The structure determination of two related eremophilone dimers

Abstract

The first representatives of a new class of eremophilone dimers have been isolated from the wood oil of Eremophila mitchelli and shown by a combination of spectroscopic and X-ray techniques to possess the unusual 1-(8',8'a-dimethylperhydronaphthalen-2'-yl)-1,4,5,10a-tetramethylperhydroanthracene carbon skeleton. These two natural products are the first C30 compounds to be isolated from any member of the genus Eremophila.

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

“…Their isolation and characterisation is complicated because they share similar molecular weights and many were found to co-elute with the major compounds throughout HPLC (both NP and RP) and GC-MS (both polar and apolar systems). Several structural analogues of the eremophilones have been reported in the literature including the aldehyde 2 (Abel and Massy-Westropp, 1985), isoeremophilone (11) (Chetty and Zalkow, 1969), alloeremophilone (12) (Bates and Paknikar., 1966) and the dimers 7 and 8 (Lewis et al, 1979(Lewis et al, , 1982. The analogues, if present, appear to be very minor constituents.…”

Natural disesquiterpenoids

“…105 Further research resulted in the isolation of two more dimers, 105-106, possessing the same skeleton as 104. 106 A symmetrical eremophilane dimer 107 was identified as a component of the rhizomes of Farfugium japonica. 107 The dimers virgaurins A-C 108-110, 108-111 111-112 104 and virgaurols A-B 113-114 112 were obtained from the same species, Ligularia virgaurea, collected from a different district in China.…”

Mitchellenes A–E, Cyclic Sesquiterpenes from the Australian Plant Eremophila mitchellii

“…1,5 The natural products isolated from this species include eremophilone [15][16][17] and its derivatives. 4,[18][19][20][21] Oil extracts from this plant have been extensively studied due to their termiticidal and insecticidal activities, [21][22][23][24] and one study has found the wood oil to possess antimicrobial activity. 25 In this study, E. mitchellii was investigated as a potential source of large quantities ( > 200 mg) of the previously isolated compound, 14-hydroxy-6,12-muuroloadien-15-oic acid (6).…”