Compound Monograph
Helenalin
A pseudoguaianolide sesquiterpene lactone from arnica, noted for anti-inflammatory but also irritant activity.
Classification
Helenalin is one of the sesquiterpene lactones, part of the terpenoids class. The largest class of plant compounds, built from five-carbon isoprene units — the essential-oil aromatics, resins, bitter principles, saponins, and plant sterols.
Where Does It Come From? (1)
Helenalin is one of the sesquiterpene lactones, found in Arnica. It is flagged as toxic.