TLC bioautography-guided isolation of antioxidant activity components of extracts from Sophora flavescens Ait.

In this study, a bioactivity-guided isolation of antioxidant activity components of extracts from Sophora flavescens Ait. based on TLC bioautography and column chromatography was provided. The antioxidant activity of S. flavescens Ait. with different origins was evaluated by TLC bioautography, using 2,2-diphenyl-1-picrylhydrazyl radical as a detection reagent. The results showed that S. flavescens Ait. from different origins all expressed antioxidant activity. Then, based on a bioactivity-guided isolation principle, ten antioxidant activity ingredients including trifolirhizin(1), nor-anhydroicaritin(2), calycosin(3), isoxanthohumol(4), trifohrhizin-6′-monoacetate(5), 8-lavandulyl-5,7,4′-trihydroxyflavonol(6), kurarinone(7), sophoraflavanone G(8), maackiain(9) and formononetin(10) were yielded by the separation and purification of column chromatography. Their structures were elucidated by NMR data analysis. The results showed that the primary antioxidant constituents of S. flavescens Ait. were flavonoids, and significantly, prenylated flavonoids with phenolic hydroxyl in ring B had a stronger antioxidant effect than others. The study suggested that TLC bioautography-guided isolation of antioxidant components from S. flavescens Ait. was a kind of simple, rapid and effective means.