Synthesis of spacer-equipped di-, tri-, and the tetrasaccharide fragments of the deacetylated O-PS1 of Citrobacter gillenii O9a,9b, and a related pentasaccharide
摘要:
The title rhamnooligosaccharides [alpha-D-Rhap4NAc-(1 -> 3)-O(-D-Rhap4NAc-1-O-(CH2)(5)COOMe, alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc-(1 3)-alpha-D-Rhap4NAc-1-O-(CH2)(5)COOMe, alpha-D-Rhap4NAc-(1 -> 2)-alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc-1-O-(CH2)(5)COOMe, and alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc-(1-2)-(alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc(1 -> 3)-alpha-D-Rhap4NAc-1-O-(CH2)(5)COOMe] were synthesized in a stepwise fashion from 5-methoxycarbonylpentyl 4-azido-4, 6-dideoxy-2-O-benzyl-alpha-D-mannopyranoside and orthogonally protected 1-thioglycoside glycosyl donors. The amorphous, final products were fully characterized as corresponding per-O-acetyl derivatives. Published by Elsevier Ltd.
Molecular Recognition of <i>Brucella</i> A and M Antigens Dissected by Synthetic Oligosaccharide Glycoconjugates Leads to a Disaccharide Diagnostic for Brucellosis
作者:N. Vijaya Ganesh、Joanna M. Sadowska、Susmita Sarkar、Laurence Howells、John McGiven、David R. Bundle
DOI:10.1021/ja5081184
日期:2014.11.19
The cell wall O-polysaccharides of pathogenic Brucella species are homopolymers of the rare sugar 4,6-dideoxy-4-formamido-alpha-D-mannopyranose. Despite the apparent simplicity of the polysaccharide it appears to be a "block copolymer" composed of A and M polysaccharide sequences expressed as a single molecule. The simultaneous presence of both in the cell wall has complicated the understanding of the molecular recognition of these antigens by antibodies present in the serum of infected animals and humans and by monoclonal antibodies. Since presumptive diagnosis of brucellosis, a serious disease in domestic livestock, wild animals, and humans, is based on detection of these antibodies it is important to separate the two antigenic epitopes, one of which is also found in other bacteria. Chemical synthesis provides the only means to achieve this outcome. A series of six oligosaccharides from di to hexasaccharides 1-6 were synthesized and conjugated to proteins to provide glycoconjugate antigens and conjugate vaccines. These chemically defined antigens identified the M antigenic determinant and provided a structural basis for understanding the fine specificity of monoclonal and polyclonal antibodies that bind the M antigen. This resulted in the discovery of a disaccharide that shows considerable potential as an unambiguous diagnostic antigen for detecting brucellosis in humans and animals and two hexasaccharide conjugate vaccine candidates that produce high levels of O-polysaccharide specific antibodies in mice.
Synthetic glycoconjugates characterize the fine specificity of Brucella A and M monoclonal antibodies
作者:Satadru Sekhar Mandal、N. Vijaya Ganesh、Joanna M. Sadowska、David R. Bundle
DOI:10.1039/c7ob00445a
日期:——
The dominant cell wall antigen of Brucella bacteria is the O-polysaccharide component of the smooth lipopolysaccharide. Infection by various Brucella biovars causes abortions and infertility in a wide range of domestic and wild animals and debilitating disease in humans. Diagnosis relies on the detection of antibodies to the A and M antigens expressed in the O-polysaccharide. This molecule is a homopolymer
Synthesis of spacer-equipped di-, tri-, and the tetrasaccharide fragments of the deacetylated O-PS1 of Citrobacter gillenii O9a,9b, and a related pentasaccharide
作者:Rina Saksena、Anatoli Chernyak、Pavol Kováč
DOI:10.1016/j.carres.2008.03.037
日期:2008.7
The title rhamnooligosaccharides [alpha-D-Rhap4NAc-(1 -> 3)-O(-D-Rhap4NAc-1-O-(CH2)(5)COOMe, alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc-(1 3)-alpha-D-Rhap4NAc-1-O-(CH2)(5)COOMe, alpha-D-Rhap4NAc-(1 -> 2)-alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc-1-O-(CH2)(5)COOMe, and alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc-(1-2)-(alpha-D-Rhap4NAc-(1 -> 3)-alpha-D-Rhap4NAc(1 -> 3)-alpha-D-Rhap4NAc-1-O-(CH2)(5)COOMe] were synthesized in a stepwise fashion from 5-methoxycarbonylpentyl 4-azido-4, 6-dideoxy-2-O-benzyl-alpha-D-mannopyranoside and orthogonally protected 1-thioglycoside glycosyl donors. The amorphous, final products were fully characterized as corresponding per-O-acetyl derivatives. Published by Elsevier Ltd.