Three novel benzophenones from Mesua caudata (King) Kosterm. and their cytotoxic activity

To clarify the cytotoxic potential of Mesua caudata (King) Kosterm., three novel benzophenone derivatives, mesucaudatins A–C (1–3), along with one known xanthone compound (4), were found in the stem bark of this plant. The structure determination of all benzophenones (1–3) 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 (1) exhibited potent cytotoxic activity against HeLa cells and MCF-7 cells with IC50 values of 0.76 and 9.29 μM, respectively. Macluraxanthone (4) also showed high activity against HeLa cells (IC50 = 3.96 μM) and moderate activity against MCF-7 cells (IC50 = 10.10 μM).