US8609858: Spiro derivatives of parthenin as novel anticancer agents

The invention relates to novel spiro derivatives of parthenin prepared by the dipolar cycloaddition of various dipoles viz, benzonitrile oxides, nitrones, azides, nitrile ylide diazoalkane, nitrile imide, ozone, azomethine imides, azomethine ylides etc. with exocyclic double bond of C ring (?-methylene-?-butyrolactone). Representative compounds have been screened for their anticancer activity against different cancer cell lines. ICs0 value of these analogues varies between 4.3 µM to 93 µM. A mechanistic correlation of their anticancer activity has been described. The results of the cytotoxicity test of the compounds studies indicated that the ?, ?-unsaturated ketonic moiety in parthenin plays an important role in the maintenance of the high level of cytotoxicity.