New flavonoids from the aerial part of Bupleurum chinense DC

Four new flavonoids (1-4) and fourteen known compounds (5-18), were isolated from the aerial part of Bupleurum chinense DC. The structural determination of the new flavonoids was accomplished using comprehensive spectroscopic methods, including 1D and 2D NMR spectra with references to the literatures, as well as high-resolution mass spectrometric analysis. The anti-proliferative activities of the flavonoids (1-18) against HeLa cells were evaluated using the MTT assay with cisplatin as the positive control.