Structurally diverse isoflavones from Ficus altissima Blume and their potential antiproliferative effects

The stems (including barks and woods) and leaves of Ficus altissima Blume were chemically studied. This work caused the discovery of a new isoflavone, ficusaltissine A (1), alongside seven recognised analogues (2-8). Ficusaltissine A (1) was fully characterised by spectral methods and the recognised isolates (2-8) were assigned by reference to published spectral data. The in vitro antiproliferative effects of compounds 1-8 were assessed against a panel of five human cancer cell lines. The tested isoflavones showed strong growth‑suppressive properties. A range of 0.22 ± 0.03 to 16.58 ± 0.16 μM was obtained for the IC₅₀ values of compounds 1-8. Notably, ficusaltissine A (1) exhibited superior potency against HL-60 cells (IC₅₀ = 0.22 ± 0.03 μM), surpassing the reference drug doxorubicin (IC₅₀ = 0.32 ± 0.05 μM). These findings indicated that these these isoflavones derived from F. altissima were an exciting source for the development of new anticancer drug scaffolds.