Aromadendrane sesquiterpenes

Braekman, J.C., Daloze, D., Ottinger, R., and Tursch, B. (1977) Chemical studies of marine invertebrates. XXVII. On the absolute configuration of aromadendrane sesquiterpenes from the soft coral Ceapitularia aff. subviridis. Experientia, 33, 993. 

Zhao WM, Ye QH, Dai JQ, Martin MT, Zhu JP (2003) a//o-Aromadendrane- and Picrotox-ane-type Sesquiterpenes from Dendrobium moniliforme. Planta Med 69 1136... 

The only other class of sesquiterpenes isolated from Eremophila is the aromadendrane type which is represented by a single compound, (-r)-spathulenol (94), found in E.cuneifolia (67), E. paisley, E. racemosa and E. drummondii var brevis (14). First isolated from Eucalyptus spathulata (84), this compound has since been found to occur in a broad spectrum of plant genera (85). 

Aromadendrane-type sesquiterpenoids are mainly distributed in Mylia, Plagiochila and Porella species belonging to the Jungermanniales. 2,3-Secoaromadendrane-type sesquiterpenoids have been isolated only from the Plagiochilaceae. A Mylia species contains a unique 1,10-secoaromadendrane-type sesquiterpene. 

Plagiochila are divided into four chemotypes, an aromadendrane-maaliane-type (Type I), a 2,3-secoaromadendrane-type (Type II), a bibenzyl-type (Type III) and one in which the above constituents are absent (Type IV). Pedinophyllum truncatum is chemically quite similar to Type II of Plagiochila, since it elaborates 2,3-secoaromadendrane-type sesquiterpenes, plagiochiline C (48) and plagiochiline H (53) (2(5). Syzygiella liberata is chemically quite different from Plagiochila and Pedinophyllum species (25a). 

Sesquiterpene Ketone of E 72/-l,10-seco-aromadendrane Form, from Mylia taylorii (Liverwort). J. Chem. Soc. Perkin Trans. I 1979, 2652. 

Nabcayama, M., S. Ohira, S. Shinbce, Y. Matsushita, A. Matsuo, and S. Hayashi Synthesis of ( —)-Taylorione, a Sesquiterpene Ketone of 2 -l,10-seco-aromadendrane Skeleton. Chem. Letters 1979, 1245. 

Aromadendranes are dimethylcyclopropane azulenes collectively named after the first isolated molecule of the family (+)-aromadendrane, found as a constituent of the essential oil of Eucalyptus trees. The occurrence of these sesquiterpenes in nature is high, with the higher plants essential oils to be their major sources. Some of the biological properties that have been reported for isolated aromadendranes include antifungal, antibacterial, antifeedant, and cytotoxic activities [75]. 

To demonstrate the power of this concept the sesquiterpene (-)-aromadendran-ediol was synthesized by the same authors using this cascade enamine-iminium activation concept. 

Ciminiello, P., Fattorusso, E., Magno, S., and Mayol, L (1987b) Nitrogenous sesquiterpenes based on aUo-aromadendrane and epi-eudesmane skeletons from the marine sponge Axinella cannabirui. Can.. Chem., 65, 518-522. 

Epimer in 11 was found in the brown alga Taonia lacheana (Tringali et al. 1995). Figure 20.27 Examples of aromadendrane and alloaromadendrane sesquiterpenes. 

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