Guaianolides from the wax of Calocephalus brownii F. Muell. (Compositae)

Abstract

Pseudoivalin, (Ib), previously obtained from Iva microcephala Nutt., and pseudoivalin acetate (Ia) have been isolated from the leaf and stem wax of Calocephalus brownii F. Muell. (family Compositae). A structure for calocephalin, C₁₇H₂₂O₅ a new sesquiterpene lactone also present in the wax, is deduced from spectroscopic evidence.