Author's Organization：Pharmaceutical Institute, School of Medicine, Tohoku University Pharmaceutical Institute, School of Medicine, Tohoku University Pharmaceutical Institute, School of Medicine, Tohoku University
A new guaianolide C15H20O3, helenium lactone, has been isolated from the common sneezweed, Helenium autumnale (Compositae), cultivated in Japan. The structure of helenium lactone has been shown to be I by chemical and physico-chemical studies of it and its derivatives.
