(-)-Parthenolide 20554-84-1 AIDS-007764 AIDS007764 Germacra-1(10),11(13)-dien-12-oic acid, 4,5.alpha.-epoxy-6.beta.-hydroxy-, gamma.-lactone NSC157035 Oxireno[9,10]cyclodeca[1,2-b]furan-9(1aH)-one, 2,3,6,7,7a,8,10a,10b-octahydro-1a,5-dimethyl-8-methylene-, (1aR,4E,7aS,10aS,10bS)- Parthenolide