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

✍ Scribed by Wataru Kondo; Futoshi Nakazawa; Michiko Sato; Teiichiro Ito

• Publisher: Elsevier Science
• Year: 1983
• Tongue: English
• Weight: 501 KB
• Volume: 117
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(83)88081-1

✦ Synopsis

The antigenic polysaccharide produced by Eubacterium saburreum, strain T27, is a homoglycan composed of D-glycero-D-g&c@-heptose (Hep) residues having a nonasaccharide repeating-unit with the structure J+ 6)-[a-Hepf-( l-+4)]-/3-Hepp-( lj-+ 36)-[a-Hepf-(1+2), a-Hepf-(l-+4)]-P-Hepp-( l--+. The polysaccharide contains acetyl groups linked to O-2 (except to the 2,4,6-linked heptopyranosyl residue), O-3 and O-7 0, 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.

RESULTS AND DISCUSSION

Acid hydrolysis of the antigenic polysaccharide gave two compounds, in the ratio of 47:3. The first, isolated by p.c., was identified as D-glycero-D-galacto-heptose. The mass spectrum of its per-0-trimethylsilylalditol derivative showed that it was derived from a heptose. The 'H-n.m.r. spectrum of the sugar was indistinguishable from that of an authentic sample', and its optical rotation, [cr]: t-56" (c 0008~h215/83