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The depsidones hypophysciosporin (methyl 2-chloro-3,8-dihydroxy-1,4,6,9-tetramethyl-11-oxo-11H-dibenzo[ b,e ][1,4]dioxepin-7-carboxylate) (9) and 3-O-methylhypophysciosporin (methyl 2-chloro-8-hydroxy-3-methoxy-1,4,6,9-tetra-11-oxo-11H-dibenzo[ b,e ][1,4]dioxepin-7-carboxylate)(10) have been isolated from the lichen Erioderma phaeorhizum and the structures of these metabolites have been established by comparison with synthetic material. In addition the chroman, vitamin E acetate (14), has been isolated from Erioderma tomentosum, the first reported occurrence of this compound in a lichen.

The depsidones norpannarin (4) and norargopsin (5) have been prepared by unambiguous synthesis and shown to co-occur with nordechloropannarin (7), pannarin (3) and argopsin (2) in Erioderma chilense.

The new depsides 3-chlorostenosporic acid (2), 3-chloroperlatolic acid (3) and subsphaeric acid (24) have been detected in Dimelaena lichens and the structures of the metabolites have been established by unambiguous synthesis. Wrightiin (methyl 3-chloroevernate) (21), a depside from Erioderma wrightii, has also been synthesized by using similar methodology.

A chemosyndrome of para- depsides based on methyl 4-O-demethylbarbatate (3) has been detected in Erioderma lichens and the structures of the metabolites have been established by unambiguous syntheses. New depsides include methyl 5-chloro-4-O-demethylbarbatate (4), methyl eriodermate (5), methyl 2'-0-methyleriodermate (6), methyl 2-O-methyleriodermate (7), methyl 4-O-methyleriodermate (8) and methyl 2,2'-di-O-methyleriodermate (9).