Two novel biphenyl dimers from the heartwood of Caesalpinia sappan

Two novel biphenyl dimers, caesappanin A (1) and B (2), were isolated from the ethanol extract of the heartwood of Caesalpinia sappan. Their structures were elucidated on the basis of spectroscopic data including IR, HRESIMS, 1D and 2D NMR. Preliminary bioassays showed that compound 1 possessed potent cytotoxic effects against 4 cell lines including HCT-8, BGC-823, A549 and A2780 with IC50 between 1.67 μM and 4.88 μM.

Graphical abstractTwo novel biphenyl dimers, 1 and 2, were isolated from the heartwood of Caesalpinia sappan. Their structures were elucidated on the basis of spectroscopic data.Figure optionsDownload full-size imageDownload as PowerPoint slide