Dienolide

Carda-4,20(22)-dienolide,12,14-dihydroxy-11-oxo-2,3-[(tetrahydro-3-hydroxy-4-methoxy-2H-pyran-3,2-diyl)bis(oxy)]-,[2a(2S,3S,4R),3b,12a]-

5,20-dihydroxy-6,7-epoxy-1-oxo-5-witha-2,24-dienolide