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

► Isolation and structure elucidation of new alkylbenzoquinones. ► ardisiaquinone J (1) and K (2) exhibited considerable antiproliferative activity. ► ardisiaquinone K (2) exerted a moderate free radical scavenging effect on DPPH-assay.