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The investigation of the inclusion complexes obtained with heptakis-(2,6-di- O -methyl)- β -cyclodextrin (DM-β-Cdx) or heptakis-(2,3,6-tri- O -methyl)- β -cyclodextrin (PM-β-Cdx) and either 1-anilinonaphthalene-8-sulfonate (ANS) or2- p -toluidinylnaphthalene-6-sulfonate (TNS) was carried out by means of ionspray mass spectrometry, both in the positive and in the negative ion mode. All the data collected showed that the heptakis-(2,3,6-tri- O -methyl)- β -cyclodextrin interacted to a very little extent with TNS and not at all with ANS. On the contrary, heptakis-(2,6-di- O -methyl)- β -cyclodextrin formed complexes with both aromatic molecules showing a more effective interaction with TNS. Small variations in the number of methoxy substituents in the DM-β-Cdx molecule did not affect the complexation behaviour significantly. The spectra recorded at different orifice potentials indicated that the complex of heptakis-(2,6-di- O -methyl)- β -cyclodextrin with TNS is more stable than the one formed with ANS. These results agreed on one hand with the conformations of both the heptakis-(2,6-di- O -methyl)- β -cyclodextrin and heptakis-(2,3,6-tri- O -methyl)- β -cyclodextrin, established by X-ray diffraction studies, and, on the other hand, with the different complexation behaviour of the guest aromatic molecules due to their own geometry.

In this work, we carried out the elucidation of a novel lipooligosaccharide (LOS) from a clinical strain of the most virulent strain of the Burkholderia cepacia complex, which was of B. cenocepacia ET-12 epidemic strain lineage. The strain was isolated from a cystic fibrosis patient who had successfully undergone lung transplantation. This molecule presents some specific chemical differences when compared to the LOS reported so far from other B. cenocepacia ET-12 clones. The new endotoxin was also tested as a cytokine enhancer on human myelomonocytic U937 cells. Lipopolysaccharides are the main virulence factors of Gram-negative bacteria, and since they are exposed to the extracellular space, they are deeply involved in bacterial adaptation to the host environment. The characterisation of structural motifs present in these molecules is essential to the comprehension of the persistence/survival mechanisms and inflammatory potential of these bacteria.

Homoditopic building blocks 1, featuring two π-rich cone-like calix[5]arene moieties connected at their narrow rims by a rigid o-, m-, or p-xylyl spacer in a centrosymmetric divergent arrangement, show a remarkable tendency to spontaneously and reversibly self-assemble with the complementary homoditopic α,ω-alkanediyldiammonium dipicrate guest salts C8−C12·2Pic through iterative intermolecular inclusion events, forming supramolecular assemblies whose composition and dynamics strongly depend upon the length of the connector, the geometry of the spacer, as well as the concentration and/or molar ratios between the two components. 1H NMR spectroscopy and ESI-MS studies of 1/Cn·2Pic modular homoditopic pairs support the formation of discrete (bis)-endo-cavity assemblies with the shorter C8 and C9 connectors, and/or (poly)capsular assemblies with the longer C10−C12 components under appropriate concentrations and molar ratios (50 mM equimolar solutions). 1H NMR titration experiments and diffusion NMR studies pro...

Two O-chain structures were identified after acid hydrolysis of the lipopolysaccharide fraction of Agrobacterium radiobacter (type strain). The first is constituted by the linear tetrasaccharide repeating unit [2)-α-L-Rhap-(1→3)-α-L-Rhap-(1→3)-α-L-Rhap-(1→2)-α-L-Rhap-(1→]n and the second by the (1→2)-branched repeating unit α-D-Manp-(1→2)−[3)-α-D-Fucp-(1→3)-α-D-Fucp-(1→]n.The two structures were determined mainly by 1D- and 2D NMR spectroscopy together with chemical-degradation methods. A detailed analysis of the NOESY spectrum, supported by molecular dynamics calculations, suggested that some unexpected NOEs were due to the sum of many small dipolar effects, whose identification was possible only by considering the 3D structure of an O-chain oligosaccharide bigger than the repeating unit. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Despite intense efforts to increase vaccine coverage, measles virus (MV) still causes significant morbidity and mortality in the world sometimes as a results of severe, chronic and lethal diseases. In an effort to develop therapies to supplement immunization strategies a number of 1-oxo-2-[[(1E)-phenylmethylene]amino]-1,2-dihydroisoquinoline-4-carboxylic acid derivatives were synthesized and evaluated for anti-measles activity. The substituents on the aromatic ring were chosen in order to evaluate the influence of electron-withdrawing or electron-donating effects on the electronic density of the aromatic moiety. We also evaluated the introduction of a vinyl chain between the exocyclic nitrogen and phenyl moiety. The biological results allow to outline some preliminary considerations on structure-activity relationship.