Maryse Bourdonneau

Preparation and sorption properties of a β‐cyclodextrin‐linked chitosan derivative

(3-Cyclodextrin (β-CD) was coupled to chitosan by the intermediate of its monochlorotriazinyl derivative, called βW7MCT, so that a chitosan derivative bearing cyclodextrin was obtained. Because the average degree of substitution of the cyclodextrin derivative was 2.8, the reaction yielded crosslinked insoluble products. The structure of these materials has been investigated by high-resolution magic-angle spinning (HRMAS) with gradients. For the first time, HRMAS spectra of chitosan polymers containing β-CD were obtained. This NMR technique produced one- and two-dimensional well-resolved solid-state spectra. These data confirm the proposed structure. Decontamination of waters containing textile dyes were carried out with the crosslinked derivatives. These tests showed that the new chitosan derivatives are characterized by a rate of sorption and a global efficiency superior to that of the parent chitosan polymer and of the well-known cyclodextrin-epichlorohydrin gels.

Solid-state NMR characterization of cyclomaltoheptaose (β-cyclodextrin) polymers using high-resolution magic angle spinning with gradients

Solid-state nuclear magnetic resonance (NMR) techniques were used to characterize cyclomaltoheptaose (β-cyclodextrin, β-CD) polymers. These insoluble materials have been investigated by cross-polarization magic angle spinning with dipolar decoupling (CP/MAS), magic angle spinning without dipolar decoupling (MAS), and high-resolution magic angle spinning with gradients (HRMAS). These NMR spectra allow the assignment of the principal 1 H and 13 C signals. The presence of two distinct components (cross-linked β-CD and polymerized epichlorohydrin) in the materials was clearly demonstrated. These polymers were used as sorbents and the resulting NMR spectra are presented and discussed.

2D experiments for the characterization of fluorinated polymers: pulsed-field gradients 1H–19F hetero-COSY and its selective version

Abstract In this paper, we demonstrate the utility of 1 H– 19 F chemical shift correlation 2D NMR experiments for the characterization of fluorinated compounds. 1 H– 19 F hetero-COSY provides much more information compared to the used 1 H– 19 F HMQC and HMBC experiments. We performed 1 H– 19 F hetero-COSY experiment and its selective version, both with pulsed field gradients, to obtain resonance assignments for the characterization of fluoromolecules. These experiments are illustrated by spectra of C 2 F 5 (VDF) 2 I, used here as a model compound, and spectra of the fluorinated terpolymer XC2000S containing vinylidenefluoride (VDF), tetrafluoroethylene (TFE) and allyloxypropandiol (AOPD).

Do Bioactive Peptides Display Native-Like Conformations When Bound to a Solid Support?

High-resolution magic angle spinning (HRMAS) NMR spectroscopy is a very promising technique in the field of solid phase organic chemistry for the analysis of resin-bound compounds, including small molecules and peptides [1,2]. We have successfully applied HRMAS NMR to the conformational study of bioactive peptides covalently attached to different resins [3]. The combination of the swelling and solvation properties of resin-bound peptides with the chemico-physical nature of the solid supports plays a fundamental role in the characterization of such conjugates by HRMAS technique. The secondary structure adopted by the sequence 141GSGVRGDFGSLAPRVARQL159, which delineates the major antigenic site of the viral protein VP1 of foot-and-mouth disease virus (FMDV), bound to three different types of resin, namely MBHA, PEGA and POEPOP, has been determined and compared with that of the same peptide free in solution.