Abstract: The ethanol extract of the stem bark of Fraxinus chinensis Roxb. showed good inhibitory bioactivity against VEGF receptor-1 kinase (IC50: 13.8 μg/mL). In order to find new and bioactive compounds, the chemical constituents of the stem bark of F. chinensis were investigated and two new coumarins, namely 6'-O-sinapinoyl esculin (compound 1) and 6'-O-vanillyl esculin (compound 2), together with eleven known compounds (compounds 3–13) were isolated.The structures of the two new compounds were identified by their physicochemical properties and spectral analysis, particularly one- and two-dimensional nuclear magnetic resonance spectral methods. The known compound, oleuropein (compound 11), exhibited moderate activity (IC50: (8.7 ± 1.3) μmol/L) to inhibit VEGF receptor-1 kinase.

Key words: cernuasides A and B, Pulsatilla cernua, Ranunculaceae, triterpenoid saponin.