(3aS,4S,4aR,7aR,8R,9aR)-4-hydroxy-4a,8-dimethyl-3-methylene-3,3a,4,4a,7a,8,9,9a-octahydroazuleno[6,5-b]furan-2,5-dione; (3aS,4S,4aR,7aR,8R,9aR)-3,3a,4,4a,7a,8,9,9a-Octahydro-4-hydroxy-4a,8-dimethyl-3-methylene-azuleno[6,5-b]furan-2,5-dione;6?,8?-Dihydroxy-4-oxo-ambrosa-2,11(13)-dien-12-oic acid 12,8-Lactone; [3aS-(3a?,4?,4a?,7a?,8?,9a?)]-3,3a,4,4a,7a,8,9,9a-Octahydro-4-hydroxy-4a,8-dimethyl-3-methylene-azuleno[6,5-b]furan-2,5-dione; (-)-Helenalin; Helenalin A; NSC 85236
