Facile synthesis of arabinomannose penta- and decasaccharide fragments of the lipoarabinomannan of the equine pathogen, Rhodococcus equi
作者:Zuchao Ma、Jianjun Zhang、Fanzuo Kong
DOI:10.1016/j.carres.2004.04.012
日期:2004.7
Pentasaccharide repeating unit 20 of the lipoarabinomannan from the equine pathogen, Rhodococcus equi, and its dimer 31, were synthesized. The pentasaccharide was obtained by assembling a benzoylated 2,6-branched mannosyl trisaccharide acceptor 13 with a free hydroxyl group at C-2' of the mannose residue attached to the core mannose residue by (1 --> 6)-linkage, followed by coupling with 2,3,5-tri-O-benzoyl-alpha-D-arabinofuranosyl-(1 --> 2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate (18), and by deacylation. Meanwhile, the decamer 31 was obtained by firstly preparing a benzoylated mannose (1 --> 6)-linked tetra-saccharide backbone 26 with 2-, 2"-O-ClAc, and 2'-, 2"'-O-Ac groups, respectively, then by dechloroacetylation and subsequent condensation with perbenzoylated trichloroacetimidate, and then by deacetylation and subsequent coupling with 18, and finally, by deacylation. (C) 2004 Elsevier Ltd. All rights reserved.