Digging Deep for New Compounds from the Compass Plant, Silphium laciniatum

The compass plant, Silphium laciniatum, is an iconic perennial plant of the North American tallgrass prairie. The plants of the tallgrass prairie historically have been subjected to a number of biological and environmental stresses. Among the adaptations developed by S. laciniatum is a large deep taproot. An investigation of the secondary metabolites found in the root of a S. laciniatum specimen has led to the identification of 15 new terpenoids (3–8, 10–17, and 22), which were screened for cytotoxic activity in the NCI-H460 human large-cell lung carcinoma cell line.