Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigens, methods of making and uses thereof

Abstract

The application discloses a Helicobacter pylori lipopolysaccharide related oligosaccharide antigen and a preparation method and application thereof, and relates to the technical field of organic synthesis.The application discloses a structural formula of the Helicobacter pylori lipopolysaccharide related oligosaccharide antigen, and also discloses a preparation method and application of the oligosaccharide antigen.The oligosaccharide antigen has a clear structure, high purity and uniform components, has no endotoxin toxicity of natural lipopolysaccharide, and is suitable for immunological research and development of a sugar binding vaccine.

Description

Technical Field

[0001] This invention relates to the field of organic synthesis technology, specifically to a Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen, its preparation method, and its application. Background Technology

[0002] Helicobacter pylori (H. pylori) is a Gram-negative bacterium that colonizes the human stomach and is a major pathogen causing chronic gastritis, peptic ulcers, and gastric cancer. Currently, antibiotic therapy faces significant challenges due to drug resistance, while vaccine development is an effective strategy for preventing and controlling Helicobacter pylori infection.

[0003] Lipopolysaccharide (LPS) is a key virulence factor and conserved antigen on the surface of Helicobacter pylori, making it a highly promising vaccine target. However, natural LPS suffers from microscopic heterogeneity and endotoxin toxicity. Recent studies have revealed that a nonaglycone fragment containing conserved hexasaccharides and trisaccharides in Helicobacter pylori LPS is crucial for bacterial colonization in the stomach. However, the minimal antigenic epitope of this target remains unclear, and its structure-activity relationship with immunogenicity needs further analysis. Therefore, obtaining structurally defined and homogeneous oligosaccharide fragments through chemical synthesis and screening for antigenic epitopes with good immunogenicity and specificity is of great significance for developing novel Helicobacter pylori glycoconjugate vaccines. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention aims to provide a Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen, its preparation method, and its application. This oligosaccharide antigen has a well-defined structure, high purity, and uniform composition, and is free from the endotoxin toxicity of natural lipopolysaccharides, making it suitable for use in immunological research and the development of sugar conjugate vaccines.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] Firstly, a Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen is provided, the structural formula of which is:

[0007] , , ,

[0008] or .

[0009] Secondly, the present invention also provides a method for preparing the above-mentioned Helicobacter pylori lipopolysaccharide-related oligosaccharide antigen, comprising the following steps: assembling multiple orthogonally protected monosaccharide building blocks through a glycosylation reaction to obtain a fully protected oligosaccharide backbone; wherein, for the construction of 1,2-cis-α-l-fucoside bonds and 1,2-cis-α-d-glucoside bonds, the stereospecific construction of 1,2-cis-α-l-fucoside bonds is achieved by utilizing the long-range participation effect of the acyl group at the O-4 position of the glycosyl donor. The stereospecific construction of 1,2-cis-α-d-glucosidic bonds was achieved by utilizing the long-range participation effect of the acyl group at the O-6 position of the glycosyl donor. For the 2,7-branched d-glycerol-d-mannohepose skeleton, the glycosylation sequence of "O-2 first, then O-7" was followed, and the reaction was carried out in an aromatic solvent. In the process of constructing the oligosaccharide skeleton, the functional group modification of the sugar chain structure with significant steric shielding effect, i.e., N-Troc→N-Ac, was carried out according to the principle of "functional group transformation operation first".

[0010] Furthermore, the preparation method of Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen specifically includes the following steps:

[0011] S1. The monosaccharide acceptor 6 and the trisaccharide thioglycoside donor 7 are activated by N-iodosuccinimide and trifluoromethanesulfonic acid and then subjected to glycosylation to obtain the tetrasaccharide backbone 8.

[0012] S2. Tetrasaccharide compound 9 was prepared by a one-pot method using a system containing zinc powder, acetic anhydride, acetic acid solution and saturated copper sulfate solution to obtain tetrasaccharide skeleton 8.

[0013] S3. The tetrasaccharide compound 9 was selectively deprotected by DDQ oxidation-hydrolysis to obtain the tetrasaccharide receptor 10.

[0014] S4. The tetrasaccharide acceptor 10 and the disaccharothioglycoside donor 11 were activated in toluene by NIS / TfOH to carry out a glycosylation reaction to obtain a fully protected hexasaccharide backbone 12.

[0015] S5. The fully protected hexasaccharide skeleton 12 is subjected to alkaline hydrolysis and catalytic hydrogenation for global deprotection to obtain the target hexasaccharide 1, i.e., compound 1.

[0016] The structural formula of monosaccharide receptor 6 is The structural formula of trisaccharoside donor 7 is as follows: The tetrasaccharide skeleton 8 structure is The structural formula of tetrasaccharide compound 9 is The structural formula of tetrasaccharide receptor 10 is The structural formula of diglucosinolate donor 11 is as follows: The fully protected hexasaccharide backbone 12 structure is as follows: .

[0017] Furthermore, the tetrasaccharide receptor 10 was subjected to global deprotection by sequential alkaline hydrolysis and catalytic hydrogenation to obtain the target tetrasaccharide compound 2, namely compound 2.

[0018] Further, in step S1, the trisaccharide glucosinolate donor 7 is replaced with the monosaccharide glucosinolate donor 13 and activated by NIS / TfOH to carry out a glycosylation reaction to obtain disaccharide 14. Steps S2-S5 are repeated to obtain the target tetrasaccharide 3, i.e., compound 3.

[0019] The structural formula of monosaccharide glucosinolate donor 13 is as follows: The structural formula of disaccharide 14 is .

[0020] Further, in step S1, the monosaccharide acceptor 18 and the disaccharide thioglycoside donor 11 are activated by NIS / TfOH to undergo a glycosylation reaction to obtain trisaccharide 19; then, the trisaccharide is globally deprotected by alkaline hydrolysis and catalytic hydrogenation to obtain the target trisaccharide 4, i.e., compound 4.

[0021] The structural formula of monosaccharide receptor 18 is as follows: The structural formula of trisaccharide 19 is .

[0022] Further, in step S1, the disaccharide PTFAI donor 20 and Linker acceptor 21 are activated by trimethyliodosilane and triphenylphosphine (TMSI / Ph3PO) to undergo a glycosylation reaction to obtain disaccharide 22; then, the disaccharide is globally deprotected by alkaline hydrolysis and catalytic hydrogenation to obtain the target disaccharide 5, i.e., compound 5.

[0023] The disaccharide PTFAI donor 20 has the following structural formula: The Linker receptor 21 structure is as follows: The structural formula of disaccharide 22 is .

[0024] Furthermore, in step S2, the tetrasaccharide compound 9 is prepared in a one-pot process using a zinc-copper couple / acetic anhydride / acetic acid / copper sulfate system; specifically, zinc powder, acetic anhydride, acetic acid solution and saturated copper sulfate solution are added to the reactants.

[0025] Furthermore, the reducing end of the Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen is modified with an aminopropyl linker.

[0026] Furthermore, the purity of the Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen is ≥95%.

[0027] Thirdly, the present invention also provides the application of the above-mentioned Helicobacter pylori lipopolysaccharide-related oligosaccharide antigen in the preparation of sugar chips for initial screening of Helicobacter pylori infection-related activities or in the preparation of vaccines using mucin.

[0028] The present invention has the following beneficial effects:

[0029] 1. The Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen provided by this invention has a well-defined structure, high purity, and uniform composition. It is free from the endotoxin toxicity of natural lipopolysaccharides and is suitable for use in immunological research and the development of sugar conjugate vaccines.

[0030] 2. The preparation method provided by this invention adopts a convergent glycosylation strategy, which achieves stereospecific construction of 1,2-cis-α-l-glycosidic bonds through the remote participation effect. It completes the efficient assembly of the branched heptose skeleton by adopting the "O-2 first, then O-7" sequence and aromatic solvents, and achieves the efficient conversion of N-Troc to N-Ac by using the zinc-copper one-pot method. It has high overall yield, good stereoselectivity and strong reproducibility, and is suitable for the synthesis of various structure-related oligosaccharide antigens.

[0031] 3. This invention reveals for the first time through sugar chip detection that trisaccharide, tetrasaccharide, and hexasaccharide compounds containing the core framework of α-d-Glcp-(1→4)-α-d-Galp-(1→7)-α-d,d-Hepp exhibit strong immunobinding activity and good specificity in the serum of Helicobacter pylori-infected patients. Among them, the tetrasaccharide compounds formed by introducing a 2,7-branched heptose structure on the basis of the core trisaccharide have further enhanced immunobinding activity.

[0032] 4. This invention elucidates the structure-activity relationship of lipopolysaccharide-related oligosaccharides in Helicobacter pylori, and confirms that the α-d-Glcp-(1→4)-α-d-Galp-(1→7)-α-d,d-Hepp glycan backbone and its 2,7-branched heptose structure are key immunodominant epitopes, providing new antigen targets for the development of Helicobacter pylori glycan conjugate vaccines. Attached Figure Description

[0033] Figure 1 The hydrogen spectrum of compound 1 obtained in Example 1;

[0034] Figure 2 The carbon spectrum of compound 1 obtained in Example 1;

[0035] Figure 3 The hydrogen spectrum of compound 2 obtained in Example 2;

[0036] Figure 4 The carbon spectrum of compound 2 obtained in Example 2;

[0037] Figure 5 The hydrogen spectrum of compound 3 obtained in Example 3;

[0038] Figure 6 The carbon spectrum of compound 3 obtained in Example 3;

[0039] Figure 7 The hydrogen spectrum of compound 4 obtained in Example 4;

[0040] Figure 8 The carbon spectrum of compound 4 obtained in Example 4;

[0041] Figure 9 The hydrogen spectrum of compound 5 obtained in Example 5;

[0042] Figure 10 The carbon spectrum of compound 5 obtained in Example 5;

[0043] Figure 11 The immunogenicity and specificity test results of each oligosaccharide fragment obtained in Examples 1-5 are as follows:

[0044] Figure 12 The results of immunogenicity and specificity testing of each oligosaccharide fragment obtained in Examples 1-5 are as follows: Detailed Implementation

[0045] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0046] Example 1:

[0047] A Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen, the structural formula of which is as follows:

[0048] .

[0049] Its preparation method includes the following steps:

[0050] S1. Construction of the tetrasaccharide backbone: Monosaccharide acceptor 6 (115 mg, 0.14 mmol) and trisaccharide thioglycoside donor 7 (325 mg, 0.21 mmol) were dissolved in dry xylene / toluene (10.5 mL, 2:1, v / v). Activated 4 Å molecular sieve (1.0 g) was added at room temperature. The reaction system was stirred at room temperature for 15 minutes under nitrogen atmosphere. Subsequently, the reaction system was placed in a -30°C cryogenic bath and stirred for 15 minutes. NIS (72 mg, 0.32 mmol) and TfOH (7.1 μL, 0.08 mmol) were added sequentially to the reaction system. The reaction temperature was slowly raised to 0°C. The reaction was carried out at ℃ for 1 hour; the receptor reaction was complete as monitored by TLC; triethylamine was slowly added dropwise to adjust the pH of the reaction system to neutral, and the mixture was filtered. The filtrate was diluted with ethyl acetate and extracted successively with saturated sodium thiosulfate solution and saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (petroleum ether / EtOAc, 3:1) to obtain colorless syrupy tetrasaccharide skeleton 8, i.e., compound 8 (337 mg, 0.15 mmol, 71%).

[0051] R f = 0.31 (petroleum ether / EtOAc = 2:1). = -53.0 (c 0.43, CHCl3); 1H NMR (400 MHz, CDCl3) δ 8.00 (d, J = 7.7 Hz, 2H), 7.90 (d, J = 7.5Hz, 2H), 7.82 – 7.67 (m, 6H), 7.59 – 7.50 (m, 2H), 7.47 – 7.39 (m, 10H), 7.38– 7.33 (m, 6H), 7.31 – 7.25 (m, 25H), 7.24 – 7.22 (m, 4H), 7.20 – 7.15 (m,2H), 7.14 – 7.08 (m, 6H), 7.04 – 6.98 (m, 2H), 6.03 – 5.85 (m, 1H), 5.64 (t,J = 2.4 Hz, 1H), 5.51 (dd, J = 8.8, 3.3 Hz, 1H), 5.48 (s, 1H), 5.40 (d, J =3.4 Hz, 1H), 5.37 (d, J = 1.9 Hz, 1H), 5.26 (s, 1H), 5.15 – 5.03 (m, 4H),4.98 (d, J = 12.1 Hz, 1H), 4.84 (d, J = 12.2 Hz, 1H), 4.78 – 4.69 (m, 5H),4.67 – 4.62 (m, 3H), 4.61 – 4.56 (m, 4H), 4.54 – 4.48 (m, 3H), 4.45 (d, J =12.1 Hz, 1H), 4.39 – 4.37 (m, 1H), 4.36 – 4.34 (m, 2H), 4.33 – 4.31 (m, 1H),4.30 – 4.27 (m, 1H), 4.27 – 4.24 (m, 1H), 4.13 (dd, J = 7.5, 3.9 Hz, 1H),4.01 – 3.91 (m, 4H), 3.89 – 3.81 (m, 2H), 3.80 – 3.67 (m, 6H), 3.66 – 3.62(m, 1H), 3.60 – 3.54 (m, 1H), 3.54 – 3.46 (m, 1H), 3.42 – 3.27 (m, 3H), 3.17– 3.09 (m, 1H), 1.73 – 1.66 (m, 2H), 0.61 (d, J = 6.4 Hz, 3H). 13C NMR (150MHz, CDCl3) δ 166.5, 165.0, 164.9, 156.7, 154.1, 139.2, 138.8, 138.6, 138.3,138.3, 138.0, 137.6, 137.1, 136.5, 135.9, 133.3, 133.2, 133.0, 132.9, 132.8,130.0, 129.9, 129.7, 129.6, 129.5, 129.3, 128.5, 128.5, 128.5, 128.4, 128.3,128.3, 128.3, 128.3, 128.3, 128.2, 128.2, 128.1, 128.1, 128.1, 128.0, 127.9,127.9, 127.8, 127.7, 127.7, 127.6, 127.6, 127.6, 127.6, 127.6, 127.5, 127.5,127.5, 127.5, 127.4, 127.4, 127.3, 127.3, 126.4, 126.4, 126.0, 125.8, 102.0,100.2, 99.3, 98.2, 97.6, 95.5, 80.3, 79.4, 78.5, 77.9, 75.9, 75.1, 75.0,74.3, 74.2, 73.9, 73.5, 73.2, 73.2, 73.2, 73.1, 73.0, 72.9, 72.8, 72.8, 72.7,72.4, 72.3, 72.3, 72.3, 71.7, 70.6, 68.7, 66.8, 66.4, 65.5, 64.6, 58.7, 38.2,29.6, 15.6. HRMS (ESI): m / z calcd for C 128 H 131 NCl3N2O 28 [M+NH4] + 2262.7985,found: 2262.7990.

[0052] One-pot conversion of S2, N-Troc to N-Ac: The tetrasaccharide backbone 8 (260 mg, 0.12 mmol) was dissolved in tetrahydrofuran (4.0 mL). Activated zinc powder (200 mg), acetic anhydride (4.0 mL), acetic acid (2.0 mL), and saturated copper sulfate solution (2.0 mL) were added sequentially at 0 °C. The reaction system was incubated at room temperature for 3 hours. TLC monitoring showed that the substrate reaction was complete. The mixture was filtered, and the filtrate was diluted with an appropriate amount of ethyl acetate and placed at 0 °C. The reaction was quenched by slow addition of saturated sodium bicarbonate solution. The mixture was extracted sequentially with saturated sodium bicarbonate solution and saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (DCM / CH3OH, 40:1) to obtain colorless syrupy tetrasaccharide compound 9, i.e., compound 9 (190 mg, 0.09 mmol, 76%).

[0053] R f = 0.57 (DCM / CH3OH = 20:1). = -56.0 (c 0.50, CHCl3); 1H NMR (400MHz, CDCl3) δ 8.01 (d, J = 8.6 Hz, 2H), 7.89 (d, J = 8.3 Hz, 2H), 7.80 – 7.75(m, 4H), 7.74 – 7.68 (m, 2H), 7.66 (s, 1H), 7.58 – 7.54 (m, 1H), 7.53 – 7.49(m, 1H), 7.46 – 7.40 (m, 9H), 7.37 – 7.32 (m, 5H), 7.32 – 7.27 (m, 25H), 7.24– 7.19 (m, 7H), 7.15 – 7.10 (m, 6H), 7.02 – 6.98 (m, 2H), 5.79 – 5.68 (m,1H), 5.62 – 5.59 (m, 1H), 5.52 (dd, J = 8.6, 3.2 Hz, 1H), 5.47 (s, 1H), 5.42(d, J = 3.3 Hz, 1H), 5.35 (d, J = 2.0 Hz, 1H), 5.28 – 5.20 (m, 2H), 5.12 –5.04 (m, 3H), 4.97 (d, J = 12.1 Hz, 1H), 4.88 – 4.82 (m, 1H), 4.82 – 4.76 (m,2H), 4.74 – 4.69 (m, 2H), 4.67 (d, J = 4.1 Hz, 1H), 4.65 – 4.62 (m, 2H), 4.62– 4.56 (m, 2H), 4.55 – 4.47 (m, 6H), 4.43 (d, J = 12.1 Hz, 1H), 4.39 – 4.33(m, 3H), 4.31 – 4.24 (m, 2H), 4.13 (dd, J = 7.1, 4.2 Hz, 1H), 4.02 (t, J =2.6 Hz, 1H), 4.00 – 3.96 (m, 2H), 3.91 – 3.80 (m, 3H), 3.77 – 3.65 (m, 6H),3.59 – 3.52 (m, 2H), 3.45 – 3.38 (m, 1H), 3.29 – 3.14 (m, 3H), 1.77 – 1.68(m, 2H), 1.60 (s, 3H), 0.58 (d, J = 6.4 Hz, 3H). 13C NMR (100 MHz, CDCl3) δ171.1, 166.5, 165.2, 165.1, 156.6, 139.3, 138.7, 138.7, 138.4, 138.3, 138.1,138.0, 137.3, 136.8, 135.9, 133.4, 133.3, 133.1, 133.0, 133.0, 130.1, 130.0,129.9, 129.8, 129.8, 129.7, 129.6, 129.4, 128.7, 128.6, 128.6, 128.5, 128.5,128.4, 128.4, 128.4, 128.3, 128.3, 128.2, 128.2, 128.2, 128.1, 128.1, 128.0,128.0, 128.0, 127.9, 127.8, 127.8, 127.8, 127.7, 127.7, 127.6, 127.6, 127.6,127.5, 127.4, 127.4, 126.5, 126.4, 126.1, 125.9, 125.8, 102.2, 99.6, 99.2,98.1, 98.1, 80.8, 79.6, 78.8, 78.0, 76.0, 75.5, 75.2, 74.9, 74.7, 74.6, 74.1,73.7, 73.4, 73.3, 73.3, 73.3, 73.1, 72.9, 72.6, 72.4, 72.4, 71.9, 71.8, 70.8,70.8, 68.8, 66.7, 66.5, 65.7, 65.0, 59.0, 38.3, 29.5, 23.4, 15.6. HRMS (ESI):m / z calcd for C 127 H 129 N2O 27 [M+H] + 2113.8783, found: 2113.8789.

[0054] Selective removal of S3 and Nap protecting groups: Tetrasaccharide compound 9 (160 mg, 76 μmol) was dissolved in dichloromethane / water (7.6 mL, 40:1, v / v). DDQ (dichlorodicyanobenzoquinone, 34 mg, 150 μmol) was added at 0 °C. The reaction system was slowly heated to room temperature at 0 °C for a total of 3 hours. The reaction was complete as monitored by TLC. The reaction system was diluted with dichloromethane at 0 °C. The reaction was quenched by slowly adding an appropriate amount of saturated sodium bicarbonate solution. The mixture was extracted with saturated sodium bicarbonate solution and saturated sodium chloride solution, respectively. The organic phases were combined, dried with anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (n-hexane / EtOAc, 3:1) to obtain colorless syrupy tetrasaccharide receptor 10, i.e., compound 10 (105 mg, 53 μmol, 70%).

[0055] R f = 0.43 (DCM / CH3OH = 20:1). = -67.9 (c 0.53, CHCl3); 1H NMR (400MHz, CDCl3) δ 8.06 (d, J = 7.3 Hz, 2H), 7.91 (d, J = 7.0 Hz, 2H), 7.78 (d, J= 7.1 Hz, 2H), 7.60 – 7.52 (m, 2H), 7.49 – 7.41 (m, 8H), 7.39 – 7.34 (m, 5H),7.34 – 7.31 (m, 6H), 7.30 – 7.26 (m, 21H), 7.25 – 7.23 (m, 3H), 7.22 – 7.15(m, 4H), 7.13 – 7.09 (m, 3H), 7.02 – 6.98 (m, 2H), 5.99 (d, J = 7.0 Hz, 1H),5.61 (t, J = 2.5 Hz, 1H), 5.54 (dd, J = 8.6, 3.3 Hz, 1H), 5.51 (s, 1H), 5.44(d, J = 3.3 Hz, 1H), 5.32 (d, J = 1.9 Hz, 1H), 5.22 – 5.18 (m, 1H), 5.14 (d,J = 3.5 Hz, 1H), 5.07 (d, J = 3.3 Hz, 2H), 4.98 – 4.92 (m, 2H), 4.90 – 4.87(m, 1H), 4.86 – 4.81 (m, 2H), 4.72 (d, J = 11.2 Hz, 1H), 4.65 (d, J = 6.5 Hz,1H), 4.64 – 4.57 (m, 4H), 4.57 – 4.52 (m, 2H), 4.51 (s, 1H), 4.50 (s, 1H),4.47 – 4.43 (m, 1H), 4.39 – 4.30 (m, 5H), 4.28 – 4.23 (m, 1H), 4.14 – 4.10(m, 1H), 4.03 – 3.98 (m, 2H), 3.94 – 3.88 (m, 1H), 3.84 – 3.78 (m, 3H), 3.76– 3.69 (m, 4H), 3.68 – 3.64 (m, 2H), 3.61 (d, J = 5.5 Hz, 1H), 3.59 – 3.52(m, 1H), 3.52 – 3.43 (m, 2H), 3.34 – 3.27 (m, 1H), 3.23 – 3.16 (m, 1H), 1.80– 1.74 (m, 2H), 1.65 (s, 3H), 0.69 (d, J = 6.4 Hz, 3H). 13 C NMR (150 MHz,CDCl3) δ 171.5, 166.3, 165.2, 165.1, 156.5, 139.1, 138.6, 138.3, 138.1,138.0, 137.9, 137.8, 137.1, 136.5, 133.3, 133.1, 132.9, 130.0, 129.9, 129.7,129.7, 129.5, 129.5, 129.2, 128.7, 128.5, 128.5, 128.5, 128.5, 128.4, 128.4,128.3, 128.3, 128.3, 128.3, 128.2, 128.2, 128.1, 128.1, 128.1, 128.0, 127.9,127.8, 127.8, 127.7, 127.6, 127.6, 127.5, 127.5, 127.4, 127.3, 127.3, 126.3,101.7, 100.3, 99.4, 98.1, 97.7, 80.6, 79.4, 78.8, 76.7, 76.3, 75.6, 75.2,74.8, 74.7, 74.5, 73.9, 73.8, 73.6, 73.3, 73.2, 73.0, 72.9, 72.8, 72.3, 71.6,71.6, 71.3, 70.7, 68.6, 66.6, 66.4, 65.9, 65.1, 60.7, 57.8, 38.3, 29.4, 23.2,15.7. HRMS (ESI): m / z calcd for C 116 H 121 N2O 27 [M+H] + 1973.8157, found:1973.8160.

[0056] S4. Construction of the fully protected hexasaccharide backbone: Tetrasaccharide acceptor 10 (50 mg, 25 μmol) and disaccharothioglycoside donor 11 (78 mg, 75 μmol) were dissolved in dry toluene (3.8 mL), and activated 4 Å molecular sieve (380 mg) was added at room temperature. The reaction system was stirred at room temperature for 15 minutes under nitrogen atmosphere. Subsequently, the reaction system was placed in a low temperature bath at -78 °C and stirred for 15 minutes. NIS (25 mg, 110 μmol) and TfOH (1.3 μL, 15 μmol) were added to the reaction system in sequence, and the reaction temperature was slowly raised to -10 °C and reacted at -10 °C for 1 hour. The receptor reaction was complete as monitored by TLC. Triethylamine was slowly added to adjust the pH of the reaction system to neutral. The mixture was filtered, and the filtrate was diluted with ethyl acetate. It was then extracted successively with saturated sodium thiosulfate solution and saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (petroleum ether / EtOAc, 1:1) to obtain a colorless syrupy fully protected hexasaccharide backbone 12, namely compound 12 (62 mg, 21 μmol, 82%).

[0057] R f =0.57 (DCM / CH3OH = 30:1). = -9.3 (c 0.43, CHCl3); 1H NMR (400MHz, CDCl3) δ 8.02 – 7.93 (m, 8H), 7.79 (d, J = 7.0 Hz, 2H), 7.58 – 7.52 (m,2H), 7.52 – 7.38 (m, 11H), 7.37 – 7.29 (m, 23H), 7.28 – 7.25 (m, 14H), 7.24 –7.21 (m, 9H), 7.21 – 7.15 (m, 13H), 7.14 – 7.06 (m, 9H), 7.03 – 6.99 (m, 2H),6.97 – 6.93 (m, 2H), 5.81 – 5.72 (m, 1H), 5.65 – 5.62 (m, 1H), 5.58 (dd, J =10.3, 7.9 Hz, 1H), 5.53 (dd, J = 9.0, 3.2 Hz, 1H), 5.47 (s, 1H), 5.41 (d, J =3.2 Hz, 1H), 5.36 (s, 1H), 5.32 – 5.26 (m, 1H), 5.18 – 5.12 (m, 1H), 5.09 –5.06 (m, 2H), 5.03 (d, J = 3.4 Hz, 1H), 4.99 (d, J = 12.1 Hz, 1H), 4.92 –4.87 (m, 3H), 4.87 – 4.82 (m, 2H), 4.81 – 4.78 (m, 1H), 4.76 – 4.66 (m, 4H),4.65 – 4.61 (m, 3H), 4.60 – 4.58 (m, 2H), 4.57 – 4.53 (m, 2H), 4.52 – 4.49(m, 3H), 4.48 – 4.43 (m, 4H), 4.42 – 4.36 (m, 2H), 4.36 – 4.22 (m, 8H), 4.22– 4.17 (m, 2H), 4.16 – 4.12 (m, 1H), 4.10 – 4.03 (m, 2H), 3.99 – 3.92 (m,2H), 3.92 – 3.80 (m, 3H), 3.77 – 3.70 (m, 4H), 3.70 – 3.61 (m, 4H), 3.60 –3.46 (m, 6H), 3.41 – 3.33 (m, 1H), 3.27 – 3.05 (m, 3H), 1.73 – 1.64 (m, 2H),1.56 (s, 3H), 0.57 (d, J = 6.4 Hz, 3H). 13 C NMR (100 MHz, CDCl3) δ 171.3,166.5, 166.1, 165.3, 165.1, 165.0, 156.5, 139.2 – 136.7 (C-Ar), 133.3 – 132.9(C-Ar), 130.2 – 126.5 (C-Ar), 102.1, 101.9, 99.9, 99.4, 98.7, 98.0, 97.9,81.8, 80.8, 80.7, 79.8, 79.5, 78.6, 77.9, 77.8, 75.7, 75.3, 75.2, 74.8, 74.7,74.5, 74.5, 74.5, 74.1, 74.1, 74.0, 73.6, 73.4, 73.3, 73.2, 73.1, 73.0, 73.0,72.9, 72.8, 72.4, 71.9, 71.8, 71.6, 71.5, 71.2, 70.8, 69.5, 68.8, 68.8, 67.4,66.6, 66.4, 65.5, 65.1, 63.1, 59.2, 38.4, 29.5, 23.4, 15.6. HRMS (ESI): m / zcalcd for C 177 H 186 N4O 39 [M+2NH4] + 1495.6322, found: 1495.6384.

[0058] S5. Global Deprotection: The fully protected hexasaccharide backbone 12 (30 mg, 10 μmol) was dissolved in tetrahydrofuran / methanol (2.0 mL, 3:1, v / v), and 1 M NaOH (0.2 mL) was added at 0 °C. The reaction system was stirred at room temperature for 12 hours. TLC monitoring showed that the reaction was complete. The reaction solution was diluted with methanol and then analyzed using Amberlite IR 120 H. +The cation exchange resin was neutralized to pH neutral, and the filtrate was concentrated under reduced pressure after filtration to obtain the crude product for subsequent reactions. The crude product was dissolved in methanol / tetrahydrofuran / water (2 mL, 2:1:1, v / v / v), and 20% Pd(OH)₂ / C (20 mg) was added. The reaction was carried out under hydrogen atmosphere for 24 hours. After the reaction, the catalyst was removed by filtration, and the filtrate was freeze-dried to obtain the crude product. The crude product was purified by size exclusion chromatography (BioGel P-2, eluent: 0.05 M NH₄HCO₃ solution). The target fraction was collected and freeze-dried to obtain a white solid, namely compound 1 (7.6 mg, 6.7 μmol, 66%). The proton and carbon spectra of compound 1 are shown below. Figure 1 and Figure 2 As shown, the specific data is as follows:

[0059] = +5.4 (c 0.13, H2O); 1H NMR (400 MHz, D2O) δ 5.07 (d, J = 1.7Hz, 1H), 5.01 (d, J = 4.1 Hz, 1H), 4.94 (d, J = 3.9 Hz, 1H), 4.82 (s, 1H),4.57 (d, J = 8.5 Hz, 1H), 4.53 (d, J = 7.7 Hz, 1H), 4.38 – 4.32 (m, 1H), 4.22(d, J = 8.6 Hz, 1H), 4.19 – 4.14 (m, 1H), 4.12 (d, J = 10.8 Hz, 1H), 4.06 (d,J = 3.8 Hz, 1H), 4.05 – 4.02 (m, 3H), 3.99 (d, J = 3.2 Hz, 1H), 3.96 – 3.93(m, 1H), 3.93 – 3.90 (m, 2H), 3.87 (d, J = 3.3 Hz, 1H), 3.86 – 3.82 (m, 5H),3.82 – 3.80 (m, 3H), 3.79 – 3.77 (m, 3H), 3.77 – 3.74 (m, 3H), 3.73 – 3.72(m, 1H), 3.72 – 3.69 (m, 1H), 3.67 – 3.64 (m, 2H), 3.63 – 3.62 (m, 1H), 3.61– 3.59 (m, 1H), 3.57 (d, J = 5.3 Hz, 1H), 3.56 – 3.51 (m, 2H), 3.48 (d, J =10.0 Hz, 1H), 3.45 – 3.42 (m, 1H), 3.10 – 3.00 (m, 2H), 2.05 (s, 3H), 1.99 –1.90 (m, 2H), 1.15 (d, J = 6.5 Hz, 3H). 13C NMR (150 MHz, D2O) δ 174.1, 103.5,101.9, 99.9, 99.8, 99.3, 97.1, 79.8, 76.9, 76.6, 76.3, 75.8, 75.1, 73.5,73.4, 72.6, 71.9, 71.7, 71.7, 71.4, 71.3, 70.8, 70.5, 70.1, 69.7, 69.7, 69.6,69.1, 68.3, 67.3, 67.3, 67.2, 66.8, 65.1, 61.4, 60.6, 60.0, 59.9, 55.0, 37.4,27.6, 22.4, 15.0. HRMS (ESI): m / z calcd for C 43 H 77 N2O 32 [M+H] + 1133.4460, found: 1133.4467.

[0060] Example 2:

[0061] A Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen, the structural formula of which is as follows:

[0062] .

[0063] Its preparation method includes the following steps:

[0064] Steps S1-S3 are the same as in Example 1. In step S4, tetrasaccharide receptor 10 (30 mg, 13 μmol) was dissolved in tetrahydrofuran / methanol (2.6 mL, 3:1, v / v), and 1 M NaOH (0.26 mL) was added at 0 °C. The reaction system was stirred at room temperature for 12 hours, and TLC monitoring showed that the reaction was complete. After diluting the reaction solution with methanol, it was analyzed using Amberlite IR120 H. + The cation exchange resin was neutralized to pH neutral, and the filtrate was concentrated under reduced pressure after filtration to obtain the crude product for subsequent reactions. The crude product was dissolved in methanol / tetrahydrofuran / water (2.6 mL, 2:1:1, v / v / v), and 20% Pd(OH)₂ / C (20 mg) was added. The reaction was carried out under hydrogen atmosphere for 24 hours. After the reaction, the catalyst was removed by filtration, and the filtrate was freeze-dried to obtain the crude product. The crude product was purified by size exclusion chromatography (BioGel P-2, eluent: 0.05 M NH₄HCO₃ solution). The target fraction was collected and freeze-dried to obtain a white solid, compound 2 (7.4 mg, 9.2 μmol, 69%). The proton and carbon spectra of compound 2 are shown below. Figure 3 and Figure 4 As shown, the specific data is as follows:

[0065] = -19.0 (c 0.50, H2O); 1 H NMR (400 MHz, D2O) δ 5.07 (d, J = 1.8Hz, 1H), 5.01 (d, J = 4.0 Hz, 1H), 4.83 (d, J = 1.6 Hz, 1H), 4.56 (d, J = 8.5Hz, 1H), 4.37 – 4.32 (m, 1H), 4.07 (dd, J = 3.5, 1.6 Hz, 1H), 4.05 – 4.00 (m,3H), 4.00 – 3.98 (m, 1H), 3.96 – 3.90 (m, 2H), 3.88 – 3.85 (m, 1H), 3.85 –3.83 (m, 2H), 3.83 – 3.81 (m, 1H), 3.81 – 3.80 (m, 1H), 3.80 – 3.79 (m, 1H), 3.79 – 3.77 (m, 2H), 3.76 – 3.69 (m, 3H), 3.67 – 3.60 (m, 4H), 3.59 – 3.56(m, 1H), 3.55 – 3.52 (m, 1H), 3.47 – 3.41 (m, 1H), 3.07 – 2.98 (m, 2H), 2.04(s, 3H), 1.97 – 1.89 (m, 2H), 1.15 (d, J = 6.6 Hz, 3H). 13 C NMR (100 MHz, D2O)δ 174.3, 102.0, 99.9, 99.1, 97.0, 79.8, 76.6, 76.0, 75.8, 73.6, 73.4, 71.5,71.3, 71.0, 70.5, 69.8, 69.7, 68.4, 67.4, 67.3, 67.3, 66.8, 65.0, 61.4, 61.2,60.6, 55.1, 37.4, 26.7, 22.2, 15.0. HRMS (ESI): m / z calcd for C 31 H 57 N2O 22 [M+H] + 809.3403, found: 809.3405.

[0066] Example 3:

[0067] A Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen, the structural formula of which is as follows:

[0068] .

[0069] Its preparation method includes the following steps:

[0070] S1. Construction of the disaccharide backbone: Monosaccharide acceptor 6 (60 mg, 74 μmol) and monosaccharide glucosinolate donor 13 (89 mg, 140 μmol) were dissolved in dry dichloromethane (4.7 mL). Activated 4 Å molecular sieve (0.94 g) was added at room temperature. The reaction system was stirred at room temperature for 15 minutes under nitrogen atmosphere. Subsequently, the reaction system was placed in a low-temperature bath at -78 °C and stirred for 15 minutes. NIS (47 mg, 210 μmol) and TfOH (2.5 μL, 28 μmol) were added to the reaction system in sequence. The reaction temperature was slowly raised to -30 °C and reacted at -30 °C for 30 minutes. The receptor reaction was complete as monitored by TLC. Triethylamine was slowly added to adjust the pH of the reaction system to neutral. The mixture was filtered, and the filtrate was diluted with ethyl acetate. It was then extracted successively with saturated sodium thiosulfate solution and saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (petroleum ether / EtOAc, 3:1) to obtain colorless syrupy disaccharide 14, i.e., compound 14 (62 mg, 21 μmol, 81%).

[0071] R f = 0.21 (petroleum ether / EtOAc = 2:1). = -4.8 (c 0.27, CHCl3). 1H NMR (400 MHz, CDCl3) δ 7.84 – 7.73 (m, 4H), 7.49 – 7.41 (m, 5H), 7.40 –7.33 (m, 10H), 7.33 – 7.27 (m, 8H), 7.26 – 7.23 (m, 3H), 7.17 – 7.12 (m, 2H),6.16 (s, 1H), 5.53 – 5.46 (m, 2H), 5.18 (d, J = 12.3 Hz, 1H), 5.07 (d, J =12.2 Hz, 1H), 5.05 – 4.99 (m, 2H), 4.88 (d, J = 2.8 Hz, 1H), 4.82 (d, J =12.0 Hz, 1H), 4.79 – 4.72 (m, 3H), 4.69 (d, J = 12.1 Hz, 1H), 4.66 – 4.63 (m,2H), 4.60 – 4.54 (m, 2H), 4.50 (d, J = 10.9 Hz, 1H), 4.32 (dd, J = 10.5, 4.9Hz, 1H), 4.09 – 4.05 (m, 1H), 4.00 – 3.91 (m, 2H), 3.90 – 3.80 (m, 3H), 3.78(d, J = 4.1 Hz, 1H), 3.74 – 3.69 (m, 2H), 3.68 – 3.62 (m, 2H), 3.59 – 3.51(m, 1H), 3.49 – 3.40 (m, 2H), 3.12 – 3.02 (m, 1H), 2.72 – 2.64 (m, 2H), 2.60– 2.54 (m, 2H), 2.05 (s, 3H), 1.71 – 1.65 (m, 2H). 13C NMR (100 MHz, CDCl3) δ206.3, 172.2, 157.14, 154.4, 139.1, 138.4, 138.4, 137.1, 136.6, 136.1, 133.4,133.0, 129.2, 128.6, 128.4, 128.4, 128.4, 128.4, 128.4, 128.3, 128.2, 128.2,128.2, 128.0, 128.0, 127.8, 127.8, 127.7, 127.6, 127.4, 126.4, 126.3, 126.1,125.9, 101.5, 101.2, 98.1, 95.8, 78.8, 78.7, 78.5, 76.2, 75.1, 74.6, 74.1,73.4, 72.6, 72.4, 72.3, 71.4, 70.9, 68.7, 67.2, 66.5, 64.2, 57.0, 38.1, 37.9,29.8, 29.8, 28.1. HRMS (ESI): m / z calcd for C 71 H 79 NCl3N2O 17 [M+NH4] + 1350.4475, found: 1350.4480.

[0072] One-pot conversion of S2, N-Troc to N-Ac: Disaccharide 14 (50 mg, 37 μmol) was dissolved in tetrahydrofuran (1.0 mL). Activated zinc powder (100 mg), acetic anhydride (1.0 mL), acetic acid (0.5 mL), and saturated copper sulfate solution (0.5 mL) were added sequentially at 0 °C. The reaction system was incubated at room temperature for 2 hours. TLC monitoring showed complete substrate reaction. The mixture was filtered, and the filtrate was diluted with an appropriate amount of ethyl acetate and placed at 0 °C. The reaction was quenched by slow addition of saturated sodium bicarbonate solution. The mixture was extracted sequentially with saturated sodium bicarbonate solution and saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (DCM / CH3OH, 30:1) to obtain a colorless syrupy product, compound 15 (37 mg, 31 μmol, 84%).

[0073] R f = 0.26 (DCM / CH3OH = 30:1). = -7.0 (c 0.17, CHCl3); 1H NMR (400MHz, CDCl3) δ 7.83 – 7.72 (m, 4H), 7.47 – 7.41 (m, 5H), 7.38 – 7.33 (m, 7H),7.33 – 7.29 (m, 6H), 7.29 – 7.26 (m, 4H), 7.26 – 7.22 (m, 4H), 7.16 – 7.10(m, 2H), 6.16 (d, J = 8.4 Hz, 1H), 5.54 – 5.47 (m, 2H), 5.19 – 5.14 (m, 1H),5.14 – 5.04 (m, 3H), 4.84 – 4.76 (m, 2H), 4.74 – 4.70 (m, 2H), 4.69 – 4.65(m, 2H), 4.63 (d, J = 12.3 Hz, 1H), 4.53 (d, J = 11.4 Hz, 1H), 4.49 (d, J =11.1 Hz, 1H), 4.30 (dd, J = 10.3, 4.8 Hz, 1H), 4.06 – 3.96 (m, 2H), 3.91 –3.84 (m, 3H), 3.83 – 3.77 (m, 2H), 3.76 – 3.65 (m, 4H), 3.60 – 3.53 (m, 1H),3.51 – 3.44 (m, 1H), 3.40 – 3.29 (m, 1H), 3.17 – 3.08 (m, 1H), 2.81 – 2.73(m, 1H), 2.70 – 2.57 (m, 2H), 2.54 – 2.47 (m, 1H), 2.08 (s, 3H), 1.83 (s,3H), 1.76 – 1.67 (m, 2H). 13C NMR (100 MHz, CDCl3) δ 206.8, 172.3, 170.8,156.8, 138.8, 138.5, 138.4, 137.2, 136.7, 136.2, 133.4, 133.0, 129.2, 128.6,128.4, 128.4, 128.4, 128.3, 128.3, 128.2, 128.1, 128.1, 128.0, 128.0, 127.8,127.8, 127.7, 127.5, 126.4, 126.3, 126.3, 126.1, 125.9, 125.8, 101.5, 100.7,97.7, 78.9, 78.8, 78.1, 75.5, 74.9, 74.5, 73.3, 72.8, 72.3, 72.0, 71.5, 70.8,68.7, 66.9, 66.4, 64.5, 55.8, 38.2, 38.1, 29.8, 29.5, 28.2, 23.4. HRMS (ESI):m / z calcd for C 70 H 77 N2O 16 [M+H] + 1201.5273, found: 1201.5280.

[0074] Selective removal of S3 and Nap protecting groups: Compound 15 (35 mg, 29 μmol) was dissolved in dichloromethane / deionized water (2.0 mL, 40:1, v / v), and DDQ (10 mg, 44 μmol) was added at 0 °C. The reaction system was slowly heated to room temperature for a total of 3 hours. TLC monitoring showed that the substrate reaction was complete. The reaction system was diluted with dichloromethane at 0 °C, and the reaction was quenched by slowly adding an appropriate amount of saturated sodium bicarbonate solution. The mixture was extracted with saturated sodium bicarbonate solution and saturated sodium chloride solution, and the organic phases were combined. After drying with anhydrous sodium sulfate, the mixture was filtered and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (DCM / CH3OH, 25:1) to obtain colorless syrupy disaccharide receptor 16, i.e., compound 16 (23 mg, 22 μmol, 77%).

[0075] R f = 0.24 (DCM / CH3OH = 30:1). = -6.8 (c 0.73, CHCl3); 1H NMR (400MHz, CDCl3) δ 7.48 – 7.44 (m, 2H), 7.38 – 7.34 (m, 6H), 7.33 – 7.31 (m, 5H),7.30 – 7.27 (m, 10H), 7.22 – 7.18 (m, 2H), 6.40 (d, J = 8.7 Hz, 1H), 5.49 (s,1H), 5.42 (t, J = 10.0 Hz, 1H), 5.21 – 5.16 (m, 1H), 5.13 (d, J = 12.2 Hz,1H), 5.08 (d, J = 12.4 Hz, 1H), 4.90 – 4.81 (m, 3H), 4.70 (d, J = 11.2 Hz,1H), 4.63 (d, J = 12.3 Hz, 1H), 4.59 – 4.50 (m, 3H), 4.31 (dd, J = 10.4, 4.8Hz, 1H), 4.07 – 3.98 (m, 3H), 3.88 – 3.84 (m, 2H), 3.84 – 3.80 (m, 3H), 3.76– 3.67 (m, 3H), 3.60 – 3.52 (m, 2H), 3.43 – 3.33 (m, 1H), 3.20 – 3.09 (m,1H), 2.79 – 2.65 (m, 2H), 2.61 – 2.49 (m, 2H), 2.08 (s, 3H), 1.96 (s, 3H),1.83 – 1.72 (m, 2H). 13C NMR (100 MHz, CDCl3) δ 206.5, 172.7, 171.7, 156.8,138.6, 138.4, 138.3, 137.1, 136.6, 129.2, 128.6, 128.5, 128.5, 128.4, 128.4,128.4, 128.2, 128.2, 128.2, 128.1, 128.0, 127.8, 127.7, 126.2, 101.7, 101.4,97.4, 79.0, 78.6, 76.4, 75.6, 74.9, 74.8, 73.0, 71.8, 71.6, 71.5, 68.6, 66.9,66.4, 64.4, 60.7, 55.2, 38.1, 38.1, 29.7, 29.4, 28.3, 23.5. HRMS (ESI): m / zcalcd for C 59 H 69 N2O 16 [M+H] + 1061.4647, found: 1061.4651.

[0076] S4. Construction of the tetrasaccharide backbone: Disaccharide acceptor 16 (20 mg, 19 μmol) and disaccharoside donor 11 (40 mg, 38 μmol) were dissolved in dry toluene (1.9 mL). Activated 4 Å molecular sieve (190 mg) was added at room temperature, and the reaction system was stirred at room temperature for 15 minutes under nitrogen atmosphere. Subsequently, the reaction system was placed in a low-temperature bath at -78 °C and stirred for 15 minutes. NIS (13 mg, 57 μmol) and TfOH (0.7 μL, 8 μmol) were added to the reaction system sequentially, and the reaction temperature was slowly raised to -10 °C. The reaction was carried out at -10 °C for 1 hour. TLC monitoring showed that the acceptor reaction was complete. Triethylamine was added to adjust the pH of the reaction system to neutral, and the mixture was filtered. The filtrate was diluted with ethyl acetate and extracted sequentially with saturated sodium thiosulfate solution and saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was subjected to silica gel column chromatography (petroleum chromatography). The tetrasaccharide 17 (33 mg, 15 μmol, 80%) was isolated and purified by ether / EtOAc (1:1) to obtain a colorless syrupy tetrasaccharide 17.

[0077] R f = 0.43 (DCM / CH3OH = 30:1). = +34.3 (c 0.23, CHCl3);1H NMR (400MHz, CDCl3) δ 7.99 – 7.94 (m, 4H), 7.55 – 7.49 (m, 2H), 7.47 – 7.43 (m, 2H),7.41 – 7.37 (m, 2H), 7.36 – 7.31 (m, 13H), 7.31 – 7.27 (m, 14H), 7.25 – 7.20(m, 8H), 7.19 – 7.11 (m, 13H), 7.02 – 6.98 (m, 2H), 6.03 (s, 1H), 5.64 (t, J= 9.9 Hz, 1H), 5.58 (dd, J = 10.3, 7.9 Hz, 1H), 5.46 (s, 1H), 5.23 (d, J =8.2 Hz, 1H), 5.17 – 5.06 (m, 3H), 5.05 (d, J = 3.6 Hz, 1H), 4.94 (d, J = 10.5Hz, 1H), 4.91 – 4.86 (m, 2H), 4.84 (d, J = 11.9 Hz, 1H), 4.79 – 4.67 (m, 5H),4.63 (d, J = 11.2 Hz, 1H), 4.57 – 4.54 (m, 1H), 4.53 – 4.46 (m, 4H), 4.46 –4.41 (m, 2H), 4.36 – 4.31 (m, 1H), 4.30 – 4.26 (m, 3H), 4.26 – 4.24 (m, 1H),4.24 – 4.20 (m, 1H), 4.19 – 4.16 (m, 1H), 4.16 – 4.11 (m, 1H), 4.07 – 4.03(m, 1H), 4.02 – 3.99 (m, 1H), 3.90 – 3.81 (m, 3H), 3.77 (d, J = 10.4 Hz, 1H),3.72 (d, J = 9.5 Hz, 1H), 3.69 – 3.66 (m, 2H), 3.65 – 3.61 (m, 2H), 3.60 –3.54 (m, 5H), 3.46 – 3.37 (m, 2H), 3.34 – 3.26 (m, 1H), 3.18 – 3.09 (m, 1H),2.84 – 2.57 (m, 2H), 2.57 – 2.39 (m, 2H), 2.06 (s, 3H), 1.76 (s, 3H), 1.73 –1.64 (m, 2H). 13 C NMR (100 MHz, CDCl3) δ 206.5, 172.2, 172.0, 166.2, 165.3,156.7, 139.0, 138.7, 138.6, 138.3, 138.3, 138.2, 138.2, 137.5, 137.2, 136.7,133.0, 132.9, 130.3, 130.2, 130.0, 129.9, 129.9, 129.8, 129.8, 129.2, 129.1,128.6, 128.6, 128.6, 128.5, 128.5, 128.4, 128.4, 128.4, 128.3, 128.3, 128.2, 128.1, 128.1, 128.1, 127.9, 127.8, 127.8, 127.8, 127.8, 127.8, 127.7, 127.7, 127.6, 127.6, 127.6, 127.2, 127.1, 126.4, 102.2, 101.6, 100.0, 99.8, 97.7, 81.9, 80.8, 79.5, 79.2, 79.1, 78.6, 78.1, 77.9, 75.9, 75.2, 74.9, 74.8, 74.6, 73.9,73.6, 73.1, 73.1, 72.9, 72.8, 72.1, 71.7, 71.7, 70.9, 69.6, 68.8, 67.6, 66.8,66.3, 64.8, 63.2, 56.5, 38.3, 38.1, 29.8, 29.6, 28.0, 23.2. HRMS (ESI): m / zcalcd for C 121 H 133 N2Cl3N2O 29 [M+2NH4] + 1105.4043, found: 1105.4048.

[0078] S5. Global Deprotection: Tetrasaccharide 17 (30 mg, 13.8 μmol) was dissolved in tetrahydrofuran / methanol (2.8 mL, 3:1, v / v), and 1 M NaOH (0.28 mL) was added at 0 °C. The reaction system was stirred at room temperature for 12 hours. TLC monitoring showed that the reaction was complete. The reaction solution was diluted with methanol and then analyzed using Amberlite IR 120 H. +The cation exchange resin was neutralized to pH neutral, and the filtrate was concentrated under reduced pressure after filtration to obtain the crude product for subsequent reactions. The crude product was dissolved in methanol / tetrahydrofuran / water (2.8 mL, 2:1:1, v / v / v), and 20% Pd(OH)₂ / C (20 mg) was added. The reaction was carried out under hydrogen atmosphere for 24 hours. After the reaction, the catalyst was removed by filtration, and the filtrate was freeze-dried to obtain the crude product. The crude product was purified by size exclusion chromatography (BioGel P-2, eluent: 0.05 M NH₄HCO₃ solution). The target fraction was collected and freeze-dried to obtain a white solid, compound 3 (7.3 mg, 9.2 μmol, 67%). The proton and carbon spectra of compound 3 are shown below. Figure 5 and Figure 6 As shown, the specific data is as follows:

[0079] = +16.5 (c 0.17, H2O); 1 H NMR (400 MHz, D2O) δ 4.94 (d, J = 3.9Hz, 1H), 4.84 (s, 1H), 4.56 (d, J = 8.2 Hz, 1H), 4.53 (d, J = 8.0 Hz, 1H), 4.24 – 4.20 (m, 1H), 4.18 – 4.14 (m, 1H), 4.14 – 4.09 (m, 1H), 4.08 – 4.06(m, 1H), 4.04 (d, J = 3.1 Hz, 1H), 3.96 – 3.92 (m, 1H), 3.90 (s, 1H), 3.88 –3.86 (m, 1H), 3.86 – 3.84 (m, 1H), 3.83 – 3.80 (m, 2H), 3.79 – 3.77 (m, 2H), 3.76 – 3.74 (m, 2H), 3.73 – 3.72 (m, 1H), 3.71 – 3.64 (m, 3H), 3.63 – 3.62(m, 1H), 3.61 – 3.59 (m, 1H), 3.58 – 3.52 (m, 3H), 3.49 – 3.46 (m, 1H), 3.46– 3.41 (m, 2H), 3.16 – 3.10 (m, 2H), 2.07 (s, 3H), 2.05 – 1.94 (m, 2H). 13CNMR (150 MHz, D2O) δ 174.2, 103.5, 99.9, 99.6, 97.2, 76.9, 76.3, 75.7, 75.1,73.4, 73.4, 72.6, 71.9, 71.8, 71.7, 70.8, 70.2, 69.8, 69.8, 69.7, 69.1, 67.2,65.0, 60.6, 60.0, 59.9, 55.2, 37.4, 26.6, 22.3. HRMS (ESI): m / z calcd forC 30 H 55 N2O 22 [M+H] + 795.3247, found: 795.3250.

[0080] Example 4:

[0081] A Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen, the structural formula of which is as follows:

[0082] .

[0083] Its preparation method includes the following steps:

[0084] S1. Construction of the trisaccharide backbone: Monosaccharide acceptor 18 (50 mg, 64 μmol) and disaccharide ethioglycoside donor 11 (134 mg, 128 μmol) were dissolved in dry toluene (4.3 mL). Activated 4 Å molecular sieve (430 mg) was added at room temperature. The reaction system was stirred at room temperature for 15 minutes under nitrogen atmosphere. Subsequently, the reaction system was placed in a -78 °C cryogenic bath and stirred for 15 minutes. NIS (43 mg, 192 μmol) and TfOH (2.3 μL, 26 μmol) were added sequentially to the reaction system. The reaction temperature was slowly raised to -20 °C. The reaction was carried out at ℃ for 30 minutes. The acceptor reaction was complete as monitored by TLC. Triethylamine was slowly added to adjust the pH of the reaction system to neutral. The mixture was filtered, and the filtrate was diluted with ethyl acetate. It was then extracted successively with saturated sodium thiosulfate solution and saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography (petroleum ether / EtOAc, 4:1) to obtain colorless syrupy trisaccharide 19, i.e., compound 19 (93 mg, 53 μmol, 83%).

[0085] R f = 0.22 (petroleum ether / EtOAc = 3:1). = +47.2 (c 0.47,CHCl3); 1 H NMR (400 MHz, CDCl3) δ 7.99 – 7.92 (m, 6H), 7.54 – 7.44 (m, 3H),7.41 – 7.35 (m, 4H), 7.34 – 7.26 (m, 18H), 7.25 – 7.22 (m, 6H), 7.22 – 7.19(m, 9H), 7.19 – 7.12 (m, 10H), 7.11 – 7.06 (m, 2H), 7.00 – 6.96 (m, 2H), 5.60(dd, J = 10.3, 7.9 Hz, 1H), 5.50 (t, J = 2.3 Hz, 1H), 5.10 (d, J = 3.5 Hz,1H), 5.09 – 5.04 (m, 2H), 5.01 – 4.96 (m, 1H), 4.94 – 4.85 (m, 4H), 4.83 (d,J = 6.0 Hz, 1H), 4.79 (s, 1H, H-1), 4.76 (d, J = 4.4 Hz, 1H), 4.73 (d, J =3.7 Hz, 1H), 4.70 (d, J = 11.2 Hz, 1H), 4.63 (d, J = 11.2 Hz, 1H), 4.59 (d, J= 10.8 Hz, 1H), 4.56 – 4.50 (m, 4H), 4.49 – 4.42 (m, 2H), 4.32 – 4.17 (m,6H), 4.15 – 4.09 (m, 2H), 4.02 – 3.92 (m, 3H), 3.81 – 3.77 (m, 1H), 3.76 –3.68 (m, 3H), 3.60 (dd, J = 10.1, 3.5 Hz, 1H), 3.57 – 3.53 (m, 1H), 3.51 (dd,J = 8.5, 5.3 Hz, 1H), 3.46 – 3.37 (m, 2H), 3.29 – 3.16 (m, 2H), 1.78 – 1.72(m, 2H). 13C NMR (100 MHz, CDCl3) δ 166.1, 165.8, 165.3, 156.4, 138.9, 138.7,138.6, 138.3, 138.1, 138.1, 138.0, 137.5, 136.8, 133.2, 133.0, 132.9, 130.3,130.1, 129.9, 129.8, 129.8, 128.6, 128.6, 128.6, 128.5, 128.5, 128.5, 128.5,128.5, 128.4, 128.4, 128.3, 128.3, 128.2, 128.2, 128.2, 128.2, 128.1, 128.1, 128.1, 128.1, 127.9, 127.9, 127.8, 127.7, 127.7, 127.7, 127.7, 127.7, 127.7, 127.6, 127.1, 102.2, 100.0, 97.7, 81.9, 80.9, 79.7, 78.8, 78.1, 77.9, 75.8, 75.2, 74.7, 74.5, 74.1, 74.0, 73.5, 73.3, 73.2, 73.1, 71.8, 71.7, 71.6, 71.6,69.5, 69.0, 67.3, 66.7, 65.9, 63.2, 38.7, 29.5. HRMS (ESI): m / z calcd forC 107 H 108 NO 22 [M+H] + 1758.7363, found: 1758.7366.

[0086] S2, Global Deprotection: Trisaccharide 19 (30 mg, 17 μmol) was dissolved in tetrahydrofuran / methanol (3.4 mL, 3:1, v / v), and 1 M NaOH (0.34 mL) was added at 0 °C. The reaction system was stirred at room temperature for 12 hours. TLC monitoring showed that the reaction was complete. The reaction solution was diluted with methanol and then analyzed using Amberlite IR 120 H. +The cation exchange resin was neutralized to pH neutral, and the filtrate was concentrated under reduced pressure after filtration to obtain the crude product for subsequent reactions. The crude product was dissolved in methanol / tetrahydrofuran / water (3.4 mL, 2:1:1, v / v / v), and 20% Pd(OH)₂ / C (20 mg) was added. The reaction was carried out under hydrogen atmosphere for 24 hours. After the reaction, the catalyst was removed by filtration, and the filtrate was freeze-dried to obtain the crude product. Purification was performed by size exclusion chromatography (BioGel P-2, eluent: 0.05 M NH₄HCO₃ solution). The target fraction was collected and freeze-dried to obtain a white solid, compound 4 (7.4 mg, 12.6 mol, 74%). The proton and carbon spectra of compound 4 are shown below. Figure 7 and Figure 8 As shown, the specific data is as follows:

[0087] = +52.8 (c 0.83, H2O); 1 H NMR (600 MHz, D2O) δ 4.95 (d, J = 3.8Hz, 1H), 4.88 (d, J = 1.8 Hz, 1H), 4.55 (d, J = 7.7 Hz, 1H), 4.27 – 4.24 (m,1H), 4.22 (dd, J = 10.9, 3.0 Hz, 1H), 4.19 – 4.15 (m, 1H), 4.05 (d, J = 3.2Hz, 1H), 3.98 – 3.95 (m, 1H), 3.95 – 3.88 (m, 2H), 3.88 – 3.84 (m, 2H), 3.84– 3.80 (m, 3H), 3.80 – 3.78 (m, 3H), 3.77 – 3.75 (m, 1H), 3.73 – 3.70 (m,1H), 3.65 – 3.60 (m, 2H), 3.56 (dd, J = 10.1, 3.8 Hz, 1H), 3.49 (dd, J =10.3, 9.1 Hz, 1H), 3.21 – 3.10 (m, 2H), 2.05 – 1.98 (m, 2H). 13C NMR (150 MHz, D2O) δ 105.9, 102.6, 102.3, 79.6, 77.7, 75.7, 75.3, 74.6, 74.4, 74.4, 73.5,73.4, 72.8, 72.6, 72.3, 71.8, 69.6, 67.5, 62.6, 62.6, 40.1, 29.1. HRMS (ESI):m / z calcd for C 22 H 42 NO 17 [M+H] + 592.2453, found: 592.2455.

[0088] Example 5:

[0089] A Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen, the structural formula of which is as follows:

[0090] .

[0091] Its preparation method includes the following steps:

[0092] S1. Construction of the disaccharide backbone: Disaccharide PTFAI donor 20 (50 mg, 42 μmol) and Linker acceptor 21 (18 mg, 84 μmol) were dissolved in dry dichloromethane (2.1 mL). Activated 4 Å molecular sieve (420 mg) and triphenylphosphine (95 mg, 0.34 mmol) were added at room temperature. The reaction system was stirred at room temperature for 15 minutes under nitrogen atmosphere. Subsequently, the reaction system was placed at 0 °C and stirred for 15 minutes, followed by slow dropwise addition of TMSI (7.1 μL, 50 μmol). The reaction system was incubated at room temperature for 16 hours. TLC monitoring showed that the donor reaction was complete. Triethylamine was added to adjust the pH of the reaction system to neutral. The mixture was filtered, and the filtrate was diluted with dichloromethane and extracted successively with saturated sodium thiosulfate solution and saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was subjected to silica gel column chromatography (petroleumether / EtOAc). 4:1) Separation and purification yielded colorless syrupy disaccharide 22, namely compound 22 (45 mg, 37 mol, 88%).

[0093] R f = 0.28 (petroleum ether / EtOAc = 2:1). = -84.0 (c 0.6, CHCl3); 1HNMR (400 MHz, CDCl3) δ 8.13 (d, J = 6.9 Hz, 2H), 7.91 (d, J = 7.1 Hz, 2H),7.79 (d, J = 8.5 Hz, 2H), 7.61 (t, J = 7.4 Hz, 1H), 7.55 – 7.43 (m, 6H), 7.36– 7.27 (m, 15H), 7.25 – 7.19 (m, 6H), 7.17 – 7.13 (m, 4H), 7.12 – 7.07 (m,2H), 5.67 (dd, J = 3.3, 1.9 Hz, 1H), 5.63 – 5.53 (m, 2H), 5.49 (d, J = 3.4Hz, 1H), 5.40 (d, J = 1.9 Hz, 1H), 5.06 – 4.96 (m, 3H), 4.87 – 4.80 (m, 2H),4.73 (d, J = 3.6 Hz, 1H, H-1), 4.67 (d, J = 11.3 Hz, 1H), 4.64 – 4.57 (m,2H), 4.56 – 4.51 (m, 2H), 4.50 (d, J = 2.0 Hz, 1H), 4.38 – 4.31 (m, 2H), 4.18(dd, J = 7.4, 4.2 Hz, 1H), 4.02 – 3.94 (m, 2H), 3.84 (dd, J = 10.5, 4.2 Hz,1H), 3.80 – 3.72 (m, 2H), 3.45 – 3.35 (m, 2H), 3.29 – 3.18 (m, 1H), 1.85 –1.76 (m, 2H), 1.03 (d, J = 6.5 Hz, 3H). 13C NMR (100 MHz, CDCl3) δ 166.5,165.2, 165.1, 156.6, 139.2, 138.7, 138.2, 138.1, 137.0, 133.3, 133.2, 132.9,130.1, 130.1, 130.0, 129.8, 129.7, 129.6, 128.6, 128.6, 128.5, 128.5, 128.4,128.3, 128.3, 128.2, 128.0, 127.9, 127.9, 127.7, 127.7, 127.7, 127.6, 127.5,127.4, 127.4, 99.4, 97.9, 79.0, 76.4, 74.1, 73.8, 73.7, 73.6, 73.4, 73.3,73.0, 72.7, 72.4, 71.3, 70.8, 67.6, 66.4, 65.4, 39.6, 29.2, 16.2. HRMS (ESI):m / z calcd for C 73 H 74 NO 18 [M+H] + 1252.4906, found: 1252.4911.

[0094] S2, Global Deprotection: Disaccharide 22 (20 mg, 16.4 μmol) was dissolved in tetrahydrofuran / methanol (3.3 mL, 3:1, v / v), and 1 M NaOH (0.33 mL) was added at 0 °C. The reaction system was stirred at room temperature for 12 hours. TLC monitoring showed that the reaction was complete. The reaction solution was diluted with methanol and then analyzed using Amberlite IR 120 H. + The cation exchange resin was neutralized to pH neutral, and the filtrate was concentrated under reduced pressure after filtration to obtain the crude product for subsequent reactions. The crude product was dissolved in methanol / tetrahydrofuran / water (3.3 mL, 2:1:1, v / v / v), and 20% Pd(OH)₂ / C (20 mg) was added. The reaction was carried out under hydrogen atmosphere for 24 hours. After the reaction, the catalyst was removed by filtration, and the filtrate was freeze-dried to obtain the crude product. The crude product was purified by size exclusion chromatography (BioGel P-2, eluent: 0.05 M NH₄HCO₃ solution). The target fraction was collected and freeze-dried to obtain a white solid, compound 5 (5.3 mg, 12.8 mol, 78%). The proton and carbon spectra of compound 5 are shown below. Figure 9 and Figure 10 As shown, the specific data is as follows:

[0095] = +13.6 (c 0.33, H2O); 1 H NMR (600 MHz, D2O) δ 5.04 (d, J = 0.8Hz, 1H), 4.88 (d, J = 3.7 Hz, 1H), 4.08 – 4.04 (m, 1H), 4.04 – 4.00 (m, 2H), 4.00 – 3.98 (m, 1H), 3.93 (dd, J = 10.4, 3.1 Hz, 1H), 3.89 (dd, J = 10.4, 3.8Hz, 1H), 3.85 – 3.78 (m, 4H), 3.75 – 3.71 (m, 1H), 3.71 – 3.67 (m, 1H), 3.59– 3.53 (m, 1H), 3.05 – 2.91 (m, 2H), 1.97 – 1.87 (m, 2H), 1.18 (d, J = 6.4Hz, 3H). 13 HRMS (ESI): m / z calcdfor C 16 H 32 NO 11 [M+H] + 414.1975, found: 414.1977.

[0096] Experimental example:

[0097] Using the target oligosaccharide molecules modified with aminopropyl linker arms from Examples 1-5, sugar chips were prepared via covalent fixation. The immunogenicity and specificity of each oligosaccharide fragment were systematically evaluated by detecting the binding activity of IgG antibodies to the sugar chains in the sera of eight Helicobacter pylori-infected patients and healthy subjects. The results are as follows: Figure 11 and Figure 12 As shown. Figure 11 and Figure 12 In the diagram, P1 represents patient 1, indicating the serum test result of the first Helicobacter pylori-infected patient; P2-P8 are the same; and P9 represents a healthy subject. The horizontal axis represents compounds 1-5, and the vertical axis represents the immunogenicity and specificity results of each oligosaccharide fragment.

[0098] Depend on Figure 11 and Figure 12 It was found that the trisaccharide (compound 4), tetrasaccharide (compound 3), and hexasaccharide (compound 1) compounds containing the α-d-Glcp-(1→4)-α-d-Galp-(1→7)-α-d,d-Hepp core backbone exhibited strong fluorescence responses in patient serum, while the negative control showed extremely weak signals, demonstrating excellent immunospecificity. Among them, the tetrasaccharide compound formed by introducing a 2,7-branched heptose structure on the basis of the core trisaccharide showed further enhanced immunobinding activity, while the activity decreased when the branch structure continued to extend into the complete O antigen fragment. The above structure-activity relationship reveals that the α-d-Glcp-(1→4)-α-d-Galp-(1→7)-α-d,d-Hepp glycan backbone and its 2,7-branched heptose structure constitute key immunodominant epitopes in the specific humoral immune response induced by Helicobacter pylori infection, while the deep core region and the excessively extended outer region of the O antigen are not the core targets for effectively stimulating and capturing specific antibodies.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen, characterized in that, Its structural formula is: ； ； ； or .

2. The method for preparing Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen according to claim 1, characterized in that, Includes the following steps: A fully protected oligosaccharide backbone was obtained by assembling multiple orthogonally protected monosaccharide building blocks through glycosylation reactions. Specifically, for the construction of 1,2-cis-α-l-fucoside and 1,2-cis-α-d-glucoside bonds, stereospecific construction of the 1,2-cis-α-l-fucoside bond was achieved by utilizing the long-range participation effect of the acyl group at the O-4 position of the glycosyl donor, and stereospecific construction of the 1,2-cis-α-d-glucoside bond was achieved by utilizing the long-range participation effect of the acyl group at the O-6 position of the glycosyl donor. For the 2,7-branched d-glycerol-d-mannohepose backbone, the glycosylation sequence of "O-2 first, then O-7" was followed, and the reaction was carried out in an aromatic solvent. During the construction of the oligosaccharide backbone, functional group modification of the sugar chain structure with significant steric shielding effect was performed, i.e., N-Troc→N-Ac, using the principle of "functional group transformation operation first".

3. The method for preparing Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen as described in claim 2, characterized in that, Specifically, the following steps are included: S1. The monosaccharide acceptor 6 and the trisaccharide thioglycoside donor 7 are activated by N-iodosuccinimide and trifluoromethanesulfonic acid and then subjected to glycosylation to obtain the tetrasaccharide backbone 8. S2. Tetrasaccharide compound 9 was prepared by a one-pot method using a system of zinc powder, acetic anhydride, acetic acid solution and saturated copper sulfate solution to prepare tetrasaccharide skeleton 8. S3. The tetrasaccharide compound 9 was selectively deprotected by DDQ oxidation-hydrolysis to obtain the tetrasaccharide receptor 10. S4. The tetrasaccharide acceptor 10 and the disaccharothioglycoside donor 11 are activated by N-iodosuccinimide and trifluoromethanesulfonic acid to undergo glycosylation reaction to obtain a fully protected hexasaccharide backbone 12. S5. The fully protected hexasaccharide skeleton 12 is subjected to alkaline hydrolysis and catalytic hydrogenation for global deprotection to obtain the target hexasaccharide 1, i.e., compound 1. The monosaccharide receptor 6 has the following structural formula: The structure of the trisaccharoside donor 7 is as follows: The tetrasaccharide skeleton 8 has the following structural formula: The tetrasaccharide compound 9 has the following structural formula: The tetrasaccharide receptor 10 has the following structural formula: The diglucosinolate donor 11 has the following structural formula: The fully protected hexasaccharide backbone 12 has the following structural formula: .

4. The method for preparing Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen as described in claim 3, characterized in that, The tetrasaccharide receptor 10 was globally deprotected by sequential alkaline hydrolysis and catalytic hydrogenation to obtain the target tetrasaccharide compound 2, i.e., compound 2.

5. The method for preparing Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen as described in claim 3, characterized in that, In step S1, the trisaccharide thioglycoside donor 7 is replaced with the monosaccharide thioglycoside donor 13 and activated by N-iodosuccinimide and trifluoromethanesulfonic acid to undergo a glycosylation reaction to obtain disaccharide 14. Steps S2-S5 are repeated to obtain the target tetrasaccharide 3, i.e., compound 3. The monosaccharide thioglycoside donor 13 has the following structural formula: The disaccharide 14 has the following structural formula: .

6. The method for preparing Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen as described in claim 3, characterized in that, In step S1, the monosaccharide acceptor 18 and the disaccharide thioglycoside donor 11 are activated by N-iodosuccinimide and trifluoromethanesulfonic acid to undergo glycosylation reaction to obtain trisaccharide 19; then, the target trisaccharide 4 is obtained by global deprotection through alkaline hydrolysis and catalytic hydrogenation. The monosaccharide receptor 18 has the following structural formula: The structural formula of the trisaccharide 19 is as follows: .

7. The method for preparing Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen as described in claim 3, characterized in that, In step S1, the disaccharide PTFAI donor 20 and Linker acceptor 21 are activated by trimethyliodosilane and triphenoxyphosphine to undergo glycosylation reaction to obtain disaccharide 22; then, the disaccharide is globally deprotected by alkaline hydrolysis and catalytic hydrogenation to obtain the target disaccharide 5, i.e., compound 5. The disaccharide PTFAI donor 20 has the following structural formula: The Linker receptor 21 has the following structural formula: The disaccharide 22 has the following structural formula: .

8. The method for preparing Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen as described in claim 2, characterized in that, The reducing end of the Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen is modified with an aminopropyl linker.

9. The method for preparing Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen as described in claim 2, characterized in that, The purity of the Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen is ≥95%.

10. The application of the Helicobacter pylori lipopolysaccharide-associated oligosaccharide antigen of claim 1 in the preparation of sugar chips for primary screening of Helicobacter pylori infection-related activities or in the preparation of vaccines using mucin.

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