooled to -78 ° C, and AgOTf (130.62 mg, 508.37 μmol, 1.7 eq) and p-TolSCl (34.17 μL, 254.19 μmol, 0.85 eq) were added. After stirring at -78 ° C for 5 min, TLC showed that the trisaccharide donor completely disappeared. That is, the pre-activation is completed. The glycosyl acceptor compound 2-22 (219.95 mg, 230.26 μmol, 0.77 eq) was dissolved in dry DCM (8 mL) and added dropwise to the reaction flask. After stirring at -78 ° C for 10 min, the temperature was naturally raised to react for 3 h. TLC showed that the reaction was complete. The reaction solution containing the pentasaccharide donor was cooled to -78 ° C, and AgOTf (118.32 mg, 460.53 μmol, 1.54 eq) and p-TolSCl (31.76 μL, 230.26 μmol, 0.77 eq) were added. After stirring at -78 ° C for 5 min, TLC showed that the pentasaccharide donor completely disappeared, indicating that the pre-activation was completed. 1-Octanol (0.48 mL, 2.99 mmol, 10.0eq) was added dropwise to the reaction flask, stirred at -78 ° C for 10 min, and then naturally heated to react for 2 h. TLC showed that the reaction was complete, and 2 mL of triethylamine was added to quench the reaction. The reaction solution was filtered through celite, and the filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a mixture of petroleum ether-ethyl acetate-dichloromethane, the volume fraction of ethyl acetate was 60%, and the volume fraction of dichloromethane was 15%) to obtain a white foamy powder, namely compound 2-80 (452 ​​mg, 63%, Octyl-2-O-benzoyl-3,4-O-benzyl-5-levulinyl-β-D-galactopyranosyl-(1→6)- 2-O-benzoyl-3,4-O-benzyl-β-D-galactopyranosyl-(1→6)-2-O-benzoyl-3,4-O-benzyl-β-D-galactopyranosyl-(1→6)-[2-O-benzoyl-3-O- tert-butyldimethylsilyl-4,6-O-benzylene-β-D-galactopyranosyl]-(1→3)-2-O-benzoyl-4-O-benzyl-1-thio-β-D-galactopyranoside). .

[0257] R f =0.62(toluene / acetonitrile,6:1). +32.1(c 0.25,CHCl3); 1H NMR(600MHz,CDCl3)δ8.01(d,J=7.2Hz,2H,Ar),7.97(d,J=7.2Hz,2H,Ar),7.91-7.89(m,2H,Ar),7.67-7.62(m,4H,Ar),7.55-7.49(m,3H,Ar),7.49-7.45(m,3H,Ar),7.44-7.37(m,11H,Ar),7.35(dd,J=8.4,3.8Hz,3H,Ar),7.34-7.30(m,4H,Ar),7.30-7.25(m,7H,Ar),7.19-7.15(m,5H,Ar),7.12-7.08(m,5H,Ar),7.05(dd,J=16.2,8.2Hz,7H,Ar),7.00-6.97(m,2H,Ar),5.68(dd,J=10.0,8.0Hz,1H,H-2),5.53(dd,J=10.0,8.0Hz,1H,H-2),5.49(s,1H,PhCHO2),5.43(dd,J=9.9,7.9Hz,2H,H-2×2),5.33(dd,J=9.9,8.1Hz,1H,H-2),5.05(d,J=11.6Hz,1H,PhCH2),5.01(d,J=11.9Hz,1H,PhCH2),4.90(d,J=11.2Hz,1H,PhCH2),4.78(d,J=11.5Hz,1H,PhCH2),4.74-4.56(m,8H,H-1,PhCH2×7),4.49(d,J=7.9Hz,1H,H-1),4.39(d,J=12.3Hz,1H,PhCH2),4.37(d,J=7.9Hz,1H,H-1),4.30-4.20(m,6H,H-1,H-6×3,PhCH2×2),4.17-4.10(m,2H,H-1,H-6),4.07-3.97(m,5H,H-6×2,PhCH2),3.96-3.94(m,1H),3.91(s,1H),3.87(d,J=1.8Hz,2H),3.85(s,1H),3.77(dd,J=10.2,2.4Hz,1H),3.68(dd,J=10.2,2.5Hz,1H),3.65(t,J=6.5Hz,1H),3.60-3.56(m,2H,H-6×2),3.48-3.43(m,3H,H-6×2),3.43-3.39(m,2H),3.39-3.34(m,2H,linker),3.32-3.24(m,2H),2.94(ddd,J=9.8,7.7,5.5Hz,1H,linker),2.67-2.60(m,2H,Lev),2.43-2.37(m,2H,Lev),2.12(s,3H,Lev),1.12(dt,J=14.5,7.2Hz,3H,linker),1.03-0.96(m,3H,linker),0.89-0.84(m,4H,linker),0.79(t,J=7.3Hz,5H,linker),0.65(s,9H,TBS),-0.06(s,3H,TBS),-0.26(s,3H,TBS).

[0258] 13C NMR(151MHz,CDCl3)δ206.47(Lev),172.33(Lev),165.21(PhC=O),165.07 (PhC=O),165.03(PhC=O),164.69(PhC=O),164.12(PhC=O),138.53(Ar),1 38.43(Ar),138.40(Ar),138.04(Ar),137.77(Ar),137.56(Ar),137.56(Ar),137.32(Ar),134.36(Ar),133.21(Ar),133.01(Ar),132.66(Ar),132.66(Ar),132.32(Ar). 30(Ar),132.11(Ar),130.11(Ar),129.97(Ar),129.83(Ar),129.79(Ar),129.58(Ar),129.40(Ar),129.35(Ar),129.32(Ar),128.94(Ar),128.8(8). Ar),128.80(Ar),128.58(Ar),128.52(Ar),128.44(Ar),128.36(Ar),128.27(Ar),128.24(Ar),128.17(Ar),128.08(Ar),128.05(Ar),128.02(Ar) ,127.96(Ar),127.93(Ar),127.87(Ar),127.83(Ar),127.74(Ar),127.73(Ar),127.70(Ar),127.67(Ar),127.65(Ar),127.37(Ar),127.36(Ar),127.36(Ar),127.36(Ar). 7.27(Ar),127.20(Ar),127.02(Ar),127.00(Ar),126.20(Ar),102.12(C-1),101.50(C-1),101.35(C-1),101.12(C-1),101.00(PhCHO2),10.5(C0 -1),80.11,79.56,79.42,76.24,75.29,74.60(PhCH2),74.37(PhCH2),74.36(PhCH2),74.05(PhCH2),73.02,72.45,72.16,72.02,72.72,PhCH2. 1.79(C-2×2),71.77(C-2),71.73(C-2×2),71.42,71.14(PhCH2),70.90(PhCH2),69.47(C-6),68.89(linker),68.82(C-6),66.97(C-6),65.65.75(C-6),62.79(C-6), 37.75(Lev),31.56(linker),29.65(Lev),29.02(linker),28.85(linker),27.67(Lev),25.54 (linker),25.24(TBS),22.45(linker),17.67(TBS),13.95(linker),-4.78(TBS),-5.00(TBS).

[0259] MALDI-TOF MS Calcd for C 140 H 154 KO 33 S[M+K] + m / z:2429.9779,found:2429.8745.

[0260] (7) Compound 2-80 (1.0 g, 417.92 μmol, 1.0 eq) and THF (20 mL) were added to a polytetrafluoroethylene reaction bottle in sequence. The mixture was stirred for 10 min under ice bath conditions. 2 mL of hydrogen fluoride (5.0 eq) pyridine solution was added dropwise in batches. After the addition was complete, the mixture was stirred at 35 °C for 10 h. When TLC showed that the reaction was complete, 5 mL of triethylamine was added to quench the reaction. After the THF was removed by concentration under reduced pressure, 30 mL of 4-nitropropene was added. The concentrate was dissolved in DCM, washed three times with saturated NaHCO3 solution and saturated NaCl solution, dried over anhydrous Na2SO4, filtered, and the filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a mixture of petroleum ether-ethyl acetate-dichloromethane, the volume fraction of ethyl acetate was 70%, and the volume fraction of dichloromethane was 15%) to obtain a white foamy powder compound, namely compound 2-81 (820 mg, 86%, Octyl-2-O-benzoyl-3,4-O-benzyl-5-levulinyl-β-D-galactopyranosyl -(1→6)-2-O-benzoyl-3,4-O-benzyl-β-D-galactopyranosyl-(1→6)-2-O-benzoyl-3,4-O-benzyl-β-D-galactopyranosyl-(1→6) -[2-O-benzoyl-4,6-O-benzylene-β-D-galactopyranosyl]-(1→3)-2-O-benzoyl-4-O-benzyl-1-thio-β-D-galactopyranoside).

[0261] R f=0.19(toluene / acetonitrile,5:1). +24.5(c 0.35,CHCl3); 1H NMR(600MHz,CDCl3)δ8.01(dd,J=8.4,7.3Hz,2H,Ar),7.96(dd,J=7.2,6.0Hz,2H,Ar),7.91(dd,J=8.8,7.5Hz,2H,Ar),7.71-7.67(m,2H,Ar),7.66(dd,J=8.2,1.1Hz,2H,Ar),7.55-7.52(m,3H,Ar),7.48(t,J=7.4Hz,1H,Ar),7.43(dd,J=7.9,3.7Hz,3H,Ar),7.38(dd,J=8.6,7.4Hz,8H,Ar),7.33-7.28(m,10H,Ar),7.23-7.21(m,3H,Ar),7.18(ddd,J=12.1,6.8,4.5Hz,8H,Ar),7.11-7.05(m,12H,Ar),7.01-6.99(m,2H,Ar),5.66(dd,J=10.0,7.9Hz,1H,H-2),5.50-5.46(m,2H,PhCHO2,H-2),5.43(dd,J=10.0,7.9Hz,1H,H-2),5.37-5.30(m,2H,H-2×2),5.05(dd,J=11.7,5.4Hz,2H,PhCH2×2),4.88(d,J=11.2Hz,1H,PhCH2),4.78(d,J=11.4Hz,1H,PhCH2),4.74-4.65(m,6H,H-1,PhCH2×5),4.62(d,J=11.4Hz,1H,PhCH2),4.58(d,J=12.3Hz,1H,PhCH2),4.46(d,J=7.9Hz,1H,H-1),4.40(d,J=12.3Hz,1H,PhCH2),4.32(d,J=12.4Hz,1H,PhCH2),4.30-4.25(m,3H,H-1×2,H-6),4.23-4.20(m,2H,H-6×2),4.17(d,J=8.0Hz,1H,H-1),4.14-4.11(m,2H,PhCH2×2),4.09-4.05(m,1H,H-6),4.00-3.97(m,4H,H-6×2),3.93(d,J=2.3Hz,1H),3.88(d,J=2.3Hz,1H),3.79(dd,J=10.1,2.7Hz,1H),3.69(ddd,J=12.8,10.2,3.0Hz,2H),3.64(t,J=6.3Hz,1H),3.60-3.51(m,3H,H-6×3),3.46(s,1H),3.44-3.38(m,5H,H-6,linker),3.29(dd,J=9.9,1.9Hz,2H),3.00-2.95(m,1H,linker),2.68-2.65(m,2H,Lev),2.43-2.40(m,2H,Lev),2.14(s,3H,Lev),1.12(dt,J=14.5,7.3Hz,3H,linker),1.02-0.97(m,2H,linker),0.90-0.85(m,6H,linker),0.79(t,J=7.3Hz,4H,linker).

[0262] 13C NMR(151MHz,CDCl3)δ206.59(Lev),172.49(Lev),166.02(PhC=O),165.32 (PhC=O),165.25(PhC=O),165.19(PhC=O),164.42(PhC=O),138.70(Ar),1 38.60(Ar),138.17(Ar),137.73(Ar),137.72(Ar),137.52(Ar),137.47(Ar),133.35(Ar),133.12(Ar),132.84(Ar),132.57(Ar),132.52(Ar),132.52(Ar),132.52(Ar),132.52(Ar). 6(Ar),130.15(Ar),130.10(Ar),129.99(Ar),129.78(Ar),129.74(Ar),129.61(Ar),129.48(Ar),129.46(Ar),129.27(Ar),128.91(Ar),128.65(Ar). ),128.49(Ar),128.42(Ar),128.40(Ar),128.27(Ar),128.21(Ar),128.21(Ar),128.17(Ar),128.12(Ar),128.10(Ar),128.00(Ar),127.98(Ar),128.98(Ar),1 7.88(Ar),127.87(Ar),127.83(Ar),127.50(Ar),127.45(Ar),127.41(Ar),127.36(Ar),127.26(Ar),127.16(Ar),126.59(Ar),102.00(C-1),10.1. 84(C-1),101.59(PhCHO2),101.51(C-1),101.31(C-1),101.06(C-1),80.73,79.67,79.58,79.49,75.58,75.42,74.72(PhCHO2),75,75,75. 2(PhCH2),74.48(PhCH2),73.17,72.72(C-2),72.30,72.19,72.16,71.91(C-2×2,PhCH2),71.88(C-2),71.81(C-2),71.54,71,71.2,272(C-2),PhCH2. .07(PhCH2),69.57(C-6),69.11(linker),68.90(C-6),67.25(C-6),66.54,65.98(C-6),62.94(C-6),37.92(Lev),31.72(linker),29.81(Lev),29.18(linker),29.01(linker),27.81(Lev),25.69(linker),22.60(linker),14.08(linker).

[0263] MALDI-TOF MS Calcd for C 134 H 140 NaO 33 [M+Na] + m / z:2299.9175,found:2299.4739.

[0264] Example 1

[0265] (1) Compound 2-82 was prepared. The structural formula and English name of compound 2-82 are as follows:

[0266] Octyl-2-O-benzoyl-3,4-di-O-benzyl-6-O-levulinyl-β-D-galactopyranosyl-(1→6)-2-O-benzoyl-3,4-di-O-benzyl-β-D-galactopyranosyl-(1→6)-2 -O-benzoyl-3,4-di-O-benzyl-β-D-galactopyranosyl-{2-O-benzoyl-3,5-O-di-benzyl-α-L-arabinofuranosyl-(1→5)-2-O-benzoyl-3-O-benzyl-α-L- arabinofuranosyl-(1→5)-2-O-benzoyl-3-O-benzyl-α-L-arabinofuranosyl-(1→5)-[2-O-benzoyl-3,4,6-O-tri-benzyl-β-D-galactopyranosyl-(1→3) ]-2-O-benzoyl-α-L-arabinofuransyl-2-O-benzoyl-3,5-O-benzylidene-β-D-galactopyranosyl}-2-O-benzoyl-4-O-benzyl-β-D-galactopyranoside.

[0267] Take two bottles, vacuum bake the bottles together with the stirring rod, and then introduce argon gas after cooling. Molecular sieves (6 g) were activated by burning with a blowtorch under vacuum conditions. After cooling to room temperature, glycosyl donor compound 1-6 (300 mg, 554.86 μmol, 1.0 eq) was dissolved in dry DCM (20 mL) and added to the reaction flask. TTBP (1.38 g, 5.55 mmol, 10.0 eq) was then added and stirred at room temperature for 20 min. The mixture was cooled to -78 ° C. AgOTf (285.12 mg, 1.11 mol, 2.0 eq) and p-TolSCl (74.60 μL, 554.86 μmol, 1.0 eq) were added and stirred at -78 ° C for 5 min. TLC showed that the glycosyl donor compound 1-6 completely disappeared, i.e., the pre-activation was completed. The mixture was dried and precipitated. The glycosyl acceptor compound 1-7 (237.49 mg, 527.12 μmol, 0.95 eq) was dissolved in DCM (8 mL) and slowly added dropwise to the reaction flask. After stirring at -78 ° C for 20 min, TLC showed that the glycosyl acceptor 1-7 disappeared, indicating that the reaction was complete. The resulting reaction solution containing the disaccharide donor was quickly heated to room temperature and stirred for 20 min; then cooled to -78 ° C, AgOTf (270.87 mg, 1.05 mmol, 1.90 eq) and p-TolSCl (70.87 μL, 527.12 μmol, 0.95 eq) were added, and stirred at -78 ° C for 5 min. TLC showed that the disaccharide donor completely disappeared, indicating that the pre-activation was complete. The glycosyl acceptor compound 1-7 was dissolved in dry DCM (8 mL). The acceptor compound 1-7 (224.99 mg, 499.38 μmol, 0.9 eq) was added dropwise to the reaction flask and stirred at -78 ° C for 20 min. TLC showed that the glycosyl acceptor compound 1-7 disappeared, indicating that the reaction was complete. The resulting reaction solution containing the trisaccharide donor was quickly heated to room temperature and stirred for 20 min; then cooled to -78 ° C, AgOTf (256.61 mg, 998.75 μmol, 1.8 eq) and p-TolSCl (67.14 μL, 499.38 μmol, 0.9 eq) were added, and stirred at -78 ° C for 5 min. TLC showed that the trisaccharide donor completely disappeared, indicating that the pre-activation was complete. The glycosyl acceptor compound 1-4 (357 .79 mg, 460.54 μmol, 0.83 eq) was slowly added dropwise to the reaction flask, stirred at -78 ° C for 10 min and then naturally heated to react for 2 h. TLC showed that the glycosyl acceptor compound 1-4 disappeared, indicating that the reaction was complete. The resulting reaction solution containing the pentasaccharide donor was quickly heated to room temperature and stirred for 20 min; then cooled to -78 ° C, and AgOTf (236.65 mg, 921.07 μmol, 1.66 eq) and p-TolSCl (61.92 μL, 460.54 μmol, 0.83 eq) were added. Stirred at -78 ° C for 5 min. TLC showed that the pentasaccharide donor completely disappeared, indicating that the pre-activation was complete. The glycosyl acceptor compound 2-81 (1.The mixture was added dropwise to a reaction flask, stirred at -78°C for 10 minutes, and then naturally heated to react for 2 hours. TLC indicated the reaction was complete, and 2 mL of triethylamine was added to quench the reaction. The reaction solution was filtered through celite, and the filtrate was concentrated and separated by FLASH rapid preparative chromatography (the mobile phase used was a mixture of petroleum ether-ethyl acetate-dichloromethane, with a volume fraction of 40% ethyl acetate and a volume fraction of 15% dichloromethane) to obtain a white foamy powder, namely compound 2-82 (1.21 g, 64%).

[0268] R f =0.55(toluene / acetonitrile,6:1). -3.3 (c 0.60, CHCl3); 1<h2 style=";text-align:left;direction:ltr">H NMR (600MHz,CDCl3)δ8.03-8.00(m,7H,Ar),7.98-7.93(m,5H,Ar),7.88(d,J=7.2Hz,2H,Ar),7.85-7.83(m,2H,Ar),7.57-7.48(m,14H,Ar),7.44-7.37(m,18H,Ar),7.34(dd,J=14.4,7.4Hz,5H,Ar) 7.31-7.26(m,4H,Ar),7.24-7.21(m,16H,Ar),7.21-7.16(m,23H,Ar),7.16-7.13(m,7H,Ar),7.10-7.06(m,13H,Ar),7.05-7.01(m,5H,Ar),6.98-6.93(m,4H,Ar),5.67(dd,J=10.0,7.9Hz,1H,gal H-2), 5.55-5.51(m,2H,gal IH-2×2), 5.49(s,1H,PhCHO2), 5.43-5.37(m,3H,ara H-2,gal H-2×2), 5.34(s,2H,ara H-2×2), 5.29(dd,J=9.9,8.2Hz,1H,gal H-2), 5.23(s,1H,ara H-1), 5.23(s,1H,ara H-1), 5.11(d,J=3.0Hz,1H,ara H-2), 5.07-5.02(m,3H,ara H-1×2,PhCH2),4.98(d,J=12.0Hz,1H,PhCH2),4.89(d,J=11.2Hz,1H,PhCH2),4.83(d,J=11.7Hz,1H,PhCH2),4.76(d,J=11.4Hz ,1H,PhCH2),4.73(d,J=11.5Hz,1H,PhCH2),4.71(d,J=11.4Hz,1H,PhCH2),4.69(d,J=11.5Hz,1H,PhCH2),4.66-4.62(m,4H,gal H-1,PhCH2×3),4.60(d,J=7.6Hz,1H,PhCH2),4.56(dd,J=10.1,4.8Hz,3H,gal H-1,PhCH2×2),4.53(d,J=11.6Hz,1H,PhCH2),4.51-4.48(m,4H,gal H-1,PhCH2×3),4.44(dd,J=12.1,3.5Hz,2H,PhCH2×2),4.40-4.34(m,5H,gal H-1×2,PhCH2×3),4.28(d,J=11.7Hz,1H,PhCH2),4.26-4.21(m,5H,gal H-6×2,PhCH2),4.18(dd,J=11.7,7.3Hz,3H,PhCH2×2),4.13(dd,J=9.5,5.4Hz,5H,gal H-6),4.10-4.08(m,3H,gal H-1,gal H-6),4.02(dd,J=11.0,5.3Hz,2H,ara H-5,PhCH2),3.99(s,1H),3.96(d,J=2.1Hz,1H),3.92-3.88(m,3H,ara H-5,gal H-6),3.85(d,J=5.2Hz,3H),3.84-3.79(m,2H,araH-5×2),3.74(dd,J=10.4,3.1Hz,1H),3.69-3.62(m,5H,ara H-5×2),3.56(ddd,J=14.3,10.2,4.1Hz,4H,ara H-5,gal H-6×3),3.50-3.46(m,6H,ara H-5,gal H-6×2),3.43-3.36(m,4H,gal H-6×2),3.33-3.25(m,3H,linker),3.15(s,1H),2.92-2.83(m,1H,linker),2.68-2.61(m,2H,Lev),2.44-2.38(m,2H,Lev),2.13(s,3H,Lev),1.16-1.05(m,3H,linker),1.05-0.94(m,3H,linker),0.90-0.81(m,5H,linker),0.78(t,J=7.3Hz,4H,linker).

[0269] 13C NMR(151MHz,CDCl3)δ206.65(Lev),172.52(Lev),165.34(C=O),165.31(C=O),165.31(C=O),165.30(C=O),165.27(C=O),165.20(C=O), 164.68(C=O),164.50(C=O),164.22(C=O),138.65(Ar),138.61(Ar),138.49(Ar),138.43(Ar),138.24(Ar),138.01(Ar),137.94(Ar),1 37.90(On),137.85(On),137.80(On),137.76(On),137.75(On),137.73(On),137.66(On),137.52(On),133.39(On),133.16(On),132.7 7(On),132.74(On),132.31(On),131.84(On),130.30(On),130.14(On),130.07(On),130.01(On),129.98(On),129.86(On),129.83(On) ,129.79(On),129.77(On),129.74(On),129.63(On),129.56(On),129.52(On),129.47(On),129.46(On),129.37(On),129.30(On),129 .16(On),128.66(On),128.56(On),128.53(On),128.49(On),128.45(On),128.43(On),128.40(On),128.37(On),128.36(On),128.33(A r),128.29(On),128.25(On),128.21(On),128.18(On),128.12(On),128.08(On),128.04(On),127.98(On),127.92(On),127.90(On),1 27.86(On),127.79(On),127.69(On),127.68(On),127.67(On),127.65(On),127.57(On),127.54(On),127.50(On),127.47(On),127.41 (On),127.32(On),127.18(On),126.24(On),106.95(C-1),106.26(C-1),106.21(C-1),105.95(C-1),102.58(C-1),101.51(C-1),101.50(C-1),101.32(C-1),101.28(C-1),100.69(PhCHO2),100.43(C-1),83.49,83.28,82.78(araC-2),82.43,82.14,82.05,81.88(ara C-2),81.76(ara C-2×2),81.65,80.31,80.24,79.82,79.71,79.67,79.54,76.32,75.89,75.40,74.91(PhCH2),74.81(PhCH2),74.55(PhCH2),74.52(PhCH2),74.44(PhCH2),74.10(PhCH2),73.48(PhCH2),73.44(PhCH2),73.33(PhCH2),73.12,72.52(PhCH2),72.45(PhCH2),72.39(PhCH2),72.37(PhCH2),72.30(PhCH2),72.14(PhCH2),72.01(PhCH2),71.97(PhCH2),71.94(gal C-2),71.90(gal C-2),71.87(gal C-2),71.65(gal C-2),71.56(gal C-2),71.35(PhCH2),71.23(PhCH2),71.05(PhCH2),70.76(gal C-2),69.54(gal C-6),69.26(gal C-6),68.89(linker),68.68(gal C-6),68.19(gal C-6),66.77(gal C-6),66.71,65.97(ara C-5),65.65(ara C-5),65.53(ara C-5),65.31(ara C-5),63.06(gal C-6),60.43,37.94(Lev),31.74(linker),29.83(Lev),29.20(linker),29.19(linker),29.02(linker),27.85(Lev),25.70(linker),22.62(linker),14.11(linker).

[0270] MALDI-TOF MS Calcd for C 244 H 244 NaO 59 [M+Na]+ m / z:4140.5990,found:4140.7446.

[0271] (2) Compound 2-34 was prepared. The structural formula and English name of compound 2-34 are as follows:

[0272] Octylβ-D-galactopyranosyl-(1→6)-β-D-galactopyranosyl-(1→6)-β-D-galactopyranosyl-(1→6)-{α-L-arabinofuranosyl-(1→5)-α-L-arabinofuranosyl-( 1→5)-α-L-arabinofuransyl-(1→5)-[β-D-galactopyranosyl-(1→3)]-α-L-arabinofuransyl-(1→3)-β-D-galactopyranosyl-(1→3)}-β-D-galactopyranoside.

[0273] Compound 2-82 (142 mg, 34.46 μmol, 1.0 eq) was dissolved in dichloromethane (10 mL) and methanol (5 mL), and then a methanol solution of sodium methoxide (30 wt%) was added dropwise to adjust the pH value to 9-10. The reaction was allowed to proceed for 9 h at room temperature. After TLC monitoring, the reaction was completed. A cation exchange resin was added to neutralize the mixture until the pH value reached 7. The cation exchange resin was removed by filtration, and the filtrate was concentrated and separated by polystyrene gel exclusion chromatography (ethyl acetate as the eluent) to obtain the benzoyl-free product. Crude product; The debenzoylated crude product was dissolved in a solvent (ethyl acetate: methanol: water = 3 mL: 6 mL: 3 mL), 10% Pd / C (200 mg) was added, and the reaction was carried out at room temperature and 0.4 MPa hydrogen conditions for 18 hours. The reaction solution was filtered through a microporous filter to remove Pd / C, and the filtrate was concentrated and separated by size exclusion chromatography on Sephadex LH-20 (by volume ratio, the eluent used was methanol: water = 1: 1) to give a white glassy product, namely compound 2-34 (41 mg, 73%).

[0274] 1H NMR(600MHz,D2O)δ5.27(s,1H,ara H-1),5.08(s,2H,ara H-1×2),5.08(d,J=1.1Hz,1H,ara H-1),4.66(d,J=7.5Hz,1H,gal H-1),4.53(d,J=7.9Hz,1H,gal H-1),4.46(dt,J=12.3,8.2Hz,4H,gal H-1×4),4.41-4.38(m,2H),4.23-4.18(m,4H),4.13-4.11(m,3H),4.10-4.07(m,2H),4.05-4.02(m,2H,gal H-6×2),4.00(dt,J=5.6,2.7Hz,3H),3.96-3.86(m,15H,araH-5×2,gal H-6×3),3.84-3.74(m,12H,ara H-5×6,gal H-6,linker),3.73-3.68(m,8H,ara H-5×2),3.68-3.63(m,4H),3.53(dd,J=17.2,7.8Hz,4H),1.65-1.59(m,2H,linker),1.31-1.24(m,10H,linker),0.87-0.84(m,3H,linker).

[0275] 13C NMR(151MHz,D2O)δ110.09(ara C-1),108.25(ara C-1),108.21(ara C-1),108.15(ara C-1),104.90(gal C-1),104.15(gal C-1×2),103.93(gal C-1),103.45(gal C-1),103.07(gal C-1),85.20,84.70,83.14,83.08,83.03,82.80,81.65,81.55,81.48,80.47,80.32,77.47,77 .41,77.25,75.97,75.88,75.68,74.48,74.45,74.11,73.48,73.33,73.30,73.24,71.48(gal C-6),71.43,70.92,70.53,70.08(gal C-6),69.96(gal C-6),69.77(gal C-6),69.35,69.25,69.20,67.58(gal C-6),67.50(gal C-6),67.38(ara C-5),61.91(ara C-5),61.75(ara C-5),61.68(araC-5),61.58(linker),31.86(linker),29.50(linker),29.25(linker),29.16(linker),25.82(linker),22.79(linker),14.20(linker).

[0276] HRMS(ESI)Calcd for C 63 H 107 O 46 [MH] - :1629.6139; found:1629.6140.

[0277] Test Example 1 Biological Activity Evaluation

[0278] 1. Cell culture conditions

[0279] The three pancreatic cancer cell lines Aspc-1, Bxpc-3, and Panc-1, as well as the hepatocyte LO2 cells used in this experiment, were provided by Peking University People's Hospital and the Institute of Materia Medica, Chinese Academy of Medical Sciences. Aspc-1 and Bxpc-3 cells were cultured in RPMI 1640 medium (Gibco, Thermo Fisher Scientific, USA) supplemented with 10% fetal bovine serum (HyClone, Thermo Fisher Scientific, USA) and 1% penicillin / streptomycin (Life Technologies, Thermo Fisher Scientific, USA); Panc-1 and LO2 cells were cultured in DMEM medium (Gibco, Thermo Fisher Scientific, USA) supplemented with 10% fetal bovine serum (HyClone, Thermo Fisher Scientific, USA) and 1% penicillin / streptomycin (Life Technologies, Thermo Fisher Scientific, USA). Cell cultures were maintained at 37°C with a constant humidity and 5% CO2.

[0280] 2. Cell recovery

[0281] Remove the cell cryovial from the liquid nitrogen tank and quickly thaw it in a constant temperature water bath preheated to 37°C. Centrifuge at 1000 rpm for 5 minutes, discard the supernatant, and transfer the tube to complete culture medium containing preheated RPMI 1640 or DMEM. Mix the culture medium and cell suspension evenly and place the tube in an incubator for culture.

[0282] 3. Cell subculture

[0283] When the cells adhere to the wall and divide and grow to 80-90%, they are subcultured. Specifically, the original culture medium in the culture dish is poured out, and the cells are washed twice with sterile PBS with a pH value of 7.4. Then, trypsin is added and digested at room temperature for about 2 minutes. After most of the cells fall off, an equal volume of complete culture medium is added to stop the digestion, and the adherent cells are gently blown until all are detached. After centrifugation at 1000 rpm for 5 minutes, the supernatant is discarded, and the cells are resuspended with complete culture medium and subcultured at a ratio of 1:3.

[0284] 4. Evaluate the inhibitory effect of the compound on pancreatic cancer cell proliferation at 50 μM

[0285] Three pancreatic cancer cells, Aspc-1, Bxpc-3, and Panc-1, were seeded in 96-well plates at a cell density of 5×10 3cells / well (100 μL), after the cells adhered, gemcitabine (50 μM), compound 2-11 (140-mer 2-11, 50 μM), 2-30 (70-mer2-30, 50 μM), 2-31 (40-mer 2-31, 50 μM), 2-32 (30-mer 2-32, 50 μM), 2-33 (10-merA2-33, 50 μM), 2-34 (10-mer B 2-34, 50 μM), 2-35 (5-merA2-35, 50 μM), 2-36 (5-mer B 2-36, 50 μM) and 2-37 (5-mer C 2-37, 50 μM) were added, and the cells were incubated for 72 h. 10 μL was added to each well. The CCK-8 reagent was incubated at 37°C for 2 h, and after shaking evenly, the absorbance at 450 nm was measured in a microplate reader. The cell survival rate was calculated according to the following formula: Cell survival rate (%) = (OD sample - OD blank) / (OD control - OD blank) × 100%;

[0286] The structural formulas of compounds 2-11, 2-30, 2-31, 2-32, 2-33, 2-34, 2-35, 2-36 and 2-37 are shown below:

[0287] 5. Evaluation of the inhibitory effect of compound 2-34 on pancreatic cancer cell proliferation at different concentrations

[0288] Three pancreatic cancer cells, Aspc-1, Bxpc-3, and Panc-1, were seeded in 96-well plates at a cell density of 5×10 3 cells / well (100 μL). After the cells adhered, different concentrations of compound 2-34 (3.125 μM, 6.25 μM, 12.5 μM, 25 μM, 50 μM, and 100 μM) were added and incubated for 72 h. 10 μL of CCK-8 reagent was added to each well and incubated at 37°C for 2 h. After shaking evenly, the absorbance at 450 nm was measured in a microplate reader to calculate the cell survival rate.

[0289] 6. Evaluation of the cytotoxicity of compound 2-34 on hepatocyte LO2 cells at different concentrations

[0290] Hepatocytes LO2 were seeded in 96-well plates at a cell density of 5×10 3cells / well (100 μL). After the cells adhered, different concentrations of compound 2-34 (3.125 μM, 6.25 μM, 12.5 μM, 25 μM, 50 μM, 100 μM) and the positive drug gemcitabine (3.125 μM, 6.25 μM, 12.5 μM, 25 μM, 50 μM, 100 μM) were added and incubated for 72 h. 10 μL of CCK-8 reagent was added to each well and incubated at 37 ° C for 2 h. After shaking evenly, the absorbance at 450 nm was measured in a microplate reader to calculate the cell survival rate.

[0291] 7. Evaluation of the effect of compound 2-34 on apoptosis of pancreatic cancer cells Panc-1 at different concentrations

[0292] Pancreatic cancer cells Panc-1 were seeded in 24-well plates at a cell density of 3×10 4 After cells adhered to the wall, different concentrations of compound 2-34 (25 μM, 50 μM, 100 μM) were added and incubated for 72 h. All cells were collected, washed twice with PBS, and resuspended in binding buffer (Beyotime, Shanghai, China). 5 μL Annexin V-FITC and 10 μL PI dye were added in sequence and stained in the dark for 20 min. The apoptotic cell ratio was detected using a flow cytometer (Beckman cytoflex), and the specific apoptotic ratio was analyzed using Cytoflex software.

[0293] 8. Evaluate the effect of compound 2-34 on the cell cycle of pancreatic cancer cells Panc-1 at different concentrations

[0294] Pancreatic cancer cells Panc-1 were seeded in 24-well plates at a cell density of 6×10 4 cells / well. After the cells adhered, different concentrations of compound 2-34 (25 μM, 50 μM, 100 μM) were added and incubated for 72 h. All cells were collected, washed twice with PBS, fixed with 70% ethanol and allowed to stand overnight. The cells were collected and washed twice with PBS, and PI staining containing RNase was added and stained in the dark for 30 min. The nucleic acid content in the cells was detected by flow cytometry, and the cell proportion in each cycle was analyzed using ModiFit software.

[0295] 9. Test results

[0296] The intact heptaglycoside (140-mer 2-11) and its fragments (70-mer 2-30, 40-mer 2-31, 30-mer 2-32, 10-merA2-33, 10-merB 2-34, 5-merA2-35, 5-mer B 2-36, 5-mer C 2-37) were evaluated in vitro for their anti-pancreatic cancer activity, where the three pancreatic cancer cells were Aspc-1, Bxpc-3, and Panc-1. First, the inhibitory effect of each glycan molecule on the proliferation of three pancreatic cancer cell lines was evaluated at a concentration of 50 μM. The three pancreatic cancer cells were co-incubated with the drug for 72 hours, and then the CCK-8 method was used to detect the specific cell survival. The experimental results showed (Figure 2a) that at a concentration of 50 μM, the complete 37 glycan molecule and most 37 glycan fragments had almost no significant inhibitory effect on the proliferation of the three pancreatic cancer cells, while compound 2-34 had better activity (the inhibition rate against Aspc-1 reached 74.9%, the inhibition rate against Bxpc-3 reached 29.5%, and the inhibition rate against Panc-1 reached 72.1%). It is worth mentioning that the inhibition rate of compound 2-34 against Aspc-1 and Panc-1 cells has exceeded the effect of gemcitabine, a first-line anti-pancreatic cancer drug in the clinic (gemcitabine inhibition rate against Aspc-1 reached 61.4% and Panc-1 inhibition rate reached 23.2%). In addition, for the three pancreatic cancer cell lines, compound 2-34 showed a significant concentration-dependent inhibition of their proliferation (Figure 2b). To further verify the safety of compound 2-34, its cytotoxicity against normal human liver cells LO2 was tested. The experimental results showed that compound 2-34 had no cytotoxicity against the growth of liver cells LO2 at a concentration of 100 μM, demonstrating a superior safety profile compared to the active drug gemcitabine (Figure 2, c).

[0297] Since Panc-1 cells have a certain resistance to gemcitabine, but are more sensitive to compound 2-34, the present application further explores how compound 2-34 works on Panc-1 cells (Figure 3). The present application co-incubated Panc-1 cells with three different concentration gradients of compound 2-34 (25μM, 50μM, 100μM) for 72h, and explored the effect of compound 2-34 on cell apoptosis by Annexin V-FITC / PI double staining combined with flow cytometry analysis technology. The results showed that as the dosage concentration increased, the proportion of cell apoptosis showed an increasing trend. The apoptosis rate of the blank group was 16.7%, the apoptosis rate of the 25μM group was 31.99%, the apoptosis rate of the 50μM group was 31.92%, and the apoptosis rate of the 100μM group was 67.59%. The experimental results show that compound 2-34 inhibits the proliferation of tumor cells by promoting cell apoptosis. In order to further explore how compound 2-34 promotes the process of cell apoptosis, this application starts from the cell cycle, and incubates Panc-1 cells with three different concentrations of compound 2-34 (25μM, 50μM, 100μM) for 72h, and explores the effect of compound 2-34 on the cell cycle by flow cytometry. The results show that with the increase of the dosage concentration, the proportion of cells in each period changes significantly. Among them, the proportion of G1 phase cells decreased from 58.43% (blank group) to 51.33% (25μM), 46.99% (50μM) and 42.43% (100μM), while the proportion of S phase cells increased from 15.17% (blank group) to 22.19% (25μM), 27.66% (50μM) and 36.29% (100μM). The number of cells in the G2 period is relatively stable and changes little. The results of the cell cycle experiment show that compound 2-34 can block Panc-1 cells in the S phase. Therefore, it is speculated that the mechanism of action of compound 2-34 is mainly to promote tumor cell apoptosis by blocking the cell cycle at the S phase, thereby exerting anti-tumor efficacy.

[0298] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A polysaccharide having a structure shown in Formula I: In formula I, n1=0-6, n2=0-2, n3=0-3, and R is a C1-C10 alkoxy group.

2. The polysaccharide according to claim 1, characterized in that The n1=1-5.

3. The polysaccharide according to claim 2, characterized in that The n1=2-4.

4. The polysaccharide according to claim 1, characterized in that The n2=0~1.

5. The polysaccharide according to claim 1, characterized in that The n3=1~3.

6. The polysaccharide according to claim 5, characterized in that The n3=2~3.

7. The polysaccharide according to claim 1, characterized in that The R is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy or decyloxy.

8. The polysaccharide according to claim 7, characterized in that The R is a C5-C10 alkoxy group.

9. The polysaccharide according to claim 8, characterized in that The R is a straight chain alkoxy group.

10. The polysaccharide according to any one of claims 1 to 9, characterized in that The n1=3, n2=0, n3=3, and R is n-octyloxy.

11. The method for preparing the polysaccharide according to any one of claims 1 to 10, comprising the following steps: Compound 1-3, silver trifluoromethanesulfonate, p-methylbenzenesulfonyl chloride and an organic solvent are mixed to perform a first activation reaction to obtain a first activation product system; The first activated product system is mixed with compound 1-4 to perform a first glycosylation coupling reaction to obtain a first coupling product system; The first coupling product system, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride are mixed to perform a second activation reaction to obtain a second activated product system; The second activated product system is mixed with compound 1-5, and a second glycosylation coupling reaction is performed to obtain compound 1-2; The compound 1-2 is subjected to a debenzoylation reaction and a debenzylation-debenzylation reaction in sequence to obtain a polysaccharide having a structure shown in Formula I; The structural formulas of Compound 1-3, Compound 1-4, Compound 1-5 and Compound 1-2 are shown below: The n1, n2, n3 and R are defined as in Formula I.

12. The preparation method according to claim 11, characterized in that: In the reaction raw materials of the first activation reaction, the molar ratio of the compound 1-3, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride is 1:(1.2-5):

1.

13. The preparation method according to claim 11 or 12, characterized in that: The temperature of the first activation reaction is -60 to -78°C, and the time is 2 to 10 minutes.

14. The preparation method according to claim 11, characterized in that: In the reaction raw materials of the first glycosylation coupling reaction, the molar ratio of the compound 1-3 to the compound 1-4 is 1:(0.85-0.92).

15. The preparation method according to claim 11 or 14, characterized in that: The first glycosylation coupling reaction includes sequentially performing a first stage reaction and a second stage reaction; the temperature of the first stage reaction is -60 to -78°C, and the time is 5 to 15 minutes; after the first stage reaction, the temperature is naturally raised from the temperature of the first stage reaction to perform a second stage reaction, and the time of the second stage reaction is 1.5 to 2.5 hours.

16. The preparation method according to claim 11, characterized in that: In the reaction raw materials of the second activation reaction, the molar ratio of the compound 1-4, silver trifluoromethanesulfonate and p-methylphenylsulfonyl chloride is 1:(1.2-5):

1.

17. The preparation method according to claim 11 or 16, characterized in that: The temperature of the second activation reaction is -60 to -78°C, and the time is 2 to 10 minutes.

18. The preparation method according to claim 11, characterized in that: In the reaction raw materials of the second glycosylation coupling reaction, the molar ratio of the compound 1-4 to the compound 1-5 is (0.8-0.85):(1-2).

19. The preparation method according to claim 11 or 18, characterized in that: The second glycosylation coupling reaction includes sequentially performing a first stage reaction and a second stage reaction; the temperature of the first stage reaction is -60 to -78°C, and the time is 5 to 15 minutes; after the first stage reaction, the temperature is naturally raised from the temperature of the first stage reaction to perform a second stage reaction, and the time of the second stage reaction is 1.5 to 2.5 hours.

20. The preparation method according to claim 11, characterized in that: The step of sequentially subjecting compound 1-2 to a debenzoylation reaction and a debenzylation-debenzylidene reaction comprises: Mixing compound 1-2 with an organic solvent, and performing a debenzoylation reaction under alkaline conditions to obtain a debenzoylation compound; The debenzoyl compound, palladium-carbon catalyst, organic solvent and water are mixed to carry out debenzylation-debenzylidene reaction in a hydrogen atmosphere.

21. The preparation method according to claim 20, characterized in that: The alkaline condition refers to a pH value of 9 to 10; the alkaline reagent providing the alkaline condition is a methanol solution of sodium methoxide.

22. The preparation method according to claim 20 or 21, characterized in that: The temperature of the debenzoylation reaction is 10 to 30° C. and the time is 5 to 24 hours.

23. The preparation method according to claim 20, characterized in that: The temperature of the debenzylation-debenzylation reaction is 10-30° C., the hydrogen pressure is 0.3-10 MPa, and the time is 5-24 hours.

24. Use of the polysaccharide according to any one of claims 1 to 10 in the preparation of anti-tumor drugs.

25. The use according to claim 24, characterized in that The tumor is pancreatic cancer, gastric cancer, liver cancer or cervical cancer.

26. The use according to claim 24 or 25, characterized in that The anti-tumor drug comprises the polysaccharide and a pharmaceutically acceptable carrier, and the mass fraction of the polysaccharide in the anti-tumor drug is 0.1-99.9%.

27. The use according to claim 26, characterized in that The dosage form of the anti-tumor drug includes injection or oral tablet.

28. The use according to claim 27, characterized in that The anti-tumor drug is administered orally, intravenously or subcutaneously.

29. An anti-tumor drug comprising the polysaccharide according to any one of claims 1 to 10 and a pharmaceutically acceptable carrier.

30. The anti-tumor drug according to claim 29, characterized in that: The mass fraction of the polysaccharide in the anti-tumor drug is 0.1-99.9%.

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