Serotype 10a oligosaccharide compounds of streptococcus pneumoniae and their use in the preparation of a streptococcus pneumoniae vaccine

Abstract

The application discloses a Streptococcus pneumoniae 10A serotype oligosaccharide compound and application thereof in preparation of a Streptococcus pneumoniae vaccine, and belongs to the medical field. The application provides a new type of Streptococcus pneumoniae 10A serotype oligosaccharide compound with a clear structure, the oligosaccharide compound is fixed on a chip surface to prepare a synthetic oligosaccharide chip, five oligosaccharide compounds with strong antigenicity are obtained by screening with antisera, and the oligosaccharide compounds are further conjugated with a carrier protein CRM197 to obtain glycoprotein conjugates, and the oligosaccharide compounds with good immunogenicity are obtained through animal immunization experiments and antibody detection, and are further used for preparation of a Streptococcus pneumoniae conjugate vaccine or a high-valence Streptococcus pneumoniae vaccine. The application solves the problems of high structural heterogeneity of natural extraction polysaccharide antigens, difficulty in quality control, insufficient immunogenicity of part of the antigens and low fermentation production efficiency, and has a good application prospect in upgrading of the Streptococcus pneumoniae vaccine and development of a new type of sugar vaccine.

Description

Technical Field

[0001] This invention specifically relates to oligosaccharide compounds of Streptococcus pneumoniae serotype 10A and their application in the preparation of Streptococcus pneumoniae vaccines, belonging to the pharmaceutical field. Background Technology

[0002] Against the backdrop of increasing antibiotic resistance, polysaccharide vaccines and polysaccharide conjugate vaccines prepared from pathogenic glycan structures on the bacterial surface, especially capsular polysaccharides, have become important means of preventing related bacterial infections. These vaccines have been widely used to prevent infectious diseases caused by pathogens such as Haemophilus influenzae type b, Streptococcus pneumoniae, Neisseria meningitidis, and Salmonella typhi, and have significantly reduced the disease burden associated with these pathogens (Mettu et al., J. Biomed. Sci. 2020, 27, 9.). Among them, Streptococcus pneumoniae vaccines are one of the most widely used and clinically in-demand types of bacterial glycan vaccines.

[0003] With the development of glycovaccine technology, related products have undergone continuous iteration from natural polysaccharide vaccines and glycoprotein conjugate vaccines to glycoengineered vaccines (Zou et al., Glycoscience & Therapy 2026, 2(2), 100039.). Pneumococcal polysaccharide vaccines have been developed to 23-valent products, and pneumococcal polysaccharide conjugate vaccines suitable for infants and children have also been developed in different valence types such as 7, 10, 13, 15, 20, and 21 valents. However, most of the glycoantigens in existing pneumococcal and other vaccines are derived from natural capsular polysaccharides extracted after bacterial fermentation. Natural polysaccharide antigens usually have problems such as complex structural composition, high difficulty in batch consistency control, low fermentation yield of some serotypes, complex purification processes, and insufficient immunogenicity of some antigens. These factors not only affect the quality control and process stability of existing glycovaccines but also limit the further development of high-valent vaccines and novel bacterial glycovaccines. (Li et al., Carbohydr. Polym. Technol. Appl. 2025, 9, 100733.).

[0004] Streptococcus pneumoniae serotype 10A is one of the serotypes of interest in the design of high-valent pneumococcal vaccines and is associated with invasive pneumococcal disease (Demirdal et al., Expert Rev. Anti Infect. Ther. 2021, 19(7), 927-944.). However, the capsular polysaccharide of this serotype is characterized by its complex structure, high degree of branching, and difficulty in determining its antigenic epitopes, which limits the direct optimization of antigenic structure and the study of immunomodulatory activity based on natural polysaccharides. Summary of the Invention

[0005] Technical issues: The technical problem to be solved by this invention is that the existing Streptococcus pneumoniae 10A serotype vaccine antigen is mainly derived from natural capsular polysaccharide extracts, which have problems such as heterogeneous structural composition, unclear key antigenic epitopes, difficulty in quality control, insufficient immunogenicity of some antigens, and limited fermentation production efficiency, thus limiting its application in the development of Streptococcus pneumoniae vaccines and the upgrading of high-priced vaccines.

[0006] This invention provides oligosaccharide compounds with simple and well-defined structures, and the preparation of their glycoprotein conjugates, and, combined with immunogenicity evaluation, provides a technical basis for antigen optimization of Streptococcus pneumoniae 10A serotype vaccine and the development of Streptococcus pneumoniae glycoprotein vaccines.

[0007] Technical solution: To address the aforementioned technical problems, this invention provides several oligosaccharide compounds with well-defined structures. Oligosaccharide fragments are immobilized on a chip surface to prepare an oligosaccharide chip. Highly antigenic fragments are screened using antiserum. Furthermore, the screened fragments are conjugated with a carrier protein to prepare glycoprotein conjugates. Effective oligosaccharide fragments with good antigenicity and immunogenicity are screened through animal immunization experiments, antibody titer detection, and antigen recognition analysis. This provides new antigenic substances and technical pathways for the preparation of Streptococcus pneumoniae 10A serotype vaccines and related Streptococcus pneumoniae glycosaminoglycan vaccines.

[0008] The first objective of this invention is to provide the use of an oligosaccharide compound of Streptococcus pneumoniae serotype 10A, its free base, pharmaceutically acceptable salt, zwitterion, or lyophilized powder, in the preparation of a Streptococcus pneumoniae vaccine, wherein the oligosaccharide compound is selected from any one or more of the following:

[0009] Where Z is an empty key or ; R1, R2, and R3 are each independently selected from H, ; R4 is independently selected from H, ; M is either Na or K; Linker is a connecting arm selected from -(CH2)n-NH2, -(CH2)n-SH, azide-based connecting arms, alkynyl-based connecting arms, maleimide reactive connecting arms, or their derivatives; n is 2-40.

[0010] In one embodiment of the present invention, the oligosaccharide compound may further be selected from any one or more of the following: .

[0011] In one embodiment of the present invention, when Z is an empty bond, the structure is as shown in formula (A-)1 above.

[0012] In one embodiment of the present invention, the oligosaccharide compound may be selected from any one or more of the following: .

[0013] In one embodiment of the invention, the pharmaceutically acceptable salt form includes, but is not limited to, hydrochloride, acetate, phosphate, citrate, lactate, tartrate, or sodium, potassium, and ammonium salts.

[0014] A second object of the present invention is to provide an oligosaccharide compound for the preparation of a pneumococcal conjugate vaccine; said compound having the structure shown in formula (A) or formula (B): , The definitions of Z, R1, R2, M, and n are the same as above.

[0015] A third object of the present invention is to provide a sugar chip, comprising a chip matrix and the aforementioned oligosaccharide compound fixed to the surface of the chip matrix.

[0016] In one embodiment of the present invention, the chip matrix may be an NHS ester-activated glass slide, an epoxy-based glass slide, an aldehyde-based glass slide, a carboxyl-based glass slide, a maleimide-modified glass slide, or other solid-phase materials that can undergo covalent reactions with the connecting arms.

[0017] In one embodiment of the present invention, the oligosaccharide compound is fixed to the chip surface via its terminal linker arm. The linker arm includes amino, thiol, azide, alkynyl, or other reactive groups; wherein, the amino linker arm can be coupled to an NHS ester, aldehyde, or carboxyl activated surface, and the thiol linker arm can be coupled to a maleimide modified surface, thereby arranging different oligosaccharide fragments on the chip surface in a comparable manner.

[0018] In one embodiment of the present invention, the sugar chip is a microarray chip formed by fixing oligosaccharide fragments to the chip surface via their connecting arms. The obtained oligosaccharide chip is incubated with Streptococcus pneumoniae 10A serotype-associated antiserum; labeled secondary antibody is added for detection; and oligosaccharide fragments with antigenicity are screened based on the detection signal.

[0019] In one embodiment of the present invention, the oligosaccharide compound is spotted onto the chip surface in the form of a concentration gradient, with a spotting concentration of 0.01-10 mM, preferably 2 mM and 5 mM; each oligosaccharide compound is set with 2-3 replicate spots, and spotting buffer, unrelated oligosaccharide, unrelated natural capsular polysaccharide, carrier protein, natural Streptococcus pneumoniae 10A serotype capsular polysaccharide or its polysaccharide-protein conjugate are set as negative or positive controls.

[0020] In one embodiment of the present invention, the oligosaccharide compound is dissolved in 10-100 mM phosphate buffer at pH 8.0-9.0, preferably 50 mM phosphate buffer at pH 8.5. After spotting, the chip is incubated overnight at 20-30 °C and 50%-70% humidity, preferably 25 °C and 65% humidity, to ensure sufficient coupling of the oligosaccharide compound with the chip surface; subsequently, the chip is quenched and blocked with ethanolamine, sodium phosphate, Tris, BSA, or a combination thereof to reduce nonspecific binding.

[0021] In one embodiment of the present invention, the antiserum is an antiserum obtained from rabbit immunization with purified polysaccharide of Streptococcus pneumoniae serotype 10A capsular polysaccharide, an antiserum obtained from rabbit immunization with a 10A serotype polysaccharide conjugate, or a commercially available Streptococcus pneumoniae antiserum (rabbit) - serotype 10A. The antiserum can be diluted at a ratio of 1:10 to 1:1000, preferably at a ratio of 1:50, and then incubated with the oligosaccharide chip.

[0022] In one embodiment of the present invention, a fluorescently labeled secondary antibody is added after serum incubation for detection. The fluorescently labeled secondary antibody includes anti-rabbit, anti-mouse, or anti-human IgG antibodies labeled with Cy3, FITC, Alexa Fluor, or other fluorescent dyes, and may also detect IgM, IgA, or IgG subtype antibodies as needed; the secondary antibody dilution ratio is 1:30-1:1000, preferably 1:400.

[0023] In one embodiment of the present invention, by comparing the fluorescence signals of oligosaccharide fragments with different chain lengths, different terminal structures, whether they contain phosphodiester bonds, whether they contain branched triadic structures, and whether they contain furanylgalactose residues, the dominant or minimal antigenic epitopes in the capsular polysaccharide of Streptococcus pneumoniae serotype 10A can be determined. The five highly antigenic oligosaccharide fragments obtained through glycoarray screening can be further used for the preparation of glycoprotein conjugates and the evaluation of animal immunogenicity.

[0024] In one embodiment of the present invention, the oligosaccharide compound is preferably a trisaccharide 3a, a tetrasaccharide 4c, a pentasaccharide 5b, a hexasaccharide 6a, or a heptasaccharide 7.

[0025] .

[0026] A fourth object of the present invention is to provide a glycoprotein conjugate formed by conjugation of a carrier protein with a Linker structure in the oligosaccharide compound.

[0027] In one embodiment of the present invention, the carrier protein in the glycoprotein conjugate includes CRM197, tetanus toxoid, diphtheria toxoid, keyhole hemocyanin, bovine serum albumin, meningococcal outer membrane protein complex or its modifications, preferably CRM197.

[0028] In one embodiment of the present invention, the immunogenicity screening of glycoprotein conjugates includes immunizing experimental animals with glycoprotein conjugates corresponding to different oligosaccharide fragments, respectively, after preparation with adjuvants, and collecting serum after primary immunization and two booster immunizations. The adjuvant may be aluminum hydroxide, aluminum phosphate, emulsion adjuvants, or combinations thereof. Immunization methods include subcutaneous, intramuscular, or intraperitoneal injection; immunization subjects include mice, rabbits, or other animal models suitable for vaccine evaluation, preferably New Zealand rabbits, administered subcutaneously, using Freund's adjuvant to enhance the immune response.

[0029] In one embodiment of the present invention, the immunogenicity screening indicators include, but are not limited to: antibody titer against natural 10A serotype capsular polysaccharide, antibody titer against 10A polysaccharide-protein conjugates, antibody binding ability to intact 10A serotype Streptococcus pneumoniae, antibody cross-reactivity to different synthetic oligosaccharide fragments, antibody affinity, IgG subtype distribution, complement deposition ability, and opsonization and phagocytic bactericidal activity.

[0030] In one embodiment of the present invention, immune serum can be comprehensively evaluated by ELISA, oligosaccharide microarray, flow cytometry, immunofluorescence, competitive inhibition assay, complement-dependent bactericidal assay, or opsonization-phagocytosis-bactericidal assay. Preferred highly immunogenic glycoprotein conjugates should be able to induce high levels of specific IgG antibodies, and the induced antibodies should be able to recognize natural 10A capsular polysaccharide or 10A serotype bacteria, and have low nonspecific background and good functional activity.

[0031] In one embodiment of the present invention, the glycoprotein conjugate may specifically be: trisaccharide glycoprotein 3a-CRM197, pentasaccharide glycoprotein 5b-CRM197, hexasaccharide glycoprotein 6a-CRM197, and heptasaccharide glycoprotein 7-CRM197; the corresponding structures are shown below: , Where x can be selected from 2 to 20; In one embodiment of the present invention, four chemically synthesized oligosaccharide fragments of pneumococcal serotype 10A capsular polysaccharide with good immunogenic activity were screened: trisaccharide 3a, pentasaccharide 5b, hexasaccharide 6a, and heptasaccharide 7. These fragments can be used for the preparation of pneumococcal conjugate vaccines and for constructing an antigen optimization platform. This platform provides structurally controllable key serotype oligosaccharide antigens through chemical synthesis and provides a mature multivalent combination basis through existing polysaccharide conjugate vaccine processes, thereby taking into account precise antigen definition, production controllability, quality consistency, and clinical translation feasibility.

[0032] A fifth objective of the present invention is to provide a Streptococcus pneumoniae 10A serotype vaccine, the vaccine comprising the above-mentioned Streptococcus pneumoniae 10A serotype oligosaccharide compound or the above-mentioned glycoprotein conjugate.

[0033] In one embodiment of the present invention, the vaccine includes a novel pneumococcal conjugate vaccine or a high-valent pneumococcal conjugate vaccine for the prevention of pneumococcal infection.

[0034] This invention is based on oligosaccharide fragments of capsular polysaccharide from Streptococcus pneumoniae serotype 10A, combined with immunological studies to screen effective sugar fragments with antigenicity and immunogenicity. This is of great significance for elucidating the key antigenic epitopes of this serotype capsular polysaccharide, improving the controllability of antigen quality, and developing novel Streptococcus pneumoniae sugar vaccines.

[0035] This invention utilizes chemically synthesized effective oligosaccharide fragments from the capsular polysaccharide of Streptococcus pneumoniae 10A serotype for the preparation of glycoprotein conjugates and Streptococcus pneumoniae vaccines. This helps to solve problems such as the heterogeneity of natural polysaccharide antigen structure, difficulty in quality control, and insufficient functional optimization of some serotype antigens. It has good application prospects in the upgrading of Streptococcus pneumoniae vaccines and the development of novel bacterial glycosaminoglycan vaccines.

[0036] This invention has at least one of the following beneficial effects: (1) Based on the hepta-saccharide repeating unit of the capsular polysaccharide of Streptococcus pneumoniae 10A serotype, this invention obtains oligosaccharide fragments with well-defined structure, uniform composition and linker arms through chemical synthesis. This can avoid problems such as uneven chain length distribution, impurity residue and batch-to-batch structural differences in natural polysaccharide extracts, which is beneficial for subsequent antigen quality control and standardized preparation.

[0037] (2) The oligosaccharide fragment library constructed in this invention covers key structural factors such as different chain lengths, different terminal structures, phosphodiester bonds, branched tri-antenna structures, and furanylgalactose residues. It can be used to analyze the dominant or minimal antigenic epitopes of the capsular polysaccharide of Streptococcus pneumoniae 10A serological type at the molecular level, providing a basis for antigen structure optimization.

[0038] (3) The present invention fixes the synthetic oligosaccharide fragments on the chip surface and rapidly compares the antigenicity of different oligosaccharide fragments through antiserum screening. The screening process has low sample consumption, high throughput and good repeatability, and is suitable for systematic epitope analysis of complex capsular polysaccharide antigens.

[0039] (4) In this invention, highly antigenic oligosaccharide fragments are conjugated with carrier proteins to obtain glycoprotein conjugates with well-defined structures. Candidates with good immunogenicity are screened by animal immunization and antibody titer detection. Among them, trisaccharide glycoprotein 3a-CRM197, pentasaccharide glycoprotein 5b-CRM197, hexasaccharide glycoprotein 6a-CRM197 and heptasaccharide glycoprotein 7-CRM197 can be used as preferred glycoprotein conjugate candidates.

[0040] (5) This invention can reduce the dependence on fermentation and extraction of natural polysaccharides of Streptococcus pneumoniae 10A serotype, improve the controllability, comparability and traceability of key antigens, and has promotional value for the development of high-priced Streptococcus pneumoniae sugar vaccines and other bacterial sugar vaccines. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the technical route of the present invention, showing the process of chemically synthesizing oligosaccharide fragment library, screening sugar chips, preparing glycoprotein conjugates, animal immunization, and evaluating immunogenicity.

[0042] Figure 2 This is a schematic diagram of the structure of the 15 oligosaccharide compounds of the present invention.

[0043] Figure 3 This is a synthetic route diagram for the key intermediates in the preparation of oligosaccharide compounds of this invention.

[0044] Figure 4 This is a synthetic route diagram for oligosaccharide compounds 3a, 4c, 5b, 6a, and 7 of the present invention.

[0045] Figure 5 This is a synthetic route diagram for oligosaccharide compounds 2a, 2b, 2c, 3b, 3c, 3d, 4a, 4b, 5a, and 6b of the present invention.

[0046] Figure 6 The diagram shows the oligosaccharide chip spotting mode (A), the antiserum incubation scan (B), and the average fluorescence quantitative result (C).

[0047] Figure 7 A schematic diagram of the preparation route for the five glycoprotein conjugates (A) and SDS-PAGE characterization (B).

[0048] Figure 8 Schematic diagram of ELISA detection results of IgG antibody titer in rabbit antiserum after immunization with five glycoprotein conjugates: Coating image of purified polysaccharide of Streptococcus pneumoniae 10A serotype (A), Coating image of polysaccharide-protein conjugate of Streptococcus pneumoniae 10A serotype (B).

[0049] Figure 9 To analyze the cross-recognition ability of five glycoprotein conjugate immune antisera on different synthetic oligosaccharide fragments using a glycan microarray. Detailed Implementation

[0050] The present invention will be further illustrated below with reference to the embodiments. It should be understood that the following embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Any equivalent substitutions or conventional adjustments made under the concept of the present invention to the oligosaccharide fragment chain length, linker arm type, carrier protein, adjuvant, administration method or multivalent vaccine combination method should be included within the scope of protection of the present invention.

[0051] Unless otherwise stated, the chemical reagents, solvents, carrier proteins, adjuvants, chip matrices and detection antibodies used in this invention can all be from conventional commercial sources in the art; the reaction products can be structurally or compositionally confirmed by nuclear magnetic resonance, mass spectrometry, infrared spectroscopy, optical rotation, HPLC, gel electrophoresis, size exclusion chromatography or sugar content determination.

[0052] Regarding the NMR data analysis in the following embodiments, for compounds containing multiple sugar units, each sugar unit is numbered sequentially according to the connection order of the sugar chains as sugar a, sugar b, sugar c, etc. Taking complete compound 7 as an example, the numbering method of its sugar units is as follows:

[0053] In NMR analysis, the hydrogen at position 1 of the α-sugar is labeled "1a-H". The sugar units in other oligosaccharide or polysaccharide compounds follow the same numbering rule, and so on.

[0054] Example 1: Synthesis of key intermediates from a library of capsular polysaccharide oligosaccharide fragments from Streptococcus pneumoniae serotype 10A. The following synthesis process is provided for some of the substrates: Compound 1*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl-2-O-acetyl-4,6-O-benzylmethylacetal-3-O-(2-naphthylmethyl)-β-D-galactopyranose Starting with commercially available β-D-galactospentaacetate, an acetyl-mediated thioglycosylation reaction was carried out with ethanethiol under the catalysis of boron trifluoride diethyl ether, converting the terminal acetoxy group to an ethylthio group to obtain the corresponding ethylthiogalactoside intermediate. Subsequently, after deacetylation in a sodium methoxide / methanol environment, benzaldehyde dimethyl acetal and p-toluenesulfonic acid were used to protect the O4,6-benzylidene groups, yielding a 4,6-O-benzylidene-protected galactoside intermediate (see literature report: Zou Xiaopeng, Doctoral Dissertation, Jiangnan University, 2020). Based on this, a tin acetal intermediate was first prepared using a dibutyltin oxide-mediated regioselective protection method. The glycosyl intermediate was dissolved in anhydrous methanol, and 1.2 molar equivalents of dibutyltin oxide were added. The mixture was heated under nitrogen protection and refluxed for 6 h. After the reaction, the methanol was removed by concentration under reduced pressure. The residue was co-distilled three times with anhydrous toluene to thoroughly remove residual methanol and water, yielding the corresponding tin acetal intermediate. The aforementioned tin acetal intermediate was dissolved in anhydrous N,N-dimethylformamide, followed by the sequential addition of 1.3 molar equivalents of 2-bromomethylnaphthalene and 1.3 molar equivalents of cesium fluoride. The reaction was carried out under nitrogen protection at 50 °C for 12 h with stirring to obtain a C3-2-naphthyl-protected glycosyl intermediate. Subsequently, the intermediate was dissolved in anhydrous pyridine, and acetic anhydride (5.0 molar equivalents relative to the substrate) and a catalytic amount of 4-dimethylaminopyridine were added. The reaction was carried out at room temperature with stirring for 6 h to acetylate the free hydroxyl group at the C2 position, yielding the corresponding thioglycoside glycosyl donor. Finally, the thioglycoside glycosyl donor, 1.2 molar equivalents of the acceptor N-benzyl-N-benzyloxycarbonyl-5-aminopentyl-1-ol, and activated 4 Å molecular sieve were added to a dry reaction vessel. Anhydrous dichloromethane was added under nitrogen protection for dissolution, and the mixture was stirred at room temperature for 30 min before cooling the reaction system to 0 °C. Subsequently, 1.3 molar equivalents of N-iodosuccinimide and 0.1 molar equivalents of trimethylsilyltrifluoromethanesulfonate were added sequentially, and the reaction was continued to be stirred at 0 °C for 5 h. The reaction progress was monitored by thin-layer chromatography. After the glycosyl donor was substantially consumed, triethylamine was added to quench the reaction. The reaction mixture was filtered through diatomaceous earth to remove the molecular sieve. The filtrate was diluted with dichloromethane and washed sequentially with saturated sodium thiosulfate aqueous solution and saturated sodium bicarbonate aqueous solution. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to prepare the target compound 1*. [α] 25 D = +16.05° ( c = 0.1,CHCl3); IR νmax (film) 2924, 1741, 1697, 1454, 1421, 1368, 1275, 1259, 1235,1081, 1055, 1003, 821, 765, 758, 751, 698 cm-1 ; 1 H NMR (400 MHz, CDCl3) δ 7.90- 7.73 (m, 4H, Ar-H), 7.60 - 7.44 (m, 5H, Ar-H), 7.43 - 7.15 (m, 13H, Ar-H),5.50 (s, 1H, Ar-CH), 5.44 - 5.37 (m, 1H, 2b-H), 5.19 (d, J = 8.8 Hz, 2H,Linker-CH2), 4.91 - 4.77 (m, 2H, Ar-CH2), 4.51 (t, J = 3.5 Hz, 2H, Linker-CH2),4.38 (t, J = 8.2 Hz, 1H, 1b-H), 4.31 (d, J = 12.3 Hz, 1H, 6b-CH2), 4.21 (d, J =3.5 Hz, 1H, 4b-H), 4.03 (dd, J = 12.4, 1.8 Hz, 1H, 6b-CH2), 3.86 (d, J = 7.1Hz, 1H, Linker-CH2), 3.64 (dd, J = 10.1, 3.5 Hz, 1H, 3b-H), 3.42 (d, J = 9.9Hz, 1H, Linker-CH2), 3.34 (s, 1H, 5b-H), 3.24 (d, J = 29.8 Hz, 2H, Linker-CH2),2.12 - 1.92 (m, 3H, Ac-CH3), 1.60 - 1.48 (m, 4H, Linker-CH2), 1.39 - 1.28 (m,2H, Linker-CH2); 13C NMR (101 MHz, CDCl3) δ 169.4, 137.9, 137.7, 135.6, 133.2,133.1, 129.0, 128.53, 128.47, 128.20, 128.16, 127.9, 127.83, 127.75, 127.3,126.5, 126.4, 126.2, 126.0, 125.6, 101.3 (1b-C), 101.1, 73.3, 71.3, 70.1,69.1, 67.1, 66.6, 29.2, 23.1, 21.0; HR-ESI-MS (m / z): calcd for C 46 H 49 NO9Na + (M+Na) + : 782.3300, found: 782.3321. Compound 3*: N-Phenylacetyl trifluoroacetylimide 2,3,6-tri- O -benzyl-5- O -(2-Naphthylmethyl)-D-galactofuranose Starting with commercially available D-galactose, it was dissolved in allyl alcohol and tetrahydrofuran. 1.5 molar equivalents of anhydrous ferric chloride and 1.0 molar equivalent of anhydrous calcium chloride were added, and the mixture was reacted at room temperature for 48 h to obtain a terminally allyl-substituted D-furan-galactose intermediate. Subsequently, using 10.0 molar equivalents of 2,2-dimethoxypropane as a ketal reagent, and with the catalytic action of p-toluenesulfonic acid, the mixture was reacted at room temperature for 5 h to protect the hydroxyl groups at the O4 and O6 positions with propylene oxide. The resulting intermediate was then reacted at 0 °C with 4.0 molar equivalents of sodium hydride and 4.0 molar equivalents of benzyl bromide, and the mixture was raised to room temperature for 4 h to benzylate the free hydroxyl groups. Finally, it was treated with 66% acetic acid aqueous solution at 60 °C for 3 h to remove the propylene oxide protecting groups at the O4 and O6 positions. The obtained diol intermediate was refluxed with 0.7 molar equivalents of bis(tri-n-butyltin) oxide in anhydrous toluene for 6 h. Then, 2.0 molar equivalents of benzyl bromide and 0.2 molar equivalents of tetrabutylammonium iodide were added, and the mixture was refluxed for 12 h to selectively protect the C6 hydroxyl group. The intermediate was then dissolved in anhydrous N,N-dimethylformamide, and 4.0 molar equivalents of sodium hydride and 2.0 molar equivalents of 2-bromomethylnaphthalene were added sequentially at 0 °C. The mixture was then reacted at room temperature for 3 h to introduce a 2-naphthylmethyl protecting group to the remaining hydroxyl group. Finally, the fully protected intermediate was dissolved in a methanol / dichloromethane mixture, and 0.25 molar equivalents of palladium chloride were added. The mixture was reacted at room temperature for 10 h to remove the terminal allyl group, yielding a hemiacetal intermediate. Subsequently, the target furan galactose donor compound 3* was obtained by reacting at room temperature for 8 h with 20.0 molar equivalents of anhydrous potassium carbonate and 5.0 molar equivalents of N-phenyltrifluoroacetylimide chloride, followed by post-treatment and purification by silica gel column chromatography. 1 H NMR (600 MHz, CDCl3) δ 7.89 - 7.69 (m, 4H, Ar-H), 7.53 - 7.41 (m, 3H, Ar-H), 7.39 - 6.97 (m, 20H, Ar-H), 4.88 - 4.77 (m,2H, Ar-CH2), 4.69 - 4.61 (m, 2H, Ar-CH2), 4.54 (d, J = 11.7 Hz, 1H, Ar-CH2),4.49 (s, 2H, Ar-CH2), 4.33 (t, J = 7.3 Hz, 1H, Ar-CH2), 4.28 (d, J = 11.5 Hz,1H, 2e-H), 4.22 (s, 1H, 3e-H), 4.16 - 4.11 (m, 1H, 4e-H), 3.76 (d, J= 5.5 Hz, 1H, 5e-H), 3.65 (t, J = 2.5 Hz, 2H, 6e-CH2); 13 C NMR (151 MHz, CDCl3) δ 144.0,138.1, 137.8, 137.4, 136.0, 133.2, 133.0, 129.4, 128.6, 128.5, 128.4, 128.3,128.1, 128.0, 127.67, 127.66, 127.6, 126.9, 126.3, 126.0, 125.8, 124.0,120.4, 119.5, 96.9, 84.2, 82.1, 80.3, 77.9, 73.43, 73.36, 73.3, 72.4, 70.1, 31.5, 30.1, 29.7, 22.7, 14.1. Compound 5*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl-2-O-acetyl-4,6-O-benzylmethylacetal-β-D-galactopyranose-(1→4)-2-N-acetyl-6-O-acetyl-3-O-acetylpropionyl-2-deoxy-β-D-galactopyranose

[0055] Starting with commercially available β-D-galactosamine pentaacetate (purchased from Sinopharm Chemical Reagent Co., Ltd.), 1.5 molar equivalents of N-benzyl-N-benzyloxycarbonyl-5-aminopentyl-1-ol were dissolved in anhydrous dichloromethane. 1.0 molar equivalents of ytterbium trifluoromethanesulfonate and activated 4 Å molecular sieve were added. The mixture was refluxed at 40 °C for 24 h under nitrogen protection, yielding a fully acetyl-protected glycoside intermediate via acetyl-ortho-alcohol glycosylation. This intermediate was dissolved in anhydrous methanol, and 0.5 molar equivalents of sodium methoxide were added. The reaction was carried out at room temperature for 3 h to remove the acetyl protecting group. The resulting intermediate was further reacted with 2.0 molar equivalents of benzaldehyde dimethyl acetal and 0.15 molar equivalents of p-toluenesulfonic acid in anhydrous DMF at 60 °C for 14 h to form benzyl derivative protecting groups at the O4 and O6 positions. Subsequently, the obtained intermediate was dissolved in anhydrous dichloromethane, and 3.0 molar equivalents of levulinic acid, 2.0 molar equivalents of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and a catalytic amount of 4-dimethylaminopyridine were added. The reaction was carried out at room temperature for 10 h to protect the C3 hydroxyl group by levulinization. The above intermediate was then placed in an 80% aqueous acetic acid solution and reacted at 60 °C for 12 h to remove the benzylidene protecting groups at the O4 and O6 positions. Finally, the obtained diol intermediate was dissolved in anhydrous dichloromethane, and 1.2 molar equivalents of tert-butyldimethylchlorosilane and 4.0 molar equivalents of imidazole were added. The reaction was carried out at 0 °C for 30 min, then raised to room temperature and continued for 12 h to selectively protect the C6 hydroxyl group with a tert-butyldimethylsilyl group, yielding the corresponding acetaminogalactosyl acceptor. A 1.0 molar equivalent of ethylthioglycoside donor and a 1.2 molar equivalent of acetylgalactosyl glycosyl acceptor were dissolved in anhydrous dichloromethane, and activated 4 Å molecular sieves were added. The mixture was stirred for 30 min under nitrogen protection. Subsequently, a 1.5 molar equivalent of N-iodosuccinimide and a 0.1 molar equivalent of trimethylsilyltrifluoromethanesulfonate were added, and the mixture was reacted at room temperature for 5 h to obtain a β-configuration disaccharide intermediate via glycosylation. The obtained disaccharide intermediate was dissolved in a mixed solution of acetic acid / tetrahydrofuran / water in a volume ratio of 3:1:1, and reacted at room temperature for 15 h to selectively remove the tert-butyldimethylsilyl protecting group, yielding the corresponding free hydroxyl intermediate. Subsequently, this intermediate was dissolved in anhydrous pyridine, and a 5.0 molar equivalent of acetic anhydride and a catalytic amount of 4-dimethylaminopyridine were added. The mixture was reacted at room temperature for 8 h to acetylate and protect the exposed hydroxyl group. Finally, the obtained acetylated intermediate was dissolved in a dichloromethane / methanol mixed solvent, and 3.0 molar equivalents of hydrazine acetate were added. The mixture was reacted at room temperature for 3 h to selectively remove the acetylpropionyl protecting group, yielding the target disaccharide compound 5* containing a free hydroxyl group. 1H NMR (600 MHz, CDCl3) δ 7.86 – 7.71 (m, 4H, Ar-H), 7.56 –7.42 (m, 5H, Ar-H), 7.41 – 7.15 (m, 13H, Ar-H), 6.05 (s, 1H, 2a-NH), 5.47 –5.35 (m, 2H, Ar-CH, 2b-H), 5.21 – 5.13 (m, 2H, Linker-CH2), 4.84 – 4.73 (m,3H, 1b-H, Linker-CH2), 4.60 – 4.42 (m, 3H, Ar-CH2, 6a-CH2), 4.31 (dd, J = 12.0,7.3 Hz, 1H, 6a-CH2), 4.26 – 4.18 (m, 2H, 1a-H, 6b-CH2), 4.11 (d, J = 3.5 Hz,1H, 3b-H), 3.99 – 3.94 (m, 2H, 6b-CH2), 3.86 (s, 1H, 5a-H), 3.72 (d, J = 28.5Hz, 2H, 2a-H, 5b-H), 3.66 – 3.56 (m, 3H, 3a-H, 4a-H, 4b-H), 3.42 – 3.13 (m,4H, Linker-CH2), 2.17 (d, J = 6.3 Hz, 3H, Ac-CH3), 2.01 (d, J = 8.6 Hz, 6H, Ac-CH3, NHAc-CH3), 1.54 (s, 4H, Linker-CH2), 1.33 (s, 2H, Linker-CH2); 13C NMR (151MHz, CDCl3) δ 171.0, 169.8, 137.8, 136.7, 135.6, 133.1, 133.0, 129.1, 128.6,128.5, 128.24, 128.18, 128.0, 127.9, 127.7, 127.4, 127.3, 126.6, 126.4,126.2, 126.0, 125.7, 102.0 (1b-C), 101.4, 100.2 (1a-C), 75.0, 73.3, 72.5,71.5, 70.5, 69.0, 68.3, 67.2, 66.3, 64.2, 54.9, 50.4, 47.3, 46.1, 29.7, 28.7,27.9, 27.0, 23.2, 21.2, 21.0; MALDI-TOF (m / z): calcd for C 56 H 64 N2O 15 Na + (M+Na) + :1027.4199, found: 1027.4112. Compound 9*: Ethio-2,3,5,6-tetra-O-benzyl-β-D-galactofuranose Starting with commercially available D-galactose, it was dissolved in anhydrous N,N-dimethylformamide and cooled to 0 °C under nitrogen protection. 6.0 molar equivalents of sodium hydride were added in portions, and the mixture was stirred for 30 min. Then, 6.0 molar equivalents of benzyl bromide and a catalytic amount of potassium iodide were added, followed by reaction at room temperature for 5 h. After the reaction was complete, methanol was added at 0 °C for quenching. The mixture was then purified by extraction, drying, concentration, and silica gel column chromatography to obtain a fully benzyl-protected furan-type galactose intermediate. This intermediate was dissolved in an acetic acid / water mixture, and 0.10 molar equivalents of concentrated sulfuric acid were added. The mixture was reacted at 80 °C for 3 h to selectively remove the terminal benzyl group, yielding the corresponding hemiacetal intermediate. Subsequently, the hemiacetal intermediate was dissolved in anhydrous pyridine, and 5.0 molar equivalents of acetic anhydride were added. The mixture was reacted at room temperature for 8 h to acetylate the terminal hydroxyl group. After the reaction was complete, the mixture was concentrated, extracted, and purified by silica gel column chromatography to obtain the acetylated furan-type galactose intermediate. Finally, the above-mentioned terminal acetylated intermediate was dissolved in anhydrous dichloromethane, cooled to 0 °C under nitrogen protection, and 2.0 molar equivalents of ethanethiol and 2.0 molar equivalents of boron trifluoride diethyl ether complex were added. The reaction was then brought to room temperature for 6 h. After the reaction was complete, triethylamine or a saturated sodium bicarbonate aqueous solution was added to quench the reaction. The resulting product was purified by extraction, washing, drying, concentration, and silica gel column chromatography to obtain the furan-type galactosidoside donor compound 9*. [α] 25 D = -97.73° ( c = 1.0, CHCl3); IR νmax (film) 3063, 3030,2867, 1606, 1497, 1454, 1361, 1307, 1263, 1207, 1095, 1073, 1028, 911, 789,736, 697, 608, 457cm -1 ; 1 H NMR (600 MHz, CDCl3) δ 7.42 - 7.14 (m, 20H, Ar-H), 5.40 (d, J = 2.6 Hz, 1H, 1d-H), 4.71 (d, J = 11.8 Hz, 1H, Ar-CH2), 4.60 (d, J =11.8 Hz, 1H, Ar-CH2), 4.56 - 4.46 (m, 3H, Ar-CH2, 2d-H), 4.47 - 4.40 (m, 2H, Ar-CH2), 4.30 - 4.22 (m, 2H, Ar-CH2), 4.07 - 4.00 (m, 1H, 4d-H), 3.93 (t,J =3.0 Hz, 1H, 3d-H), 3.83 - 3.78 (m, 1H, 5d-H), 3.74 - 3.59 (m, 2H, 6d-CH2), 2.72 - 2.51 (m, 2H, SEt-CH2), 1.27 (t, J = 7.4 Hz, 3H, SEt-CH3); 13 C NMR (151MHz, CDCl3) δ 138.4, 138.3, 137.8, 137.6, 128.5, 128.40, 128.38, 128.33,128.30, 128.01, 127.99, 127.9, 127.8, 127.7, 127.62, 127.60, 89.0 (1d-C),87.1, 83.0, 80.3, 76.2, 73.5, 73.4, 72.2, 71.9, 71.0, 25.3, 15.0; HR-ESI-MS(m / z): calcd for C 36 H 40 O5SNa + (M+Na) + : 607.2489, found: 607.2500. Compound 13*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-[2] -O -acetyl-4,6- O -Benzylacetal-3- O [-benzyl-β-D-galactopyranose-(1→6)]-2-N-acetyl-3- O -Acetopropionyl-2-deoxy-β-D-galactopyranose

[0056] Starting with β-D-galactospentaacetate purchased from Sinopharm Chemical Reagent Co., Ltd., and following a method reported in the literature (Zou Xiaopeng, Doctoral Dissertation, Jiangnan University, 2020), an end-group thioglycosylation reaction was carried out in the presence of ethanethiol and boron trifluoride diethyl ether to introduce an ethylthio group at the glycosyl end, followed by the removal of the acetyl group, to obtain an ethylthioglycoside intermediate. A portion of the ethylthioglycoside intermediate was then reacted with benzaldehyde dimethyl acetal under acid catalysis, following the method reported in the literature, to form benzyl groups at the O-4 and O-6 positions, thus obtaining a 4,6-O-benzyl-protected ethylthioglycoside intermediate. This intermediate was added to anhydrous methanol at a molar ratio of 1:1.2 with dibutyltin oxide and heated under reflux for 6 h under nitrogen protection. After the reaction was completed, the methanol was removed by concentration under reduced pressure. The residue was co-distilled three times with toluene to thoroughly remove residual methanol and water, yielding the corresponding organotin intermediate. The obtained organotin intermediate was dissolved in anhydrous N,N-dimethylformamide. Depending on the protecting group type of the target glycosyl donor, 1.3 molar equivalents of benzyl bromide were added, along with a catalytic amount of tetrabutylammonium iodide to promote the reaction. The reaction mixture was stirred at 50 °C for 12 h to complete the regioselective etherification reaction mediated by dibutyltin oxide. The thioglycoside intermediate was dissolved in anhydrous pyridine, and acetic anhydride and a catalytic amount of 4-dimethylaminopyridine were added, wherein the amount of acetic anhydride was 5.0 times the total molar amount of the remaining free hydroxyl groups in the substrate. The reaction system was stirred at room temperature for 8 h. The resulting 1.2 molar equivalents of the thioglycoside glycosyl donor and 1.0 molar equivalents of the disaccharide acceptor intermediate from the synthetic route of compound 5* were dissolved in anhydrous dichloromethane, and activated 4 Å molecular sieves were added. The mixture was stirred for 30 min under nitrogen protection. The reaction system was cooled to 0 °C, and 1.5 molar equivalents of N-iodosuccinimide and 0.1 molar equivalents of trimethylsilyltrifluoromethanesulfonate were added sequentially. The reaction was then brought to room temperature for 5 h to obtain a β-configuration trisaccharide intermediate. The obtained trisaccharide intermediate was dissolved in a dichloromethane / water mixture of 10:1, and 1.5 molar equivalents of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone were added. The reaction was carried out at 0 °C for 30 min, then brought to room temperature for another 4 h to selectively remove the 2-naphthylmethyl protecting group at the C3 position, yielding the target trisaccharide compound 13*. [α] 25 D = +25.19° ( c = 0.1, CHCl3); IR νmax (film) 3346,2924, 2855, 1738, 1697, 1551, 1497, 1454, 1422, 1368, 1235, 1163, 1104, 1056,1027, 1003, 915, 822, 764, 757, 748, 699, 598 cm -1; 1 H NMR (600 MHz, CDCl3) δ7.57 - 7.10 (m, 25H, Ar-H), 5.99 (d, J = 9.2 Hz, 1H, 2a-NH), 5.49 (s, 1H, Ar-CH), 5.39 (s, 1H, Ar-CH), 5.29 (dd, J = 10.0, 8.0 Hz, 1H, 2c-H), 5.21 - 5.13(m, 2H, Linker-CH2), 5.08 (dd, J = 10.0, 7.9 Hz, 1H, 2b-H), 5.01 (dd, J = 11.2,3.2 Hz, 1H, 3a-H), 4.68 - 4.66 (m, 1H, 1b-H), 4.65 (s, 1H, Ar-CH2), 4.59 (d, J = 12.6 Hz, 1H, Ar-CH2), 4.51 (d, J = 10.9 Hz, 2H, Linker-CH2), 4.43 (d, J = 7.5Hz, 1H, 1a-H), 4.38 (t, J = 6.7 Hz, 1H, 1c-H), 4.23 (d, J = 12.2 Hz, 1H, 6c-CH2), 4.20 - 4.10 (m, 3H, 4c-H, 6a-CH2), 4.01 (d, J = 3.6 Hz, 1H, 4a-H), 3.99(d, J = 1.7 Hz, 1H, 6c-CH2), 3.97 (dd, J = 4.8, 2.3 Hz, 2H, 2a-H, 4b-H), 3.84(ddd, J = 17.7, 10.7, 5.4 Hz, 3H, 3a-H, 6a-CH2), 3.75 (d, J = 12.4 Hz, 1H, 5b-H), 3.55 (s, 1H, 5a-H), 3.45 (dd, J= 10.3, 3.4 Hz, 1H, 3c-H), 3.42 - 3.25 (m,2H, Linker-CH2), 3.22 - 3.13 (m, 1H, 3b-OH), 2.97 (d, J = 7.1 Hz, 1H, 5c-H),2.88 (td, J = 12.3, 11.2, 5.1 Hz, 1H, Lev-CH2), 2.76 - 2.69 (m, 1H, Lev-CH2),2.64 (dd, J = 18.9, 5.4 Hz, 1H, Lev-CH2), 2.45 (ddd, J = 17.2, 6.3, 3.7 Hz, 1H,Lev-CH2), 2.24 (d, J = 7.4 Hz, 3H, Lev-CH3), 2.17 (s, 3H, Ac-CH3), 1.99 (d, J =5.2 Hz, 3H, Ac-CH3), 1.88 (d, J = 29.0 Hz, 3H, NHAc-CH3), 1.59 - 1.41 (m, 4H,Linker-CH2), 1.30 (s, 2H, Linker-CH2); 13 C NMR (151 MHz, CDCl3) δ 206.7, 172.4,169.4, 138.11, 138.06, 137.9, 137.8, 129.2, 128.8, 128.6, 128.4, 128.2,128.1, 128.0, 127.7, 127.6, 127.3, 126.6, 126.5, 101.7 (1c-C), 101.2, 101.1,100.6 (1a-C, 1b-C), 77.4, 75.6, 73.4, 73.2, 72.7, 71.5, 71.1, 70.4, 70.2,69.0, 68.8, 68.5, 67.2, 66.4, 66.0, 51.1, 50.4, 37.6, 29.8, 29.7, 27.7, 23.4,23.2, 21.1, 21.0; MALDI-TOF (m / z): calcd for C 70 H 82 N2O 22 Na + (M+Na)+ : 1325.5252,found: 1325.5269. Compound 18*: 2,3,4,6-tetra- O -benzyl-α-D-galactopyranose-(1→2)-5- O -Triethylamine phosphonate-1,3,4-tri- O -Benzyl-D-ribitol

[0057] Preparation of ribosome acceptors: Commercially available D-ribose was used as the starting material and dissolved in an allyl alcohol / acetone mixed solvent. A certain amount of concentrated sulfuric acid was added, and the mixture was stirred under reflux for 4 h to form allyl glycosides at the terminal hydroxyl groups, and the hydroxyl groups at the O2 and O3 positions were protected with propionide groups. The resulting intermediate was dissolved in anhydrous N,N-dimethylformamide, and 3.0 molar equivalents of sodium hydride were added at 0 °C. After stirring for 30 min, 2.0 molar equivalents of 2-bromomethylnaphthalene were added, and the mixture was heated to room temperature for 3 h to introduce 2-naphthylmethyl protecting groups onto the corresponding hydroxyl groups. Subsequently, the mixture was reacted with 80% aqueous acetic acid at 70 °C for 15 h to remove the propionide protecting groups at the O2 and O3 positions, yielding a diol intermediate. The above diol intermediate was added to anhydrous methanol with 1.2 molar equivalents of dibutyltin oxide, and the mixture was refluxed under nitrogen protection for 6 h. After concentration, the mixture was co-distilled three times with toluene. The obtained organotin intermediate was dissolved in anhydrous N,N-dimethylformamide, and 1.3 molar equivalents of benzyl bromide and a catalytic amount of tetrabutylammonium iodide were added. The mixture was reacted at 50 °C for 12 h to selectively benzylate the C3 hydroxyl group to obtain the corresponding ribosyl acceptor.

[0058] Preparation of galactose donor: β-D-galactospentaacetate (purchased from Sinopharm Chemical Reagent Co., Ltd.) was used as the starting material. Following a method reported in the literature (Zou Xiaopeng, Doctoral Dissertation, Jiangnan University, 2020), terminal thioglycosylation was carried out in the presence of a boron trifluoride diethyl ether complex, followed by removal of the acetyl protecting group to obtain the thioglycoside intermediate. This intermediate was dissolved in anhydrous N,N-dimethylformamide, and 5.0 molar equivalents of sodium hydride were added in portions at 0 °C. After stirring for 30 min, 6.0 molar equivalents of benzyl bromide were added, and the reaction was brought to room temperature for 4 h. The mixture was then purified to obtain the fully benzyl-protected galactosioglycoside donor.

[0059] The above-mentioned 2.0 molar equivalents of galactosuloside donor and 1.0 molar equivalent of ribose glycosyl acceptor were dissolved in a mixed solution of anhydrous diethyl ether and dichloromethane. Activated 4 Å molecular sieves were added, and the mixture was stirred for 30 min under nitrogen protection. The reaction system was cooled to 0 °C, and N-iodosuccinimide and trimethylsilyltrifluoromethanesulfonate were added sequentially in 1.5 molar equivalents. The reaction was carried out at room temperature for 6 h, utilizing the solvent effect of diethyl ether to improve the α-selectivity of the glycosylation reaction, yielding a disaccharide intermediate with the α-configuration as the predominant form. The obtained disaccharide intermediate was dissolved in a mixed solvent of ethyl acetate and 90% aqueous acetic acid, and 3.0 molar equivalents of palladium chloride and 10.0 molar equivalents of sodium acetate were added. The reaction was carried out at room temperature for 12 h, removing the allyl group at the ribose end to obtain a hemiacetal intermediate. Subsequently, the intermediate was dissolved in ethanol, and 0.6 molar equivalents of sodium borohydride were added at 0 °C. The reaction was then brought to room temperature for 1 h to reduce and open the ribose residues to a ribitol structure. The resulting ribitol disaccharide intermediate was dissolved in anhydrous N,N-dimethylformamide, and 1.5 molar equivalents of sodium hydride and 1.5 molar equivalents of benzyl bromide were added at 0 °C for each free hydroxyl group. The reaction was then brought to room temperature for 3 h to benzylate the free hydroxyl groups. The resulting intermediate was then dissolved in a 10:1 dichloromethane / water mixture, and 1.5 molar equivalents of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone were added. The reaction was then carried out at 0 °C for 30 min, followed by a further 3 h reaction at room temperature to selectively remove the 2-naphthylmethyl protecting group at the C5 position. Finally, the disaccharide intermediate with exposed hydroxyl groups was dissolved in anhydrous dichloromethane, cooled to 0 °C under nitrogen protection, and 3.0 molar equivalents of phosphorus trichloride and 6.0 molar equivalents of triethylamine were added. The mixture was reacted at 0 °C for 2 h. After post-processing and purification, H-phosphonate disaccharide donor 18* was prepared. 1 H NMR (400 MHz, MeOD) δ 7.51 - 7.07 (m, 35H, Ar-H), 5.48 (d, J = 3.4 Hz, 1H, 1g-H), 4.91 (s,1H, Ar-CH2), 4.79 - 4.65 (m, 6H, Ar-CH2), 4.59 - 4.50 (m, 3H, Ar-CH2), 4.40(s, 3H, Ar-CH2, 4f-H), 4.28 (d, J = 11.8 Hz, 2H, 6g-CH2, Ar-CH2), 4.20 (d, J=11.8 Hz, 1H, Ar-CH2), 4.16 - 4.09 (m, 2H, 5g-H, 6g-CH2), 4.04 - 3.96 (m, 3H,2g-H, 3g-H, 4g-H), 3.83 - 3.75 (m, 2H, 1f-CH2, 2f-H), 3.70 - 3.64 (m, 1H, 1f-CH2), 3.53 (t, J = 8.4 Hz, 1H, 5f-CH2), 3.37 - 3.35 (m, 2H, 3f-H, 5f-CH2); 13 CNMR (101 MHz, MeOD) δ 138.7, 138.61, 138.56, 138.3, 138.2, 138.12, 138.07,128.1, 128.04, 128.01, 127.95, 127.92, 127.87, 127.8, 127.7, 127.5, 127.42,127.40, 127.33, 127.27, 127.2, 127.1, 96.3 (1g-C), 78.9, 76.2, 75.2, 74.9,74.7, 73.0, 72.9, 72.4, 72.1, 72.0, 71.4, 69.1, 68.2; MALDI-TOF (m / z): calcdfor C 60 H 64 O 12 P - (M-Et3N-H) - :1007.4135, found: 1007.4137. Compound 25*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-[2] -O -acetyl-4,6- O -Benzylacetal-3- O [-benzyl-β-D-galactopyranose-(1→6)]-[2,3,5,6-tetra- O [-benzyl-β-D-galactofuranose-(1→3)]-2-N-acetyl-2-deoxy-β-D-galactopyranose

[0060] Starting with the levulinyl (Lev)-protected trisaccharide intermediate obtained during the preparation of compound 13*, it was dissolved in a mixed solvent of dichloromethane / methanol at a volume ratio of 20:1. 5.0 molar equivalents of hydrazine acetate were added, and the reaction was carried out at room temperature for 3 h to selectively remove the Lev protecting group, yielding the corresponding trisaccharide acceptor intermediate. 1.0 molar equivalents of the obtained trisaccharide acceptor and 3.0 molar equivalents of furanostosuloglycoside donor 9* were dissolved in anhydrous acetonitrile, and activated 4 Å molecular sieves were added. The mixture was stirred for 30 min under nitrogen protection. The reaction system was then cooled to 0 °C, and 1.5 molar equivalents of N-iodosuccinimide and 0.1 molar equivalents of trimethylsilyltrifluoromethanesulfonate were added sequentially. The reaction was carried out at 0 °C for 7 h to obtain a tetrasaccharide intermediate with a predominantly β-configuration. Finally, the obtained tetrasaccharide intermediate was dissolved in a dichloromethane / water mixed solvent, and 2.0 molar equivalents of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) were added. The mixture was reacted at room temperature for 3 h to selectively oxidize and remove the 2-naphthyl protecting group, exposing the corresponding hydroxyl group, and the target tetrasaccharide compound 25* was prepared. 1 H NMR (400 MHz, CDCl3) δ7.64 – 7.02 (m, 45H, Ar-H), 6.16 – 6.03 (m, 1H, 2a-NH), 5.40 (s, 1H, Ar-CH), 5.35 – 5.28 (m, 1H, 2b-H), 5.25 (s, 2H, Ar-CH, 1d-H), 5.20 – 5.05 (m, 2H, Linker-CH2), 4.89 (dd, J = 9.9, 7.9 Hz, 1H, 2b-H), 4.77 – 4.66 (m, 2H, 1b-H,Ar-CH2), 4.65 – 4.58 (m, 3H, 1a-H, Ar-CH2), 4.54 – 4.45 (m, 5H, Ar-CH2,Linker-CH2), 4.38 (dd, J = 11.3, 5.1 Hz, 3H, 1c-H, Ar-CH2), 4.24 (d, J = 11.0Hz, 3H, Ar-CH2, 4d-H, 5d-H), 4.14 – 4.06 (m, 2H, 6b-CH2, 6d-CH2), 4.02 (d, J=3.4 Hz, 2H, 3a-H, 4b-H), 3.97 – 3.88 (m, 3H, 4a-H, 4c-H), 3.85 – 3.76 (m, 3H,5a-H, 6b-CH2, 6d-CH2), 3.72 (td, J = 11.8, 10.5, 4.1 Hz, 3H, 6a-CH2, 5c-H),3.67 – 3.56 (m, 2H, 5b-H, 3c-H), 3.51 (d, J = 3.7 Hz, 1H, 3d-H), 3.48 – 3.25(m, 4H, 3b-H, 6c-CH2, 2d-H), 3.18 (t, J = 7.4 Hz, 1H, 2a-H), 3.03 (s, 1H,Linker-CH2), 2.77 (d, J = 9.9 Hz, 1H, Linker-CH2), 2.10 (d, J = 8.0 Hz, 3H, Ac-CH3), 1.99 (s, 3H, Ac-CH3), 1.84 (d, J = 33.3 Hz, 3H, NHAc-CH3), 1.62 – 1.44(m, 4H, Linker-CH2), 1.30 (s, 2H, Linker-CH2); 13C NMR (101 MHz, CDCl3) δ 169.4,138.4, 138.2, 138.1, 138.0, 137.8, 137.5, 137.3, 129.0, 128.8, 128.7, 128.6,128.48, 128.45, 128.5, 128.4, 128.3, 128.2, 128.11, 128.07, 128.01, 128.97,127.8, 127.7, 127.6, 127.4, 108.2 (1d-C), 101.8 (1c-C), 101.1, 100.9, 100.3(1a-C, 1b-C),88.8, 84.3, 82.4, 81.6, 75.3, 73.9, 73.7, 73.6, 73.4, 72.9,72.4, 71.8, 71.1, 70.9, 70.4, 70.2, 69.0, 68.6, 67.2, 66.4, 65.4, 50.4, 29.7,23.7, 21.2, 21.1; MALDI-TOF (m / z): calcd for C 99 H 110 N2O 25 Na + (M+Na) + : 1750.7324, found: 1750.7351. Compound 22*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl 2,3,6-tri- O -benzyl-5- O -(2-Naphthylmethyl)-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-[2] -O -acetyl-4,6- O -Benzylacetal-3- O [-benzyl-β-D-galactopyranose-(1→6)]-[2,3,5,6-tetra- O [-benzyl-β-D-galactofuranose-(1→3)]-2-N-acetyl-2-deoxy-β-D-galactopyranose

[0061] Using compound 25* as a glycosyl acceptor, it was dissolved in anhydrous acetonitrile in a molar ratio of 1.0:1.5 with furanyl galactose N-phenyltrifluoroacetylimide donor 3*. Activated 4 Å molecular sieves were added, and the mixture was stirred for 30 min under nitrogen protection. The reaction system was then cooled to 0 °C, and 0.1 molar equivalents of trimethylsilyltrifluoromethanesulfonate were added. The reaction was carried out at 0 °C for 5 h. Glycosylation occurred under the influence of donor activation and acetonitrile solvent effect, yielding a pentasaccharide intermediate predominantly in the β-configuration. Subsequently, the obtained pentasaccharide intermediate was dissolved in a dichloromethane / water mixed solvent, and 2.0 molar equivalents of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) were added. The reaction was carried out at room temperature for 3 h, selectively oxidizing and removing the 2-naphthylmethyl protecting group to expose the corresponding hydroxyl group, thus preparing the target pentasaccharide compound 22*. [α] 25 D = -109.95° ( c = 0.5, CHCl3); IR νmax(film) 2922, 2852, 1743, 1694, 1497, 1454, 1367, 1235, 1028, 820, 736, 698cm -1 ; 1 H NMR (600 MHz, CDCl3) δ 7.83 - 6.88 (m, 67H, Ar-H), 6.03 (s, 1H, 2a-NH), 5.39 (s, 1H, Ar-CH), 5.28 (t, J = 9.0 Hz, 1H, 2b-H), 5.24 - 5.09 (m, 6H,H-1d, 1e-H, 2c-H, Ar-CH, Linker-CH2), 4.83 (d, J = 11.9 Hz, 1H, Ar-CH2), 4.75(d, J = 7.5 Hz, 1H, 1b-H), 4.68 (d, J = 11.6 Hz, 1H, Ar-CH2), 4.63 (d, J = 12.6Hz, 1H, Ar-CH2), 4.58 - 4.42 (m, 10H, 1a-H, Linker-CH2, Ar-CH2), 4.40 - 4.24(m, 8H, 1c-H, Ar-CH2), 4.20 (s, 1H, 3c-H), 4.14 - 4.02 (m, 5H, 4b-H, 2d-H,3d-H, Ar-CH2), 3.97 (dd, J= 8.6, 3.9 Hz, 3H, 3a-H, 3b-H, 2e-H), 3.95 - 3.89(m, 3H, 5a-H, 4c-H, 5c-H), 3.86 (d, J = 10.7 Hz, 1H, 6b-CH2), 3.79 - 3.68 (m,5H, 2a-H, 4a-H, 6b-CH2, 3e-H, 6c-CH2), 3.65 (s, 1H, 6a-CH2), 3.63 - 3.52 (m,5H, 6a-CH2, 6d-CH2, 5b-H, 4d-H), 3.38 (s, 3H, 5d-H, 6e-CH2), 3.24 - 3.09 (m,3H, 6e-CH2, Linker-CH2), 2.87 (d, J = 12.6 Hz, 1H, 5e-H), 2.74 (d, J = 22.9 Hz,1H, 4e-H), 2.04 (d, J = 18.0 Hz, 3H, Ac-CH3), 1.98 (s, 3H, Ac-CH3), 1.87 - 1.74(m, 3H, NHAc-CH3), 1.48 (s, 4H, Linker-CH2), 1.30 (s, 2H, Linker-CH2); 13C NMR(151 MHz, CDCl3) δ 138.5, 138.2, 138.14, 138.08, 137.8, 137.7, 137.5, 137.4,135.8, 134.5, 133.2, 133.0, 130.9, 129.8, 129.0, 128.9, 128.6, 128.5, 128.42,128.36, 128.2, 128.1, 128.0, 127.94, 127.89, 127.8,127.71, 127.68, 127.65,127.56, 127.53, 127.46, 127.3, 127.0, 126.6, 126.42, 126.38, 126.1, 125.9,108.3 (1d-C, 1e-C), 101.2 (1c-C), 100.2 (1a-C, 1b-C), 96.1, 88.8, 88.4, 83.7,82.3, 81.6, 80.3, 76.0, 75.5, 73.4, 73.3, 72.3, 71.8, 71.7, 71.3, 71.2, 70.4,67.3, 65.6, 50.4, 31.9, 30.6, 30.2, 29.7, 29.4, 29.0, 22.7, 19.2, 14.1, 13.8;MALDI-TOF (m / z): calcd for C 137 H 146 N2O 30 Na + (M+Na) + : 2322.9887, found: 2322.9894. Compound 26*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl 2,3,4,6-tetra- O -Benzyl-α-D-galactopyranose-(1→2)-1,3,4-tri- O -Benzyl-D-ribitol phosphonate triethylamine salt H-phosphonate compound 18* (24.0 mg, 0.022 mmol) and N-benzyl-N-benzyloxycarbonyl-5-aminopentyl-1-ol (14.2 mg, 0.043 mmol) were dissolved in pyridine (0.2 mL). Trimethylacetyl chloride (PivCl, 8.0 µL, 0.068 mmol) was then slowly added. After stirring the reaction mixture at room temperature for 10 h, iodine (5.1 mg, 0.022 mmol) in a pyridine-water solution (96:4, v / v, 0.5 mL) was added in portions, and stirring was continued at room temperature for 2 h. The reaction mixture was diluted with dichloromethane (10 mL) and extracted with 10% sodium thiosulfate solution (10 mL) and 1.0 M triethylamine bicarbonate solution (TEAB) (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and then concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 6% methanol, v / v) to give a colorless oily compound 26* (24.5 mg, 0.018 mmol, 85%). f = 0.60 (petroleum ether / ethyl acetate 1:3 + 10% methanol, v / v). [α] 25 D = +9.52°( c = 0.5, CHCl3); IR νmax (film) 2955, 2924, 2854, 1703, 1604, 1513, 1496,1454, 1378, 1257, 1165, 1100, 1028, 829, 748, 697 cm -1 ; 1 H NMR (600 MHz, MeOD)δ 7.50 - 6.92 (m, 45H, Ar-H), 5.45 (d, J = 3.3 Hz, 1H, 1g-H), 5.13 (d, J = 16.9Hz, 2H, Linker-CH2), 4.85 (s, 1H, Ar-CH2), 4.78 - 4.66 (m, 5H, Ar-CH2), 4.61(d, J = 11.7 Hz, 1H, Ar-CH2), 4.58 - 4.49 (m, 3H, Ar-CH2), 4.40 (dd, J = 17.2,9.0 Hz, 3H, Linker-CH2, 1f-H), 4.36 (s, 2H, Ar-CH2), 4.31 (d, J= 6.5 Hz, 1H,6g-CH2), 4.23 (d, J = 11.8 Hz, 1H, Ar-CH2), 4.14 (dd, J = 16.4, 9.3 Hz, 2H, 5g-H, Ar-CH2), 4.08 (s, 1H, 6g-CH2), 4.02 - 3.93 (m, 3H, 2g-H, 3g-H, 4g-H), 3.85- 3.73 (m, 5H, 2f-H, 3f-H, 5f-CH2, Ar-CH2), 3.66 (dd, J = 10.5, 3.4 Hz, 1H, Ar-CH2), 3.49 (t, J = 8.5 Hz, 1H, Linker-CH2), 3.30 (dd, J = 9.0, 5.7 Hz, 1H,Linker-CH2), 3.18 - 3.12 (m, 1H, Linker-CH2), 3.08 (t, J = 7.5 Hz, 1H, Linker-CH2), 1.50 - 1.35 (m, 4H, Linker-CH2), 1.25 - 1.07 (m, 2H, Linker-CH2); 13 C NMR(151 MHz, MeOD) δ 138.7, 138.64, 138.60, 138.43, 138.40, 138.2, 138.1, 128.3,128.02, 128.0, 127.93, 127.90, 127.85, 127.7, 127.62, 127.56, 127.5, 127.39,127.37, 127.3, 127.2, 127.1, 127.0, 96.4 (1g-C), 79.1, 77.9, 77.6, 76.2,75.4, 75.0, 74.7, 73.0, 72.9, 72.4, 72.2, 72.0, 71.5, 69.1, 68.2, 67.0, 65.2,22.7, 7.9; MALDI-TOF (m / z): calcd for C 80 H 87 NO 15 P - (M-Et3N-H) - :1332.5818, found:1332.5823. Compound 27*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl 2,3,4,6-tetra-O-benzyl-α-D-galactopyranose-(1→2)-1,3,4-tri-O-benzyl-D-ribitol phosphonate-(5→5)-2,3,6-tri-O-benzyl-β-D-galactopyranose triethylamine salt H-phosphonate compound 18* (39.5 mg, 0.036 mmol) and compound N-benzyl-N-benzyloxycarbonyl-5-aminopentyl2,3,6-tri- O β-Benzyl-D-galactofuranose (18.0 mg, 0.024 mmol) was dissolved in pyridine (0.23 mL). Trimethylacetyl chloride (PivCl, 8.7 µL, 0.071 mmol) was then slowly added. The reaction mixture was stirred at room temperature for 12 h. Iodine (5.6 mg, 0.024 mmol) in a pyridine-water solution (96:4, v / v; 0.5 mL) was added in portions, and the reaction was stirred at room temperature for another 2 h. The reaction mixture was diluted with dichloromethane (10 mL) and extracted with 10% sodium thiosulfate solution (10 mL) and 1.0 M triethylamine bicarbonate solution (TEAB) (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and then concentrated under reduced pressure under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 6% methanol, v / v) to give a colorless oily compound 27* (33.5 mg, 0.019 mmol, 85%). f = 0.60 (petroleum ether / ethyl acetate 1:3 + 10% methanol, v / v). [α] 25 D = +25.20° ( c = 0.1, CHCl3); IR νmax (film)2954, 2923, 2853, 1702, 1496, 1454, 1377, 1210, 1096, 1027, 800, 743, 697,555, 460 cm -1 ; 1 H NMR (600 MHz, MeOD) δ 7.57 - 6.95 (m, 60H, Ar-H), 5.52 (s,1H, 1g-H), 5.18 (d, J = 20.1 Hz, 2H, Linker-CH2), 4.99 - 4.91 (m, 3H, 1e-H,Ar-CH2), 4.78 - 4.64 (m, 6H, Ar-CH2), 4.57 (d,J = 11.2 Hz, 3H, Ar-CH2), 4.49(d, J = 18.7 Hz, 4H, Ar-CH2, Linker-CH2), 4.42 (s, 3H, 2e-H, Ar-CH2), 4.35 (s,3H, Ar-CH2), 4.27 (d, J = 11.6 Hz, 2H, Ar-CH2), 4.21 - 4.11 (m, 3H, 3g-H, f-CH2), 4.07 (d, J = 9.9 Hz, 2H, 3e-H, 4e-H), 3.99 (d, J = 15.2 Hz, 3H, 2g-H, 4g-H, 3f-H), 3.81 (s, 3H, 5g-H, 6g-CH2, 4f-H), 3.64 (s, 1H, 6g-CH2), 3.56 (d, J =8.5 Hz, 1H, 6e-CH2), 3.45 (d, J = 7.2 Hz, 1H, 5e-H, 6e-CH2), 3.34 (s, 1H, 6e-CH2), 3.28 - 3.15 (m, 2H, Linker-CH2), 1.59 - 1.41 (m, 4H, Linker-CH2), 1.36(s, 2H, Linker-CH2); 13C NMR (151 MHz, MeOD) δ 138.7, 138.58, 138.55, 138.3,138.2, 138.1, 138.0, 137.9, 137.4, 128.4, 128.3, 128.2, 128.09, 128.06,128.03, 128.98, 127.93, 127.86, 127.73, 127.65, 127.6, 127.41, 127.36, 127.1,105.8 (1e-C), 96.6 (1g-C),88.0, 83.4, 80.4, 79.3, 76.2, 75.6, 74.9, 74.7,73.1, 72.9, 72.3, 72.1, 71.7, 69.1, 68.1, 67.2, 67.1, 67.0, 46.2, 43.0, 40.2,28.9, 27.7, 27.2, 23.2, 13.3, 12.2; MALDI-TOF (m / z): calcd for C 107 H 115 NO 20 P - (M-Et3N-H) - : 1765.7789, found: 1765.7769. The following describes the synthesis of key intermediates from the Streptococcus pneumoniae 10A serotype capsular polysaccharide oligosaccharide fragment library: N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl 2- O -acetyl-4,6- O The synthesis reaction equation for β-D-galactopyranose (2*) is as follows: Figure 3 As shown; Compound 1* (75.4 mg, 0.1 mmol) was dissolved in a mixture of dichloromethane and water (5:1, v / v, 3.4 mL), and DDQ (34.5 mg, 0.15 mmol) was added. The mixture was stirred at room temperature for 3 h. After the reaction was complete as monitored by TLC, the reaction solution was extracted with 10% sodium thiosulfate solution and back-extracted with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:1 v / v) to give 2* (51.1 mg, 0.082 mmol, 83%). f = 0.40 (petroleum ether / ethyl acetate 1:1, v / v). [α] 25 D = +6.48° ( c= 0.5, CHCl3); IR νmax(film) 3454, 2925, 2858, 1741, 1695, 1497, 1454, 1422, 1367, 1234, 1173,1102, 1057, 1028, 1001, 915, 822, 768, 758, 751, 746, 733, 699, 651, 598 cm -1 ; 1 H NMR (400 MHz, CDCl3) δ 7.72 - 7.01 (m, 15H, Ar-H), 5.55 (s, 1H, Ar-CH),5.17 (d, J = 11.7 Hz, 2H, Linker-CH2), 5.07 (dd, J = 10.0, 8.0 Hz, 1H, 2b-H),4.49 (d, J = 6.0 Hz, 2H, Linker-CH2), 4.39 (d, J = 9.1 Hz, 1H, 1b-H), 4.36 -4.30 (m, 1H, Linker-CH2), 4.20 (dd, J = 3.9, 1.2 Hz, 1H, 4b-H), 4.07 (dd, J =12.5, 1.8 Hz, 1H, Linker-CH2), 3.86 (d, J = 7.1 Hz, 1H, 6b-CH2), 3.76 - 3.67(m, 1H, 3b-H), 3.46 (m, 2H, 5b-H, 6b-CH2), 3.22 (d, J = 23.7 Hz, 2H, Linker-CH2), 2.49 (d, J = 11.2 Hz, 1H, 3b-OH), 2.07 (d, J = 8.2 Hz, 3H, Ac-CH3), 1.55(d, J = 16.5 Hz, 4H, Linker-CH2), 1.36 - 1.26 (m, 2H, Linker-CH2); 13C NMR (101MHz, CDCl3) δ 170.5, 137.9, 137.3, 129.3, 128.6, 128.5, 128.3, 127.8, 127.3,126.5, 101.6, 100.7 (1b-C), 75.6, 72.2, 71.8, 69.0, 67.2, 66.5, 29.1, 23.1,21.0; HR-ESI-MS (m / z): calcd for C 35 H 41 NO9Na + (M+Na) + : 642.2674, found:642.2682. N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl2,3,6-tri- O -benzyl-5- O -(2-Naphthylmethyl)-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O The synthesis reaction equation for β-D-galactopyranose (4*) is as follows: Figure 3 As shown; At 0 °C, donor 3* (39.8 mg, 0.052 mmol), acceptor 2* (16.2 mg, 0.026 mmol), and freshly activated 4 Å molecular sieve were added to anhydrous acetonitrile (2.6 mL), and the mixture was stirred for 30 min under argon protection. TMSOTf (2.84 µL, 0.015 mmol) was then added dropwise. The reaction was stirred at 0 °C for 7 h. When thin-layer chromatography showed complete conversion of the starting material, the mixture was quenched with triethylamine. The reaction solution was diluted with dichloromethane, extracted with saturated sodium bicarbonate solution, back-extracted with dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 3:1, v / v) to give colorless syrup 4* (17.0 mg, 0.014 mmol, yield 67%, α / β = 1:15). f = 0.50 (petroleum ether / ethyl acetate 2:1, v / v). [α] 25 D = -6.13° ( c= 1.0, CHCl3); IR νmax (film) 3031, 2926, 2864, 1752, 1697, 1496, 1454, 1421, 1367, 1230, 1176,1090, 1057, 1027, 1003, 912, 856, 821, 748, 697, 599, 475 cm -1 ; 1 H NMR (600MHz, CDCl3) δ 7.92 - 7.63 (m, 4H, Ar-H), 7.54 - 6.91 (m, 33H, Ar-H), 5.32 (s,1H, Ar-CH), 5.27 (t, J = 9.5 Hz, 1H, 2b-H), 5.23 (s, 1H, 1e-H), 5.16 (d, J =15.4 Hz, 2H, Linker-CH2), 4.87 (d, J = 11.9 Hz, 1H, Ar-CH2), 4.66 (d, J = 11.7Hz, 1H, Ar-CH2), 4.54 - 4.38 (m, 6H, Ar-CH2, Linker-CH2), 4.34 (d, J = 11.1 Hz,2H, Ar-CH2, 1b-H), 4.25 (s, 1H, 4b-H), 4.16 (dd, J = 8.7, 3.6 Hz, 1H, 3e-H),4.13 - 4.12 (m, 1H, Ar-CH2), 4.10 (s, 2H, 2e-H, 6e-CH2), 3.97 (dd, J = 8.3, 4.0Hz, 1H, 4e-H), 3.80 (dd, J = 24.4, 10.1 Hz, 2H, 6b-CH2, 5e-H), 3.71 (d, J =10.4 Hz, 1H, 3b-H), 3.63 (d, J = 9.6 Hz, 2H, 6e-CH2, Linker-CH2), 3.44 - 3.32(m, 1H, 6b-CH2), 3.27 - 3.14 (m, 3H, 5b-H, Linker-CH2), 1.96 (d, J= 18.8 Hz, 3H, Ac-CH3), 1.55 - 1.43 (m, 4H, Linker-CH2), 1.27 (d, J = 14.7 Hz, 2H, Linker-CH2); 13 C NMR (151 MHz, CDCl3) δ 138.1, 137.9, 137.8, 137.7, 137.3, 135.8,133.2, 133.0, 128.7, 128.5, 128.4, 128.2, 128.1, 127.9, 127.8, 127.7, 127.6,127.5, 127.2, 127.1, 126.4, 126.3, 126.1, 126.0, 108.3 (1e-C), 101.0 (1b-C),100.7, 88.5, 82.7, 80.5, 77.7, 76.4, 75.9, 73.6, 73.4, 71.9, 71.0, 70.2,68.8, 67.1, 66.7, 29.1, 23.1, 20.9; MALDI-TOF (m / z): calcd for C 73 H 77 NO 14 Na + (M+Na) + : 1214.5237, found: 1214.5256. N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl 2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-2-N-acetyl-6- O -acetyl-3- O The reaction equation for acetylpropionyl-2-deoxy-β-D-galactopyranose (6*) is as follows: Figure 3 As shown; Compound 5* (127.0 mg, 0.12 mmol) was dissolved in a mixture of dichloromethane and water (10:1, v / v, 4.0 mL), followed by the addition of DDQ (78.4 mg, 0.36 mmol). After stirring at room temperature for 4 h, the reaction was monitored by TLC until complete. The mixture was extracted with 10% sodium thiosulfate solution, and the aqueous phase was back-extracted with dichloromethane, dried over anhydrous sodium sulfate, filtered, and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 5% methanol, v / v) to give compound 6* (85.4 mg, 0.089 mmol, 77%). f = 0.35 (petroleum ether / ethyl acetate 1:3 + 10% methanol, v / v). [α] 25 D = +12.06° ( c = 0.5, CHCl3); IR νmax (film) 2924, 2854, 1738,1559, 1456, 1368, 1235, 1164, 1064, 769, 759, 747, 740, 700, 497 cm -1 ; 1 H NMR (600 MHz, CDCl3) δ 7.55 - 7.13 (m, 15H, Ar-H), 5.85 (d, J = 8.5 Hz, 1H, 2a-NH), 5.52 (s, 1H, Ar-CH), 5.21 - 5.05 (m, 5H, 3a-H, 2b-H, Linker-CH2), 4.74(d, J = 7.9 Hz, 1H, 1b-H), 4.55 (d, J = 8.8 Hz, 4H, 1a-H, 6b-CH2, Linker-CH2),4.34 - 4.27 (m, 1H, 6b-CH2), 4.27 - 4.22 (m, 2H, 6a-CH2), 4.12 (d, J = 3.1 Hz,1H, 2a-H), 4.09 - 4.02 (m, 1H, 6a-CH2), 3.94 - 3.84 (m, 3H, 4a-H, 3b-H, 4b-H), 3.69 (t, J= 5.9 Hz, 1H, 5b-H), 3.62 (s, 1H, 5a-H), 3.47 - 3.33 (m, 1H, Linker-CH2), 3.32 - 3.13 (m, 2H, Linker-CH2), 3.00 - 2.84 (m, 1H, Lev-CH2), 2.79 (d, J = 17.5 Hz, 1H, Lev-CH2), 2.70 - 2.59 (m, 1H, Lev-CH2), 2.56 - 2.40(m, 1H, Lev-CH2), 2.22 (d, J = 26.3 Hz, 6H, Ac-CH3), 2.04 (s, 3H, Lev-CH3), 1.89 (d, J = 17.0 Hz, 3H, NHAc-CH3), 1.62 - 1.43 (m, 4H, Linker-CH2), 1.31 (s,2H, Limker-CH2); 13 C NMR (151 MHz, CDCl3) δ 206.7, 172.4, 170.8, 137.8, 137.6,129.4, 128.6, 128.4, 128.0, 127.8, 127.3, 126.6, 101.6, 101.0 (1b-C), 100.4(1a-C), 75.6, 72.9, 72.6, 72.1, 71.5, 68.9, 67.2, 66.2, 63.7, 51.3, 50.4,47.4, 37.5, 29.9, 27.6, 23.5, 21.1, 21.0; MALDI-TOF (m / z): calcd forC 50 H 62 N2O 17 Na + (M+Na) + : 985.3941, found: 985.3968. N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl2,3,6-tri- O -benzyl-5- O -(2-Naphthylmethyl)-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-2-N-acetyl-6- O -acetyl-3-O The synthesis reaction equation for α-acetylpropionyl-2-deoxy-β-D-galactopyranose (7*) is as follows: Figure 3 As shown; Donor 3* (107.0 mg, 0.14 mmol), acceptor 6* (45.0 mg, 0.047 mmol), and dried 4Å molecular sieve were added to anhydrous acetonitrile (4.7 mL), and the mixture was stirred at 0 °C for 30 min. Then, trimethylsilyltrifluoromethanesulfonate (TMSOTf) (7.6 µL, 0.014 mmol) was added dropwise. The mixture was stirred at 0 °C for 5 h. When thin-layer chromatography showed complete conversion of the starting material, the reaction was quenched with triethylamine. The reaction solution was dissolved in dichloromethane, extracted with saturated sodium bicarbonate solution, and the aqueous phase was back-extracted with dichloromethane. The solution was then dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:4, v / v) to give colorless syrup 7* (45.2 mg, 0.028 mmol, 63%, α / β = 1:15). f = 0.20 (petroleum ether / ethyl acetate 1:4, v / v). [α] 25 D = -3.80° ( c = 0.5, CHCl3);IR νmax (film) 3031, 2925, 1739, 1693, 1549, 1497, 1454, 1422, 1367, 1231,1158, 1060, 857, 822, 757, 747, 698, 602, 475cm -1 ; 1 H NMR (600 MHz, CDCl3) δ7.83 - 7.69 (m, 4H, Ar-H), 7.49 - 7.40 (m, 5H, Ar-H), 7.39 - 6.94 (m, 28H, Ar-H), 5.75 (d, J = 8.9 Hz, 1H, 2a-NH), 5.33 - 5.29 (m, 1H, 2b-H), 5.27 (s,1H, Ar-H), 5.24 (s, 1H, 1e-H), 5.21 - 5.09 (m, 3H, Linker-CH2, 3a-H), 4.86(d, J= 11.7 Hz, 1H, Ar-CH), 4.69 (s, 2H, Ar-CH2, 1b-H), 4.55 - 4.45 (m, 7H,1a-H, Ar-CH2, Linker-CH2, 6e-CH2), 4.41 (d, J = 11.7 Hz, 1H, Ar-CH2), 4.35 (d, J = 11.5 Hz, 1H, Ar-CH2), 4.28 - 4.25 (m, 1H, 6e-CH2), 4.23 (d, J = 3.6 Hz, 1H,4b-H), 4.14 (dd, J = 8.4, 3.4 Hz, 1H, 3e-H), 4.13 - 4.10 (m, 1H, 2e-H), 4.09(s, 1H, Ar-CH2), 4.06 (s, 1H, 4a-H), 4.04 (s, 1H, 6b-CH2), 3.98 (dd, J = 8.4,4.4 Hz, 1H, 4e-H), 3.92 (d, J = 10.2 Hz, 1H, 3b-H), 3.89 - 3.82 (m, 1H, 2a-H),3.81 - 3.77 (m, 1H, 5e-H), 3.70 - 3.59 (m, 4H, 6a-CH2, 5b-H, 6b-CH2), 3.40 (s,2H, 5a-H, 6b-CH2), 3.30 - 3.12 (m, 2H, Linker-CH2), 2.94 - 2.86 (m, 1H, Lev-CH2), 2.77 - 2.60 (m, 2H, Lev-CH2), 2.48 - 2.40 (m, 1H, Lev-CH2), 2.18 (d, J =18.6 Hz, 6H, Ac-CH3), 2.01 (d, J = 5.7 Hz, 3H, Lev-CH3), 1.88 (d, J = 16.7 Hz,3H, NHAc-CH3), 1.58 - 1.44 (m, 4H, Linker-CH2), 1.34 - 1.27 (m, 2H, Linker-CH2); 13C NMR (151 MHz, CDCl3) δ 206.5, 172.4, 170.9, 138.1, 138.0, 137.9,137.7, 137.4, 135.7, 133.2, 133.0, 128.8, 128.54, 128.46, 128.2, 128.10,128.08, 127.90, 127.88, 127.84, 127.75, 127.72, 127.68, 127.6, 127.5, 127.3,127.2, 126.49, 126.47, 108.3 (1e-C), 101.3 (1b-C), 100.8, 100.3 (1a-C), 88.4,82.4, 80.1, 76.0, 75.9, 73.6, 73.4, 72.7, 72.1, 71.81, 71.76, 71.1, 70.7,68.7, 67.2, 66.3, 63.8, 51.1, 50.3, 47.3, 46.0, 37.6, 29.8, 27.6, 23.5, 21.1,21.0; MALDI-TOF (m / z): calcd for C 88 H 98 N2O 22 Na + (M+Na) + : 1557.6504, found:1557.6532. N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl 2- O -acetyl-4,6- O -Benzylacetal-3- O -(2-Naphthylmethyl)-β-D-galactopyranose-(1→4)-2-N-acetyl-6- O The synthesis reaction equation for acetyl-2-deoxy-β-D-galactopyranose (8*) is as follows: Figure 3 As shown; Compound 5* (220.0 mg, 0.2 mmol) was dissolved in a mixture of dichloromethane and methanol (20:1, v / v, 3.15 mL), and hydrazine acetate (27.5 mg, 0.3 mmol) was added. The mixture was stirred at room temperature for 3 h. After the reaction was complete as monitored by TLC, the reaction mixture was diluted with dichloromethane, extracted with saturated sodium bicarbonate solution, and the aqueous phase was back-extracted with dichloromethane. The solution was then dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 4% methanol, v / v) to give 8* (184.4 mg, 0.183 mmol, 92%). f = 0.50 (petroleum ether / ethyl acetate 1:3 + 10% methanol, v / v). [α] 25 D = -8.17° ( c = 1.0, CHCl3); IR νmax (film) 3327, 2925,2854, 1736, 1697, 1553, 1497, 1454, 1424, 1369, 1242, 1163, 1056, 1029, 858,822, 764, 749, 736, 699, 638, 614, 517, 477 cm -1 ; 1 H NMR (600 MHz, CDCl3) δ7.86 - 7.71 (m, 4H, Ar-H), 7.56 - 7.42 (m, 5H, Ar-H), 7.41 - 7.15 (m, 13H, Ar-H), 6.05 (s, 1H, 2a-NH), 5.47 - 5.35 (m, 2H, Ar-CH, 2b-H), 5.21 - 5.13 (m,2H, Linker-CH2), 4.84 - 4.73 (m, 3H, 1b-H, Linker-CH2), 4.60 - 4.42 (m, 3H,Ar-CH2, 6a-CH2), 4.31 (dd, J = 12.0, 7.3 Hz, 1H, 6a-CH2), 4.26 - 4.18 (m, 2H,1a-H, 6b-CH2), 4.11 (d, J = 3.5 Hz, 1H, 3b-H), 3.99 - 3.94 (m, 2H, 6b-CH2), 3.86 (s, 1H, 5a-H), 3.72 (d, J= 28.5 Hz, 2H, 2a-H, 5b-H), 3.66 - 3.56 (m, 3H,3a-H, 4a-H, 4b-H), 3.42 - 3.13 (m, 4H, Linker-CH2), 2.17 (d, J = 6.3 Hz, 3H,Ac-CH3), 2.01 (d, J = 8.6 Hz, 6H, Ac-CH3, NHAc-CH3), 1.54 (s, 4H, Linker-CH2), 1.33 (s, 2H, Linker-CH2); 13 C NMR (151 MHz, CDCl3) δ 171.0, 169.8, 137.8,136.7, 135.6, 133.1, 133.0, 129.1, 128.6, 128.5, 128.24, 128.18, 128.0,127.9, 127.7, 127.4, 127.3, 126.6, 126.4, 126.2, 126.0, 125.7, 102.0 (1b-C),101.4, 100.2 (1a-C), 75.0, 73.3, 72.5, 71.5, 70.5, 69.0, 68.3, 67.2, 66.3,64.2, 54.9, 50.4, 47.3, 46.1, 29.7, 28.7, 27.9, 27.0, 23.2, 21.2, 21.0;MALDI-TOF (m / z): calcd for C 56 H 64 N2O 15 Na + (M+Na) + : 1027.4199, found: 1027.4112. N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl 2- O -acetyl-4,6- O -Benzylacetal-3- O -(2-Naphthylmethyl)-β-D-galactopyranose-(1→4)-[2,3,5,6-tetra- O [-benzyl-β-D-galactofuranose-(1→3)]-2-N-acetyl-6- O The synthesis reaction equation for acetyl-2-deoxy-β-D-galactopyranose (10*) is as follows: Figure 3 As shown; Under argon protection, donor 9* (181.8 mg, 0.311 mmol) and acceptor 8* (62.5 mg, 0.062 mmol) were added to anhydrous acetonitrile (MeCN) (6.2 mL), followed by freshly activated 4 Å molecular sieve and N-iodosuccinimide (NIS) (87.4 mg, 0.389 mmol). The reaction was stirred at 0 °C for 30 min, followed by the addition of trimethylsilyltrifluoromethanesulfonate (TMSOTf) (11.3 µL, 0.062 mmol). The mixture was stirred at 0 °C for 7 h until the starting material was no longer observable by thin-layer chromatography. The reaction was quenched with triethylamine and filtered through diatomaceous earth. The reaction mixture was washed with 10% sodium thiosulfate solution and saturated sodium bicarbonate solution (2 × 20 mL), back-extracted with dichloromethane (3 × 20 mL), and the combined organic solvents were dried over anhydrous sodium sulfate and concentrated under vacuum. The crude product was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:1 v / v) to give 10* (55.1 mg, 0.036 mmol, 58%, α / β = 1:15). f = 0.55 (petroleum ether / ethyl acetate 2:3, v / v). [α] 25 D = +2.88° ( c = 0.1, CHCl3); IR νmax (film) 2925, 1740, 1693, 1455,1367, 1275, 1234, 1100, 1058, 767, 749, 739, 698 cm -1 ; 1 H NMR (600 MHz, CDCl3)δ 7.83 - 7.63 (m, 4H, Ar-H), 7.52 - 7.05 (m, 42H, Ar-H), 6.13 (s, 0.5H, 2a-NH), 5.68 - 5.62 (m, 0.5H, 2a-NH), 5.30 - 5.24 (m, 2H, 2b-H, 1d-H), 5.21 (s,1H, Ar-CH), 5.19 - 5.11 (m, 2H, Linker-CH2), 4.80 - 4.75 (m, 1H, 1b-H), 4.70(d, J = 7.8 Hz, 1H, 1a-H), 4.68 - 4.63 (m, 3H, Ar-CH2), 4.55 (d, J= 11.5 Hz,2H, Ar-CH2), 4.53 - 4.43 (m, 4H, 6a-CH2, 3b-H, Linker-CH2), 4.35 (q, J = 10.1,8.9 Hz, 2H, Ar-CH2), 4.30 (dd, J = 11.7, 4.3 Hz, 3H, 3d-H, Ar-CH2), 4.27 - 4.20(m, 2H, 6a-CH2, Ar-CH2), 4.11 (d, J = 2.7 Hz, 1H, 4a-H), 4.04 (d, J = 4.9 Hz, 1H, 4b-H), 3.89 (dd, J = 7.6, 3.5 Hz, 1H, 4d-H), 3.84 - 3.77 (m, 2H, 6b-CH2), 3.70 - 3.64 (m, 2H, 3a-H, 5a-H), 3.61 (dd, J = 10.5, 4.5 Hz, 1H, 6d-CH2), 3.49(dd, J = 10.1, 3.6 Hz, 1H, 2a-H), 3.46 - 3.32 (m, 2H, 5b-H, 6d-CH2), 3.30 -3.12 (m, 2H, Linker-CH2), 2.72 (d, J = 17.6 Hz, 1H, 5d-H), 2.10 (d, J = 5.9 Hz,3H, Ac-CH3), 2.00 (s, 3H, Ac-CH3), 1.84 (d, J = 35.2 Hz, 3H, NHAc-CH3), 1.59 -1.41 (m, 4H, Linker-CH2), 1.36 - 1.26 (m, 2H, Linker-CH2); 13C NMR (151 MHz, CDCl3) δ 170.9, 169.8, 138.4, 138.1, 137.8, 137.6, 137.3, 136.1, 133.2, 132.9, 128.9, 128.5, 128.42, 128.40, 128.2, 128.13, 128.07, 128.0, 127.8,127.69, 127.66, 127.3, 126.6, 126.1, 125.8, 125.7, 125.3, 108.6 (1d-C), 101.1(1b-C), 99.6 (1a-C),89.0, 84.1, 81.3, 73.7, 73.1, 72.29, 72.25, 71.8, 71.1,70.9, 70.2, 68.8, 67.2, 65.6, 64.6, 29.7, 23.8, 21.3, 21.0; MALDI-TOF (m / z):calcd for C 90 H 98 N2O 20 Na + (M+Na) + : 1549.6606, found: 1549.6619. N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl 2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-[2,3,5,6-tetra- O [-benzyl-β-D-galactofuranose-(1→3)]-2-N-acetyl-6- O The synthesis reaction equation for acetyl-2-deoxy-β-D-galactopyranose (11*) is as follows: Figure 3 As shown; Compound 10* (25.0 mg, 0.018 mmol) was added to a mixture of dichloromethane and water (5:1, v / v, 0.6 mL), followed by the addition of DDQ (6.13 mg, 0.027 mmol). The mixture was stirred at room temperature for 3 h. After the reaction was complete as monitored by TLC, the mixture was extracted with 10% sodium thiosulfate solution, followed by back-extraction with dichloromethane. The organic layer was dried over anhydrous sodium sulfate, filtered, and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 2:1, v / v) to give 11* (16.8 mg, 0.012 mmol, 74%). f = 0.45 (petroleum ether / ethyl acetate 1:1, v / v). [α]25 D =+26.34° ( c = 0.1, CHCl3); IR νmax (film) 2925, 1740, 1695, 1455, 1368, 1275,1234, 1090, 1055, 1027, 823, 767, 757, 748, 698 cm -1 ; 1 1H NMR (400 MHz, CDCl3) δ7.49 - 7.02 (m, 35H, Ar-H), 6.13 (s, 0.5H, 2a-NH), 5.57 (s, 0.5H, 2a-NH), 5.26 (s, 2H, 1d-H, Ar-CH), 5.15 (dd, J = 18.3, 6.1 Hz, 2H, Linker-CH2, 4.93(dd, J = 9.9, 7.9 Hz, 1H, 2b-H), 4.78 (d, J = 8.5 Hz, 1H, 1b-H), 4.73 - 4.65(m, 2H, 1a-H, Ar-CH2), 4.59 (d, J = 11.5 Hz, 2H, Ar-CH2), 4.53 - 4.35 (m, 7H,3a-H, 6b-CH2, Ar-CH2, Linker-CH2), 4.31 (d, J = 6.3 Hz, 1H, 4a-H), 4.28 - 4.20(m, 2H, 6b-CH2, Ar-CH2), 4.12 (d, J = 2.6 Hz, 1H, 5b-H), 4.05 (s, 1H, 2d-H),3.90 (dd, J = 7.5, 3.3 Hz, 1H, 4b-H), 3.85 (d, J = 12.3 Hz, 1H, 6a-CH2), 3.76 -3.65 (m, 3H, 5a-H, 4d-H, 6d-CH2), 3.59 (td, J = 7.2, 2.8 Hz, 1H, 6d-CH2), 3.52(d, J = 3.8 Hz, 1H, 3d-H), 3.45 (d, J= 11.8 Hz, 3H, 2a-H, 6a-CH2, 5d-H), 3.30- 3.14 (m, 2H, Linker-CH2), 2.81 (d, J = 8.7 Hz, 1H, 3b-OH), 2.09 (s, 3H, Ac-CH3), 2.01 (s, 3H, Ac-CH3), 1.86 (d, J = 23.6 Hz, 3H, NHAc-CH3), 1.63 - 1.44(m, 4H, Linker-CH2), 1.31 (s, 2H, Linker-CH2); 13 C NMR (101 MHz, CDCl3) δ 170.9,138.5, 138.1, 137.8, 137.6, 137.3, 129.2, 128.6, 128.5, 128.4, 128.24,128.22, 128.15, 128.10, 128.03, 127.98, 127.9, 127.82, 127.75, 127.6, 127.3,126.5, 108.4 (1d-C), 101.3, 100.5 (1b-C), 99.8 (1a-C), 88.9, 84.2, 81.5,78.9, 75.3, MALDI-TOF (m / z): calcd for C 79 H 90 N2O 20 Na + (M+Na) + :1409.5980, found: 1409.5993. N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl2,3,6-tri- O -benzyl-5- O -(2-Naphthylmethyl)-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-[2,3,5,6-tetra- O [-benzyl-β-D-galactofuranose-(1→3)]-2-N-acetyl-6- OThe synthesis reaction equation for acetyl-2-deoxy-β-D-galactopyranose (12*) is as follows: Figure 3 As shown; Under argon protection, donor 3* (43.9 mg, 0.058 mmol), acceptor 11* (16.0 mg, 0.012 mmol), and freshly activated 4Å molecular sieve were mixed with anhydrous acetonitrile (1.2 mL) at 0 °C and stirred for 30 min. Then, TMSOTf (3.1 µL, 0.017 mmol) was added dropwise. The mixture was stirred at 0 °C for 5 h. When thin-layer chromatography showed complete conversion of the starting material, the mixture was quenched with triethylamine. The reaction solution was diluted with dichloromethane, extracted with saturated sodium bicarbonate solution, back-extracted from the aqueous phase with dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 2:1, v / v) to give colorless syrup 12* (13.8 mg, 0.007 mmol, 61%, α / β = 1:15). f = 0.55 (petroleum ether / ethyl acetate 1:1, v / v). [α] 25 D = +19.37° ( c =0.1, CHCl3); IR νmax (film) 2924, 2858, 1741, 1697, 1454, 1424,1368, 1242,1163, 1056, 1028, 1003, 915, 821, 766, 742, 699, 651, 598cm -1 ; 1 H NMR (600MHz, CDCl3) δ 7.86 - 6.96 (m, 57H, Ar-H), 6.51 (d, J = 9.3 Hz, 0.5H, 2a-NH),5.68 (dd, J = 9.4, 2.7 Hz, 0.5H, 2a-NH), 5.26 - 5.09 (m, 6H, 1d-H, 1f-H, 2b-H,Ar-CH, Linker-CH2), 4.99 (d, J = 11.1 Hz, 1H, Ar-CH2), 4.84 (d, J = 11.9 Hz, 1H,Ar-CH2), 4.76 (d, J = 17.3 Hz, 1H, 1b-H), 4.66 (dd, J= 24.8, 11.5 Hz, 4H, 1a-H, Ar-CH2), 4.59 - 4.42 (m, 11H, Ar-CH2, Linker-CH2, 6b-CH2), 4.39 (td, J =7.7, 4.7 Hz, 4H, Ar-CH2, 2d-H), 4.36 - 4.25 (m, 5H, 3b-H, Ar-CH2), 4.21 (dd, J = 12.1, 7.5 Hz, 1H, 6b-CH2), 4.14 - 4.05 (m, 4H, 3a-H, 4a-H, 4d-H, Ar-CH2),4.02 - 3.99 (m, 1H, 4b-H), 3.97 (d, J = 4.1 Hz, 1H, 2e-H), 3.94 (d, J = 3.6 Hz,1H, 3e-H), 3.92 - 3.88 (m, 1H, 3d-H), 3.88 - 3.82 (m, 2H, 5a-H, 6d-CH2), 3.80(d, J = 1.8 Hz, 1H, 5b-H), 3.79 - 3.70 (m, 4H, 6a-CH2, 3d-H, 5d-H), 3.69 -3.62 (m, 3H, 4e-H, 5e-H, 6e-CH2), 3.62 - 3.54 (m, 2H, 2a-H, 6e-CH2), 3.22 -3.15 (m, 2H, Linker-CH2), 2.01 (d, J = 15.1 Hz, 6H, Ac-CH3), 1.89 - 1.75 (m,3H, NHAc-CH3), 1.56 - 1.44 (m, 4H, Linker-CH2), 1.31 (d, J = 9.0 Hz, 2H,Linker-CH2). 13 C NMR (151 MHz, CDCl3) δ 170.9, 170.5, 169.6, 138.4, 138.1,138.0, 137.8, 137.7, 137.4, 137.3, 135.9, 133.9, 133.2, 133.0, 128.4, 128.2,127.91, 127.86, 127.7, 127.5 (d, J= 5.3 Hz), 127.3, 126.9, 126.5, 126.4 (d, J = 7.1 Hz), 126.0, 125.9, 108.3 (1d-C, 1e-C), 101.1 (1b-C),100.6, 99.7 (1a-C),89.0, 88.3, ​​84.2, 83.7, 82.5, 81.5, 81.4, 80.4, 76.0, 75.6, 73.8, 73.7, 73.6,73.4, 73.32, 73.26, 72.3, 72.2, 71.9, 71.7, 71.3, 71.1, 70.8, 70.1, 68.6,67.2, 65.7, 64.6, 50.3, 47.3, 29.7, 23.7, 23.4, 21.3, 21.0. MALDI-TOF (m / z):calcd for C 117 H 126 N2O 25 Na + (M+Na) + : 1982.8567, found: 1982.8584. N-Benzyl-N-Benzyloxycarbonyl-5-aminopentyl2,3,6-tri- O -benzyl-5- O -(2-Naphthylmethyl)-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-[2] -O -acetyl-4,6- O -Benzylacetal-3- O [-benzyl-β-D-galactopyranose-(1→6)]-2-N-acetyl-3- O The synthesis reaction equation for α-acetylpropionyl-2-deoxy-β-D-galactopyranose (14*) is as follows: Figure 3 As shown; Donor 3* (34.7 mg, 0.046 mmol) and acceptor 13* (19.8 mg, 0.015 mmol) were dissolved in anhydrous acetonitrile (1.5 mL) at 0 °C, and freshly activated 4 Å molecular sieves were added. The mixture was stirred for 30 min under these conditions, and TMSOTf (2.5 µL, 0.014 mmol) was added dropwise under argon protection. The mixture was stirred at 0 °C for 5 h. When thin-layer chromatography showed complete conversion of the starting material, the mixture was quenched with triethylamine. The reaction solution was diluted with dichloromethane, extracted with saturated sodium bicarbonate solution, back-extracted with dichloromethane, dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:2, v / v) to give colorless syrup 14* (18.0 mg, 0.0095 mmol, 63%, α / β = 1:15). f = 0.50 (petroleum ether / ethyl acetate 1:4, v / v). [α] 25 D = +18.92° ( c = 0.1, CHCl3); IR νmax(film) 2924, 2854, 1741, 1697, 1497, 1454, 1367, 1232, 1158, 1088, 1057,1027, 822, 768, 757, 750, 742, 698, 602cm -1 ; 1 H NMR (600 MHz, CDCl3) δ 7.80 -7.69 (m, 4H, Ar-H), 7.53 - 6.96 (m, 43H, Ar-H), 5.80 (d, J = 12.7 Hz, 1H, 2a-NH), 5.37 (s, 1H, Ar-CH), 5.31 - 5.21 (m, 4H, 2b-H, 2c-H, 1e-H, Ar-CH), 5.17(d, J = 19.8 Hz, 2H, Linker-CH2), 4.96 (dd, J = 11.1, 3.2 Hz, 1H, 3a-H), 4.85(d, J = 11.7 Hz, 1H, Ar-CH2), 4.64 (dd, J = 12.1, 6.4 Hz, 3H, 1b-H, Ar-CH2),4.57 (d, J= 12.5 Hz, 1H, Ar-CH2), 4.55 - 4.45 (m, 5H, Ar-CH2, Linker-CH2),4.42 (s, 1H, Ar-CH2), 4.37 (d, J = 3.8 Hz, 1H, 1a-H), 4.35 (d, J = 11.4 Hz, 1H,Ar-CH2), 4.28 (d, J = 8.6 Hz, 1H, 1c-H), 4.20 (d, J = 3.6 Hz, 1H, 4b-H), 4.11(s, 5H, 4c-H, 2e-H, Ar-CH2), 4.02 (dd, J = 12.2, 1.6 Hz, 2H, 3e-H, 4e-H), 3.97(dd, J = 8.4, 4.4 Hz, 2H, 2a-H, 4c-H), 3.93 (dd, J = 10.3, 3.4 Hz, 2H, 5a-H,5b-H), 3.88 (dd, J = 10.3, 3.4 Hz, 1H, 3b-H), 3.78 (dd, J = 6.7, 4.8, 3.2 Hz,2H, 6a-CH2, 5b-H), 3.71 - 3.59 (m, 4H, 6b-CH2, 6c-CH2), 3.56 (dd, J = 12.2, 1.7Hz, 1H, 6a-CH2), 3.39 (d, J = 10.5 Hz, 2H, 6a-CH2, 3c-H), 3.34 (s, 1H, 4a-H),3.16 (s, 2H, Linker-CH2), 2.90 - 2.83 (m, 1H, Lev-CH2), 2.78 (s, 1H, 5e-H),2.70 - 2.60 (m, 2H, Lev-CH2), 2.47 - 2.40 (m, 1H, Lev-CH3), 2.17 (d, J = 9.4Hz, 6H, Ac-CH3), 1.97 (d, J = 7.0 Hz, 3H, Lev-CH3), 1.87 (d, J= 28.6 Hz, 3H,NHAc-CH3), 1.48 (s, 4H, Linker-CH2), 1.35 - 1.27 (m, 2H, Linker-CH2); 13 C NMR(151 MHz, CDCl3) δ 206.5, 172.4, 169.5, 138.5, 138.1, 137.9, 137.8, 137.6,137.4, 135.7, 133.2, 133.0, 128.8, 128.6, 128.5, 128.3, 128.2, 128.04,127.95, 127.9, 127.8, 127.7, 127.6, 127.4, 127.3, 127.2, 126.5, 126.1, 126.0,108.2 (1e-C), 101.8 (1c-C), 101.1 (1b-C), 100.8, 100.4 (1a-C),88.4, 82.4,80.1, 75.9, 75.8, 73.6, 73.4, 72.7, 71.84, 71.77, 71.1, 70.8, 70.6, MALDI-TOF (m / z): calcd for C 108 H 118 N2O 27 Na + (M+Na) + :1898.7848, found: 1898.7876. Compound 15*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl 2,3,6-tri- O -benzyl-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose Compound 4* (25.8 mg, 0.023 mmol) was dissolved in a mixture of dichloromethane and water (5:1, v / v, 0.77 mL), followed by the addition of DDQ (7.8 mg, 0.034 mmol). The mixture was stirred at room temperature for 3 h. After the reaction was completed as monitored by TLC, the reaction solution was extracted with 10% sodium thiosulfate solution, and the aqueous phase was back-extracted with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:1 v / v) to give 15* (15.5 mg, 0.015 mmol, 85%). f = 0.20 (petroleum ether / ethyl acetate 1:1, v / v). [α] 25 D = -9.10°( c = 0.1, CHCl3); IR νmax (film) 3032, 2919, 2863, 1752, 1697, 1497, 1454,1422, 1367, 1231, 1178, 1091, 1055, 1028, 1003, 912, 822, 738, 698, 600, 461cm -1 ; 1 H NMR (400 MHz, CDCl3) δ 7.51 - 7.09 (m, 30H, Ar-H), 5.41 (s, 1H, Ar-H), 5.30 (dd, J = 10.1, 8.0 Hz, 1H, 2b-H), 5.21 (s, 1H, 1e-H), 5.16 (d, J = 9.2 Hz,2H, Linker-CH2), 4.54 - 4.35 (m, 9H, 1b-H, Ar-CH2, Linker-CH2), 4.30 (d, J =3.7 Hz, 1H, 4b-H), 4.24 (d, J = 12.3 Hz, 1H, Ar-CH2), 4.12 (dd, J = 7.3, 3.9Hz, 2H, 2e-H, 3e-H), 3.99 (dd, J = 7.5, 3.6 Hz, 1H, 4e-H), 3.92 - 3.81 (m, 3H,5b-H, 6b-CH2), 3.75 (dd, J= 10.1, 3.6 Hz, 1H, 3b-H), 3.45 (d, J = 5.9 Hz, 2H,6e-CH2), 3.34 (s, 1H, 5e-H), 3.28 - 3.14 (m, 2H, Linker-CH2), 2.42 (d, J = 5.6Hz, 1H, 5e-OH), 1.98 (d, J = 10.4 Hz, 3H, Ac-CH3), 1.58 - 1.44 (m, 4H, Linker-CH2), 1.27 (s, 2H, Linker-CH2); 13 C NMR (101 MHz, CDCl3) δ 169.2, 137.9, 137.80,137.76, 137.7, 137.1, 128.7, 128.6, 128.5, 128.5, 128.4, 128.1, 128.0, 127.9,127.9, 127.8, 127.72, 127.65, 108.3 (1e-C), 101.0 (1b-C), 100.8, 87.8, 83.1,80.9, 77.7, 75.9, 73.5, 72.1, 71.9, 71.5, 70.2, 69.8, 68.9, 67.2, 66.7, 29.1,23.1, 20.9; MALDI-TOF (m / z): calcd for C 62 H 69 NO 14 Na + (M+Na) + : 1074.4611, found:1074.4634. Compound 16*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl 2,3,6-tri- O -benzyl-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-2-N-acetyl-6- O -acetyl-3- O -Acetopropionyl-2-deoxy-β-D-galactopyranose Compound 7* (29.5 mg, 0.019 mmol) was dissolved in a mixture of dichloromethane and water (5:1, v / v, 1.0 mL), followed by the addition of DDQ (6.5 mg, 0.029 mmol). The mixture was stirred at room temperature for 3 h. After the reaction was completed as monitored by TLC, the reaction solution was extracted with 10% sodium thiosulfate solution, and the aqueous phase was back-extracted with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 2% methanol, v / v) to give 16* (18.8 mg, 0.013 mmol, 70%). f = 0.45 (petroleum ether / ethyl acetate 1:3 + 5% methanol, v / v). [α] 25 D = -15.44° ( c = 0.5, CHCl3); IR νmax (film) 3030, 2924, 1754, 1694,1610, 1497, 1454, 1422, 1367,1230, 1143, 855, 822, 747, 698, 600, 474cm -1 ; 1 HNMR (600 MHz, CDCl3) δ 7.48 - 7.10 (m, 30H, Ar-H), 5.77 (d, J = 8.6 Hz, 1H,2a-NH), 5.37 (s, 1H, Ar-CH), 5.34 - 5.29 (m, 1H, 2b-H), 5.22 - 5.21 (m, 1H,1e-H), 5.21 - 5.14 (m, 2H, Linker-CH2), 5.12 (dd, J = 11.1, 3.1 Hz, 1H, 3a-H),4.70 (d, J = 7.9 Hz, 1H, 1b-H), 4.53 - 4.46 (m, 8H, 1a-H, Linker-CH2, Ar-CH2,6a-CH2), 4.43 (d, J = 11.7 Hz, 1H, Ar-CH2), 4.39 (d, J = 11.7 Hz, 1H, Ar-CH2),4.33 - 4.26 (m, 2H, 6a-CH2, 4b-H), 4.17 (dd, J= 12.3, 1.5 Hz, 1H, 6b-CH2),4.12 (dd, J = 3.9, 1.4 Hz, 1H, 2e-H), 4.11 - 4.07 (m, 2H, 4a-H, 4e-H), 3.98(dd, J = 7.7, 3.9 Hz, 1H, 3e-H), 3.95 (dd, J = 10.4, 3.3 Hz, 1H, 3b-H), 3.91 -3.85 (m, 2H, 2a-H, 6b-CH2), 3.67 (t, J = 5.7 Hz, 1H, 5e-H), 3.48 (s, 1H, 5b-H), 3.46 (d, J = 5.9 Hz, 2H, 6e-CH2), 3.40 (d, J = 8.9 Hz, 1H, 5a-H), 3.29 -3.16 (m, 2H, Linker-CH2), 2.94 - 2.86 (m, 1H, 5e-OH), 2.79 - 2.63 (m, 2H,Lev-CH2), 2.48 - 2.41 (m, 2H, Lev-CH2), 2.19 (d, J = 11.2 Hz, 6H, Ac-CH3), 2.02(s, 3H, Lev-CH3), 1.89 (d, J = 16.7 Hz, 3H, NHAc-CH3), 1.58 - 1.45 (m, 4H,Linker-CH2), 1.31 (s, 2H, Linker-CH2); 13C NMR (151 MHz, CDCl3) δ 206.6, 172.4,170.9, 137.93, 137.87, 137.8, 137.7, 137.2, 128.8, 128.54, 128.51, 128.3,128.1, 128.0, 127.9, 127.81, 127.79, 127.7, 127.3, 126.5, 108.4 (1e-C), 101.3(1b-C), 101.0, 100.4 (1a-C), 87.9, 83.0, 80.6, 75.9, 73.5, 72.7, 72.1, MALDI-TOF (m / z): calcd for C 77 H 90 N2O 22 Na + (M+Na) + : 1417.5878, found: 1417.5885. Compound 17*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl-2,3,6-tri- O -benzyl-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-[2] -O -acetyl-4,6- O -Benzylacetal-3- O [-benzyl-β-D-galactopyranose-(1→6)]-2-N-acetyl-3- O -Acetopropionyl-2-deoxy-β-D-galactopyranose Compound 14* (14.6 mg, 0.0078 mmol) was dissolved in a mixture of dichloromethane and water (5:1, v / v, 0.26 mL), followed by the addition of DDQ (2.65 mg, 0.012 mmol). The mixture was stirred at room temperature for 3 h. After the reaction was completed as monitored by TLC, the reaction solution was extracted with 10% sodium thiosulfate solution, and the aqueous phase was back-extracted with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 2% methanol, v / v) to give 17* (10.0 mg, 0.0058 mmol, 74%). f = 0.45 (petroleum ether / ethyl acetate 1:3 + 5% methanol, v / v). [α] 25 D = +38.41° ( c = 0.1, CHCl3); IR νmax (film) 2924, 2854, 1740,1698, 1455, 1368, 1233, 1158, 1091, 1054, 1027, 912, 822, 766, 742, 698,600cm -1 ; 1 H NMR (600 MHz, CDCl3) δ 7.59 - 6.91 (m, 40H, Ar-H), 5.84 (d, J = 9.0Hz, 1H, 2a-NH), 5.38 (s, 1H, Ar-CH), 5.35 (s, 1H, Ar-CH), 5.32 - 5.28 (m, 1H, 2b-H), 5.28 - 5.24 (m, 1H, 2c-H), 5.21 (d, J = 1.3 Hz, 1H, 1e-H), 5.17 (d, J =20.4 Hz, 2H, Linker-CH2), 4.97 (dd, J = 11.1, 3.1 Hz, 1H, 3a-H), 4.65 (s, 1H,1b-H), 4.64 (d, J = 5.4 Hz, 1H, Ar-CH2), 4.58 (d, J = 12.5 Hz, 1H, Ar-CH2), 4.54- 4.45 (m, 6H, Ar-CH2, Linker-CH2), 4.43 (d, J= 11.6 Hz, 2H, Ar-CH2), 4.40 (s,1H, Ar-CH2), 4.38 (s, 1H, 1a-H), 4.31 - 4.27 (m, 1H, 1c-H), 4.25 (d, J = 3.6Hz, 1H, 4b-H), 4.15 (t, J = 12.2 Hz, 3H, 6a-CH2, 6b-CH2), 4.12 - 4.10 (m, 2H,5a-H, 2e-H), 3.98 (dd, J = 7.6, 3.9 Hz, 2H, 2a-H, 4e-H), 3.95 (t, J = 4.3 Hz,2H, 3a-H, 4c-H), 3.92 - 3.89 (m, 1H, 3e-H), 3.87 (d, J = 4.9 Hz, 1H, 5c-H),3.82 - 3.74 (m, 3H, 6b-CH2, 5e-H), 3.68 (dd, J = 30.1, 10.5 Hz, 3H, 5c-H, 6e-CH2), 3.40 (d, J = 10.7 Hz, 5H, 4a-H, 5b-H, 3c-H, 6c-CH2), 3.21 - 3.11 (m, 2H,Linker-CH2), 2.81 (s, 1H, 5e-OH), 2.73 - 2.61 (m, 2H, Lev-CH2), 2.47 - 2.36(m, 2H, Lev-CH2), 2.18 (s, 3H, Ac-CH3), 1.98 (d, J = 6.3 Hz, 3H, Lev-CH3), 1.88(d, J = 28.5 Hz, 3H, NHAc-CH3), 1.49 (s, 4H, Linker-CH2), 1.31 (t, J = 4.7 Hz,2H, Linker-CH2); 13C NMR (151 MHz, CDCl3) δ 206.5, 172.4, 169.6, 169.5, 138.5,138.1, 137.9, 137.8, 137.7, 137.2, 128.8, 128.64, 128.56, 128.5, 128.3,128.04, 127.97, 127.8 (d, J = 3.2 Hz), 127.72, 127.69, 127.64, 127.57, 127.3,126.5, 108.3 (1e-C), 101.8 (1c-C), 101.1, 100.8 (1b-C), 100.5 (1a-C),87.8,83.0, 80.6, 75.8, 73.4, 72.8, 72.0, 71.8, 71.5, 71.1, 70.8, 70.6, 70.4, 69.8,69.0, 68.7, 68.2, 67.2, 66.3, 66.1, 50.9, 50.3, 47.4, 46.1, 37.6, 29.9, 29.7,27.6, 23.4, 23.2, 21.1, 21.0; MALDI-TOF (m / z): calcd for C 97 H 110 N2O 27 Na + (M+Na) + :1758.7222, found: 1758.7235. Compound 28*: N-benzyl-N-benzyloxycarbonyl-5-aminopentyl 2,3,4,6-tetra- O -Benzyl-α-D-galactopyranose-(1→2)-1,3,4-tri- O -Benzyl-D-ribitolphosphonic acid-(5→5)-2,3,6-tri- O -benzyl-β-D-galactofuranose-(1→3)-2- O -acetyl-4,6- O -Benzyl acetal-β-D-galactopyranose-(1→4)-[2,3,5,6-tetra- O [-benzyl-β-D-galactofuranose-(1→3)]-2-N-acetyl-6- O -Acetyl-2-deoxy-β-D-galactopyranose triethylamine salt Compound 12* (8.3 mg, 0.0042 mmol) was dissolved in a mixture of dichloromethane and water (5:1, v / v, 0.14 mL), followed by the addition of DDQ (1.44 mg, 0.006 mmol). The mixture was stirred at room temperature for 3 h. After the reaction was completed as monitored by TLC, the reaction solution was extracted with 10% sodium thiosulfate solution, and the aqueous phase was back-extracted with dichloromethane. The organic phase was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 2:1 v / v). H-phosphonate compound 18* (7.7 mg, 0.0069 mmol) and the above compound (4.2 mg, 0.0023 mmol) were dissolved in pyridine (1.0 mL). Trimethylacetyl chloride (PivCl, 1.69 µL, 0.014 mmol) was then slowly added. The reaction mixture was stirred at room temperature for 12 h. Iodine (0.54 mg, 0.0023 mmol) in a pyridine-water solution (96:4, v / v; 0.5 mL) was added, and the reaction was stirred at room temperature for another 2 h. After the reaction was completed as monitored by TLC, the reaction mixture was diluted with dichloromethane (10 mL) and extracted with 10% sodium thiosulfate solution (10 mL) and 1.0 M triethylamine bicarbonate solution (TEAB) (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and then concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 6% methanol, v / v) to give a colorless oily compound 28* (4.9 mg, 0.0017 mmol, 75%). f = 0.40 (petroleum ether / ethyl acetate 1:3 + 10% methanol, v / v). [α] 25 D = -24.85° ( c = 0.1,CHCl3); IR νmax (film) 3031, 2924, 2968, 1735, 1497, 1455, 1369, 1234, 1096,1028, 822, 736, 697, 600 cm -1 ; 1 H NMR (600 MHz, MeOD) δ 7.42 - 6.99 (m, 85H,Ar-H), 5.45 (s, 1H, Ar-CH), 5.42 (d, J= 3.6 Hz, 1H, 1g-H), 5.27 (s, 1H, 2b-H), 5.21 (s, 2H, 1d-H, 1e-H), 5.18 - 5.12 (m, 2H, Linker-CH2), 4.81 (d, J =11.2 Hz, 2H, 1b-H, Ar-CH2), 4.68 - 4.61 (m, 5H, Ar-CH2), 4.58 (d, J = 12.7 Hz,3H, Ar-CH2), 4.54 (d, J = 11.7 Hz, 1H, Ar-CH2), 4.53 - 4.43 (m, 8H, Ar-CH2,Linker-CH2), 4.41 - 4.37 (m, 3H, Ar-CH2), 4.35 - 4.31 (m, 6H, 1a-H, 3b-H, 2d-H, Ar-CH2), 4.29 - 4.20 (m, 7H, Ar-CH2), 4.14 (d, J = 10.6 Hz, 4H, Ar-CH2),4.11 - 4.04 (m, 4H, 3e-H, 2g-H, Ar-CH2), 4.02 (d, J = 3.2 Hz, 1H, 2f-H), 4.01- 3.93 (m, 4H, 3a-H, 4a-H, 2e-H, 3g-H), 3.91 (dd, J = 7.6, 3.1 Hz, 2H, 4b-H,3d-H), 3.87 (d, J = 10.7 Hz, 3H, 2a-H, 6b-CH2, 3f-H), 3.77 - 3.67 (m, 9H, 5b-H, 5f-CH2, 5d-H, 4e-H, 6e-CH2, 4g-H, 5g-H), 3.65 (s, 1H, 6a-CH2), 3.62 - 3.55(m, 3H, 5a-H, 6a-CH2, 5e-H), 3.53 (d, J = 10.1 Hz, 2H, 6e-CH2), 3.46 - 3.42 (m,1H, 5f-CH2), 3.40 (s, 1H, 4d-H), 3.25 - 3.16 (m, 4H, 6d-CH2, Linker-CH2), 2.94- 2.88 (m, 1H, 4f-H), 2.13 (d,J = 20.0 Hz, 3H, Ac-CH3), 2.03 - 1.95 (m, 3H,Ac-CH3), 1.85 (d, J = 18.0 Hz, 3H, NHAc-CH3), 1.62 - 1.53 (m, 4H, Linker-CH2), 1.50 - 1.44 (m, 2H, Linker-CH2); 13 C NMR (151 MHz, MeOD) δ 171.2, 138.7, 138.5,138.3, 138.2, 138.1, 138.0, 137.2, 137.1, 131.0, 128.6, 128.4, 128.31,128.29, 128.2, 128.09, 128.06, 128.05, 128.02, 127.96, 127.94, 127.89, 127.8,127.7, 127.6, 127.41, 127.37, 127.35, 127.31, 127.28, 127.2, 127.1, 127.0,126.1, 108.8 (1d-C, 1e-C), 101.0 (1a-C, 1b-C), 96.4 (1g-C), 83.6, 76.2, 74.7,73.13, 73.05, 73.0, 72.8, 72.7, 72.2, 72.1, 72.0, 71.8, 71.5, 69.0, 68.3,68.1, 67.2, 64.4, 58.7, 58.5, 58.4, 53.4, 48.4, 35.3, 33.7, 31.7, 30.4, 29.4,29.3, MALDI-TOF (m / z): calcd for C 166 H 180 N2O 37 P - (M-Et3N-H) - : 2825.2041, found: 2825.2065. Example 2: Synthesis of Oligosaccharide Compounds The synthesis reaction equation for N-aminopentylβ-D-galactopyranose-(1→4)-[β-D-galactopyranose-(1→6)]-2-N-acetyl-2-deoxy-β-D-galactopyranose (3a) is as follows: Figure 4 As shown; Compound 13* (50.4 mg, 0.036 mmol) was dissolved in a mixture of methanol and tetrahydrofuran (2.5:1, v / v, 2 mL). Sodium methoxide (0.98 mg, 0.018 mmol) was added, and the mixture was stirred at room temperature for 30 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0062] It was then dissolved in a mixture of tert-butanol / water / dichloromethane (5:2:1, v / v; 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction was stirred under hydrogen (40 psi) for 24 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography and lyophilized to give compound 3a (17.1 mg, 0.027 mmol, 75%). 1 H NMR (600 MHz, D2O) δ 4.55 (d, J = 7.5 Hz, 1H, 1b-H), 4.51 - 4.41 (m,2H, 1a-H, 1c-H), 4.20 - 4.10 (m, 2H, 4b-H, 6b-CH2), 3.96 (m, J = 13.8, 11.4,8.3 Hz, 2H, 2a-H, 6b-CH2), 3.93 - 3.85 (m, 4H, 4a-H, 6a-CH2, 3b-H, 5c-H), 3.82- 3.69 (m, 5H, 3a-H, 6c-CH2, Linker-CH2), 3.69 - 3.55 (m, 6H, 5a-H, 6a-CH2,2b-H, 5b-H, 3c-H, 4c-H), 3.50 (dd, J = 9.9, 7.8 Hz, 1H, 2c-H), 2.97 (t, J = 7.7Hz, 2H, Linker-CH2), 2.02 (s, 3H, NHAc-CH3), 1.66 (t, J= 7.7 Hz, 2H, Linker-CH2), 1.61 - 1.55 (m, 2H, Linker-CH2), 1.42 - 1.35 (m, 2H, Linker-CH2); 13 C NMR(151 MHz, D2O) δ 174.8, 104.2 (1b-C), 103.5 (1c-C), 101.3 (1a-C), 77.7, 76.8,75.14, 75.05, 73.7, 72.7, 71.5, 71.4, 70.7, 70.1, 70.0, 68.6, 61.0, 60.9,52.9, 39.3, 29.8, 28.1, 26.4, 24.9, 22.2, 22.1; HR-ESI-MS (m / z): calcd forC 25 H 46 N2O 16 Na + (M+Na) + : 653.2740, found: 653.2756. The synthesis reaction equation for N-aminopentyl α-D-galactopyranose-(1→2)-D-ribitol phosphonate-(5→5)-β-D-furanose-(1→3)-β-D-galactopyranose sodium salt (4c) is as follows: Figure 4 As shown; H-phosphonate compound 18* (25.8 mg, 0.023 mmol) and compound 15* (12.2 mg, 0.012 mmol) were dissolved in pyridine (1.0 mL). Trimethylacetyl chloride (PivCl, 5.68 µL, 0.046 mmol) was then slowly added. The reaction mixture was stirred at room temperature for 12 h. Iodine (2.74 mg, 0.012 mmol) in a pyridine-water solution (96:4, v / v; 0.5 mL) was added in portions, and the reaction was stirred at room temperature for another 2 h. The reaction mixture was diluted with dichloromethane (10 mL) and extracted with 10% sodium thiosulfate solution (10 mL) and 1.0 M triethylamine bicarbonate solution (TEAB) (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and then concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 6% methanol, v / v) to give a colorless oily compound 19* (18.2 mg, 0.0009 mmol, 76%).

[0063] Compound 19* (8.6 mg, 0.0042 mmol) was dissolved in methanol (2 mL). Sodium methoxide (0.1 mg, 0.0021 mmol) was added, and the mixture was stirred at room temperature for 12 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0064] It was then dissolved in a mixture of ethyl acetate / methanol / water / acetic acid (v / v ratio 1:1:0.5:0.2, 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction mixture was stirred for 36 h under hydrogen (40 psi). The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography. The lyophilized compound was passed through a Dowex X-8 resin (sodium form) column and eluted with 10 mL of ultrapure water. Lyophilization gave compound 4c (2.52 mg, 0.0031 mmol, 75%). 1 H NMR (600 MHz, D2O) δ 5.07 (d, J = 4.0 Hz, 1H, 1g-H), 5.05(d, J = 2.1 Hz, 1H. 1e-H), 4.30 (d, J = 8.0 Hz, 1H, 1b-H), 4.21 - 4.15 (m, 1H,5b-H), 4.07 - 3.99 (m, 3H, 2f-H, 4b-H, 3e-H, 2f-H), 4.00 - 3.92 (m, 2H, 3g-H,Linker-CH2), 3.91 - 3.83 (m, 5H, 2e-H, 5e-H, 4g-H, 3f-H, 4f-H, Linker-CH2), 3.81 - 3.74 (m, 3H, 3b-H, 4e-H, 6g-CH2), 3.69 - 3.65 (m, 4H, 6e-CH2, 2g-H, 5f-CH2), 3.63 - 3.57 (m, 5H, 6b-CH2, 6e-CH2, f-CH2), 3.55 (dd, J = 10.3, 4.9, 2.7Hz, 3H, 6b-CH2, 5g-H, 6g-CH2), 3.46 (dd, J= 9.9, 7.9 Hz, 1H, 2b-H), 2.90 -2.77 (m, 2H, Linker-CH2), 1.59 - 1.45 (m, 4H, Linker-CH2), 1.35 - 1.27 (m, 2H, Linker-CH2); 13 C NMR (151 MHz, D2O) δ 108.9 (1e-C), 102.4 (1b-C), 98.9 (1g-C), 81.5, 81.34, 81.31, 80.7, 79.2, 76.0, 75.0, 74.6, 74.5, 71.5, 71.4, 70.5,70.4, 69.90, 69.87, 69.4, 69.2, 68.6, 68.5, 67.0, 66.9, 61.2, 61.0, 60.9,59.8, 39.3, 28.1, 26.4, 22.1; HR-ESI-MS (m / z): calcd for C 28 H 53 NO 23 P - (M+H) - :802.2751, found: 802.2747. The synthesis reaction equation for N-aminopentyl α-D-galactopyranose-(1→2)-D-ribitol phosphonate-(5→5)-β-D-furanose-(1→3)-β-D-galactopyranose-(1→4)-2-N-acetyl-2-deoxy-β-D-galactopyranose sodium salt (5b) is as follows: Figure 4 As shown; H-phosphonate compound 18* (28.0 mg, 0.025 mmol) and compound 16* (9.2 mg, 0.0066 mmol) were dissolved in pyridine (1.0 mL). Trimethylacetyl chloride (PivCl, 6.2 µL, 0.05 mmol) was then slowly added. After stirring the reaction mixture at room temperature for 12 h, iodine (1.5 mg, 0.0066 mmol) in a pyridine-water solution (96:4, v / v; 0.5 mL) was added in portions, and the reaction was stirred at room temperature for another 2 h. After the reaction was completed as monitored by TLC, the reaction mixture was diluted with dichloromethane (10 mL) and extracted with 10% sodium thiosulfate solution (10 mL) and 1.0 M triethylamine bicarbonate solution (TEAB) (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and then concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 6% methanol, v / v) to give a colorless oily compound 20* (10.9 mg, 0.0044 mmol, 66%).

[0065] Compound 20* (13.7 mg, 0.0055 mmol) was dissolved in methanol (2 mL). Sodium methoxide (0.15 mg, 0.0027 mmol) was added, and the mixture was stirred at room temperature for 12 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0066] It was then dissolved in a mixture of ethyl acetate / methanol / water / acetic acid (v / v ratio 1:1:0.5:0.2, 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction mixture was stirred for 36 h under hydrogen (40 psi). The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography. The lyophilized compound was passed through a Dowex X-8 resin (sodium form) column and eluted with 10 mL of ultrapure water. Lyophilization gave compound 5b (2.11 mg, 0.002 mmol, 77%). 1 H NMR (600 MHz, Chloroform- d ) δ 5.23 (dd, J = 6.2, 3.1 Hz,2H, 1e-H, 1g-H), 4.68 - 4.62 (m, 1H, 1b-H), 4.49 (d, J= 8.5 Hz, 1a-H), 4.37 -4.32 (m, 1H, 2f-H), 4.24 - 4.19 (m, 1H, 2e-H, 4e-H, 3g-H), 4.17 (dd, J = 7.1,4.2 Hz, 1H, 4b-H), 4.14 (dd, J = 11.1, 5.4, 2.6 Hz, 1H, Linker-CH2), 4.10 (d, J = 1.9 Hz, 1H, 4g-H), 4.05 (s, 1H, 3b-H), 4.02 (t, J = 2.3 Hz, 4H, 5a-H, 3f-H,5g-H, Linker-CH2), 3.98 - 3.96 (m, 1H, 2a-H), 3.95 - 3.91 (m, 3H, 5e-H, 6g-CH2), 3.90 - 3.81 (m, 8H, 3a-H, 6a-CH2, 3e-H, 6e-CH2, 2g-H), 3.80 - 3.76 (m,3H, 4a-H, 5f-CH2), 3.76 - 3.73 (m, 4H, 2b-H, 4f-H, f-CH2), 3.72 (q, J = 6.4,5.4 Hz, 2H, 5b-H, 6b-CH2), 3.61 (dt, J = 10.1, 6.3 Hz, 1H, 6b-CH2), 3.02 - 2.96(m, 2H, Linker-CH2), 2.05 (s, 3H, NHAc-CH3), 1.73 - 1.65 (m, 2H, Linker-CH2),1.64 - 1.56 (m, 2H, Linker-CH2), 1.46 - 1.38 (m, 2H, Linker-CH2); 13C NMR (151MHz, Deuterium Oxide) δ 174.8, 108.9 (1e-C), 104.2 (1b-C), 101.4 (1a-C), 98.9(1g-C), 81.4, 81.3, 80.5, 79.2, 76.7, 76.0, 75.0, 74.5, 74.1, 71.5, 71.3,70.5, 70.41, 70.36, 69.9, 69.3, 69.2, 68.5, 68.4, 66.9, 62.4, 61.1, 61.0,60.9, 60.5, 59.7, 53.0, 39.3, 28.0, 26.4, 22.1 (d, J = 3.5 Hz); HR-ESI-MS (m / z): calcd for C 36 H 66 N2O 28 P - (M+H) - : 1005.3545, found: 1005.3540. The synthesis reaction equation for N-aminopentyl α-D-galactopyranose-(1→2)-D-ribitol phosphonate-(5→5)-β-D-furanose-(1→3)-β-D-galactopyranose-(1→4)-[β-D-galactopyranose-(1→6)]-2-N-acetyl-2-deoxy-β-D-galactopyranose sodium salt (6a) is as follows: Figure 4 As shown; H-phosphonate compound 18* (25.6 mg, 0.023 mmol) and compound 17* (10.0 mg, 0.0057 mmol) were dissolved in pyridine (1.0 mL). Trimethylacetyl chloride (PivCl, 5.6 µL, 0.046 mmol) was then slowly added. After stirring the reaction mixture at room temperature for 12 h, iodine (1.4 mg, 0.0057 mmol) in a pyridine-water solution (96:4, v / v; 0.5 mL) was added in portions, and the reaction was stirred at room temperature for another 2 h. After the reaction was completed as monitored by TLC, the reaction mixture was diluted with dichloromethane (10 mL) and extracted with 10% sodium thiosulfate solution (10 mL) and 1.0 M triethylamine bicarbonate solution (TEAB) (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and then concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 6% methanol, v / v) to give a colorless oily compound 21* (12.9 mg, 0.0047 mmol, 82%).

[0067] Compound 21* (7.9 mg, 0.0029 mmol) was dissolved in methanol (2 mL). Sodium methoxide (0.08 mg, 0.0014 mmol) was added, and the mixture was stirred at room temperature for 12 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0068] It was then dissolved in a mixture of ethyl acetate / methanol / water / acetic acid (v / v ratio 1:1:0.5:0.2, 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction mixture was stirred at hydrogen (40 psi) for 36 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography. The lyophilized compound was passed through a Dowex X-8 resin (sodium form) column and eluted with 10 mL of ultrapure water. Lyophilization gave compound 6a (2.52 mg, 0.0022 mmol, 75%). 1 H NMR (600 MHz, D2O) δ 5.23 (dd, J = 8.2, 3.1 Hz, 2H, 1g-H,1e-H), 4.66 - 4.61 (m, 1H, 1b-H), 4.49 (dd, J = 15.3, 8.2 Hz, 2H, 1a-H, 1c-H), 4.38 - 4.32 (m, 1H, 3a-H), 4.24 - 4.20 (m, 3H, 4b-H, 3c-H, 3e-H), 4.17 (dt, J = 8.2, 2.3 Hz, 2H, 6a-CH2), 4.13 (d, J = 3.9 Hz, 1H, Linker-CH2), 4.10 (s, 1H,2e-H), 4.07 - 3.97 (m, 7H, 2b-H, 3b-H, 2c-H, 2f-H, 4f-H, Linker-CH2), 3.96 -3.90 (m, 5H, 2a-H, 6c-CH2, 4e-H, 2g-H), 3.89 - 3.81 (m, 6H, 5b-H, 6b-CH2, 4c-H, 3f-H, 4g-H), 3.80 - 3.72 (m, 9H, 4a-H, 5e-H, 6e-CH2, 5f-CH2, f-CH2), 3.70(dd, J= 7.7, 4.8 Hz, 2H, 5g-H, f-CH2), 3.67 - 3.60 (m, 2H, 5a-H, 3g-H), 3.53(t, J = 8.9 Hz, 1H, 5c-H), 3.00 (t, J = 7.6 Hz, 2H, Linker-CH2), 2.05 (s, 3H,NHAc-CH3), 1.73 - 1.66 (m, 2H, Linker-CH2), 1.64 - 1.58 (m, 2H, Linker-CH2),1.45 - 1.38 (m, 2H, Linker-CH2); 13 C NMR (151 MHz, D2O) δ 174.8, 108.9 (1e-C), 104.1 (1b-C), 103.5 (1c-C), 101.3 (1a-C), 98.9 (1g-C), 81.5, 80.5, 79.2, 77.1, 76.0, 75.1, 75.0, 73.6, 72.7, 71.5, 71.4, 70.7, 70.6, 70.4, 70.1, 69.4, 69.2,68.6, 68.5, 66.9, 61.2, 61.0, 60.9, 59.8, 53.0, 39.3, 28.1, 26.3, 22.1;MALDI-TOF (m / z): calcd for C 42 H 76 N2O 33 P - (M+H) - : 1167.4073, found: 1167.4068. The synthesis reaction equation for N-aminopentyl α-D-galactopyranose-(1→2)-D-ribitol phosphonate-(5→5)-β-D-galactopyranose-(1→3)-β-D-galactopyranose-(1→4)-[β-D-galactopyranose-(1→6)]-[β-D-galactopyranose-(1→3)]-2-N-acetyl-2-deoxy-β-D-galactopyranose sodium salt (7) is as follows: Figure 4 As shown; H-phosphonate compound 18* (23.7 mg, 0.021 mmol) and compound 22* (7.7 mg, 0.0036 mmol) were dissolved in pyridine (1.0 mL). Trimethylacetyl chloride (PivCl, 6.6 µL, 0.053 mmol) was then slowly added. After stirring the reaction mixture at room temperature for 12 h, iodine (0.54 mg, 0.0036 mmol) in a pyridine-water solution (96:4, v / v; 0.5 mL) was added in portions, and the reaction was stirred at room temperature for another 2 h. After the reaction was completed as monitored by TLC, the reaction mixture was diluted with dichloromethane (10 mL) and extracted with 10% sodium thiosulfate solution (10 mL) and 1.0 M triethylamine bicarbonate solution (TEAB) (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and then concentrated under vacuum. The residue was purified by silica gel column chromatography (petroleum ether / ethyl acetate 1:3 + 2% methanol, v / v) to give a colorless oily compound 23* (7.34 mg, 0.0023 mmol, 65%).

[0069] Compound 23* (8.7 mg, 0.0027 mmol) was dissolved in methanol (2 mL), and sodium methoxide (0.07 mg, 0.0013 mmol) was added. The mixture was stirred at room temperature for 24 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0070] It was then dissolved in a mixture of ethyl acetate / methanol / water / acetic acid (1:1:0.5:0.2, v / v, 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction mixture was stirred for 58 h under hydrogen (40 psi). The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography. The lyophilized compound was passed through a Dowex X-8 resin (sodium form) column and eluted with 10 mL of ultrapure water. Lyophilization gave compound 7 (2.74 mg, 0.002 mmol, 75%). 1 H NMR (600 MHz, D2O) δ 5.25 - 5.17 (m, 2H, 1e-H, 1g-H), 5.03(s, 1H, 1d-H), 4.76 - 4.72 (m, 1H, 1b-H), 4.60 - 4.53 (m, 1H, 1a-H), 4.46 (d, J= 7.9 Hz, 1H, 1c-H), 4.34 (s, 1H, 5e-H), 4.27 (s, 1H, 4g-H), 4.21 (s, 2H,2e-H, 4e-H), 4.17 (s, 1H, 3e-H), 4.12 (d, J = 3.9 Hz, 2H, 2a-H, 6a-CH2), 4.08(s, 2H, 4b-H, 2d-H), 4.05 (d, J = 5.8 Hz, 3H, 3d-H, 4d-H, 5g-H ), 4.01 (d, J =5.5 Hz, 5H, 6a-CH2, 1f-H, 2f-H, 4f-H, 3g-H), 3.92 (d, J = 10.2 Hz, 5H, 3a-H,5a-H, 4c-H, 6e-CH2, 5f-H), 3.88 - 3.80 (m, 6H, 5d-H, 1f-H, 3f-H, 6e-CH2, 2g-H), 3.79 - 3.72 (m, 7H, 6b-CH2, 6c-CH2, 6g-CH2), 3.70 - 3.61 (m, 7H, 2b-H, 3b-H, 5b-H, 3c-H, 5c-H, 6d-CH2), 3.52 (d, J = 8.8 Hz, 1H, 2c-H), 2.96 (s, 2H,Linker-CH2), 2.04 (d, J = 4.3 Hz, 3H, NHAc-CH3), 1.63 (d, J = 31.7 Hz, 4H,Linker-CH2), 1.41 (s, 2H, Linker-CH2); 13C NMR (151 MHz, D2O) δ 174.6, 109.1(1e-C), 108.9 (1d-C), 103.4 (1c-C), 103.1 (1b-C), 100.9 (1a-C), 98.9 (1g-C),82.8, 81.4, 81.1, 80.5, 79.2, 78.1, 76.3, 75.8, 75.2, 75.1, 74.7, 74.3, 73.7,72.7, 71.4, 71.3, 70.6, 70.4, 70.0, 69.3, 69.1, 68.5, 66.9, 62.4, 61.1, 61.0,60.8, 59.7, 51.9, 39.3, 28.0, 26.6, 22.1, 22.0; MALDI-TOF (m / z): calcd forC 42 H 76 N2O 33 P - (M+H) - : 1329.4601, found: 1329.4611. The synthesis reaction equation for N-aminopentylβ-D-furanogalactose-(1→3)-β-D-pyranogalactose (2a) is as follows: Figure 5 As shown; Compound 4* (17.6 mg, 0.0156 mmol) was dissolved in a mixture of methanol and tetrahydrofuran (2.5:1, v / v, 2 mL). Sodium methoxide (0.42 mg, 0.0078 mmol) was added, and the mixture was stirred at room temperature for 4 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography. It was then dissolved in methanol (5 mL). 10% palladium on carbon (10 mg) was added, and the mixture was stirred at hydrogen (40 psi) for 12 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography and lyophilized to give compound 2a (4.29 mg, 0.01 mmol, 64%). 1H NMR (600 MHz, D2O) δ 5.12 - 5.05 (m, 1H, 1e-H), 4.38 - 4.29 (m, 1H, 1b-H), 4.10 - 4.05 (m, 1H, 2b-H), 4.00 - 3.91 (m, 3H, 4b-H, 2e-H, 3e-H), 3.90 - 3.68 (m, 5H, 3b-H, 5b-H, 4e-H, Linker-CH2), 3.64 (td, J = 7.2, 6.8, 2.2 Hz, 2H, 6b-CH2), 3.62 - 3.55 (m, 3H, 6e-CH2, Linker-CH2), 3.53- 3.48 (m, 1H, 5e-H), 2.89 (t, J = 7.6 Hz, 2H, Linker-CH2), 1.64 - 1.46 (m,4H, Linker-CH2), 1.35 (p, J = 7.9 Hz, 2H, Linker-CH2); 13 C NMR (151 MHz, D2O) δ109.1 (1e-C), 102.5 (1b-C), 96.4, 82.7, 81.4, 80.4, 76.7, 74.9, 70.6, 69.94,69.88, 68.5, 62.6, 62.4, 60.9, 39.3, 28.1, 26.4, 22.1, 8.2; HR-ESI-MS (m / z):calcd for C 17 H 33 NO 11 Na + (M+Na) + : 450.1946, found: 450.1946. The synthesis reaction equation for N-aminopentylβ-D-galactopyranose-(1→4)-2-N-acetyl-2-deoxy-β-D-galactopyranose (2b) is as follows: Figure 5 As shown; Compound 6* (50.3 mg, 0.047 mmol) was dissolved in a mixture of methanol and tetrahydrofuran (2.5:1, v / v, 2 mL). Sodium methoxide (1.28 mg, 0.024 mmol) was added, and the mixture was stirred at room temperature for 24 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0071] It was then dissolved in a mixture of tert-butanol / water / dichloromethane (5:2:1, v / v; 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction was stirred under hydrogen (40 psi) for 24 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography and lyophilized to give compound 2b (16.0 mg, 0.034 mmol, 72%). 1 H NMR (400 MHz, D2O) δ 4.47 (d, J = 7.1 Hz, 1H, 1b-H), 4.38 (d, J = 8.4Hz, 1H, 1a-H), 4.07 (d, J = 3.0 Hz, 1H, 5a-H), 3.90 - 3.46 (m, 13H, 2a-H, 2b-H, 3a-H, 3b-H, 4a-H, 4b-H, 5b-H, 6a-CH2, 6b-CH2, Linker-CH2), 2.88 (t, J = 7.5Hz, 2H, Linker-CH2), 1.93 (s, 3H, NHAc-CH3), 1.64 - 1.43 (m, 4H, Linker-CH2), 1.37 - 1.22 (m, 2H, Linker-CH2); 13 C NMR (101 MHz, D2O) δ 174.8, 104.4 (1b-C), 101.4 (1a-C), 76.5, 75.1, 74.2, 72.7, 71.5, 71.4, 70.0, 68.6, 61.3, 61.0,60.5, 53.0, 39.4, 34.6, 30.7, 29.8, 28.1, 26.5, 26.4, 25.5, 25.0, 22.2, 22.1,22.0; HR-ESI-MS (m / z): calcd for C 19 H 36 N2O 11 Na + (M+Na) + : 491.2212, found:491.2231. The synthesis reaction equation for N-aminopentyl α-D-pyranogalactose-D-ribitol phosphonate sodium salt (2c) is as follows: Figure 5 As shown; Compound 26* (11.2 mg, 0.008 mmol) was dissolved in a mixture of ethyl acetate / methanol / water / acetic acid (v / v ratio 1:1:0.5:0.2, 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction mixture was stirred at hydrogen (40 psi) for 36 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography. The lyophilized compound was passed through a Dowex X-8 resin (sodium form) column and eluted with 10 mL of ultrapure water. Lyophilization gave compound 2c (3.4 mg, 0.007 mmol, 85%). 1 H NMR (600 MHz, D2O) δ 5.17 (s, 1H, 1g-H), 4.03 - 3.92 (m, 4H, 5g-H, 6g-CH2, 5f-CH2, Linker-CH2), 3.92 - 3.83 (m, 5H, 3g-H, 2f-H, 4f-H, 5f-CH2), 3.82 - 3.74 (m, 3H, 2g-H, 3f-H, Linker-CH2), 3.68 (dt, J = 5.1, 2.4 Hz, 2H, CH2), 2.97 (t, J = 6.4 Hz, 2H, Linker-CH2), 1.71 - 1.60(m, 4H, Linker-CH2), 1.43 (t, J = 8.0 Hz, 2H, Linker-CH2); 13 C NMR (151 MHz, D2O)δ 99.0 (1g-C), 79.3, 71.6, 71.4, 70.5, 69.5, 69.2, 68.6, 66.7, 65.8, 61.0,59.8, 39.4, 29.2, 29.1, 26.3, 22.0; HR-ESI-MS (m / z): calcd for C 16 H 33 NO 13 P - (M+H) - : 478.1695, found: 478.1703. The synthesis reaction equation for N-aminopentylβ-D-galactopyranose-(1→4)-[β-D-galactopyranose-(1→3)]-2-N-acetyl-2-deoxy-β-D-galactopyranose (3b) is as follows: Figure 5 As shown; Compound 11* (14.3 mg, 0.0094 mmol) was dissolved in a mixture of methanol and tetrahydrofuran (2.5:1, v / v, 2 mL). Sodium methoxide (0.25 mg, 0.0047 mmol) was added, and the mixture was stirred at room temperature for 24 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0072] The mixture was then dissolved in methanol (5 mL). 10% palladium on carbon (10 mg) was added, and the reaction was stirred under hydrogen (40 psi) for 20 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography and lyophilized to give compound 3b (3.54 mg, 0.0056 mmol, 60% yield). 1 H NMR (600 MHz, D2O) δ5.05 (s, 1H, 1d-H), 4.68 (d, J = 7.7 Hz, 1H, 1b-H), 4.55 (d, J = 8.5 Hz, 1H, 1a-H), 4.25 (d, J = 2.9 Hz, 1H, 2b-H), 4.14 - 4.00 (m, 4H, 2a-H, 4a-H, 4b-H,3d-H), 3.95 - 3.89 (m, 3H, 2d-H, 5d-H, Linker-CH2), 3.85 (dd, J = 11.9, 7.1Hz, 3H, 6a-CH2, 3b-H, 5b-H), 3.78 (d, J = 7.7 Hz, 2H, 6b-CH2), 3.73 (d, J = 6.3Hz, 2H, 6a-CH2, 3a-H), 3.68 - 3.57 (m, 4H, 5a-H, 4d-H, 6d-CH2, Linker-CH2), 3.10 - 2.95 (m, 2H, Linker-CH2), 2.05 (s, 3H, NHAc-CH3), 1.72 - 1.65 (m, 2H,Linker-CH2), 1.62 (t, J = 7.3 Hz, 2H, Linker-CH2), 1.42 (t, J = 7.8 Hz, 2H, Linker-CH2); 13C NMR (151 MHz, D2O) δ 174.6, 109.1 (1d-C), 103.7 (1b-C), 101.0 (1a-C), 82.6, 81.1, 78.3, 76.2, 75.1, 74.9, 74.1, 72.6, 71.0, 70.3, 69.9,68.5, 62.4, 60.9, 60.3, 52.0, 39.2, 34.5, 29.7, 28.0, 26.3, 25.4, 24.9, 23.2,22.1, 22.0; HR-ESI-MS (m / z): calcd for C 25 H 46 N2O 16 Na + (M+Na) + : 653.2740, found:653.2747. The synthesis reaction equation for N-aminopentylβ-D-furanogalactose-(1→3)-β-D-pyranogalactose-(1→4)-2-N-acetyl-2-deoxy-β-D-pyranogalactose (3c) is as follows: Figure 5 As shown; Compound 7* (13.8 mg, 0.009 mmol) was dissolved in a mixture of methanol and tetrahydrofuran (2.5:1, v / v, 2 mL). Sodium methoxide (0.24 mg, 0.0045 mmol) was added, and the mixture was stirred at room temperature for 24 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0073] It was then dissolved in methanol (5 mL). 10% palladium on carbon (10 mg) was added, and the reaction was stirred under hydrogen (40 psi) for 12 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography and lyophilized to give compound 3c (3.4 mg, 0.0054 mmol, 60%). 1 H NMR (600 MHz, D2O) δ 5.19(s, 1H, 1e-H), 4.62 (s, 1H, 1b-H), 4.46 (d, J = 8.5 Hz, 1H, 1a-H), 4.17 (s,2H, 3a-H, 2b-H), 4.07 - 4.00 (m, 3H, 4b-H, 2e-H, 5e-H) 3.94 (t, J= 9.6 Hz,1H, 2a-H), 3.91 - 3.82 (m, 3H, 4a-H, 6b-CH2, Linker-CH2), 3.82 - 3.73 (m, 6H,6a-CH2, 6b-CH2, 3e-H, 4e-H), 3.68 (p, J = 4.1 Hz, 2H, 5a-H, 6e-CH2), 3.65 -3.54 (m, 3H, 3b-H, 5b-H, 6e-CH2), 2.97 (t, J = 7.9 Hz, 2H, Linker-CH2), 2.02(s, 3H, NHAc-CH3), 1.65 (t, J = 7.8 Hz, 2H, Linker-CH2), 1.58 (t, J = 7.3 Hz, 2H, Linker-CH2), 1.42 - 1.35 (m, 2H, Linker-CH2); 13 C NMR (151 MHz, D2O) δ113.4, 109.1 (1e-C), 104.3 (1b-C), 104.2 (1b-C), 101.4 (1a-C), 82.7, 81.4,80.2, 76.6, 76.4, 75.1, 74.9, 74.1, 72.7, 71.5, 71.4, 71.3, 70.6, 70.5, 69.9,68.52, 68.47, 62.6, 61.0, 60.9, 60.5, 60.4, 53.00, 52.95, 39.3, 28.0, 26.3,22.1; HR-ESI-MS (m / z): calcd for C 25 H 46 N2O 16 Na + (M+Na) + : 653.2740, found:653.2761. The synthesis reaction equation for N-aminopentyl α-D-galactopyranose-(1→2)-D-ribitol phosphonate-(5→5)-β-D-galactopyranose sodium salt (3d) is as follows: Figure 5 As shown; Compound 27* (20.0 mg, 0.011 mmol) was dissolved in a mixture of ethyl acetate / methanol / water / acetic acid (v / v ratio 1:1:0.5:0.2, 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction mixture was stirred at hydrogen (40 psi) for 36 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography. The lyophilized compound was passed through a Dowex X-8 resin (sodium form) column and eluted with 10 mL of ultrapure water. Lyophilization gave compound 3d (5.8 mg, 0.009 mmol, 80%). 1 H NMR (600 MHz, D2O) δ 5.24 - 5.16 (m, 1H,1g-H), 5.03 - 4.92 (m, 1H, 1e-H), 4.31 (dd, J = 9.0, 4.5 Hz, 1H, 3g-H), 4.19 -4.07 (m, 3H, 3f-H, 3e-H, Linker-CH2), 4.05 - 3.96 (m, 6H, 4g-H, 2f-H, 2e-H,4e-H, Linker-CH2), 3.93 - 3.87 (m, 2H, 5g-H, f-CH2), 3.86 - 3.79 (m, 3H, 2g-H,2f-H, 2e-H), 3.76 (dd, J = 10.5, 4.9 Hz, 3H, 6g-CH2, 6f-CH2), 3.73 (d, J = 5.8Hz, 2H, 5f-CH2), 3.63 - 3.55 (m, 1H, 6g-CH2), 3.04 - 2.88 (m, 2H, Linker-CH2), 1.74 - 1.59 (m, 4H, Linker-CH2), 1.47 - 1.37 (m, 2H, Linker-CH2); 13 C NMR (151MHz, D2O) δ 106.8 (1e-C), 98.9 (1g-C), 81.0, 79.2, 75.7, 74.7, 74.6, 71.4,71.3, 70.4, 70.3, 69.3, 69.1, 68.5, 68.1, 66.89, 66.85, 61.1, 61.0, 59.7,39.3, 28.0, 26.5, 22.1; HR-ESI-MS (m / z): calcd for C22 H 43 NO 18 P - (M+H) - : 640.2223, found: 640.2241 The synthesis reaction equation for N-aminopentylβ-D-galactofuranose-(1→3)-β-D-galactopyranose-(1→4)-[β-D-galactopyranose-(1→6)]-2-N-acetyl-2-deoxy-β-D-galactopyranose (4a) is as follows: Figure 5 As shown; Compound 14* (14.3 mg, 0.0076 mmol) was dissolved in a mixture of methanol and tetrahydrofuran (2.5:1, v / v, 2 mL). Sodium methoxide (0.21 mg, 0.0038 mmol) was added, and the mixture was stirred at room temperature for 48 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0074] The mixture was then dissolved in methanol (5 mL). 10% palladium on carbon (10 mg) was added, and the reaction was stirred under hydrogen (40 psi) for 24 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography and lyophilized to give compound 4a (3.38 mg, 0.0043 mmol, 56%). 1 H NMR (600 MHz, D2O) δ 5.08(d, J = 1.9 Hz, 1H, 1e-H), 4.47 (dd, J = 37.0, 7.0 Hz, 1H, 1b-H), 4.35 (dd, J =14.1, 8.2 Hz, 2H, 1a-H, 1c-H), 4.11 - 4.00 (m, 3H, 3a-H, 2b-H, Linker-CH2), 3.97 - 3.90 (m, 2H, 4c-H, 2e-H), 3.89 - 3.82 (m, 2H, 2a-H, Linker-CH2), 3.81- 3.74 (m, 4H, 4a-H, 2c-H, 3c-H, 6c-CH2), 3.71 - 3.66 (m, 3H, 3b-H, 4b-H, 3e-H), 3.66 - 3.59 (m, 4H, 6a-CH2, 6b-CH2), 3.56 (t, J= 4.1 Hz, 2H, 5a-H, 6e-CH2), 3.54 - 3.45 (m, 5H, 5b-H, 5c-H, 6c-CH2, 4e-H, 6e-CH2), 3.39 (dd, J = 9.9,7.8 Hz, 1H, 5e-H), 2.86 (t, J = 7.7 Hz, 2H, Linker-CH2), 1.91 (s, 3H, NHAc-CH3), 1.55 (t, J = 7.7 Hz, 2H, Linker-CH2), 1.48 (t, J = 7.3 Hz, 2H, Linker-CH2), 1.34 - 1.23 (m, 2H, Linker-CH2); 13 C NMR (151 MHz, D2O) δ109.0 (1e-C),104.1 (1b-C), 103.4 (1c-C), 101.3 (1a-C), 82.6, 81.3, 76.7, 76.6, 75.1, 75.0,74.8, 73.6, 72.6, 71.4, 70.6, 70.0, 68.5, 62.5, 60.9, 60.8, 52.8, 39.2, 28.0,26.3, 22.1; HR-ESI-MS (m / z): calcd for C 31 H 56 N2O 21 Na + (M+Na) + : 815.3268, found:815.3281. The synthesis reaction equation for N-aminopentylβ-D-galactopyranose-(1→4)-[β-D-galactopyranose-(1→6)]-[β-D-galactofuranose-(1→3)]-2-N-acetyl-2-deoxy-β-D-galactopyranose (4b) is as follows: Figure 5 As shown; Compound 25* (20.5 mg, 0.01 mmol) was dissolved in a mixture of methanol and tetrahydrofuran (2.5:1, v / v, 2 mL). Sodium methoxide (0.29 mg, 0.005 mmol) was added, and the mixture was stirred at room temperature for 48 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0075] It was then dissolved in methanol (5 mL). 10% palladium on carbon (10 mg) was added, and the reaction was stirred under hydrogen (40 psi) for 24 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography and lyophilized to give compound 4b (4.66 mg, 0.0059 mmol, 55%). 1 H NMR (600 MHz, D2O) δ 4.99(d, J = 2.2 Hz, 1H, 1d-H), 4.63 (d, J = 7.7 Hz, 1H, 1b-H), 4.51 (d, J = 8.8 Hz, 1H, 1a-H), 4.42 (d, J = 7.8 Hz, 1H, 1c-H), 4.21 (d, J = 3.0 Hz, 1H, 2b-H), 4.13- 3.98 (m, 5H, 2a-H, 2c-H, 3c-H, 4d-H, Linker-CH2), 3.94 (dd, J = 11.9, 8.3Hz, 1H, Linker-CH2), 3.91 - 3.84 (m, 4H, 3a-H, 3b-H, 2d-H, 6d-CH2), 3.82 -3.77 (m, 2H, 4a-H, 4b-H), 3.75 - 3.68 (m, 4H, 6a-CH2, 6b-CH2), 3.67 - 3.55 (m,6H, 5a-H, 5b-H, 4c-H, 5c-H, 6c-CH2, 6d-CH2), 3.50 (m, J = 23.1, 9.9, 7.7 Hz,2H, 3d-H, 5d-H), 2.95 (t, J = 7.6 Hz, 2H, Linker-CH2), 2.00 (s, 3H, NHAc-CH3),1.64 (t, J = 7.7 Hz, 2H, Linker-CH2), 1.58 (t, J = 7.4 Hz, 2H, Linker-CH2), 1.37(dd, J = 11.3, 4.6 Hz, 2H, Linker-CH2); 13C NMR (151 MHz, D2O) δ 174.6, 109.1(1d-C), 103.4 (1b-C, 1c-C), 100.9 (1a-C), 82.7, 81.1, 78.2, 76.3, 75.3, 75.1,74.8, 73.7, 72.7, 71.2, 70.6, 70.4, 70.0, 68.5, 62.4, 61.0, 60.8, 51.9, 39.3,29.8, 28.0, 26.3, 22.1, 22.0; HR-ESI-MS (m / z): calcd for C 31 H 56 N2O 21 Na + (M+Na) + :815.3268, found: 815.3277. The synthesis reaction equation for N-aminopentylβ-D-galactofuranose-(1→3)-β-D-galactopyranose-(1→4)-[β-D-galactopyranose-(1→6)]-[β-D-galactofuranose-(1→3)]-2-N-acetyl-2-deoxy-β-D-galactopyranose (5a) is as follows: Figure 5 As shown; Compound 22* (17.7 mg, 0.0079 mmol) was dissolved in a mixture of methanol and tetrahydrofuran (2.5:1, v / v, 2 mL). Sodium methoxide (0.21 mg, 0.004 mmol) was added, and the mixture was stirred at room temperature for 56 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0076] It was then dissolved in methanol (5 mL). 10% palladium on carbon (10 mg) was added, and the reaction was stirred under hydrogen (40 psi) for 36 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography and lyophilized to give compound 5a (3.60 mg, 0.0038 mmol, 48%). 1 H NMR (600 MHz, D2O) δ 5.19(s, 1H, 1e-H), 5.01 (s, 1H, 1d-H), 4.70 (s, 1H, 1b-H), 4.53 (d, J = 8.4 Hz, 1H, 1a-H), 4.44 (d, J= 7.7 Hz, 1H, 1c-H), 4.27 - 4.14 (m, 1H, 2b-H), 4.09 (d, J = 14.6 Hz, 1H, 2d-H), 4.02 (d, J = 11.3 Hz, 6H, 2a-H, 3a-H, 3c-H, 3d-H,Linker-CH2), 3.96 (s, 1H, 2c-H), 3.90 (s, 3H, 5a-H, 3c-H, 2e-H), 3.82 (d, J =15.3 Hz, 4H, 4a-H, 3b-H, 3e-H, 4e-H), 3.73 (dd, J = 24.5, 8.1 Hz, 6H, 6a-CH2,4b-H, 5b-H, 6d-CH2), 3.68 - 3.60 (m, 9H, 6b-CH2, 5c-H, 6c-CH2, 4d-H, 5d-H, 6e-CH2), 3.01 - 2.93 (m, 2H, Linker-CH2), 2.02 (s, 3H, NHAc-CH3), 1.68 - 1.63 (m,2H, Linker-CH2), 1.61 - 1.55 (m, 2H, Linker-CH2), 1.39 (t, J = 7.6 Hz, 2H,Linker-CH2); 13 C NMR (151 MHz, D2O) δ 174.7, 109.2 (1d-C, 1e-C), 103.5 (1b-C,1c-C), 101.1 (1a-C), 82.9, 81.2, 78.3, 76.4, 75.2, 73.8, 72.8, 70.7, 70.5,70.1, 68.6, 62.5, 61.0, 60.9, 52.0, 39.4, 28.1, 26.4, 22.1; HR-ESI-MS (m / z):calcd for C 37 H 66 N2O 26 Na + (M+Na) + : 977.3796, found: 977.3800. The synthesis reaction equation for N-aminopentyl α-D-galactopyranose-(1→2)-D-ribitol phosphonate-(5→5)-β-D-galactopyranose-(1→3)-β-D-galactopyranose-(1→4)-[β-D-galactopyranose-(1→3)]-2-N-acetyl-2-deoxy-β-D-galactopyranose sodium salt (6b) is as follows: Figure 5 As shown; Compound 28* (6.3 mg, 0.0022 mmol) was dissolved in methanol (2 mL), and sodium methoxide (0.06 mg, 0.0011 mmol) was added. The mixture was stirred at room temperature for 12 h. After the reaction was completed as monitored by TLC, the solution was neutralized with hydrogen ion exchange resin and filtered. The crude product was purified by silica gel column chromatography.

[0077] It was then dissolved in a mixture of ethyl acetate / methanol / water / acetic acid (v / v ratio 1:1:0.5:0.2, 5 mL). 10% palladium on carbon (10 mg) was added, and the reaction mixture was stirred at hydrogen (40 psi) for 36 h. The reaction mixture was filtered through diatomaceous earth, and the filtrate was concentrated. The crude product was purified by Sephadex LH-20 (water) column chromatography. The lyophilized compound was passed through a Dowex X-8 resin (sodium form) column and eluted with 10 mL of ultrapure water. Lyophilization gave compound 6b (1.8 mg, 0.0015 mmol, 68%). 1 H NMR (600 MHz, D2O) δ 5.12 (d, J = 7.6 Hz, 2H, 1g-H, 1e-H), 4.94 (s, 1H, 1d-H), 4.64 (d, J = 7.4 Hz, 1H, 1b-H), 4.44 (d, J = 8.3 Hz, 1H,1a-H), 4.24 (s, 1H, 3a-H), 4.16 (s, 1H, 2b-H), 4.11 (s, 2H, 2d-H, 4d-H), 4.07(d, J = 6.7 Hz, 1H, 3g-H), 4.03 - 3.87 (m, 10H, 2a-H, 4a-H, 3b-H, 2e-H, 4e-H,2f-H, 3g-H, Linker-CH2), 3.86 - 3.78 (m, 3H, 6a-CH2, 3d-H), 3.78 - 3.70 (m,5H, 5a-H, 4b-H, 6d-CH2, 3f-H), 3.65 (t, J= 7.3 Hz, 5H, 6b-CH2, 3e-H, 6e-CH2),3.61 - 3.56 (m, 3H, 5b-H, 6g-CH2), 3.53 (d, J = 8.9 Hz, 2H, 5f-CH2), 3.25 (s,1H, 5g-H), 3.16 (s, 1H, 4f-H), 2.85 (s, 2H, Linker-CH2), 1.95 (s, 3H, NHAc-CH3), 1.55 (s, 2H, Linker-CH2), 1.50(d, J = 7.0 Hz, 2H, Linker-CH2), 1.31 (s,2H, Linker-CH2); 13 C NMR (151 MHz, D2O) δ 108.9 (1d-C, 1e-C), 103.4 (1b-C), 101.0 (1a-C), 98.9 (1g-C), 82.7, 81.1, 80.4, 79.2, 78.3, 76.2, 75.8, MALDI-TOF (m / z): calcd for C 42 H 76 N2O 33 P - (M+H) - : 1167.4073, found:1167.4077. Example 3 Preparation and antigenic screening of sugar chips, such as Figure 6 As shown.

[0078] Specific experimental procedures and steps: Each oligosaccharide fragment, as well as unrelated oligosaccharides, unrelated natural capsular polysaccharides, carrier proteins, natural Streptococcus pneumoniae 10A serotype capsular polysaccharides, and polysaccharide-protein conjugates, were dissolved in 50 mM sodium phosphate buffer with a pH of 8.5. The spotting concentrations of the synthesized oligosaccharide fragments were 2 mM and 5 mM, and the spotting concentrations of the polysaccharides and carrier proteins were 4 μg / mL and 10 μg / mL, respectively.

[0079] NHS activated slides (SurModics, DN01-0025) were used as the chip substrate, and samples were spotted using a biochip spotting instrument (Jiangsu Ruiming Biotechnology Co., Ltd.) according to a preset spotting matrix. After spotting, the slides were incubated overnight at 26℃ and 55% relative humidity to allow oligosaccharide fragments or control samples to fully bind to the slide surface. Subsequently, the slides were immersed in quenching buffer (50 nM Na2HPO4, 100 nM ethanolamine aqueous solution) and incubated at 50℃ for 1 hour to block unreacted active sites. After quenching, the slides were washed three times with ultrapure water and centrifuged to remove residual water. Then, the slides were blocked with 3% BSA in PBS solution and incubated at room temperature for 1 hour. After blocking, the slides were washed once with PBST solution and twice with PBS solution, and centrifuged to dry. The treated slides were then placed into 16-well incubators, and 120 μL of diluted rabbit serum sample was added to each well. The rabbit serum sample was diluted 1:50 with PBS solution containing 1% BSA and then incubated overnight in a humidified chamber at 4°C in the dark to allow the specific IgG antibodies in the serum to bind to the oligosaccharide fragments on the chip surface. After incubation, the serum sample was removed and washed three times with PBST solution to remove unbound serum antibodies. Alexa Fluor was then added. TM 532-labeled goat anti-rabbit IgG antibody (Invitrogen) was used as the secondary antibody and incubated in a humidified chamber at 37 °C for 1 hour in the dark. After incubation, the secondary antibody solution was removed, the chip was washed three times with PBST solution, the incubation mold was removed, and the chip was washed once with ultrapure water, followed by immersion in ultrapure water for 15 minutes to obtain the oligosaccharide chip for detection. Finally, the chip was scanned for fluorescence using a chip scanner (LuxScan 10K / B, Chengdu Biochip Biotechnology Co., Ltd.), and the fluorescence signal was quantitatively analyzed using image analysis software (GenePix Pro 6.0). The detection results are shown in Figure 6. The combined results of the three antisera show that different oligosaccharide fragments exhibit significantly different antibody recognition profiles. The intact heptaose 7 showed the strongest binding signal in the bacterial antiserum, indicating that it can well mimic the antigenic structure of the capsular polysaccharide of natural Streptococcus pneumoniae serotype 10A. The hexaose 6a showed strong binding signals in all three antiserum tests, suggesting that it has relatively stable antigen recognition ability. The pentasaccharide 5b was also recognized by all three antiserums and showed a strong binding signal in the capsular polysaccharide antiserum test.

[0080] From the perspective of the smallest recognizable structure, trisaccharide 3a is the smallest non-phosphorylated oligosaccharide fragment capable of generating a significant binding signal; while tetrasaccharide 4c is a smaller structure that can still maintain a good antibody recognition signal among oligosaccharide fragments containing phosphate groups. No significant fluorescence signal was observed in the negative control group, indicating that the antiserum has good specificity for recognizing synthetic oligosaccharide fragments.

[0081] Based on the above results, this invention screened from two dimensions: "strong binding candidate structure" and "minimum identifiable structure", and identified trisaccharide 3a, tetrasaccharide 4c, pentasaccharide 5b, hexasaccharide 6a and heptasaccharide 7 as highly antigenic oligosaccharide fragments, which can be used for subsequent preparation of glycoprotein conjugates and immunogenicity evaluation.

[0082] Example 4: Preparation of a glycoprotein conjugate of a highly antigenic oligosaccharide fragment and CRM197 This embodiment prepares a glycoprotein conjugate of a highly antigenic Streptococcus pneumoniae serotype 10A synthetic oligosaccharide fragment and the carrier protein CRM197, as shown in Figure 7A. The highly antigenic oligosaccharide fragment includes trisaccharide 3a, tetrasaccharide 4c, pentasaccharide 5b, hexasaccharide 6a, and heptasaccharide 7 obtained through glycochip screening.

[0083] Specific experimental procedures and steps: (1) Activation of synthetic oligosaccharide fragments 1.0 mg of the synthetic oligosaccharide antigen was dissolved in 0.3 mL of dimethyl sulfoxide (DMSO). Then, 3-maleimide propionate N-hydroxysuccinimide ester dissolved in 0.2 mL of DMSO was added under stirring. The molar ratio of 3-maleimide propionate N-hydroxysuccinimide ester to the synthetic oligosaccharide antigen was 6:1. The reaction was carried out at room temperature for 10 hours. After the reaction was complete, the sample was purified by Sephadex LH-20 column chromatography using water as the eluent. The fraction containing the target product was collected and concentrated under reduced pressure to obtain the maleimide-activated synthetic oligosaccharide antigen.

[0084] (2) Thiolation treatment of carrier protein CRM197 1 mg of the carrier protein CRM197 was dissolved in 1 mL of PBS buffer (pH 8.0) containing 1.86 mg / mL EDTA. Under argon protection, disulfide bis(succinimide propionate) dissolved in 50 μL of dimethyl sulfoxide was added. The molar ratio of disulfide bis(succinimide propionate) to CRM197 was 8:1. The reaction was carried out at room temperature for 8 hours. After the reaction was complete, the reaction system was placed in an ice bath, and dithiothreitol was added under argon protection to a final concentration of 0.025 mmol / mL. The reaction was then carried out at 0 °C for 3 hours to reduce the introduced disulfide bonds and obtain thiolized CRM197. The reaction solution was then diluted with PBS buffer (pH 7.2) containing 1.86 mg / mL EDTA. The resulting mixture was placed in a 30 kDa ultrafiltration membrane and washed three times with the same PBS buffer to remove unreacted small molecule reagents and reducing agents, yielding a thiolized CRM197 solution. The resulting solution was stored at 0 °C and used for subsequent coupling reactions.

[0085] (3) Coupling of synthetic oligosaccharide fragments with CRM197 The maleimide-activated synthetic oligosaccharide fragment obtained in step (1) was dissolved in 0.5 mL of PBS buffer with a pH of 7.2. Under stirring, this was added to the thiolated CRM197 solution obtained in step (2), which was pre-dissolved in 2 mL of PBS buffer with a pH of 7.2 and containing 1.86 mg / mL EDTA. The reaction system was incubated at 4–8 °C for 6 hours to allow the maleimide groups in the activated oligosaccharide fragment to couple with the thiol groups on the surface of the thiolated CRM197. After the reaction was complete, 0.1 mg of N-ethylmaleimide was added to terminate the reaction and block the unreacted thiol groups. The reaction solution was then diluted with PBS buffer with a pH of 7.2. The resulting mixture was placed in a 30 kDa ultrafiltration membrane and washed three times with PBS buffer to remove uncoupled oligosaccharides, small molecule linkers and other impurities, to obtain the synthetic oligosaccharide-CRM197 glycoprotein conjugate of Streptococcus pneumoniae 10A serotype.

[0086] Following the above method, five oligosaccharide-carrier protein conjugates of Streptococcus pneumoniae serotype 10A were prepared, namely trisaccharide glycoprotein 3a-CRM197, tetrasaccharide glycoprotein 4c-CRM197, pentasaccharide glycoprotein 5b-CRM197, hexasaccharide glycoprotein 6a-CRM197, and heptasaccharide glycoprotein 7-CRM197.

[0087] As shown in Figure 7B, SDS-PAGE results indicated that, compared to unmodified CRM197, the protein bands of all five oligosaccharide-CRM197 conjugates showed varying degrees of molecular weight increase and band broadening, indicating that CRM197 successfully linked the corresponding oligosaccharide residues to form glycoprotein conjugates. Further analysis of the SDS-PAGE bands using Quantity One software (Bio-Rad) estimated the average molecular weight of the five glycoprotein conjugates. The results showed that the average molecular weight of the trisaccharide glycoprotein conjugate 3a-CRM197 was 66.0 kDa, the average molecular weight of the tetrasaccharide glycoprotein conjugate 4c-CRM197 was 73.2 kDa, the average molecular weight of the pentasaccharide glycoprotein conjugate 5b-CRM197 was 72.2 kDa, the average molecular weight of the hexasaccharide glycoprotein conjugate 6a-CRM197 was 71.0 kDa, and the average molecular weight of the heptasaccharide glycoprotein conjugate 7-CRM197 was 64.0 kDa. Based on the above average molecular weight results, and combined with the molecular weights of the CRM197 carrier protein and the corresponding oligosaccharide residues, the average number of oligosaccharide residues linked to each CRM197 molecule in each glycoprotein conjugate was calculated as follows: 3a-CRM197: 6.0, 4c-CRM197: 12.7, 5b-CRM197: 12.2, 6a-CRM197: 7.5, and 7-CRM197: 2.4. These results indicate that this embodiment successfully prepared five structurally defined synthetic oligosaccharide-CRM197 conjugates for Streptococcus pneumoniae serotype 10A. The obtained conjugates can be used for subsequent animal immunogenicity evaluation.

[0088] Example 5 Screening for the immunogenicity of synthetic oligosaccharide-CRM197 glycoprotein conjugates from Streptococcus pneumoniae serotype 10A, such as... Figure 8 As shown.

[0089] To further evaluate the ability of highly antigenic oligosaccharide fragments obtained through oligosaccharide chip screening to induce specific immune responses in animals, this example used the trisaccharide glycoprotein 3a-CRM197, tetrasaccharide glycoprotein 4c-CRM197, pentasaccharide glycoprotein 5b-CRM197, hexasaccharide glycoprotein 6a-CRM197, and heptasaccharide glycoprotein 7-CRM197 prepared in Example 4 for animal immunization experiments, and the level of Streptococcus pneumoniae 10A serotype-specific antibodies in the antiserum after immunization was detected.

[0090] Specifically, each synthetic oligosaccharide-CRM197 glycoprotein conjugate was emulsified with Freund's adjuvant at a 1:1 volume ratio to prepare the immunizing agents. A system obtained by mixing PBS and Freund's adjuvant in the same proportion served as a negative control. Four New Zealand white rabbits were used in each group for subcutaneous injection. The injection dose per animal, calculated based on the oligosaccharide content, was 5 μg / animal. The immunization program included a primary immunization and multiple booster immunizations, with an interval of approximately 2 weeks between adjacent immunizations. Serum was collected after the final immunization, and the resulting antiserum was used for subsequent immunological analysis.

[0091] Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the levels of specific IgG antibodies in the antisera of each group. Purified polysaccharide from the natural capsular polysaccharide of Streptococcus pneumoniae 10A serotype and a polysaccharide-protein conjugate of Streptococcus pneumoniae 10A serotype were used as coating antigens to detect the antibodies in each group of immune sera. During the assay, the coating antigen was immobilized on the surface of an ELISA plate, blocked, and then serially diluted immune sera were added to allow the specific antibodies in the serum to bind to the coating antigen. Subsequently, enzyme-labeled secondary antibody was added for a colorimetric reaction, and the absorbance was measured to evaluate the recognition ability of each group of antisera against the Streptococcus pneumoniae 10A serotype glycoantigen.

[0092] The test results are shown in Figure 8. Compared with the PBS negative control group, all the synthetic oligosaccharide-CRM197 glycoprotein conjugate immunization groups were able to induce different degrees of Streptococcus pneumoniae 10A serotype-specific IgG antibody responses, indicating that the synthetic oligosaccharide fragments can be converted into immunogenic glycoprotein antigens after conjugation with the carrier protein. The antibody levels induced by the glycoprotein conjugates corresponding to different oligosaccharide fragments differed, indicating that oligosaccharide chain length, phosphodiester bonds, branching structure, and terminal glycosyl composition all affect their immunogenicity. Combining the test results of the two coated antigen systems, the trisaccharide glycoprotein 3a-CRM197 and hexasaccharide glycoprotein 6a-CRM197 immunization groups induced relatively high levels of specific IgG antibody binding, indicating that trisaccharide 3a and hexasaccharide 6a have good immunogenicity. Heptasaccharide glycoprotein 7-CRM197 showed differentiated antibody binding results in different coated antigen systems, suggesting that its immune recognition effect may be affected by the oligosaccharide spatial conformation, epitope exposure degree, or conjugation mode with the carrier protein CRM197.

[0093] Further analysis was conducted using a glycan microarray to examine the cross-recognition ability of each group of immune antisera on different synthetic oligosaccharide fragments. The results are as follows: Figure 9 As shown, the IgG antibodies generated by the immunization groups of each glycoprotein conjugate could recognize their corresponding oligosaccharide fragments, indicating that the synthetic oligosaccharide-CRM197 conjugate can induce specific antibody responses against the corresponding sugar epitopes. Specifically, the pentasaccharide glycoprotein 5b-CRM197 and hexasaccharide glycoprotein 6a-CRM197 immune sera showed broad recognition capabilities for multiple oligosaccharide fragments; the trisaccharide glycoprotein 3a-CRM197 and heptasaccharide glycoprotein 7-CRM197 immune sera also showed some cross-recognition capability; the overall recognition signal of the tetrasaccharide glycoprotein 4c-CRM197 immune sera was relatively weak. These results indicate that different synthetic oligosaccharide fragments differ in inducing antibody cross-recognition, and their immunogenicity is related not only to glycan length but also to specific epitope conformations, phosphodiester bonds, branching structures, and terminal glycosyl composition.

[0094] Based on the combined analysis of ELISA and glycan microarray detection structures, the glycoprotein conjugate corresponding to the hexasaccharide 6a exhibits strong immunogenicity and a broad oligosaccharide recognition spectrum, making it a potential candidate antigen. The trisaccharide 3a represents a smaller candidate antigenic epitope structure and has further development potential. The pentasaccharide 5b induces a broad antibody recognition spectrum and can serve as an important candidate oligosaccharide fragment. The heptasaccharide 7 represents a complete repeating unit structure and can be used as a control or candidate antigen fragment. Although the tetrasaccharide 4c shows some recognition ability in glycan microarray antigenicity screening, the immune response induced by its corresponding glycoprotein conjugate is relatively weak.

[0095] Therefore, this invention screened and identified trisaccharide 3a, pentasaccharide 5b, hexasaccharide 6a, and heptasaccharide 7 as oligosaccharide fragments of capsular polysaccharides of Streptococcus pneumoniae 10A serotype with good immunogenicity, which can be used in the preparation of Streptococcus pneumoniae glycoprotein conjugates and Streptococcus pneumoniae vaccines.

[0096] The above results demonstrate that the chemically synthesized oligosaccharide fragments and their glycoprotein conjugates of Streptococcus pneumoniae 10A serotype provided by this invention can be used for the preparation of Streptococcus pneumoniae glycoprotein conjugates and Streptococcus pneumoniae vaccines, and provide experimental basis for the structural optimization and quality-controlled preparation of the antigen of this serotype vaccine.

[0097] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. The use of an oligosaccharide compound of Streptococcus pneumoniae serotype 10A or its pharmaceutically acceptable salt, free base, zwitterion, or lyophilized powder in the preparation of a Streptococcus pneumoniae vaccine, characterized in that, The oligosaccharide compound of Streptococcus pneumoniae 10A serological type is selected from any one or more of the following: Where Z is an empty key or ; R1, R2, and R3 are each independently selected from H, ; R4 is independently selected from H, ; M is either Na or K; Linker is a connecting arm, selected from -(CH2). n -NH2、-(CH2) n -SH, azide-based linker, alkynyl-based linker, maleimide reactive linker or its derivatives; n is 2-40.

2. A pneumococcal 10A serotype oligosaccharide compound or its pharmaceutically acceptable salt, free base, zwitterion, or lyophilized powder for use in the preparation of pneumococcal conjugate vaccines, characterized in that, The structure of the compound is shown in formula (A) or formula (B): ， Where Z is an empty key or ; R1, R2, and R3 are each independently selected from H, ; R4 is independently selected from H, ; M is either Na or K; Linker is a connecting arm, selected from -(CH2). n -NH2、-(CH2) n -SH, azide-based linker, alkynyl-based linker, maleimide reactive linker or its derivatives; n is 2-40.

3. The oligosaccharide compound of Streptococcus pneumoniae serotype 10A according to claim 2, or its pharmaceutically acceptable salt, free base, zwitterion, or lyophilized powder, is characterized in that... The oligosaccharide compounds of Streptococcus pneumoniae serotype 10A are selected from any one or more of the following: 。 4. The oligosaccharide compound of Streptococcus pneumoniae serotype 10A according to claim 2, or its pharmaceutically acceptable salt, free base, zwitterion, or lyophilized powder, is characterized in that, The oligosaccharide compounds of Streptococcus pneumoniae serotype 10A are specifically selected from any one or more of the following: 。 5. The oligosaccharide compound of Streptococcus pneumoniae serotype 10A according to claim 2, or its pharmaceutically acceptable salt, free base, zwitterion, or lyophilized powder, is characterized in that... The pharmaceutically acceptable salt forms include, but are not limited to, hydrochloride, acetate, phosphate, citrate, lactate, tartrate, sodium salt, potassium salt, and ammonium salt.

6. A sugar chip, characterized in that, Includes a chip substrate and an oligosaccharide compound of Streptococcus pneumoniae 10A serotype as described in any one of claims 2-5, fixed to the surface of the chip substrate.

7. A glycoprotein conjugate, characterized in that, It is formed by conjugating a carrier protein with the Linker structure in the oligosaccharide compound of Streptococcus pneumoniae 10A serum type as described in any one of claims 2-5.

8. The glycoprotein conjugate according to claim 7, characterized in that, The carrier proteins include CRM197, tetanus toxoid, diphtheria toxoid, keyhole hemocyanin, bovine serum albumin, meningococcal outer membrane protein complex, or modifications thereof.

9. A pneumococcal serotype 10A vaccine, characterized in that, It contains the oligosaccharide compound of Streptococcus pneumoniae 10A serotype as described in any one of claims 2-5.

10. A pneumococcal serotype 10A vaccine, characterized in that, It comprises the glycoprotein conjugate of claim 7 or 8.

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