Compound Monograph
Dihydrohelenalin
A pseudoguaianolide sesquiterpene lactone from arnica and one of its main active and toxic principles; less reactive than helenalin but still a known contact allergen, with anti-inflammatory activity reported in vitro.
Classification
Dihydrohelenalin 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)
Dihydrohelenalin is one of the sesquiterpene lactones, found in Arnica.