Antiproliferative metabolites from the Northern African endemic plant Daucus virgatus (Apiaceae).

Chemical analysis of the dichloromethane fraction obtained from aerial parts of the Northern African endemic plant Daucus virgatus led to the isolation of three previously undescribed sesquiterpenoids, namely the daucane vaginatin B, a eudesmane and the elemane elemavirgolide, along with five known metabolites. The structures of these compounds were determined by a detailed MS and NMR analysis and they were evaluated for antiproliferative activity against three human cell lines, A375 (melanoma), MCF-7 (breast adenocarcinoma), and HACAT (keratinocyte). The phytoalexin 6-methoxymellein revealed a previously unreported antiproliferative activity, while the eudesmane and the elemane derivatives exhibited a selective activity (SI = 11.1 and 3.3, respectively) against melanoma tumor cell lines.