Eremophilane-type sesquiterpenes from cultured lichen mycobionts of Sarcographa tricosa.

Spore-derived mycobionts of the crustose lichen Sarcographa tricosa were cultivated on a malt-yeast extract medium supplemented with 10% sucrose. Chemical investigation of the cultivated colonies led to isolation of three eremophilane-type sesquiterpenes, 3-epi-petasol (1), dihydropetasol (2) and sarcographol (3), together with six known eremophilanes and ergosterol peroxide. These structures were elucidated by spectroscopic and chemical methods. This is the first report of eremophilane-type sesquiterpenes from the cultured mycobionts of lichen.