Chemical composition and cytotoxicity of oils and eremophilanes derived from various parts of Eremophila mitchellii Benth. (Myoporaceae)

The biologically active wood, leaf, branch and root oils of Eremophila mitchellii (Benth.) were investigated in detail. 9-Hydroxy-1,7(11),9-eremophilatrien-8-one (9), and five previously identified eremophilane sesquiterpenes and the zizaene sesquithuriferone were isolated and elucidated. [Display omitted] ► E. mitchellii contains eremophilanes; a class of rare bicyclic sesquiterpenes. ► The chemical composition of the wood, leaf, root and branch oils of E. mitchellii. ► Isolation and elucidation of sesquithuriferone and six eremophilanes. ► The eremophilanes inhibit P388D1 cancer cell growth in vitro. ► A revision of the NMR and mass spectroscopic data for the eremophilanes. A detailed investigation of the wood, leaf, branch and root oil of Eremophila mitchellii (Benth.) was carried out by a combination of GC–FID, GC–MS and NMR. The wood oil was composed predominantly of eremophilanes, a rare class of biologically active, bicyclic sesquiterpenoids. The root oil was also found to contain the eremophilanes together with the zizaene sesquiterpene, sesquithuriferone. 9-Hydroxy-1,7(11),9-eremophilatrien-8-one and the known 1(10),11-eremophiladien-9-one (eremophilone), 9-hydroxy-7(11),9-eremophiladien-8-one (2-hydroxyeremophilone), 8-hydroxy-11-eremophilen-9-one (santalcamphor), 8-hydroxy-10,11-eremophiladien-9-one, sesquithuriferone and 8-hydroxy-1,11-eremophiladien-9-one were purified and elucidated by NMR. Three approaches to the purification of the major eremophilanes from the wood oil are described. (+) Spathulenol, α-pinene, globulol, viridiflorene were the major constituents of the leaf oil. All of the essential oils and the eremophilanes exhibited cytotoxicity against P388D1 mouse lymphoblast cells in-vitro.