RESUMO
An X-band (9.3 GHz) electron paramagnetic resonance (EPR) spectroscopy was used to examine the free radical scavenging activity of the following infusions, which were nonirradiated and exposed to UVA: root of Asparagus racemosus and herbs of Mitchella repens, Cnicus benedictus L., Galega officinalis L., and Eupatorium cannabinum L. The plant materials for obstetrics applications were chosen for analysis. The aims of these studies were to compare the free radical scavenging ability of the tested infusions and to determine the influence of UVA irradiation of the plant materials on interactions of these infusions with free radicals. Both the magnitude and kinetics of the interactions of the infusions with the model DPPH free radicals were examined. The ability to quench the free radicals for the examined plant infusions increases in the following order: Asparagus racemosus (root) < Mitchella repens (herb) < Cnicus benedictus L. (herb) < Galega officinalis L. (herb) < Eupatorium cannabinum L. (herb). The analyzed infusions differ in the kinetics of the interactions with free radicals. The fastest interactions with free radicals characterize the infusions of Galega officinalis L. herb and Eupatorium cannabinum L. herb. The infusion of Mitchella repens herb interacts with free radicals in the slowest way. UVA radiation reduces the antioxidant interactions of all tested infusions, especially the infusion of Eupatorium cannabinum L. herb, which should be protected against UVA radiation during storage. The weakest decrease of free radical scavenging activity was observed for the infusion of the root of Asparagus racemosus exposed to UVA radiation. UVA radiation affected the speed of the free radical interactions of the infusions, depending on the type of plant materials. EPR spectroscopy is useful to examine the free radical scavenging activity of plant infusions, which is helpful to find effective antioxidants for applications in obstetrics and their optimal storage conditions.
RESUMO
Rosuvastatin was thermally sterilized at temperatures 160°C during 120 min, 170°C during 60 min and 180°C during 30 min, according to Polish pharmacopoeia norms. Free radicals formed in the heated rosuvastatin samples were examined by electron paramagnetic resonance (EPR) spectroscopy. The best conditions of thermal sterilization of rosuvastatin were searched. EPR spectra were measured for the analyzed drug independent on heating temperature. Decrease of free radical concentrations in rosuvastatin with increasing of heating temperature was stated. The optimal conditions for thermal sterilization of rosuvastatin were temperature 180°C and heating time of 30 min and resulted in the lowest free radical concentration. The changes of amplitudes (A) and linewidths (∇Bpp) of EPR spectra of the heated rosuvastatin were characteristic for homogeneous broadening EPR lines. Slow spin-lattice relaxation processes existed in the all rosuvastatin samples. The confirmation of usefulness of electron paramagnetic resonance spectroscopy in pharmacy was presented.