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A PhPO-modulated β-selective Kdo glycosidation approach is developed for the stereoselective synthesis of β-Kdo glycosides. With the readily available per--acetylated Kdo ynenoate as the donor, the glycosylation with a series of alcohols in the presence of PhPAuOTf and PhPO in toluene at low temperatures afforded the desired Kdo glycosides with good to excellent β-selectivities. Furthermore, the PhPO-modulated approach was effectively applied to the synthesis of β-(2→4)- and β-(2→8)-linked Kdo-Kdo disaccharides for further biological studies.
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http://dx.doi.org/10.1021/acs.orglett.4c04193 | DOI Listing |
Org Lett
December 2024
Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
A PhPO-modulated β-selective Kdo glycosidation approach is developed for the stereoselective synthesis of β-Kdo glycosides. With the readily available per--acetylated Kdo ynenoate as the donor, the glycosylation with a series of alcohols in the presence of PhPAuOTf and PhPO in toluene at low temperatures afforded the desired Kdo glycosides with good to excellent β-selectivities. Furthermore, the PhPO-modulated approach was effectively applied to the synthesis of β-(2→4)- and β-(2→8)-linked Kdo-Kdo disaccharides for further biological studies.
View Article and Find Full Text PDFJ Phys Chem B
August 2024
State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan 430062, People's Republic of China.
Glycosyltransferases (GTs) are pivotal enzymes involved in glycosidic bond synthesis, which can lead to either retention or inversion of the glycosyl moiety's anomeric configuration. However, the catalytic mechanism for retaining GTs remains a subject of controversy. In this study, we employ MD and QM/MM metadynamics to investigate the double-displacement catalytic mechanism of the retaining β-Kdo transferase WbbB.
View Article and Find Full Text PDFOrg Lett
March 2024
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
A chemical synthesis of a unique nanosaccharide fragment from lipopolysaccharide was achieved via a convergent glycosylation method. Challenges involved in the synthesis include the highly stereoselective construction of β-3-deoxy-d--oct-2-ulosonic acid (Kdo) and two 1,2--glycosidic linkages, as well as the formation of a branched 2,7-disubstituted heptose subunit. Hydrogen-bond mediated aglycone delivery strategy and benzoyl-directing remote participation effect were employed, respectively, for the efficient generation of the desired β-Kdo glycoside and 1,2--α-l-fucoside/d-glucoside.
View Article and Find Full Text PDFOrg Biomol Chem
March 2024
Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism, Shanghai Key Laboratory of New Drug Design, Engineering Research Center of Pharmaceutical Process Chemistry, Ministry of Education, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
A DMF-modulated glycosylation approach for the stereoselective synthesis of α-Kdo glycosides with readily accessible peracetylated Kdo ynenoate as a donor was described. By utilizing this approach, we completed the synthesis of various linkage types of Kdo-Kdo disaccharides and the α-Kdo-containing protected trisaccharide variant relevant to the lipopolysaccharide of strain Nine Mile.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2024
State Key Laboratory of Natural and Biomimetic Drugs, Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China.
3-Deoxy-d-manno-oct-2-ulosonic acid (Kdo) is an eight-carbon monosaccharide found widely in bacterial lipopolysaccharides (LPSs) and capsule polysaccharides (CPSs). We developed an indirect method for the stereoselective synthesis of α-Kdo glycosides with a C3-p-tolylthio-substituted Kdo phosphite donor. The presence of the p-tolylthio group enhanced the reactivity, suppressed the formation of elimination by-products (2,3-enes), and provided complete α-stereocontrol.
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