A 14-membered macrolide and isocoumarin derivatives from the cultured lichen mycobionts of Graphis vestitoides.

Spore-derived mycobionts of the crustose lichen Graphis vestitoides collected in Vietnam were cultivated on a malt-yeast extract medium supplemented with 10% sucrose. The investigation of their metabolites resulted in isolation of a novel 14-membered macrolide and a new isocoumarin, together with five known isocoumarin derivatives. Their structures were determined by spectroscopic and chemical means. This is the first instance of isolation of a 14-membered macrolide from a lichen mycobiont.