title: Effect of UV irradiation onEchinaceae purpureaeinteractions with free radicals examined by an X-band (9.3 GHz) EPR spectroscopy.
abstract: The effect of UVA (315-400 nm) irradiation onEchinaceae purpureaeinteractions with free radicals was examined by the use of electron paramagnetic resonance (EPR) spectroscopy. The changes of antioxidant properties ofE. purpureaewith time of UV irradiation from 10 to 110 min (10 min steps) were determined. DPPH as the paramagnetic reference was used in this study. Changes of EPR signals of the reference after interactions with nonirradiated and UV-irradiatedE. purpureaewere detected. Interactions of the testedE. purpureaesamples caused decrease of the EPR signal of DPPH as the result of its antioxidant properties. The decrease of the amplitude of EPR line of DPPH was lower for interactions with UV-irradiatedE. purpureae. EPR examination confirmed antioxidant properties ofE. purpureae. The weaker antioxidant properties ofE. purpureaeafter UV irradiation were pointed out.E. purpureaeshould be storage in the dark. The tests bring to light usefulness of electron paramagnetic resonance with microwave frequency of 9.3 GHz (an X-band) in examination of storage conditions of pharmacological herbs.
authors.affiliation: Department of Biophysics, School of Pharmacy with the Division of Laboratory Medicine, Medical University of Silesia in Katowice, Jedności 8, 41-200 Sosnowiec, Poland.
authors.forename: Paweł
authors.initials: P
authors.lastname: Ramos
authors.affiliation: Department of Biophysics, School of Pharmacy with the Division of Laboratory Medicine, Medical University of Silesia in Katowice, Jedności 8, 41-200 Sosnowiec, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Pilawa
keywords: Antioxidant; EPR spectroscopy; Echinaceae purpureae; Free radicals; UV irradiation