Isolation and identification of dihydrochrysanolide and its 1-epimer from Chrysanthemum coronarium L.

A new sesquiterpene lactone (1) was isolated with known dihydrochrysanolide derivatives (2 and 3) from the flowers of Chrysanthemum coronarium L., and their structures were identified by spectroscopic data. The stereochemistry of the epimers (1 and 2) was determined from NOESY data and an X-ray crystallographic analysis. The isolated compounds (1-3) were examined for their cytotoxic activity against such human cell lines as A549, PC-3 and HCT-15.