Most bacterial cell surface glycans are structurally unique, and have been considered as ideal target molecules for the developments of detection and diagnosis techniques, as well as vaccines. Chemical synthesis has b...Most bacterial cell surface glycans are structurally unique, and have been considered as ideal target molecules for the developments of detection and diagnosis techniques, as well as vaccines. Chemical synthesis has been a promising approach to prepare well-defined oligosaccharides, facilitating the structure-activity relationship exploration and biomedical applications of bacterial glycans. L-Galactosaminuronic acid is a rare sugar that has been only found in cell surface glycans of gram-negative bacteria. Here, an orthogonally protected L-galactosaminuronic acid building block was designed and chemically synthesized. A synthetic strategy based on glycal addition and TEMPO/BAIB-mediated C6 oxidation served well for the transformation of commercial L-galactose to the corresponding L-galactosaminuronic acid. Notably, the C6 oxidation of the allyl glycoside was more efficient than that of the selenoglycoside. In addition, a balance between the formation of allyl glycoside and the recovery of selenoglycoside was essential to improve efficiency of the NIS/TfOH-catalyzed allylation. This synthetically useful L-galactosaminuronic acid building block will provide a basis for the syntheses of complex bacterial glycans.展开更多
Bacterial surface glycans perform a diverse and important set of biological roles,and have been widely used in the treatment of bacterial infectious diseases.The majority of bacterial surface glycans are decorated wit...Bacterial surface glycans perform a diverse and important set of biological roles,and have been widely used in the treatment of bacterial infectious diseases.The majority of bacterial surface glycans are decorated with diverse rare functional groups,including amido,acetamidino,carboxamido and pyruvate groups.These functional groups are thought to be important constituents for the biological activities of glycans.Chemical synthesis of glycans bearing these functional groups or their variants is essential for the investigation of structure-activity relationships by a medicinal chemistry approach.To date,a broad choice of synthetic methods is available for targeting the different rare functional groups in bacterial surface glycans.This article reviews the structures of naturally occurring rare functional groups in bacterial surface glycans,and the chemical methods used for installation of these groups.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22077052,21877052,21907039)the China Postdoctoral Science Foundation(2020M681487)+5 种基金the National Key R&D Program of China(2020YFA0908304)the Natural Science Foundation of Jiangsu Province(BK20180030,BK20190575)the National First-class Discipline Program of Light Industry Technology and Engineering(LITE2018-14)the 111 Project(111-2-06)the Open Project of Key Laboratory of Carbohydrate Chemistry and Biotechnology(Jiangnan University),Ministry of Education(KLCCB-KF202005)the Natural Science Foundation of Xuzhou(KC19154).
文摘Most bacterial cell surface glycans are structurally unique, and have been considered as ideal target molecules for the developments of detection and diagnosis techniques, as well as vaccines. Chemical synthesis has been a promising approach to prepare well-defined oligosaccharides, facilitating the structure-activity relationship exploration and biomedical applications of bacterial glycans. L-Galactosaminuronic acid is a rare sugar that has been only found in cell surface glycans of gram-negative bacteria. Here, an orthogonally protected L-galactosaminuronic acid building block was designed and chemically synthesized. A synthetic strategy based on glycal addition and TEMPO/BAIB-mediated C6 oxidation served well for the transformation of commercial L-galactose to the corresponding L-galactosaminuronic acid. Notably, the C6 oxidation of the allyl glycoside was more efficient than that of the selenoglycoside. In addition, a balance between the formation of allyl glycoside and the recovery of selenoglycoside was essential to improve efficiency of the NIS/TfOH-catalyzed allylation. This synthetically useful L-galactosaminuronic acid building block will provide a basis for the syntheses of complex bacterial glycans.
基金This work was supported by the National Natural Science Foundation of China(Nos.22077052,21877052,21907039,22107037)China Postdoctoral Science Foundation(2020M681487,2021M691279)+4 种基金the National Key R&D Program of China(2020YFA0908304)the Natural Science Foundation of Jiangsu Province(BK20180030,BK20190575)the National First-class Discipline Program of Light Industry Technology and Engineering(LITE2018-14)the 111 Project(111-2-06)the Open Project of Key Laboratory of Carbohydrate Chemistry and Biotechnology(Jiangnan University),Ministry of Education(KLCCB-KF202005).
文摘Bacterial surface glycans perform a diverse and important set of biological roles,and have been widely used in the treatment of bacterial infectious diseases.The majority of bacterial surface glycans are decorated with diverse rare functional groups,including amido,acetamidino,carboxamido and pyruvate groups.These functional groups are thought to be important constituents for the biological activities of glycans.Chemical synthesis of glycans bearing these functional groups or their variants is essential for the investigation of structure-activity relationships by a medicinal chemistry approach.To date,a broad choice of synthetic methods is available for targeting the different rare functional groups in bacterial surface glycans.This article reviews the structures of naturally occurring rare functional groups in bacterial surface glycans,and the chemical methods used for installation of these groups.
