ent-Kaur-16-en-19-oic acid, a KB cells cytotoxic diterpenoid from Elaeoselinum foetidum.

Toxic and cytotoxic activities of the toxic plant Elaeoselinum foetidum (Apiaceae) were evaluated using the brine shrimp toxicity (BST) and KB cell cytotoxicity assays. The active chloroform extract was subjected to a bioactivity-directed fractionation, monitored by the BST assay, that led to the isolation of the diterpenoid ent-kaur-16-en-19-oic acid. This compound was potent against the brine shrimp (LC(50) = 4.8 microg/mL) and KB cells (IC(50) = 1.6 microg/mL).