Minor Prenylated Flavonoids from the Twigs of Macarangaadenantha and 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 1–3 were 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 IC(50) values in the range of 13.76–22.27 μM. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13659-015-0059-1) contains supplementary material, which is available to authorized users.