In:
Pure and Applied Chemistry, Walter de Gruyter GmbH, Vol. 84, No. 1 ( 2011-11-19), p. 11-21
Abstract:
Attachment of 4-amino-4-deoxy-L-arabinose (Ara4N) to phosphates or sugar hydroxyl groups of lipopolysaccharide (LPS) contributes to bacterial resistance against common antibiotics. For a detailed study of antigenic properties and binding interactions, Ara4N-containing inner-core ligands related to Burkholderia and Proteus LPS have been synthesized in good yields. Glycosylation at position 8 of allyl glycosides of oct-2-ulosonic acids (Ko, Kdo) has been accomplished using an N -phenyltrifluoroacetimidate 4-azido-4-deoxy-L-arabinosyl glycosyl donor followed by azide reduction and global deprotection. The β-L-Ara4N-(1 → 8)-α-Kdo disaccharide was further extended into the branched β-L-Ara4N-(1 → 8)[α-Kdo-(2 → 4)]-α-Kdo trisaccharide via a regioselective glycosylation of a protected triol intermediate. Synthesis of Ara4N-modified lipid A part structure occurring in the LPS of Burkholderia , Pseudomonas , and Klebsiellla strains was accomplished using the H -phosphonate approach. The stereocontrolled assembly of the phosphodiester linkage connecting glycosidic centers of two aminosugars was elaborated employing an anomeric H -phosphonate of cyclic silyl-ether protected 4-azido-4-deoxy-β-L-arabinose, which was coupled to the hemiacetal of the lipid A GlcN-disaccharide backbone. Conditions for global deprotection, which warrant the integrity of “double anomeric” phosphodiester linkage, were successfully developed. Introduction of thiol-terminated spacer at the synthetic ligands allows both coupling to bovine serum albumin (BSA) and immobilization on gold nanoparticles as well as generation of glycoarrays.
Type of Medium:
Online Resource
ISSN:
1365-3075
,
0033-4545
DOI:
10.1351/PAC-CON-11-08-01
Language:
Unknown
Publisher:
Walter de Gruyter GmbH
Publication Date:
2011
detail.hit.zdb_id:
1514-3
detail.hit.zdb_id:
2022101-0
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