A new highly oxygenated pseudoguaianolide from a collection of the flowers of Parthenium hysterophorus

A new highly oxygenated pseudoguaianolide, 8-beta-acetoxyhysterone C, along with the known compounds, parthenin, coronopilin and hysterone C, has been isolated from a collection of the flowers of Parthenium hysterophorus. The structure of the new compound was derived from the extensive studies of its spectral (mainly I D and 2D NMR) data.