Preparation of angelica polysaccharide APS-1 II 13 sugar and substructure 9 sugar with anti-leukemia activity

Abstract

The invention provides a method for constructing a 1, 2-cis fucose glycosidic bond with high stereoselectivity and application of the method to preparation of a 13 sugar repeating unit and a substructure 9 sugar of angelica polysaccharide APS-1II and evaluation of anti-leukemia activity of the 13 sugar and the 9 sugar, and belongs to the technical field of polysaccharide preparation. The accelerant composition for realizing the high-stereoselectivity 1, 2-cis-fucose glycosylation reaction comprises trimethylsilyl iodide (TMSI) and triphenylphosphine oxide (Ph3PO), and fucosyl N-phenyl trifluoroacetyl imine ester (PTFAI) of which the O-3 position and / or the O-4 position are / is substituted by acyl is used as a donor. The 13 sugar repeating unit of the angelica polysaccharide APS-1II and the substructure 9 sugar thereof provided by the invention have a remarkable inhibition effect on the activity of human leukemia K562 cells and mouse leukemia L1210 cells.

Description

Technical Field

[0001] The invention belongs to the technical field of polysaccharide preparation, and specifically relates to a method for a highly stereoselective 1,2-cis-fucosylation reaction and an application thereof in the preparation of 13-sugar repeating units and substructure 9-sugar of angelica polysaccharide APS-1 II with anti-leukemia activity. Background Art

[0002] Angelica sinensis is a traditional Chinese medicine with miraculous effects on female gynecological diseases. It has been widely used in the treatment of various diseases. Studies have shown that Angelica sinensis polysaccharide is the main active substance in Angelica sinensis, which has good effects such as improving immunity, anti-oxidation, anti-tumor and anti-radiation.

[0003] In 2018, Professor Cao Wei of Northwest Agriculture and Forestry University isolated and extracted a novel anti-leukemia active APS-1 II polysaccharide from the root of Angelica sinensis. Structurally, APS-1 II polysaccharide has the following characteristics: 1) It has a highly branched 13-sugar as a repeating unit and contains two 3,5-branched arabinofuranosyl units; 2) It contains a challenging α-glucose-(1→3) glycosidic bond; 3) It contains three 1,2-cis-fucose glycosidic bonds, which are also difficult to achieve high stereoselective control. Biological activity studies have shown that APS-1 II polysaccharide can inhibit the activity of human leukemia K562 cells and mouse leukemia L1210 cells. Moreover, it can significantly prolong the lifespan of mice infected with the leukemia strain L1210.

[0004] However, there are currently no reports on the synthesis of the 13-sugar repeating unit and its substructure of APS-1 II polysaccharide other than extraction. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a method for a highly stereoselective 1,2-cis-fucosylation reaction and its application in the preparation of 13-sugar repeating units and substructure 9 sugars of Angelica polysaccharide APS-1 II. The promoter composition and fucose PTFAI donor provided by the present invention can adjust the stereoselectivity of the glycosylation reaction product. The method for a highly stereoselective 1,2-cis-fucosylation reaction provided by the present invention can achieve high stereoselective control of 1,2-cis-fucosidic bonds. The 13-sugar repeating units and substructure 9 sugars of Angelica polysaccharide APS-1 II provided by the present invention have a significant inhibitory effect on the activity of human leukemia K562 cells and mouse leukemia L1210 cells.

[0006] The present invention provides a promoter composition for adjusting the stereoselectivity of a glycosylation reaction, comprising iodotrimethylsilane (TMSI) and triphenylphosphine oxide (Ph3PO); the molar ratio of iodotrimethylsilane to triphenylphosphine oxide is 1:(5-10). The present invention provides a fucose PTFAI donor for a high stereoselective 1,2-cis-fucosylation reaction, wherein the O-3 and / or O-4 position of the fucose PTFAI donor is substituted by an acyl group. The promoter composition and the fucose PTFAI donor provided by the present invention can adjust the stereoselectivity of the glycosylation reaction product, so that it has high stereoselectivity.

[0007] The present invention provides a method for a highly stereoselective 1,2-cis-fucosylation reaction, which can achieve high stereoselective control of 1,2-cis-glycosidic bonds, the stereoselectivity of the glycosylated product is α / β>20:1, and the yield is 80-99%; at the same time, three consecutive 1,2-cis-fucosylation bonds are constructed with high stereoselectivity.

[0008] The invention provides a 13-sugar repeating unit of angelica polysaccharide APS-1 II and a substructure 9-sugar, which have a significant inhibitory effect on the activity of human leukemia K562 cells and mouse leukemia L1210 cells. DETAILED DESCRIPTION

[0009] The invention provides a promoter composition for high stereoselective 1,2-cis-fucosylation reaction, comprising iodotrimethylsilane and triphenylphosphine oxide.

[0010] In the present invention, the molar ratio of iodotrimethylsilane to triphenylphosphine oxide is 1:(5-10). In embodiments of the present invention, the molar ratio may be 1:5, 1:6, 1:7, 1:8, 1:9, or 1:10.

[0011] The present invention provides a fucose PTFAI donor for high stereoselective 1,2-cis-fucosylation reaction, wherein the O-3 and / or O-4 position of the fucose PTFAI donor is substituted by an acyl group. In the present invention, the acyl group preferably includes -Bz or -Lev.

[0012] The present invention provides the use of the promoter composition described in the above scheme or the fucose PTFAI donor described in the above scheme in a glycosylation reaction. The promoter composition and fucose PTFAI donor provided by the present invention can adjust the stereoselectivity of the glycosylation reaction product to make it have high stereoselectivity. Unless otherwise specified, the materials and equipment used in the present invention are all commercially available products.

[0013] The present invention provides a method for high stereoselective 1,2-cis-fucosylation reaction, comprising the following steps:

[0014] A fucose PTFAI donor, an alcohol acceptor, a promoter composition, a water scavenger and a polar organic solvent are mixed and subjected to a glycosylation reaction to obtain a glycosylated product having a 1,2-cis-fucose glycosidic bond; the stereoselectivity of the glycosylated product is α / β>20:1.

[0015] In the present invention, the fucose PTFAI donor preferably includes a monosaccharide PTFAI donor or a polysaccharide PTFAI donor; the monosaccharide PTFAI donor preferably has a structure shown in Formula 21; in Formula 21, R 2 is -Bn, -Me or -Nap, R 3 is -Bz, -Ac or -Lev; R 4 is -Bz or -Ac; the polysaccharide PTFAI donor preferably has a structure shown in Formula 9;

[0016]

[0017] In the present invention, the alcohol acceptor preferably has a structure shown in Formula 22, Formula 24, Formula 29 or Formula 10; HO(CH2)5NBnCbz Formula 22; H-OR Formula 24; in Formula 24, -OR has a structure shown in Formula 24d, Formula 24m or Formula 24v;

[0018]

[0019] In the present invention, the compound represented by the structure of Formula 22 is referred to: Castelli, Riccardo; Overkleeft, Herman S.; van der Marel, Gijsbert A.; Codée, Jeroen DC. (2013). 2,2-Dimethyl-4-(4-methoxy-phenoxy)

[0020] butanoate and 2,2-Dimethyl-4-azido Butanoate: Two New Pivaloate-ester-like Protecting Groups. Organic Letters, 15(9), 2270–2273. Preparation.

[0021] The compound with the structure shown in Formula 24 was prepared according to the reference: Penghua Li, Hanyingzi Fan, Qiang Tan, Guozhi Xiao; Highly Stereoselective Assembly of 1,2-cis-Arap Linkages; Organic Letters 202325 (16), 2788-2792.

[0022] In the present invention, when the monosaccharide PTFAI donor has a structure shown in Formula 21, the alcohol acceptor has a structure shown in Formula 22, Formula 24 or Formula 29;

[0023] When the polysaccharide PTFAI donor has a structure shown in Formula 9, the alcohol acceptor has a structure shown in Formula 10.

[0024] In the present invention, the formula 21 preferably has a structure shown in formula 21d:

[0025]

[0026] The present invention has no special requirements for the preparation of the compound with the structure represented by Formula 21d, and it can be obtained by methods well known in the art.

[0027] In the present invention, the accelerator composition is the accelerator composition described in the above scheme; the accelerator composition comprises trimethylsilyl imidazole and triphenylphosphine oxide. In the present invention, the polar organic solvent preferably comprises dichloromethane (DCM); the dehydrating agent preferably comprises molecular sieve (MS).

[0028] In the present invention, the mixing of the fucose PTFAI donor, the alcohol acceptor, the promoter composition, the water scavenger and the polar organic solvent preferably comprises: firstly mixing the fucose PTFAI donor, the alcohol acceptor, the triphenylphosphine oxide in the promoter composition and the polar organic solvent, then adding the water scavenger under the protection of an inert gas, performing a second mixing, and then dripping iodotrimethylsilane. In the present invention, the steps of adding the water scavenger, dripping iodotrimethylsilane and glycosidation reaction all need to be performed under the protection of an inert gas.

[0029] In the present invention, before the first mixing, the fucose PTFAI donor and the alcohol acceptor are preferably dehydrated. The present invention has no particular requirements for the dehydration method, and a method well known in the art can be used. In an embodiment of the present invention, the fucose PTFAI donor and the alcohol acceptor are preferably azeotroped with toluene; the number of azeotropes is preferably 3 times.

[0030] In the present invention, before the first mixing, the polar organic solvent is preferably dehydrated and impurities are removed. Before the first mixing, the dehydrating agent is preferably activated. The present invention has no particular requirements for the activation method of the dehydrating agent, and methods well known in the art can be used. The inert gas preferably includes argon.

[0031] In the present invention, the second mixing time is preferably 10 to 15 minutes. In an embodiment of the present invention, it can be 10 minutes, 12 minutes or 15 minutes.

[0032] In the present invention, the molar ratio of the fucose PTFAI donor and the alcohol acceptor is preferably (1-1.6): (1-1.6), and in embodiments of the present invention, it can be specifically 1:1, 1:1.5, 1:1.6, 1.45:1, 1.49:1, 1.5:1 or 1.6:1; the molar ratio of the fucose PTFAI donor and iodotrimethylsilane in the promoter composition is preferably (1-1.6):1, and in embodiments of the present invention, it can be specifically 1:1, 1.45:1, 1.49:1, 1.5:1 or 1.6:1; the concentration of the fucose PTFAI donor in the polar organic solvent is preferably 0.1-0.2 mol / L, and in embodiments of the present invention, it can be specifically 0.1 mol / L, 0.15 mol / L or 0.2 mol / L.

[0033] In the present invention, the time of the glycosidation reaction is preferably 24h to 5 days, and in embodiments of the present invention, it can be 24h, 38h, 48h, 72h, 80h, 96h or 4.5 days. The time of the glycosidation reaction of the present invention is preferably calculated from the completion of the dropwise addition of the iodotrimethylsilane. In the present invention, the temperature of the glycosidation reaction is preferably room temperature.

[0034] After the glycosidation reaction is completed, the present invention preferably performs post-treatment on the obtained reaction solution, and the post-treatment preferably includes diluting the obtained reaction solution with ethyl acetate (EA) and quenching the reaction with a saturated Na2S2O3 solution. The organic phase is washed with water and saturated brine, dried over anhydrous Na2SO4, filtered and concentrated, and finally the product is purified by silica gel column chromatography. The present invention has no special requirements for the specific method of the post-treatment, and a method well known in the art can be used.

[0035] The present invention provides an angelica polysaccharide APS-1 II 13 sugar repeating unit and a substructure 9 sugar thereof, wherein the angelica polysaccharide APS-1 II 13 sugar repeating unit has a structure shown in Formula 1, and the substructure 9 sugar has a structure shown in Formula 2:

[0036]

[0037] In the present invention, the method for preparing the substructure 9 sugar comprises the following steps:

[0038] The fucose PTFAI donor 12, the fucose acceptor 11, the first promoter composition, the first polar organic solvent and the first dehydrating agent are mixed to perform a first glycosylation reaction to obtain a first glycosylation product disaccharide 28; the Lev protecting group of the first glycosylation product disaccharide 28 is removed to obtain a disaccharide acceptor 29;

[0039] The fucose PTFAI donor 12 has a structure shown in formula 12; the fucose acceptor 11 has a structure shown in formula 24o; the first glycosylation product disaccharide 28 has a structure shown in formula 28; the disaccharide acceptor 29 has a structure shown in formula 29; the first promoter composition is the promoter composition described in the above scheme; the promoter composition includes iodotrimethylsilane and triphenylphosphine oxide;

[0040]

[0041] The present invention has no special requirements for the preparation of the compound of the structure represented by Formula 12, and it can be obtained by methods well known in the art.

[0042] In the present invention, the conditions of the first glycosidation reaction and the ratio of each raw material are the same as the conditions of the glycosidation reaction described above, and will not be repeated here.

[0043] In the present invention, removing the Lev protecting group from the first glycosylation product disaccharide 28 preferably includes the following steps: mixing the first glycosylation product disaccharide 28, a pyridine / AcOH mixed solvent and hydrazine hydrate (NH2NH2·H2O), removing the Lev protecting group to obtain a disaccharide receptor 29.

[0044] In the present invention, the volume ratio of pyridine and acetic acid in the pyridine-acetic acid mixed solvent is preferably 3:2; the molar amount of the first glycosylation product disaccharide 28 and the volume ratio of the pyridine-acetic acid mixed solvent is preferably 0.48mmol:4.7mL; the molar ratio of the first glycosylation product disaccharide 28 and hydrazine hydrate is preferably 1:(2.5-3.5), and in embodiments of the present invention, it can be specifically 1:2.5, 1:2.98, 1:3 or 1:3.5.

[0045] After the removal of the Lev protecting group, the present invention preferably performs post-treatment on the obtained reaction solution; the post-treatment preferably includes quenching and concentrating the obtained reaction solution with acetone, then diluting the mixture with ethyl acetate, washing with 4M HCl, saturated NaHCO3 solution and saturated brine, drying with anhydrous Na2SO4, filtering, concentrating, and finally separating and purifying with column chromatography. The present invention has no special requirements for the specific method of the post-treatment, and the method well known in the art can be used.

[0046] After obtaining the disaccharide acceptor 29, the present invention mixes the fucose PTFAI donor 21d with the disaccharide acceptor 29, a second promoter composition, a second polar organic solvent and a second dehydrating agent, and performs a second glycosidation reaction to obtain a trisaccharide 30;

[0047] The fucose PTFAI donor 21d has a structure shown in formula 21d; the trisaccharide 30 has a structure shown in formula 30;

[0048] The second accelerator composition is the accelerator composition described in the above scheme; the accelerator composition comprises iodotrimethylsilane and triphenylphosphine oxide;

[0049]

[0050] In the present invention, the conditions of the second glycosidation reaction and the ratio of each raw material are the same as the conditions of the glycosidation reaction described above, and will not be repeated here.

[0051] After obtaining the trisaccharide 30, the present invention selectively removes the protecting group STol from the trisaccharide 30 to obtain a trisaccharide intermediate.

[0052] In the present invention, the selective removal of the protecting group STol from the trisaccharide 30 preferably comprises the following steps:

[0053] The trisaccharide 30 is dissolved in an acetone aqueous solution, and then the resulting mixed solution is cooled, and trichloroisocyanuric acid (TCCA) is added to remove the STol protecting group to obtain a trisaccharide intermediate.

[0054] In the present invention, the volume ratio of acetone and water in the acetone aqueous solution is preferably 4:1; the molar amount of the trisaccharide 30 and the volume ratio of the acetone aqueous solution are preferably 0.19 mmol:4.6 mL; the molar ratio of the trisaccharide 30 and trichloroisocyanuric acid is preferably 1:1; the cooling is preferably cooled to 0°C; the time for removing the STol protecting group is preferably 10 hours, and the temperature is preferably room temperature.

[0055] After the removal of the STol protecting group, the present invention preferably performs post-treatment on the obtained reaction solution; the post-treatment preferably includes: diluting with ethyl acetate, washing with saturated NaHCO3 solution, water and saturated saline, drying with anhydrous Na2SO4, filtering, concentrating, and finally separating and purifying with column chromatography. The present invention has no particular requirements for the specific method of the post-treatment, and the method well known in the art can be used.

[0056] After obtaining the trisaccharide intermediate, the present invention mixes the trisaccharide intermediate, 2,2,2-trifluoro-N-phenylacetimidoyl chloride, a third polar organic solvent and a first carbonate, and performs a first substitution reaction to obtain a trisaccharide PTFAI donor 9 having a PTFAI protecting group; the trisaccharide PTFAI donor 9 has a structure shown in Formula 9;

[0057]

[0058] In the present invention, the third polar organic solvent preferably includes acetone; the first carbonate preferably includes potassium carbonate. In the present invention, the carbonate is used as an acid binding agent to neutralize HCl generated in the reaction.

[0059] In the present invention, the molar ratio of the trisaccharide intermediate and 2,2,2-trifluoro-N-phenylacetyl chloride is preferably 1:(1.8-2), and in embodiments of the present invention, it can be specifically 1:1.8, 1:1.86 or 1:2; the molar amount of the trisaccharide intermediate and the volume ratio of the third polar organic solvent are preferably 0.07 mmol:0.7 mL; the molar ratio of the 2,2,2-trifluoro-N-phenylacetyl chloride and the first carbonate is preferably 1:1.

[0060] In the present invention, the temperature of the first substitution reaction is preferably room temperature, and the time is preferably 10 hours.

[0061] After the first substitution reaction is completed, the present invention preferably performs post-treatment on the obtained reaction solution; the post-treatment preferably includes: concentration and column chromatography separation and purification. The present invention has no special requirements for the specific method of the post-treatment, and methods well known in the art can be used.

[0062] After obtaining the trisaccharide PTFAI donor 9, the present invention mixes the trisaccharide PTFAI donor 9, the hexasaccharide acceptor 10, the third promoter composition, the fourth polar organic solvent and the third water scavenger, and performs a third glycosidation reaction to obtain the nonasaccharide 31; the hexasaccharide 10 has a structure shown in formula 10; the nonasaccharide 31 has a structure shown in formula 31;

[0063] The third accelerator composition is the accelerator composition described in the above scheme; the accelerator composition comprises iodotrimethylsilane and triphenylphosphine oxide;

[0064]

[0065] In the present invention, the conditions of the third glycosidation reaction and the ratio of each raw material are the same as the conditions of the glycosidation reaction described above, and will not be repeated here.

[0066] In the present invention, the preparation of the hexasaccharide receptor 10 preferably comprises the following steps:

[0067] The arabinose PTFAI donor 18, the glucose PVB acceptor 19, the first activator, the fourth dehydrating agent and the fifth polar organic solvent are mixed to perform a fourth glycosylation reaction to obtain a reaction solution containing α-Araf-(1→6)-Glc disaccharide; the reaction solution containing α-Araf-(1→6)-Glc disaccharide, the arabinose acceptor 20, the second activator and N,N-dimethylformamide (DMF) are mixed to perform a fifth glycosylation reaction to obtain trisaccharide 26;

[0068] The arabinose PTFAI donor 18 has a structure shown in Formula 18; the glucose PVB acceptor 19 has a structure shown in Formula 19; the arabinose acceptor 20 has a structure shown in Formula 20; and the trisaccharide 26 has a structure shown in Formula 26;

[0069]

[0070] The present invention has no special requirements for the preparation of the compounds of structures represented by Formula 18 to Formula 20, and they can be obtained by methods well known in the art.

[0071] In the present invention, the first activator is preferably trimethylsilyl trifluoromethanesulfonate (TMSOTf); the fourth water removal agent is preferably a molecular sieve; and the fifth polar organic solvent is preferably dichloromethane.

[0072] In the present invention, the molar ratio of the arabinose PTFAI donor 18 to the glucose PVB acceptor 19 is preferably 1.2:1; the molar ratio of the arabinose PTFAI donor 18 to the first activator is preferably (3.5-4):1, and in embodiments of the present invention, it may be 3.5:1, 3.8:1 or 4:1. In the present invention, the mass ratio of the arabinose PTFAI donor 18 to the fourth water scavenger is preferably 1:(1.5-2.5), and in embodiments of the present invention, it may be 1:1.5, 1:2, 1:2.1, 1:2.5. In the present invention, the volume ratio of the molar amount of the arabinose PTFAI donor 18 to the fifth polar organic solvent is preferably 0.42 mmol:3.2 mL.

[0073] In the present invention, the mixing of the arabinose PTFAI donor 18, the glucose PVB acceptor 19, the first activator, the fourth dehydrating agent and the fifth polar organic solvent preferably includes: mixing and stirring the arabinose PTFAI donor 18, the glucose PVB acceptor 19, the fourth dehydrating agent and the fifth polar organic solvent, then cooling, and then dropping the first activator.

[0074] In the present invention, the mixing and stirring time is preferably 15 minutes; the cooling is preferably cooled to -40°C. In the present invention, the fourth glycosidation reaction time is preferably 2 hours, the temperature is preferably -40°C; the fourth glycosidation reaction time is preferably calculated from the completion of the dropwise addition of the first activator.

[0075] After obtaining the reaction solution containing α-Araf-(1→6)-Glc disaccharide, the present invention preferably does not perform post-treatment, and then mixes the reaction solution containing α-Araf-(1→6)-Glc disaccharide, arabinose receptor 20, a second activator, and N,N-dimethylformamide to perform a fifth glycosylation reaction to obtain trisaccharide 26.

[0076] In the present invention, mixing the reaction solution containing α-Araf-(1→6)-Glc disaccharide, arabinose acceptor 20, a second activator, and N,N-dimethylformamide preferably includes: heating the reaction solution containing α-Araf-(1→6)-Glc disaccharide, then adding N,N-dimethylformamide, performing a first stirring, then adding the second activator, performing a second stirring, then adding arabinose acceptor 20, heating the resulting reaction solution to room temperature, and performing a fifth glycosidation reaction.

[0077] In the present invention, the heating is preferably heated to 0°C; the temperature of the first stirring is preferably 0°C, and the time is preferably 15 minutes; the time of the second stirring is preferably 1.5 hours. In the present invention, the second activator is preferably N-iodosuccinimide (NIS) and trimethylsilyl trifluoromethanesulfonate (TMSOTf); the molar ratio of N-iodosuccinimide to trimethylsilyl trifluoromethanesulfonate is preferably 1:1. In the present invention, the NIS reacts with TMSOTf to release positively charged iodide ions to activate the PVB groups.

[0078] In the present invention, the arabinose receptor 20 is preferably added in the form of an arabinose receptor 20 solution; in the present invention, the solution of the arabinose receptor 20 is preferably obtained by dissolving the arabinose receptor 20 in dichloromethane; the concentration of the arabinose receptor 20 solution is preferably 0.29 mol / L.

[0079] In the present invention, the molar ratio of the arabinose receptor 20 (referring to pure arabinose receptor 20) and the second activator is preferably 1:(2.5-3.5), and in embodiments of the present invention, it can be specifically 1:2.5, 1:3 or 1:3.5; the molar ratio of the arabinose receptor 20 and N,N-dimethylformamide is preferably 1:(15.5-16.5), and in embodiments of the present invention, it can be specifically 1:15.5, 1:16 or 1:16.5.

[0080] The temperature of the fifth glycosidation reaction is preferably room temperature, and the time is preferably 10 h.

[0081] After completing the fifth glycosidation reaction, the present invention preferably performs post-treatment on the obtained reaction solution; the post-treatment preferably includes: quenching the reaction with triethylamine (Et3N), filtering, concentrating, and column chromatography separation and purification.

[0082] After obtaining the trisaccharide 26, the present invention removes the protecting group MP of the trisaccharide 26 to obtain a hemiacetal intermediate.

[0083] In the present invention, the removal of the protecting group MP of the trisaccharide 26 preferably comprises the following steps: dissolving the trisaccharide 26 in a toluene-acetonitrile aqueous solution (Toluene / MeCN / H2O), cooling, and adding cerium ammonium nitrate (CAN) to remove the protecting group MP.

[0084] In the present invention, the volume ratio of toluene, acetonitrile and water in the toluene-acetonitrile aqueous solution is preferably 3:5:3; the molar ratio of the trisaccharide 26 and the toluene-acetonitrile aqueous solution is preferably 1.85mmol:37mL; the molar ratio of the trisaccharide 26 and ammonium cerium nitrate is preferably 1:(2-2.5), and in the embodiment of the present invention, it can be specifically 1:2, 1:2.2, 1:2.28 or 1:2.5. In the present invention, the time for removing the protecting group MP is preferably 2h, and the temperature is preferably 0°C.

[0085] After the removal of the protecting group MP, the reaction mixture is preferably quenched with a saturated NaHCO3 solution, extracted three times with DCM, and the organic phase is washed with saturated brine, dried with Na2SO4, filtered, concentrated, and finally separated and purified by column chromatography.

[0086] After obtaining the hemiacetal intermediate, the present invention mixes the hemiacetal intermediate, a sixth polar organic solvent, 2,2,2-trifluoro-N-phenylacetylimidate chloride and a second carbonate to perform a second substitution reaction to obtain a trisaccharide PTFAI donor 17; the trisaccharide PTFAI donor 17 has a structure shown in Formula 17;

[0087]

[0088] In the present invention, the sixth polar organic solvent preferably includes acetone; and the second carbonate preferably includes potassium carbonate.

[0089] In the present invention, the molar ratio of the hemiacetal intermediate to 2,2,2-trifluoro-N-phenylacetyl chloride is preferably 1:(1.3-1.5), and in embodiments of the present invention, it can be specifically 1:1.3, 1:1.35 or 1:5; the molar ratio of the hemiacetal intermediate to the volume ratio of the sixth polar organic solvent is preferably 2.04 mmol:15.3 mL; the molar ratio of the 2,2,2-trifluoro-N-phenylacetyl chloride to the second carbonate is preferably 1:1.

[0090] In the present invention, the temperature of the second substitution reaction is preferably room temperature, and the time is preferably 10 hours.

[0091] After the first substitution reaction is completed, the present invention preferably filters and concentrates the reaction mixture, and then separates and purifies it by column chromatography.

[0092] After obtaining the trisaccharide PTFAI donor 17, the present invention mixes the trisaccharide PTFAI donor 17, the arabinose ABz acceptor 14, the fifth dehydrating agent, the seventh polar organic solvent and the third activator to perform a sixth glycosidation reaction to obtain a reaction solution containing a tetrasaccharide ABz intermediate.

[0093] In the present invention, the third activator is preferably trimethylsilyl trifluoromethanesulfonate; the fifth water removal agent is preferably a molecular sieve; and the seventh polar organic solvent is preferably dichloromethane.

[0094] In the present invention, the molar ratio of the trisaccharide PTFAI donor 17 to the arabinose ABz acceptor 14 is preferably 1.1:1; the molar ratio of the trisaccharide PTFAI donor 17 to the third activator is preferably (4-5):1, and in embodiments of the present invention, it may be 4:1, 4.5:1 or 5:1. In the present invention, the mass ratio of the trisaccharide PTFAI donor 17 to the fifth water scavenger is preferably 1:(3-3.5), and in embodiments of the present invention, it may be 1:3, 1:3.2 or 1:3.5. In the present invention, the volume ratio of the trisaccharide PTFAI donor 17 to the seventh polar organic solvent is preferably 0.09 mmol:0.4 mL.

[0095] In the present invention, mixing the trisaccharide PTFAI donor 17, the arabinose ABz acceptor 14, the fifth water removing agent, the seventh polar organic solvent and the third activator preferably includes: mixing and stirring the trisaccharide PTFAI donor 17, the arabinose ABz acceptor 14, the fifth water removing agent and the seventh polar organic solvent, then cooling, and then dropping the third activator.

[0096] In the present invention, the mixing and stirring time is preferably 15 minutes; the cooling is preferably cooled to -40°C. In the present invention, the sixth glycosidation reaction time is preferably 2 hours, the temperature is preferably -40°C; the sixth glycosidation reaction time is preferably calculated from the completion of the dropwise addition of the third activator.

[0097] After obtaining the reaction solution containing the tetrasaccharide ABz intermediate, the present invention preferably does not perform post-treatment, and then mixes the reaction solution containing the tetrasaccharide ABz intermediate, the arabinose PVB receptor 15 and the catalyst to perform the seventh glycosidation reaction to obtain a reaction solution containing the pentasaccharide intermediate.

[0098] In the present invention, mixing the reaction solution containing the tetrasaccharide ABz intermediate, the arabinose PVB receptor 15 and the catalyst preferably comprises: heating the reaction solution containing the tetrasaccharide ABz intermediate to room temperature, and then adding the arabinose PVB receptor 15 and the catalyst.

[0099] In the present invention, the arabinose PVB receptor 15 is preferably added in the form of an arabinose PVB receptor 15 solution; the arabinose PVB receptor 15 solution is preferably obtained by dissolving the arabinose PVB receptor 15 in dichloromethane; the concentration of the arabinose PVB receptor 15 solution is preferably 0.35 mol / L.

[0100] In the present invention, the catalyst is preferably added in the form of a catalyst solution; the catalyst solution is preferably obtained by dissolving the catalyst in dichloromethane; the concentration of the catalyst solution is preferably 0.12 mol / L. In the present invention, the molar ratio of the arabinose PVB receptor 15 (referring to the pure substance of arabinose PVB receptor 15) to the catalyst (referring to the pure substance of the catalyst) is preferably 7:1.2.

[0101] In the present invention, the temperature of the seventh glycosidation reaction is preferably room temperature, and the time is preferably 2 hours.

[0102] In the present invention, the catalyst preferably comprises triphenylphosphine gold trifluoromethanesulfonate (PPh3AuOTf). In the present invention, the PPh3AuOTf is preferably purchased or made by oneself. When made by oneself, the preparation of the catalyst preferably comprises the following steps:

[0103] Under argon protection and light-proof conditions, PPh3AuCl and AgOTf are added to dichloromethane in sequence and reacted for 10 minutes. In the present invention, the molar ratio of PPh3AuCl and AgOTf is preferably 1:1. The present invention has no special requirements for the amount of dichloromethane, which can be adjusted according to the actual reaction needs.

[0104] After obtaining the reaction solution containing the pentasaccharide intermediate, the present invention preferably does not perform post-treatment, and then mixes the reaction solution containing the pentasaccharide intermediate, the arabinose receptor 16, and the fourth activator to perform an eighth glycosidation reaction to obtain the hexasaccharide 27.

[0105] In the present invention, the fourth activator is preferably N-iodosuccinimide and trimethylsilyl trifluoromethanesulfonate; the molar ratio of N-iodosuccinimide to trimethylsilyl trifluoromethanesulfonate is preferably (1.5-1.7):1, and in the embodiments of the present invention, it can be specifically 1.5:1, 1.65:1 or 1.7:1.

[0106] In the present invention, before mixing the reaction solution containing the pentasaccharide intermediate, the arabinose receptor 16 and the fourth activator, it is preferred that the reaction solution containing the pentasaccharide intermediate is cooled. In the present invention, the cooling is preferably to -78°C.

[0107] In the present invention, the molar ratio of the arabinose receptor 16 to the fourth activator is preferably 1:(9.5-10), and in the embodiments of the present invention, it can be specifically 1:9.5, 1:9.86 or 1:10.

[0108] In the present invention, the temperature of the eighth glycosidation reaction is preferably -78°C, and the time is preferably 3 hours.

[0109] After the eighth glycosidation reaction is completed, the present invention preferably uses Et3N to quench the reaction and filter, concentrate, and finally separate and purify by column chromatography.

[0110] After obtaining the hexasaccharide 27, the present invention selectively removes the TIPS protecting group from the hexasaccharide 27 to obtain the hexasaccharide 10.

[0111] In the present invention, the selective removal of the TIPS protecting group from the hexasaccharide 27 preferably comprises the following steps: dissolving the hexasaccharide 27 in a methanol-dichloromethane mixed solvent (MeOH / DCM), cooling, and then dropping acetyl chloride (AcCl) to remove the TIPS protecting group.

[0112] In the present invention, the cooling is preferably to -20°C; and the removal time of the TIPS protecting group is preferably 48 hours.

[0113] In the present invention, the volume ratio of methanol to dichloromethane in the methanol-dichloromethane mixed solvent is preferably 1:1; the molar amount of the hexasaccharide 27 and the volume ratio of the methanol-dichloromethane mixed solvent are preferably 0.07mmol:0.68mL; the concentration of the acetyl chloride in the methanol-dichloromethane mixed solvent is preferably 1mol / L.

[0114] After the removal of the TIPS protecting group, the present invention preferably uses a saturated NaHCO3 solution to quench the reaction, then extracts three times with DCM, washes the organic phase with water and saturated brine, dries over anhydrous Na2SO4, filters, concentrates, and finally separates and purifies by column chromatography.

[0115] In the present invention, the arabinose ABz receptor 14 has a structure shown in Formula 14; the arabinose PVB receptor 15 has a structure shown in Formula 15; the arabinose receptor 16 has a structure shown in Formula 16;

[0116]

[0117] The present invention has no special requirements for the preparation of the compounds of structures represented by Formula 14 to Formula 17, and they can be obtained by methods well known in the art.

[0118] After obtaining the nonasaccharide 31, the present invention selectively removes the Bz and Lev protecting groups in the nonasaccharide 31, and hydrogenolyzes the Bn and Cbz groups to obtain the substructure of the Angelica polysaccharide APS-1 II repeating unit.

[0119] In the present invention, the selective removal of the Bz and Lev protecting groups in the nonasaccharide 31 preferably comprises: dissolving the nonasaccharide 31 in a methanol-dichloromethane mixed solvent, then adding sodium methoxide (NaOMe), and adjusting the pH value to 11, stirring at room temperature, and then neutralizing the reaction with 4M HCl to a pH value of 7, and then filtering, concentrating, separating and purifying to obtain an intermediate.

[0120] In the present invention, the volume ratio of methanol to dichloromethane in the methanol-dichloromethane mixed solvent is preferably 1:1; the molar amount of the nonasaccharide 31 and the volume ratio of the methanol-dichloromethane mixed solvent are preferably 0.03 mmol:3 mL.

[0121] After obtaining the intermediate, the present invention hydrogenates the Bn and Cbz groups in the intermediate to obtain the substructure 9 sugar.

[0122] In the present invention, the hydrogenolysis preferably comprises: dissolving the intermediate and palladium carbon (Pd / C) in a methanol-acetic acid aqueous solution (MeOH / H2O / HOAc), stirring at room temperature under a hydrogen atmosphere, and then filtering, concentrating, separating and purifying.

[0123] In the present invention, the mass ratio of the intermediate to palladium carbon is preferably 1:(1.4-1.6), and in embodiments of the present invention, it can be specifically 1:1.4, 1:1.54 or 1:1.6. In the present invention, the volume ratio of methanol, water and acetic acid is preferably 4mL:0.5mL:0.01mL. In the present invention, the molar amount of the intermediate and the total volume ratio of methanol-acetic acid aqueous solution are preferably 0.024mmol:4.51mL. In the present invention, the time of stirring at room temperature is preferably 10h.

[0124] In the present invention, the preparation method of the 13-sugar repeating unit of the Angelica polysaccharide APS-1 II comprises the following steps:

[0125] According to the preparation method described in the above scheme, nonasaccharide 31 was obtained;

[0126] The Lev protecting group of the nonasaccharide 31 was removed to obtain nonasaccharide 8.

[0127] In the present invention, removing the Lev protecting group of the nonasaccharide 31 preferably includes: dissolving the nonasaccharide 31 in a pyridine-acetic acid mixed solvent (pyridine / AcOH), adding hydrazine hydrate, stirring at room temperature overnight, quenching the reaction with acetone, concentrating, then diluting the solution with ethyl acetate, and washing with 4M HCl, saturated NaHCO3 solution and saturated brine, then drying with anhydrous Na2SO4, filtering, concentrating, and finally separating and purifying by column chromatography.

[0128] In the present invention, the volume ratio of pyridine and acetic acid in the pyridine-acetic acid mixed solvent is preferably 3:2; the molar amount of the nonasaccharide 31 and the volume ratio of the pyridine-acetic acid mixed solvent is preferably 0.97 mmol:1 mL; the molar ratio of the nonasaccharide 31 and hydrazine hydrate is preferably (3-4):1, and in the embodiments of the present invention, it can be specifically 3:1, 3.3:1 or 4:1.

[0129] After obtaining the nonasaccharide 8, the present invention mixes the glucose PTFAI donor 5, the glucose ABZ acceptor 6, the dehydrating agent, the first polar organic solvent and the first activating agent to carry out a ninth glycosidation reaction to obtain a reaction solution containing the disaccharide ABz intermediate.

[0130] In the present invention, the first activator is preferably trifluoromethanesulfonic acid; the first polar organic solvent is preferably dichloromethane; and the dehydrating agent is preferably a molecular sieve.

[0131] In the present invention, mixing the glucose PTFAI donor 5, the glucose ABZ acceptor 6, the dehydrating agent, the first polar organic solvent and the first activator preferably includes: mixing and stirring the glucose PTFAI donor 5, the glucose ABZ acceptor 6, the dehydrating agent and the first polar organic solvent, then cooling, and adding the first activator dropwise.

[0132] In the present invention, the molar ratio of the glucose PTFAI donor 5 and the glucose ABZ acceptor 6 is preferably 1:1; the molar amount of the glucose PTFAI donor 5 and the volume ratio of the first polar organic solvent are preferably 0.04mmol:0.4mL; the mass ratio of the glucose PTFAI donor 5 and the dehydrating agent is preferably 1:(10-12), and in an embodiment of the present invention, it can be specifically 1:10, 1:11 or 1:12; the molar ratio of the glucose PTFAI donor 5 and the first activator is preferably 4:1.

[0133] In the present invention, the mixing and stirring time is preferably 15 minutes; the cooling is preferably cooled to -40°C; the temperature of the ninth glycosidation reaction is preferably -40°C, and the time is preferably 2 hours.

[0134] After obtaining the reaction solution containing the disaccharide ABz intermediate, the present invention preferably does not perform post-treatment, and then mixes the reaction solution containing the disaccharide ABz intermediate, the arabinose PVB receptor 7 and the catalyst to perform the tenth glycosidation reaction to obtain a reaction solution containing the tetrasaccharide PVB intermediate.

[0135] In the present invention, mixing the reaction solution containing the disaccharide ABz intermediate, the arabinose PVB receptor 7 and the catalyst preferably comprises: heating the reaction solution containing the disaccharide ABz intermediate, and then adding the arabinose PVB receptor 7 and the catalyst.

[0136] In the present invention, the heating is preferably heated to room temperature. In the present invention, the arabinose PVB receptor 7 is preferably added in the form of an arabinose PVB receptor 7 solution; the arabinose PVB receptor 7 solution is preferably obtained by dissolving the arabinose PVB receptor 7 in dichloromethane; the concentration of the arabinose PVB receptor 7 solution is preferably 0.2 mol / L.

[0137] In the present invention, the catalyst is preferably added in the form of a catalyst solution; the catalyst solution is preferably obtained by dissolving the catalyst in dichloromethane; and the concentration of the catalyst solution is preferably 0.05 mol / L.

[0138] In the present invention, the catalyst preferably includes triphenylphosphine gold trifluoromethanesulfonate. In the present invention, the PPh3AuOTf is preferably purchased or homemade. When homemade, the preparation of the catalyst preferably includes: adding PPh3AuCl and AgOTf to dichloromethane in sequence under argon protection and light protection conditions, and reacting for 10 minutes. In the present invention, the molar ratio of PPh3AuCl and AgOTf is preferably 1:1; the present invention has no special requirements for the amount of dichloromethane, which can be adjusted according to the actual reaction needs.

[0139] In the present invention, the molar ratio of the arabinose PVB acceptor 7 (pure substance) to the catalyst (pure substance) is preferably 8:1; the molar ratio of the arabinose PVB acceptor 7 (pure substance) to the glucose PTFAI donor 5 is preferably 1:1;

[0140] In the present invention, the temperature of the tenth glycosidation reaction is preferably room temperature, and the time is preferably 2 hours.

[0141] After obtaining the reaction solution containing the tetrasaccharide PVB intermediate, the present invention preferably does not perform post-treatment, and then mixes the reaction solution containing the tetrasaccharide PVB intermediate, the nonasaccharide 8, and the second activator to perform the eleventh glycosidation reaction to obtain the tridecasaccharide 35.

[0142] In the present invention, the second activator is preferably N-iodosuccinimide and trifluoromethanesulfonic acid; the molar ratio of N-iodosuccinimide and trifluoromethanesulfonic acid is preferably 5:1; the molar ratio of the nonasaccharide 8 and the second activator is preferably 5:1; the molar ratio of the nonasaccharide 8 and the arabinose PVB receptor 7 (pure substance) is preferably 3:0.4. In the present invention, the time of the eleventh glycosylation reaction is preferably 2h.

[0143] After the eleventh glycosidation reaction is completed, the present invention preferably quenches the obtained reaction solution with triethylamine, and then filters, concentrates and purifies it.

[0144] After obtaining the tridecanes 35, the present invention removes the protecting group of the tridecanes 35 to obtain the 13-sugar repeating unit of the angelica polysaccharide APS-1 II.

[0145] In the present invention, removing the protecting group of the tridecanose 35 preferably comprises: dissolving the tridecanose 35 in a methanol-dichloromethane mixed solvent, then adding sodium methoxide, adjusting the pH value to 11, stirring at room temperature for 8 days, then neutralizing with 4M HCl to a pH value of 7, then filtering, concentrating, separating and purifying to obtain an intermediate; dissolving the intermediate and palladium carbon in a methanol-acetic acid aqueous solution, stirring at room temperature for 10 hours under a hydrogen atmosphere, then filtering, concentrating, separating and purifying.

[0146] In the present invention, the volume ratio of methanol to dichloromethane in the methanol-dichloromethane mixed solvent is preferably 1:1; the molar amount of the tridecasaccharide 35 and the volume ratio of the methanol-dichloromethane mixed solvent are preferably 0.015 mmol:3 mL.

[0147] In the present invention, the mass ratio of the intermediate to palladium carbon is preferably 1: (2.5-3.5), and in embodiments of the present invention, it can be specifically 1: 2.5, 1: 2.9 or 1: 3.5. In the present invention, the volume ratio of methanol, water and acetic acid is preferably 4 mL: 0.5 mL: 0.01 mL. In the present invention, the molar amount of the intermediate and the total volume ratio of methanol-acetic acid aqueous solution are preferably 0.014 mmol: 4.51 mL.

[0148] After the removal of the protecting group of the tridecasaccharide 35 is completed, the present invention preferably filters the obtained reaction solution, and then concentrates and purifies it.

[0149] In the present invention, the nonasaccharide 8 has a structure shown in Formula 8; the glucose PTFAI donor 5 has a structure shown in Formula 5; the glucose ABZ acceptor 6 has a structure shown in Formula 6; the arabinose PVB acceptor 7 has a structure shown in Formula 7; the tridecanes 35 has a structure shown in Formula 35; the 13-sugar repeating unit 1 has a structure shown in Formula 1;

[0150]

[0151] The present invention has no special requirements for the preparation of the compounds of structures represented by Formula 5 to Formula 8, and they can be obtained by methods well known in the art.

[0152] The present invention provides the use of the Angelica polysaccharide APS-1 II repeating unit and its substructure described in the above scheme or the Angelica polysaccharide APS-1 II repeating unit and its substructure prepared by the preparation method described in the above scheme in the preparation of a drug for inhibiting leukemia cell proliferation.

[0153] To further illustrate the present invention, a highly stereoselective 1,2-cis-fucosylation reaction promoter composition, a fucose PTFAI donor and its application, a highly stereoselective 1,2-cis-fucosylation reaction method, 13-sugar repeating units of Angelica polysaccharide APS-1 II, substructure 9 sugars and their preparation methods and applications are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0154] Example 1

[0155] Preparation of 2-O-benzyl-3,4-O-benzoyl-N-trifluoroacetimidate-L-pyranose (21d):

[0156]

[0157] S3 (S3 reference: Jun Zhou, Liping Yang, and Wenhao Hu; Stereoselective Synthesis of a Sulfated Tetrasaccharide Corresponding to a Rare Sequence in the Galactofucan Isolated from Sargassum polycystum; Org. Chem. 2014, 79, 4718-4726. Preparation) (4.46 g, 7.61 mmol) was dissolved in Py (15 mL), and BzCl (2.64 mL, 3 eq.) and DMAP (185.7 mg, 1.52 mmol, 0.2 eq.) were added, and the reaction was allowed to react at room temperature overnight. After the reaction was completed, the reaction was quenched with water, extracted with DCM, dried over anhydrous Na2SO4, filtered, and concentrated. Purification by silica gel column chromatography (PE / EA5 / 1) gave 27 (4.32 g, yield 99%). 27 (4.32 g, 7.60 mmol) was dissolved in acetone / water (61 / 15.2 mL) and cooled to 0°C. TCCA (1.79 g, 7.60 mmol) was added and the mixture was heated to room temperature and reacted overnight. The mixture was extracted with DCM, washed with saturated NaHCO3, water and saturated water, dried over anhydrous Na2SO4, filtered and concentrated. The above intermediate (400 mg, 0.86 mmol) and 2,2,2-trifluoro-N-phenylacetyl chloride (180 mg, 0.86 mmol) were dissolved in acetone (3.4 mL), and K2CO3 (119 mg, 0.86 mmol) was added. The mixture was reacted at room temperature overnight, filtered and concentrated. The mixture was purified by silica gel column chromatography (PE / EA 10 / 1, containing 0.1% Et3N) to give 21d (531 mg, yield 97%). 1 HNMR(400MHz, CDCl3)δ7.94-7.84(m,2H),7.73-7.69(m,2H),7.55-7.49(m,1H),7.41-7.34(m,3H),7.27-7.02(m,10H),6.80-6.71(m,2H),5.70- 5.66(m,1H),5.50(s,1H),5.33(s,1H),4.74(d,J=12.0Hz,1H),4.61(d,J =12..0Hz,1H),4.66-4.61(m,1H),4.10-3.90(m,1H),1.20-1.12(m,3H); 13C NMR (100MHz, CDCl3) δ165.9,165.86,165.6,165.5,143.7,143.5,137.4,137.3,133.5,1 33.49,133.3,133.2,130.0,129.9,129.8,129.7,129.5,129.48,129.4,128.9,128.8,12 8.7,128.5,128.44,128.4,128.38,128.36,128.03,128.0,124.5,119.4,97.5,75.4,75 .0,73.2,73.1,72.5,71.8,71.2,70.6,70.4,68.0,16.3,16.2.HRMS(ESI),m / zcalcd.for C 35 H 30 F3NO7Na[M+Na] + 656.1872, found:656.1872.

[0158] Example 2

[0159] The synthesis of (trans-3,7-methyl-2,6-octadienyl)-2-O-benzyl-3,4-O-benzoyl-α-L-pyranose (25d) is as follows:

[0160]

[0161] The glycosylation reaction was carried out according to the preparation steps of Example 1 for 24 h, except that donor 21d (88 mg, 0.14 mmol) and acceptor 24d (compound with structure shown in Formula 24, reference: Penghua Li, Hanyingzi Fan, Qiang Tan, Guozhi Xiao; Highly Stereoselective Assembly of 1,2-cis-Arap Linkages; Organic Letters 202325 (16), 2788-2792.) (32 mg, 0.21 mmol, 1.5 equiv.), Ph3PO (232 mg, 0.83 mmol, 6 equiv.), DCM (1.4 mL), Molecular sieves (120 mg) and TMSI (20 μL, 0.14 mmol, 1 equivalent). Purification by silica gel column chromatography (PE / EA=10 / 1) gave 25d (75 mg, yield 90%, α / β>20:1) as syrup. [α] D 26 = -170.11 (c 0.27, CHCl3); 1HNMR(400MHz, CDCl3) δ7.96(d,J=7.3Hz,2H),7.82(d,J=7.4Hz,2H),7.59(t,J=7.4Hz,1H),7.47-7.42(m,3H),7.3 1-7.24(m,7H),5.75(dd,J=10.5,3.3Hz,1H),5.66(d,J=2.6Hz,1H),5.44(t,J=6.5Hz,1H),5.12(d,J=6.5Hz,1H), 5.04(d,J=3.4Hz,1H,1-H),4.67(d,J=12.0Hz,1H),4.64(d,J=12.0Hz,1H),4.36(q,J=6.3Hz,1H),4.26-4.16(m,2 H),4.12(dd,J=10.5,3.5Hz,1H),2.29-2.06(m,2H),1.72(s,1H),1.70(s,2H),1.63(s,1H),1.20(d,J=6.5Hz,2H); 13 C NMR (100MHz, CDCl3) δ165.9,165.5,141.2,138.0,133.2,132.8,131.8,130.0,129.8,129.6,128.4,128.3,128.2,128.0 ,127.8,123.9,119.9,96.0(1-C),73.3,72.6,70.7,64.8,64.2,39.7,26.5,25.7,17.7,16.5,16.2.HRMS(ESI)calcdfor C 37 H 42 O7Na[M+Na] + 621.2823, found 621.2820.

[0162] Example 3

[0163] The synthesis of methyl-3-O-(2-O-benzyl-3,4-O-benzoyl-α-L-pyranose fucosyl)-2,3,6-O-benzyl-α-D-pyranose glucose (25m) is as follows:

[0164]

[0165] The glycosylation reaction was carried out for 52 hours according to the preparation procedure of Example 1, except that the donor 21d (158.6 mg, 0.25 mmol, 1.5 eq.) and the acceptor 24m (77.5 mg, 0.17 mmol), Ph3PO (418 mg, 1.5 mmol, 9 eq.), DCM (1.7 mL), Molecular sieves (230 mg) and TMSI (34 μL, 0.25 mmol, 1.5 equivalents). Purification by silica gel column chromatography (PE / EA=5 / 1) gave 25m (127 mg, yield 96%, α / β>20:1) as a white solid. [α] D 25.2 = -128.57 (c 0.35, CHCl3); 1 H NMR (400MHz, CDCl3) δ7.77(d,J=7.4Hz,2H),7.70(d,J=7.5Hz,2H),7.46-6.95(m,2 6H),5.77(s,1H,1-H),5.73(d,J=10.6Hz,1H),5.16(s,1H),4.67(q,J=10.9Hz,2H) ,4.60-4.55(m,5H,1'-H),4.44(d,J=11.9Hz,1H),4.38-4.32(m,2H),4.24(t,J=8. 8Hz,1H),4.98-3.95(m,1H),3.78-3.65(m,5H),3.24(s,3H),0.59(d,J=5.9Hz,3H); 13 C NMR (100MHz, CDCl3) δ166.0,165.6,138.3,138.0,137.8,137.7,133.1,132.9, 130.1,129.9,129.8,129.7,128.6,128.5,128.4,128.3,128.2,128.1,127.9,1 27.84,127.8,127.65,127.6,97.7(1'-C),96.6(1-C),81.7,77.0,75.4,74.1,7 3.7,73.0,72.7,72.5,72.3,70.5,70.4,68.8,64.5,55.2,15.6.HRMS(ESI),m / z calcd.For C 55 H 56 O 12 Na[M+Na] + 931.3664, found 931.3666.

[0166] Example 4

[0167] The synthesis of simvastatin-2-O-benzyl-3,4-O-benzoyl-α-L-pyranose (25v) is as follows:

[0168]

[0169] The glycosylation reaction was carried out for 4.5 days according to the preparation procedure of Example 1, except that the donor 21d (124 mg, 0.20 mmol) and the acceptor 24v (122 mg, 0.29 mmol, 1.5 eq.), Ph3PO (333.6 mg, 1.20 mmol, 6 eq.), DCM (2.0 mL), Molecular sieves (240 mg) and TMSI (28.4 μL, 0.20 mmol, 1 equivalent). Purification by silica gel column chromatography (PE / EA=3 / 1) gave 25v (137 mg, yield 80%, α / β>20:1) as a white solid. [α] D 20.1 = -36.50 (c 0.24, CHCl3); 1 HNMR (400MHz, CDCl3) δ7.89(d,J=7.5Hz,2H),7.73(d,J=7.5Hz,2H),7.53(t,J=7.4Hz,1H),7.42-7.36(m,3H),7.23-7.17(m,7H),5.90(d,J =9.6Hz,1H),5.69(dd,J=9.2,6.3Hz,1H),5.61-5.59(m,2H),5.41(s,1H),5.23(d,J=2.6Hz,1H),5.02(d,J=3.4Hz,1H,1-H),4.64-4.57(m, 3H),4.25(q,J=6.2Hz,1H),4.15(s,1H),4.08-4.05(m,1H),2.78(dd,J=17.3,3.2Hz,1H),2.68(dd,J=17.4,5.1Hz,1H),2.35-2.24(m,2H), 2.14-2.06(m,2H),1.84-1.76(m,4H),1.58-1.35(m,6H),1.13(d,J=6.5Hz,3H),1.05(s,6H),1.00(d,J=7.4Hz,3H),0.76(t,J=7.6Hz,6H); 13C NMR (100MHz, CDCl3) δ178.1,169.9,166.2,165.8,138.3,133.7,133.4,133.3,1 31.9,130.2,130.1,130.0,128.9,128.81,128.8,128.6,128.3,128.1,97.3(1-C ),77.8,73.7,73.3,72.6,70.9,69.9,68.2,66.1,43.4,38.0,37.3,37.0,33.6,3 3.4,33.3,31.0,27.7,25.21,25.2,24.1,23.4,16.5,14.3,9.8.HRMS(ESI)calcd for C 52 H 62 O 11 Na[M+Na] + 885.4184, found885.4182.

[0170] Example 5: Synthesis of substructure 2. Synthesis of acceptor 10: 1) p-methoxyphenyl (2-O-benzoyl-5-O-triisopropylsilyl-α-L-arabinofuranose) (20);

[0171]

[0172] The above-mentioned hemiacetal intermediate S8 (S8 reference: Zhang Y, Chen Z, Huang Y, He S, Yang X, Wu Z, Wang X, Xiao G. Modular Synthesis of Nona-Decasaccharide Motif from Psidiumguajava Polysaccharides: Orthogonal One-Pot Glycosylation Strategy. Angew Chem Int Ed Engl. 2020, 59, 7576-7584.) (3.64 g, 6.60 mmol) and ABzOH (1.85 g, 9.91 mmol) were dissolved in dry DCM (33 mL), and DMAP (807 mg, 6.60 mmol) and EDCI (2.28 g, 11.89 mmol) were added. Stir at room temperature for 5 hours. After the reaction was completed, it was concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 6 / 1) gave the intermediate (4.50 g, 95%, α / β3:1). The above intermediate (1.98 g, 2.76 mmol) and 4-methoxyphenol (377 mg, 3.04 mmol) were added to dry DCM (26.6 ml) Molecular sieves (2.53 g). After stirring at room temperature for 15 minutes, freshly prepared PPh3AuOTf in CH2Cl2 solution (1 mL, 0.44 M) was added. The reaction was stirred overnight, then quenched with Et3N (1 mL), filtered and concentrated. Column chromatography (petroleum ether / ethyl acetate, 10 / 1) was used to obtain the intermediate (1.81 g, quant). The above intermediate (1.81 g, 2.76 mmol) was then dissolved in DCM / H2O (27.5 ml, v / v 10 / 1) and DDQ (689 mg, 3.04 mmol) was added. The reactants were stirred at room temperature for 10 hours, diluted with EtOAc, and washed with saturated Na2S2O3 solution, water and saturated brine. Drying over anhydrous Na2SO4, filtering and concentrating. Column chromatography (petroleum ether / ethyl acetate, 5 / 1) was used to obtain colorless syrup 20 (1.54 g, 77%). [α] D 25 =-27.88 (c 0.16, CHCl3). 1 H NMR (400MHz, CDCl3) δ8.05(d,J=7.0Hz,2H),7.60(t,J=7.5Hz,1H),7.46(t,J=7.8Hz,2H),7.05(d,J=9.0Hz,2H),6.84(d,J=9.2Hz,2H),5.79(s, 1H,H-1),5.40(dd,J=3.0,1.4Hz,1H),4.40(m,1H),4.35(m,1H),3.97(d ,J=4.4Hz,2H),3.78(s,3H),3.34(d,J=4.4Hz,1H),1.19-0.95(m,21H). 13 C NMR (100MHz, CDCl3) δ165.96,154.28,149.55,132.81,129.02,128.23,127.66,117.44,113.73,104. 05,85.84,83.88,76.55,76.23,75.91,75.87,62.05,54.80,17.09,17.08,11.10.HRMS(ESI)calcdfor C 68 H 64 O 12 Na[M+Na] + 1095.4290, found 1095.4299.

[0173] 2) o-(1-phenylvinyl)-2,3,4-O-benzyl-β-D-pyranose benzoate (19)

[0174]

[0175] A solution of S9 (Shen K, Lowary TL. Synthesis of the Mycobacterium tuberculosis Canetti Lipooligosaccharide II Nonasaccharide. Org Lett. 2022, 24, 6428-6432) (4.30 g, 6.25 mmol) and PVBOH (2.10 g, 9.38 mmol) in dry DCM (31.3 ml) was added with DMAP (764 mg, 6.25 mmol), EDCI (1.75 g, 11.25 mmol) and DIPEA (3.30 ml, 18.75 mmol). The resulting mixture was stirred at room temperature for 10 hours. After completion, it was concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 30:1-20:1) gave colorless syrup 19 (4.11 g, 91%, α / β=1.5 / 1). The above intermediate (1.84 g, 2.06 mmol, βisomer) was then dissolved in dry THF (10 mL), and HF / pyridine (70%, 1.8 mL, 20.6 mmol) was added dropwise. The resulting mixture was stirred at room temperature for 4 hours, then quenched with Et3N, diluted with ethyl acetate, washed with saturated NaHCO3 solution and saturated brine, dried over anhydrous Na2SO4, and concentrated. Column chromatography (petroleum ether / ethyl acetate, 5 / 1) was used to separate and purify 19 as a colorless syrup (1.16 g, 86%). [α] D 25 =-18.00 (c 0.18, CHCl3). 1 H NMR (400MHz, CDCl3) δ7.83(d,J=6.4Hz,1H),7.46(td,J=7.5,1.4Hz,1H),7.35-7.25(m,2H),7.24-7.06(m,20H),5.64(s,1H),5.52( d,J=8.0Hz,1H),5.16-5.06(m,1H),4.81-4.66(m,3H),4.66-4.50(m,3H),3.65-3.55(m,2H),3.52-3.36(m,3H),3.32-3.24(m,1H). 13C NMR (100MHz, CDCl3) δ165.2,149.5,143.70,140.74,138.4,138.1,138.0,132.7,132.0,130.7,129.4,128.6,128.6,128.5,128.30,128.2,128 .13,128.07,128.0,127.9,127.9,127.6,126.7,114.3,94.5,84.7,81.1,77.6,77.2,77.0,76.9,75.8,75.7,75.2,75.0,61.4.HRMS(ESI)calcd for C 42 H 40 O7Na[M+Na] + 679.2666, found 679.2672.

[0176] 3) Synthesis of trisaccharide (17), the reaction equation is as follows:

[0177]

[0178] PTFAI donor 18 (18 Reference: Zhang Y, Chen Z, Huang Y, He S, Yang X, Wu Z, Wang X, Xiao G. Modular Synthesis of Nona-Decasaccharide Motiffrom Psidium guajava Polysaccharides: Orthogonal One-Pot Glycosylation Strategy. Angew Chem Int Ed Engl. 2020, 59, 7576-7584.) (255 mg, 0.42 mmol), PVB acceptor 19 (230 mg, 0.35 mmol) and newly activated MS (300 mg), MS (223 mg) was stirred in dry DCM (3.2 mL) for 15 minutes and then cooled to -40 ° C. TMSOTf (19 μL, 0.11 mmol) was added dropwise to the mixture. After stirring for another 2 h at -40 ° C, the reaction mixture was heated to 0 ° C and then DMF (362 μL, 4.67 mmol) was added. After stirring at 0 ° C for 15 minutes, NIS (99 mg, 0.44 mmol) and TMSOTf (80 μL, 0.44 mmol) were added. After 1.5 hours, the receptor 20 (151 mg, 0.29 mmol) was dissolved in DCM (1 mL) and added to the reaction system. The reaction mixture was heated to room temperature. The resulting mixture was stirred at room temperature for 10 hours, then quenched with Et3N (1 mL) and filtered, concentrated, and purified by column chromatography (petroleum ether / ethyl acetate = 6 / 1) to obtain colorless syrup 26 (230 mg, yield 58%). 26 (2.52 g, 1.85 mmol) was dissolved in toluene / acetonitrile / H2O (total volume 37 mL, v / v / v=3 / 5 / 3), cooled to 0°C, and then cerium ammonium nitrate (CAN) (2.31 g, 4.21 mmol) was added to remove the p-methoxyphenyl (MP) group at the anomeric position of 26 to generate hemiacetal. After stirring at 0°C for 2 hours, the reaction mixture was quenched with saturated NaHCO3 solution, extracted 3 times with DCM, and the organic phase was washed with saturated brine, dried over Na2SO4, filtered and concentrated. Column chromatography (petroleum ether / ethyl acetate volume ratio = 4 / 1) was used to obtain a light yellow syrup intermediate (1.92 g, 83%). The above intermediate (1.57 g, 2.04 mmol) was dissolved in acetone (15.3 mL), and then 2,2,2-trifluoro-N-phenylacetimidoylchloride (568 mg, 2.75 mmol) and anhydrous potassium carbonate (378 mg, 2.75 mmol) were added for substitution reaction. The mixture was stirred at room temperature for 10 hours. After the reaction was completed, the reaction mixture was filtered and concentrated. Column chromatography separation and purification (volume ratio of petroleum ether / ethyl acetate = 50 / 1, containing 3% Et3N) gave colorless syrup 17 (2.18 g, quant (quantitative yield, 100%), α / β>20 / 1). 1HNMR(400MHz, CDCl3) δ7.99(d,J=8.3Hz,2H),7.92(d,J=8.3Hz,2H),7.54(q,J=7.7Hz,2H),7.43-7.14 (m,34H),7.07(t,J=7.5Hz,1H),6.88(d,J=7.7Hz,2H),5.74(s,1H),5.38(s,1H),5.11(s,1H),5.06(s, 1H),4.95(t,J=10.0Hz,2H),4.84(d,J=11.0Hz,1H),4.71(q,J=9.6Hz,5H),4.62-4.40(m,5H),4.26(s ,1H),4.07(s,3H),3.99-3.84(m,4H),3.81-3.67(m,2H),3.56(dd,J=14.9,10.6Hz,4H),1.03(s,21H). 13 C NMR (100MHz, CDCl3) δ164.46,164.10,143.01,138.10,137.93,137.61,137.27,137.02,132.58,132.37,129.04,129.00,128.95, 128.71,128.33,127.84,127.67,127.58,127.55,127.49,127.42,127.15,127.09,127.02,126.86,126.82,126.78,126.74,126.7 2,126.69,126.65,126.53,123.30,118.82,105.58,97.31,85.34,82.28,81.21,80.95,80.64,80.54,79.09,76.69,76.55,76.43, 76.23,75.91,74.72,74.02,72.58,72.07,71.30,70.02,68.03,65.03,61.81,28.91,17.13,17.09,11.09,11.01.HRMS(ESI)calcd for C 82 H 90 NO 16 SiNa[M+Na] + 1452.5900, found 1452.5900.

[0179] 4) Preparation of o-(1-phenylvinyl)-2-O-benzoyl-5-O-levulinyl-α-L-arabinofuranosyl benzoate (15):

[0180]

[0181] A solution of S8 (S8 reference: Zhang Y, Chen Z, Huang Y, He S, Yang X, Wu Z, Wang X, Xiao G. Modular Synthesis of Nona-Decasaccharide Motif from Psidium guajava Polysaccharides: Orthogonal One-Pot Glycosylation Strategy. Angew Chem Int Ed Engl. 2020, 59, 7576-7584. prepared) (1.07 g, 1.95 mmol) and o-(1-phenylene) benzoic acid (484 mg, 2.14 mmol) in dry DCM (9.8 ml) was added to DMAP (238 mg, 1.95 mmol), EDCI (433 mg, 3.50 mmol) and DIPEA (1.02 ml, 5.84 mmol). The resulting mixture was stirred at room temperature for 10 hours. After the reaction was completed, it was concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 30:1-10:1) gave the intermediate (1.42 g, 96%, α / β 3:1). The above intermediate (1.00 g, 1.32 mmol, αisomer) was then dissolved in MeOH / DCM (13.2 ml, v / v 1 / 1), cooled to 0°C, and then AcCl (0.94 ml, 13.2 mmol) was added dropwise. After stirring at 0°C for 5 hours, the reaction mixture was quenched with saturated NaHCO3 solution, extracted with DCM 3 times, the organic layers were combined, washed with saturated brine, dried over anhydrous Na2SO4, filtered, and concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 4 / 1) gave the intermediate (692 mg, 87%). The above intermediate (692 mg, 1.15 mmol) and LevOH (200 mg, 1.72 mmol) were added to DMAP (142 mg, 1.15 mmol), EDCI (322 mg, 2.07 mmol) and DIPEA (0.60 ml, 3.45 mmol) in dry DCM (11.6 ml). The resulting mixture was stirred at room temperature for 10 hours. After the reaction was completed, it was concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 3 / 1) was performed to obtain the intermediate (803 mg, quant). Then the above intermediate (1.30 g, 1.86 mmol) was dissolved in DCM / H2O (18.7 ml, v / v 10 / 1) and DDQ (465 mg, 2.05 mmol) was added. The reactants were stirred at room temperature for 10 hours, diluted with ethyl acetate, and washed with saturated Na2S2O3 solution, water and saturated brine. Dry over anhydrous Na2SO4, filter and concentrate.Column chromatography (petroleum ether / ethyl acetate, 1:1) was used to separate and purify 15 (888 mg, 385%) as a colorless syrup. [α]. D 25 =-43.39(c0.13,CHCl3).1HNMR(400MHz,CDCl3)δ8.02(d,J=7.0Hz,2H),7.95(d,J=7.8Hz,1H),7.62 (t,J=7.5Hz,1H),7.58(t,J=7.5Hz,1H),7.48(t,J=7.3Hz,3H),7.37(d,J=7.6Hz,1H),7.33-7.16(m, 5H),6.30(s,1H,H-1),5.81(s,1H),5.26(s,1H),4.87(d,J=2.0Hz,1H),4.29(dd,J=12.1,3.5Hz,1H ),4.20(dd,J=12.0,4.8Hz,1H),4.07(m,2H),2.72(t,J=6.5Hz,2H),2.63-2.54(m,2H),2.15(s,3H). 13 C NMR (100MHz, CDCl3) δ205.8,171.7,165.9,165.4,148.1,142.0,139.2,133.1,131.5,130.6,129.6,129.1,127.8,1 27.6,127.1,127.0,125.8,113.5,99.1,85.1,81.5,76.6,76.3,76.2,75.9,62.1,37.1,29.0,27.0.HRMS(ESI)calcd for C 32 H 30 O9Na[M+Na] + 581.1782, found 581.1787.

[0182] The synthesis of hexasaccharide (27) is as follows:

[0183]

[0184] The PTFAI donor 17 (126 mg, 0.09 mmol), ABz acceptor 14 (14 Reference: Zhang Y, Chen Z, Huang Y, He S, Yang X, Wu Z, Wang X, Xiao G. Modular Synthesis of Nona-Decasaccharide Motiffrom Psidium guajava Polysaccharides: Orthogonal One-Pot Glycosylation Strategy. Angew Chem Int Ed Engl. 2020, 59, 7576-7584. Preparation) (46 mg, 0.09 mmol) and the newly activated MS (200 mg), (207 mg) in dry DCM (0.4 mL) was stirred at room temperature for 15 minutes and then cooled to -40 ° C. TMSOTf (4.0 μL, 0.02 mmol) was added dropwise to the mixture. After stirring for another 2 hours at -40 ° C, the reaction mixture was warmed to room temperature, and then PVB receptor 15 (41 mg, 0.07 mmol) was dissolved in dry DCM (0.2 mL) and freshly prepared PPh3AuOTf dissolved in DCM (0.1 mL, 0.12 M) was added. After stirring at room temperature for 2 hours, the reaction mixture was cooled to -78 ° C, and then the receptor 16 (16 reference: Zhang Y, Chen Z, Huang Y, He S, Yang X, Wu Z, Wang X, Xiao G. Modular Synthesis of Nona-Decasaccharide Motiffrom Psidium guajava Polysaccharides: Orthogonal One-Pot Glycosylation Strategy. Angew Chem Int Ed Engl. 2020, 59, 7576-7584. Preparation) (47 mg, 0.07 mmol), NIS (98 mg, 0.43 mmol) and TMSOTf (47 μL, 0.26 mmol) were added in sequence. The resulting mixture was stirred at -78 ° C for 3 h, then quenched with Et3N (1 mL) and filtered, concentrated, and purified by column chromatography (volume ratio of petroleum ether / ethyl acetate = 2: 1) to obtain colorless syrup 27 (78 mg, yield 45%). [α] D 25.0=-6.00(c 0.15,CHCl3).1H NMR(400MHz,CDCl3)δ7.95-7.80(m,14H),7.45(q,J=7.4Hz,4H),7.38-6.97(m,52H),5.50(s,2H),5.40(dd,J=12.0,5.5Hz,4H),5.22(d,J=14.4Hz,2H),5.14-4.98(m,3H),4.85(d,J=11.4Hz,3H),4.81-4.70(m,3H),4.65-4.52(m,6H),4.51-4.30(m,12H),4.28-4.19(m,3H),4.12(m,1H),4.04(m,1H),4.00-3.91(m,2H),3.85(d,J=9.9Hz,1H),3.81-3.53(m,6H),3.51-3.23(m,4H),3.10(m,2H),2.52-2.39(m,2H),2.34(m,2H),1.91(s,3H),1.51-1.32(m,4H),1.18(s,2H),0.86(d,J=5.5Hz,21H). 13C NMR (100MHz, CDCl3) δ205.3,171.4,165.2,165.2,164.7,164.5,164.4,164.3,138.2 ,137.9,137.4,137.3,137.2,137.0,132.5,132.44,132.35,132.3,132.0,129.1,129 .05,128.99,128.9,128.9,128.8,128.7,128.6,128.5,127.63,127.59,127.55,127.52,127.48,127.43,127.37,127.02,126.98,126.95,126.92,126.87,126.81,126.77 ,126.74,126.68,126.5,126.37,105.36,105.0,104.5,104.2,103.8,97.2,82.2,82.1,81.9,81.5,81.3,81.2,81.0,80.6,80.4,79.8,79.3,79.2,78.9,78.4,76.6,76.4 3,76.35,76.2,75.9,74.6,74.1,72.6,72.2,71.2,69.8,67.9,66.4,66.2,64.7,62.1 ,62.0,61.5,37.0,28.9,28.8,28.1,26.9,22.4,17.05,16.98,11.0.HRMS(ESI)calcd forC 149 H 159 NO 37 SiNa[M+Na] + 2605.0252, found 2605.0258.

[0185] 5) Synthesis of hexasaccharide (10), the reaction equation is as follows:

[0186]

[0187] 27 (175 mg, 0.07 mmol) was dissolved in MeOH / DCM (total volume 0.68 mL, volume ratio v / v = 1 / 1), cooled to -20 ° C, and AcCl (48 μL, 0.68 mmol) was added dropwise. The TIPS group in 27 was selectively removed with AcCl and MeOH. The reaction mixture was stirred for 48 hours, quenched with saturated NaHCO3 solution, and then extracted with DCM three times. The organic phase was washed with water and saturated brine, dried over anhydrous Na2SO4, filtered, and concentrated. Column chromatography was separated and purified (volume ratio of petroleum ether / ethyl acetate = 1 / 1) to obtain colorless syrup 10 (143 mg, yield 87%). [α] D 24.2 =-7.00 (c 0.08, CHCl3). 1 H NMR (400MHz, CDCl3) δ8.01-7.73 (m, 14H), 7.46 (t, J = 6.3Hz, 4H), 7.42-6.9 6(m,52H),5.52(s,2H),5.45-5.39(m,2H),5.37(d,J=2.3Hz,2H),5.24(s, 1H),5.19(d,J=1.9Hz,1H),5.13-5.01(m,3H),4.85(d,J=9.9Hz,2H),4.76 (dt,J=10.2,3.1Hz,3H),4.72(d,J=3.4Hz,1H),4.67-4.60(m,2H),4.59-4 .51(m,5H),4.51-4.41(m,4H),4.41-4.29(m,7H),4.28-4.12(m,5H),4.05 (dt,J=7.1,4.0Hz,1H),3.98-3.89(m,2H),3.83(d,J=10.0Hz,1H),3.64(m ,6H),3.43(m,3H),3.34-3.23(m,1H),3.17-2.99(m,2H),2.47(dd,J=8.4, 6.4Hz,2H),2.36(q,J=6.5Hz,2H),1.93(s,3H),1.43(s,4H),1.18(s,2H). 13C NMR (100MHz, CDCl3) δ206.4,172.5,166.4,166.2,165.6,165.55,165.48,16 5.43,165.3,139.0,138.7,138.3,138.3,138.1,137.9,133.5,133.45,133. 38,133.3,133.2,133.0,130.05,129.97,129.9,129.8,129.6,129.5,129.4,128.7,128.63,128.58,128.5,128.45,128.38,128.2,128.03,127.97,127. 9,127.8,127.7,127.6,127.6,127.3,106.3,106.0,105.3,105.1,105.0,98.3,83.2,82.9,82.5,82.2,81.9,81.6,81.0,80.8,80.7,80.2,80.0,77.6,7 7.4,77.2,76.9,75.7,75.0,73.7,73.5,72.3,71.0,69.0,67.34,67.2,65.7 ,63.0,62.1,51.0,37.9,29.8,29.8,29.1,28.0,27.8,23.4.HRMS(ESI)calcd for C 140 H 139 NO 37 Na[M+Na] + 2448.8918, found 2448.8921.

[0188] Synthesis of substructure 2: 6) 2-O-benzyl-3-O-levulinyl-4-O-benzoyl-N-trifluoroacetimidate-D-pyranose (12)

[0189]

[0190] 24o (24o Reference: Zhou J, Yang L, Hu W. Stereoselective Synthesis of a Sulfated Tetrasaccharide Corresponding to a Rare Sequence in the Galactofucan Isolated from Sargassum polycystum. J Org Chem. 2014, 79, 4718-4726. Preparation) (1.18 g, 2.54 mmol) and LevOH (443 mg, 3.82 mmol) were dissolved in dry DCM (25 ml), and DMAP (311 mg, 2.54 mmol), EDCI (711 mg, 4.58 mmol) and DIPEA (1.30 ml, 7.63 mmol) were added. Stir at room temperature for 10 hours. After the reaction was completed, concentrate. Column chromatography separation and purification (petroleum ether / ethyl acetate, 2 / 1) gave the intermediate (1.38 g, 97%). The above intermediate (1.38 g, 2.46 mmol) was dissolved in acetone / H2O (61 ml, v / v 4 / 1), cooled to 0°C, and TCCA (571 mg, 2.46 mmol) was added and stirred at room temperature for 4 hours. The solution was diluted with ethyl acetate, washed with saturated NaHCO3, water and brine, dried over anhydrous Na2SO4, filtered and concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 1 / 1) gave the hemiacetal intermediate (1.03 mg, 92%). The above intermediate (1.03 g, 2.26 mmol) was dissolved in acetone (23 ml), and then 2,2,2-trifluoro-N-phenylacetimidoyl chloride (842 mg, 4.07 mmol) and anhydrous potassium carbonate (570 mg, 4.07 mmol) were added. The mixture was stirred at room temperature for 10 hours. After the reaction was completed, the reaction mixture was filtered and concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 60 / 1, containing 3% Et3N) gave colorless syrup 12 (1.42 g, quant, β / α = 1.7 / 1). 1HNMR(400MHz, CDCl3)δ8.13(d,J=7.7Hz,3H),8.06(d,J=7.8Hz,2H),7.70-7.63(m,3H),7.53(m,6H),7. 41-7.27(m,19H),7.15(q,J=7.1Hz,3H),6.89(d,J=7.8Hz,3H),6.81(d,J=7.7Hz,2H),5.63(s,1H),5.53 (d,J=3.4Hz,1H),5.51-5.46(m,2H),5.16(s,2H),4.86(d,J=11.2Hz,2H),4.75(t,J=5.6Hz,4H),4.44(s ,1H),4.18-4.10(m,1H),3.99(t,J=9.3Hz,2H),2.85-2.37(m,13H),2.12(d,J=8.0Hz,8H),1.27(m,8H). 13 CNMR(100MHz, CDCl3)δ205.3,205.1,171.0,170.9,165.12,165.06,142.7,142.5,136.7,132. 7,132.6,129.0,128.9,128.5,128.4,127.90,127.86,127.8,127.6,127.5,127.3,127.10,12 7.08,126.99,123.5,123.4,118.6,118.4,76.6,76.2,75.9,74.5,74.2,72.4,72.2,71.6,70. 6,70.0,69.5,69.4,66.8,37.0,36.9,28.80,28.76,27.1,27.0,15.24,15.19.HRMS(ESI)calcd for C 33 H 32 F3NO8Na[M+Na]+650.1972,found 650.1974.

[0191] 7) Synthesis of disaccharide (29), the reaction equation is as follows:

[0192]

[0193] PTFAI donor 12 (456 mg, 0.67 mmol) and acceptor 11 (i.e., formula 24o) (225 mg, 0.45 mmol) and Ph3P=O (1.12 g, 4.03 mmol) were dissolved in dry DCM (6.7 mL) and added under argon protection at room temperature. Molecular sieves (701 mg), stirred for 15 minutes. Then TMSI (95 μL, 0.67 mmol) was added dropwise. The reaction was stirred at room temperature for 48 h. After the reaction was completed, the solution was diluted with ethyl acetate, the reaction was quenched with saturated Na2S2O3 (direct separation after quenching), the organic phase was washed with water and saturated brine in turn, dried over anhydrous Na2SO4, filtered and concentrated. Column chromatography separation and purification (volume ratio of petroleum ether / ethyl acetate = 4 / 1) gave colorless syrup 28 (429 mg, yield 98%). 28 (429 mg, 0.48 mmol) was dissolved in pyridine / AcOH (total volume 4.7 mL, v / v = 3 / 2) and NH2NH2·H2O (69 μL, 1.43 mmol) was slowly added. After stirring at room temperature overnight, the reaction was quenched with acetone, concentrated, and then the mixture was diluted with ethyl acetate, and washed with 4M HCl, saturated NaHCO3 solution and saturated brine in turn, dried over anhydrous Na2SO4, filtered and concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 3 / 1) gave 29 (377 mg, yield 99%). D 25.1 =-109.50 (c 0.24, CHCl3). 1 HNMR (400MHz, CDCl3) δ8.02(d,J=7.0Hz,2H),7.90(d,J=7.0Hz,2H),7.64(d,J=8.1Hz,2H),7.57(dt,J=21.3,6.8Hz,2H),7.46-7.29( m,9H),7.24-7.16(m,5H),7.12(dd,J=6.7,2.7Hz,2H),5.71(d,J=3.2Hz,1H),5.43(d,J=3.4Hz,1H,1-H),5.07(d,J=10.4Hz,1H),5.03 (d,J=3.3Hz,1H),4.68(d,J=9.5Hz,1H,2-H),4.58(d,J=10.4Hz,1H),4.53(d,J=12.0Hz,1H),4.35(d,J=12.0Hz,1H),4.18(q,J=6.5H z,1H),4.15-4.04(m,2H),3.92-3.81(m,2H),3.75(dd,J=10.1,3.3Hz,1H),2.43(s,3H),1.32(d,J=6.3Hz,3H),0.91(d,J=6.4Hz,3H). 13C NMR (100MHz, CDCl3) δ166.50,166.47,138.2,138.1,137.64,133.62,133.5,13 3.1,130.3,129.97,129.91,129.89,129.4,129.1,128.7,128.6,128.5,128.4, 128.25,128.17,127.94,127.88,92.0,87.3,77.6,77.2,76.9,75.79,75.75,75 .4,75.2,73.6,73.5,72.0,68.7,67.9,65.2,21.4,17.1,16.0.HRMS(ESI)calcd for C 47 H 48 O 10 SNa[M+Na] + 827.2860, found827.2869.

[0194] 8) Synthesis of trisaccharide (9), the reaction equation is as follows:

[0195]

[0196] PTFAI donor 21d (445 mg, 0.70 mmol) and acceptor 29 (377 mg, 0.47 mmol) were dissolved in dry DCM (7.0 mL) with Ph3P=O (1.17 g, 4.22 mmol) and freshly activated Molecular sieves (879 mg), stirred for 15 minutes. Then TMSI (67 μL, 0.47 mmol) was added dropwise. The reaction was stirred at room temperature for 96 hours. After the reaction was completed, the solution was diluted with ethyl acetate, and the reaction was quenched with saturated Na2S2O3 solution (direct separation after quenching). The organic phase was washed with water and saturated brine in turn, dried over anhydrous Na2SO4, filtered and concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate = 3 / 1) gave white foam 30 (546 mg, yield 94%). 30 (233 mg, 0.19 mmol) was dissolved in acetone / H2O (total volume 4.6 mL, v / v 4 / 1), cooled to 0°C, TCCA (43 mg, 0.19 mmol) was added, and stirred at room temperature for 10 hours. The solution was diluted with ethyl acetate, washed with saturated NaHCO3 solution, water and saturated brine in turn, dried over anhydrous Na2SO4, filtered and concentrated. Column chromatography separation and purification (volume ratio of petroleum ether / ethyl acetate = 2 / 1) gave a hemiacetal intermediate (193 mg, 90%). The above intermediate (84 mg, 0.07 mmol) was dissolved in acetone (0.7 mL), and then 2,2,2-trifluoro-N-phenylacetimidoyl chloride (27 mg, 0.13 mmol) and anhydrous potassium carbonate (18 mg, 0.13 mmol) were added. The mixture was stirred at room temperature for 10 hours. After the reaction was completed, it was concentrated. Column chromatography separation and purification (volume ratio of petroleum ether / ethyl acetate = 60 / 1, containing 3% Et3N) gave a colorless syrup 9 (96 mg, quant (quantitative yield, 100%), β / α = 1.7 / 1). 1HNMR(400MHz,CDCl3)δ8.17(d,J=7.7Hz,4H),8.07(d,J=7.7Hz,2H),8.02-7.97(m,2H),7.94(d,J=7.7Hz,4H),7.87(t,J=7.5Hz,5H),7.72-7.55(m,12H),7.55-7.30(m,40H),7.24(m,18H),7.19-7.12(m,6H),7.12-7.02(m,11H),6.93(d,J=7.9Hz,3H),6.87(d,J=7.7Hz,2H),5.88-5.78(m,2H),5.72(s,2H),5.65(m,3H),5.51(m,2H),5.43(d,J=3.5Hz,2H),5.39(d,J=3.2Hz,2H),5.36(d,J=3.5Hz,2H),5.34(d,J=3.5Hz,1H),5.19(dd,J=7.6,3.5Hz,3H),5.03(d,J=10.4Hz,2H),4.86(m,4H),4.72(t,J=10.3Hz,3H),4.61-4.51(m,4H),4.47-4.31(m,12H),4.29(s,1H),4.24(t,J=6.7Hz,3H),4.17-3.99(m,9H),1.30(m,9H),1.10(d,J=6.4Hz,3H),0.97(d,J=6.4Hz,5H),0.85(d,J=6.4Hz,5H),0.76(d,J=6.4Hz,3H). 13C NMR (100MHz, CDCl3) δ166.70,166.68,166.5,166.3,166.2,166.1,165.41,165.3 7,143.7,138.0,137.9,137.8,137.74,133.66,133.59,133.23,133.19,132.9,13 0.3,130.2,130.1,130.04,129.95,129.88,129.86,129.83,129.8,129.7,129.5,129.0,128.9,128.82,128.78,128.76,128.6,128.54,128.50,128.48,128.44,12 8.39,128.22,128.19,128.17,128.12,128.06,127.8,127.7,127.4,124.5,119.5,93.6,93.1,92.7,92.5,77.6,77.4,77.2,77.1,76.9,76.1,74.3,74.1,73.7,73. 5,73.2,72.7,72.3,72.2,71.85,71.82,70.9,70.5,70.4,70.3,70.2,69.6,69.5, 68.7,68.6,65.3,64.7,64.6,29.9,16.6,16.3,16.1,16.0,15.9.HRMS(ESI)calcd for C 75 H 70 F3NO 17 Na[M+Na] + 1336.4488, found 1336.4495.

[0197] 9) Synthesis of nonasaccharide (31), the reaction equation is as follows:

[0198]

[0199] The PTFAI donor 9 (206 mg, 0.16 mmol) and the acceptor 10 (254 mg, 0.11 mmol) were dissolved in dry DCM (1.6 mL) and freshly activated MS (500 mg) was added and stirred for 15 minutes. TMSI (22 μL, 0.16 mmol) was then added dropwise. The reaction was stirred at room temperature for 38 h. After the reaction was completed, the solution was diluted with ethyl acetate and quenched with saturated Na2S2O3 (direct separation after quenching). The organic phase was washed with water and saturated brine in turn, dried over anhydrous Na2SO4, filtered, and concentrated. Column chromatography was used for separation and purification (volume ratio of petroleum ether / ethyl acetate = 1.2 / 1) to obtain white foam 31 (353 mg, yield 95%). [α] D 25.0 =-87.34 (c 0.09, CHCl3). 1 HNMR(400MHz, CDCl3)δ8.10-7.80(m,22H),7.71-7.63(m,2H),7.61-7.50(m,6H),7.50-7.11(m,70 H),7.10-7.00(m,5H),5.62(dt,J=12.4,3.7Hz,5H),5.56(d,J=3.1Hz,1H),5.50(s,1H),5.48(d,J =1.8Hz,1H),5.38(d,J=3.3Hz,1H),5.35(s,1H),5.33(d,J=3.6Hz,1H,1-H),5.29(s,1H),5.27(d, J=3.6Hz,1H,2-H),5.16(q,J=7.2Hz,3H),5.07(d,J=3.5Hz,1H,3-H),4.97(dd,J=7.2,3.7Hz,1H), 4.94(s,1H),4.92-4.81(m,3H),4.78-4.57(m,12H),4.57-4.50(m,3H),4.50-4.27(m,20H),4.06( q,J=3.8Hz,3H),4.04-3.95(m,5H),3.82(d,J=10.6Hz,3H),3.78-3.70(m,1H),3.58(dd,J=9.7,3. 5Hz,1H),3.48-3.35(m,3H),3.21(m,2H),2.62-2.50(m,2H),2.44(q,J=7.0Hz,2H),2.01(s,3H),1 .64-1.45(m,4H),1.30(m,2H),1.07(d,J=6.4Hz,3H),0.92(d,J=6.4Hz,3H),0.69(d,J=6.4Hz,3H). 13C NMR (100MHz, CDCl3) δ206.2,172.3,166.5,166.2,166.13,166.09,166.0,165.6,165.4,165.31,165.28,165. 2,139.0,138.7,138.5,138.2,138.1,138.0,137.92,137.88,136.9,133.3,133.2,133.1,133.0,132.9,132.7 ,130.03,129.97,129.94,129.90,129.87,129.85,129.80,129.7,129.6,129.6,129.5,129.4,128.5,128.5,128.42,128.39,128.34,128.32,128.29,128.25,128.23,128.1,128.03,128.00,127.95,127.90,127.86,127. 83,127.75,127.63,127.61,127.5,127.43,127.39,127.3,106.3,105.9,105.4,105.0,98.8,98.1,93.2,92.4,82.82,82.76,82.6,82.1,81.8,81.5,80.8,80.6,80.3,80.1,79.9,77.4,77.3,77.1,76.8,75.5,75.0,74.2 ,73.9,73.4,72.9,72.83,72.80,72.7,72.2,72.1,71.6,71.0,70.8,70.3,70.2,69.6,68.6,67.2,67.1,65.9, 65.8,65.3,65.0,64.4,63.0,62.8,37.8,29.7,29.7,28.9,27.7,23.3,16.4,16.2,15.7.MS(MALDI-TOF)calcd forC 207 H 203 NO 53 Na[M+Na] + 3473.3113, found 3473.3112.

[0200] 10) Synthesis of nonasaccharide (2), the reaction equation is as follows:

[0201]

[0202] 31 (104 mg, 0.030 mmol) was dissolved in MeOH / DCM (total volume 3 mL, v / v = 1:1) and NaOMe was added to adjust the pH to 11. After stirring at room temperature for 7 days, the reaction was neutralized with 4M HCl to pH = 7, then filtered and concentrated. The intermediate (83 mg, 80%) was separated and purified using Sephadex TM LH20 (volume ratio MeOH / DCM = 1:1). The above intermediate (83 mg, 0.024 mmol) and Pd / C (128 mg, 10%) were dissolved in MeOH / H2O / HOAc (4 mL / 0.5 mL / 0.01 mL), stirred at room temperature for 10 h under H2 atmosphere, then filtered and concentrated. The white solid 2 (27.3 mg, yield 82%) was separated and purified using Sephadex TM LH-20 (volume ratio MeOH / H2O = 1 / 1). [α] D 25.1 =-2.92 (c 0.41, H2O). 1 H NMR(600MHz,D2O)δ5.12(s,1H),5.10(s,1H),5.09(s,1H),5.02(d,J=3.8Hz,1H),4.98(d,J=4.0Hz,1H),4.96(d d,J=4.2,1.7Hz,2H),4.93-4.89(m,2H),4.27(dd,J=11.3,3.8Hz,3H),4.23(s,1H),4.22-4.19(m,1H),4.18(dd ,J=2.7,1.3Hz,1H),4.14(t,J=2.2Hz,1H),4.08-3.93(m,12H),3.93-3.81(m,8H),3.81-3.61(m,12H),3.60-3. 46(m,4H),3.42(t,J=9.5Hz,1H),2.92(t,J=7.6Hz,2H),1.60(m,4H),1.38(q,J=8.1Hz,2H),1.20-1.11(m,9H). 13C NMR(150MHz,D2O)δ107.9,107.2,107.0,106.9,99.3,98.6,95.6,95.2,84.5,83.5,82.62,8 2.56,82.41,81.40,81.39,81.0,79.9,79.5,79.2,79.18,76.24,74.8,74.4,72.8,71.8,71 .13,71.10,69.4,69.3,68.4,68.2,68.0,67.8,67.7,66.9,66.8,66.6,66.54,66.50,66.4, 66.2,60.9,60.88,60.75,39.3,28.0,26.4,23.2,22.2,15.43,15.38,15.2.HRMS(ESI)calcd forC 54 H 93 NO 38 H[M+H] + 1386.5268, found 1386.5264.

[0203] Example 6: Synthesis of 13 sugars 1) Disaccharide (7)

[0204]

[0205] S10 (S10 reference: Zhang Y, Chen Z, Huang Y, He S, Yang X, Wu Z, Wang X, Xiao G. Modular Synthesis of Nona-Decasaccharide Motif from Psidium guajava Polysaccharides: Orthogonal One-Pot Glycosylation Strategy. Angew Chem Int Ed Engl. 2020, 59, 7576-7584.) (1.99 g, 2.13 mmol) was dissolved in Toluene / MeCN / H2O (42 ml, v / v / v 3 / 5 / 3), cooled to 0°C, and then CAN (2.67 g, 4.86 mmol) was added. After stirring at 0°C for 2 hours, the solution was quenched with saturated NaHCO3 solution, extracted 3 times with DCM, and the organic phase was washed with saturated brine, dried over Na2SO4, filtered, and concentrated. Column chromatography separation and purification (petroleum ether / ethyl acetate, 5 / 1) gave a light yellow syrup intermediate (1.64 g). The above intermediate (1.64 g) and PVBOH (666 mg, 2.98 mmol) were dissolved in dry DCM (9.9 ml), and DMAP (242 mg, 1.98 mmol), EDCI (554 mg, 3.57 mmol) and DIPEA (1.04 ml, 5.95 mmol) were added. The resulting mixture was stirred at room temperature for 10 h. After completion, the solvent was evaporated under vacuum. Column chromatography separation and purification (petroleum ether / ethyl acetate, 15 / 1) gave an intermediate (1.84 g, 83%, 2 steps, α / β1.5:1). The above intermediate (324 mg, 0.31 mmol, α isomer) was then dissolved in MeOH / DCM (3.2 ml, v / v 3 / 1), cooled to 0 ° C, and then AcCl (0.22 ml, 3.14 mmol) was added dropwise. After stirring at 0°C for 9 h, the reaction was quenched with saturated NaHCO3 solution and extracted three times with CH2Cl2. The organic phase was washed with saturated brine, dried over anhydrous Na2SO4, filtered and concentrated. Column chromatography (petroleum ether / ethyl acetate, 2 / 1) was used to separate and purify 7 (233 mg, 85%). [α] D 25 =-91.69 (c 0.52, CHCl3). 1HNMR(400MHz, CDCl3)δ8.14-8.04(m,4H),8.03-7.98(m,1H),7.65-7.56(m,3H),7.51-7.22(m,22H),6.34(s,1H), 5.83(s,1H),5.52-5.47(m,1H),5.42(d,J=1.4Hz,1H),5.32(s,1H),5.29(s,1H),4.86(d,J=11.9Hz,1H),4.68(d,J =12.0Hz,2H),4.52(d,J=12.1Hz,1H),4.39(q,J=4.5Hz,1H),4.28(d,J=4.9Hz,1H),4.20-4.14(m,1H),4.05(d,J= 5.5Hz,1H),3.94(dd,J=11.4,4.2Hz,1H),3.84(dt,J=12.2,3.5Hz,1H),3.75(dd,J=11.4,4.5Hz,1H),3.64(m,1H). 13 C NMR (100MHz, CDCl3) δ166.0,165.3,165.2,149.0,143.2,140.4,137.8,137.6,133.54,1 33.50,132.0,131.3,130.5,130.3,129.9,129.8,129.4,129.2,128.62,128.56,128.4,1 28.2,127.82,127.80,127.77,127.75,127.66,127.63,126.9,114.5,106.4,100.5,84.1 ,83.5,83.0,82.9,81.8,81.0,77.5,77.2,76.9,72.3,72.2,65.7,61.9.HRMS(ESI)calcd for C 53 H 48 O 12 Na[M+Na] + 899.3038, found899.3039.

[0206] 2) Synthesis of nonasaccharide (8), the reaction equation is as follows:

[0207]

[0208] 31 (344 mg, 0.97 mmol) was dissolved in pyridine / AcOH (total volume 1.0 mL, v / v 3 / 2), and NH2NH2·H2O (14 μL, 0.29 mmol) was slowly added. The Lev group in 31 was selectively deprotected with NH2NH2-H2O. The mixture was stirred overnight at room temperature, quenched with acetone, concentrated, and then diluted with ethyl acetate and washed with 4M HCl, saturated NaHCO3 solution, and saturated brine in sequence. The mixture was dried over anhydrous Na2SO4, filtered, and concentrated. Column chromatography (petroleum ether / ethyl acetate, 1 / 1) gave 8 (333 mg, yield 97%). [α] D 25.3 =-34.43 (c 0.14, CHCl3). 1 H NMR (400MHz, CDCl3) δ8.13-7.77(m,22H),7.66(d,J=7.8Hz,2H),7.60-7.02(m,81H),5 .66-5.54(m,6H),5.52-5.44(m,2H),5.38(d,J=3.3Hz,1H),5.36-5.31(m,2H),5.29(d, J=1.7Hz,1H),5.26(d,J=3.6Hz,1H),5.22-5.11(m,4H),5.07(d,J=3.5Hz,1H),4.96(d ,J=9.5Hz,2H),4.93(d,J=3.4Hz,1H),4.89(d,J=11.2Hz,1H),4.84(d,J=10.8Hz,1H),4 .79(dd,J=12.6,2.6Hz,1H),4.70(q,J=6.3Hz,7H),4.66-4.58(m,4H),4.53(dd,J=6.5 ,3.4Hz,3H),4.49-4.25(m,16H),4.12(q,J=4.4Hz,1H),4.08-3.95(m,7H),3.91-3.68( m,8H),3.57(dd,J=9.6,3.6Hz,1H),3.45(dq,J=11.2,5.8Hz,3H),3.21(m,2H),1.54(s ,4H),1.29(s,2H),1.07(d,J=6.5Hz,3H),0.91(d,J=6.4Hz,3H),0.68(d,J=6.4Hz,3H). 13C NMR (101MHz, CDCl3) δ166.6,166.3,166.3,166.1,165.7,165.54,165.51,165.46,165.4,165.3,13 9.1,138.7,138.5,138.3,138.1,138.1,138.05,138.00,133.4,133.3,133.2,133.0,132.8,130.2 ,130.11,130.08,130.04,130.01,129.98,129.95,129.91,129.88,129.8,129.7,129.6,129.5,128.7,128.7,128.6,128.6,128.53,128.47,128.44,128.41,128.21,128.17,128.15,128.1,128.0, 127.85,127.79,127.76,127.7,127.4,106.5,106.0,105.4,105.0,104.8,98.6,98.2,93.3,92.5,83.2,83.0,82.9,82.6,82.5,82.3,82.2,81.9,81.7,81.3,80.8,80.2,77.6,77.4,77.2,76.9,75. 6,75.23,74.21,74.0,73.5,73.1,73.0,72.7,72.2,71.8,71.0,70.5,70.3,69.8,68.8,67.4,67.3 ,65.5,65.2,64.5,63.4,63.1,61.8,29.9,29.1,28.0,23.4,16.5,16.3,15.8.MS(MALDI-TOF)calcd for C 202 H 197 NO 51 Na[M+Na] + 3475.2745, found 3475.2743.

[0209] 3) Synthesis of tridecasaccharide (35), the reaction equation is as follows:

[0210]

[0211] PTFAI donor 5 (5 reference: B. Yu and H. Tao, Glycosyl Trifluoroacetimidates. 2. Synthesis of Dioscin and Xiebai Saponin IJ Org. Chem. 2002, 67, 9099-9102. Preparation) (29 mg, 0.04 mmol), ABz acceptor 6 (6 reference: Yang R, Sun X, Zhang Y, et al. The total synthesis of rhynchosporosides via orthogonal one-pot glycosylation and stereoselective a-glycosylation strategies. Organic & Biomolecular Chemistry, 2022, 20, 6755-6758. Preparation) (24 mg, 0.04 mmol) and activated MS (151 mg) and MS (173 mg) was stirred in dry DCM (0.4 mL) at room temperature for 15 minutes and then cooled to -40 ° C. TfOH (1.0 μL, 0.01 mmol) was added dropwise to the mixture. After stirring for another 2 hours at -40 ° C, the reaction mixture was warmed to room temperature, and then PVB acceptor 7 (33 mg, 0.04 mmol) dissolved in dry DCM (0.2 mL) and freshly prepared PPh3AuOTf (0.1 mL, 0.05 M in CH2Cl2) were added in sequence. After stirring for 2 hours at room temperature, the reaction mixture was cooled to 0 ° C, and then acceptor 8 (104 mg, 0.3 mmol), NIS (10 mg, 0.05 mmol) and TfOH (1.0 μL, 0.01 mmol) were added in sequence. The resulting mixture was stirred for 2 hours, then quenched with Et3N (1 mL), filtered and concentrated. (volume ratio of petroleum ether / ethyl acetate = 2 / 1) to obtain colorless syrup 35 (118 mg, yield 74%). D 25.3 =-72.75 (c 0.08, CHCl3). 1HNMR(400MHz,CDCl3)δ7.94(m,36H),7.69(d,J=7.8Hz,2H),7.64-6.93(m,122H),5.75(t,J=9.6Hz,1H),5.68-5.52(m,9H),5.49(s,1H),5.37(dd,J=11.7,3.6Hz,4H),5.30(d,J=5.2Hz,2H),5.25(d,J=7.5Hz,2H),5.19(dd,J=10.3,6.7Hz,4H),5.11(d,J=3.6Hz,1H),5.02(d,J=3.5Hz,1H),4.91(m,8H),4.79-4.58(m,14H),4.56-4.16(m,28H),4.13-3.68(m,24H),3.63-3.56(m,2H),3.52(t,J=8.4Hz,2H),3.42(d,J=10.6Hz,4H),3.21(m,3H),1.65-1.44(m,4H),1.31(s,2H),1.08(d,J=6.3Hz,3H),0.93(d,J=6.3Hz,3H),0.73(d,J=6.4Hz,3H). 13C NMR (100MHz, CDCl3) δ166.6,166.4,166.23,166.18,166.1,165.9,165.7,165.6,165.41,165.39,165.34,165.29,165.2,165. 1,165.0,139.11,138.9,138.7,138.4,138.2,138.1,138.1,138.05,138.03,137.97,137.0,133.6,133.4,133.3,133.2,133. 0,132.8,130.2,130.1,130.02,129.98,129.92,129.86,129.83,129.74,129.69,129.66,129.63,129.58,129.1,129.0,128.9,128.7,128.6,128.6,128.53,128.48,128.4,128.32,128.26,128.21,128.15,128.13,128.06,128.02,127.97,127.94,127. 87,127.8,127.74,127.68,127.62,127.58,127.5,127.44,127.39,127.35,106.38,106.0,105.1,105.0,101.4,100.6,99.0,98.2,93.3,92.5,83.4,83.0,82.9,82.6,82.2,82.0,81.8,81.6,81.3,80.7,80.5,80.2,79.62,77.55,77.4,77.2,76.9,75.6, 75.0,74.9,74.6,74.4,74.1,73.1,73.5,73.2,72.9,72.8,72.7,72.4,72.3,72.2,71.9,71.7,71.0,70.7,70.4,70.3,69.9,6 9.8,68.7,67.9,67.6,67.3,65.4,65.1,64.7,64.5,63.0,32.1,29.9,29.0,28.0,23.4,16.5,16.3,15.8.MS(MALDI-TOF)calcd forC 301 H 285 NO 76 Na[M+Na] + 5151.8359,found5151.8358.

[0212] 4) Synthesis of tridecasaccharide (1), the reaction equation is as follows:

[0213]

[0214] 35 (75 mg, 0.015 mmol) was dissolved in MeOH / DCM (total volume 3 mL, v / v = 1:1), and NaOMe was added to adjust the pH to 11. After stirring at room temperature for 8 days, the reaction was neutralized with 4M HCl to pH = 7, then filtered and concentrated. The intermediate (43 mg, 95%) was separated and purified using Sephadex TM LH20 (volume ratio MeOH / DCM = 1:1). The above intermediate (43 mg, 0.014 mmol) and Pd / C (128 mg, 10%) were dissolved in MeOH / H2O / HOAc (4 mL / 0.5 mL / 0.01 mL), stirred at room temperature for 10 hours under H2 atmosphere, and then the reaction mixture was filtered and concentrated. 1 (22.5 mg, yield 87%) was separated and purified using Sephadex TM LH-20 (volume ratio MeOH / H2O = 1 / 1). [α] D 24.0 =-587.00 (c 0.12, H2O). 1 H NMR(600MHz,D2O)δ5.13(s,1H),5.11(s,1H),5.07(s,1H),5.04-5.00(m,3H),4.98(d,J=4.1Hz,1H), 4.96(m,2H),4.91(m,2H),4.46(d,J=8.0Hz,1H),4.42(d,J=8.1Hz,1H),4.29-4.11(m,11H),4.07-3. 91(m,14H),3.90-3.80(m,10H),3.80-3.60(m,12H),3.59-3.48(m,5H),3.48-3.37(m,3H),3.34(d,J =9.2Hz,1H),3.31-3.19(m,3H),2.92(t,J=7.6Hz,2H),1.60(m,4H),1.37(m,2H),1.21-1.09(m,9H). 13C NMR(150MHz,D2O)δ107.9,107.5,107.4,107.2,107.2,106.93,106.88,102.5,102.3,99.3,98.6,95.6,95.2,84.3,83.5,82 .6,82.5,82.4,82.2,82.0,81.5,81.39,81.35,81.2,81.0,80.8,80.7,78.0,79.4,79.25,79.16,78.6,76.7,76.6,76.2,75. 9,75.4,74.9,74.7,74.4,74.1,73.1,72.82,72.79,71.9,71.13,71.08,69.4,69.3,68.9,68.5,68.2,68.0,67.8,66.9,66.8 ,66.7,66.5,66.5,66.4,66.3,60.99,60.95,60.7,60.5,59.9,39.3,28.0,26.4,22.2,15.5,15.4,15.2.HRMS(ESI)calcdfor C 76 H 129 NO 56 H[M+H] + 1952.7350, found 1952.7340.

[0215] Activity test

[0216] The Cell Counting Kit-8 (CCK-8) method was used to determine the effects of the compounds 1 to 2 of the present invention (i.e., the compounds of the structures shown in Formulas 1 to 2 of the present invention) on the proliferation of different leukemia cells. The method is as follows: Cell culture and administration: Human chronic myeloid leukemia cells K562, mouse leukemia cells L1210, and human mononuclear cells THP-1 were cultured using freshly prepared RPMI 1640 culture medium (containing 10% FBS, 1% penicillin-streptomycin), and the constant temperature incubator conditions were 5% CO2, 37°C. The above cells in good condition were collected and centrifuged, the supernatant was discarded, and the cells were resuspended in new culture medium at 3×10 4 Cells were inoculated at a density of 100 μL / mL in a 96-well plate, with 100 μL of cell suspension in each well; no cells were added to the blank wells, only cell culture medium was added; drug treatment was added after 12 hours of culture. The control group was added with 100 μL / well of culture medium; the compound 1-2 administration group was added with 100 μL / well of drug-containing culture medium, so that the final drug concentration in each group was 0.003 mg / L, 0.01 mg / L, 0.03 mg / L, 0.1 mg / L, 0.3 mg / L, 1 mg / L, 3 mg / L, 10 mg / L, 30 mg / L; 6 replicate wells were set up in each group, and culture was continued for 48 hours.

[0217] Absorbance determination: After 48 hours of drug action, 10 μL CCK-8 was added to each well, and the absorbance value at a wavelength of 450 nm was detected by a microplate reader 2 hours later. Data processing: The effect of different concentrations of drug-containing culture fluid on the proliferation rate of leukemia cells was calculated, and the proliferation rate (%) = (OD value of the drug-treated well - OD value of the blank well) / (OD value of the control group - OD value of the blank well) × 100. Statistical analysis: The experimental data were expressed as mean ± standard deviation, and variance analysis was used to compare different groups. P < 0.05 indicated a significant difference. The specific data are statistically shown in Tables 1 and 2.

[0218] Table 1 Effects of Compounds 1-4 on K562 Cell Proliferation (mean ± standard deviation, n = 6)

[0219]

[0220] Note: * Compared with the control group, there is a significant difference (P<0.05).

[0221] As shown in Table 1, with the increase of drug concentration, the inhibitory effect of compounds 1 and 2 on K562 cell proliferation was significantly enhanced, and when the drug concentration was 30 mg / L, the proliferation rates of K562 cells treated with compounds 1 and 2 were 57.6±1.5% and 50.5±1.2%, respectively (P<0.05).

[0222] Table 2 Effects of Compounds 1 and 2 on the proliferation of L1210 and THP-1 cells (mean ± SD, n = 6)

[0223]

[0224] Note: * Compared with the control group, there is a significant difference (P<0.05).

[0225] The results in Table 2 show that the proliferation rates of L1210 cells and THP-1 cells decreased significantly with the increase in the concentration of compound 2. When the concentration reached 30 mg / L, the cell proliferation rates were 53.6±1.4% and 70.0±0.4%, respectively (P<0.05). Compound 1 also had a significant inhibitory effect on the activity of L1210 cells. When the concentration was 30 mg / L, the cell proliferation rate was 61.2±1.6% (P<0.05).

[0226] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A highly stereoselective 1,2-cis-fucosylation reaction promoter composition, characterized in that: The invention comprises iodotrimethylsilane and triphenylphosphine oxide; the molar ratio of iodotrimethylsilane to triphenylphosphine oxide is 1:(5-10).

2. A fucose PTFAI donor for a highly stereoselective 1,2-cis-fucosylation reaction, characterized in that: The O-3 and / or O-4 position of the fucose PTFAI donor is substituted with an acyl group.

3. Use of the promoter composition according to claim 1 or the fucose PTFAI donor according to claim 2 in a glycosidation reaction.

4. A method for highly stereoselective 1,2-cis-fucosylation reaction, comprising the following steps: A fucose PTFAI donor, an alcohol acceptor, a promoter composition, a water scavenger and a polar organic solvent are mixed to carry out a glycosylation reaction to obtain a glycosylated product having a 1,2-cis-fucosylated bond; the stereoselectivity of the glycosylated product is α / β>20:1; the promoter composition is the promoter composition according to claim 1; and the fucose PTFAI donor is the fucose PTFAI donor according to claim 2.

5. The method according to claim 4, characterized in that The fucose PTFAI donor includes a monosaccharide PTFAI donor or a polysaccharide PTFAI donor; the monosaccharide PTFAI donor has a structure shown in Formula 21; in Formula 21, R 2 -Bn; R 3 -Bz or -Lev; R 4 is -Bz; the polysaccharide PTFAI donor has a structure shown in Formula 9; The alcohol acceptor has a structure shown in Formula 22, Formula 24, Formula 29 or Formula 10; HO(CH2)5NBnCbz Formula 22; H-OR Formula 24; in Formula 24, -OR has a structure shown in Formula 24d, Formula 24m or Formula 24v; When the monosaccharide PTFAI donor has the structure shown in Formula 21, the alcohol acceptor has the structure shown in Formula 22, Formula 24 or Formula 29; when the polysaccharide PTFAI donor has the structure shown in Formula 9, the alcohol acceptor has the structure shown in Formula 10.

6. A 13-sugar repeating unit of Angelica polysaccharide APS-III and its substructure 9-sugar, characterized in that: The 13-sugar repeating unit of the Angelica polysaccharide APS-III has a structure shown in Formula 1, and the substructure 9-sugar has a structure shown in Formula 2:

7. A method for preparing the sugar of substructure 9 according to claim 6, comprising the following steps: Mixing a fucose PTFAI donor 12, a fucose acceptor 11, a first promoter composition, a first polar organic solvent and a first dehydrating agent, and performing a first glycosylation reaction to obtain a first glycosylation product disaccharide 28; removing the Lev protecting group from the first glycosylation product disaccharide 28 to obtain the disaccharide acceptor 29; The fucose PTFAI donor 21d is mixed with the disaccharide acceptor 29, the second promoter composition, the second polar organic solvent and the second water scavenger, and a second glycosidation reaction is performed to obtain a trisaccharide 30; The trisaccharide 30 is selectively deprotected from the protecting group STol to obtain a trisaccharide intermediate; the trisaccharide intermediate, 2,2,2-trifluoro-N-phenylacetylimidate chloride, a third polar organic solvent and a first carbonate are mixed to perform a first substitution reaction to obtain a trisaccharide PTFAI donor 9 having a PTFAI protecting group; The trisaccharide PTFAI donor 9, the hexasaccharide acceptor 10, the third promoter composition, the fourth polar organic solvent and the third water scavenger are mixed to perform a third glycosidation reaction to obtain the nonasaccharide 31; The Bz and Lev protecting groups in the nonasaccharide 31 are selectively removed, and the Bn and Cbz groups are hydrogenolyzed to obtain the substructure 9 sugar; the first promoter composition, the second promoter composition and the third promoter composition are the promoter compositions according to claim 1 or 2; The fucose PTFAI donor 12 has a structure shown in Formula 12; the fucose acceptor 11 has a structure shown in Formula 24o; the first glycosylation product disaccharide 28 has a structure shown in Formula 28; the disaccharide acceptor 29 has a structure shown in Formula 29; the fucose PTFAI donor 21d has a structure shown in Formula 21d; the trisaccharide 30 has a structure shown in Formula 30; the trisaccharide PTFAI donor 9 has a structure shown in Formula 9; the hexasaccharide 10 has a structure shown in Formula 10; the nonasaccharide 31 has a structure shown in Formula 31; The arabinose ABz receptor 14 has a structure shown in Formula 14; the arabinose PVB receptor 15 has a structure shown in Formula 15; the arabinose receptor 16 has a structure shown in Formula 16; 8. The preparation method according to claim 7, characterized in that: The preparation of the hexasaccharide receptor 10 comprises the following steps: The arabinose PTFAI donor 18, the glucose PVB acceptor 19, the first activator, the fourth water scavenger and the fifth polar organic solvent are mixed to perform a fourth glycosidation reaction to obtain a reaction solution containing α-Araf-(1→6)-Glc disaccharide; The reaction solution containing α-Araf-(1→6)-Glc disaccharide, arabinose receptor 20, a second activator, and N,N-dimethylformamide are mixed to perform a fifth glycosylation reaction to obtain trisaccharide 26; the protecting group MP of the trisaccharide 26 is removed to obtain a hemiacetal intermediate; the hemiacetal intermediate, a sixth polar organic solvent, 2,2,2-trifluoro-N-phenylacetylimidate chloride, and a second carbonate are mixed to perform a second substitution reaction to obtain a trisaccharide PTFAI donor 17; The trisaccharide PTFAI donor 17, the arabinose ABz acceptor 14, the fifth dehydrating agent, the seventh polar organic solvent and the third activator are mixed to perform a sixth glycosylation reaction to obtain a reaction solution containing a tetrasaccharide ABz intermediate; the reaction solution containing the tetrasaccharide ABz intermediate, the arabinose PVB acceptor 15 and the catalyst are mixed to perform a seventh glycosylation reaction to obtain a reaction solution containing a pentasaccharide intermediate; The reaction solution containing the pentasaccharide intermediate, the arabinose receptor 16, and the fourth activator are mixed to perform an eighth glycosylation reaction to obtain a hexasaccharide 27; the hexasaccharide 27 is subjected to selective removal of the TIPS protecting group to obtain the hexasaccharide 10; The arabinose PTFAI donor 18 has a structure shown in Formula 18; the glucose PVB acceptor 19 has a structure shown in Formula 19; the arabinose acceptor 20 has a structure shown in Formula 20; the trisaccharide 26 has a structure shown in Formula 26; the trisaccharide PTFAI donor 17 has a structure shown in Formula 17; 9. The method for preparing the 13-sugar repeating unit of Angelica polysaccharide APS-III according to claim 6 comprises the following steps: Obtain nonasaccharide 31 according to the preparation method of claim 7 or 8; remove the Lev protecting group of the nonasaccharide 31 to obtain nonasaccharide 8; mix the glucose PTFAI donor 5, the glucose ABZ acceptor 6, the dehydrating agent, the first polar organic solvent and the first activator, and perform a ninth glycosylation reaction to obtain a reaction solution containing a disaccharide ABz intermediate; mix the reaction solution containing the disaccharide ABz intermediate, the arabinose PVB acceptor 7 and the catalyst, and perform a tenth glycosylation reaction to obtain a reaction solution containing a tetrasaccharide PVB intermediate; mix the reaction solution containing the tetrasaccharide PVB intermediate, the nonasaccharide 8 and the second activator, and perform an eleventh glycosylation reaction to obtain a tridecasaccharide 35; The protecting group of the tridecanes 35 is removed to obtain the 13-sugar repeating unit of the Angelica polysaccharide APS-III; The nonasaccharide 8 has a structure shown in Formula 8; the glucose PTFAI donor 5 has a structure shown in Formula 5; the glucose ABZ acceptor 6 has a structure shown in Formula 6; the arabinose PVB acceptor 7 has a structure shown in Formula 7; the tridecasaccharide 35 has a structure shown in Formula 35; 10. Use of the 13-sugar repeating unit of Angelica polysaccharide APS-III and its substructure 9 sugar according to claim 6, or the substructure 9 sugar prepared by the preparation method according to any one of claims 7 to 8, or the 13-sugar repeating unit of Angelica polysaccharide APS-III prepared by the preparation method according to claim 9 in the preparation of drugs for inhibiting the proliferation of leukemia cells.

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