Four New 1,4‐Benzoquinone Derivatives and One New Coumarin Isolated from Ardisia gigantifolia

Abstract Four new 1,4‐benzoquinone derivatives, belamcandaquinones J ( 1 ), K ( 2 ), L ( 3 ), and M ( 4 ), and one new coumarin, 5 , were isolated from the rhizome of Ardisia gigantifolia. Their structures were established by means of spectroscopic methods, and their cytotoxicity was tested in vitro against the cell lines PC‐3, EMT6, A549, Hela, RM‐1, and SGC7901. In comparison with cisplatin, compound 5 showed strong cytotoxicity with an IC 50 value of <30 μ M against the cell lines PC‐3 and A549. Compounds 1 – 4 showed no cytotoxicity against all cell lines.