Anette Svensson

Design and evaluation of pilicides: potential novel antibacterial agents directed against uropathogenic Escherichia coli.

Design and evaluation of Pilicides : Potential novel antibacterial agents directed against Uropathogenic Escherichia coli

Use of 19F NMR spectroscopy to evaluate reactions in solid phase organic synthesis

Abstract Gel-phase 19F NMR spectroscopy has been used to characterize products from a variety of reactions of fluorinated aromatics linked to a TentaGel resin. High quality spectra were obtained in a few minutes using an ordinary NMR spectrometer, and the 19F chemical shifts of the support-bound compounds closely matched those of soluble references. In addition, substantial chemical shift differences were obtained for almost all of the synthetic transformations, illustrating the potential of 19F NMR for rapid monitoring of reactions in solid-phase organic synthesis.

Fluorinated linkers for monitoring solid-phase synthesis using gel-phase 19F NMR spectroscopy

Abstract Three fluorinated linkers which are analogues of linkers commonly used in solid-phase peptide synthesis have been prepared. Using 19F NMR spectroscopy, the fluorine atom of the linker allowed monitoring of several transformations in the solid-phase synthesis of a peptoid having a coumarin moiety. Especially, attachment of the linker to the solid phase, coupling of the first building block to the linker and cleavage of the product were efficiently monitored and optimised.

Interactions of α-, β- and γ-cyclodextrin with bicyclo[2.2.2]octane-1,4-derivatives in aqueous solution and in the gas phase

Binding of 1,4-di-R-bicyclo[2.2.2]octanes [R = OH (bic), Me (bim)] to α-, β- and γ-cyclodextrin (α-CD, β-CD and γ-CD) in the gas phase and in aqueous solution have been studied by force-field computations and by isothermal titration microcalorimetry, respectively. For bic, a 1:1 stoichiometric model was assumed in the treatment of the microcalorimetric data. In the gas phase, for both α-CD and β-CD, bim penetrates less deeply into the cavity than bic. The shallow penetration of bim allows a second α- cyclodextrin molecule to bind, in agreement with the 1:2 complex observed in a solvent mixture by NMR measurements, as reported earlier. In aqueous solution, β-CD binds to bic with moderate Gibbs energy change, a large and negative heat capacity change and compensating temperature dependences for the enthalpy and the entropy changes. α-CD and γ-CD bind weakly to bic in solution, whilst large binding energies were obtained for both guests for the gas-phase interactions with α-CD and β-CD.

An Efficient Protocol for the Epoxidation of Acid-and Acid/Base-Sensitive Alkenes With m-Chloroperoxybenzoic Acid

Abstract An efficient protocol for the epoxidation of acid-and acid/base-sensitive alkenes with m-chloroperoxybenzoic acid and using 2,6-di-tert-butylpyridine as a buffer is described.

Structure and Dynamic Stability of Cyclodextrin Inclusion Complexes With 1, 4-Disubstituted Bicyclo-[2.2.2]Octanes

The properties of inclusion complexes of 1,4-di-R-bicyclo[2.2.2]octaves (R = H (1), Me (2), Cl (3), Br (4), and OH (5)) with cyclodextrins have been studied by NMR, microcalorimetry, and force-field computations. The compounds2 and3 (but not the other compounds) give dynamically stable 1:2 guest-host complexes with α-cyclodextrin. Microcalorimetry of5 in water indicates a moderately strong 1:1 complex with β- but weak complexes with α- or γ-cyclodextrin. The behaviour depends on the subtle interplay size, polarity, hydrophobicity and type of solvent.

Design, Synthesis and Biological Evaluation of Pilicides: Inhibitors of Pilus Assembly in Pathogenic Bacteria

Due to bacterial resistance, there is a constant struggle to get new treatments for bacterial diseases. A wide range of pathogenic gram-negative bacteria such as E. coli, K. pneumonia and Y. Pestis assembles hair-like adhesive protein filaments called pili on their surfaces. These organelles mediate attachment to the host-cell during microbial invasion. The stabilization and transportation of pilus subunits through the periplasmic compartment by a periplasmic chaperone is crucial in pilus assembly. Inhibition of the chaperone/subunit complex, thus preventing pilus assembly, appears to be a good target for development of a new antibacterial drug.