Cytotoxicities of two new isoflavanes from the roots of Dalbergia velutina.

Two new isoflavanes, dalvelutinanes A (1) and B (2), along with three known isoflavanes (3-5) were isolated from the roots of Dalbergia velutina. Their chemical structures, including their absolute configurations, were determined by spectroscopic analysis (1D and 2D NMR, HRESIMS, and CD). All isolated compounds were evaluated for their in vitro cytotoxicities against five human cancer cell lines (KB, HeLa-S3, MCF-7, HepG-2, and HT-29). Compound 5 showed significant cytotoxicity against all of the tested cancer cell lines, with IC50 values in the range 3.47-9.76 µM. In addition, compound 3 showed significant cytotoxicity against the KB and HeLa-S3 cells, with IC50 values of 8.29 and 9.54 µM, respectively, and compound 2 showed significant cytotoxicity against the MCF-7 cell line, with an IC50 value of 4.69 µM.