4-O-(2-AMINO-2-DEOXY-ALPHA-D-GLUCOPYRANOSYL)-3-DEOXY-D-MANNO-2-OCTULOSONIC ACID, A CONSTITUENT OF LIPOPOLYSACCHARIDES OF THE GENUS PECTINATUS

A disaccharide containing GlcN and 3-deoxy-D-manno-2-octulosonic acid (Kdo) was detected after acidic methanolysis and peracetylation of hydrofluoric-acid-treated smooth-type and rough-type lipopolysaccharide of Pectinatus cerevisiiphilus and Pectinatus frisingensis, which are strictly anaerobic bacteria capable of growing in packaged beer. The disaccharide was also found in alkali-treated lipopolysaccharide, but was not directly detectable from intact lipopolysaccharide. This suggested that the disaccharide carried a phosphate residue. The position of this phosphate was shown, by GLC/MS of appropriately degraded and derivatized samples, to be O6 of the GlcN. Methylation analysis of the purified disaccharide revealed that GlcN was linked to position 4 of Kdo. The acetylated derivative of the disaccharide was isolated in pure form, and, by H-1-NMR and C-13-NMR spectroscopy, it was confirmed to possess the structure alpha-D-GlcpN-(1'-->4)-Kdo. In the lipopolysaccharide the amino group of GlcN is free.