The structure of the lipopolysaccharide from Salmonella friedenau TI form has been investigated. The TI-specific chains are composed of almost equal amounts of P-n-ribofuranose and P-D-galactofuranose residues. The former are linked to the 2-position, the latter to the 3-position or, to a smaller extent, to the 6-position. A low percentage of branching, through /3-D-galactofuranose residues, substituted in the 3-and 6-position, is demonstrated. The core region of the T I lipopolysaccharide seems to have the same general structure as that of other Salmonella lipopolysaccharides.Two groups of Salmonella mutants have been recognized, both of which are devoid of the 0 specificity of the wild type: (a) The various classes of R mutants have been shown to be defective in one (or several) step(s) in the biosynthesis of the cell wall lipopolysaccharides (0 antigens), and, as a consequence, the respective R antigens, which exhibit R specificities, represent incomplete lipopolysaccharides, lacking the 0-specific side chains only or, in addition, smaller or larger parts of the core polysaccharide [I]. (b) T I Mutants, first identifiedby Kauffmann in 1956 [a] are characterized by the TI specificity. Genetic and biochemical investigations have shown that T I mutants synthesize a complete lipopolysaccharide, in which, however, the 0-specific side chains are replaced by a Ti-specific side chain, which is common to all T i mutants irrespective from which Salmonella serotype they are derived [3].In a previous publication [4] it was shown that T1 lipopolysaccharides contain the 5 basal sugars, which constitute the common core polysaccharide of Salmonella S form lipopolysaccharides, namely KDO, heptose, glucose, galactose and glucosamine. I n addition, T I lipopolysaccharides contain large amounts of D-ribose and D-galactose. The sugars constituting the 0-specific side chains of the parent wild type are absent. Ribose and galactose were found in the specific precipitates formed on addition of TI antiserum to T I lipopolysaccharides. On treatment of T I lipopolysaccharides with mild acid, 'Freeman' degraded T I polysaccharide was obtained in which ribose and galactose were present in the form of non-dialysable polymers.I n the past, structural investigations on lipopolysaccharides were performed mainly through chemical Unusual Abbreviation. KDO, and immunochemical analysis of fragments obtained by partial hydrolysis [5]. This procedure, besides being quite time-consuming and liable to misinterpretations, generally leads to the identification of only parts of the structure of these most complicated heteropolysaccharides, though, without doubt, these studies have immensely increased our knowledge on the immunochemistry of bacterial antigens.The recent evaluation of new procedures for the identification of partially methylated sugars, as they are obtained on hydrolysis of methylated polysaccharides, provide a new and independent comparatively quick way for structural analyses of polysaccharides. I n this procedure, methylated sugars ar...

Lipopolysaccharides of Salmonella T1 forms contain ribose and galactose both present as furanosides. Mild periodate oxidation of the T I lipopolysaccharide followed by treatment with alkali resulted in the formation of a main fragment which was identified as poly-ribose linked to the core polysaccharide. Poly-ribose was also identsed as a degradation product of periodate oxidized Tl lipopolysaccharide which had been treated with mild acid. Another fragment formed under these conditions was identified as being derived from -6-Galf-l,3-Galf-1,3-Galf-l,6-Galf-l-. These results indicated that the T1-specific polysaccharide of Tl lipopolysaccharides contain poly-ribose and poly-galactose regions. Galactose-trisaccharide units may be present as repeating units of a poly-galactose chain.Salmonella T1 forms, which were identified by MATERIAL AND METHODS Kauffmann in 1956 [l], contain a lipopolysaccharide which is characterized by the presence of D-ribose and D-galaCtOSe residues [2] both linked as furanosides. It was found by methylation analysis thatribose is linked at position 2, and galactose a t positions 3, 6, or 3 and 6. These results were confirmed by analysis of the T1 lipopolysaccharide after periodate oxidation and reduction. As expected) ribose and part of the galactose were resistant to periodate oxidation, while most of the galactose was degraded either to arabinose or to threitol. All furanosides occur in a ,!?-linkage in the lipopolysaccharide 131.I n order to obtain more information on the structure of T1 lipopolysaccharides, two degradation reactions were performed. Firstly, T1 lipopolysaccharide was oxidized with periodate under mild conditions) whereby the 3-substituted galactofuranosides were converted into 3-substituted arabinoaldehydes. The oxidized lipopolysaccharide was then treated with alkali. This leads t o the elimination of substituents present in p-position of the aldehyde groups of arabinoaldehyde (,!?-elimination reaction [a], see formula I). Secondly) periodate-oxidized and borohydride-reduced T1 lipopolysaccharide was hydrolyzed under mild acid conditions, whereby the linkages of degraded 6-substituted galactose residues to the neighbour sugar were cleaved (Smith degradation reaction 151). The isolation and identification of fragments formed after these treatments indicate that the TI-specific region of T l lipopolysaccharides contains chains of poly-ribose and trisaccharide units of galactose. The latter may be present as repeating units of a poly-galactose chain. Bacteria and Lipopolysaccharides Salmonella friedenau

LIPOPOLYSACCHARIDES OF SALMONELLA T MUTANTS the chemistry and immunochemistry of lipopolysaccharide preparations from several T-form organisms. MATERIALS AND METHODS Microorganisms. S. typhimurium TI, S. paratyphi B Ti, and S. bareilly T2 were grown by F. Kauffmann, Statens Seruminstitut, Copenhagen, Denmark (26); S. friedenau Ti and S. dessau Ti were grown by J. Schlosshardt, Zentrallaboratorium f.