Biochemical Studies on Lipopolysaccharides of Salmonella R Mutants

From Salmonella R lipopolysaccharides of the chemotypes Rc, Rd 1 , and Rd 2 oligosaccharides were prepared and their structure studied by the following methods: quantitative sugar analyses; periodate oxidation followed by borohydride reduction in order to transform the l ‐glycero‐ d ‐mannose residues into d ‐mannose residues; methylation of original and transformed oligosaccharides, methanolysis and gas chromatographic identification of the methylated heptoses or mannoses; the action of glycosidases; serological tests. The results of the study are in agreement with the formulae given below for the different oligosaccharides. The anomeric form of the glucose unit linked to heptose, as well as that part of the oligosaccharides which contains the 2‐keto‐3‐deoxy‐octonate residues KDO remain uncertain. Chemotypes Rd 2 : Heptose p α 1→KDO x ; Rd 1 : Heptose p α 1→3 Heptose p α 1→KDO x ; Re: Glucose 1→3 Heptose p α 1→3 Heptose p α 1→KDO x .