(+)-Isoalantolactone470-17-746 % similar Parthenolide20554-84-134 % similar (-)-Xanthatin26791-73-133 % similar Costunolide553-21-933 % similar Helenin546-43-033 % similar (-)-Dehydrocostus lactone477-43-033 % similar Arglabin84692-91-132 % similar