Investigation of the South African plant Urginea depressa Baker (Asparagaceae Juss.) for
antiproliferative activity against the A2780 ovarian cancer cell line led to the isolation of the
six new homoisoflavonoids urgineanins A–F (1–6), the two known bufatrienolides 7 and 9,
and the new bufatrienolides urginins B and C (8 and 10). Structures were elucidated based
on analysis of their 1D and 2D NMR spectra, electronic circular dichroism, and mass
spectrometric data. Five of the six new homoisoflavonoids had good antiproliferative activity …