Structural studies of a polysaccharide (S-88) elaborated by Pseudomonas ATCC 31554

The structure of the extracellular polysaccharide elaborated by Pseudomonas ATCC 31554 has been investigated, methylation analyses, specific degradations, and 1H-n.m.r. spectroscopy being the main methods used. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units with the structure: ----3)-beta-D-Glcp-(1----4)-beta-D-GlcpA-(1----4)-beta-D-Glcp- (1----4)-alpha-L-[Rha or Man]-(1---- 3 increases 1 alpha-L-Rha. An unusual feature is that a sugar residue in the chain may be either L-rhamnose or L-mannose. The polysaccharide also contains O-acetyl groups (approximately 5%) which have not been located.