A method of synthesizing alpha-dystroglycan core m3 matrix glycan

Abstract

The application discloses a method for synthesizing alpha-dystroglycan Core M3 matrix glycan, and belongs to the technical field of medicines. The application prepares relevant xylose, glucose and ribitol glycosyl modules by reasonable protection group design. By introducing benzoyl at the 2 position of the xylose group, using the ortho participation effect and an NIS / TMSOTf activation system, the coupling between the xylose module and the ribitol module is completed, and a pseudo disaccharide Xyl beta 1-4Rbo is obtained, with high yield and good beta stereoselectivity. The disaccharide module is coupled by glycosidization at 0 DEG C by using an NIS / AgOTf activation system, so that the by-product ortho ester can be effectively eliminated, and a beta configuration tetrasaccharide and a beta configuration hexasaccharide can be obtained at a high yield, the operation is simple, raw materials are easy to obtain, the method has strong practicability, high yield and low cost, and has important significance for industrial production of the material.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical technology, specifically relating to a method for synthesizing α-muscular dystrophy proteoglycan Core M3 matrix glycan. Background Technology

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

[0003] α-Dystroglycan (α-DG) is an important adhesion molecule of the non-integrin family. O-mannylylation of its surface is a crucial post-translational modification that plays a vital role in the binding of α-DG to extracellular matrix components and participates in the regulation of various physiological functions. Abnormal expression of the O-mannose chain on the α-DG surface can lead to a series of diseases characterized by progressive skeletal muscle weakness, collectively known as α-muscular dystrophy.

[0004] O-mannan on the surface of α-DG can be classified into three core types based on their structure: Core M1 (GlcNAcβ1-2Manα), Core M2 (GlcNAcβ1-2(GlcNAcβ1-6)Manα), and Core M3 (GalNAcβ1-3GlcNAcβ1-4-(phospho-6)Man). Normal glycosylation of Core M3 plays a crucial role in maintaining the normal structure and function of muscles and the brain. However, current biological research on Core M3 glycosylation is still insufficient. Firstly, Core M3 glycosylation is accomplished through the combined action of many glycosyltransferases, making the entire biosynthetic pathway extremely complex. The absence of any gene corresponding to a Core M3 glycosyltransferase can lead to abnormal glycosylation of Core M3. Secondly, the glycan structure of Core M3 is very complex, with different parts performing different biological functions. The ribitol-5-phosphate structure (Rbo5P) is an important part of O-mannan in muscle and can act as a primer for enzymatic glycan elongation, extending the glycan chain under the action of glycosyltransferases TMEM5 and LARGE. Finally, the (-3GlcAβ1-3Xylα1-) repeat sequence in Core M3 is crucial for the binding of α-DG to extracellular matrix components and synaptic molecules.

[0005] Because Core M3 is extremely rare in nature and difficult to extract and purify, there is an urgent need to develop an efficient chemical synthesis method to obtain structurally defined Core M3-related oligosaccharides, laying the material basis for developing potential treatments for muscular dystrophy. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for synthesizing α-muscular dystrophy proteoglycan CoreM3 matrix glycan. This invention utilizes a chemical method to efficiently prepare α-muscular dystrophy proteoglycan CoreM3 matrix glycan related to the pseudodisaccharide Xylβ1-4Rbo, the pseudotetrasaccharide Xylα1-3GlcAβ1-4Xylβ1-4Rbo, and the pseudohexasaccharide.

[0007] Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo, its structure is shown below:

[0008]

[0009] Among them, compound 1 is a pseudohexasaccharide Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo, compound 2 is a pseudotetrasaccharide Xylα1-3GlcAβ1-4Xylβ1-4Rbo, and compound 3 is a pseudodisaccharide Xylβ1-4Rbo.

[0010] In a first aspect, the present invention provides a method for synthesizing α-muscular dystrophy proteoglycan Core M3 matrix glycan, wherein nickel sulfide (NIS) and trimethylsilyl trifluoromethanesulfonate (TMSOTf) or silver trifluoromethanesulfonate (AgOTf) are used as activators, and a glycosylation reaction is carried out between a glycosyl donor and a glycosyl acceptor to obtain a glycosylated product; the glycosylated product is then deprotected to obtain Core M3 matrix glycan.

[0011] The glycosyl donor is compound 4, and the glycosyl acceptor is compound 5.

[0012]

[0013] Alternatively, the glycosyl donor may be compound 6, and the glycosyl acceptor may be compound 7.

[0014]

[0015] Alternatively, the glycosyl donor may be compound 6, and the glycosyl acceptor may be compound 8.

[0016]

[0017] The beneficial effects of this invention are as follows:

[0018] In the method for synthesizing the α-muscular dystrophy proteoglycan Core M3 matrix glycan of the present invention, glycosyl modules of xylose, glucose, and ribitol were prepared through rational protecting group design, namely compounds 4, 5, 6, 7, and 8. By introducing a benzoyl group at the 2-position of the xylose group, utilizing the participation of its neighboring group, and through the NIS / TMSOTf activation system, the coupling between the xylose module and the ribitol module (i.e., compounds 4 and 5) was completed, yielding the pseudodisaccharide Xylβ1-4Rbo with high yield and good β stereoselectivity. Glycosylation coupling of the disaccharide modules (i.e., compounds 6 and 7, and compounds 13 and 7) at 0°C using the NIS / AgOTf activation system effectively eliminated the byproduct orthoester, yielding β-configured tetrasaccharides and hexasaccharides in high yield.

[0019] The method for synthesizing α-muscular dystrophy proteoglycan Core M3 matrix glycan of the present invention is simple to operate, uses readily available raw materials, is highly practical, has a high yield, and is low in cost, which is of great significance for the industrial production of this type of substance. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 Compound 1 NMR 1 H spectrum;

[0022] Figure 2 Compound 2 NMR 1 H spectrum;

[0023] Figure 3 Compound 3 NMR 1 H spectrum;

[0024] Figure 4 Compound 3 NMR 13 C spectrum;

[0025] Figure 5 Compound 6 NMR 1 H spectrum;

[0026] Figure 6 Compound 6 NMR 13 C spectrum;

[0027] Figure 7 Compound 7 NMR 1 H spectrum;

[0028] Figure 8 Compound 7 NMR 13 C spectrum;

[0029] Figure 9 Compound 8 NMR 1 H spectrum;

[0030] Figure 10 Compound 8 NMR 13 C spectrum;

[0031] Figure 11 Compound 9 NMR 1 H spectrum;

[0032] Figure 12 Compound 9 NMR 13 C spectrum;

[0033] Figure 13 Compound 10 NMR 1 H spectrum;

[0034] Figure 14 Compound 10 NMR 13 C spectrum;

[0035] Figure 15 Compound 11 NMR 1 H spectrum;

[0036] Figure 16 Compound 11 NMR 13 C spectrum;

[0037] Figure 17 Compound 12 NMR 1 H spectrum;

[0038] Figure 18 Compound 12 NMR 13 C spectrum;

[0039] Figure 19 Compound 13 NMR 1 H spectrum;

[0040] Figure 20 Compound 13 NMR 13 C spectrum;

[0041] Figure 21 Compound 14 NMR 1 H spectrum;

[0042] Figure 22 Compound 24 NMR 13 C spectrum;

[0043] Figure 23 Compound 15 NMR 1 H spectrum;

[0044] Figure 24 Compound 15 NMR13 C spectrum;

[0045] Figure 25 Compound 16 NMR 1 H spectrum;

[0046] Figure 26 Compound 16 NMR 13 C-spectrum. Detailed Implementation

[0047] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0048] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0049] In this invention, "equivalent" (eq) refers to the ratio of the amounts of substances in an interaction. For example, the meaning of donor (1 equivalent) and acceptor (0.75 equivalent) is that the molar ratio of the donor compound to the acceptor compound in the reaction is 1:0.75.

[0050] In one or more embodiments of the present invention, a method for synthesizing α-muscular dystrophy proteoglycan Core M3 matrix glycan is provided, wherein nickel sulfide (NIS) and trimethylsilyl trifluoromethanesulfonate (TMSOTf) or silver trifluoromethanesulfonate (AgOTf) are used as activators, and a glycosylation reaction is carried out between a glycosyl donor and a glycosyl acceptor to obtain a glycosylated product; the glycosylated product is then deprotected to obtain Core M3 matrix glycan.

[0051] The glycosyl donor is compound 4, and the glycosyl acceptor is compound 5.

[0052]

[0053] Alternatively, the glycosyl donor may be compound 6, and the glycosyl acceptor may be compound 7.

[0054]

[0055] Alternatively, the glycosyl donor may be compound 6, and the glycosyl acceptor may be compound 8.

[0056]

[0057] In one or more embodiments of the present invention, the synthetic route of the pseudobiose Xylβ1-4Rbo associated with Core M3 matrix glycan is as follows: the glycosyl donor is compound 4 and the glycosyl acceptor is compound 5. Using NIS / TMSOTf as an activator, the β-glycosidic bond coupling between compound 4 and compound 5 is completed through a glycosylation reaction, and after deprotection, the pseudobiose Xylβ1-4Rbo of Core M3 matrix glycan is obtained.

[0058] The deprotection operation is as follows: compound 9 is first deprotected by the p-methoxybenzyl (PMB) protecting group, then by the triisopropylsilyl (TIPS) protecting group, and finally by the benzoyl (Bz), benzyl (Bn) and acetyl (Ac) protecting groups to obtain Core M3 matrix polysaccharide pseudobiose Xylβ1-4Rbo, i.e., compound 3.

[0059]

[0060] The glycosylation reaction is carried out at 0°C in a dichloromethane solvent under an inert gas environment, with the molecular sieve acting as a desiccant. Preferably, the molecular sieve is... Molecular sieve.

[0061] The molar ratio of compound 4, compound 5, NIS, and TMSOTf is 1:0.75:2.4:0.24; the molar ratio of compound 4 to solvent volume is 1 mol:5.4 mL; and the mass ratio of the molecular sieve to solvent volume is 0.18 g / mL.

[0062] In one or more embodiments of the present invention, the synthetic route of the pseudotetrasaccharide Xylα1-3GlcAβ1-4Xylβ1-4Rbo associated with Core M3 matrix glycan is as follows: when the glycosyl donor is compound 6 and the glycosyl acceptor is compound 7, the coupling of the β-glycosidic bond between compound 6 and compound 7 is completed through a glycosylation reaction using NIS / AgOTf as an activator, and after deprotection operation, the pseudotetrasaccharide Xylα1-3GlcAβ1-4Xylβ1-4Rbo of Core M3 matrix glycan is obtained.

[0063] The deprotection operation is as follows: compound 11 is first deprotected by the triisopropylsilyl (TIPS) protecting group, and then by the benzoyl (Bz), benzyl (Bn), ester (OMe) and acetyl (Ac) protecting groups to obtain Core M3 matrix polysaccharide pseudotetrasaccharide Xylα1-3GlcAβ1-4Xylβ1-4Rbo, i.e., compound 2.

[0064]

[0065] The glycosylation reaction is carried out at 0°C in a dichloromethane solvent under an inert gas environment, with the molecular sieve acting as a desiccant; preferably, the molecular sieve is... Molecular sieve.

[0066] The molar ratio of compound 6, compound 7, NIS, and AgOTf is 1:0.8:1.1:0.8; the molar ratio of compound 6 to solvent is 1 mol:3 mL; the amount of AgOTf is divided into four equal parts, one-quarter is added before the reaction, and one-quarter is added three times during the reaction, until the reaction is complete.

[0067] In one or more embodiments of the present invention, Core M3 matrix glycan-related pseudohexasaccharides

[0068] The synthetic route of Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo is shown below: Compounds 13 and 7 are coupled via a β-glycosidic bond through a NIS / AgOTf-activated glycosylation reaction to obtain the glycosylated product. After removing the naphthalene (Nap) protecting group from the glycosylated product, compound 8 is obtained. Compound 6 is the glycosyl donor, and compound 8 is the glycosyl acceptor. Using NIS / AgOTf as the activator, the β-glycosidic bond coupling between compounds 6 and 8 is completed through a glycosylation reaction. After deprotection, the Core M3 matrix glycan pseudohexasaccharide Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo is obtained.

[0069] The deprotection operation is as follows: Compound 15 is first deprotected by the triisopropylsilyl (TIPS) protecting group, and then by the benzoyl (Bz), benzyl (Bn), ester (OMe), and acetyl (Ac) protecting groups, to obtain Core M3 matrix glycan pseudohexasaccharide.

[0070] Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo, i.e., compound 1.

[0071]

[0072] The glycosylation reaction is carried out at 0°C in a dichloromethane solvent under an inert gas environment, with the molecular sieve acting as a desiccant; preferably, the molecular sieve is... Molecular sieve.

[0073] The molar ratio of compound 8, compound 6, NIS, and AgOTf is 1:0.8:1.1:0.4; the molar ratio of compound 8 to solvent is 1 mol:4 mL; the amount of AgOTf is divided into two equal portions, half is added before the reaction, and the remaining half is added once during the reaction until the reaction is complete.

[0074] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments. It should be noted that the specific embodiments are explanations of the present invention rather than limitations.

[0075] Example 1

[0076] 1. Chemical synthesis of pseudodisaccharide Xylβ1-4Rbo related to Core M3 matrix glycans

[0077] 1.1 Synthetic route of the pseudobiose Xylβ1-4Rbo related to Core M3 matrix glycans:

[0078]

[0079] 1.2 Specific experimental steps

[0080] Preparation of compound 9

[0081] Compound 4 (0.3 g, 0.54 mmol, 1 eq) and compound 5 (0.25 g, 0.40 mmol, 0.75 eq) were mixed with activated... Molecular sieve (1 g) was placed in a round-bottom flask under argon protection, and 5.4 mL of dichloromethane was added. The mixture was stirred at 0 °C for 10 min, followed by the addition of NIS (0.29 g, 1.29 mmol, 2.4 eq) and TMSOTf (26 μL, 0.13 mmol, 0.24 eq). The mixture was stirred for 0.5 h, and TLC was used to determine the complete reaction of the starting material. Triethylamine was added to quench the reaction, and the molecular sieve was then filtered off. The mixture was diluted with 30 mL of dichloromethane, washed with 1 M sodium thiosulfate solution, dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography to obtain an oily substance (0.33 g, 81%). 1H NMR(600MHz,CDCl3)δ7.92(m,4H,ArH),7.53-7.44(m,2H,ArH),7.37(m,2H,ArH),7.31(m,2H,ArH),7.28-7.23(m,5H,ArH),7.23-7.1(m,3H,ArH),7.18(dd,J=6.8,3.0Hz,2H,ArH),7.13-7.08(m,2H,ArH),6.76-6.67(m,2H,ArH),5.57(t,J=9.0Hz,1H,3a-H),5.35(dd,J=9.3,7.3Hz,1H,2a-H),5.14(d,J=7.3Hz,1H,1a-H),4.63(d,J=11.5Hz,1H,PhCH2),4.56(d,J=11.2Hz,1H,PhCH2),4.55(d,J=11.3Hz,1H,PhCH2,),4.52(d,J=11.8Hz,1H,PhCH2),4.48(d,J=11.1Hz,1H,PhCH2),4.47-4.45(d,1H,J=11.3Hz,PhCH2),4.40(d,J=11.2Hz,1H,1b”-H),4.19(m,1H,2b-H),4.18(m,1H,1b’-H),4.09(d,J=11.9Hz,1H,5a’-H),3.90(m,1H,4b-H),3.81(m,1H,4a-H),3.80(m,1H,5b’-H),3.74(s,3H),3.70-3.62(m,2H,3b-H,5b”-H),3.41(dd,J=11.9,2.3Hz,1H,5a”-H),1.98(s,3H),0.93(s,21H). 13 C NMR(151MHz,CDCl3)δ170.92,165.65,165.33,159.35,138.06,137.96,133.06,132.95,129.79,129.78,129.60,129.57,129.55,129.53,128.28,128.25,128.23,128.22,128.14,127.79,127.61,127.41,113.77,100.75,78.79,77.72,74.53,73.83,72.99,72.51,72.20,71.90,64.75,63.60,63.06,55.17,20.95,17.94,11.71.ESI-HRMS m / z:calcd for C 57 H 70NaO 13 Si[M+Na + ],1013.4478;found,1013.4498

[0082] Preparation of compound 7

[0083] Compound 9 (0.5 g, 0.51 mmol, 1 eq) and DDQ (2,3-dichloro-5,6-dicyano-1,4-benzoquinone) (1.15 g, 5.05 mmol, 10 eq) were placed in a round-bottom flask and dissolved in dichloromethane:phosphate aqueous solution = 5 mL + 0.5 mL. The mixture was stirred at 0 °C for 10 h, and the reaction was confirmed by TLC. The reaction mixture was then diluted with dichloromethane and washed successively with saturated sodium bicarbonate solution (50 mL × 3), saturated sodium chloride solution (50 mL), dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography to obtain an oil (0.31 g, 70%). 1 H NMR (600MHz, CDCl3) δ7.98(m,4H,ArH),7.51(m,2H,ArH),7.36(m,4H,ArH),7.31-7.15(m,10H,ArH),5.48(t,J=8.1Hz,1H,2a-H),5.28(t,J =8.5Hz,1H,3a-H),5.23(m,1H,PhCH2),4.65(d,J=11.4Hz,1H,PhCH2),4.59-4.51(m,2H,PhCH2),4.47(d,J=11.5Hz,1H,PhCH2),4.39(d,J= 11.1Hz,1H,1b'-H),4.25(m,1H,2b-H),4.20(d,J=11.2Hz,1H,1b”-H),4.19(d,J=11.9Hz,1H,5a”-H),4.05(m,1H,4a-H),3.91(m,1H,4b-H) ,3.84(dd,J=10.9,3.8Hz,1H,5b”-H),3.75-3.65(m,2H,5b’-H,3b-H),3.44(m,1H,5a’-H),3.28(s,1H,OH),1.98(s,3H,Me),0.96(s,21H). 13C NMR (151MHz, CDCl3) δ171.01,167.42,165.28,133.58,133.18,129.98,129.76,128.94,128.47,128.36,128.26,128.18,127.83,127.68,127. 49,100.42,78.61,77.67,77.28,77.07,76.87,76.86,76.76,73.02,72 .17,71.17,69.21,65.15,64.92,62.96,20.96,17.98,11.72.ESI-HRMS m / z:calcd forC 49 H 66 NO 12 Si[M+NH4 + ],888.4349;found,888.4353.

[0084] Preparation of compound 3

[0085] Raw material 7 (0.1 g, 0.10 mmol, 1 eq) was placed in an argon-protected round-bottom flask. TBAF·THF (1 mol / L, 0.5 mL, 0.51 mmol, 5 eq) adjusted to pH 7 with HOAc was added. The mixture was stirred at room temperature for 10 h, and TLC showed complete reaction of the raw material. The reaction was quenched with 2 mL of saturated ammonium chloride solution, followed by dilution with dichloromethane, washing with 30 mL of saturated ammonium chloride solution, drying with anhydrous sodium sulfate, filtering, concentrating by rotary evaporation, and purifying by column chromatography. The obtained intermediate was dissolved in 1 mL of methanol, and sodium methoxide was added to adjust the pH to 9-10. The mixture was stirred for 10 h until TLC showed complete reaction. 1% acetic acid was added dropwise until the pH of the reaction system reached 7. The reaction system was concentrated by rotary evaporation, dissolved in 1 mL of methanol, and Pd / C was added. Under H2 protection, the mixture was stirred for 24 h, filtered through diatomaceous earth, and purified by thin-layer chromatography. (20 mg, 61%) 1 H NMR (600MHz, CD3OD) δ4.39 (d, J=7.8Hz, 1H, 1a-H), 3.82 (m, 1H, 2b-H), 3.78 (dd, J= 11.7,2.5Hz,1H,5a”-H),3.73-3.68(m,2H,4b-H,5b’-H),3.65-3.61(m,2H,1b’-H ,5b”-H),3.61-3.57(m,1H,3b-H),3.49-3.40(m,1H,1b”-H),3.38(m,1H,4a-H),3 .27(t,J=9.2Hz,1H,3a-H),3.20(t,J=8.9Hz,1H,2a-H),3.18-3.06(m,1H,5a'-H).13 C NMR (151MHz, CD3OD) δ102.99,80.68,75.50,73.11,71.70,71.42,69.14,65.05,62.52,60.07.ESI-HRMSm / z:calcd for C 10 H 20 NaO9[M+Na + ],307.1000;found,307.1009.

[0086] Example 2

[0087] 2. Chemical synthesis of pseudotetrasaccharides related to Core M3 matrix glycans: Xylα1-3GlcAβ1-4Xylβ1-4Rbo

[0088] 2.1 Preparation of Compound 6:

[0089]

[0090] Preparation of compound 19

[0091] Under argon protection, compounds 17 (50 mg, 0.088 mmol, 1.5 eq), 18 (28 mg, 0.059 mmol, 1 eq), and triphenylphosphine oxide (0.15 g, 0.53 mmol, 9 eq), activated... Molecular sieve (0.15 g / ml) was dissolved in 0.3 mL of dichloromethane and stirred at room temperature for 15 min. Then, TMSI (13 μL, 0.088 mmol, 1.5 eq) was added and stirred at room temperature for 23 h. The reaction was detected by TLC and the reaction was complete. The reaction system was diluted with DCM, washed with 1 M sodium thiosulfate solution, dried, filtered, concentrated by rotary evaporation, and purified by column chromatography to obtain a disaccharide mixture (45 mg, 88%, α:β = 14:1). 11H NMR (600 MHz, CDCl3) δ 8.11 (m, 2H, ArH), 7.55 (m, 1H, ArH), 7.45-7.18 (m, 19H, ArH), 7.17-7.03 (m, 6H, ArH), 6.94 (m, 4H, ArH), 5.45 (s, 1H, PhCH), 5.36 (t, J=9.4 Hz, 1H, 2a-H), 5.34 (d, 1H, J=3.4 Hz, 1b-H), 4.90 (d, J=7.9 Hz, 1H, 1a-H), 4.80 (m, 1H, PhCH2), 4.75 (d, J=10.9 Hz, 1H, PhCH2), 4.51 (d, J=12.4 Hz, 1H, PhCH2), 4.42 (m, 1H, 6a”-H), 4.35 (m, 2H, PhCH2), 4.25 (t, J=8.8 Hz, 1H, 3a-H), 4.14 (d, J=11.8 Hz, 1H, PhCH2), 3.88 (m, 1H, 4a-H), 3.83-3.76 (m, 1H, 6a’-H), 3.71 (m, 1H, 3b-H), 3.62 (m, 1H, 5a-H), 3.31 (m, 1H, 5b’-H), 3.25 (m, 1H, 4b-H), 3.20 (dd, J=9.4, 3.0 Hz, 1H, 2b-H), 3.12 (dd, J=10.4, 2.9 Hz, 1H, 5b”-H), 2.34 (s, 3H). 13 13C NMR (151 MHz, CDCl3) δ 165.03, 139.04, 138.74, 138.52, 138.04, 136.92, 135.67, 133.97, 133.19, 130.08, 130.02, 129.76, 129.47, 128.49, 128.41, 128.29, 128.25, 128.14, 128.05, 127.85, 127.81, 127.45, 127.42, 127.38, 127.35, 127.32, 127.24, 126.38, 102.10, 96.72, 81.79, 80.38, 78.34, 77.64, 76.08, 75.74, 72.51, 71.52, 70.44, 68.75, 60.36, 21.25. ESI-HRMS m / z: calcd for C 53 H 52 NaO 10 S [M+Na + , 903.3173; found, 903.3195

[0092] Preparation of Compound 20

[0093] Under argon protection, compound 19 (0.53 g, 0.60 mmol, 1 eq) and activated... Molecular sieve (0.15 g / ml) was placed in a two-necked flask and dissolved in 6 mL of dichloromethane. BH3·THF (3 mL, 3.01 mmol, 5 eq) and Cu(OTf)2 (0.098 g, 0.27 mmol, 0.45 eq) were added. The mixture was stirred at room temperature for 2 h. TLC analysis confirmed the reaction was complete. Triethylamine and methanol were then added to quench the reaction, and the residue was filtered off. Molecular sieves were used to concentrate the extract by rotary evaporation, followed by column chromatography purification to obtain a disaccharide with a single α-configuration (0.38 g, 72%). 1 HNMR(600MHz, CDCl3)δ8.08-7.96(m,2H,ArH),7.58-7.50(m,1H,ArH),7.41(m,2H, ArH),7.36-7.12(m,22H,ArH),7.08(m,2H,ArH),5.21(t,J=9.4Hz,1H,2a-H),5.10 (d,J=11.3Hz,1H,PhCH2),4.96(d,J=3.5Hz,1H,1b-H),4.82(m,2H,PhCH2),4.71(d ,J=8.0Hz,1H,1a-H),4.66(d,J=12.0Hz,1H,PhCH2),4.56(d,J=11.4Hz,1H,PhCH2) ,4.51(m,2H,PhCH2),4.39(d,J=11.6Hz,1H,PhCH2),4.01(t,J=8.8Hz,1H,3a-H),3 .85(m,1H,3b-H),3.81(m,1H,6a'-H),3.71(t,J=9.3Hz,1H,4a-H),3.66(m,1H,6a' -H),3.54(dd,J=11.7,2.3Hz,1H,5b'-H),3.47(m,1H,5a-H),3.38(m,1H,4b-H),3. 36(m,1H,5b”-H),3.30(dd,J=9.4,3.0Hz,1H,2b-H),2.31(s,3H),1.91(s,1H,OH). 13C NMR (151MHz, CDCl3) δ165.17,138.71,138.28,138.23,132.96,130.40,129.69,129.65,128.96,128.33,128.27,128.01,127.62,127.60,1 27.56,127.51,99.08,86.65,83.50,80.91,79.60,79.35,78.00,75.61,74.91,73.63,72.90,72.13,62.04,60.69,60.37,21.12.ESI-HRMS m / z:calcd for C 53 H 54 NaO 10 S[M+Na + ],905.3330;found,905.3374

[0094] Preparation of compound 6

[0095] Compound 20 (0.3 g, 0.34 mmol, 1 eq) was dissolved in DCM + water = 3 mL + 1.5 mL. Then, TEMPO (0.012 g, 0.068 mmol, 0.2 eq) and BAIB (0.27 g, 0.85 mmol, 2.5 eq) were added. The mixture was stirred at room temperature for 5 h. TLC analysis showed that the reaction was complete. The reaction mixture was diluted with DCM, washed with 1 M sodium thiosulfate solution, dried over anhydrous sodium sulfate, filtered, and concentrated. The concentrated solution was then dissolved in 1 mL of DMF, and MeI (0.21 mL, 3.35 mmol, 10 eq) and anhydrous potassium carbonate (0.93 g, 6.70 mmol, 20 eq) were added. The mixture was stirred at room temperature for 3 h. TLC analysis showed that the reaction was complete. The reaction mixture was diluted with DCM, washed with water, dried, filtered, concentrated by rotary evaporation, and purified by column chromatography. (0.24 g, 81%) 1H NMR (600MHz, CDCl3) δ8.05-7.95(m,2H,ArH),7.60-7.51(m,1H,ArH),7.42(m ,2H,ArH),7.36-7.11(m,24H,ArH),7.09(m,ArH),5.28-5.17(t,J=9.4Hz,1H ,2a-H),5.06(d,J=11.2Hz,1H,PhCH2),4.89(d,J=3.5Hz,1H,1b-H),4.82(m, PhCH2),4.71(d,J=8.0Hz,1H,1a-H),4.65(d,J=12.0Hz,1H,PhCH2),4.51(m, 3H,PhCH2),4.40(t,J=8.8Hz,1H,3b-H),4.30(m,1H,PhCH2),4.03(t,J=8.8H z,1H,3a-H),4.00(t,J=8.9Hz,1H,4a-H),3.95(m,1H,5a-H),3.84(t,J=9.3H z,1H,3b-H),3.68(s,3H,Me),3.51(dd,J=10.9,2.3Hz,1H,5b'-H),3.38(m,1 H,4b-H),3.34(dd,J=9.4,3.0Hz,1H,2b-H),3.27(m,1H,5b”-H),2.32(s,3H). 13 C NMR (151MHz, CDCl3) δ168.27,165.00,138.66,138.31,138.24,138.21,138.08,133. 10,133.00,130.27,129.66,129.64,128.35,128.28,128.27,128.23,128.04,127.9 7,127.63,127.61,127.58,127.55,127.54,127.50,99.20,87.55,83.04,80.86,79. 51,78.86,78.15,77.90,75.67,74.97,73.54,72.92,60.71,52.57,21.17.ESI-HRMS m / z:calcd for C 54 H 54 NaO 11 S[M+Na + ],933.3279;found,933.3314

[0096] 2.2 Synthetic route of the pseudotetrasaccharide Xylα1-3GlcAβ1-4Xylβ1-4Rbo related to Core M3 matrix glycans:

[0097]

[0098] Preparation of compound 11

[0099] Compound 6 (80 mg, 0.09 mmol, 1 eq) and compound 7 (61 mg, 0.07 mmol, 0.8 eq) were mixed with activated... Molecular sieve (0.15 g / mL) was placed in an argon-protected double-necked flask, dissolved in 3 mL of DCM, and stirred at 0 °C for 10 min. NIS (0.022 g, 0.10 mmol, 1.1 eq) and AgOTf (4.5 mg, 0.02 mmol, 0.2 eq) were added, and the mixture was stirred at 0 °C for 22 h. AgOTf (4.5 mg, 0.02 mmol, 0.2 eq) was added three times during the process until TLC showed complete reaction of the starting material. The reaction was quenched with triethylamine, the molecular sieve was filtered, diluted with DCM, washed with 1 M sodium thiosulfate solution, dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography (92 mg, 79%). 1 H NMR (600MHz, CDCl3) δ8.03-7.98(m,2H),7.95-7.88(m,4H),7.60-7.54(m,1H),7.50-7.40(m,4H),7.37-7 .12(m,30H),7.07(m,2H),5.55(t,J=8.7Hz,1H),5.30(dd,J=9.1,7.2Hz,1H),5.21(t,J=8.0Hz,1H),5.03( d,J=7.2Hz,1H),4.94(d,J=11.1Hz,1H),4.88(dd,J=10.5,2.8Hz,1H),4.86-4.77(m,2H),4.67-4.63(m,2 H),4.57(d,J=11.5Hz,1H),4.54-4.47(m,4H),4.46-4.40(m,2H),4.35(m,2H),1.95(s,3H),0.88(s,21H). 13C NMR (151MHz, CDCl3) δ170.93,167.76,165.23,165.16,164.60,138.67,138.30,138.23,138.00,137.97,137.93,133.15,132.96,132. 83,129.95,129.84,129.74,129.71,129.48,129.47,128.52,128.27,128.23,128.20,128.17,128.13,128.05,127.86,127.76,127.60 ,127.58,127.55,127.53,127.51,127.45,127.41,101.66,100.43,99.00,81.50,80.84,79.49,78.80,78.53,77.92,77.60,76.76,76 .64,75.64,74.74,74.51,73.50,72.97,72.86,72.72,72.16,71.81,64.42,63.00,60.69,52.25,20.95,17.96,17.91,11.65.ESI-HRMS m / z:calcd for C 96 H 108 NaO 23 Si[M+Na + ]:1679.6943; found:1679.6989.

[0100] Preparation of compound 12

[0101] Compound 11 (20 mg, 0.01 mmol, 1 eq) was placed in an argon-protected round-bottom flask, and TBAF·THF (1 mol / L, 60 μL, 0.06 mmol, 5 eq) adjusted to pH 7 with HOAc was added. The mixture was stirred at room temperature for 10 h, and TLC showed that the reaction proceeded completely. The reaction was quenched with 2 mL of saturated ammonium chloride solution, followed by dilution with DCM, washing with 30 mL of saturated ammonium chloride solution, drying over anhydrous sodium sulfate, filtering, concentrating by rotary evaporation, and purifying by column chromatography. (15 mg, 83) 1H NMR(600MHz,CDCl3)δ8.02-7.89(m,6H),7.57(t,J=7.3Hz,1H),7.53-7.41(m,5H),7.40-7.15(m,35H),7.08(m,2H),5.56(t,J=9.0Hz,1H),5.28(dd,J=9.2,7.4Hz,1H),5.22(t,J=7.6Hz,1H),4.96(d,J=11.1Hz,1H),4.90(d,J=3.5Hz,1H),4.85-4.79(m,2H),4.76(d,J=7.2Hz,1H),4.70-4.65(m,2H),4.64(d,J=11.2Hz,1H),4.61(d,J=11.6Hz,1H),4.57(d,J=11.1Hz,1H),4.53(d,J=11.7Hz,1H),4.49(m,2H),4.43(m,2H),4.36(d,J=11.1Hz,1H),4.16(dd,J=12.0,5.0Hz,1H),4.09(dd,J=9.1,5.1Hz,1H),3.96-3.75(m,9H),3.59-3.50(m,3H),3.39(s,3H),3.33(m,2H),3.27(dd,J=12.2,9.7Hz,1H),1.96(s,3H). 13 C NMR(151MHz,CDCl3)δ170.78,167.85,165.40,165.26,164.58,138.68,138.31,138.25,137.98,137.74,137.68,133.33,133.20,132.88,129.80,129.74,129.50,128.54,128.49,128.38,128.34,128.28,128.25,128.19,128.07,128.05,127.87,127.83,127.60,127.58,127.52,100.58,99.04,81.61,80.85,79.52,79.03,78.82,78.54,77.93,76.54,75.92,75.65,74.77,74.54,74.10,73.54,72.98,72.87,72.63,72.16,72.11,63.15,62.70,61.56,60.70,52.28,20.93.ESI-HRMS m / z:calcd for C 87 H 88 NaO 23 [M+Na+ ],1523.5609; found,1523.5672.

[0102] Preparation of compound 2

[0103] Compound 12 (0.2 g, 0.13 mmol, 1 eq) was dissolved in 7 mL THF + 0.5 mL H₂O, and 1 mL of 1.25 M LiOH aqueous solution (1.3 mmol, 10 eq) was added. The mixture was stirred at 0 °C for 2.5 h, followed by rotary evaporation. The solution was dissolved in 10 mL methanol, and 0.5 mL of 0.5 M NaOH aqueous solution was added. The mixture was stirred at 0 °C, then brought to room temperature and stirred for another 12 h. TLC showed that the reaction was complete. The reaction was quenched dropwise with 1% acetic acid. The reaction mixture was concentrated by rotary evaporation, dissolved in 5 mL methanol + 5 mL water, and Pd / C was added. The mixture was stirred under H₂ protection for 24 h, filtered through diatomaceous earth, and purified by thin-layer chromatography. (63 mg, 80%)

[0104] Example 3

[0105] 3. Chemical synthesis of pseudohexasaccharides related to Core M3 matrix glycans: Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo

[0106] 3.1 Synthetic route of compound 13:

[0107]

[0108] Preparation of compound 22

[0109] Under argon protection, compound 21 (50 mg, 0.081 mmol, 1.5 eq), compound 18 (26 mg, 0.054 mmol, 1 eq), and triphenylphosphine oxide (0.14 g, 0.49 mmol, 9 eq), activated... Molecular sieve (0.15 g / mL) was dissolved in 0.3 mL of dichloromethane and stirred at room temperature for 15 min. Then, TMSI (12 μL, 0.081 mmol, 1.5 eq) was added, and the mixture was stirred at room temperature for 23 h. The reaction was monitored by TLC until complete. The molecular sieve was then filtered off, and the reaction mixture was diluted with dichloromethane, washed with 1 M sodium thiosulfate solution, dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography to obtain a mixture of two disaccharide configurations (43 mg, 84% α:β = 10:1). ESI-HRMS m / z:calcd for C 57 H 54 NaO 10 S[M+Na + ],953.3330;found,953.3323

[0110] Preparation of compound 23

[0111] Under argon protection, compound 22 (0.3 g, 0.32 mmol, 1 eq) and activated... Molecular sieve (0.15 g / mL) was dissolved in 3 mL of LCM in a two-necked flask. BH3·THF (1 mol / L, 1.6 mL, 1.61 mmol, 5 eq) and Cu(OTf)2 (0.052 g, 0.14 mmol, 0.45 eq) were added. The mixture was stirred at room temperature for 2 h. TLC analysis confirmed the reaction was complete. Triethylamine and methanol were then added to quench the reaction. The molecular sieve was filtered off, and the mixture was concentrated by rotary evaporation and purified by column chromatography to obtain a single-configuration disaccharide (0.24 g, 80%). 1 H NMR (600MHz, CDCl3) δ8.07-8.01(m,2H,ArH),7.80-7.76(m,1H,ArH),7.75-7.66(m,3 H,ArH),7.57(m,1H,ArH),7.43(m,5H,ArH),7.40-7.15(m,17H,ArH),7.10(d,J=7.7H z, 2H, ArH), 5.24 (t, J = 9.4Hz, 1H, 2a-H), 5.12 (d, J = 11.5Hz, 1H, PhCH2), 4.99 (d, J = 3. 6Hz,1H,1b-H),5.04-4.96(m,2H,PhCH2),4.71(d,J=10.2Hz,1H,1a-H),4.77-4.68(m, 1H,PhCH2),4.60-4.52(m,3H,PhCH2),4.44(d,J=11.5Hz,1H,PhCH2),4.04(t,J=8.8H z,1H,3a-H),3.93(dd,J=9.4,7.2Hz,1H,3b-H),3.88(m,1H,6a'-H),3.74(dd,J=9.8, 7.9Hz,1H,4a-H),3.68(m,1H,6a”-H),3.57(m,1H,5b’-H),3.50(m,1H,5a-H),3.47-3 .41(m,1H,4b-H),3.38(dd,J=9.4,3.0Hz,1H,2b-H),3.30(m,1H,5b”-H),2.33(s,3H). 13C NMR (151MHz, CDCl3) δ165.22,138.28,138.22,138.16,136.20,133.27,133.00,132.96,132. 91,130.38,129.73,129.68,128.96,128.38,128.36,128.32,128.31,128.01,127.96,127.9 0,127.66,127.65,127.63,127.62,127.60,126.65,126.22,125.89,125.72,99.04,86.69,8 3.43,80.86,79.65,79.37,78.00,75.66,74.92,73.66,72.92,62.04,60.71,21.16.ESI-HRMS m / z:calcd forC 57 H 56 NaO 10 S[M+Na + ],955.3486;found,955.3474

[0112] Preparation of compound 13

[0113] Compound 23 (0.4 g, 0.43 mmol, 1 eq) was dissolved in dichloromethane + water = 2 mL + 1 mL. Then, TEMPO (0.015 g, 0.086 mmol, 0.2 eq) and BAIB (0.35 g, 1.07 mmol, 2.5 eq) were added, and the mixture was stirred at room temperature for 5 h. TLC analysis showed that the reaction was complete. The reaction mixture was diluted with dichloromethane, washed with 1 M sodium thiosulfate solution, dried over anhydrous sodium sulfate, filtered, and concentrated. The concentrated solution was then dissolved in 1 mL of DMF, and MeI (0.26 mL, 4.23 mmol, 10 eq) and anhydrous potassium carbonate (1.16 g, 8.46 mmol, 20 eq) were added. The mixture was stirred at room temperature for 3 h, and TLC analysis showed that the reaction was complete. The reaction mixture was diluted with DCM, washed with water, dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography (0.71 g, 86%). 1H NMR(600MHz,CDCl3)δ8.07-7.97(m,2H,ArH),7.82-7.76(m,1H,ArH),7.75-7.66(m,3H,ArH),7.61-7.54(m,1H,ArH),7.47-7.40(m,5H,ArH),7.38-7.33(m,2H,ArH),7.31-7.13(m,14H,ArH),7.10(m,2H,ArH),5.32-5.22(t,1H,J=9.2Hz,2a-H),5.09(d,J=11.2Hz,1H,PhCH2),5.04-4.96(m,2H,PhCH2),4.95(d,J=3.5Hz,1H,1b-H),4.74(d,J=8.0Hz,1H,1a-H),4.70(d,J=12.1Hz,1H,PhCH2),4.58-4.50(m,3H,PhCH2),4.44(d,J=11.6Hz,1H,PhCH2),4.05(t,J=8.8Hz,1H,3a-H),4.03(dd,J=9.8,7.9Hz,1H,4a-H),3.98(m,1H,5a-H),3.94-3.89(m,1H,3b-H),3.70(s,3H,Me),3.55(t,J=10.9Hz,1H,5b’-H),3.43(m,1H,4b-H),3.40-3.32(m,2H,2b-H,5b”-H),2.34(s,3H). 13 C NMR(151MHz,CDCl3)δ168.29,165.03,138.34,138.27,138.22,138.08,136.20,133.27,133.14,133.03,132.91,130.29,129.69,129.67,128.76,128.37,128.33,128.31,128.26,127.97,127.91,127.66,127.62,127.60,127.57,127.53,126.65,126.21,125.90,125.72,99.18,87.57,82.99,80.87,79.58,78.89,78.17,77.93,75.71,74.98,73.57,72.92,71.59,60.74,52.59,21.19.ESI-HRMS m / z:calcd forC 58 H 56 NaO 11 S[M+Na +],983.3436;found,983.3450

[0114] 3.2 Synthetic route of the pseudohexasaccharide Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo related to Core M3 matrix glycans:

[0115]

[0116] Preparation of compound 14

[0117] Compound 13 (0.2 g, 0.21 mmol, 1 eq) and compound 7 (0.15 g, 0.17 mmol, 0.8 eq) were mixed with activated... Molecular sieve (0.15 g / mL) was placed in an argon-protected double-necked flask, dissolved in 7 mL of dichloromethane, and stirred at 0 °C for 10 min. NIS (0.052 g, 0.23 mmol, 1.1 eq) and AgOTf (11 mg, 0.042 mmol, 0.2 eq) were added, and the mixture was stirred at 0 °C for 22 h, with AgOTf (11 mg, 0.042 mmol, 0.2 eq) added once during the process until TLC showed complete reaction of the starting material. The reaction was quenched with triethylamine, the molecular sieve was filtered, diluted with dichloromethane, washed with 1 M sodium thiosulfate solution, dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography (0.21 g, 73%). 1H NMR(600MHz,CDCl3)δ8.01(m,2H),7.95-7.87(m,4H),7.78(dd,J=8.4,4.6Hz,1H),7.73-7.65(m,3H),7.57(m,1H),7.50-7.38(m,8H),7.38-7.13(m,28H),7.10-7.04(m,2H),5.63-5.51(m,1H),5.31(m,1H),5.23(t,J=8.0Hz,1H),5.07-5.00(m,1H),5.01-4.89(m,4H),4.71-4.63(m,2H),4.59-4.50(m,6H),4.46-4.41(m,2H),4.36(m,2H),4.17(dd,J=12.0,4.9Hz,1H),4.12-4.02(m,2H),3.96-3.83(m,7H),3.75(dd,J=10.8,4.3Hz,1H),3.64(dd,J=7.2,3.0Hz,1H),3.60(dd,J=10.7,6.9Hz,1H),3.54(t,J=10.8Hz,1H),3.42(m,1H),3.39-3.34(m,5H),3.27(dd,J=12.1,9.6Hz,1H),1.96(m,3H),0.89(s,21H). 13 C NMR(151MHz,CDCl3)δ170.93,167.77,165.24,165.18,164.62,138.24,137.96,129.84,129.75,129.73,129.50,128.52,128.30,128.28,128.23,128.20,128.18,128.14,127.94,127.90,127.83,127.77,127.60,127.58,127.56,127.50,127.45,127.41,126.64,126.21,125.87,101.63,100.43,98.96,81.42,80.84,79.56,78.80,78.56,77.93,77.64,76.61,75.66,74.71,74.52,73.52,73.08,72.99,72.86,72.72,72.18,71.82,64.42,63.03,60.70,52.25,20.95,17.91,11.66.ESI-HRMS m / z:calcd for C 100 H 110 NaO 23Si[M+Na + ],1730.7133; found,1730.7174.

[0118] Preparation of compound 8

[0119] Compound 14 (0.5 g, 0.29 mmol, 1 eq) was dissolved in 3 mL of dichloromethane and 0.3 mL of phosphate aqueous solution (pH = 7.4). After stirring at 0 °C for 10 min, DDQ (0.67 g, 0.29 mmol, 10 eq) was added, and the mixture was stirred for 4 h until TLC showed complete reaction of the starting material. The solution was diluted with 30 mL of dichloromethane and extracted with 30 mL of NaHCO3 aqueous solution. After drying with anhydrous sodium sulfate, the solution was filtered, concentrated by rotary evaporation, and purified by column chromatography. (0.32 g, 71%) 1 H NMR (600MHz, CDCl3) δ8.00-7.97(m,2H),7.90(m,4H),7.59-7.53(m,1H),7.49-7. 41(m,4H),7.35-7.12(m,28H),7.11-7.06(m,2H),5.53(t,J=8.7Hz,1H),5.28(dd, J=9.0,7.1Hz,1H),5.18(t,J=7.9Hz,1H),5.01(d,J=7.1Hz,1H),4.94-4.85(m,2H ),4.63(d,J=7.4Hz,1H),4.60(d,J=12.1Hz,1H),4.56(d,J=11.5Hz,1H),4.50(m,3 H),4.47(d,J=11.6Hz,1H),4.44-4.39(m,2H),4.35(m,2H),4.15(dd,J=11.9,5.1 Hz,1H),4.09-4.01(m,2H),3.96-3.82(m,7H),3.74(dd,J=10.8,4.4Hz,1H),3.63( dd,J=7.1,3.2Hz,1H),3.59(dd,J=10.8,6.9Hz,1H),3.48(t,J=11.1Hz,1H),3.36- 3.30(m,4H),3.29-3.18(m,3H),2.43(d,J=2.0Hz,1H),1.94(s,3H),0.87(s,21H). 13C NMR (151MHz, CDCl3) δ170.91,165.17,138.11,138.05,138.03,137.98,137.93,129.96,129.84,129.75,129. 49,128.53,128.42,128.37,128.22,128.19,128.13,128.03,127.81,127.76,127.72,127.66,127.58,127.50 ,127.48,127.40,101.58,100.41,98.32,81.35,79.11,78.80,78.53,77.70,77.39,76.57,74.66,74.52,73.12,73.03,73.00,72.70,72.51,72.41,72.18,71.83,64.41,63.05,62.98,60.12,52.23,20.92,17.89,11.66.

[0120] ESI-HRMS m / z:calcd for C 89 H 106 NO 23 Si[M+NH4 + ],1584.6919; found,1584.6953.

[0121] Preparation of compound 15

[0122] Compound 8 (0.1 g, 0.11 mmol, 1 eq) and compound 6 (0.14 g, 0.09 mmol, 0.8 eq) were mixed with activated... Molecular sieve (0.15 g / mL) was placed in an argon-protected double-necked flask, dissolved in 4 mL of dichloromethane, and stirred at 0 °C for 10 min. NIS (0.027 g, 0.12 mmol, 1.1 eq) and AgOTf (6 mg, 0.022 mmol, 0.2 eq) were added, and the mixture was stirred at 0 °C for 22 h, with AgOTf (6 mg, 0.022 mmol, 0.2 eq) added once during the process until TLC showed complete reaction of the starting material. The reaction was quenched with triethylamine, the molecular sieve was filtered, diluted with dichloromethane, washed with 1 M sodium thiosulfate solution, dried over anhydrous sodium sulfate, filtered, concentrated by rotary evaporation, and purified by column chromatography (0.16 g, 77%). 1H NMR(600MHz,CDCl3)δ7.91-7.83(m,8H),7.54-7.48(m,1H),7.48-7.42(m,2H),7.42-7.38(m,1H),7.36(m,2H),7.33-7.08(m,45H),7.04(m,2H),7.01-6.96(m,2H),5.50(t,J=8.7Hz,1H),5.31(t,J=8.2Hz,1H),5.26(dd,J=9.1,7.1Hz,1H),5.08(d,J=7.7Hz,1H),5.06-5.03(m,1H),5.01-4.97(m,2H),4.91(d,J=3.5Hz,1H),4.79(m,2H),4.75(d,J=11.6Hz,1H),4.65(m,2H),4.57-4.52(m,2H),4.52-4.44(m,6H),4.41(m,2H),4.38-4.32(m,3H),4.27(d,J=11.7Hz,1H),4.14(dd,J=11.9,5.0Hz,1H),4.10-4.02(m,4H),3.98(m,1H),3.90(m,2H),3.87-3.79(m,3H),3.79-3.75(m,1H),3.73(dd,J=10.8,4.4Hz,1H),3.70-3.65(m,2H),3.62(dd,J=7.1,3.2Hz,1H),3.60-3.54(m,4H),3.52(d,J=10.9Hz,1H),3.42(t,J=11.1Hz,1H),3.36(m,1H),3.33-3.25(m,6H),3.24-3.20(m,1H),3.17(m,1H),3.04(dd,J=9.7,3.5Hz,1H),1.93(s,3H),0.86(s,21H). 13C NMR (151MHz, CDCl3) δ170.90,168.61,167.69,165.23,165.16,164.84,164.50,138.73 ,138.68,138.32,138.29,138.21,138.08,138.04,137.97,133.01,132.95,132.87,132 .79,130.29,129.98,129.83,129.73,129.60,129.49,129.34,128.42,128.28,128.26,128.21,128.18,128.16,128.13,128.03,128.01,127.94,127.80,127.75,127.64,127. 58, 127.55, 127.49, 127.45, 127.40, 127.36, 101.56, 101.05, 100.41, 98.81, 98.46, 81.84, 81.54, 80.90, 79.81, 79.58, 79.32, 78.79, 78.59, 77.94, 77.84, 77.69, 75.84, 75.6 2,74.68,74.58,74.44,74.31,73.52,73.47,73.39,73.31,73.13,72.98,72.80,72.68, 72.17,71.80,64.39,63.05,62.96,60.67,52.35,52.17,20.92,17.88,11.65.ESI-HRMS m / z:calcd for C 136 H 148 NaO 34 Si[M+Na + ],2376.9547; found,2376.9568.

[0123] Preparation of compound 16

[0124] Compound 15 (30 mg, 0.01 mmol, 1 eq) was placed in an argon-protected round-bottom flask, and TBAF·THF (1 mol / L, 64 μL, 0.063 mmol, 5 eq) adjusted to pH 7 with HOAc was added. The mixture was stirred at room temperature for 10 h, and TLC showed that the reaction proceeded completely. The reaction was quenched with 2 mL of saturated ammonium chloride solution, followed by dilution with dichloromethane, washing with 30 mL of saturated ammonium chloride solution, drying over anhydrous sodium sulfate, filtering, concentrating by rotary evaporation, and purifying by column chromatography (26 mg, 93%). 1H NMR(600MHz,CDCl3)δ7.94-7.81(m,9H),7.53-7.08(m,61H),7.07-7.01(m,2H),7.01-6.94(m,2H),5.51(m,1H),5.35-5.28(m,1H),5.24(m,1H),5.09(dd,J=7.7,1.6Hz,1H),5.07-5.02(m,1H),5.00(d,J=11.1Hz,1H),4.91(d,J=3.5Hz,1H),4.79(m,2H),4.77-4.70(m,2H),4.66(m,2H),4.62-4.52(m,4H),4.48(m,5H),4.43-4.38(m,2H),4.36(m,2H),4.28(d,J=11.6Hz,1H),4.14(dd,J=11.9,4.8Hz,1H),4.11-3.98(m,4H),3.90(m,3H),3.85-3.79(m,3H),3.79-3.67(m,4H),3.57(s,3H),3.56-3.49(m,3H),3.42(t,J=11.2Hz,1H),3.36(m,1H),3.31(s,4H),3.22(dd,J=12.0,9.8Hz,1H),3.17(dd,J=11.5,6.0Hz,1H),3.05(m,1H),1.94(s,3H). 13CNMR(151MHz, CDCl3)δ170.75,168.61,167.75,165.39,165.24,164.84,164.47,138.73, 138.68,138.32,138.28,138.20,138.08,138.02,137.75,137.69,133.32,132.87,132.83 ,130.29,129.92,129.78,129.73,129.66,129.60,129.36,129.12,128.47,128.43,128.36,128.32,128.28,128.26,128.22,128.18,128.04,127.94,127.91,127.80,127.77,127 .63,127.58,127.55,127.50,127.46,127.43,127.37,101.09,101.05,100.56,98.81,98.48,81.81,81.54,80.89,79.77,79.58,79.32,79.03,78.86,78.60,77.93,77.89,76.57, 75.94,75.85,75.62,74.70,74.58,74.45,74.33,74.09,73.52,73.48,73.42,73.28,73.0 2,72.80,72.60,72.17,72.09,63.14,62.71,61.53,60.66,60.54,52.35,52.20.ESI-HRMS m / z:calcd for C 127 H 128 NaO 34 [M+Na + ],2220.8213; found,2220.8234.

[0125] Preparation of Compound 1

[0126] Compound 16 (0.2 g, 0.091 mmol, 1 eq) was dissolved in 14 mL THF + 1 mL H₂O, and 0.73 mL of 1.25 M LiOH aqueous solution (0.91 mmol, 10 eq) was added. The mixture was stirred at 0 °C for 2.5 h, followed by rotary evaporation. The solution was dissolved in 10 mL methanol, and 0.5 mL of 0.5 M NaOH aqueous solution was added. The mixture was stirred at 0 °C and then brought to room temperature, with stirring continuing for 12 h. TLC showed that the reaction was complete. 1% acetic acid was added dropwise until the pH of the reaction system reached 7. The reaction system was concentrated by rotary evaporation, dissolved in 5 mL methanol + 5 mL water, and Pd / C was added. The mixture was stirred for 24 h under H₂ protection, filtered through diatomaceous earth, and purified by gel permeation chromatography, yielding 85%.

[0127] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of synthesizing the α-dystroglycan Core M3 matrix glycan glycan-associated pseudohexaose Xylαl-3GlcAβl-3Xylαl-3GlcAβl-4Xylβl-4Rbo, characterized in that, Compounds 13 and 7 were coupled via β-glycosidic bonds through a NIS / AgOTf-activated glycosylation reaction to obtain a glycosylated product. After removing the naphthalene Nap protecting group from the glycosylated product, compound 8 was obtained. Compound 6 was used as the glycosyl donor and compound 8 as the glycosyl acceptor. Using NIS / AgOTf as the activator, the β-glycosidic bonds between compounds 6 and 8 were coupled via a glycosylation reaction. After deprotection, the Core M3 matrix glycan pseudohexasaccharide Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo was obtained. The deprotection operation is as follows: Compound 15 is first deprotected by the triisopropylsilyl TIPS protecting group, and then by the benzoyl Bz, benzyl Bn, ester OMe and acetyl Ac protecting groups to obtain Core M3 matrix polysaccharide pseudohexasaccharide Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo, i.e., compound 1; The glycosylation reaction is carried out at low temperature in a solvent, in an inert gas environment, with molecular sieves used as a desiccant; the low temperature is 0°C; the solvent is dichloromethane. The molar ratio of compound 8, compound 6, NIS, and AgOTf is 1:0.8:1.1:0.4; the molar ratio of compound 8 to solvent is 1 mol:4 mL; the amount of AgOTf is divided into two equal portions, half is added before the reaction, and the remaining half is added once during the reaction until the reaction is complete. The above reaction process is as follows: 。 2. The method for synthesizing the pseudohexasaccharide Xylα1-3GlcAβ1-3Xylα1-3GlcAβ1-4Xylβ1-4Rbo associated with the α-muscular dystrophy proteoglycan Core M3 matrix glycan as described in claim 1, characterized in that, The molecular sieve is a 4Å molecular sieve.

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