helenalin
noun
hel·e·nalin
ˌheləˈnalə̇n,
-nāl-
plural -s
: a poisonous bitter crystalline compound C15H18O4 that is the active principle of sneezeweed
Word History
Etymology
helen- (from New Latin Helenium, genus name of the sneezeweed Helenium autumnale) + -al- (from New Latin autumnale, specific epithet of the sneezeweed Helenium autumnale) + -in