Electron paramagnetic resonance spin trapping of glutathiyl radicals by PBN in the presence of cyclodextrins and by PBN attached to beta-cyclodextrin.
The reaction of the glutathiyl radical (GS*) with a widely used spin trap N- tert-butyl-alpha-phenylnitrone (PBN) has been studied in the presence of various methylated beta-cyclodextrins and with PBN covalently bound to dimethylated beta-cyclodextrin (PBN-DIMEB) and permethylated beta-cyclodextrin (PBN-TRIMEB). Scavenging rate constants for GS* by PBN were obtained in the presence of randomly methylated cyclodextrin (RAMEB) and PBN-TRIMEB and found to be close to the rate constant previously measured for PBN. RAMEB and 2,6-di- O-Me-beta-cyclodextrin (DIMEB) were found to be the most efficient in the increasing PBN/GS* lifetime, by a factor of 5.5 for RAMEB and 6.8 for DIMEB compared with the lifetime of PBN/GS*. It is concluded that the presence or "attachment of" beta-cyclodextrins does not influence the scavenging rate constant of GS* but it does lead to stabilization of the spin adducts formed.
Polovyanenko
Dmitriy N
DN
International Tomography Center SB RAS, Novosibirsk, Russia.
Marque
Sylvain R A
SR
Lambert
Sandrine
S
Jicsinszky
Laszlo
L
Plyusnin
Victor F
VF
Bagryanskaya
Elena G
EG