Characterization of new aza-sesquiterpenoids from the fungus Clavicorona Divaricata

Mushrooms have proved to be a rich source of secondary metabolites with unusual structures as well as interesting biological activities. Despite their potential for drug development, few bioactive metabolites have been reported from mushrooms as compared with higher plants and microbes. In our screening project on bioactive metabolites of Basidiomycetes we have investigated the metabolites produced by the fungus Clavicorona divaricata in MPG agar cultures and isolated divaricatine A and B together with the nor-sesquiterpenoids tsugicoline L and M. Successively, the fermentation of the fungus in different conditions, gave rise to complex mixtures, from which new aza-sesquiterpenoids were isolated. The poster describes the isolation, structure elucidation and absolute configuration assessment of these novel metabolites The skeleton of these compounds was never found before among the sequiterpenes of protoilludane origin. A possible mechanism of their formation is also suggested. The new metabolites showed a weak antibacterial activity against Bacillus cereus and Sarcinea lutea (50µg/disc), and inhibited the growth of Lepidum sativum (After 48 h, the inhibition of the root elongation was 85, 91 and 72%, respectively).