4-Amino-4,6-Dideoxyhexoses Isolated from Lipopolysaccharides of Escherichia coli

From the lipopolysaccharides of two Escherichia coli strains (serotypes O 7:K1:(L):H− and O10:K5 (L):H4) two unusual amino sugars were isolated. By sequential oxidation with periodate and hypoiodite, followed by identification of the reaction products, the aminosugars were characterized as 4-amino-4,6-dideoxy-d-hexoses. The chromatographic properties of the amino sugars and their N-acetyl derivatives were compared with those of authentic samples of free and N-acetylated 4-amino-4,6-dideoxy-d-glucose and 4-amino-4,6-dideoxy-d-galactose. On the basis of the results obtained the unknown amino sugars were tentatively identified as 4-amino-4,6-dideoxy-d-glucose (from the lipopoly-saccharide of E. coli O7:K1:(L):H−) and 4-amino-4,6-dideoxy-d-galactose (from the lipopolysaccharide of E. coli O10:K5(L):H4). This is the first time that 4-amino-4,6-dideoxy-d-galactose is described as a constituent of a polysaccharide.