Veluflavanones A-P, Cytotoxic Geranylated Flavanones from Dalbergia velutina Stems.

Sixteen new geranylated flavanones, named veluflavanones A-P (1-16), and a known analogue (17), were isolated from Dalbergia velutina. The chemical structures of 1-17, as well as their absolute configurations, were determined by spectroscopic analysis and experimental ECD data. All isolated compounds were tested for their cytotoxicity against five human cancer cell lines. Compound 9 showed cytotoxicity toward KB, HeLa S3, and MCF-7 cells with IC₅₀ values of 9.9, 8.1, and 10.0 μM, respectively. In addition, compounds 10, 11, 14, and 16 exhibited selective cytotoxicity against HeLa S3 cells with IC₅₀ values of 6.6-9.9 μM.