Flavonoids from the Whole Plants of Leptopus clarkei and Their in vitro Anti‐inflammatory Activities

Our previous researches have showed that the Leptopus genus plants possess significant anti‐tumor and hepatoprotective effects, and over 50 triterpenoids were isolated from these plants. In the present work, the anti‐inflammatory activities of the extracts of four Leptopus genus plants were evaluated before phytochemical experiments. Subsequently, eight flavonoids (1‐8) including two previously undescribed prenylated flavonoids (1‐2) were isolated from the whole plants of Leptopus clarkei. The structures of these new compounds were unequivocally elucidated by HRESIMS and 1D/2D NMR data. Additionally, all isolates were evaluated for their anti‐inflammatory activities. Among these compounds, 1 exhibited moderate anti‐inflammatory activity with IC50 value of 26.5 ± 1.2 μM on NO production in LPS‐induced RAW264.7 cells.