[Antioxidant activity of different phenolic fractions separated from Euphrasia rostkoviana Hayne]

Euphrasia rostkoviana Hayne (Eyebright) is a valuable part of the traditional folk medicine as an anti-inflammatory herb since centuries. Since oxidative stress may underlie as a key feature of inflammatory process, the methanolic extract ofEuphrasia rostkoviana Hayne (eyebright) and its methanolic fractions were evaluated for antioxidant activity by the use of ABTS and DPPH decolorization assays. Fractionation of the Soxhlet extract was accomplished by polyamide column chromatography. For chemical characterisation HPLC-DAD-MS/MS was used. Fraction 1., dominated by a glycosilated caffeic acid derivative, exhibited the strongest antioxidant activity in DPPH and ABTS assays, IC50: 11.88 microg/ml and 4.24 microg/ml, respectively, which are notable results if compared to the investigated standards. Fractions of flavonoid glycosides proved to have similarly strong, but lower effect. The scavenging reaction of the two radical cations were comparable, IC50 results were differing, while precision not.