Minor Prenylated Flavonoids from the Twigs of Macarangaadenanthaand Their Cytotoxic Activity

Three new minor prenylated flavonoids, named macadenanthins A–C (1–3), together with three known ones (4–6), were isolated from the twigs of Macaranga adenantha. Their structures were elucidated on the basis of extensive spectroscopic analysis including NMR, UV and MS. The prenyl moieties in compounds 1–3were further modified by cyclization and hydroxylation. The new compounds were tested for their cytotoxicity against four cancer cell lines (MCF-7, Hep G2, Hela and P388) and showed IC50values in the range of 13.76–22.27 μM.