Structural studies of the antigenic polysaccharide of Eubacterium saburreum, strain T27.

The antigenic polysaccharide produced by Eubacterium saburreum, strain T27, is a homoglycan composed of D-glycero-D-galacto-heptose (Hep) residues having a nonasaccharide repeating-unit with the structure (leads to 6)-[alpha-Hepf-(1 leads to 4)]-beta-Hepp-(1) leads to (3)6)-[alpha-Hepf-(1 leads to 2), alpha-Hepf-(1 leads to 4)]-beta-Hepp-(1 leads to. The polysaccharide contains acetyl groups linked to O-2 (except to the 2,4,6-linked heptopyranosyl residue), O-3 and O-7 of part of both heptopyranosyl and heptofuranosyl residues. The assignment of an acetyl group at O-3 of part of the terminal heptofuranosyl and 4,6-linked heptopyranosyl groups is tentative.