Cytotoxic prenylated bibenzyls and flavonoids from Macaranga kurzii.

One unique prenylated bibenzyl, kurzphenol A (1), two new prenylated flavonoids, kurzphenols B and C (2 and 3), as well as fourteen known compounds (4-17) were isolated from the twigs of Macaranga kurzii. Compound 1 was the first example of prenylated bibenzyl which possesses a benzofuran ring. All the known compounds were isolated from M. kurzii for the first time. Their structures were elucidated on the basis of extensive spectroscopic interpretation. Compounds 1-17 were tested for their cytotoxicity against A-549 and Hep G2 cancer cell lines and showed IC50 values in the range of 9.76-30.14 μg/mL.