Three novel benzophenones from <i>Mesua caudata</i> (King) Kosterm. and their cytotoxic activity

To clarify the cytotoxic potential of <i>Mesua caudata</i> (King) Kosterm., three novel benzophenone derivatives, mesucaudatins A-C (<b>1-3</b>), along with one known xanthone compound (<b>4</b>), were found in the stem bark of this plant. The structure determination of all benzophenones (<b>1-3</b>) was carried out by 1D (¹H,¹³C) or 2D (HMQC, HMBC) NMR spectroscopy, and high-resolution MS data. All isolates from this plant were first tested for cytotoxicity against cervical (HeLa) and breast cancer (MCF-7) cells. Mesucaudatin A (<b>1</b>) exhibited potent cytotoxic activity against HeLa cells and MCF-7 cells with IC₅₀ values of 0.76 and 9.29 μM, respectively. Macluraxanthone (<b>4</b>) also showed high activity against HeLa cells (IC₅₀ = 3.96 μM) and moderate activity against MCF-7 cells (IC₅₀ = 10.10 μM).