Five sesquiterpene lactones were isolated from Michelia champaca root
bark. One of these, michampanolide ylene-13-oxatricyclo[8,3,0,0,3,b]tr
idecan-12-one), possessed a new skeleton, while two others, 8-acetoxyp
arthenolide and magnograndiolide, were isolated for the first time fro
m M. champaca.