Cytotoxic Prenylated Polyphenolic Compounds from Maackia amurensis Root Bark

Abstract

Two new prenylated flavanones, isomaackiaflavanone A (1), isomaackiaflavanone B (2) and a new prenylated stilbene maackiastilbene (3), along with five known flavanones were isolated from the root bark of Maackia amurensis using repeated column chromatography on silica gel, Sephadex LH-20 and octadecyl silica (ODS-A) sorbents. The structures of the new compounds were elucidated by HPLC–PDA–MS, HR-ESI-MS, 1H, 13C, 1H–1H COSY, HSQC, ROESY and HMBC NMR analyses. The cytotoxicity of compounds 1–2, 4–8 against two human cancer cell lines HeLa and SK-MEL-5 was tested using the MTS method. Compounds 4, 6 and 8 showed the strongest cytotoxic activity among the compounds tested with IC50 values of 6.5, 8.8 and 7.7 μM, against SK-MEL-5 cells and 8.2, 18.8 and 12 μM against HeLa cells, respectively.