Alpha-phenyl-N-tert-butylnitrone-type derivatives bound to beta-cyclodextrins: syntheses, thermokinetics of self-inclusion and application to superoxide spin-trapping.
alpha-Phenyl-N-tert-butylnitrone (PBN) derivatives bound to beta-cyclodextrin derivatives have been synthesized. Inclusion of the PBN group into the beta-cyclodextrin moiety is host- and temperature-dependent. In the case of the nitrone linked to permethylated cyclodextrin (Me3CD-PBN), the thermokinetic parameters are in favour of a slow chemical exchange between a tight and a loose complex. In contrast, 2,6-di-O-Me-beta-cyclodextrin-grafted PBN (Me2CD-PBN) exists either in a fast exchange or as a strongly self-associated complex. The covalent cyclodextrin-PBN compounds have been used to trap carbon and oxygen-centred free radicals. The self-associated forms of the beta-CD-spin-traps are compatible with effective spin-trapping, affording spin-adducts with enhanced EPR signal intensities relative to noncovalent CD-nitrone systems or the nitrone alone. This kind of cyclodextrin-bound nitrone is the first type of covalent supramolecular spin-trap and should open new possibilities for the study of biological free radicals in vivo.
Bardelang
David
D
UMR 6517 CNRS et Aix-Marseille Université, Faculté de Saint-Jérôme, Case 521, Avenue Escadrille Normandie Niemen, 13397, Marseille Cedex 20, France. david.bardelang@nrc-cnrc.gc.ca
Charles
Laurence
L
Finet
Jean-Pierre
JP
Jicsinszky
Laszlo
L
Karoui
Hakim
H
Marque
Sylvain R A
SR
Monnier
Valérie
V
Rockenbauer
Antal
A
Rosas
Roseline
R
Tordo
Paul
P
D003497:Cyclic N-Oxides / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D019097:Spin Trapping; D013481:Superoxides / Q000032:analysis*; D047392:beta-Cyclodextrins / Q000737:chemistry
D003497:Cyclic N-Oxides; D047392:beta-Cyclodextrins; D013481:Superoxides; C029217:phenyl-N-tert-butylnitrone