Alkylbenzoquinones with antiproliferative effect against human cancer cell lines from stem of Ardisia kivuensis

Two new alkylbenzoquinone derivatives, named as ardisiaquinone J (1) and K (2) were isolated from the MeOH extract of the stem of Ardisia kivuensis Taton (Myrsinaceae), together with the known lupeol and β-sitosterol. Their structures were elucidated on the basis of spectroscopic analysis and comparison with authentic samples. The new compounds exhibited considerable antiproliferative activity against Ishikawa, HeLa, MCF7 and A431 cell lines with IC50 values between 6.64 and 15.40 μM. In addition, compound 2 exerted a moderate free radical scavenging effect on DPPH-assay. © 2011 Phytochemical Society of Europe.