Further new depsones from the lichen Pertusaria truncata.

Abstract

The new depsones, hyperpicrolichenic acid (I, R1 = pentyl, R2 = heptyl), isohyperpicrolichenic acid (I, R1 = heptyl, R2 = pentyl), megapicrolichenic acid (I, R1 = heptyl, R2 = nonyl) isomegapicrolichenic acid (I, R1 = nonyl, R2 = heptyl) and isosubpicrolichenic acid (I, R1 = pentyl, R2 = Pr) have been shown to co-occur with picrolichenic acid (I, R1 = R2 = pentyl) in the lichen Pertusaria truncata. The assigned structures were confirmed by unambiguous synthesis.