Twelve motile Aeromonas strains have been examined with respect to the hexose and heptose monosaccharide residures present in the core region of their cell wall lipopolysaccharides. These strains were divided into three distinctly separate groups on the basis of the various combinations of hexose and heptose residues. The assignment of a strain to any one of the three groups furnishes a distribution which is substantially the same as that recently reported in a computerbased numerical analysis. All strains tested which were previoulsy named A. liquefaciens fall into the same group.
Electrospray mass spectrometry of a series of organotin compounds in solutions of methanol are reported. Low energy collision‒induced dissociation MS/MS analysis of diagnostic precursor ions confirmed the characteristic fingerprint patterns obtained in the conventional electrospray spectra and proved to be a specific and very sensitive method for quantification of the (R3Sn)2O and the series of RnSnX4–ncompounds in environmental matrices. Concentrations of butyltin compounds (TBTX, DBTX2and MBTX3) in sediment reference materials PACS-1 and PACS-2 and butyltin and phenyltin compounds (TBTX, DBTX2, MBTX3, TPTX, DPTX2and DPTX3) in Quasimeme II biota reference material (QSP001BT) were determined. The organotin compounds were extracted from the reference materials with 1-butanol followed by dilution with methanol containing 1 mM ammonium acetate. The extracts were introduced directly into the electrospray source by a continuous flow of MeOH : H2O (60 :40). Quantitation of TBTX, DBTX2, TPTX, DPTX2and DPTX3was achieved by low energy CID tandem mass spectrometry using the Multiple Reaction Monitoring (MRM) analysis with the appropriate MS/MS transitions (positive ion electrospray ionization). Quantitation of MBTX3was achieved using a negative ion electrospray CID tandem mass spectrometry method. For all samples quantitation was achieved by use of the method of standard addition, relative extraction recoveries were determined spiking with internal standards of mono‒, di‒ and triorganotin compounds separately to different samples.
The structure of the core oligosaccharide of Vibrio ordalii has been investigated. The studies involved the use of nuclear magnetic resonance, methylation analysis, partial hydrolysis with hydrochloric acid, nitrous acid deamination, partial hydrolysis with sulfuric acid, Smith degradation, and oxidation with chromium trioxide. As a result of these studies the following structure is proposed.[Formula: see text]
Conjugation of simple ketoses (such as 3-deoxy-~-manno-2-octu~osonic acid and N-acetylneuraminic acid) and of various 0-specific polysaccharides (from Aerornonas hydrophila and Aeromonas salmonicida) to the bifunctional spacer 2,6-hexanediamine, was achieved by reductive amination. The saccharide -1-(ti-amino)-hexane alkyamines obtained were converted into the corresponding isothiocyanate derivatives and coupled to the free c-amino group of lysine residues of the protein carrier bovine serum albumin. In similar manner, the aldehyde group introduced by selective periodate oxidation into the partially 0-deacylated lipopolysaccharide of Vibrio anguillarum was conjugated to 1,6-hexanediamine, converted into the corresponding isothiocyanate and covalently attached to bovine serum albumin.During the past decade, artificial glycoconjugates or neoglycoproteins, obtaincd by covalent attachment of polysaccharide to protein, have been extensively used for antibody -polysaccharide interactions [l] and found to be of great utility as vaccines against encapsulated bacteria [2].Numerous methods, each with their own merits and purposes, have been developed for the synthesis of glycoconjugates [3]. Most of these studies have generally resorted to the use of naturally occurring bacterial oligo-and polysaccharides or chemically synthesized carbohydrate haptens which mimic the natural saccharide sequences of the carbohydrate portion of the conjugate. One method that is both simple and effective is the direct covalent attachment of reducing carbohydrates to the amino groups of proteins by reductive amination using sodium cyanoborohydride [4, 51. A major disadvantage of this method is the opening of the ring structure of the terminal reducing sugar to generate an acyclic amine which, in certain cases, could be detrimental to the biological specificities of the glycoconjugate [6]. However, this disadvantage is of no importance if the haptenic saccharide is large, as in the case of bacterial polysaccharide [7]. Another drawback to this method is that it is not possible to conjugate oligosaccharides having reducing ketose residues, such as the terminal 3-deoxy-~-manno-2-octulosonk acid (dOclA), to proteins [8]. This is consistent with the fact that a successful reductive amination attachment of oligosaccharides containing terminal dOclA residues to proteins can be achieved only if a functionalized spacer molecule is introduced at the ketonic carbonyl group of dOclA [8, 91. This paper presents a new method for coupling different 0-specific polysaccharides and a partially 0-deacylated oxidized lipopolysaccharide of representative species of the Vibrionaceae family to the lysine residues of the carrier protein bovine serum albumin. The method presented here is based on the attachment of the new spacer (or bridging arm) 1,6-hexanediamine, by reductive amination, to the ketonic carbonyl group of the only dOclA residue of the coreoligosaccharide portion [lo, 111 of the native 0-specific polysaccharides of Aeromonas hydrophila and Aeromonas s...
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