Airlanggins A-B, two new isoprenylated benzofuran-3-ones from the stem bark of <i>Calophyllum soulattri</i>

<p>Two new isoprenylated benzofuran 3-ones, airlanggin A (<b>1</b>) and B (<b>2</b>) along with two known xanthones, ananixanthone (<b>3</b>) and trapezifolixanthone (<b>4</b>) were isolated from the stem bark of <i>Calophyllum soulattri</i>. Structures of all the compounds were elucidated using extensive spectroscopic methods, including UV, IR, HRESIMS, 1D and 2D NMR. Compounds <b>1</b>–<b>4</b> were evaluated for their cytotoxicity against P-388 cells, showing that compound <b>3</b> was the most active with IC₅₀ 0.68 μg/mL and compound <b>1</b> showed moderate activity with IC₅₀ 5.80 μg/mL.