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Antioxidant activity of phenolic substances from Betulae folium.
Skálová, Miluše ; Spilková, Jiřina (advisor) ; Kašparová, Marie (referee)
ANTIOXIDANT ACTIVITY OF FENOLIC SUBSTANCES IN BETULAE FOLIUM Miluše Skálová Univerzita Karlova v Praze, Farmaceutická fakulta, Katedra farmakognozie, Heyrovského 1203, 500 05, Hradec Králové Abstract The aim of this study was to investigate antioxidant activity of exctracts of the drug Betulae folium and of buds and leaves of birch collected during the onthogenesis. Also it was appionted content of flavonoids by the method HPLC (High Performance Liquid Chromatography) and it was observed changes during the onthogenesis. The maximal content of caffeic acid in buds was similar like in leaves. The presence of chlorogenic acid was registreted in leaves which were collected in june. High content of the hyperoside was in buds before they have got blossom. and in the young leaves. The next lower maximum was in young leaves, which were collected at the end of may. This value was compareable with the content in dry leaves and also in drug of Betulae folium, which was bought in the pharmacy. The presence of kvercitrin was reminded in buds before blossoming, the similar value was in young leaves, afterthat came a huge decrease of this value. The significant content-increase of kvercitrin was reminded in dried leaves. There are significant differences between the fresh and the dried leaves of the same collection....
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