title: Synthesis of a trisaccharide repeating unit of the O-antigen from Burkholderia anthina and its dimer.
abstract: A trisaccharide repeating unit of the O-antigen from Burkholderia anthina, α-L-Rha-(1→2)-α-L-Rha-(1→2)-β-D-Gal-O(CH2)3NH2 (1), and its dimer, α-L-Rha-(1→2)-α-L-Rha-(1→2)-α-D-Gal-(1→3)-α-L-Rha-(1→2)-α-L-Rha-(1→2)-β-D-Gal-O(CH2)3NH2 (2), were synthesized via a highly convergent and efficient assembly strategy. Sequential glycosylation of galactosyl acceptor 6 with rhamnosyl thioglycoside 7, followed by condensation of the resulting disaccharide acceptor 9 with rhamnosyl imidate donor 10, gave the title molecule 1 after global deprotection. The title hexasaccharide 2 was assembled in a convergent [2+2+2] manner, in which α-1,2-linked disaccharide 12 was initially obtained by the coupling reaction of disarmed thiorhamnoside acceptor 15 with armed thiogalactoside donor 14. Sequential glycosylation of disaccharide acceptor 9 with thioglycoside donors 12 and 13 afforded the target compound 2 after global deprotection.
authors.affiliation: National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250010, China.
authors.forename: Xueyun
authors.initials: X
authors.lastname: Geng
authors.affiliation: National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250010, China.
authors.forename: Lizhen
authors.initials: L
authors.lastname: Wang
authors.affiliation: National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250010, China. Electronic address: guofenggu@sdu.edu.cn.
authors.forename: Guofeng
authors.initials: G
authors.lastname: Gu
authors.affiliation: National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Jinan 250010, China. Electronic address: zwguo@sdu.edu.cn.
authors.forename: Zhongwu
authors.initials: Z
authors.lastname: Guo
mesh_terms: D019117:Burkholderia / Q000737:chemistry / Q000378:metabolism*; D002240:Carbohydrate Sequence; D006031:Glycosylation; D019081:O Antigens / Q000737:chemistry*; D055503:Protein Multimerization; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D019081:O Antigens; D014312:Trisaccharides
keywords: Burkholderia anthina; Carbohydrate vaccine; Lipopolysaccharide; O-Antigen; Synthesis