116 results on '"Xin, Shan"'
Search Results
2. Protection-Free Site-Directed Peptide or Protein S -Glycosylation and Its Application in the Glycosylation of Glucagon-like Peptide 1
- Author
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Yuankun Dao, Gefei Li, Shin Ichiro Shoda, Juan Mo, Xin-Shan Ye, and Suwei Dong
- Subjects
chemistry.chemical_classification ,animal structures ,Glycosylation ,biology ,Disulfide bond ,Peptide ,macromolecular substances ,General Chemistry ,Glucagon-like peptide-1 ,Protein S ,carbohydrates (lipids) ,chemistry.chemical_compound ,Biochemistry ,chemistry ,biology.protein ,lipids (amino acids, peptides, and proteins) - Abstract
The development of a facile cysteine-directed S-glycosylation strategy would facilitate the intensive investigation of the effect of glycosylation on protein translational modification. Herein, we ...
- Published
- 2022
3. Donor <scp>Preactivation‐Based</scp> Glycosylation: An Efficient Strategy for Glycan Synthesis
- Author
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Xianjin Qin and Xin-Shan Ye
- Subjects
Glycan ,chemistry.chemical_compound ,Glycosylation ,biology ,chemistry ,Stereochemistry ,biology.protein ,General Chemistry ,Chemoselectivity ,Solvent effects ,Oligosaccharide synthesis - Published
- 2021
4. Synthesis and immunological evaluation of N-acyl modified Globo H derivatives as anticancer vaccine candidates
- Author
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Chengcheng Song, Xiu-Jing Zheng, Xin-Shan Ye, and Canjia Zhai
- Subjects
Synthetic vaccine ,Glycosylation ,Glycoconjugate ,medicine.medical_treatment ,Pharmaceutical Science ,H antigen ,010402 general chemistry ,01 natural sciences ,Biochemistry ,chemistry.chemical_compound ,Immune system ,Drug Discovery ,medicine ,Pharmacology ,chemistry.chemical_classification ,biology ,010405 organic chemistry ,Immunogenicity ,Organic Chemistry ,0104 chemical sciences ,chemistry ,Cancer research ,biology.protein ,Molecular Medicine ,Antibody ,Adjuvant - Abstract
Globo H is a tumor-associated carbohydrate antigen (TACA), which serves as a valuable target for antitumor vaccine or cancer immunotherapies. However, most TACAs are T-cell-independent, and they cannot induce powerful immune response due to their poor immunogenicity. To address this problem, herein, several Globo H analogues with modification on the N-acyl group were prepared through a preactivation-based glycosylation strategy from the non-reducing end to the reducing end. These modified Globo H derivatives were then conjugated with carrier protein CRM197 to form glycoconjugates as anticancer vaccine candidates, which were used in combination with adjuvant glycolipid C34 for immunological studies. The immunological effects of these synthetic vaccine candidates were evaluated on Balb/c mice. The results showed that the fluorine-modified N-acyl Globo H conjugates can induce higher titers of IgG antibodies that can recognize the naturally occurring Globo H antigen on the surface of cancer cells and can eliminate cancer cells in the presence of a complement, indicating the potential of these synthetic glycoconjugates as anticancer vaccine candidates.
- Published
- 2021
5. Visible-light-promoted 3,5-dimethoxyphenyl glycoside activation and glycosylation
- Author
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Qin Li, De-Cai Xiong, Yafei Cao, Xin-Shan Ye, Runze Mao, Da-Ke Liu, Feng Xia, Jianhui Liu, Min-Min Zhou, and You Zou
- Subjects
chemistry.chemical_classification ,animal structures ,Glycosylation ,Stereochemistry ,Metals and Alloys ,Glycoside ,macromolecular substances ,General Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Nucleobase ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Visible spectrum - Abstract
A new glycosylation method promoted by visible light with 3,5-dimethoxyphenyl glycoside as the donor was developed. This protocol delivers both O-glycosides and N-glycosides in moderate to excellent yields using a wide range of O-nucleophiles and nucleobases as the glycosyl acceptors.
- Published
- 2021
6. Recent advances in glycan synthesis
- Author
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Xin-Shan Ye and Bo-Han Li
- Subjects
0301 basic medicine ,Glycan ,Glycosylation ,biology ,Chemistry ,Stereoisomerism ,Chemistry Techniques, Synthetic ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Chemical synthesis ,Enzymes ,0104 chemical sciences ,Analytical Chemistry ,carbohydrates (lipids) ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Polysaccharides ,biology.protein - Abstract
Carbohydrates play important roles in life science, but their synthesis is always hampered by their complicated chemical structures. Scientists have never stopped trying to solve the problem of glycan synthesis from various aspects. Here a brief overview of recent progress in glycan synthesis, including chemical approaches, chemoenzymatic approaches, and automated synthesis, will be discussed, focusing on the efficiency of new glycosylation methods, the stereoselectivity of coupled products, and their applications in the assembly of complex glycan chains.
- Published
- 2020
7. Iterative Synthesis of 2‐Deoxyoligosaccharides Enabled by Stereoselective Visible‐Light‐Promoted Glycosylation
- Author
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Kai‐Meng Liu, Peng‐Yu Wang, Zhen‐Yan Guo, De‐Cai Xiong, Xian‐Jin Qin, Miao Liu, Meng Liu, Wan‐Ying Xue, and Xin‐Shan Ye
- Subjects
Glycosylation ,Light ,Alcohols ,General Chemistry ,General Medicine ,Alkenes ,Catalysis - Abstract
The photoinitiated intramolecular hydroetherification of alkenols has been used to form C-O bonds, but the intermolecular hydroetherification of alkenes with alcohols remains an unsolved challenge. We herein report the visible-light-promoted 2-deoxyglycosylation of alcohols with glycals. The glycosylation reaction was completed within 2 min in a high quantum yield (ϕ=28.6). This method was suitable for a wide array of substrates and displayed good reaction yields and excellent stereoselectivity. The value of this protocol was further demonstrated by the iterative synthesis of 2-deoxyglycans with α-2-deoxyglycosidic linkages up to a 20-mer in length and digoxin with β-2-deoxyglycosidic linkages. Mechanistic studies indicated that this reaction involved a glycosyl radical cation intermediate and a photoinitiated chain process.
- Published
- 2022
8. Engineering a bacterial sialyltransferase for di-sialylation of a therapeutic antibody
- Author
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Yue Wang, Xin-Shan Ye, Liangren Zhang, Mingqun Wang, Kaimeng Liu, Zhenming Liu, and Xiaodong Dou
- Subjects
chemistry.chemical_classification ,Glycosylation ,biology ,Photobacterium ,Sialyltransferase ,Organic Chemistry ,Mutant ,Mutagenesis (molecular biology technique) ,Protein Engineering ,Biochemistry ,Antibodies ,Sialyltransferases ,carbohydrates (lipids) ,chemistry.chemical_compound ,Enzyme ,chemistry ,Sialic Acids ,biology.protein ,Physical and Theoretical Chemistry ,Antibody ,Bioorthogonal chemistry ,Glycoprotein ,beta-D-Galactoside alpha 2-6-Sialyltransferase - Abstract
Terminal α-2,6-sialylation of N-glycans is a humanized glycosylation that affects the properties and efficacy of therapeutic glycoproteins. Fc di-sialylation (a biantennary N-glycan with two α-2,6-linked sialic acids) of IgG antibodies imparts them with enhanced anti-inflammatory activity and other roles. However, the microheterogeneity of N-glycoforms presents a challenge for therapeutic development. Therefore, controlled sialylation has drawn considerable attention, but direct access to well-defined di-sialylated antibodies remains limited. Herein, a one-pot three-enzyme protocol was developed by engineering a bacterial sialyltransferase to facilitate the modification of therapeutic antibodies with N-acetylneuraminic acid or its derivatives towards optimized glycosylation. To overcome the low proficiency of bacterial sialyltransferase in antibody remodeling, the Photobacterium sp. JT-ISH-224 α-2,6-sialyltransferase (Psp2,6ST) was genetically engineered by terminal truncation and site-directed mutagenesis based on its protein crystal structure. With the optimized reaction conditions and using activity-based screening of various Psp2,6ST variants, a truncated mutant Psp2,6ST (111-511)-His6 A235M/A366G was shown to effectively improve the catalytic efficiency of antibody di-sialylation. Herceptin and the donor substrate promiscuity allow the introduction of bioorthogonal modifications of N-acetylneuraminic acid into antibodies for site-specific conjugation. 2-AB hydrophilic interaction chromatography analysis of the released N-glycans and intact mass characterization confirmed the high di-sialylation of Herceptin via the optimized one-pot three-enzyme reaction. This study established a versatile enzymatic approach for producing highly di-sialylated IgG antibodies. It provides new insights into engineering bacterial sialyltransferase for adaptation to the enzymatic glycoengineering of therapeutic antibodies and the glycosite-specific conjugation of antibodies.
- Published
- 2020
9. C-Glycosylation enabled by N-(glycosyloxy)acetamides
- Author
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Xia Wu, De-Cai Xiong, Bo-Han Li, Meng Liu, Miao Liu, Tian Li, and Xin-Shan Ye
- Subjects
Reaction conditions ,chemistry.chemical_classification ,Glycosylation ,Silylation ,Aryl ,Organic Chemistry ,Biochemistry ,Enol ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Organic chemistry ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Phenols ,Physical and Theoretical Chemistry ,Alkyl - Abstract
The C-glycosylation of C-nucleophiles including allyltrimethylsilane, silyl enol ethers and phenols with N-(glycosyloxy)acetamides as glycosyl donors has been realized. This protocol provides a convenient and practical route for the synthesis of alkyl C-glycosides and aryl 2-deoxy-β-C-glycosides under mild reaction conditions.
- Published
- 2020
10. Total synthesis of tumor-associated KH-1 antigen core nonasaccharideviaphoto-induced glycosylation
- Author
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Congying Wu, Hong Yang, Bo-Han Li, Yuxin Yin, De-Cai Xiong, Wenlong Yao, and Xin-Shan Ye
- Subjects
carbohydrates (lipids) ,chemistry.chemical_classification ,chemistry.chemical_compound ,Glycosylation ,KH-1 antigen ,Antigen ,Chemistry ,Stereochemistry ,Organic Chemistry ,Core (graph theory) ,Total synthesis ,lipids (amino acids, peptides, and proteins) ,Glycosidic bond - Abstract
The synthesis of tumor-associated KH-1 antigen core nonasaccharide was achieved. All key glycosidic linkages were efficiently constructed by photo-induced glycosylation. The success of this total synthesis provides an example for the preparation of complex oligosaccharides using light-driven glycosylation reactions.
- Published
- 2020
11. Protecting Groups in Carbohydrate Chemistry: Influence on Stereoselectivity of Glycosylations
- Author
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Jian Guo and Xin-Shan Ye
- Subjects
protecting group ,stereoselectivity ,glycosylation ,carbohydrate ,Organic chemistry ,QD241-441 - Abstract
Saccharides are polyhydroxy compounds, and their synthesis requires complex protecting group manipulations. Protecting groups are usually used to temporarily mask a functional group which may interfere with a certain reaction, but protecting groups in carbohydrate chemistry do more than protecting groups usually do. Particularly, protecting groups can participate in reactions directly or indirectly, thus affecting the stereochemical outcomes, which is important for synthesis of oligosaccharides. Herein we present an overview of recent advances in protecting groups influencing stereoselectivity in glycosylation reactions, including participating protecting groups, and conformation-constraining protecting groups in general.
- Published
- 2010
- Full Text
- View/download PDF
12. Glycan Assembly Strategy: From Concept to Application
- Author
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Xianjin Qin, Mingli Liu, and Xin-Shan Ye
- Subjects
Glycan ,Glycosylation ,biology ,Carbohydrate chemistry ,Chemistry ,General Chemical Engineering ,Carbohydrate synthesis ,General Chemistry ,Computational biology ,Biochemistry ,carbohydrates (lipids) ,chemistry.chemical_compound ,Hot topics ,Polysaccharides ,Materials Chemistry ,Natural source ,biology.protein - Abstract
Glycans have been hot topics in recent years due to their exhibition of numerous biological activities. However, the heterogeneity of their natural source and the complexity of their chemical synthesis impede the progress in their biological research. Thus, the development of glycan assembly strategies to acquire plenty of structurally well-defined glycans is an important issue in carbohydrate chemistry. In this review, the latest advances in glycan assembly strategies from concepts to their applications in carbohydrate synthesis, including chemical and enzymatic/chemo-enzymatic approaches, as well as solution-phase and solid-phase/tag-assisted synthesis, are summarized. Furthermore, the automated glycan assembly techniques are also outlined.
- Published
- 2021
13. Rapid glycosylation of 2′-benzoylphenyl glycosides promoted by TfOH
- Author
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Da-Ke Liu, Qin Li, De-Cai Xiong, Xia Wu, and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,Glycosylation ,010405 organic chemistry ,Organic Chemistry ,Glycoside ,Substrate (chemistry) ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,lipids (amino acids, peptides, and proteins) ,Glycosyl - Abstract
A new glycosylation protocol based on 2′-benzoylphenyl glycosides has been developed. These glycosyl donors could be rapidly activated by TfOH at room temperature. The donors are readily available. The reaction exhibited a broad substrate scope and coupled products were obtained in high yields.
- Published
- 2019
14. Total Synthesis of a Hyperbranched N ‐Linked Hexasaccharide Attached to ATCV‐1 Major Capsid Protein without Precedent
- Author
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Yong Wu, Yong-Shi Wang, Xin-Shan Ye, and De-Cai Xiong
- Subjects
Glycosylation ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Total synthesis ,Regioselectivity ,General Chemistry ,010402 general chemistry ,medicine.disease_cause ,01 natural sciences ,Chemical synthesis ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry.chemical_compound ,Capsid ,medicine ,Acanthocystis turfacea Chlorella virus 1 - Abstract
Summary of main observation and conclusion The N-glycans attached to some chloroviruses comprise a hyperbranched core structure without precedent. We are interested in the chemical synthesis of the hexasaccharide attached to ATCV-1 (Acanthocystis turfacea Chlorella virus 1) for its distinct structure. After exploring four routes, the target hexasaccharide 2 was successfully synthesized for the first time in overall 10% yield over 8 steps from thioglycoside building blocks. This synthetic protocol is characterized by the three-component one-pot glycosylation and the regioselective glycosylation reactions. The disclosed synthetic approach to this new type of N-glycans will facilitate the in-depth understanding of their biological functions.
- Published
- 2018
15. Chemical synthesis of glycans and applications in carbohydrate-based vaccines
- Author
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Yongshi Wang and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,Glycan ,Glycosylation ,Glycobiology ,Glycoconjugate ,General Chemical Engineering ,Immunogenicity ,General Chemistry ,Biology ,Carbohydrate ,Polysaccharide ,Biochemistry ,Chemical synthesis ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,biology.protein - Abstract
Carbohydrates play important roles in many biological processes. However, the lack of resources of structurally-defined carbohydrates and their weak immunogenicity have always restricted the development of chemical glycobiology especially carbohydrate-based vaccines. The progress in chemical synthesis of carbohydrates and glycoconjugates has greatly promoted the development of carbohydrate-based vaccines including antibacterial vaccines, anti-tumor vaccines and anti-HIV vaccines. The use of one-pot glycosylation strategy and solid-phase glycosylation strategy is able to synthesize oligosaccharides and even polysaccharides more effectively than before. Glycoconjugates produced by combining the carbohydrate antigens and proper protein carriers improve the immunogenicity of carbohydrates. This review covers the general methods and strategies of carbohydrate chemical synthesis, and the recent development of carbohydrate-based vaccines, and also summarizes related work of our group, hoping to offer readers better understanding of chemical glycobiology especially carbohydrate-based vaccines.
- Published
- 2018
16. Iterative Synthesis of 2‐Deoxyoligosaccharides Enabled by Stereoselective Visible‐Light‐Promoted Glycosylation.
- Author
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Liu, Kai‐Meng, Wang, Peng‐Yu, Guo, Zhen‐Yan, Xiong, De‐Cai, Qin, Xian‐Jin, Liu, Miao, Liu, Meng, Xue, Wan‐Ying, and Ye, Xin‐Shan
- Subjects
GLYCOSYLATION ,CHEMICAL yield ,ENOLS ,DIGOXIN ,STEREOSELECTIVE reactions - Abstract
The photoinitiated intramolecular hydroetherification of alkenols has been used to form C−O bonds, but the intermolecular hydroetherification of alkenes with alcohols remains an unsolved challenge. We herein report the visible‐light‐promoted 2‐deoxyglycosylation of alcohols with glycals. The glycosylation reaction was completed within 2 min in a high quantum yield (ϕ=28.6). This method was suitable for a wide array of substrates and displayed good reaction yields and excellent stereoselectivity. The value of this protocol was further demonstrated by the iterative synthesis of 2‐deoxyglycans with α‐2‐deoxyglycosidic linkages up to a 20‐mer in length and digoxin with β‐2‐deoxyglycosidic linkages. Mechanistic studies indicated that this reaction involved a glycosyl radical cation intermediate and a photoinitiated chain process. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
17. A five-component one-pot synthesis of phosphatidylinositol pentamannoside (PIM5)
- Author
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Xin-Shan Ye, De-Cai Xiong, and Dong Wang
- Subjects
chemistry.chemical_compound ,Glycosylation ,chemistry ,010405 organic chemistry ,Stereochemistry ,One-pot synthesis ,Regioselectivity ,Inositol ,General Chemistry ,Phosphatidylinositol ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences - Abstract
A practical and efficient synthesis of phosphatidylinositol pentamannoside (PIM5) was achieved based on a five-component one-pot sequential glycosylation protocol with exclusive regio- and stereo-selectivity. Two regioselective sequential glycosylations on inositol and p-tolyl thioglycosides as the sole type of building blocks made this protocol to avoid the tedious protective group manipulations. This synthetic strategy provides access to other important glycolipids with similar structures.
- Published
- 2018
18. Transition State-Based Sialyltransferase Inhibitors: Mimicking Oxocarbenium Ion by Simple Amide
- Author
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Jian Guo, Wenming Li, Weiwei Xue, and Xin-Shan Ye
- Subjects
0301 basic medicine ,Magnetic Resonance Spectroscopy ,Glycosylation ,Sialyltransferase ,Stereochemistry ,Oxocarbenium ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Amide ,Drug Discovery ,Humans ,Moiety ,Enzyme Inhibitors ,Chromatography, High Pressure Liquid ,chemistry.chemical_classification ,biology ,010405 organic chemistry ,Nuclear magnetic resonance spectroscopy ,Amides ,Sialyltransferases ,0104 chemical sciences ,Sialic acid ,carbohydrates (lipids) ,030104 developmental biology ,Enzyme ,chemistry ,biology.protein ,Molecular Medicine ,Spectrophotometry, Ultraviolet - Abstract
In the new transition-state based sialyltransferase inhibitors, an amide group was placed at the corresponding C-2 position of CMP-sialic acid to mimic the geometry and charge distribution in the transition state, and simple aromatic or aliphatic rings were used instead of the sialic acid moiety. All synthetic compounds exhibited excellent α(2-6)-sialyltransferase inhibition, resulting in up to a 2600-fold higher affinity for the enzyme than CMP-Neu5Ac, suggesting that amide is a key element for simulating transition-state features.
- Published
- 2017
19. Glycan Assembly Strategy: From Concept to Application.
- Author
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Liu, Mingli, Qin, Xianjin, and Ye, Xin‐Shan
- Subjects
CHEMICAL synthesis ,GLYCANS ,CARBOHYDRATES - Abstract
Glycans have been hot topics in recent years due to their exhibition of numerous biological activities. However, the heterogeneity of their natural source and the complexity of their chemical synthesis impede the progress in their biological research. Thus, the development of glycan assembly strategies to acquire plenty of structurally well‐defined glycans is an important issue in carbohydrate chemistry. In this review, the latest advances in glycan assembly strategies from concepts to their applications in carbohydrate synthesis, including chemical and enzymatic/chemo‐enzymatic approaches, as well as solution‐phase and solid‐phase/tag‐assisted synthesis, are summarized. Furthermore, the automated glycan assembly techniques are also outlined. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
20. Visible-light-promoted 3,5-dimethoxyphenyl glycoside activation and glycosylation.
- Author
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Cao, Yafei, Zhou, Minmin, Mao, Run-Ze, Zou, You, Xia, Feng, Liu, Da-Ke, Liu, Jianhui, Li, Qin, Xiong, De-Cai, and Ye, Xin-Shan
- Subjects
GLYCOSYLATION ,VISIBLE spectra ,BASE pairs ,GLYCOSIDES - Abstract
A new glycosylation method promoted by visible light with 3,5-dimethoxyphenyl glycoside as the donor was developed. This protocol delivers both O-glycosides and N-glycosides in moderate to excellent yields using a wide range of O-nucleophiles and nucleobases as the glycosyl acceptors. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
21. 3-Butenyloxycarbonyl as a new hydroxyl protecting group in carbohydrate synthesis
- Author
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Xin-Shan Ye, Youhong Niu, and Nana Zeng
- Subjects
Glycosylation ,010405 organic chemistry ,Organic Chemistry ,Carbohydrate synthesis ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,Organic chemistry ,Oxidative cleavage ,Protecting group - Abstract
3-Butenyloxycarbonyl (Bloc) has been identified as a new hydroxyl protecting group, which can be introduced under mild conditions in high yields and selectively removed by OsO4/NaIO4/2,6-lutidine in CH3CN–H2O without affecting most commonly-used protecting groups. Moreover, this new protecting group is inert under glycosylation conditions.
- Published
- 2016
22. Stereoselective Koenigs-Knorr Glycosylation Catalyzed by Urea
- Author
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Xiaowei Wu, Xin-Shan Ye, De-Cai Xiong, and Lifeng Sun
- Subjects
animal structures ,Anomer ,Glycosylation ,Stereochemistry ,010405 organic chemistry ,fungi ,macromolecular substances ,General Chemistry ,General Medicine ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Organocatalysis ,Urea ,Organic chemistry ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Stereoselectivity ,Selectivity ,Phosphine - Abstract
A stereoselective Koenigs-Knorr glycosylation reaction under the catalysis of urea is described. This method is characterized by urea-mediated hydrogen-bond activation and subsequent glycosylation with glycosyl chlorides or bromides. Excellent yields and high anomeric selectivity can be achieved in most cases. Moreover, the low α-stereoselectivity of glycosylations observed when using perbenzylated glucosyl donors can be greatly improved by the addition of tri-(2,4,6-trimethoxyphenyl)phosphine (TTMPP).
- Published
- 2016
23. Light-driven highly efficient glycosylation reactions
- Author
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Runze Mao, Xin-Shan Ye, De-Cai Xiong, Qin Li, Jinyou Duan, and Fan Guo
- Subjects
Glycosylation ,010405 organic chemistry ,Organic Chemistry ,Substrate (chemistry) ,010402 general chemistry ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Light driven ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Organic synthesis - Abstract
Glycosylation is unarguably the most important reaction in the field of glycochemistry. Photo-initiated reactions hold extraordinary potential in organic synthesis. Herein we report a novel light-driven strategy for the activation of thioglycosides via the merger of a CF3 radical pathway followed by the subsequent glycosylation with glycosyl acceptors. This protocol could efficiently activate thioglycosides, thereby greatly enhancing the substrate scope of reactions. In particular, the glycosylation reactions, which are completely inert under the existing photo-induced glycosylation conditions, proceeded smoothly in high yields. Many common protective groups were well tolerated under the coupling conditions. Both UV and visible light or even sunlight were used as the source of light for the reactions. The high efficiency of this light-driven glycosylation protocol was further highlighted by the rapid one-pot sequential assembly of oligosaccharides.
- Published
- 2016
24. Donor Preactivation‐Based Glycosylation: An Efficient Strategy for Glycan Synthesis.
- Author
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Qin, Xianjin and Ye, Xin‐Shan
- Subjects
- *
GLYCANS , *GLYCOSYLATION , *CLINICAL chemistry , *PROBLEM solving , *CREATIVE thinking , *GRADUATE education - Abstract
Carbohydrates have gained a lot of appreciation in the past few decades due to their important roles in numerous biological events. Acquiring a structurally well‐defined carbohydrate compound is essential for the understanding of its functions. Although some innovative methods have been developed for the synthesis of complex oligosaccharides, glycan synthesis is in general still a time‐consuming and difficult work. Herein, we will introduce the preactivation‐based glycosylation strategy, which is an efficient protocol independent of the reactivity of glycosyl donor. This review will focus on summarizing the versatile applications of preactivation strategy in stereoselective glycosylation and one‐pot assembly of biologically important oligosaccharides and even polysaccharides. What is the most favorite and original chemistry developed in your research group? Preactivation‐based one‐pot glycosylation strategy and applications. How do you get into this specific field? Could you please share some experiences with our readers? I got into this field when I was a research associate in 1996. My supervisor, Prof. Chi‐Huey Wong, gave me a research topic for synthesis of oligosaccharide libraries. At that moment, as a beginner, I did not know too much carbohydrate chemistry, just to learn and to do it. The importance and challenge of carbohydrates attracted me. What is the most important personality for scientific research? Curiosity, passion, and creative thinking. How do you supervise your students? In my opinion, before the graduate students start a specific project, their experimental skills need to be well trained. During the period of graduate studies, the enhancement of abilities to analyze problems and to solve problems is very important. The graduate students should always keep an eye on the unusual experimental phenomena. What's your hobbies? Reading history books. What is your favorite journals? The journals publishing the latest research works in chemistry and medical science. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
25. O-Glycosylation Enabled by N-(Glycosyloxy)acetamides
- Author
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Xin-Shan Ye, Bo-Han Li, De-Cai Xiong, and Miao Liu
- Subjects
Glycosylation ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Chemical glycosylation ,Leaving group ,Substrate (chemistry) ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,chemistry.chemical_compound ,Microwave irradiation ,Glycosyl ,Oligosaccharide synthesis - Abstract
A novel glycosylation protocol has been established by using N-(glycosyloxy)acetamides as glycosyl donors. The N-oxyacetamide leaving group in donors could be rapidly activated in the presence of Cu(OTf)2 or SnCl4 under microwave irradiation. This glycosylation process afforded the coupled products in high yields, and the reaction enjoyed a broad substrate scope, even for disarmed donors and hindered acceptors. The easy availability of the donors, the high stability of N-(glycosyloxy)acetamides, and the small leaving group make this method very practical.
- Published
- 2018
26. Additive-controlled stereoselective glycosylations of 2,3-oxazolidinone protected glucosamine or galactosamine thioglycoside donors with phenols based on preactivation protocol
- Author
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Xin-Shan Ye, Qi Qin, and De-Cai Xiong
- Subjects
chemistry.chemical_classification ,Glucosamine ,Glycosylation ,Organic Chemistry ,Glycoside ,Galactosamine ,Stereoisomerism ,General Medicine ,Biochemistry ,Substrate Specificity ,Analytical Chemistry ,chemistry.chemical_compound ,Phenols ,chemistry ,Thioglycosides ,Phenol ,Organic chemistry ,Stereoselectivity ,Oxazolidinones - Abstract
Stereo-controllable glycosylation reactions of 2,3-oxazolidinone protected glucosamine thioglycoside donor with different phenol acceptors based on preactivation protocol, are described. It was found that BF3·Et2O worked as α-directing additive, while TTBP acted as β-directing additive. Simply by altering additives, either α-aryl glycosides or β-aryl glycosides were achieved in a stereoselective manner. The additives were also applied to the stereoselective glycosylation reactions of 2,3-oxazolidinone protected galactosamine donor with phenol substrates.
- Published
- 2015
27. KOtBu-mediated aromatic O-glycosylation of 1,2-anhydrosugar and aryl boronic acid
- Author
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Chen-Fu Liu, De-Cai Xiong, and Xin-Shan Ye
- Subjects
inorganic chemicals ,chemistry.chemical_classification ,Glycosylation ,010405 organic chemistry ,Aryl ,Organic Chemistry ,Glycoside ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Reagent ,Drug Discovery ,Organic chemistry ,Stereoselectivity ,Organic synthesis ,Boronic acid - Abstract
A new approach for the synthesis of phenolic glycosides via aromatic O-glycosylation of 1,2-anhydrosugar and aryl boronic acids was disclosed. This method is characterized by the use of aryl boronic acid as the aryl source and produces phenolic glycosides in a stereoselective manner. This reaction provides an alternative approach to the synthesis of phenolic glycosides. It also represents a new application of aryl boronic acids as versatile reagents in organic synthesis.
- Published
- 2016
28. Total synthesis of mycobacterial arabinogalactan containing 92 monosaccharide units
- Author
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Yong-Shi Wang, Xin-Shan Ye, Si-Cong Chen, De-Cai Xiong, and Yong Wu
- Subjects
Glycosylation ,Science ,General Physics and Astronomy ,010402 general chemistry ,Polysaccharide ,01 natural sciences ,Chemical synthesis ,Galactans ,General Biochemistry, Genetics and Molecular Biology ,Article ,Mycobacterium ,Cell wall ,chemistry.chemical_compound ,Arabinogalactan ,Monosaccharide ,chemistry.chemical_classification ,Multidisciplinary ,Molecular Structure ,010405 organic chemistry ,Monosaccharides ,Polysaccharides, Bacterial ,Total synthesis ,Stereoisomerism ,General Chemistry ,Oligosaccharide ,0104 chemical sciences ,Biochemistry ,chemistry ,Carbohydrate Sequence ,Models, Chemical - Abstract
Carbohydrates are diverse bio-macromolecules with highly complex structures that are involved in numerous biological processes. Well-defined carbohydrates obtained by chemical synthesis are essential to the understanding of their functions. However, synthesis of carbohydrates is greatly hampered by its insufficient efficiency. So far, assembly of long carbohydrate chains remains one of the most challenging tasks for synthetic chemists. Here we describe a highly efficient assembly of a 92-mer polysaccharide by the preactivation-based one-pot glycosylation protocol. Several linear and branched oligosaccharide/polysaccharide fragments ranging from 5-mer to 31-mer in length have been rapidly constructed in one-pot manner, which enables the first total synthesis of a biologically important mycobacterial arabinogalactan through a highly convergent [31+31+30] coupling reaction. Our results show that the preactivation-based one-pot glycosylation protocol may provide access to the construction of long and complicated carbohydrate chains., Due to the vast number of potential isomers, the chemical synthesis of large carbohydrates is challenging. Here the authors report the synthesis of mycobacterial arabinogalactan, a biologically important natural product composed of 92 monosaccharide units, the largest synthetic polysaccharide to date.
- Published
- 2017
29. ChemInform Abstract: Stereoselective Koenigs-Knorr Glycosylation Catalyzed by Urea
- Author
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Xiaowei Wu, Lifeng Sun, Xin-Shan Ye, and De-Cai Xiong
- Subjects
animal structures ,Glycosylation ,Anomer ,Stereochemistry ,fungi ,macromolecular substances ,General Medicine ,Catalysis ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Urea ,lipids (amino acids, peptides, and proteins) ,Stereoselectivity ,Glycosyl ,Selectivity ,Phosphine - Abstract
A stereoselective Koenigs-Knorr glycosylation reaction under the catalysis of urea is described. This method is characterized by urea-mediated hydrogen-bond activation and subsequent glycosylation with glycosyl chlorides or bromides. Excellent yields and high anomeric selectivity can be achieved in most cases. Moreover, the low α-stereoselectivity of glycosylations observed when using perbenzylated glucosyl donors can be greatly improved by the addition of tri-(2,4,6-trimethoxyphenyl)phosphine (TTMPP).
- Published
- 2016
30. Stereoselective Electro‐2‐deoxyglycosylation from Glycals.
- Author
-
Liu, Miao, Liu, Kai‐Meng, Xiong, De‐Cai, Zhang, Hanyu, Li, Tian, Li, Bohan, Qin, Xianjin, Bai, Jinhe, and Ye, Xin‐Shan
- Subjects
GLYCALS ,NATURAL products ,PODOPHYLLOTOXIN ,STEREOSELECTIVE reactions - Abstract
We report a novel and highly stereoselective electro‐2‐deoxyglycosylation from glycals. This method features excellent stereoselectivity, scope, and functional‐group tolerance. This process can also be applied to the modification of a wide range of natural products and drugs. Furthermore, a scalable synthesis of glycosylated podophyllotoxin and a one‐pot trisaccharide synthesis through iterative electroglycosylations were achieved. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
31. Preactivation: An Alternative Strategy in Stereoselective Glycosylation and Oligosaccharide Synthesis
- Author
-
Xin-Shan Ye, Qi Qin, and Lin Yang
- Subjects
chemistry.chemical_classification ,Chiral auxiliary ,Glycosylation ,Organic Chemistry ,Oligosaccharide ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Biochemistry ,lipids (amino acids, peptides, and proteins) ,Stereoselectivity ,Protecting group ,Oligosaccharide synthesis ,Alternative strategy - Abstract
The multifaceted biological importance of carbohydrates has made them very popular targets in modern synthetic chemistry. Great progress has been made in stereoselective glycosylation methods and the construction of complex oligosaccharides. This Focus Review highlights the versatile applications of preactivation strategies in stereoselective glycosylation and oligosaccharide synthesis. Recent advances in synthetic methods, such as 4,6-O-benzylidene-acetal-directed β-mannosylation, the 1,2-cis-glycosylation mediated by a chiral auxiliary, the use of an oxazolidinone or carbonate protecting group, and glycosylation with participating additives, are described. Various examples of sequential glycosylation based on preactivation protocols for efficient oligosaccharide assembly are also summarized.
- Published
- 2013
32. Syntheses of novel acarviosin analogs with anhydro or unsaturated sugar moieties
- Author
-
Xin-Shan Ye, De-Cai Xiong, Qin Li, Yuan Wang, and Yuan-Yuan Wang
- Subjects
chemistry.chemical_classification ,Glycosylation ,Chemistry ,Stereochemistry ,Organic Chemistry ,Disaccharide ,Epoxide ,Glycoside ,Biochemistry ,Chemical synthesis ,chemistry.chemical_compound ,Drug Discovery ,Organic chemistry ,Glycosyl ,Sugar ,Protecting group - Abstract
A new class of pseudoacarviosins with 2,3-anhydro or unsaturated sugar moieties were synthesized efficiently. The designed target disaccharides were constructed by the glycosylation reactions using 2,3-anhydromonosaccharides as glycosyl donors. The glycosylation reactions were carried out in a highly stereoselective manner in most cases, especially when the preactivation protocol was used. The anhydrosugar units of disaccharides were kept intact during the deprotection operations of protective groups. Furthermore, the disaccharides containing anhydrosugar moieties were smoothly converted to the unsaturated disaccharides via the base-promoted rearrangement of sugar epoxides.
- Published
- 2012
33. ChemInform Abstract: KOtBu-Mediated Aromatic O-Glycosylation of 1,2-Anhydrosugar and Aryl Boronic Acid
- Author
-
Chen-Fu Liu, De-Cai Xiong, and Xin-Shan Ye
- Subjects
inorganic chemicals ,chemistry.chemical_classification ,chemistry.chemical_compound ,Glycosylation ,chemistry ,Suzuki reaction ,Aryl ,Glycoside ,Organic chemistry ,General Medicine ,Boronic acid - Abstract
A new useful method for the synthesis of phenolic glycosides by the reaction of 1,2-anhydrosugars with aryl boronic acids is reported.
- Published
- 2016
34. ChemInform Abstract: Photoinduced C-S Bond Cleavage of Thioglycosides and Glycosylation
- Author
-
Jinyou Duan, De-Cai Xiong, Xin-Shan Ye, Fan Guo, Qin Li, and Runze Mao
- Subjects
chemistry.chemical_classification ,In situ ,Terpene ,chemistry.chemical_compound ,Glycosylation ,chemistry ,lipids (amino acids, peptides, and proteins) ,General Medicine ,Combinatorial chemistry ,Trifluoromethanesulfonate ,Bond cleavage ,Amino acid - Abstract
Activation of thioglycosides upon UV irradiation followed by cupric triflate oxidation leads to the in situ formation of an oxacarbenium ion which is able to undergo glycosylation reactions with a wide variety of substrates such as sugars, amino acids, terpenes, and sterols.
- Published
- 2016
35. Photoinduced C-S Bond Cleavage of Thioglycosides and Glycosylation
- Author
-
Runze Mao, Fan Guo, Qin Li, Xin-Shan Ye, De-Cai Xiong, and Jinyou Duan
- Subjects
chemistry.chemical_classification ,animal structures ,Glycosylation ,Molecular Structure ,Organic Chemistry ,macromolecular substances ,Photochemistry ,Photochemical Processes ,Biochemistry ,Medicinal chemistry ,Coupling reaction ,Amino acid ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Thioglycosides ,Yield (chemistry) ,Molecule ,lipids (amino acids, peptides, and proteins) ,Photosensitizer ,Glycosyl ,Glycosides ,Physical and Theoretical Chemistry ,Bond cleavage - Abstract
A glycosyl coupling reaction via photoinduced direct activation of thioglycosides and subsequent O-glycosylation in the absence of photosensitizer was developed for the first time. This reaction underwent a selectively homolytic cleavage of a C–S bond to generate a glycosyl radical, which was oxidized to an oxacarbenium ion by Cu(OTf)2, and a sequential O-glycosylation. A wide range of glycosides were synthesized in moderate to excellent yield using sugars, amino acids, or cholesterol as the acceptors.
- Published
- 2015
36. O,O-Dimethylthiophosphonosulfenyl bromide-silver triflate: a new powerful promoter system for the preactivation of thioglycosides
- Author
-
Xin-Shan Ye and Peng Peng
- Subjects
Bromides ,Mesylates ,chemistry.chemical_classification ,Glycosylation ,Molecular Structure ,Chemistry ,Stereochemistry ,Organic Chemistry ,Oligosaccharides ,Silver Compounds ,food and beverages ,Organothiophosphorus Compounds ,Glycosidic bond ,Oligosaccharide ,Biochemistry ,chemistry.chemical_compound ,Thioglycosides ,Bromide ,Molecule ,Glycosyl ,Physical and Theoretical Chemistry ,Trifluoromethanesulfonate - Abstract
O,O-Dimethylthiophosphonosulfenyl bromide (DMTPSB) in combination with silver triflate provides a powerful thiophilic promoter system. Both "armed" and "disarmed" thioglycoside glycosyl donors can be activated to form glycosidic linkages efficiently by the pre-activation protocol. The usefulness of this new promoter is illustrated by a successful iterative one-pot oligosaccharide assembly.
- Published
- 2011
37. Additive-Controlled Stereoselective Glycosylations of Oxazolidinone-Protected Glucosamine and Galactosamine Thioglycoside Donors Based on Preactivation Protocol
- Author
-
Yiqun Geng and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,chemistry.chemical_compound ,Glycosylation ,chemistry ,Amino sugar ,Galactosamine ,Organic Chemistry ,Thiophene ,Organic chemistry ,Stereoselectivity ,Bifunctional ,Selectivity ,Ammonium iodide - Abstract
Based on a pre-activation protocol, the stereoselectivity of oxazolidinone-protected amino sugar thioglycoside donors towards glycosylations can be controlled by additives. Either α- or β-selectivity could be obtained by changing additives. 2,4,6-Tri-tert-butylpyrimidine (TTBP) was the best β-directing additive, while thiophene worked as the best α-directing additive. The bifunctional additives such as tetrabutyl ammonium iodide (TBAI) afforded either α- or β-selectivity depending on the amount added. Poor α-selectivity of some glycosylations without any additives was greatly improved by adding TBAI or thiophene.
- Published
- 2010
38. A highly α-selective glycosylation for the convenient synthesis of repeating α-(1→4)-linked N-acetyl-galactosamine units
- Author
-
Lin Yang and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,Glycosylation ,Molecular Structure ,Stereochemistry ,Biomolecule ,Molecular Sequence Data ,Organic Chemistry ,Galactosamine ,Stereoisomerism ,General Medicine ,Polysaccharide ,Biochemistry ,Analytical Chemistry ,chemistry.chemical_compound ,Carbohydrate Sequence ,chemistry ,Yield (chemistry) ,Glycosyl donor ,Glycoprotein - Abstract
The repeating GalpNAc-alpha-(1--4)-GalpNAc unit is part of a series of essential structures that can be found in many important biomolecules such as the glycoproteins and the O-antigenic polysaccharides of clinically important bacterial strains. In this paper, we describe an exclusive alpha-selective glycosylation reaction, using a 4,6-di-O-tert-butyldimethylsilyl-N-acetyloxazolidinone-protected thioglycoside as the glycosyl donor, under pre-activation conditions, with only half amount of the promoter, providing the product GalpNAc-alpha-(1--4)-GalpNAc in high isolated yield. This reaction can be also applied to increasing the length of the repeating structure, which is of significant use in further synthesis of branched or linear oligosaccharides.
- Published
- 2010
39. Direct α-Selective Glycosylations of Acetyl-Protected 2-Deoxy- and 2,6-Dideoxythioglycosides by Preactivation Protocol
- Author
-
Yin-Suo Lu, Xin-Shan Ye, Qin Li, and Yuan Wang
- Subjects
carbohydrates (lipids) ,chemistry.chemical_compound ,animal structures ,Glycosylation ,chemistry ,Organic Chemistry ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,macromolecular substances ,Carbohydrate ,Combinatorial chemistry - Abstract
An efficient preactivation protocol for the highly α-stereo-selective glycosylation of2-deoxy- and 2,6-dideoxysugars has been developed using acetyl-protected 2-deoxy- and 2,6-dideoxythioglycosides as glycosyl donors. The approach allows a wide range of glycosyl acceptors and donors to be used.
- Published
- 2010
40. Sialylation reactions with N,N-acetyl, benzoyl-O-perbenzoyl-protected sialyl donor
- Author
-
Yue Wang and Xin-Shan Ye
- Subjects
carbohydrates (lipids) ,chemistry.chemical_compound ,Anomer ,Glycosylation ,chemistry ,Stereochemistry ,Organic Chemistry ,Drug Discovery ,Stereoselectivity ,Carbohydrate ,Selectivity ,Biochemistry ,Dichloromethane - Abstract
A new sialyl donor, N , N -acetyl, benzoyl- O -perbenzoyl-protected p -toluenethiosialoside, was synthesized and its sialylation reaction was investigated. This reaction proceeded in dichloromethane and β anomeric selectivity was achieved when NIS–TfOH was used as promoter. This method may be employed to construct the unnatural β-linked sialosides.
- Published
- 2009
41. Oxidant-Controlled Heck-Type C-Glycosylation of Glycals with Arylboronic Acids: Stereoselective Synthesis of Aryl 2-Deoxy-C-glycosides
- Author
-
De-Cai Xiong, Xin-Shan Ye, and Li‐He Zhang
- Subjects
chemistry.chemical_classification ,Glycosylation ,Ketone ,Molecular Structure ,Aryl ,Organic Chemistry ,Stereoisomerism ,Oxidants ,Boronic Acids ,Biochemistry ,Medicinal chemistry ,Benzoquinone ,Catalysis ,chemistry.chemical_compound ,chemistry ,Ethers, Cyclic ,Benzoquinones ,Enol ether ,Combinatorial Chemistry Techniques ,Stereoselectivity ,Glycosides ,Physical and Theoretical Chemistry ,Enone - Abstract
Oxidative Heck-type C-glycosylations of glycals with various arylboronic acids using Pd(OAc)(2) as catalyst in the presence of oxidant were developed. The corresponding ketone, enol ether, and enone types of C-glycosides were predictably obtained with benzoquinone (BQ), Cu(OAc)(2)/O(2), and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as oxidants, respectively. This method provides a simple, mild, and stereoselective synthesis of aryl 2-deoxy-C-glycosides.
- Published
- 2009
42. Bromodimethylsulfonium Bromide-Silver Triflate: A New Powerful Promoter System for the Activation of Thioglycosides
- Author
-
Lihe Zhang, Xin-Shan Ye, and De-Cai Xiong
- Subjects
chemistry.chemical_classification ,chemistry.chemical_compound ,Glycosylation ,chemistry ,Bromide ,Organic chemistry ,Reactivity (chemistry) ,Glycosidic bond ,General Chemistry ,Oligosaccharide ,Trifluoromethanesulfonate - Abstract
Bromodimethylsulfonium bromide (BDMS) in combination with silver triflate provides a very efficient thiophilic promoter system, capable of activating both "disarmed" and "armed" thioglycosides for glycosidic bond formation. The usefulness of this new promoter is illustrated by a successful reactivity-based one-pot oligosaccharide assembly.
- Published
- 2008
43. Stereoselectivity investigation on glycosylation of oxazolidinone protected 2-amino-2-deoxy-d-glucose donors based on pre-activation protocol
- Author
-
Xin-Shan Ye, Yiqun Geng, and Lihe Zhang
- Subjects
animal structures ,Glycosylation ,Stereochemistry ,Organic Chemistry ,macromolecular substances ,Carbohydrate ,Biochemistry ,Coupling reaction ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Stereoselectivity ,2-Deoxy-D-glucose ,Selectivity ,Pre activation - Abstract
Diverse 2,3-oxazolidinone protected 2-amino-2-deoxy- d -glucose thioglycosides were prepared and studied as glycosyl donors at low temperature by BSM/Tf2O pre-activation protocol before the addition of glycosyl acceptors. The stereochemistry outcomes of a series of glycosylations were investigated. Different stereoselectivities of the coupling reactions were obtained, arising from the different protecting groups in the oxazolidinone donors. 4,6-Di-O-benzyl-N-benzyl-oxazolidinone protected thioglycoside donor 1c underwent glycosylation with general β-anomeric selectivity and the stereoselectivity could be also affected by glycosylation conditions.
- Published
- 2008
44. Syntheses of LewisX and Dimeric LewisX: Construction of Branched Oligosaccharides by a Combination of Preactivation and Reactivity Based Chemoselective One-Pot Glycosylations
- Author
-
Xuefei Huang, Youlin Zeng, Adeline Miermont, Yuqing Jing, and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,Glycosylation ,Anomer ,Chemistry ,Stereochemistry ,Molecular Sequence Data ,Organic Chemistry ,Oligosaccharides ,Regioselectivity ,Oligosaccharide ,Chemical synthesis ,Article ,Lewis Blood Group Antigens ,Carbohydrate Sequence ,Carbohydrate Conformation ,Combinatorial Chemistry Techniques ,Reactivity (chemistry) ,Carbohydrate conformation ,Chemoselectivity ,Protecting group - Abstract
Two asymmetrically branched oligosaccharides, LewisX and dimeric LewisX, were assembled in one pot with high yields and exclusive regio- and stereoselectivities. p-Tolyl thioglycosides were utilized as the sole type of building blocks, thus simplifying the overall synthetic design. The reactivity-independent nature of the preactivation based method allows modular assembly of the dimeric LewisX octasaccharide without the need for tedious protective group manipulation to achieve exact anomeric reactivities.
- Published
- 2007
45. Improvement of the immune efficacy of carbohydrate vaccines by chemical modification on the GM3 antigen
- Author
-
Fan Yang, Xin-Shan Ye, Ye Zhang, Mingwei Zheng, Xiu-Jing Zheng, and Chang-Xin Huo
- Subjects
endocrine system ,Glycosylation ,Glycoconjugate ,medicine.medical_treatment ,Molecular Conformation ,Biochemistry ,Antigen-Antibody Reactions ,chemistry.chemical_compound ,Immune system ,Cancer immunotherapy ,Antigen ,medicine ,G(M3) Ganglioside ,Physical and Theoretical Chemistry ,Antigens ,chemistry.chemical_classification ,Vaccines ,biology ,Chemistry ,Immunogenicity ,Organic Chemistry ,Virology ,carbohydrates (lipids) ,Vaccination ,Immunology ,biology.protein ,lipids (amino acids, peptides, and proteins) ,Antibody - Abstract
Tumor cells often display aberrant levels and patterns of cell surface glycosylation, which provides a potential opportunity to develop carbohydrate-based anticancer vaccines for cancer immunotherapy. However, one of the most addressed challenges in this field is the low efficiency of the carbohydrate vaccination due to poor immunogenicity of carbohydrate antigens. In this article, a number of structure-modified GM3 antigen analogues were designed and chemically synthesized. The modified GM3 antigens were conjugated to protein carriers for vaccination. The vaccination results on mice show that the modification on the GM3 antigen could improve the efficiency of the vaccination, and in particular, two glycoconjugates (3-KLH and 8-KLH) elicited higher titers of anti-GM3 antibodies than the unmodified GM3-protein conjugate (2-KLH) did.
- Published
- 2015
46. Total Synthesis of a Hyperbranched N‐Linked Hexasaccharide Attached to ATCV‐1 Major Capsid Protein without Precedent.
- Author
-
Wang, Yong‐Shi, Wu, Yong, Xiong, De‐Cai, and Ye, Xin‐Shan
- Subjects
CAPSIDS ,PROTEINS ,GLYCANS ,CHLORELLA viruses ,GLYCOSYLATION - Abstract
Summary of main observation and conclusion: The N‐glycans attached to some chloroviruses comprise a hyperbranched core structure without precedent. We are interested in the chemical synthesis of the hexasaccharide attached to ATCV‐1 (Acanthocystis turfacea Chlorella virus 1) for its distinct structure. After exploring four routes, the target hexasaccharide 2 was successfully synthesized for the first time in overall 10% yield over 8 steps from thioglycoside building blocks. This synthetic protocol is characterized by the three‐component one‐pot glycosylation and the regioselective glycosylation reactions. The disclosed synthetic approach to this new type of N‐glycans will facilitate the in‐depth understanding of their biological functions. A highly branched hexasaccharide was successfully synthesized by the three‐component preactivation‐based one‐pot glycosylation and the regioselective glycosylation reactions for the first time. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
47. Iterative One-Pot Synthesis of Oligosaccharides
- Author
-
Xin-Shan Ye, Xuefei Huang, Lijun Huang, and Haisheng Wang
- Subjects
chemistry.chemical_compound ,Glycosylation ,chemistry ,One-pot synthesis ,Oligosaccharides ,Indicators and Reagents ,General Chemistry ,General Medicine ,Disaccharides ,Combinatorial chemistry ,Catalysis - Published
- 2004
48. ortho-Methylphenylthioglycosides as glycosyl building blocks for preactivation-based oligosaccharide synthesis
- Author
-
Peng Peng, Xin-Shan Ye, and De-Cai Xiong
- Subjects
chemistry.chemical_classification ,animal structures ,Glycosylation ,Molecular Structure ,Stereochemistry ,Organic Chemistry ,Oligosaccharides ,macromolecular substances ,General Medicine ,Oligosaccharide ,Biochemistry ,Coupling reaction ,Analytical Chemistry ,carbohydrates (lipids) ,chemistry.chemical_compound ,chemistry ,Thioglycosides ,lipids (amino acids, peptides, and proteins) ,Glycosyl ,Glycosyl donor ,Oligosaccharide synthesis ,Toluene - Abstract
Thioglycosides are widely used in orthogonal glycosylation, armed-disarmed chemoselective glycosylation, and preactivation-based glycosylation. Nevertheless, aglycon transfer occasionally occurred in the glycosylation process of thioglycosides. This problem was also encountered in preactivation-based reactions, which limited the applications of preactivation-based glycosylation to some extent. To tackle this problem, sterically hindered aglycon ortho-methylphenylthioglycosides were introduced as glycosyl building blocks. These thioglycosides prevented the aglycon transfer and enhanced the efficiency of glycosyl coupling reactions, especially in the reactions of disarmed donors with armed acceptors. Moreover, these thioglycosides were employed in preactivation-based one-pot oligosaccharide assembly.
- Published
- 2013
49. ChemInform Abstract: Preactivation: An Alternative Strategy in Stereoselective Glycosylation and Oligosaccharide Synthesis
- Author
-
Lin Yang, Qi Qin, and Xin-Shan Ye
- Subjects
chemistry.chemical_classification ,Chiral auxiliary ,Glycosylation ,Chemistry ,General Medicine ,Oligosaccharide ,Chemical synthesis ,Combinatorial chemistry ,carbohydrates (lipids) ,chemistry.chemical_compound ,lipids (amino acids, peptides, and proteins) ,Stereoselectivity ,Protecting group ,Oligosaccharide synthesis ,Alternative strategy - Abstract
The multifaceted biological importance of carbohydrates has made them very popular targets in modern synthetic chemistry. Great progress has been made in stereoselective glycosylation methods and the construction of complex oligosaccharides. This Focus Review highlights the versatile applications of preactivation strategies in stereoselective glycosylation and oligosaccharide synthesis. Recent advances in synthetic methods, such as 4,6-O-benzylidene-acetal-directed β-mannosylation, the 1,2-cis-glycosylation mediated by a chiral auxiliary, the use of an oxazolidinone or carbonate protecting group, and glycosylation with participating additives, are described. Various examples of sequential glycosylation based on preactivation protocols for efficient oligosaccharide assembly are also summarized.
- Published
- 2013
50. Correction: Light-driven highly efficient glycosylation reactions
- Author
-
Runze Mao, Xin-Shan Ye, Qin Li, Fan Guo, De-Cai Xiong, and Jinyou Duan
- Subjects
chemistry.chemical_compound ,Glycosylation ,chemistry ,Stereochemistry ,Organic Chemistry ,Light driven - Abstract
Correction for ‘Light-driven highly efficient glycosylation reactions’ by Run-Ze Mao et al., Org. Chem. Front., 2016, DOI: 10.1039/c6qo00021e.
- Published
- 2016
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